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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Soziokulturelle Theorie und Selbstdarstellung von Lernenden in einem interaktiven online L2 Lernkontext

Sauer, Philipp Marco Wolfgang January 2008 (has links)
Abstract This study in second language acquisition (SLA) investigates the influence of self-portrayal of language learners in an interactive online L2 learning environment from a social-interactionist research perspective. This thesis has a mainly theoretical focus and will integrate concepts of online communication with SLA methodology. This work reviews some classical perspectives on chats and message boards as environment for online communication in chapter two and develops a list of features to classify them from a second language acquisition perspective. In order to assist the main argument of the thesis that an integrated view of learners within a learning context is necessary to fully use the advantages of an interactive online learning environment, the second language acquisition model of Marysia Johnson (2004) is discussed in chapter three. Using the premises of the model, which result from the application of Lev Vygotskys sociocultural theory and Mikhail Bakhtins dialogized heteroglossia, key features for the later data analysis are pointed out. Those are the dismissal of the separation of language competence and language performance, a view of language that exceeds mere morphosyntactical concerns and the overcoming of the mainstream mentalist SLA approach in favor of a socioculturally oriented dialogical language learning model. The approach of Bonny Norton (2000) to identity is used as an analytical framework to complete Johnsons model developing a methodology for chapter four. The data analysis in chapter five is used to prove the validity of the model in showing that the developed model is applicable for the analysis of an online context. After a description of the course environment and a preliminary analysis, an in depth qualitative approach is used to point out the links between sociocultural theory and identity theory. Afterwards, I will give a short summary of my most important results and finish my thesis with some suggestions for further research.
182

µProfiler: A Concurrent Profiler for Concurrent C++ (µC++)

Gidzinski, Justyna Jay January 2007 (has links)
A concurrent program, unlike a sequential program, has multiple threads of execution, resulting in numerous advantages (e.g., faster execution), but also in complex and unpredictable interaction. As a consequence, a concurrent program can easily underutilize available parallelism, and performance can be extremely difficult for users to predict and analyze on their own. A profiler is a tool that can help a user identify as well as locate potential performance problems in a program. Profiling is accomplished through monitoring of the program execution, and analyzing and visualizing the collected performance data. A profiler must display useful information in a way that allows a user to effectively and efficiently understand and analyze a program's behaviour. This thesis describes the advancement in design and implementation of µProfiler, a profiler for sequential and concurrent programs written in µC++. µC++ is a concurrent dialect of the C++ programming language, which executes in uni-processor and multi-processor shared-memory environments. Major advancements to three µProfiler metrics are presented: the Execution State, the Exact Routine Call-Graph and the Statistical Routine Call-Graph. The Execution State metric charts each state for every thread over the entire execution of the program. With high overhead and perfect accuracy, the Exact Routine Call-Graph metric provides an exact call-graph profile of the program's dynamic execution, describing the control flow among routines. With low overhead and less accuracy, the Statistical Routine Call-Graph metric provides a statistical call-graph profile of the program's dynamic execution. For each metric, advancements were made throughout the profiling process (i.e., monitoring, analysis and visualization), addressing goals such as scalability, functionality, usability and performance. The metrics provide reasonable memory overhead and, based on the comparison to related work, are state-of-the-art in functionality and provide similar run-time performance.
183

Soziokulturelle Theorie und Selbstdarstellung von Lernenden in einem interaktiven online L2 Lernkontext

