• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10B
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• pp.899-915
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• 2003

Delivering rich and continuous media contents robustly over a wide range of network conditions of the wired/wireless Internet is a highly challenging task. To address this challenges, the continuous media applications at the edge of network has become more and more adaptive while the best-effort Internet is slowly progressing towards improved networking services. That is, the role of network adaptive media delivery, which dynamically links the quality demand of application contents to the underlying networking services, has become more crucial. In this paper, we will first review the required network adaptation functionalities seen from the application side: congestion control / rate control, error control, and synchronization / adaptive playout. Then, we start the coverage of networking support issues that helps the realization of network adaptive media streaming - from network support and protocol support toward consolidated support via middleware. Finally, we propose a dynamic network adaptation framework that efficiently leverages its awareness of both media application (including contents) and underlying networking support.

• Asia pacific journal of information systems
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• v.18 no.2
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• pp.73-94
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• 2008

When individuals collaborated in virtual settings, communication is medicated through a variety of communication technologies, and is associated not only with communication effectiveness but also with socio-emotional interactions among group members. In this regards, scholars have examined how technology-mediated communication systems can be designed and used to facilitated communication interaction. However, the empirical results of the previous studies have revealed inconsistencies in the effects of communication media on users' behavioral or attitudinal responses, and on their viable effectiveness in organizations. Some studies claim that computer-mediated communication(CMC) is task-oriented but not suitable for emotional expression since it hinders close interpersonal interaction. On the other hand, some studies argue that individuals are able to develop interpersonal relationships more effectively in a CMC environment than in an FtF-environment. Due to the different perspectives, a theoretical gap exists, and it leads to the inconsistent research findings. The purpose of this paper is to combine the two different perspectives into single unified model, thereby providing a more realistic and comprehensive understanding about virtual collaboration. The present study here sought to answers the following questions with organizational communication perspective: What are the major components of virtual collaboration? What factors affect the performance of virtual collaboration? And what kind of managerial efforts should organization make in order to facilitate CMC media effectiveness in virtual collaboration? Although there is a certain belief that new media, namely technology-mediated communication support would create new opportunities, the problem of "how" or "why" has been an important question that is still not fully addressed. In this regards, we collectively reexamined previous literatures with major issues which are still controversial and integrated various theoretical activity within computer-mediated communication domain: task-oriented approach, socio-emotional approach, and evolutionary psychological approach. Our first contribution is to develop a framework for virtual collaboration by combining two different perspectives into a single unified model, providing a more realistic and comprehensive understanding. The second main contribution is the joint modeling of both social presence and cognitive effort, and the effects on two distinct but important communication outcomes(i.e., take performance and relational development). We tested the research hypotheses which were developed based on the various CMC theories using data gathered through a self-administered mail survey of 127 individuals of 69 virtual workgroups. The proposed model was supported, providing preliminary evidence that the tension between two opposite view should be integrated. The results show that the individual's psychological processes(social presence and cognitive effort) in a virtual environment significantly mediated the effect of CMC inputs (media richness, user adaptation, and shared contest) on the CMC outputs (task performance and relational development). Furthermore, this study shows that the lack of perceived media richness of CMC media can be complemented by user adaptation and shared context. Based on the results, we discuss how communication system should be designed and implemented so as to promote virtual interaction as well as how a virtual workgroup should be composed to complement the lack of media richness. A virtual collaboration using CMC media may create new value by overcoming the logistical constraints. On the other hand, it may also generate various managerial risks such as communicational depersonalization, process dissatisfaction, and low cohesion. Therefore, this study suggests that organization managers should carefully choose the CMC mediums and monitor individual member's cognitive and affective psychological processes during virtual collaboration to reduce potential risks in virtual collaboration.

• Journal of the Ergonomics Society of Korea
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• v.32 no.1
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• pp.37-45
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• 2013

Objective: This study describes the change of operator performance in drastic change of illumination level, and proposes an alternative method to cope with it. Background: The control standard of illumination for nuclear power plants(NPPs) is based on the set of limit criteria for maintaining a specific illumination level. However, there is a possibility to cause human errors according to the psychological and physiological influences to operators in the situation of drastic change of illumination such as SBO(Station Black Out), so a basic study is necessary to review the current approach. Method: We assessed the visual fatigue, subjective work load and task performance according to the three illumination situations(Normal Illumination, Emergency Illumination, and Drastic Change of Illumination). Result: Research finding shows that there are not significant differences in task performance between normal illumination (1,000lx level) and emergency illumination (100lx level), only if beyond the dark adaptation limit. However, subjective work load on mental demand and visual fatigue show a potential challenge to visual performance in drastic change of illumination. Conclusion/Application: Several trials can complement this challenge in NPPs by applying 3-way communication, enhancing readability of procedures, and managing the visual factors affecting the operators' performance through a Visual Environment Management Program including visual health aspects, etc.

• Journal of Family Resource Management and Policy Review
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• v.11 no.3
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• pp.67-79
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• 2007

In this study, I examined the concept of action learning, its characteristics, operation method, and action learning cases in domestic and foreign countries. Also, I studied the possibility of using action learning in teaching healthy family specialist education. I researched the wellbeing action learning held from June 10 to June 20, 2007, with 20 participants. I conducted interviews and wrote a paper about how much action learning subjects were helped in their improving task-handling ability, its merits and drawbacks, and suggestions the subjects had about their participation in. The results were as shown below. First, the Catholic Welfare Department of Baekseok Uuniversity developed and operated action learning subjects to improve task-handling abilities in NURY business. Second, the action team valuated its subjects that everyone had fear and burden about action learning, but as time goes by, their confidence and adaptation ability have been improved. Also, organization staff and coaches answered that it was helpful to their self-development and improve capacity.

