bluuebunny/crossref_metadata_2025 huggingface dataset:
Usages langagiers et jeunes générations : regards de périphérie
Authors: Singy Pascal , Bourquin Céline
Published: September 2012

Un examen du rapport entre usages langagiers et jeunes générations opéré au travers d’une catégorie « jeune » comprise comme une et indivise apparaît en contradiction avec ce constat voulant que les langues se trouvent soumises aux pressions d’un contexte socio-historique qui confère à leurs locuteurs une pluralité d’identités sociales. Celles-ci apparaissent comme autant de sources de variation tant au plan de l’activité langagière qu’à celui des représentations y attenantes. Les ensembles ritualisés de pratiques symboliques propres aux jeunes locuteurs ne sauraient échapper à la règle et tout indique que l’investissement particulier au plan du linguistique, tenu pour être caractéristique des adolescents, peut être de nature, d’intensité et d’activation fort variables suivant le profil de ces derniers compris en termes d’identités sociales. Cet article vise à rendre compte de certains résultats d’une étude qualitative menée auprès de jeunes locuteurs de Suisse romande. Ces résultats tendent à montrer que l’identité sociale que constitue le fait d’être un jeune locuteur résidant en zone francophone de périphérie, et non en zone centrale, conditionne de manière significative – et dans un sens déterminé – le rapport que l’on peut avoir à ces ensembles de pratiques communément dénommés, dans l’espace du français, « parlers jeunes ».
L’objet livre à l’aube de l’époque moderne
Authors: Boutcher Warren
Published: September 2012

Cet article s’empare de l’objet livre afin d’envisager ce à quoi pourrait ressembler une anthropologie historique des artéfacts littéraires. Pour cela, nous appliquons la théorie du « réseau de l’art » développée par Alfred Gell à l’analyse des actions et des relations sociales médiatisées par les livres. Le point clé de cette analyse est la reconstitution des calculs d’abductions utilisés par les acteurs et les participants-observateurs dans diverses cultures et périodes. Deux exemples de la fin de la Renaissance sont analysés en détail : la description par Michel de Montaigne des fortunes de la Theologia Naturalis de Raymond Sebond, et la description par Francis Bacon des destinées du Basilikon Doron du roi Jacques VI d’Écosse et Ier d’Angleterre. Ces exemples montrent que les livres peuvent matérialiser toutes sortes d’actions, depuis la prévention des maladies mentales jusqu’à l’entrée d’un monarque en son royaume.
Dynamic Load Modeling Based on Extreme Learning Machine
Authors: Liu Zhong Hui , Wang Zhen Shu , Su Mei Hua
Published: September 2012

The dynamic load characteristics have significant impact on the power flow, transient stability computation, voltage stability calculation of the power system, and so on. Noticing that traditional mechanism loads model has difficulty in precisely describing the dynamic characteristics of synthetic load, this paper presents a non-mechanism dynamic load model based on Extreme Learning Machine (ELM). The Power Fault Recorder and Measurement System (PFRMS) is used to obtain data for load modeling. Take voltage and real/reactive power with different time delay as inputs, and take real/reactive power as output, train the ELM using the samples formed by fault data, the real power model and reactive power model are established respectively. The number of hidden layer nodes which has impact on the ELM model is also discussed. Dynamic simulation experiment is conducted at power system dynamic simulation laboratory. The simulation result shows that the ELM load model is simple and flexible, its parameters are easy to be identified. The ELM load model can describe the dynamic load characteristics accurately.
The Research and Design for IPSec Protocol Based on Embedded Linux OS over IPv6
Authors: Chen Xiao Dan , Yue Qiang , Su Li Min
Published: September 2012

The paper analyzes the principle and key technique of IPSec protocol, researches the security policy and processing flow of IPSec, presents the design ideal and implementation scheme of IPSec based on embedded Linux Operation System. The realization of IPSec mainly consists of five modules. In addition, every module function is discussed in detail.
Response Characteristic of Soil Moisture and Salt to Salt Isolated Layer in Seashore Saline Soil
Authors: Yin Xiao Lin , Ding Guo Dong , Gao Yuan Yuan
Published: September 2012

Research of soil salt and water movement rules is the premise and foundation of the construction of vegetation in seashore saline-alkali land. 20cm slag was set as salt isolated layer in the bottom of plant pit to study the rule of seasonal variation of soil profile salt and water. The result indicates that:(1) salt isolated layer not only can reduce the changes of soil moisture content at different depth significantly, and make it to be stable, but also has obvious effect to maintain the consistency of soil moisture, this is beneficial to the survival and growth of saline-alkali plants (2) salt isolated layer makes the changes of electrical conductivity relative alleviation at different soil depths, slowly increase, lesser range, even it inhibit the salt movement in dry season. This paper shows that the setting of salt isolated layer can adjust water and salt in saline-alkali soil, improve the survival rate and growth of saline-alkali plants.
Estimation of Forest Carbon Storage Based on Airborne LiDAR Data
Authors: Liu Chong , Shao Zhen Feng
Published: September 2012