Sauer, Philipp Marco Wolfgang January 2008 (has links)
Abstract This study in second language acquisition (SLA) investigates the influence of self-portrayal of language learners in an interactive online L2 learning environment from a social-interactionist research perspective. This thesis has a mainly theoretical focus and will integrate concepts of online communication with SLA methodology. This work reviews some classical perspectives on chats and message boards as environment for online communication in chapter two and develops a list of features to classify them from a second language acquisition perspective. In order to assist the main argument of the thesis that an integrated view of learners within a learning context is necessary to fully use the advantages of an interactive online learning environment, the second language acquisition model of Marysia Johnson (2004) is discussed in chapter three. Using the premises of the model, which result from the application of Lev Vygotskys sociocultural theory and Mikhail Bakhtins dialogized heteroglossia, key features for the later data analysis are pointed out. Those are the dismissal of the separation of language competence and language performance, a view of language that exceeds mere morphosyntactical concerns and the overcoming of the mainstream mentalist SLA approach in favor of a socioculturally oriented dialogical language learning model. The approach of Bonny Norton (2000) to identity is used as an analytical framework to complete Johnsons model developing a methodology for chapter four. The data analysis in chapter five is used to prove the validity of the model in showing that the developed model is applicable for the analysis of an online context. After a description of the course environment and a preliminary analysis, an in depth qualitative approach is used to point out the links between sociocultural theory and identity theory. Afterwards, I will give a short summary of my most important results and finish my thesis with some suggestions for further research.
184

Daily Calls Volume Forecasting

AJMAL, KHAN, TAHIR MAHMOOD, HASHMI January 2010 (has links)
A massive amount has been written about forecasting but few articles are written about the development of time series models of call volumes for emergency services. In this study, we use different techniques for forecasting and make the comparison of the techniques for the call volume of the emergency service Rescue 1122 Lahore, Pakistan. For the purpose of this study data is taken from emergency calls of Rescue 1122 from 1st January 2008 to 31 December 2009 and 731 observations are used. Our goal is to develop a simple model that could be used for forecasting the daily call volume. Two different approaches are used for forecasting the daily call volume Box and Jenkins (ARIMA) methodology and Smoothing methodology. We generate the models for forecasting of call volume and present a comparison of the two different techniques.
185

Monitoring Marine Mammals in Onslow Bay, North Carolina, Using Passive Acoustics

Hodge, Lynne Elizabeth Williams January 2011 (has links)
<p>Passive acoustic monitoring is being used more frequently to examine the occurrence, distribution, and habitat use of cetaceans. Long-term recordings from passive acoustic recorders allow the examination of diel, seasonal, and inter-annual variation in the occurrence of vocalizing marine mammals. With the increased use of passive acoustics as a tool for studying marine mammals, the ability to classify calls to the species level is becoming more important. While studies have found distinctive vocalizations in some cetacean species, further work is required in order to differentiate the vocalizations of delphinid species. I sought to classify odontocete vocalizations to species and to describe temporal variation and depth-related differences in the occurrence of cetacean vocal events detected in archival passive acoustic recordings in Onslow Bay, North Carolina. To determine if odontocete species in offshore waters of North Carolina could be distinguished by their whistles and clicks, I used a towed hydrophone array to make acoustic recordings of species encountered during concurrent visual and acoustic surveys between 2007 and 2010. I recorded whistles from four species (Atlantic spotted dolphins, bottlenose dolphins, rough-toothed dolphins, and short-finned pilot whales) and clicks from five species (Risso's dolphins in addition to the four species listed above). After running a classification and regression tree (CART) analysis on 22 measured variables from the contours of four species' whistles, I generated an optimal classification tree that had a correct classification rate of 74.2%. My results indicate that species-specificity exists in the four species' whistles. My examination of the spectral structure of clicks showed that only Risso's dolphins produced clicks with distinctive spectral banding patterns, although I found that other click parameters, particularly peak and center frequency, might be useful in differentiating the other species. I then used the distinctive banding pattern that I observed in Risso's dolphin clicks to identify this species in recordings made by archival passive acoustic recorders that were deployed at various times and locations between 2007 and 2010. I used these recordings to determine how vocal events varied temporally and spatially in Onslow Bay. My analysis of vocal events observed in these recordings showed that Risso's dolphins, sperm whales, and other delphinids are present in Onslow Bay throughout the year; Kogia spp. occur sporadically; and fin and minke whales produce calls that can be detected only between late fall and early spring. I also detected low-frequency downsweeps and two types of low-frequency pulse trains produced by unknown species. After looking at the occurrence of fin whale 20-Hz pulses in relation to downsweeps, I suggest that the downsweeps are produced by sei whales due to the lack of overlap in occurrence. When I looked for diel patterns in the odontocete vocal events, I found a nocturnal increase in the occurrence of clicks from Risso's dolphins and sperm whales, but no diel variation in Kogia clicks. I also found that unidentified delphinids showed either an increase in click events at dawn or at night, depending on the time of year and recording location. Finally, my analysis of acoustic data from five recorders deployed in three different depth ranges revealed that there was greater unidentified delphinid and sperm whale vocal activity on recorders located in deep waters, suggesting a greater diversity and density of animals in deeper waters of Onslow Bay. Together, the results of my dissertation demonstrate the value of passive acoustic monitoring in understanding the distribution and temporal trends in cetacean occurrence, and highlight the importance of classifying sounds to the species level in order to better understand the temporal and spatial patterns found.</p> / Dissertation
186

