• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 104
  • 23
  • 20
  • 16
  • 10
  • 8
  • 8
  • 5
  • 5
  • 4
  • 1
  • 1
  • 1
  • Tagged with
  • 236
  • 236
  • 75
  • 35
  • 32
  • 30
  • 26
  • 26
  • 24
  • 24
  • 23
  • 22
  • 22
  • 19
  • 19
  • 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.
11

Being Small and Managing Communities : An explorative study on how SMEs utilize community management to communicate

Linte, Thibault, Hervier, Ariane, Bogdan, Vincent January 2012 (has links)
Research on community management conducted in the past has used primarily examples and case studies within large corporations. Small and medium sized enterprises (SMEs) also need to be included in community management, exploring the ways in which they deal with community management and if the large company theories on the subject can be applied to them. In an attempt to respond to this gap in community management we respond to the question of how do small and medium-sized companies utilize communities to communicate successfully to their consumers? During our work, we noted that SMEs were facing two phases when dealing with community management. A strategic step, where the company has to define its goals, its targets, the means it will invest and the tools it will use to deal with community management. The second phase being an operational step includes the creation of communities and the management of them. In the strategic step, we pointed out questions which companies have to address before starting community management including the benefits that the company expects from the community, the amount it will invest in it and the tools the company will use. In the operational step, five main principles were highlighted as commonly used by SMEs to communicate through communities: (1) promotion of an Ideal, (2) uniting around shared interests, (3) the use of the myth as a gathering factor, (4) the importance of the community involvement in the company, and (5) the physical interaction between community members and the brand. Additionally, we found that SMEs have two main advantages when it comes to collaborating with customers/fans that large businesses did not have: proximity and flexibility. However, we found that it was difficult for small companies to find competent people working in the community management field. This lack of knowledge within SMEs appeared to be the primary reason why most brand communities failed. Therefore, in this thesis we aimed to point out good habits in terms of community management in order for SMEs to possess a basic knowledge, thus enabling them to benefit from their advantages of proximity and flexibility, which are a result of by their size and is essential for community management.
12

Effects of Constrained Aging on the Shape Memory Response of Nickel Rich Niti Shape Memory Alloys

Barrie, Fatmata Haja 2009 December 1900 (has links)
Ni50.6Ti49.4 single and Ni52Ti48 polycrystalline shape memory alloy samples were subjected to aging under a uniaxial stress, to form a single Ni4Ti3 precipitate variant and to investigate the effects of single versus multi-variant coherent precipitates on the shape memory characteristics including two-way shape memory effect (TWSME). Shape memory and superelasticity properties along with the effects of stress and temperature on the transformation temperatures, strain, hysteresis, dimensional stability, and R-phase formation were investigated. This was accomplished through the use of isobaric thermal cycling and superelasticity experiments and various microscopy techniques that included transmission electron microscopy (TEM), scanning electron microscopy, and optical microcopy. The results showed that it is feasible to use constrained aging to bias R-phase martensite variants upon cooling from austenite without any external stress, however, accomplishing this with B19’martensite was much harder as complete TWSME was only found in the Ni50.6Ti49.4 single crystalline sample oriented along the [112] direction. The onset of irrecoverable strain corresponded to the R-phase temperature hysteresis increase in the single crystalline samples regardless of the aging conditions. Through TEM analysis it was discovered that [112] and [114] twins were found in austenite due to plastic deformation of martensite during the superelasticity experiments. Since [112] twins are theoretically impossible to form in austenite, and since martensite was plastically deformed, [112] austenite twins were attributed to the transformation of compound twins in martensite, in particular [113] martensite twins formed during the plastic deformation of martensite, into austenite twins. In the Ni52Ti48 polycrystalline samples, a compressive R-phase variant was biased through constrained aging under 100 and 200 MPa uniaxial tensile stresses at 400°C and 450°C. Aging, in all conditions, produced a high density of Ni4Ti3 precipitates that was most likely responsible for the small transformation strain observed, less that 2%, upon transformation to martensite. In the future, samples with compositions between 50.8 and 51.5 Ni atomic percent, in addition to altered solution and aging heat treatments as compared to those used in this study should be investigated as it is believed that samples with these compositions will yield better and consistent TWSME responses through constrained aging.
13