The objective of this study was to estimate the carbon storage of forest areas by using airborne light detection and ranging (LiDAR) data. Digital canopy height model (CHM) which generated from point cloud data was combined with accurate geo-referenced true color orthophoto image to produce parameter information of trees (height, canopy diameter, DBH data) in test area by marker controlled watershed segmentation algorithm. The total carbon storage of experimental site could be calculated by adopting binary tree volume table and semi-empirical inversion means. This study suggested that the carbon storage of forest areas can be effectively estimated by using LiDAR data, which will play an important role in forest data updating and process of forget sustainable development.
Based on GIS and MATLAB Technology Forecast the Dynamic Variation of the Groundwater in Minqin Oasis
Authors: Fan Dong Li , Cui Xi Min , Yuan De Bao , Qiu Ya Hui , Wang Kun , Jia Xi Xi
Published: September 2012

This paper carried out interpolation processing to the groundwater hydrology data of Minqin oasis from 2000 to 2009, via ArcGIS software. Analyzed the result, it was concluded that the distribution rule about spatio-temporal distribution and change of the groundwater depth and mineralization. Using MATLAB the program language, the grey forecasting model was well fitted compared to the time series forecasting model. For the next five years, the groundwater depth and mineralization changes were forecasted, and the author put forward some concrete proposals.
A Scheme on PN Code Tracking of DS/FH Signals for Telemetry Tracking, and Commanding (TT&C)
Authors: Chen Shao Hua , Li Jia Qi , Wang Ju
Published: September 2012

The impact of Doppler frequency hopping on code tracking performance is simulated. A design on pseudo-noise (PN) Code Tracking Loop aided by the carrier tracking loop according to the carrier frequency hoping pattern is proposed in this paper. This scheme can be applied in the Telemetry, Tracking, and Commanding system which uses Direct Sequence/Frequency Hopping Spread Spectrum (DS/FH) hybrid spread spectrum technology. Simulations of the code tracking loop under different carrier to noise ratios are compared based on this scheme. The results show this method on PN code tracking of DS/FH signals is valid.
Extraction of Polyphase Modulation Parameters Using Cyclic Spectral Analysis
Authors: Zhang Xin , Liu Feng , Zheng Peng , Xu Hui Fa
Published: September 2012

This paper presents an efficient algorithm to extract the polyphase modulation parameters from intercepted signals. The algorithm is essentially based on the cyclic spectral analysis method. A calculation of parameters extraction relative error as a function of different signal patterns reveals the performance of the algorithm, which is validated via simulation examples.
Effective Fine Timing Synchronization Based on Pilot Resolution and MDS Estimation for a Coherent DRM Receiver
Authors: Xue Bin , Tian Tian , Li Lin Tao , Wang Jing
Published: September 2012

Receiver timing synchronization is one of the most important tasks in DRM system. An effective method of fine timing for DRM is presented. Firstly, it is shown that characteristics of DRM pilot pattern from consecutive OFDM symbols can increase the resolution in time and frequency domain to obtain exact channel impulse response (CIR). Secondly, we take Maximum Difference Scaling (MDS) which arrived the best fine timing point during the input samples in DRM receiver to get the concentration of the CIR. This approach has no path alias and is always able to synchronize to the first arriving path even though it is not the strongest path. In the actual coherent DRM System, this method proves to be effective and reliable.
Rate-Compatible Punctured Ring Convolutional Coded Continuous Phase Modulation
Authors: Zhang Lei , Tong Man Ping , Wang Hong Bo
Published: September 2012

In this paper, continuous phase modulation (CPM) with rate-compatible punctured ring convolutional codes is investigated. Some typical schemes with maximum normalized minimum squared euclidean distance (NMSED) are searched and given. The performance of bit error rate for rate-compatible punctured ring convolutional coded CPM on AWGN channel is simulated, and simulation results show that this system can provide good performance of bit error rate and variable-rate capabilities. Furthermore, simulation results also prove that the transmission efficiency increases when code rate is decreasing.
Cooperative Spectrum Sensing Based on Biological Learning Mechanism in Dynamic Electromagnetic Environment
Authors: Liu Qing , Wu Mu Qing , Zhang Ting Ting
Published: September 2012

Cognitive Radio is an intelligent radio that should be adapted to the time-varying environment. However, an adaptive fusion rule has been investigated by a rather limited work. In this paper, we present a new approach which is derived from the inspiration of human learning mechanism based on conditioning in behavioural theory. The framework and algorithmic flow are introduced. Moreover, the proposed method is proven to perform well in the dynamic circumstance by the result of the simulation.
Physico-Chemically Weighted Kernel for SVM Protein Classification
Authors: Jiang Hao , Ching Wai Ki
Published: September 2012

In this paper, a novel kernel taking into consideration of the physico-chemical properties of amino acids as well as the motif information is proposed to tackle the problem of protein classification. Similarity matrix is constructed based on an AAindex2 substitution matrix which measures the amino acid pair distance. Together with the motif content posing importance on the protein sequences, a new kernel is constructed. Numerical examples indicate that the string-based kernel in conjunction with SVM classifier performs significantly better than the traditional spectrum kernel method.
Automated Liver Segmentation for Cone Beam CT Dataset by Probabilistic Atlas Construction
Authors: Li Deng Wang , Wang Hong Jun , Chen Da , Yin Yong
Published: September 2012