Dependent Hierarchical Bayesian Models for Joint Analysis of Social Networks and Associated Text

Wang, Eric Xun January 2012 (has links)
<p>This thesis presents spatially and temporally dependent hierarchical Bayesian models for the analysis of social networks and associated textual data. Social network analysis has received significant recent attention and has been applied to fields as varied as analysis of Supreme Court votes, Congressional roll call data, and inferring links between authors of scientific papers. In many traditional social network analysis models, temporal and spatial dependencies are not considered due to computational difficulties, even though significant such dependencies often play a significant role in the underlying generative process of the observed social network data.</p><p>Thus motivated, this thesis presents four new models that consider spatial and/or temporal dependencies and (when available) the associated text. The first is a time-dependent (dynamic) relational topic model that models nodes by their relevant documents and uses probit regression construction to map topic overlap between nodes to a link. The second is a factor model with dynamic random effects that is used to analyze the voting patterns of the United States Supreme Court. hTe last two models present the primary contribution of this thesis two spatially and temporally dependent models that jointly analyze legislative roll call data and the their associated legislative text and introduce a new paradigm for social network factor analysis: being able to predict new columns (or rows) of matrices from the text. The first uses a nonparametric joint clustering approach to link the factor and topic models while the second uses a text regression construction. Finally, two other models on analysis of and tracking in video are also presented and discussed.</p> / Dissertation
187

Outsourcing Employee Turnover in The Customer Service Department -- Using the Grounded Theory to Construct The Cause-Effect Model

Chang, Pei-jung 29 January 2004 (has links)
The outsourcing business of the call center grew enormously in recent years, but there were only a few studies focused on the outsourcing employees, especially the turnover problems and related issues, which were deeply concerned by call center supervisors. This research aims to comprehend the turnover problems of the outsourcing employees; in addition, what policies the managers of the call centers adopt to solve the turnover problems. This is a one-case study. The qualitative research methodology follows the principles of the grounded theory. Eight supervisors of different call centers in the company were interviewed during April to November in 2003. The data collection and analysis is a long process of hard working. The research findings can be concluded as the following three aspects. The first is that the high turnover rates of outsourcing employees cause serious problems to various call centers. The unstable manpower quality and the lower department morale would generate inconsistent customer services. It turns out the operation costs increase as well as the outsourcing cost. Because of the strong impact to the operation in each call center, supervisors have adopted several approaches in order to solve the turnover problems in the last few years. The most significant improvement is from the following efforts, such as clarifying the basic salary and benefit for the outsourcing employees in the outsourcing contract, training the back-up personnel, and improving the management skills of the vendors. For the second aspect of the research findings, we conclude that the turnover problem is caused by the internal organizational factors and the external organizational factors. The internal factors contain the working environment associated with the climate, and the administration policy or style. The external factors include the personal concerns of outsourcing employees, and the vendor problems. Furthermore, there are two intervening conditions: employees¡¦ personality and working life quality. That would reinforce the influential factors to the turnover problem and action/interaction strategies. Finally, some of the empirical results of this research are consistent to the literatures about the call center operation. By improving recruit process, employee training and encouraging policy, it may lower the turnover rate that may result in a better quality of customer service, and then have the outsourcing cost down.
188

