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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.
451

Fiberföstärkning av Limträbalkar

Jarrin Peters, David January 2013 (has links)
Glulam is a product that was engineered to make use of timber in a more efficient way. Bychoosing timber of similar quality and discarding natural defects during production, thedevelopment of a stronger cross-section is achieved.Carbon fiber is a relatively new material with a high tension capacity. This feature is used toexamine how the bending capacity of the beams improve by adhering carbon fiber laminateson the lower edge of the beamsThe strength of the material is tested with three experiments: carbon fiber on the bottom of thebeam (a), carbon fiber attached to the lower sides of the beam (b) and carbon fiber in thebeam, covered with a layer of wood (c) The results show that the first case, where the carbon fiber is attached to the bottom of thebeam, gave the best result with an increase in capacity of 59 % compared to the nonreinforcedcontrol. The other two cases also show an improvement in capacity, beam-type 3had a capacity increase of 47% and beam-type 4 increased with 25 %Tests were also made with glulam beams reinforced with fiberglass, but these tests were notanalyzed in depth because the purpose was to compare the capacity to carbon fiber. Thisbeam improved its capacity by 40.3%.The tests show that carbon fiber as a reinforcement material for glulam is a good choice whenthere is a requirement for stronger cross-sections in both new production and renovation ofold buildings. However there are some disadvantages to carbon fiber, for example costs andincreased demands on work environment, which makes steel a cheaper option.
452

Job Shop Scheduling Focusing on Role of Buffer

HINO, Rei, KUSUMI, Tetsuya, YOO, Jae-Kyu, SHIMIZU, Yoshiaki 09 1900 (has links)
No description available.
453

To Use the Codebook Information or Not: A Study of the Compress-and-Forward Relay Strategy

Wu, Xiugang January 2009 (has links)
The motivation of this thesis is to understand how nodes can cooperate in a particular relay channel, say a relay channel with orthogonal link between relay and destination. We are especially interested in the scenario where relay cannot decode the message sent because the coding rate is too large vis-a-vis what it can handle, and try to investigate the optimality of compress-and-forward strategy for this scenario. Specifically, noting that relay's compression is based on the unconditional distribution of its observation, it is natural to ask if relay can do better if it utilizes the source's codebook information, such that the performance of the relay network is improved? To answer this key question, we need to find the posterior Conditional Distribution of channel Output given Codebook Information (namely CDOCI) for the channel between source and relay. Firstly, we model it as Binary Symmetric Channel (BSC) and show that under the now standard random coding framework, if the input distribution is uniform, then with high probability, the CDOCI is asymptotically uniform when coding rate is greater than the channel capacity and the block length is sufficiently large. Then it is shown that under the discrete memoryless channel (DMC), for those strongly typical output sequences, with high probability, the CDOCI is also asymptotically uniform and close to the unconditional distribution, for rate above capacity and sufficiently large block length. These results implicate that relay can hardly do better with codebook information used. To confirm this implication, we show that for sufficiently large block length, the rate needed for relay to forward its observation when the codebook information is utilized approaches the rate needed when the relay simply ignore the codebook information, if the coding rate at source is larger than channel capacity. Now the answer to the above key question is apparent: in the cases of BSC and DMC, even if the relay tries to utilize the information obtained by knowing the codebook used at the source, it can hardly do better than simply ignore the codebook information. Therefore, the compress-and-forward strategy is kind of optimal in this sense, under the random coding framework.
454

On Wireless Sensor Networks with Arbitary Correlated Sources

Mahboubi, Seyyed Hassan January 2008 (has links)
An achievable rate region for general wireless sensor networks is proposed. A general multi-source, multi-relay, multi-destination wireless sensor network with arbitrarily correlated sources is considered. Each node can sense some real phenomena and send its readings to one or more sinks (data gathering nodes) via some relays. It also can relay some correlated or independent readings of other nodes, simultaneously. In this problem the source and channel coding separation is not optimal and the information which each reading has about others nodes is destroyed in separation. Thus, a joint source channel coding scheme can be used. The problem consists of relay channels and multiple access channels with arbitrarily correlated sources. The proposed scheme is based on regular block Markov encoding/backward decoding and code division multiple-access (CDMA) and the result is a combination of multi-relay and multiple-access with correlated sources.
455