Cone beam CT based image guided radiation therapy can be used to measure and correct positional errors for target and critical structures immediately prior to or during the treatment delivery. Data correlation between Planning CT images and daily CBCT images is the key issue for adaptive radiation therapy, including image registration and segmentation processing. In this paper, aiming for getting accurate liver contour structures automatically in daily CBCT images which is very low-contrast comparing the planning CT, probabilistic atlas is constructed from 50 high contrast planning CT images with manual delineation by oncologist. The incoming CBCT images are registered with the atlas using the deformable registration algorithm, and the liver contour structures are generated automatically by using the deformation map. The experiment results demonstrate the efficiency of our algorithm.
Research on Rate Adaptation Used Simulated Annealing Algorithm
Authors: Li Chang , Huang Lian Fen
Published: September 2012

This paper analyzes the PHY layer of IEEE 802.11 standards for a variety of transmission rate, after learned that MAC layer does not provide for its adaptive approach. With the study of various adaptive algorithms, the SAARF protocol based on simulated annealing algorithm is proposed on MAC Layer rate adaptation, which can adaptively adjust transmitting rate. Compared with ARF (Auto Rate Fallback) protocol, SAARF can more effectively improve the throughput from the simulation results.
Simulation and Performance Analysis of FH Spread Spectrum Communication System under Repeater Jamming
Authors: Zhang Yu , Sun Zhi Qiang , Lu Ji Hua , An Jian Ping
Published: September 2012

In this paper, a model of FH spread spectrum communication system has been built in Matlab/Simulink platform. Theoretical analysis of repeater jamming are derived. These limitations arise because of the geometry and so on. Then, we analyze the bit error rate performance in FH communication system under repeater jamming. The benefits of frequency hopping are potentially neutralized by a repeater jammer.
Simulation of Novel Three-Level Shunt Active Power Filter
Authors: Li Xing Gang , Feng Ren Yong , Kang Hai Zhen , Shi Zhi Guo
Published: September 2012

A new topology of shunt active power filter with two-leg three-level clamped capacitor in the main circuit is presented, and the operation principle and control scheme are introduced. The adopted device is operated as a controllable current source to eliminate current harmonics. The new hysteretic current comparison control scheme is used to track the command current and to balance the neutral-point voltage. Meanwhile the redundant operating states in the adopted inverter can be selected to compensate the clamped capacitor voltage to achieve the dynamic balance of the capacity voltage. Simulation results show that the shunt active power filter can effectively eliminate harmonics of the nonlinear loads.
Remote Wireless Monitoring System for Heading Face of Coal Mine Based on WMN
Authors: Feng Xiao Long , Zhou Zhi Yan , Wang Lu , Zhou Zhong Kuo
Published: September 2012

t is necessary to establish a remote wireless monitoring system for the heading face of coal mine because of the risk of gas outburst and water inrush. This paper introduced a remote wireless monitoring system for heading face of coal mine based on wireless mesh network. The key technology is that the wireless backhaul link of this wireless communication system must remain high bandwidth and low latency after multi-hop in order to support video transmission because the laneway of coal mine is narrow and long. We used the technology of multi-interface multi-channel to design a 2-interface 3-channel backbone network for this wireless communication system. Each node of this backbone network is equipped with two interfaces, and three orthogonal channels of channel 1,6,11 provided by 802.11b/g are used. Compared to single interface single channel chain network, the 2-interface 3-channel wireless mesh backbone network has high throughput and low end to end delay while using appropriate channel allocation algorithm to make the channels of adjacent links non-interfered.
Application in Anomaly Detection of Network Traffic Based on Fractal Technology
Authors: He Yue Mei , Wang Bao Min , Qiao De Jun
Published: September 2012

Fractal model is applicable to describe the complex shapes of nature. Self-similarity is the basic feature of fractal. Anomaly detection of network traffic is the key to security and reliability of network. In this paper, a new algorithm for anomaly detection of network traffic based on fractal technology is proposed. It can achieve higher precision with less space and time complexity. Theoretical analysis and experiments show that the method can discover the abnormal network traffic accurately and efficiently.
Adaptive Skipping Frame in TMN8 Rate Control
Authors: Huang Xiao Ping , Cao Ru Jun , Wang Peng Ying
Published: September 2012

The skipping frame algorithm in TMN8 rate control only depending on buffer state regardless of image characteristic, may skip important frames with large motion and, as a result, video quality seriously reduced. An adaptive skipping frame algorithm is proposed for low-bit rate real-time video encoding. The occurrence of frame skipping is jointly dependent on the temporal and spatial contents of the video, and achieves a balanced spatial and temporal quality to enhance the overall perceptual quality. Experimental results show that the proposed algorithm can achieve the better subjective and objective video quality than TMN8s algorithm, without introducing any computation complexity.
Plastic Deformation Effect on the Properties of 5754 Non Heat-Treatable Monitored via PAS, Hv and Resistivity
Authors: Hassan E.M. , Ibrahim Alaa M. , Abdel-Rahman M.A. , Badawi Emad A.
Published: September 2012

