We report on the fabrication of a chirped, phase mask that was used to create a fiber Bragg grating(FBG)device for the compensation of chromatic dispersion in longhaul optical transmission networks.Electron beamlithography was used to expose the grating onto a resist-coated quartz plate. After etching, this phase mask was used to holographically expose an index grating into the fiber core [K. O. Hill, F. Bilodeau, D. C. Johnson, and J. Albert, Appl. Phys. Lett.62, 1035 (1993)]. The linear increase in the grating period, “chirp,” is only 0.55 nm over the 10 cm grating. This is too small to be defined by computer aided design and a digital deflection system. Instead, the chirp was incorporated by repeatedly rescaling the analog electronics used for field size calibration. Special attention must be paid to minimize any field stitching and exposure artifacts. This was done by using overlapping fields in a “voting” method. As a result, each grating line is exposed by the accumulation of three overlapping exposures at 1/3 dose. This translates any abrupt stitching error into a small but uniform change in the line-to-space ratio of the grating. The phase mask was used with the double-exposure photoprinting technique [K. O. Hill, F. Bilodeau, B. Malo, T. Kitagawa, S. Thériault, D. C. Johnson, J. Albert, and K. Takiguchi, Opt. Lett. 19, 1314 (1994)]: a KrF excimer laser holographically imprints an apodized chirped Bragg grating in a hydrogen loaded SMF-28 optical fiber. Our experiments have demonstrated a spectral delay of −1311 ps/nm with a linearity of +/−10 ps over the 3 dB bandwidth of the resonant wavelength of the FBG. The reflectance, centered on 1550 nm, shows a side-lobe suppression of −25 dB. Fabrication processes and optical characterization will be discussed.
The effective indices of the cladding modes of optical fibers depend on the refractive index of the medium surrounding the fiber. We show experimentally and theoretically that while cladding modes with similar effective indices normally have similar refractometric sensitivities, the addition of a 50 nm thick gold sheath enhances the sensitivity of some EH modes by more than one order of magnitude while nearly completely suppressing the sensitivity of neighbouring HE modes (by three orders of magnitude, down to insignificant levels). A differential sensitivity of ∼1000 nm/(refractive index unit) is experimentally reported between adjacent EH and HE grating resonances.
The observation of four-wave mixing (FWM) in single-walled carbon nanotubes (SWCNTs) deposited around a tilted fiber Bragg grating (TFBG) has been demonstrated. A thin, floating SWCNT film is manually wrapped around the outer cladding of the fiber and FWM occurs between two core-guided laser signals by TFBG-induced interaction of the core mode and cladding modes. The effective nonlinear coefficient is calculated to be 1.8 10 3W -1Km -1. The wavelength of generated idlers is tunable with a range of 7.8 nm.
A photolithographic method is described for fabricating refractive index Bragg gratings in photosensitive optical fiber by using a special phase mask grating made of silica glass. A KrF excimer laser beam (249 nm) at normal incidence is modulated spatially by the phase mask grating. The diffracted light, which forms a periodic, high-contrast intensity pattern with half the phase mask grating pitch, photoimprints a refractive index modulation into the core of photosensitive fiber placed behind, in proximity, and parallel, to the mask; the phase mask grating striations are oriented normal to the fiber axis. This method of fabricating in-fiber Bragg gratings is flexible, simple to use, results in reduced mechanical sensitivity of the grating writing apparatus and is functional even with low spatial and temporal coherence laser sources.
Silica-based thin-film multilayers are investigated as a means to enhance the effective second-order nonlinearity induced in silica glass structures by corona poling. Structures consisting of phosphorus-doped and undoped silica glass layers exhibit second harmonic generation (SHG) that is higher by an order of magnitude compared to the SHG in bulk silica glass poled under the same conditions. When the poled structure consists of two multilayered stacks separated in space, the stacks exhibit comparable poling-induced nonlinearities. This result suggests that the poling voltage is divided between the two stacks such that simultaneous poling of multiple regions within the sample is realized.
Photobleaching of optical absorption bands in the 5 eV region and the creation of others at higher and lower energy have been examined in the case of ArF (6.4 eV) and KrF (5 eV) excimer laserirradiation of 3GeO2:97SiO2glasses. We report a difference in the transformation process of the neutral oxygen monovacancy and also of the germanium lone pair center (GLPC) into electron trap centers associated with fourfold coordinated Ge ions and Ge-E′ centers when we use one or the other laser. Correlations between absorption bands and electron spin resonance signals were made after different steps of laser irradiation. It was found that the KrF laser generates twice as many Ge-E′ centers as the ArF laser for the same dose of energy delivered. The main reason for this difference is found to be the more efficient bleaching of the GLPC (5.14 eV) by the KrF laser compared to that by the ArF laser.
Samples of synthetic fused silica have been implanted at room temperature with silicon ions of energy 1.5 MeV. Fluences ranged from 1011 to 1013 cm−2. Samples were probed using variable‐energy positron annihilation spectroscopy. The Doppler‐broadening S parameter corresponding to the implanted region decreased with increasing fluence and saturated at a fluence of 1013 cm−2. It is shown that the decrease in the S parameter is due to the suppression of positronium (Ps) which is formed in the preimplanted material, due to the competing process of implantation‐induced trapping of positrons. In order to satisfactorily model the positron data it was necessary to account for positron trapping due to defects created by both electronic and nuclear stopping of the implanted ions. Annealing of the 1013 cm−2 sample resulted in measurable recovery of the preimplanted S parameter spectrum at 350 °C and complete recovery to the preimplanted condition at 600 °C. Volume compaction was also observed afterimplantation. Upon annealing, the compaction was seen to decrease by 75%.
We address the problem of discovering routes in strongly connected planar geometric networks with directed links. Motivated by the necessity for establishing communication in wireless ad hoc networks in which the only information available to a vertex is its immediate neighborhood, we are considering routing algorithms that use the neighborhood information of a vertex for routing with constant memory only. We solve the problem for three types of directed planar geometric networks: Eulerian (in which every vertex has the same number of incoming and outgoing edges), Outerplanar (in which a single face contains all vertices of the network), and Strongly Face Connected, a new class of geometric networks that we define in the article, consisting of several faces, each face being a strongly connected outerplanar graph.
We test for the presence of time-varying parameters (TVP) in the long-run dynamics of energy prices for oil, natural gas and coal, within a standard class of mean-reverting models. We also propose residual-based diagnostic tests and examine out-of-sample forecasts. In-sample LR tests support the TVP model for coal and gas but not for oil, though companion diagnostics suggest that the model is too restrictive to conclusively fit the data. Out-of-sample analysis suggests a random-walk specification for oil price, and TVP models for both real-time forecasting in the case of gas and long-run forecasting in the case of coal.