The Effect of State Capacity on Democratic Transition and the Survival of New Democracies

Kuthy, Daniel W 15 December 2011 (has links)
This dissertation investigates the effect of state capacity on the probability for democratic transition and the survival of democracies. I seek to answer these quesitons through the use of both quantitative and qualitative analysis. In my statistical models, I make use of Cox Proportional Hazard Models. These are supplemented by two case studies involving South Korea and the Philippines. My expectation, which is supported by the results presented in this study, is that higher levels of state capacity will make authoritarian regimes more stable and thus make democratic transitions less likely, but if democratic transitions take place, higher levels of state capacity will make new democratic regimes more likely to survive.
456

Lean on me: Informal social networks and the prevention of intimate partner violence in sexual minority communities

Lippy, Caroline A. 30 June 2011 (has links)
Research finds that intimate partner violence (IPV) occurs at comparable rates for heterosexuals and sexual minorities; however, few IPV prevention programs exist for sexual minority communities. Most programs are developed on heterosexuals and ignore the unique contexts and dynamics of IPV for sexual minorities. Community capacity IPV prevention programs aim to increase the skills and resources within informal social networks, and they represent a promising approach to IPV prevention for sexual minority communities. The current study explores the informal networks of sexual minorities in order to build knowledge that can inform the future development of community capacity IPV prevention programs for sexual minorities. The goal of the current study was to provide information on three major aspects of sexual minorities’ informal networks: network structure, network function, and the use of networks by sexual minorities experiencing IPV. The study used a mixed method design. The quantitative component included an online survey completed by 367 sexual minorities. The survey asked with whom sexual minorities discuss their intimate relationships, and it asked the response and helpfulness of each member. These data illustrated the structure and function of informal networks. The study also included interviews with seven sexual minority women on their experiences of seeking help for IPV from their social networks. This information addressed the third aspect of informal networks. The quantitative results revealed that sexual minorities turn to on average only three people to discuss relationship issues. Surprisingly, a substantial number were family, and almost half were heterosexual. The qualitative results illustrated that many informal networks members could benefit from receiving education on sexual minority identities and issues, IPV in sexual minority communities, and communication skills. The findings illustrated key aspects of informal networks that can be used to inform future community capacity IPV prevention programs for sexual minorities. Specifically, the quantitative data on network structure and function can be used to inform relevant targets for future programs, and the data from the interviews can inform aspects of program curricula.
457

Spetsbärförmåga hos betongpålar slagna i friktionsjord

Elvin, Lena, Dangré, Markus January 2004 (has links)
The purpose of this study was to build a database for point-bearing piles in dense noncohesive soil, predominantly moraine. Further, the database was analysed and areas with difficult geotechnical conditions was identified. The database includes for point-bearing piles driven to refusal in moraine. Piles with mainly shaft friction have been excluded. Only concrete piles have been included. Geographically the database covers almost all geotechnical conditions of Sweden. The total amount of piling projects is 110 and the total amount of piles is 600. For contractors, foundation work is usually connected with a lot of uncertainty and risk, concerning the estimating of time and cost. During the design stage of foundation construction the database can be a useful tool to estimate suitable loads on the piles. The data was analysed further with different statistical method. Possible reasons for low bearing capacity, in some projects, have also been investigated. / Syftet med examensarbetet är att upprätta en databas över spetsburna pålar fastslagna i friktionsjord och morän. Vidare skall databasen analyseras för att hitta styrande parametrar samt även hitta områden med problematisk geoteknik. Databasen omfattar spetsburna pålar som stoppslås i friktionsjord. Pålar som i huvudsak är mantelburna har uteslutits. Endast betongpålar har tagits med. Geografiskt omfattar databasen i stort sett hela Sverige. Totalt innehåller databasen 110 projekt med sammanlagt över 600 pålar. För entreprenörer i byggbranschen är grundläggningsarbetet ofta förknippat med ekonomiska risker och osäkerhet gällande omfattning och tidsåtgång. Vid dimensionering av grundläggningsarbeten kan databasen vara till stor hjälp för att bestämma lämpliga lastnivåer. Mängden slagningsarbete och risken för bortslagna pålar kan lättare uppskattas. Först analyserades olika påltyper utan ytterligare urvalskriterier. Vikten av att filtrera informationen blev då tydlig, eftersom resultatet blev svårtolkat och inga markanta samband kunde urskiljas. Med databasen som grund har materialet vidare analyserats med hjälp av statistiska metoder. Orsaken till låga bärförmågor vid ett urval av projekt har även kartlagts.
458