Defects are central to any understanding of material characteristics. They determine a host of material properties, including strength, ductility, resistivity and opacity. Positron annihilation spectroscopy (PAS) is a well-established high-sensitivity technique for detecting defects in solids. In this work, we study the influence of plastic deformation on the properties of 5754(AlMg3) aluminum alloy.
Depth Resolved Positron Annihilation Studies of Si and Metal Silicides
Authors: Amarendra G. , Abhaya S.
Published: September 2012

Depth resolved positron beam results of Si and metal silicides are highlighted in terms of identifying the nature of vacancy defects in amorphous and disordered Si and phase transformation and defect evolution as a consequence of silicide formation, respectively.
Positron Chemistry in Polymers
Authors: Kobayashi Yoshinori
Published: September 2012

Positron chemistry refers to chemical processes of high-energy positrons injected into molecular substances, the most interesting of which is the formation of positronium (Ps), the hydrogen-like bound state between a positron and an electron. Ps is formed predominantly by fast intra-track radiation chemical processes. In polymers it tends to be localized in intra/inter-molecular open space in the sparsely packed amorphous structure. Whilst short-lived singletpara-positronium (p-Ps) undergoes self-annihilation, the positron in long-lived tripletortho-positronium (o-Ps) annihilates with one of the spin opposite electrons bound in the surrounding polymer molecules. This process is called pick-off annihilation. The pick-off annihilation lifetime reflects the polymer chain packing through the size of the volume, where Ps is localized. Positrons are used to probe the amorphous structure of various polymeric systems. In this article, basic concepts and experimental techniques of positron chemistry in polymers as well as applications to the characterization of functional polymeric materials are overviewed.
Annihilation Lifetime Spectroscopy Using Positrons from Bremsstrahlung Production
Authors: Wagner Andreas , Anwand Wolfgang , Butterling Maik , Cowan Thomas E. , Fiedler Fine , Kempe Mathias , Krause-Rehberg Reinhard
Published: September 2012

A new type of a positron annihilation lifetime spectroscopy (PALS) system has been set up at the superconducting electron accelerator ELBE [ at Helmholtz-Zentrum Dresden-Rossendorf. In contrast to existing source-based PALS systems, the approach described here makes use of an intense photon beam from electron bremsstrahlung which converts through pair production into positrons inside the sample under study. The article focusses on the production of intense bremsstrahlung using a superconducting electron linear accelerator, the production of positrons inside the sample under study, the efficient detector setup which allows for annihilation lifetime and Doppler-broadening spectroscopy simultaneously. Selected examples of positron annihilation spectroscopy are presented.
Effects of Caeser Weed (Urena lobata L ) Fibre, Afara (Terminalia superba) and Mahogany (Khaya senegalensis) Dusts on some Physical and Mechanical Properties of Epoxy Resin
Authors: Dagwa Ishaya Musa , Ojo O.
Published: September 2012

In Recent Times, Environmental Concerns Arising from Pollution, Global Warming and Waste Management Have Led to the Generation of Interest in the Use of Environmentally Friendly Materials, Especially, Biological Materials such as Natural Fibres and Particulates in Composite Materials Manufacture. in this Work, Natural Fillers (Afara-Mahogany Particulates of 150µm) and Fibre (Caesar Weed Fibre of 5mm Length) Were Mixed with Epoxy Resin at the Various Fibre/filler Weight Percentages as Follows: 2%, 4%, 6%, 8% and 10% with Random Fibre Orientations. some Physical and Mechanical Properties of the Composite Were Determined Using Standard Procedures. Ninety (90) Wt% of Epoxy Resin Mixed with 10 Wt% for each of the Following: Caeser Weed Fibre, Afara and Mahogany, Improved the Tensile Modulus by 2652.6%, 321.37%, and 129.73% and the Impact Strength by 162.7%, 133.9% and 15.25%, Respectively. Also, Composites Density Reduced by 26.26%, 3.03%, and 3.03%, and its Hardness too Reduced by 5.41%, 1.35%, and 4.05%, Respectively. Meanwhile, the Water Absorption Were 4.9%, 2.79%, and 4.12% for 10wt% of Caeser Weed Fibre, Afara and Mahogany, Respectively and 90wt% Epoxy Resin. Therefore, Caeser Weed Fibre Had the Greatest Positive Effect on the Tensile Strength, Impact Energy Absorbed and Density. however, Afara-Epoxy Composite Had the Least Water Absorption and Higher Shore Hardness Value than Mahogany-Epoxy and Caeser Weed Fibre-Epoxy Composites.
Influence of Cubic Structured-ZnSnO3 Immersion Time to the Performance of Humidity Sensor
Authors: Md Sin Nor Diyana , Khadijah Noor , Mamat Mohamad Hafiz , Zaihidi Musa Mohamed , Rusop Mohamad
Published: September 2012