This article draws on Margaret Radin's theorization of 'contested commodities' to explore the process whereby informal housing becomes formalized while also being shaped by legal regulation. In seeking to move once-informal housing into the domain of official legality, cities can seldom rely on a simple legal framework of private-law principles of property and contract. Instead, they face complex trade-offs between providing basic needs and affordability and meeting public-law norms around living standards, traditional neighbourhood feel and the environment. This article highlights these issues through an examination of the uneven process of legal formalization of basement apartments in Vancouver, Canada. We chose a lengthy period-from 1928 to 2009-to explore how basement apartments became a vital source of housing often at odds with city planning that has long favoured a low-density residential built form. We suggest that Radin's theoretical account makes it possible to link legalization and official market construction with two questions: whether to permit commodification and how to permit commodification. Real-world commodification processes-including legal sanction-reflect hybridization, pragmatic decision making and regulatory compromise. The resolution of questions concerning how to legalize commodification are also intertwined with processes of market expansion.
The new renewable fuels standard (RFS 2) aims to distinguish corn-ethanol that achieves a 20% reduction in greenhouse gas (GHG) emissions compared with gasoline. Field data from Kim et al. (2009) and from our own study suggest that geographic variability in the GHG emissions arising from corn production casts considerable doubt on the approach used in the RFS 2 to measure compliance with the 20% target. If regulators wish to require compliance of fuels with specific GHG emission reduction thresholds, then data from growing biomass should be disaggregated to a level that captures the level of variability in grain corn production and the application of life cycle assessment to biofuels should be modified to capture this variability.
In this special issue of Nova Religio four historians of medieval and early modern Christianities offer perspectives on basic conceptual frameworks widely employed in new religions studies, including modernization and secularization, radicalism/violent radicalization, and diversity/diversification. Together with a response essay by J. Gordon Melton, these articles suggest strong possibilities for renewed and ongoing conversation between scholars of "old" and "new" religions. Unlike some early discussions, ours is not aimed simply at questioning the distinction between old and new religions itself. Rather, we think such conversation between scholarly fields holds the prospect of productive scholarly surprise and perspectival shifts, especially via the disciplinary practice of historiographical criticism.
One hundred and ten English-speaking children schooled in French were followed from kindergarten to Grade 2 (Mage: T1 = 5;6, T2 = 6;4, T3 = 6;11, T4 = 7;11). The findings provided strong support for the Home Literacy Model (Sénéchal & LeFevre, 2002) because in this sample the home language was independent of the language of instruction. The informal literacy environment at home predicted growth in English receptive vocabulary from kindergarten to Grade 1, whereas parent reports of the formal literacy environment in kindergarten predicted growth in children's English early literacy between kindergarten and Grade 1 and growth in English word reading during Grade 1. Furthermore, 76% of parents adjusted their formal literacy practices according to the reading performance of their child, in support of the presence of a responsive home literacy curriculum among middle-class parents.
We show that the tilted-grating-assisted excitation of surface plasmon polaritons on gold coated single-mode optical fibers depends strongly on the state of polarization of the core-guided light, even in fibers with cylindrical symmetry. Rotating the linear polarization of the guided light by 90° relative to the grating tilt plane is sufficient to turn the plasmon resonances on and off with more than 17 dB of extinction ratio. By monitoring the amplitude changes of selected individual cladding mode resonances we identify what we believe to be a new refractive index measurement method that is shown to be accurate to better than 5 × 10-5.
The goal of the present intervention research was to test whether guided invented spelling would
facilitate entry into reading for at-risk kindergarten children. The 56 participating children had poor
phoneme awareness, and as such, were at risk of having difficulty acquiring reading skills. Children
were randomly assigned to one of three training conditions: invented spelling, phoneme
segmentation, or storybook reading. All children participated in 16 small group sessions over eight
weeks. In addition, children in the three training conditions received letter-knowledge training and
worked on the same 40 stimulus words that were created from an array of 14 letters. The findings
were clear: on pretest, there were no differences between the three conditions on measures of early
literacy and vocabulary, but, after training, invented spelling children learned to read more words
than did the other children. As expected, the phoneme-segmentation and invented-spelling children
were better on phoneme awareness than were the storybook-reading children. Most interesting,
however, both the invented spelling and the phoneme-segmentation children performed similarly on
phoneme awareness suggesting that the differential effect on learning to read was not due to
phoneme awareness per se. As such, the findings support the view that invented spelling is an
exploratory process that involves the integration of phoneme and orthographic representations. With
guidance and developmentally appropriate feedback, invented spelling provides a milieu for children
to explore the relation between oral language and written symbols that can facilitate their entry in
The conformal coating of a 50 nm-thick layer of copper nanoparticles deposited with pulse chemical vapor deposition of a copper (I) guanidinate precursor on the cladding of a single mode optical fiber was monitored by using a tilted fiber Bragg grating (TFBG) photo-inscribed in the fiber core. The pulse-per-pulse growth of the copper nanoparticles is readily obtained from the position and amplitudes of resonances in the reflection spectrum of the grating. In particular, we confirm that the real part of the effective complex permittivity of the deposited nano-structured copper layer is an order of magnitude larger than that of a bulk copper film at an optical wavelength of 1550 nm. We further observe a transition in the growth behavior from granular to continuous film (as determined from the complex material permittivity) after approximately 20 pulses (corresponding to an effective thickness of 25 nm). Finally, despite the remaining granularity of the film, the final copper-coated optical fiber is shown to support plasmon waves suitable for sensing, even after the growth of a thin oxide layer on the copper surface.
We prove that, for every simple polygon P having k ≥ 1 reflex vertices, there exists a point q ε P such that every half-polygon that contains q contains nearly 1/2(k + 1) times the area of P. We also give a family of examples showing that this result is the best possible.
Conventional training simulators commonly use a hexapod configuration to provide motion cues. While widely used, studies have shown that hexapods are incapable of producing the range of motion required to achieve high fidelity simulation required in many applications. A novel alternative is the Atlas motion platform. This paper presents a new generalized kinematic model of the platform which can be applied to any spherical platform actuated by three omnidirectional wheels. In addition, conditions for slip-free and singularity-free motions are identified. Two illustrative examples are given for different omnidirectional wheel configurations.
A simple new technique of parallelizing methods for solving search problems which seek collisions in pseudorandom walks is presented. This technique can be adapted to a wide range of cryptanalytic problems which can be reduced to finding collisions. General constructions are given showing how to adapt the technique to finding discrete logarithms in cyclic groups, finding meaningful collisions in hash functions, and performing meet-in-the-middle attacks such as a known-plaintext attack on double encryption. The new technique greatly extends the reach of practical attacks, providing the most cost-effective means known to date for defeating: the small subgroup used in certain schemes based on discrete logarithms such as Schnorr, DSA, and elliptic curve cryptosystems; hash functions such as MD5, RIPEMD, SHA-1, MDC-2, and MDC-4; and double encryption and three-key triple encryption. The practical significance of the technique is illustrated by giving the design for three $10 million custom machines which could be built with current technology: one finds elliptic curve logarithms in GF(2155) thereby defeating a proposed elliptic curve cryptosystem in expected time 32 days, the second finds MD5 collisions in expected time 21 days, and the last recovers a double-DES key from two known plaintexts in expected time 4 years, which is four orders of magnitude faster than the conventional meet-in-the-middle attack on double-DES. Based on this attack, double-DES offers only 17 more bits of security than single-DES.