Network Capacity, Coverage Estimation and Frequency Planning of 3GPP Long Term Evolution

Zhang, Liang January 2010 (has links)
The recent increase of mobile data usage and emergence of new applications such as Online Gaming, mobile TV, Web 2.0, Streaming Contents have greatly motivated the 3rd Generation Partnership Project (3GPP) to work on the Long Term Evolution (LTE). The LTE is the latest standard in the mobile network technology tree. It inherits and develops the GSM/EDGE and UMTS/HSPA network technologies and is a step toward the 4th generation (4G) of radio technologies designed to optimize the capacity and speed of 3G mobile communication networks. In this thesis, the LTE system capacity and coverage are investigated and a model is proposed on the base of the Release 8 of 3GPP LTE standards. After that, the frequency planning of LTE is also studied. The results cover the interference limited coverage calculation, the traffic capacity calculation and radio frequency assignment. The implementation is achieved on the WRAP software platform for the LTE Radio Planning.
459

To Use the Codebook Information or Not: A Study of the Compress-and-Forward Relay Strategy

Wu, Xiugang January 2009 (has links)
The motivation of this thesis is to understand how nodes can cooperate in a particular relay channel, say a relay channel with orthogonal link between relay and destination. We are especially interested in the scenario where relay cannot decode the message sent because the coding rate is too large vis-a-vis what it can handle, and try to investigate the optimality of compress-and-forward strategy for this scenario. Specifically, noting that relay's compression is based on the unconditional distribution of its observation, it is natural to ask if relay can do better if it utilizes the source's codebook information, such that the performance of the relay network is improved? To answer this key question, we need to find the posterior Conditional Distribution of channel Output given Codebook Information (namely CDOCI) for the channel between source and relay. Firstly, we model it as Binary Symmetric Channel (BSC) and show that under the now standard random coding framework, if the input distribution is uniform, then with high probability, the CDOCI is asymptotically uniform when coding rate is greater than the channel capacity and the block length is sufficiently large. Then it is shown that under the discrete memoryless channel (DMC), for those strongly typical output sequences, with high probability, the CDOCI is also asymptotically uniform and close to the unconditional distribution, for rate above capacity and sufficiently large block length. These results implicate that relay can hardly do better with codebook information used. To confirm this implication, we show that for sufficiently large block length, the rate needed for relay to forward its observation when the codebook information is utilized approaches the rate needed when the relay simply ignore the codebook information, if the coding rate at source is larger than channel capacity. Now the answer to the above key question is apparent: in the cases of BSC and DMC, even if the relay tries to utilize the information obtained by knowing the codebook used at the source, it can hardly do better than simply ignore the codebook information. Therefore, the compress-and-forward strategy is kind of optimal in this sense, under the random coding framework.
460

On Wireless Sensor Networks with Arbitary Correlated Sources

Mahboubi, Seyyed Hassan January 2008 (has links)
An achievable rate region for general wireless sensor networks is proposed. A general multi-source, multi-relay, multi-destination wireless sensor network with arbitrarily correlated sources is considered. Each node can sense some real phenomena and send its readings to one or more sinks (data gathering nodes) via some relays. It also can relay some correlated or independent readings of other nodes, simultaneously. In this problem the source and channel coding separation is not optimal and the information which each reading has about others nodes is destroyed in separation. Thus, a joint source channel coding scheme can be used. The problem consists of relay channels and multiple access channels with arbitrarily correlated sources. The proposed scheme is based on regular block Markov encoding/backward decoding and code division multiple-access (CDMA) and the result is a combination of multi-relay and multiple-access with correlated sources.

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