ZnSnO3 thin film was deposited at different deposition time (0.5 h, 2 h, 4 h and 6 h) using sol-gel immersion method and the electrical, optical and structural properties of this film was investigated. This research involved the preparation of nanostructured ZnO thin film by using RF magnetron sputtering, preparation of ZnSnO3 sol-gel solution, metal contact deposition and characterization of humidity sensor. The thin film was characterized using current-voltage (I-V) measurement (Keithley 2400) and field emission scanning electron microscopy (FESEM) (JEOL JSM 6701F) for electrical and structural properties respectively. The sensor was characterized using I-V measurement in a humidity chamber (ESPEC SH-261) and the chamber has been set at room temperature with varied relative humidity (% RH), in the range of 40-90% RH. The film prepared with a deposition time of 2 h shows better sensitivity for humidity sensor. The FESEM investigation shows that crystal size increases with the increasing deposition time.
Structural and Thermal Properties of ACNT by Modified Deposition Method: Growth Time Approach
Authors: Shamsudin Muhammad Salleh , Maryam Mohammad , Asnida Noor Asli , Zobir S.A.M. , Johari Mohd Amri , Yusop Shamsul Faez M. , Suriani A.B. , Abdullah Saifollah , Yahya S.Y.S. , Rusop Mohamad
Published: September 2012

The knowledge of fabrication method plays an important role in the preparation of aligned carbon nanotubes (ACNT) from natural hydrocarbon feedstock. Here ACNT were successfully synthesized by two-stage catalytic chemical vapor deposition method using organic oil (camphor oil) as a precursor. Synthesis was carried out at a fixed growth temperature of 800 °C and in different growth time: 10, 20, 30, 40, 50 and 60 minutes. The optimized condition for the growth of ACNT produced a small amount of by-product amorphous carbon and highly uniform crystal structure. The experimental results demonstrated that formation ACNT is also dependent on the growth time. The nanotubes were characterized by field emission scanning electron microscopy and micro-Raman spectroscopy. Thermal properties were evaluated by thermogravimetric analysis.
Identity at work: Exploring strategies for Identity Work
Authors: Adams Byron G. , Crafford Anne
Published: September 2012

Orientation: This study explored strategies for identity work that are central to the negotiation and regulation of employee work identity.Research purpose: The main aim of this study was to explore employee narratives and identify the strategies available to them in the process of identity work, as they defined themselves at work.Motivation for the study: As there is a scarcity of research on identity work in South Africa, this study wanted to advance knowledge about identity work and the strategies used for regulating and negotiating an identity at work by exploring these constructs in this context.Research design, approach and method: A qualitative research process formed the basis for this study. Nineteen employees from a global manufacturing company participated in two semi-structured in-depth interviews. Grounded theory was applied to analyse and interpret the data.Main findings: Nine strategies for identity work were identified and categorised into four broad themes (personal philosophies; relationships; career management and negotiating balance).Practical/managerial implications: Employees followed various strategies for defining themselves at work and this may have some implications for employee work engagement and productivity.Contribution/value-add: This study expands on current theoretical knowledge of identity work, and provides insights into the strategies people use to regulate and negotiate their identities at work.
Integration of Problem‐Based Learning and Web‐Based Multimedia to Enhance a Soil Management Course
Authors: Strivelli Rachel A. , Krzic Maja , Crowley Chris , Dyanatkar Saeed , Bomke Arthur A. , Simard Suzanne W. , Jakoy Andy
Published: September 2012

In an attempt to address declining enrollment in soil science programs and the changing learning needs of 21st century students, several North American universities have re‐organized their soil science curriculum and adopted innovative educational approaches and web‐based teaching resources. An interdisciplinary team set out to integrate teaching approaches to address this trend. The objective of this project was to develop a web‐based teaching tool, which combined a face‐to‐face problem‐based learning (PBL) case study with multimedia to illustrate the impacts of three land‐uses on soil transformation and quality. The Land Use Impacts (LUI) tool (http://soilweb.landfood.ubc.ca/luitool/; verified 4 Oct. 2011) was a collaborative and concentrated effort to maximize the advantages of two educational approaches—the web's adaptability and accessibility, and PBL's capability to foster an authentic learning environment, apply core concepts, and encourage group work. The design of the LUI case study was guided by Herrington's development principles for web‐based authentic learning. The LUI tool presented students with rich multimedia (streaming videos, text, data, photographs, maps, and weblinks) and real world tasks (site assessment and soil analysis) to encourage students to utilize knowledge of soil science in collaborative problem‐solving. Preliminary student feedback indicated that the LUI tool conveyed case study objectives and was appealing to students. The tool is intended primarily for students enrolled in an upper level undergraduate/graduate university course titled Sustainable Soil Management, but it is flexible enough to be adopted for other natural resource courses.
Does Increased Funding for Homeless Programs Reduce Chronic Homelessness?
Authors: Moulton Shawn
Published: September 2012

This article tests whether programs that provide housing assistance to homeless people can reduce chronic homelessness. I analyze data from the Department of Housing and Urban Development for 130 communities across the United States over the period 2005 to 2007. Because the amount of federal money allocated to a community to combat homelessness may depend on unobserved characteristics of that community, I estimate a fixed‐effects model that estimates the effect of new federal homeless funding on chronic homelessness. I find that the first‐year cost of moving one chronically homeless person into permanent supportive housing is $55,600. An analysis of new funding to specific types of homeless programs indicates that programs that provide long‐term housing and services to homeless people with disabilities drives this relationship.
Face Value: Information and Signaling in an Illegal Market
Authors: Logan Trevon D. , Shah Manisha
Published: September 2012