We discuss two-party mutual authentication protocols providing authenticated key exchange, focusing on those using asymmetric techniques. A simple, efficient protocol referred to as the station-to-station (STS) protocol is introduced, examined in detail, and considered in relation to existing protocols. The definition of a secure protocol is considered, and desirable characteristics of secure protocols are discussed.
A near infrared (NIR) electrochromic attenuator based on a dinuclear ruthenium complex and polycrystalline tungsten oxide was fabricated and characterized. The results show that the use of the NIR-absorbing ruthenium complex as a counter electrode material can improve the device performance. By replacing the visible electrochromic ferrocene with the NIR-absorbing ruthenium complex, the optical attenuation at 1550 nm was enhanced from 19.1 to 30.0 dB and color efficiency also increased from 29.2 to 121.2 cm2/C.
We study the feasibility of design for a layer-deposition manufacturing process called stereolithography which works by controlling a vertical laser beam which when targeted on a photocurable liquid causes the liquid to harden. In order to understand the power as well as the limitations of this manufacturing process better, we define a mathematical model of stereolithography (referred to as vertical stereolithography) and analyze the class of objects that can be constructed under the assumptions of the model. Given an object (modeled as a polygon or a polyhedron), we give algorithms that decide in O(n) time (where n is the number of vertices in the polygon or polyhedron) whether or not the object can be constructed by vertical stereolithography. If the answer is in the affirmative, the algorithm reports a description of all the orientations in which the object can be made. We also show that the objects built with vertical stereolithography are precisely those that can be made with a 3-axis NC machine. We then define a more flexible model that more accurately reflects the actual capabilities of stereolithography (referred to as variable-angle stereolithography) and again study the class of feasible objects for this model. We give an O(n)-time algorithm for polygons and O(n log n)- as well as O(n)-time algorithms for polyhedra. We show that objects formed with variable-angle stereolithography can also be constructed using another manufacturing process known as gravity casting. Furthermore, we show that the polyhedral objects formed by vertical stereolithography are closely related to polyhedral terrains which are important structures in geographic information systems (GIS) and computational geometry. In fact, an object built with variable-angle stereolithography resembles a terrain with overhangs, thus initiating the study of more realistic terrains than the standard ones considered in geographic information systems. Finally, we relate our results to the area of grasping in robotics by showing that the polygonal and polyhedral objects that can be built by vertical stereolithography can be clamped by parallel jaw grippers with any positive-sized gripper.
We provide optimal parallel solutions to several link-distance problems set in trapezoided rectilinear polygons. All our main parallel algorithms are deterministic and designed to run on the exclusive read exclusive write parallel random access machine (EREW PRAM). Let P be a trapezoided rectilinear simple polygon with n vertices. In O(log n) time using O(n/log n) processors we can optimally compute: 1. Minimum réctilinear link paths, or shortest paths in the L1 metric from any point in P to all vertices of P. 2. Minimum rectilinear link paths from any segment inside P to all vertices of P. 3. The rectilinear window (histogram) partition of P. 4. Both covering radii and vertex intervals for any diagonal of P. 5. A data structure to support rectilinear link-distance queries between any two points in P (queries can be answered optimally in O(log n) time by uniprocessor). Our solution to 5 is based on a new linear-time sequential algorithm for this problem which is also provided here. This improves on the previously best-known sequential algorithm for this problem which used O(n log n) time and space.5 We develop techniques for solving link-distance problems in parallel which are expected to find applications in the design of other parallel computational geometry algorithms. We employ these parallel techniques, for example, to compute (on a CREW PRAM) optimally the link diameter, the link center, and the central diagonal of a rectilinear polygon.
Current research depicts suburbs as becoming more heterogeneous in terms of socio-economic status. Providing a novel analysis, this paper engages with that research by operationalising suburban ways of living (homeownership, single-family dwelling occupancy and automobile use) and relating them to the geography of income across 26 Canadian metropolitan areas. We find that suburban ways of living exist in new areas and remain associated with higher incomes even as older suburbs, as places, have become more diverse. In the largest cities the relationship between income and suburban ways of living is weaker due to the growth of condominiums in downtowns that allow higher income earners to live urban lifestyles. Homeownership is overwhelmingly more important than other variables in explaining the geography of income across 26 metropolitan areas.
There is a paradoxical relationship between the density of solar housing and net household energy use. The amount of solar energy available per person decreases as density increases. At the same time, transportation energy, and to some extent, household operating energy decreases. Thus, an interesting question is posed: how does net energy use vary with housing density? This study attempts to provide insight into this question by examining three housing forms: low-density detached homes, medium-density townhouses, and high-density high-rise apartments in Toronto. The three major quantities of energy that are summed for each are building operational energy use, solar energy availability, and personal transportation energy use. Solar energy availability is determined on the basis of an effective annual collector efficiency. The results show that under the base case in which solar panels are applied to conventional homes, the high-density development uses one-third less energy than the low-density one. Improving the efficiency of the homes results in a similar trend. Only when the personal vehicle fleet or solar collectors are made to be extremely efficient does the trend reverse-the low-density development results in lower net energy.
This article interrogates the question of what it means to be a scholar-commentator in the digital age. Deploying an autoethnographic style, the essay asks about the role of power and responsibility in teaching, research, and public commentary, particularly in the context of studying and engaging in Jewish politics. The article addresses questions about the proper role of the scholar in the academy and the role of subjectivity and political commitments in structuring scholarship, pedagogy, and public engagement. It also examines how one’s view of the profession can seem to shift through the emergence of new writing outlets and new forums for public engagement. Finally, the author investigates how a scholar’s own political commitments can shift over time, how one seeks to shore up identification on social media while trying to change hearts and minds through the op-ed pages, and how community identification can serve as a buffer and motivator for particular forms of research and political action.
Ca-ATPase activity in sarcoplasmic reticulum (SR) membranes isolated from skeletal muscles of the typical hibernator, the ground squirrel Spermophilus undulatus, is about 2-fold lower than that in SR membranes of rats and rabbits and is further decreased 2-fold during hibernation. The use of carbocyanine anionic dye Stains-All has revealed that Ca-binding proteins of SR membranes, histidine-rich Ca-binding protein and sarcalumenin, in ground squirrel, rat, and rabbit SR have different electrophoretic mobility corresponding to apparent molecular masses 165, 155, and 170 kDa and 130, 145, and 160 kDa, respectively; the electrophoretic mobility of calsequestrin (63 kDa) is the same in all preparations. The content of these Ca-binding proteins in SR membranes of the ground squirrels is decreased 3–4 fold and the content of 55, 30, and 22 kDa proteins is significantly increased during hibernation.