Gaussian Two-Way Channel with Constellation-based Input

Banijamali, Seyedershad January 2013 (has links)
Achieving a higher transmission rate had always been a goal in the field of communications. Having a two-way channel in which two nodes transmit and receive data at the same time, is an important tool to achieve this goal. A two-way channel is the first step from point-to-point communication channel toward multi-user networks. In its ideal form, we can transmit data two times faster by using a perfect two-way channel. However, the area of two-way channels had not been of interest of researchers during the past years and number of articles on this area is considerably low comparing to other types of multi-user communication networks, such as multiple-access channel, broadcast channel and interference channel. On the other hand, use of analog-to-digital converters (ADC) is a must in modern systems to enable us to analyze data faster; nevertheless, presence of ADC add some other difficulties to the system. In this thesis, different scenarios about two-way channel are studied. The Shannon's model of two-way channel and his inner and outer bounds on the capacity of this channel are presented. For the Gaussian Two-Way Channel with quantized output, in which the ambient noise has a Gaussian distribution, the expression of Shannon's inner bound for both Gaussian and discrete inputs are derived. The best uniform quantizer to obtain the maximum achievable rate for Gaussian input is found numerically. Then we will evaluate the additive noise model for the quantizer from an information theoretic point of view. For the discrete input, the method of rotating one input with respect to other one is employed to enlarge the achievable rate region. At last, two scenarios will be studied in which, minimizing the power of interference, does not necessarily maximizes the transmission rate.
14

Hardware Prototyping of Two-Way Relay Systems

Wu, Qiong 2012 August 1900 (has links)
In this thesis, I conduct the hardware prototyping of a two-way relay system using the National Instruments FlexRIO hardware platform. First of all, I develop several practical mechanisms to solve the critical synchronization issues of the systems, including Orthogonal Frequency-Division Multiplexing (OFDM) frame synchronization at the receiver, source to source node synchronization, and handshaking between the sources and relay nodes. Those synchronization methods control the behavior of the two source nodes and the relay node, which play critical roles in the two-way relay systems. Secondly, I develop a pilot-based channel estimation scheme and validate it by showing the successful self-interference cancellation for the two-way relay systems. In particular, I experiment the self-interference cancellation technique by using several channel estimation schemes to estimate both source to relay channels and relay to source channels. Moreover, I implement the physical layer of a 5 MHz OFDM scheme for the two-way relay system. Both the transmitter and receiver are designed to mimic the Long Term Evolution (LTE) downlink scenario. The physical layer of the transmitter has been implemented in Field-Programmable Gate Arrays (FPGAs) and executed on the hardware board, which provides high throughput and fundamental building blocks for the two-way relay system. The physical layer of receiver is implemented in the real-time controller, which provides the ?exibility to rapidly recon?gure the system. Finally, I demonstrate that the 5MHz OFDM based two-way relay system can achieve reliable communications, when the channel estimation and system synchronization can be correctly executed.
15

EXPLORING MESH NETWORKS WITH INET RADIOS

Newton, Todd A., Timme, M. Wayne, Abbott, Ben A. 11 1900 (has links)
The integrated Network Enhanced Telemetry (iNET) radios provide a two-way telemetry link that interconnects the airborne instrumentation system with ground-based systems. This capability brings the flight test telemetry domain into the realm of the more classic mesh networks in a mobile ad-hoc environment. The underlying radio frequency (RF) communication protocols defined in the iNET standards support a variety of classic networking protocols. The scheduling algorithms between Link Managers and radios can operate as a collision network, like classic Ethernet. This paper describes the communication protocols and scheduling algorithms of the iNET radios, and it provides results of their use in a self-scheduling algorithm such as a classical token ring network.
16