Economists argue that rich information environments and formal enforcement of contracts are necessary to prevent market failures when information asymmetries exist. We test for the necessity of formal enforcement to overcome the problems of asymmetric information by estimating the value of information in an illegal market with a particularly rich information structure: the online market for male sex work. We assemble a rich data set from the largest and most comprehensive online male sex worker Web site to estimate the effect of information on pricing. We show how clients of male sex workers informally police the market in a way that makes signaling credible. Using institutional knowledge, we identify the specific signal male sex workers use to communicate quality to clients: face pictures. We find that there is a substantial return to the signal in this market. The findings provide novel evidence on the ability of rich information environments to overcome problems of asymmetric information without formal enforcement mechanisms.
Remittances, Monetary Policy, and Partial Sterilization
Authors: Vacaflores Diego E.
Published: September 2012

Remittances play a large and important role in certain economies, where they became a significant share of GDP. Official government records of these flows have been systematically improved since governments realized their importance, but a significant percentage of remittances remain unrecorded. This, together with the shadow economy, may pose a problem for monetary policy. This article uses a limited participation model to examine the differential effect that higher shares of remittances can have on monetary policy and describes the impact of remittances on a small open economy under partial sterilization. It demonstrates how a typical monetary shock will lead to a more pronounced liquidity effect when remittances become a higher proportion of GDP. It also shows that a positive remittance shock improves consumption and lowers interest rates, but as it also reduces work effort it momentarily lowers output. Such dynamics are exacerbated as the degree of partial sterilization is accentuated.
Real Interest Rate and Labor Market Performance around the World
Authors: Feldmann Horst
Published: September 2012

This article studies the effects of the real interest rate on labor market performance. Using a much larger sample of countries and more indicators of labor market performance than have been used in previous articles, it finds that a rise in the real interest rate increases the unemployment rate, raises the share of long‐term unemployed, and reduces the employment rate. The magnitude of these effects is very small in the short run but much more pronounced—though still fairly small—in the long run. Young people are disproportionately affected. The results are robust to variations in specification.
Real-time delay statistics in wireless IP networks
Authors: Huo D.
Published: September 2012

Abstract. In the wireless communication, the variation of the transmission delay is called jitter and is one of the variables responsible for the degradation of the service quality. Jitter is present in every section of the transmission system. Its stochastic behavior depends on the technology implemented in the system and the service provided by the system. This paper focuses on mathematical modeling and phenomenological analysis of the jitter encountered by the real-time services in a wireless network. Using the data made available to the public by the wireless industry, we explore the stochastic characterizations of the jitter in a wireless IP networks. Within the scope of real-time service, we studied the relation between delay, jitter and the inter-packet time. Evaluation of the sample data indicates a long range dependence of the inter-packet time of the received packets in a real-time connection. The result helps understanding the transmission delay encountered by the real-time service over wireless IP networks.
An EMC study of an electrical powertrain for transportation systems
Authors: Chand B. , Hähre K. , Keghie J. , Dickmann S.
Published: September 2012

Abstract. There are many reasons, why electric drive systems will be used in future more frequently in transportation systems. The electrification allows a flexible use of different energy sources and thus creates a greater independence from fossil energy. However, electric drive systems are a challenge for the manufacturers of transportation systems. The electrical powertrain can not only be exposed to interferences, it may also emit interferences into components and communication cables in the vicinity. This can be a high risk for the drive system and for the passengers. For that reason, an EMC study of an electrical powertrain for transportation systems is presented. There the interference at the unshielded high-voltage cable (HV-cable) is characterized. The analysis of the influence of position variation of the communication cable with respect to the unshielded HV-cables is one main aspect. Different optimizations have been added to the test setup.
EUV-TEC proxy to describe ionospheric variability using satellite-borne solar EUV measurements
Authors: Unglaub C. , Jacobi Ch. , Schmidtke G. , Nikutowski B. , Brunner R.
Published: September 2012

Abstract. An updated version of a proxy, termed EUV-TEC, describing the global total primary photoionisation is calculated from satellite-borne EUV measurements assuming a model atmosphere consisting of four major atmospheric constituents. Regional number densities of the background atmosphere are taken from the NRLMSISE-00 climatology. For calculation the Lambert-Beer law is used to describe the decrease of the radiation along their way through the atmosphere. The EUV-TEC proxy thus describes the ionospheric response to solar EUV radiation and its variability. EUV-TEC is compared against the global mean total electron content (TEC), a fundamental ionospheric parameter created from vertical TEC maps derived from GPS data. Strong correlation between these indices is found on different time scales. Results show that the EUV-TEC proxy represents the ionsopheric variability better than the conventional solar index F10.7 does, especially during high and moderate solar activity.
Beam-Splitting in plasmonic multimode waveguides based on the self-imaging effect
Authors: Edelmann A. , Helfert S. , Jahns J.
Published: September 2012

Abstract. A plasmonic 1 × 2 beamsplitter based on the self-imaging effect is analysed. The simulations were performed by a 3-D full-vectorial numerical calculation. We discuss the coupling efficiency depending on structural parameters and on the attenuation.
Future Arctic marine access: analysis and evaluation of observations, models, and projections of sea ice
Authors: Rogers T. S. , Walsh J. E. , Rupp T. S. , Brigham L. W. , Sfraga M.
Published: September 2012