This paper analyzes how the “particular symbolic fortunes” of Canada’s most widely recognized literary prize, the Scotiabank Giller Prize, undergo what James English calls “capital intraconversion”––how they are “culturally ‘laundered’” through their association with Frontier College, Canada’s longest-running adult literacy organization. While the Giller initially benefitted from fashioning itself as the private, industry-driven alternative to state-sponsored culture in Canada, increasing criticism of its corporate sponsorship has led, in the past decade, to a rebranding effort. This effort, I contend, seeks to benefit from two key terms––multiculturalism and literacy. Associated as the discourse of multiculturalism and the figure of the literate citizen are with the strong publics of the western, liberal-democratic nation-state, they possess a remarkable ability to accentuate the symbolic capital of Canada’s most widely recognized literary prize.
A 100-kDa protein that is a main component of the microsomal fraction from rabbit gastric mucosa is phosphorylated by cAMP-dependent protein kinase (PKA) in the presence of 0.2% Triton X-100. Microsomes from rabbit gastric mucosa possess activity of H,K-ATPase but not activity of Na,K-ATPase. Incubation of microsomes with 5 μM fluorescein 5′-isothiocyanate (FITC) results in both an inhibition of H,K-ATPase and labeling of a protein with an electrophoretic mobility corresponding to the mobility of the protein phosphorylated by PKA. The data suggest that the α-subunit of H,K-ATPase can be a potential target for PKA phosphorylation.
Social defeat in mice is a potent stressor that promotes the development of depressive- and anxiety-like behaviours, as well as variations of neuroendocrine and brain neurotransmitter activity. Although environmental enrichment may protect against some of the adverse behavioural and biological effects of social defeat, it seems that, among male group-housed mice maintained in an enriched environment (EE), aggressive behaviours may be more readily instigated, thus promoting distress and exacerbating psychopathological features. Thus, although an EE can potentially have numerous beneficial effects, these may depend on the general conditions in which mice were raised. It was observed in the current investigations that EE group-housed BALB/cByJ mice displayed increased anxiety-like behaviours compared to their counterparts maintained in a standard environment (SE). Furthermore, in response to social defeat, EE group-housed male mice exhibited decreased weight gain, exaggerated corticosterone elevations and altered hippocampal norepinephrine utilization compared to their SE counterparts. These effects were not apparent in the individually housed EE mice and, in fact, enrichment among these mice appeared to buffer against serotonin changes induced by social defeat. It is possible that some potentially beneficial effects of enrichment were precluded among group-housed mice, possibly owing to social disturbances that might occur in these conditions. In fact, even if social interaction is an essential feature of enrichment, it seems that some of the positive effects of this housing condition might be optimal when mice are housed individually, particularly with regard to buffering the effects of social defeat.
A novel technique for increasing the sensitivity of tilted fibre Bragg grating (TFBG) based refractometers is presented. The TFBG sensor was coated with chemically synthesized silver nanowires 100nm in diameter and several micrometres in length. A 3.5-fold increase in sensor sensitivity was obtained relative to the uncoated TFBG sensor. This increase is associated with the excitation of surface plasmons by orthogonally polarized fibre cladding modes at wavelengths near 1.5μm. Refractometric information is extracted from the sensor via the strong polarization dependence of the grating resonances using a Jones matrix analysis of the transmission spectrum of the fibre.
The electrical resistivity distribution at the base of La Soufrière of Guadeloupe lava dome is reconstructed by using transmission electrical resistivity data obtained by injecting an electrical current between two electrodes located on opposite sides of the volcano. Several pairs of injection electrodes are used in order to constitute a data set spanning the whole range of azimuths, and the electrical potential is measured along a cable covering an angular sector of ≈120? along the basis of the dome. The data are inverted to performa slice electrical resistivity tomography (SERT) with specific functions implemented in the EIDORS open source package dedicated to electrical impedance tomography applied to medicine and geophysics. The resulting image shows the presence of highly conductive regions separated by resistive ridges. The conductive regions correspond to unconsolidated material saturated by hydrothermal fluids. Two of them are associated with partial flank collapses and may represent large reservoirs that could have played an important role during past eruptive events. The resistive ridges may represent massive andesite and are expected to constitute hydraulic barriers.
Single-longitudinal-mode operation of Er3+-P2O5-codoped silica planar waveguide lasers which are equipped with integrated Bragg grating reflectors is demonstrated, with a polarized output of 340 μW at 1546 nm. The gratings are photo-imprinted using 193 nm light exposure through a phase mask in GeO2-free optical waveguides that have been sensitized by H2 loading.
The core refractive index of Corning SMF-28 optical fibre exposed to ArF laser pulses increases with the square of the fluence per pulse. Bragg gratings with a refractive index modulation amplitude higher than 10
-3 have been obtained. This is an order of magnitude improvement over previously reported values for this type of fibre in the absence of treatment to enhance the photosensitivity.
When hydrogen loading is used to enhance the photosensitivity of silica-based optical waveguides and fibres, the presence of molecular hydrogen dissolved in the glass matrix changes the effective index of propagation of guided optical modes by as much as 0.05%. Real-time monitoring of the reflectivity spectrum of Bragg gratings written in such conditions shows that the centre wavelength follows the changes in hydrogen concentration due to diffusion and reaction with glass defects.
An apodized chirped in-fibre Bragg grating that has a linear dispersion characteristic is reported. The frequency components of an optical pulse (centre wavelength 1551 nm; 10 GHz bandwidth) incident on the grating are reflected with a relative delay that varies linearly from 0 to 130 ps across the spectral width of the pulse. The dispersion compensator is used to correct for the dispersion in a 100 km link (nondispersion shifted fibre) operating at a 10 Gbit/s transmission rate and a wavelength of 1551 nm.
An apodized in-fibre Bragg grating reflector is fabricated using the phase mask photoimprinting technique. The reflector has a centre wavelength of 1550 nm, a bandwidth of 0.22 nm and a peak reflectivity of 90%. At 0.4 nm (50 GHz) from the centre wavelength the reflectivity is 40 dB lower than the peak reflectivity; this is an improvement of more than 20 dB over an unapodized Bragg grating reflector with similar bandwidth and peak reflectivity.
Random Forests variable importance measures are often used to rank variables by their relevance to a classification problem and subsequently reduce the number of model inputs in high-dimensional data sets, thus increasing computational efficiency. However, as a result of the way that training data and predictor variables are randomly selected for use in constructing each tree and splitting each node, it is also well known that if too few trees are generated, variable importance rankings tend to differ between model runs. In this letter, we characterize the effect of the number of trees (ntree) and class separability on the stability of variable importance rankings and develop a systematic approach to define the number of model runs and/or trees required to achieve stability in variable importance measures. Results demonstrate that both a large ntree for a single model run, or averaged values across multiple model runs with fewer trees, are sufficient for achieving stable mean importance values. While the latter is far more computationally efficient, both the methods tend to lead to the same ranking of variables. Moreover, the optimal number of model runs differs depending on the separability of classes. Recommendations are made to users regarding how to determine the number of model runs and/or trees that are required to achieve stable variable importance rankings.
