• Journal of the Korean Data and Information Science Society
• /
• v.24 no.3
• /
• pp.651-658
• /
• 2013

For the marginal model and generalized estimating equations (GEE) method there is important full covariates conditional mean (FCCM) assumption which is pointed out by Pepe and Anderson (1994). With longitudinal data with time-varying stochastic covariates, this assumption may not necessarily hold. If this assumption is violated, the biased estimates of regression coefficients may result. But if a diagonal working correlation matrix is used, irrespective of whether the assumption is violated, the resulting estimates are (nearly) unbiased (Pan et al., 2000).The quadratic inference functions (QIF) method proposed by Qu et al. (2000) is the method based on generalized method of moment (GMM) using GEE. The QIF yields a substantial improvement in efficiency for the estimator of ${\beta}$ when the working correlation is misspecified, and equal efficiency to the GEE when the working correlation is correct (Qu et al., 2000).In this paper, we interest in whether the QIF can improve the results of the GEE method in the case of FCCM is violated. We show that the QIF with exchangeable and AR(1) working correlation matrix cannot be consistent and asymptotically normal in this case. Also it may not be efficient than GEE with independence working correlation. Our simulation studies verify the result.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.11
• /
• pp.1285-1296
• /
• 2015

As examples of the region's transition to quasi-public goods a previous stage of full public goods also extremely limited in research. However, in this way can it compensate for this paper as a system to minimize moral hazard by electronic information and communication systems focused on safety in accordance with the methods and gave public goods introduction of grafting of electronic information systems played the Yeosu area to specific cases I went to the deployment.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.3
• /
• pp.644-652
• /
• 2016

This paper presents an improved single-stage ac-dc LED-drive flyback converter using the transformer-coupled lossless (TCL) snubber. The proposed converter is derived from the integration of a full-bridge diode rectifier and a conventional flyback converter with a simple TCL snubber. The TCL snubber circuit is composed of only two diodes, a capacitor, and a transformer-coupled auxiliary winding. The TCL snubber limits the surge voltage of the switch and regenerates the energy stored in the leakage inductance of the transformer. Also, the switch of the proposed converter is turned on at a minimum voltage using a formed resonant circuit. Thus, the proposed converter achieves high efficiency. The proposed converter utilizes only one general power factor correction (PFC) control IC as its controller and performs both PFC and output power regulation, simultaneously. Therefore, the proposed converter provides a simple structure and an economic implementation and achieves a high power factor without the need for any separate PFC circuit. In this paper, the operational principle of the proposed converter is explained in detail and the design guideline of the proposed converter is briefly shown. Experimental results for a 40-W prototype are shown to validate the performance of the proposed converter.

• Journal of Korean Society for Geospatial Information Science
• /
• v.12 no.3 s.30
• /
• pp.43-50
• /
• 2004

This study has an object of searching for appropriateness in applying the trip distribution model by studying the changes of the character of parameter which the model contains and by analyzing and evaluating trip distribution technique out of few steps of pre-estimate technique for the traffic demand through computer simulation centering around Kwangju. Method of this study is investigating the basic theory for trip distribution model and with this grounding, I rearranged it as research data for trip distribution model compatible for Kwangju, using data such as research data on actual state, the statistics annual report and basic plan for traffic full equipment of Kwangju. So, The most stable measure of the type of trip distribution of Kwangju city was produced in Fratar and Detroit model, however, gravity model has a little bit low reliance in sharing of estimation and actual survey although it is astringent in short period.