Physical-Layer Network Coding for MIMO Systems

Xu, Ning 05 1900 (has links)
The future wireless communication systems are required to meet the growing demands of reliability, bandwidth capacity, and mobility. However, as corruptions such as fading effects, thermal noise, are present in the channel, the occurrence of errors is unavoidable. Motivated by this, the work in this dissertation attempts to improve the system performance by way of exploiting schemes which statistically reduce the error rate, and in turn boost the system throughput. The network can be studied using a simplified model, the two-way relay channel, where two parties exchange messages via the assistance of a relay in between. In such scenarios, this dissertation performs theoretical analysis of the system, and derives closed-form and upper bound expressions of the error probability. These theoretical measurements are potentially helpful references for the practical system design. Additionally, several novel transmission methods including block relaying, permutation modulations for the physical-layer network coding, are proposed and discussed. Numerical simulation results are presented to support the validity of the conclusions.
17

Pasivní kmitočtové výhybky pro dvoupásmové reproduktorové soustavy / Passive Frequency Crossover for Two-Way Loudspeaker Systems

Vydarený, Ján January 2020 (has links)
-
18

An Examination of Nonverbal Cues Used By University Professors When Delivering Instruction in a Two-Way Video Classroom

Anderson, Myron R. 10 December 2001 (has links)
As the education field further embraces technology and the classroom develops a distance component, more and more colleges and universities are delivering classes via two-way video. Research has established that nonverbal cues exist and play a significant role in classroom instruction (Arnold & Roach, 1989; Cyrs, Conway, Shonk, & Jones, 1997; Rosenthal & Jacobson, 1968). The growing popularity of two-way video and the fundamental concepts of communication, establishes a parallel between traditional classroom and two-way video instruction delivery. This parallel and the established effect that nonverbal cues have on instructional delivery support the need to study nonverbal communication in a two-way video classroom. Descriptive observation of six instructors, each teaching five 50-minute lectures, produced the data for this preliminary study. The nonverbal cues were recorded using the Two-way Video Nonverbal Cue Observation Instrument (TV-NCOI). The TV-NCOI consisted of seven nonverbal communication categories and 22 variables used to identify and quantify professor's nonverbal cue use in two-way video instructional delivery. Frequency response, common themes, and nonverbal cue delivery observations, collected by the TV-NCOI, were used to answer the research questions; what nonverbal cues are used by university professors when delivering instruction in a two-way video classroom? The results suggest that professors in engineering and chemistry, the two focused disciplines, heavily used nonverbal cues when delivering instruction in a two-way video classroom. However, the majority of these cues have a technical delivery base. The traditional classroom nonverbal cues of board pointing, material pointing, and accent gestures are delivered via computer cursor, two-way video camera, and software applications in the two-way video classroom. More specifically, 87% on the nonverbal cues used in instructional delivery had a technological connection and only 13% of the nonverbal cues used were without a technical delivery base. / Ph. D.
19

A Comparative Analysis of Reading and Math Assessment Scores of Students Attending Three Traditional Elementary Public Schools and Three Elementary Charter Schools In Virginia