The rise of game development and game studies on university campuses prompts academic libraries to consider how to support teaching and research in this area. This article examines current issues and challenges in the development of game collections at academic libraries. The gaming ecosystem has become more complex and libraries may need to move beyond collections largely based on console video games. This article will advance the discussion by considering emerging issues to support access to the full range of games. The article will use examples from Carleton University Library, Ottawa, which has been developing a game collection since 2008.
This article describes the progress made toward implementing Resource Description and Access (RDA) in libraries across Canada, as of Fall 2013. Differences in the training experiences in the English-speaking cataloging communities and French-speaking cataloging communities are discussed. Preliminary results of a survey of implementation in English-Canadian libraries are included as well as a summary of the support provided for French-Canadian libraries. Data analysis includes an examination of the rate of adoption in Canada by region and by sector. Challenges in RDA training delivery in a Canadian context are identified, as well as opportunities for improvement and expansion of RDA training in the future.
The design and analysis of community-scale energy systems and incentives is a non-trivial task. The challenge of such undertakings is the well-documented uncertainty of building occupant behaviours. This is especially true in the residential sector, where occupants are given more freedom of activity compared to work environments. Further complicating matters is the dearth of available measured data. Building performance simulation tools are one approach to community energy analysis, however such tools often lack realistic models for occupant-driven demands, such as appliance and lighting (AL) loads. For community-scale analysis, such AL models must also be able to capture the temporal and inter-dwelling variation to achieve realistic estimates of aggregate electrical demand. This work adapts the existing Centre for Renewable Energy Systems Technology (CREST) residential energy model to simulate Canadian residential AL demands. The focus of the analysis is to determine if the daily, seasonal, and inter-dwelling variation of AL demands estimated by the CREST model is realistic. An in-sample validation is conducted on the model using 22 high-resolution measured AL demand profiles from dwellings located in Ottawa, Canada. The adapted CREST model is shown to broadly capture the variation of AL demand variations observed in the measured data, however seasonal variation in daily AL demand behaviour was found to be under-estimated by the model. The average and variance of daily load factors was found to be similar between measured and modelled. The model was found to under-predict the daily coincidence factors of aggregated demands, although the variance of coincident factors was shown to be similar between measured and modelled. A stochastic baseload input developed for this work was found to improve estimates of the magnitude and variation of both baseload and peak demands.
It has been observed in the literature that as the cardinality of the prescribed discrete input-output data set increases, the corresponding four-bar linkages that minimise the Euclidean norm of the design and structural errors tend to converge to the same linkage. The important implication is that minimising the Euclidean norm, or any p-norm, of the structural error, which leads to a nonlinear least-squares problem requiring iterative solutions, can be accomplished implicitly by minimising that of the design error, which leads to a linear least-squares problem that can be solved directly. Apropos, the goal of this paper is to take the first step towards proving that as the cardinality of the data set tends towards infinity the observation is indeed true. In this paper we will integrate the synthesis equations in the range between minimum and maximum input values, thereby reposing the discrete approximate synthesis problem as a continuous one. Moreover, we will prove that a lower bound of the Euclidean norm, and indeed of any p-norm, of the design error for planar RRRR function-generating linkages exists and is attained with continuous approximate synthesis.
Building Performance Simulation (BPS) is a powerful tool to estimate and reduce building energy consumption at the design stage. However, the true potential of BPS remains unrealized if trial and error simulation methods are practiced to identify combinations of parameters to reduce energy use of design alternatives. Optimization algorithms coupled with BPS is a process-orientated tool which identifies optimal building configurations using conflicting performance indicators. However, the application of optimization approaches to building design is not common practice due to time and computation requirements. This paper proposes a hybrid evolutionary algorithm which uses information gained during previous simulations to expedite and improve algorithm convergence using targeted deterministic searches. This technique is applied to a net-zero energy home case study to optimize trade-offs in passive solar gains and active solar generation using a cost constraint.
Oral narrative skills are assumed to develop through parent-child interactive routines. One such
routine is shared reading. A causal link between shared reading and narrative knowledge,
however, has not been clearly established. The present research tested whether an 8-week
shared-reading intervention enhanced the fictional narrative skills of children entering formal
education. Dialogic reading, a shared reading activity that involves elaborative questioning
techniques, was used to engage children in oral interaction during reading and to emphasize
elements of story knowledge. Forty English-speaking five- and six-year-olds were assigned to
either the dialogic-reading or an alternative-treatment group. ANCOVA results found that the
dialogic-reading children’s post-test narratives were significantly better on structure and context
measures than those for the alternative-treatment children, but results differed for produced or
retold narratives. The dialogic-reading children also showed expressive vocabulary gains.
Overall, this study concretely determined that aspects of fictional narrative construction
knowledge can be learned from interactive book reading.
Techno-economic impact of retrofitting houses in the Canadian housing stock with PV and BIPV/T systems is evaluated using the Canadian Hybrid End-use Energy and Emission Model. Houses with south, south-east and south-west facing roofs are considered eligible for the retrofit since solar irradiation is maximum on south facing surfaces in the northern hemisphere. The PV system is used to produce electricity and supply the electrical demand of the house, with the excess electricity sold to the grid in a net-metering arrangement. The BIPV/T system produces electricity as well as thermal energy to supply the electrical as well as the thermal demands for space and domestic hot water heating. The PV system consists of PV panels installed on the available roof surface while the BIPV/T system adds a heat pump, thermal storage tank, auxiliary heater, domestic hot water heating equipment and hydronic heat delivery system, and replaces the existing heating system in eligible houses. The study predicts the energy savings, GHG emission reductions and tolerable capital costs for regions across Canada. Results indicate that the PV system retrofit yields 3% energy savings and 5% GHG emission reduction, while the BIPV/T system yields 18% energy savings and 17% GHG emission reduction in the Canadian housing stock. While the annual electricity use slightly increases, the fossil fuel use of the eligible houses substantially decreases due to BIPV/T system retrofit.
Fuel cells with nominal outputs of approximately 1kW AC are emerging as a prime-mover of a micro-cogeneration system potentially well-suited to compete, on an energy basis, with conventional methods for satisfying occupant electrical and thermal demands in a residential application. As the energy benefits of these systems can be incremental when compared to efficient conventional methods, it is especially important to consider the uncertainties of the models on which simulation results are based. However, researchers have yet to take this aspect into account.This article makes a contribution by demonstrating how these model uncertainties may be propagated to the simulation results of a micro-cogeneration system for comparison to a reference scenario using a case study. This case study compares the energy performance of a fuel-cell based micro-cogeneration system serving only domestic hot water demands to an efficient reference scenario where the conventional methods for providing electrical and thermal demands are considered to be a central gas-fired combined-cycle plant and a condensing tankless water heater respectively. The simulation results demonstrated that if model uncertainties were ignored, it would have been possible to demonstrate that the considered micro-cogeneration system was more efficient than the reference scenario for average consumption levels of domestic hot water. However, when model uncertainties were considered, the efficiency of the considered micro-cogeneration system could not reliably exceed that of the reference scenario by serving the domestic hot water needs of a single-family home.