• Journal of the Korea Safety Management & Science
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• v.23 no.4
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• pp.11-21
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• 2021

In order to explore the job crafting experience of millennial safety workers, this study conducted a qualitative case research with five safety workers of S Energy from March 26 to September 27, 2021 . As a result of the analysis, task crafting showed 'matching one's strong suit with a given task', 'expanding work knowledge using social network service (SNS)', and 'making changes in job performance methods for preemptive safety management activities'. Also, Cognitive crafting showed 'recognition of social vocation as a safety job', 'recognition of a role to grow as a safety management expert', and 'cognitive changes from means of organizational adaptation to enjoyment and energy of life'. At the same time, in relation crafting, 'establishment of amicable relationships through SNS in non-face-to-face and rapid communicating situations', 'safety management made through with mutual cooperations between business people', and 'reborn as a mutual safety net in business relationships' appeared. These can be used as basic data to accumulate the theoretical basis for job crafting research of millennial safety workers and to improve their job satisfaction. A follow-up study was proposed for safety workers with occupations of various kinds.

• Journal of Korea Technology Innovation Society
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• v.10 no.4
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• pp.755-788
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• 2007

This study investigates the effects of individual and group level factors on the use of GSS (Group Support System) and task performance from GSS use. GSS facilitates the group work, so that GSS adoption is not necessarily influenced only by individual perceptions on information systems. Adaptive Structuration Theory (AST) in our study to explain the adoption and success from GSS use. AST contends that the success of IS is not necessarily the technical fit between tasks and technology, instead the political outcome among user socializations. We have the following two research inquires: Are the IS use and performance maximized when information technologies are provided properly?; and, Does TTF always influence positively on IS use (or performance)? To research these issues, we investigate the influence of TTF (Task-Technology Fit) on use and performance of GSS, which is introduced to foster collaboration among organizational members. Drawing insights from the AST, we examine if COA (Consensus on Appropriation) among group members and FOA (Faithfulness of Appropriation) between those who use technology and who design it show any moderating effect. A questionnaire survey was conducted on firms using the GSS for one month from June 2 to June 27 2005 and a sample of 303 responses was used for a statistical analysis. The result demonstrates that TTF exerts a positive influence on use and performance of GSS. We find that the stronger the COA, the greater the effect of W on use of GSS and performance. FOA likewise has a positive effect on both use of GSS and performance. The TTF model has been widely applied to studies on individual performance of information system, whereas the AST theory specifically explains members' adaptation process to information system. By integrating the AST theory with the TTF model, the study contributes to heightening our understanding on if and how individual performance varies with the use of GSS.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.300-303
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• 2003

An Algorithm based on direct implementation of variable structure systems theory approach is proposed for on-line training of multilayer perceptrons. Network structures which have multiple inputs, single output and one hidden layer are considered and the weights are assumed to have capabilities for continuous time adaptation. The zero level set of the network learning error is regarded as a sliding surface in the learning parameters space. A sliding mode trajectory can be brought on and reached in finite time on such a sliding manifold. Results from simulated on-line identification task for a two-link planar manipulator dynamics are also presented.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.8
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• pp.703-709
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• 2000

This paper proposes a compliance control strategy for the robot manipulators accidentally interact-ing with an unknown environment. In this proposed method each in the diagonal stiffness matrix corre-sponding to the task coordinate in a Cartesian space is adaptively adjusted during contact along the corresponding axis based on the contact force with its environment. This method can be used for both unconstrained and constrained motions without any switching mechanism which often causes undesirable instability and/or vibrational motion of the end-effector. The experimental results show the effectiveness of the proposed method by employing a two link direct drive manipulator interacting with an unknown environment.

• MALSORI
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• no.57
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• pp.165-174
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• 2006

In this paper we use a training algorithm, MCE (Minimum Classification Error), to improve the performance of a text-independent speaker identification system. The MCE training scheme takes account of possible competing speaker hypotheses and tries to reduce the probability of incorrect hypotheses. Experiments performed on a small set speaker identification task show that the discriminant training method using MCE can reduce identification errors by up to 54% over a baseline system trained using Bayesian adaptation to derive GMM (Gaussian Mixture Models) speaker models from a UBM (Universal Background Model).

• Structural Engineering and Mechanics
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• v.6 no.5
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• pp.473-484
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• 1998

The first and second moments of response variables for SDOF systems with hysteretic nonlinearity are obtained by a direct linearization procedure. This adaptation in the implementation of well-known statistical linearization methods, provides concise, model-independent linearization coefficients that are well-suited for numerical solution. The method may be applied to systems which incorporate any hysteresis model governed by a differential constitutive equation, and may be used for zero or non-zero mean random vibration. The implementation eliminates the effort of analytically deriving specific linearization coefficients for new hysteresis models. In doing so, the procedure of stochastic analysis is made independent from the task of physical modeling of hysteretic systems. In this study, systems with three different hysteresis models are analyzed under various zero and non-zero mean Gaussian White noise inputs. Results are shown to be in agreement with previous linearization studies and Monte Carlo Simulation.