• International Journal of Contents
• /
• v.6 no.3
• /
• pp.65-70
• /
• 2010

This paper addresses the importance of knowledge management (KM) and the relationship of that theory when applied to improving interior design organizational performance in four areas: people, processes, design products, and organizational performance. Included is the way knowledge theory manifests in three different professional settings: coaching and training, designing, and service settings. Knowledge management, although well established in interior design services, requires effort in coaching and training as motivation is a critical variable. Whereas, strategies for knowledge management vary from industry to industry given diversity in situational variables, knowledge in each professional setting can be significantly aided by capturing and storing empirical, tacit, and explicit information, providing real-time electronic storage and retrieval of information [5] and consistent with transformational theory, through opening communication channels across the full range of the organization, inspiring and motivating individuals, and aligning all members of the organization toward a common vision [8]. Professional settings discussed in this paper are:(a)an learning organization enumerated in KM; (b)designing factors for managing knowledge theory themes; and (c)service, effective, efficient, and innovative KM application that is relevant to the process of developing effective KM for interior design service organizations. Folded within each will be a discussion on KM's impacts on visions, strategies, costs, and organizational performance. It has reiterated the impact of KM on one level might lead to synergistic impacts on another. Thus, KM has the potential to produce several interconnected impacts on people, design products, processes, and organizations.

• Journal of Contemporary Eastern Asia
• /
• v.14 no.2
• /
• pp.5-15
• /
• 2015

A growing number of studies have examined the relevance and impact of social media in building organizational resilience, which the ability to recover from a crisis, in the field of emergency management. However, few studies have assessed how these emergency response organizations perceive their own use of social media in crisis situations. In attempting to fill this gap, this study conducted a structured survey with emergency-response organization representatives in Seoul, South Korea, to examine how such organizations evaluate their utilization of social media in an urban emergency situation and how their social media uses are related to promoting organizational resilience during adverse events such as a flood. Overall, the findings imply that organizations are not yet taking full advantage of social media. Respondent evaluations of their own social media use in all three assessment areas-information provision, information dissemination, and emotional messages-were not satisfactory. However, their perceptions of how well they utilize social media were positively related to how they view their organizational resilience. Therefore, it may be that these organizations realize the powerful role of social media in building organizational resilience but lack the knowledge and experience to make the best use of social media services.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.3
• /
• pp.561-569
• /
• 2005

Recently, the object-oriented design is the major paradigm for software development. Most systems are following this paradigm, but the past studies for a video conversation domain were not based on full-scale object-oriented design. Thus, this paper presents an systematical architecture design using UML for a video conversation system that is well-known and has high rate of usefulness. It analysis a video conversation system that has much demand of service as systematical functional/non-functional requirements, and the object-oriented design applying '4+1 View Model' guarantees the reusability of a component and makes it possible to extend a system by adding components as needed. Consequently, it is expected that the components of video conversation system designed by this paper will be useful the other video conversation systems and will be expanded to web environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.10a
• /
• pp.211-214
• /
• 2003

The problem of unsolicited e-mail has been increasing for years, so many researchers has studied about spam filtering and prevention. In this article, we proposed a faster spam prevention algorithm based on userID instead of full email address. But there are 2% of false-negatives by userID. In this case, we store those domains in a DB and filter them out. The proposed algorithm requires small DB and 3.7 times faster than the e-mail address comparison algorithm. We implemented this algorithm using SPRSW(Spam Prevention using Replay Secrete Words) to register userID automatically in userID DB.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.8
• /
• pp.1917-1924
• /
• 2015

Efficient routing algorithm is required to transmit data from source to destination by multi-hop transmission in wireless sensor networks. In the multi-hop transmission, multipath routing can be one of the solutions to cope with the traffic congestion and unstable link condition. In this paper, we propose partial multipath routing which does not establish a secondary full routing path but a partial multipath to complement some poor links, and it can enable stable data transmission and reduce the number of nodes in routing path and the required total power compared with conventional multipath routing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.149-153
• /
• 2012

The common process of full 5 three infantile department of pedagogy nurtures of 2012 department of pedagogy department is world process. For the early rising department of pedagogy originality education of the national talented man it uses the educational robot. The research is necessary in about development and production of the world process educational robot which equips a duplex link structure. Development it produces the world process educational insect robot which equips a link structure from the present paper. The present paper research it leads and early rising department of pedagogy originality education of the national talented man leads and will contribute in the national competitive power improvement which a national education development and the robot renovation of the nation leads.