An improved understanding of the consumption patterns, end-uses, and temporal variations of electrical loads in houses is warranted because a significant fraction of a society's total electricity consumption occurs within residential buildings. In general, there is a lack of high-temporal-resolution data describing occupant electrical consumption that are available to researchers in this field. To address this, new measurements were performed and combined with data emanating from an earlier study to provide a database of annual measurements for 23 houses at a 1-min resolution that characterizes whole-house, non-HVAC, air conditioner, and furnace fan electrical draws, as well as the draw patterns of some major appliances. All houses were located in Ottawa, Canada. The non-HVAC measurements of this 23-house sample were shown to be in agreement with published estimates for the housing stock. The furnace fan was found to be the most significant end-use. These high-temporal-resolution data of electrical demands in houses can be used by researchers to increase the fidelity of building performance simulation analyses of different micro-generation technologies in residential buildings.
This study was conducted to assess the techno-economic feasibility of converting the Canadian housing stock (CHS) into net/near zero energy buildings by introducing and integrating high efficient and renewable/alternative energy technologies in new construction and existing houses. Performance assessment of energy retrofit and renewable/alternative energy technologies in existing houses in regional and national scale is necessary to devise feasible strategies and incentive measures. The Canadian Hybrid Residential End-Use Energy and GHG Emissions model (CHREM) that utilizes a bottom-up modeling approach is used to investigate the techno-economic feasibility of air to water heat pump retrofit in the Canadian housing stock. The proposed energy retrofit includes an air to water heat pump, auxiliary boiler, thermal storage tank, hydronic heat delivery and domestic hot water (DHW) heating. Energy savings, GHG emission changes and economic feasibility of the air source heat pump retrofit are considered in this study. Results show that there is a potential to reduce 36% of energy consumption and 23% of GHG emissions of the CHS if all eligible houses undertake the retrofit. Economic analysis indicates that the feasibility of air to water heat pump systems is strongly affected by the current status of primary energy use for electricity generation and space and DHW heating as well as energy prices and economic conditions. Legislation, economic incentives and education for homeowners are necessary to enhance the penetration level of air to water heat pump retrofits in the CHS.
Buildings play a significant role in climate change mitigation. In North America, energy used to construct and operate buildings accounts for some 40% of total energy use, largely originating from fossil fuels. The strategic reduction of these energy demands requires knowledge of potential upgrades prior to a building's construction. Furthermore, renewable energy generation integrated into buildings façades and district systems can improve the resiliency of community infrastructure. However, loads that are non-coincidental with on-site generation can cause load balancing issues. This imbalance is typically due to solar resources peaking at noon, whereas building loads typically peak in the morning and late afternoon or evenings. Ideally, the combination of on-site generation and localized storage could remedy such load balancing issues while reducing the need for fossil fuels. In response to these issues, this paper contributes a methodology that co-optimizes building designs and district technologies as an integrated community energy system. A distributed evolutionary algorithm is proposed that can navigate over 10154 potential community permutations. This is the first time in literature that a methodology demonstrates the co-optimization of buildings and district energy systems to reduce energy use in buildings and balance loads at this scale. The proposed solution is reproducible and scalable for future community masterplanning studies.
The techno-economic feasibility of retrofitting existing Canadian houses with solar assisted heat pump (SAHP) is investigated. The SAHP architecture is adopted from previous studies conducted for the Canadian climate. The system utilizes two thermal storage tanks to store excess solar energy for use later in the day. The control strategy is defined in order to prioritise the use of solar energy for space and domestic hot water heating purposes. Due to economic and technical constraints a series of eligibility criteria are introduced for a house to qualify for the retrofit. A model was built in ESP-r and the retrofit was introduced into all eligible houses in the Canadian Hybrid Residential End-Use Energy and GHG Emissions model. Simulations were conducted for an entire year to estimate the annual energy savings, and GHG emission reductions. Results show that the SAHP system performance is strongly affected by climatic conditions, auxiliary energy sources and fuel mixture for electricity generation. Energy consumption and GHG emission of the Canadian housing stock can be reduced by about 20% if all eligible houses receive the SAHP system retrofit. Economic analysis indicates that the incentive measures will likely be necessary to promote the SAHP system in the Canadian residential market.
I examine the relation between sensation and discursive thought (dianoia) in Plato, Plotinus, and Proclus. In Theaetetus, a soul whose highest faculty was sensation would have no unified experience of the sensible world, lacking universal ideas to give order to the sensible flux. It is implied that such universals are grasped by the soul's thinking. In Plotinus the soul is not passive when it senses the world, but as the logos of all things it thinks the world through its own forms. Proclus argues against the derivation of universal logoi from the senses, which alone can't make the sensible world comprehensible. At most they give a record of the original sense-impression in its particularity. The soul's own projected logoi give the sensible world stability. For Proclus, bare sensation does not depend on thought, but a unified experience of the sense-world depends on its paradigmatic logoi in our souls.
A variable diffraction efficiency phase mask is produced by focused ion beam, implanting a grating pattern into a fused SiO
2 substrate with a 100-nm-diam, 200keV Si beam. The substrate is prepared by cleaning and coating with a 20-nm-thick film of Al to dissipate the ion charge. The pattern consists of 930 lines, each 80μm long, at a pitch of 1.075μm, to obtain a 1-mm-long grating. The substrate is wet etched in a 1M% HF solution for about 45min to produce a phase mask with the desired diffraction efficiency. This phase mask is used to photoimprint Bragg gratings into standard hydrogenated single-mode telecommunication fibers using 193nm light from an ArF laser.
Frost cracking, the breakdown of rock by freezing, is one of the most important mechanical weathering processes acting on Earth's surface. Insights on the mechanisms driving frost cracking stem mainly from laboratory and theoretical studies. Transferring insights from such studies to natural conditions, involving jointed bedrock and heterogeneous thermal and hydrological properties, is a major challenge. We address this problem with simultaneous in situ measurements of acoustic emissions, used as proxy of rock damage, and rock temperature/moisture content. The 1 year data set acquired in an Alpine rock wall shows that (1) liquid water content has an important impact on freezing-induced rock damage, (2) sustained freezing can yield much stronger damage than repeated freeze-thaw cycling, and (3) that frost cracking occurs over the full range of temperatures measured extending from 0 down to -15°C. These new measurements yield a slightly different picture than previous field studies where ice segregation appears to play an important role. Key PointsRock liquid water content has an important impact on the freezing-induced damageSustained freezing can yield stronger damage than repeated freeze-thaw cyclingFrost cracking occurs on a wide range of temperatures extending from 0 to -15C
The aeronautics industry is looking for ice protection systems consuming less energy. Electromechanical and especially piezoelectric solutions are a promising area of research for reducing average consumptions. This article provides an analytical model
of a simple structure to assess the power and voltage required to obtain the delamination of the accumulated layer of ice at the support/ice interface. This model also allows analyzing the impact of the resonance frequencies used for supplying piezoelectric actuators on the tensile stress into PZT materials. Finally, this article assesses the effect of different ice
- phobic coatings combined with piezoelectric ice protection systems.