Abstract. There is an emerging need for regional applications of sea ice projections to provide more accuracy and greater detail to scientists, national, state and local planners, and other stakeholders. The present study offers a prototype for a comprehensive, interdisciplinary study to bridge observational data, climate model simulations, and user needs. The study's first component is an observationally-based evaluation of Arctic sea ice trends during 1980–2008, with an emphasis on seasonal and regional differences relative to the overall pan-Arctic trend. Regional sea ice los has varied, with a significantly larger decline of winter maximum (January–March) extent in the Atlantic region than in other sectors. A lead-lag regression analysis of Atlantic sea ice extent and ocean temperatures indicates that reduced sea ice extent is associated with increased Atlantic Ocean temperatures. Correlations between the two variables are greater when ocean temperatures lag rather than lead sea ice. The performance of 13 global climate models is evaluated using three metrics to compare sea ice simulations with the observed record. We rank models over the pan-Arctic domain and regional quadrants, and synthesize model performance across several different studies. The best performing models project reduced ice cover across key access routes in the Arctic through 2100, with a lengthening of seasons for marine operations by 1–3 months. This assessment suggests that the Northwest and Northeast Passages hold potential for enhanced marine access to the Arctic in the future, including shipping and resource development opportunities.
Influence of Soybean (Glycine max) Population and Herbicide Program on Palmer Amaranth (Amaranthus palmeri) Control, Soybean Yield, and Economic Return
Authors: Hoffner Amy E. , Jordan David L. , York Alan C. , Dunphy E. James , Everman Wesley J.
Published: September 2012

Palmer amaranth (Amaranthus palmeri S. Wats) has become one of the most prominent and difficult weeds to control in soybean (Glycine max (L.) Merr.) in North Carolina. A survey was conducted in North Carolina during fall 2010 to estimate the magnitude of this problem. Palmer amaranth was present in 39% of 2,512 fields representing 0.24% of soybean ha in North Carolina. In recent years, growers have reduced soybean seeding rates in an effort to decrease production costs associated with technology fees. However, given the increase in prevalence of Palmer amaranth and the difficultly in controlling this weed due to herbicide resistance, growers may need to reconsider reductions in seeding rates. Therefore, research was conducted during 2010 and 2011 to determine if Palmer amaranth control, soybean yield, and economic return were affected by soybean plant population, preemergence (PRE) and postemergence (POST) herbicides, and herbicide resistant traits (glufosinate-resistant and glyphosate-resistant cultivars). Applying PRE or POST herbicides and increasing soybean population increased Palmer amaranth control, soybean yield, and economic return when compared with POST herbicides only or when lower soybean populations were present. Efficacy of glufosinate and glyphosate did not vary in most instances, most likely because these herbicides were applied timely, and the frequency of glyphosate resistance did not exceed 10% in these fields.
Development and Validation of Teacher Curriculum Paradigm Instrument
Authors: Foi Liew Yon , Bakar Kamariah Abu , Hamzah Mohd Sahandri Gani , Alwi Nor Hayati
Published: September 2012

This is the first psychological based instrument which has been developed and validated to measure the latent variable teacher curriculum paradigm (TCP) that was derived from Kuhn’s (1970) epistemology of paradigm and further adapted to the ideas of Henderson and Gornik (2007), Schubert (1986), Tanner and Tanner (2007), Tuthill and Ashton (1983), and Zeichner’s (1983) paradigms for the curriculum development field. The TCP instrument followed the rigorous research design and methodology to serve as the vital procedures of attaining the internal validity for the developed instrument. Subsequently, the TCP instrument was content validated by three subject experts and gone through three phases of instrument testing with three independent samples (N1=34, N2=72, and N3=553, respectively) taken from the same population of in-service teachers in the Peninsular of Malaysia. Moreover, the SEM approach was utilized to further validate the construct validity of the scores for the TCP instrument. In light of the systematic data collection and robustness of the SEM confirmatory procedures, the attaining of a very high psychometric properties to the TCP instrument. Coherently, these findings had strongly supported that the TCP instrument is a reliable and valid tool for measuring TCP of in-service teachers in Peninsular of Malaysia.   Keywords - instrument development, instrument validation, teacher curriculum paradigm, structural equation modelling, construct validity
Singapore Experience of the HRM and Tourism Students of Lyceum of the Philippines University in the Context of Cross Cultural Orientation Initiatives
Authors: Felicen Sevillia S. , Celis Mark Irvin C.
Published: September 2012