To explore makings to set up a Call Center in Business

Lin, Yi-Hui 30 January 2004 (has links)
Due to the advance in computer and communication technology, businesses¡¦ Customer Relationship Management¡]CRM¡^, of which the call center is a critical component, has relied more and more technology to meet customer needs in order to become more competitive. In the Call Center, staffs provide customers with various services by phone or via face-to-face communication. Since customer relationship may influence profits and growth of the company, the quality of the call center becomes a key factor of successful CRM. In this study, a case study based on in-depth interviews is conducted to investigate the critical successful factors of the Call Center. The results show that first, at the strategy level, it is critical for companies to incorporate IT into business strategies and compass the orientation of the Call Center to adapt to the changing business environment. Next, at the organization level, the implementation of new system is a challenge to the organization¡¦s structure, working procedure, and collaboration system. Therefore, before the implementation, the company should form a business-wide plan and make the staffs understand the demands and benefits of new system. It is also critical for the company to develop an empowerment culture and to value the voice of the front-line staffs. Lastly, at the Information Technology level, it is critical to adopt stable and continuous information technology.
189

The Impact and Pricing Formula of the National Finance Stabilization Fund: Application of the Barrier Option

Chan, Chieh-chung 07 August 2006 (has links)
In the first part of this article, we discuss the time and the probability for the barrier option to become effective, and then employ the risk neutral assumption to derive the pricing formula of the barrier option. Our pricing formula is a closed form solution, and we may calculate the price of the barrier option without considering the Binomial tree of the underlying asset. We also calculate the traditional option price by our pricing formula, and compare the result to the value that is calculated by Binomial pricing formula. Both of them give the same value about the tradition option, and thus we may regard the tradition option as the special case of the barrier option. In the second part of this article, we employ the pricing formula of the barrier to derive the value of the National Finance Stabilization Fund, and then analyze the impact of the NFSF to the market. Our results reveal that when the benchmark market is not shifted by the bad news, then the NFSF may advance and stabilize the stock price index. In fact, many new style derivatives have the characteristics like barrier option, for example, a convertible bond with forced convert clause, which is a up-and-out call. Other course like bankruptcy costs, agency problems, and contingent liabilities etc, which can all be solved by the pricing formula in our discussion. We hope that results and the process in this article are helpful in solving above questions.
190

A Dynamic Channel Allocation Mechanism with Priorities in Wireless Networks

Lin, Hsin-Yuan 27 July 2000 (has links)
Pico-Cellular architecture fully reuses frequency to increase network capacity. However, it will increase the occurance of Handoff due to the small range of cell. Previous works in channel allocations can reduce blocking probability of handoff call, but it may increase blocking probability of new call. As a result, channel utilization is decreased because they can not adapt to network changes. In this thesis, we present a Dynamic Channel Allocation Mechanism with priority support. All channels and calls are divided into high and low priority. If there is no high_priority channel for high_priority call, high_priority call may downgrade its priority by sacrificing some QoS to utilize low_priority channels. We define two new array for network information status, one is next_cell state, and the other is the transition probability. Next_cell state is used to save prior M Cell_Ids where handoff calls may move to. Transition probability is used to save the probabilities for active calls moving to other neighboring cells. According to next_cell state and transition probability, we can accurately predict the probabilities for mobile hosts moving to other neighboring cells. Therefore, we can dynamically adjust bandwidth reservation requests sending to neighboring cells by the latest transition probability and the number of active calls in this cell. We analyze the proposed mechanism through a mathematical model. In the model, we build a four-dimension Markov Chain and use MATLAB[41] tool to evaluate blocking probability, channel throughput and utilization. We found out that blocking probability of handoff call can be decreased and channel utilization can be increased through the proposed channel allocation mechanisms with high and low priority support.

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