Experimental measurements of ice adhesion for different ice - phobic coatings allow evaluating the shear stress at which ice is detached from the surface. These results are then used to estimate - thanks to the proposed analytical model
- the additional gain of power that would be provided by the use of such coatings.
Phosphate glass samples doped with silver ions through a Na+-Ag+ ion-exchange process were treated in a hydrogen atmosphere at temperatures near 430 °C for durations ranging from 4 to 5 h. Such treatment causes metallic silver precipitation at the surface as well as nanoclustering of silver atoms under the surface under conditions very similar to those used for silicate glasses. The presence of silver clusters resulted in a characteristic coloring of the glass and was verified by the observation of a plasmon resonance peak near 410-420 nm in the absorption spectra. Applying a DC voltage between 1.4 and 2 kV at temperatures between 120 and 130 °C led to dissolution of the clusters in the area under the positive electrode, thereby bleaching the glass color. The use of a patterned doped-silicon electrode further led to the formation of a 300 nm thick surface relief on the glass surface and of a volume complex permittivity grating extending at least 4 μm under the surface. Such volume complex refractive index gratings may find applications in passive or active (laser) photonic devices in rare-earth doped phosphate glasses, where conventional bulk grating formation techniques have limited applicability.
Germanium ions have been implanted in fused silica using ion beams having energies of 3 and 5 MeV and doses ranging from 1×1012 to 5×1014 ions/cm2. For wavelengths shorter than 400 nm, the optical absorption increases strongly with two absorption bands appearing at 244 and 212 nm. The ion-induced optical absorption can be bleached almost completely by irradiation with 249 nm excimer laser light. Ion implantation also increases the refractive index of silica near the substrate surface. At 632.8 nm a refractive index increase of more than 10-2 has been measured. This decreases by 4×10-3 upon bleaching with 249 nm light.
A fiber twist sensor based on the surface plasmon resonance (SPR) effect of an Au-coated tilted fiber Bragg grating (TFBG) is proposed. The SPR response to the twist effect on an Au-coated TFBG (immersing in distilled water) is studied theoretically and experimentally. The results show that the transmission power around the wavelength of SPR changes with the twist angle. For the twist ranging from 0° to 180° in clockwise or anti-clockwise directions, the proposed sensor shows sensitivities of 0.037 dBm/° (S-polarized) and 0.039 dBm/° (P-polarized), which are almost 7.5 times higher than that of the current similar existing twist sensor.
We have studied optical changes induced by ArF (6.4 eV/193 nm) excimer laser light illumination of high purity SiO2 implanted with Si2+ (5 MeV) at a fluence of 1015 ions/cm2. Optical absorption was measured from 3 eV (400 nm) to 8 eV (155 nm) and showed evidence of several well-defined absorption bands. A correlation in the bleaching behavior appears to exist between the so-called D band (located at 7.15 eV) and the well-known B2α band which is attributed to oxygen vacancies. Changes in the refractive index as a function of ArF illumination were measured and found to be in good quantitative agreement with a Kramers-Kronig analysis of the optical absorption data.
A two-step double ion-exchange process is employed to produce dual-core waveguides in glass. First, potassium ion exchange is carried out at 400°C. Then, silver ion exchange is performed at 300°C. The fabricated waveguides have low losses, large single-mode regions, and more symmetrical profiles than single ion-exchanged waveguides. Etched gratings are also made in dual-core waveguides. Very high efficiencies are demonstrated in these waveguides.
Each year the Canadian government allocates a significant amount of money for science and technology. A major portion of this allocation goes for R& D. In order to enjoy adequate return, technologies that are developed in Canadian federal labs need to be transferred to the public effectively. There are critical factors in technology transfer which play a key role in determining the effectiveness of this transfer process. This study examines the technical, organizational, and people factors which can enhance technology transfer from government laboratories.
Every year, for over three decades, Carleton University in Ottawa, Ontario has participated with other local educational institutions in providing a week-long instruction program that introduces young students to higher education. Highly motivated participants in grades 8 – 11 and numbering over 3,000 attend from several school boards in both eastern Ontario and western Quebec. The Enriched Mini Course Program has become an important recruitment tool for each institution, and at Carleton University, over 50 enriched mini courses are offered including one recent addition by the MacOdrum library staff.
In this article, the author recounts how leading an enriched mini course for millennials in the university library's new Discovery Centre is an innovative initiative that demonstrates the significance of the academic library in the local community, and how staff collaboration helps to develop team building and positive vibes with the millennials.
One reason teams are seen to be a high-performance work practice (HPWP) is that the diversity of team member knowledge, skills and abilities, known as cognitive resource diversity supposedly brings new perspectives, information, ideas and resources to the solution of problems and the exploration and exploitation of opportunities. However, to date the performance of heterogeneous teams has been disappointing with the most common finding being increased conflict. Based on social identity and social exchange theories and building onto Mayer, Davis & Schoorman's (1995) classic integrative model of trust, this paper proposes that trust is a critical mediator in the relationship between cognitive resource diversity and within-team knowledge sharing.
Entrepreneurship is a recognized concept both for research and practice. It is possible to find university courses, research published in specialized journals, associations dedicated to entrepreneurship promotion and governmental support. In a regional economic development context, a special form of entrepreneurship could achieve other objectives. Social entrepreneurship is an emergent concept earning more popularity than ever around the planet. However the concept is not well known. The objective of the paper is to present an overview of the social entrepreneurship concept.
Research emphasizing evolutionary and resource-based perspectives of the firm highlights the importance of core capabilities as sources of superior performance, and views capabilities in computer-based IT systems as instrumental in leading to strategic advantage. However, the asymmetrical results from such systems present a somewhat confusing picture as to the key issues that managers should be addressing. We present an approach to IS capability development that applies a combined evolutionary and resource-based perspective. We propose that IS capability is determined along three strategic dimensions and will result from effective and sustained efforts in three complementary areas that are discussed in this paper. We use three case studies to illustrate the use of the proposed IS capability framework in analyzing information systems in organizations.
The article scrutinizes the complex entanglement of cyberurban spaces in the making and development of contemporary social movement by analyzing its imaginaries, practices, and trajectories.