Brown, Renee Williams 06 June 2023 (has links)
Advocates of privatizing education suggest that traditional public schools are not adequately preparing students for college, career readiness, and global citizenship (Lobosco, 2019; Schneider and Berkshire, 2020; Tienken and Mullen, 2016). Charter school supporters believe charter school students perform better than public school children on state standardized tests (Lubienski and Lubienski, 2014). Advocates for traditional public schools promote the idea that there are no significant differences between public and charter schools in academic achievement (Chen, 2020b; Fischler, 2021). This study compares public and charter elementary school students in terms of their reading and math assessment scores, both as measured by the Virginia Standard of Learning (SOL) for the 2018-2019 school year. Data were collected and analyzed on 642 students enrolled in three of Virginia's elementary charter schools and three traditional public schools in Loudoun County and Richmond City. SOL assessment data for the public and charter schools were compared for the overall student population per grade level to determine if there is a significant difference for the 2018-2019 school year. A two-way ANOVA was utilized in this study. Results indicated no significant differences in the reading mean SOL assessment scores between traditional public elementary and public charter school students: F (1, 636) = .119, p = .730. Additionally, results showed no significant interaction between school type and grade level between traditional public elementary and public charter schools: F (2, 636) = 1.076, p = .342. However, findings revealed a significant difference in the reading SOL assessment scores between grade levels of traditional public elementary schools and public charter schools: F (2, 636) = 4.473, p = .012. Furthermore, results from the math analysis indicated no statistical differences in math SOL scores between traditional public elementary schools and public charter schools: F (1, 636) = .000, p = .997. Also, findings indicated no significant difference in the math SOL scores between the grade levels of traditional public elementary and public charter schools: F (2, 636) = .520, p = .595. / Doctor of Education / Advocates of privatizing education suggest that traditional public "brick-and-mortar" schools are not adequately preparing students for college, career readiness, and global citizenship (Lobosco, 2019; Tienken and Mullen, 2016; Schneider and Berkshire, 2020). Charter school supporters believe charter school students perform better than public school children on state standardized tests (Lubienski and Lubienski, 2014). Advocates for traditional public schools promote the idea that there are no significant differences between public and charter schools in academic achievement (Chen, 2020b; Fischler, 2021). This study compares public and charter elementary school students in terms of their reading and math assessment scores, both as measured by the Virginia Standard of Learning (SOL) for the 2018-2019 school year. Data were collected and analyzed on 642 students enrolled in three of Virginia's elementary charter schools and three traditional public schools in Loudoun County and Richmond City. SOL assessment data for the public and charter schools were compared for the overall student population per grade level to determine if there is a significant difference for the 2018-2019 school year. This study did not reveal any significant differences in reading and math SOL scores between traditional elementary public schools and public elementary charter schools. However, findings in this study revealed significant differences in reading SOL scores on average among grade levels. Conversely, findings did not reveal any differences in math SOL assessment scores on average between grade levels of traditional public elementary school and public elementary charter school students.
20

Is two-way immersion education associated with social and intercultural benefits? A peace-linguistic examination of Staatliche Europa-Schule Berlin

Meier, Gabriela Sylvia January 2009 (has links)
This thesis is situated in the field of applied linguistics, education and European Studies. The empirical part examines outcomes in a two-way immersion (TWI) education model in Berlin (SESB) that go beyond linguistic or academic achievements. Based on a peace-linguistic framework established for the purpose of this study, this thesis assesses to what extent SESB programmes are associated with dimensions related to peace education, social capital and critical applied linguistics. Additionally, a teacher survey looks at attitudes towards bilingual and monolingual education and social integration. The findings are discussed in the framework of previous studies, chiefly from the USA, and in terms of language policy development in Germany and in Europe. This leads to a number of recommendations for stakeholders and policymakers. Employing a quasi-experimental design, involving a TWI and a control group, data were collected through a questionnaire survey of 14-18 year-old students (N=603) and teachers (N=32) in Berlin, which were analysed using primarily quantitative methods (including multiple regression) but with some qualitative elements. Based on statistically significant effects with at least small effect sizes, it was established that students in SESB had a greater sense of inclusion among classmates and greater conflict resolution skills than the control group. When looking at effects in subgroups (students with German, bilingual or non-German language backgrounds) there were also positive effects, however, the groups were affected in different ways, as is set out in this thesis. Furthermore, SESB also had a positive effect on relationships between parents and teachers, as well as on the students’ language attitudes and use patterns. In conclusion, it is argued that, besides personal and societal multilingualism, TWI programmes in Berlin are associated with greater potential for cohesion in the school class, and may benefit wider social integration of different language communities. Additionally, this thesis introduces German TWI programmes to an English-language audience.

Page generated in 0.0385 seconds