This study aimed to determine the “Cross-Cultural awareness of HRM and Tourism students in Singapore”. Specifically, level of cross-cultural orientation of the SIAP participants in terms of customs and tradition, language and tourism and hospitality industry practices; the significant relationship between the profile of the respondents and their level of cross-cultural orientation and programs that may be implemented to increase the level of cross-cultural orientation among future SIAP participants. This study also aimed to determine the experiences and challenges met by the HRM and Tourism student in Singapore because this will be helpful for the college in developing various programs and interventions for the students’preparation in the program. The descriptive method of research was used in the study. Instruments like questionnaire and interview were further utilized in gathering the primary data. The data gathered were statistically treated using the percentage, weighted mean and the eta- squared. The result revealed that most of the respondents have equal chances of being placed in a Student Internship Abroad Program (SIAP) exposure regardless of the selected profile variables. They have an adequate level of cross cultural awareness to the customs and traditions, values and languages and tourism hospitality practices.   Keywords - Cross-cultural, Student Internship Abroad Program
Generating Validated 3D Models of Microporous Ceramics
Authors: Schmidt Kilian , Becker Jürgen
Published: September 2012

Methods of generating and validating 3D models of microporous ceramics and computing the porosity and permeability by means of these models are presented. For five cordierite ceramic variants from the application area of diesel particulate filters, generated structure models with computed porosities and permeabilities are depicted. The generated pore structures are compared to the real structures by the chord length distribution. Furthermore, the computed porosities and permeabilities are compared to measurements.
Reactive Filters for Steel Melt Filtration
Authors: Aneziris Christos G. , Dudczig Steffen , Emmel Marcus , Berek Harry , Schmidt Gert , Hubalkova Jana
Published: September 2012

New carbon bonded Al2O3 filters with Magnesia–carbon (MgO–C) “reactive coatings” for high filtration efficiency of steel melts are studied with the aid of a special steel casting simulator in full controlled atmosphere. Due to the in situ reduction of MgO in the MgO–C coating and the formation of Mg vapor a reaction with the oxygen dissolved in the steel melt is triggered and leads to the formation of secondary MgO on the filter surface. With this approach not only primary and secondary inclusions can be effectively removed from the steel melt, but as well as less tertiary and quartenary inclusions can be expected due to less oxygen dissolved in the steel melt.
Silicosis exposure–response in a cohort of tin miners comparing alternate exposure metrics
Authors: Park Robert M. , Chen Weihong
Published: September 2012

Background.

The detailed lung radiographic response to silica exposure has not been described. In estimating the exposure–response relationship in silicosis with statistical models, the absence of baseline (unattributable) risk can disable relative‐rate estimation or produce widely varying estimates. This obstructs identification of optimum exposure metrics and invalidates comparisons and meta‐analyses, which assume a common background rate.

Methods.

A cohort of 3,000 Chinese tin miners with more than 1,000 cases of silicosis was analyzed for the period 1961–1994. Regular surveillance documented three stages of silicosis. To examine the exposure–response relationship, the intercept in relative‐rate models was fixed to correspond to 1% of the observed silicosis rate. Exposure metrics for contributions in different time‐windows were simultaneously evaluated, as were burden and cumulative burden metrics.

Results.

Silica exposures that most contributed to silicosis onset occurred in the period 5–10 years prior (excess annual rate per 10 mg‐year/m3, ER = 0.158, 95% CI = 0.125–0.192, or 16% per year). During 10–20 year prior, the excess rate contribution was much smaller (ER = 0.048, 95% CI = 0.037–0.060) but larger again during 20–30 year prior to onset (ER = 0.112, 95% CI = 0.098–0.126). For advanced silicosis, all time periods contributed about equally to the rate of onset.

Conclusions.

Reliable estimates of parameters were observed, demonstrating exposure contributions over time. Burden metrics with different half‐lives suggested some reversibility for silicosis onset with a half‐life of 20 years. Advanced silicosis was best predicted with a cumulative burden metric which was consistent with prior observations that previously deposited silica continues to cause pulmonary damage. Am. J. Ind. Med. 56:267–275, 2013. © 2012 Wiley Periodicals, Inc.
The effect of occupational exposure to benzo[a]pyrene on neurobehavioral function in coke oven workers
Authors: Qiu Chongying , Peng Bin , Cheng Shuqun , Xia Yinyin , Tu Baijie
Published: September 2012

Background

Coke oven workers are regularly exposed to polycyclic aromatic hydrocarbons (PAHs). Benzo[a]pyrene (B[a]P), known as an indicator species for PAH contamination, is a neurobehavioral toxicant. The purpose of the study was to evaluate the relationship between B[a]P exposure, a B[a]P‐related urinary metabolite and neurobehavioral function among coke oven workers.

Methods

Coke oven workers and oxygen factory workers participated in this study. B[a]P exposure was monitored by air sampling pump, and urinary 1‐hydroxypyrene (1‐OHP) level was detected with high performance liquid chromatography (HPLC). A questionnaire and the neurobehavioral core test battery (NCTB) were administered to all subjects.

Results

B[a]P‐exposed workers were found to have higher urinary 1‐OHP levels and worse NCTB performances on eight items than control workers. B[a]P concentrations were higher in the coke oven plant than that in the controls' workplace. The performances on simple reaction time, correct pursuit aiming, and error pursuit aiming decreased with increasing airborne B[a]P in coke oven workers. There were significant correlations between urinary 1‐OHP level and six items of the NCTB.

Conclusions

Occupational exposure to B[a]P is associated with neurobehavioral function impairment in coke oven workers. Am. J. Ind. Med. 56:347–355, 2013. © 2012 Wiley Periodicals, Inc.