This issue of New Geographies, “Geographies of Information” (edited by Taraneh Meskhani & Ali Fard), presents a new set of frameworks that refrain from generalizations to highlight the many facets of the socio-technical constructions, processes, and practices that form the spaces of information and communication. In addition to Lim, contributors of the issue include prominent thinkers and scholars in various related disciplines such as Rob Kitchin (critical data), Stephen Graham (urbanism) and Malcolm McCullough (architecture/urban computing).
This paper examines the role of affect in marketing positioning strategy and individual positioning judgements. We examine affect in both the marketing and positioning literatures and argue that vestiges of the dual mind perspective are alive and well in positioning. Viewing 'thinking' and 'feeling' as entirely separate (as in utilitarian vs. hedonic product distinctions) runs counter to advances in neuroscience and devalues individual differences and brain functioning. As a result of our own coding of positioning dimensions, we advocate for a greater understanding of the complex interplay between affect and cognition in positioning strategy and judgements.
A review of five major journals in the Management Information Systems (MIS) field reveals that the majority of research articles engaging with Critical Theory, from the period 1990 to 2001, are of a conceptual nature, focusing primarily on systems development. Two reasons are suggested for the comparatively low level of engagement with Critical Theory in empirical research efforts: lack of a critical theory method and reluctance to engage with the theory's emancipatory commitments. A critical theory method that encompasses both quantitative and qualitative data collection methods is advanced. In addition, a more practiceoriented way of thinking about emancipation is proposed.
The paper identifies the characteristics of firm activities that constitute its technology scanning dynamic capability, which enables the firm to translate information about customer needs into information about tangible ways to introduce new products and services to satisfy those needs. The ability to find a specific actionable way to address customer needs is proposed to be measured by a latent construct called technology scanning. Using the literature on marketing, innovation management, knowledge management, new product development, and economics, five dimensions are identified for a technology scanning scale. A strong presence of 'technology scanning' ensures that the firm's resources are targeted to find the solution of the problems that matters most, the ones that were identified as a consequence of high level of market orientation of the firm. This work would shed some light on how managers might solve the problems and needs of the customers identified through market orientation practices. When market orientation guides technology scanning activities, the outcomes are more desirable to the firm.
In this study we will discuss the historical changes in the work and life relationship which resulted in development of new theories. After an introduction to work-life relationships, different theories of work and life are presented in the second section of this paper. These theories are categories intro three generations based on their characteristics in the historical evolution of work-life studies. In the third section measures of work and life spillovers are described. In section four, critiques of the current methodologies which is being used in the work and life studies are presented. Discussion section which is presented in following section includes some arguments regarding the ways to select the most appropriate theories for work-life studies. Also in this section some recommendations are presented for enhancing the commonly used methodologies of the research on work and life relationships. Finally, in the last section, some recommendations for future studies are presented.
This study uses theories of motivation to analyze how performance changes over the life of a contract. Utilizing performance data for professional basketball players in the NBA for three seasons, the results show that performance does change over the life of a contract. Factors affecting how much control a player has over his performance are found to be important in how the players' performance changes as the contract completion nears.
This study uses an exploratory qualitative design to examine the lived experience of one group of service users on community treatment orders (CTOs). The study was designed and completed by four graduate students at Carleton University School of Social Work.
Despite the unique features of CTO legislation in Ontario, many findings from this study are remarkably similar to findings of research conducted in other jurisdictions. What is unique in our findings is the lack of focus on the actual conditions and provision of the CTO. The issue for our participants was less about the CTO itself, and more about the labels, control and discrimination associated with severe mental illness.
Cette étude utilise un concept qualitatif et exploratoire pour examiner les expériences vécues d’un groupe qui utilise les ordonnances de traitement en milieu communautaire (OTMC). Cette étude a été designée et complétée par 4 étudiants de l’école de service social de l’université Carleton.
Malgré les nombreux aspects uniques de la loi gérant les OTMC de l’Ontario, plusieurs résultats de cette étude sont remarquablement similaires aux résultats découverts dans de différentes juridictions. L’élément unique de cette recherche est le manque de focus sur les conditions véritables et les provisions des OTMC. La problématique encourue par les participants n’était pas au sujet des OTMC en soi, mais plus tôt au sujet de l’étiquetage, du contrôle, et de la discrimination associé aux troubles de santé mentale sévères.
Managers are often measured against an ideal that is treated as a tangible object which is stable across generations. It is the contention of this paper that the ideal manager is, in fact, a social construct that is a product of the political and social context within which it exists. Different periods in time create unique typifications of the construct, and the ideal manager is not independent of its environment. The socially constructed nature of the ideal manager will be illustrated through the analysis of the construct at one specific point in time, the internal Cold War in the years following the Second World War and ending in 1960. While widely studied in most disciplines, the Cold War has been largely ignored in the management literature, and therefore provides us with a unique perspective from which to assess the impact of context on the standard to which managers are held.
This paper reviews major differences between the accounting regulatory systems in Canada and the United States. In the U.S., the Sarbanes-Oxley Act of 2002 governs responsibilities of management, auditors, and Boards of Directors related to internal control over financial reporting. In Canada, a series of Multilateral Instruments under provincial jurisdiction serves similar objectives. As compared to the U.S., the Canadian system is more decentralized and principles-based allowing a greater degree of responsibility to the accounting profession for standard setting and oversight. The Canadian approach has resulted in weaker regulation, slower implementation, and greater influence by the accounting profession. These findings imply that accounting regulations should be tailored to fit the political and institutional structures of the adopting country.
This paper presents selected preliminary results from a study of B2B e-commerce
adoption by Canadian manufacturing firms. The goal of the broad research project
IS to describe the behaviour of Canadian manufacturers with respect to adoption
of B2B technologies and to identify factors which distinguish adopters from non-adopters
of B2B. The study focuses on the organizational characteristics of
adopters of B2B e-commerce technologies and attempts to outline the features
which differentiate them from non-adopters. Preliminary analysis shows the
existence of three distinct B2B adopter types: non-adopters, partial-adopters and
full-adopters. Leadership related variables appear to be the most important
determinants of adoption.
Implementation of quality management practice in E-Commerce (EC) is a relatively new challenging area to researchers and managers. Proliferation of EC provides an opportunity to quality management gurus to reshape quality dimensions suitable for real sustainability, expansion, and success of EC. Based on the underpinning principles of Total Quality Management (TQM) and quality management practice this paper focuses on the quality dimensions required for launching a successful EC as the competitive edge in gaining market leadership. This article postulates a model to integrate quality management in EC.
Surveys of Australian consumers before and after French nuclear testing in the Pacific show clear evidence of negative responses of consumers to the 1995 testing. Although evaluations of French products did not decline, evaluations of France and the French did. However, by 2005 ratings of French products and France had more than recovered. A model of effects among country and product belief sets is proposed and tested. The model is strongly supported and helpful in understanding the process of image recover.
This paper applies attitude theory to assess the influence of beliefs and evaluations of Nepal with desired linkages and travel intentions. The main contribution is to connect TDI and PCI research by testing a general country image model in a tourism context. Attitude theory acts as the connection between the two fields.