• Journal of the Korean Statistical Society
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• v.33 no.4
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• pp.367-379
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• 2004

This article deals with the nonparametric analysis of longitudinal data when there exist possible correlations among repeated measurements for a given subject. We consider a quasi-likelihood regression model where a transformation of the regression function through a link function is linear in time-varying coefficients. We investigate the local polynomial approach to estimate the time-varying coefficients, and derive the asymptotic distribution of the estimators in this quasi-likelihood context. A real data set is analyzed as an illustrative example.

• Journal of the Korea Society of Computer and Information
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• v.23 no.5
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• pp.65-72
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• 2018

This study analyzes college dropout cases to reduce its rate. The analysis is preferentially carried out by figuring out our current situation of college dropout rate in pertinent cases and all around country's. Based on the current states, statistical analysis is accomplished as follows; analyzing the characteristic differences between the being in school's and the dropouts' by T-Test, determining the influence factor by logistic regression analysis and drawing the target group for special treatments through these statistical analysis. To reduce dropout rate, several measures could be adopted; focused counseling for each target group, special monitoring for students on leave of absence and opening major subjects for improving relationship between students and professors. The measures suggested by the analysis through this study are expected to lower the dropout rates effectively in college or specific fields including engineering science.

• International Journal of Contents
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• v.5 no.3
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• pp.57-64
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• 2009

Korea has relied on top down development method, in which companies, research and education institutions move into the industrial complexes established by the government. However, to improve local competitiveness, the paradigm is shifting from the government initiated industrial complex to the clusters based on the cooperative network of the region. Representative case is 'Samcheok-si Fire & Emergency industry cluster construction project' that begun in 2007. AHP technique analysis results on first-stage showed that priority was on policy and network elements, and the results of second-stage analysis show that priority was on Policy incentives to internationalize the cluster and strengthen link,. Cluster branding, Sharing of organizational culture to cope with changes in environment, Creation of group learning culture. The subject of this research is limited to Samcheok-si's the Fire and Emergency Industry cluster formation project. Therefore, the research area and standard should be expanded to increase generality in further researches.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.548-555
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• 1998

The influences of high speed train on the dynamic responses of steel composite railway bridges are investigated. The bridge system which has two Ⅰ-girder and several cross beams is modeled with plate and frame elements. With assumption of concrete slabs ate fully connected with steel girders, the offset between slabs and girders is modeled using rigid link. The track system is modeled using beams on elastic foundation theory. And, the TGV train is modeled in 2-dimension considering bouncing and pitching motion. And, braking action of vehicle is considered using speed dependent braking function. To investigate the behavior of bridges due to moving trains, parametric studies are performed.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.195-199
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• 2003

BEE 802.11 Wireless LAN protocol uses fixed transmission power. It does not consider a power control mechanism based on the distance between the transmitter and the receiver in order to improve overall channel utilization. In home environment, where stations generally lie around an AP, the AP is subject to use transmission power more than it needs. And wireless LAN stations may require different minimal desired received power. If there are many adjacent BSSs in densely populated WLAN area, they might cause RF interference to one another. In this paper we focus on the improvement of aggregate utilization by mitigating RF interference among BSSs. We show that RF interference by APs can be reduced by controlling transmission power using Link Margin information. The reduced interference will then lead to the increased aggregate throughput which is efficient resource utilization.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.7
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• pp.1833-1841
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• 1996

Recently, by emerging of the ALE techniques that make it possible to providereliable communications link automatically, high frequency communiation is newly used as emergency communication and back-up for satellite communications. ALE signal is transmitted in burst, and the received signal is subject to distortions by detrimental multipath fading channels. In the case of that channel, the performance of ALE system is highly dependent upon that of synchronization techniques. In this paper, M-ary FSK signals are detected by a bank of bandpass filter, which is implemented using recusive DFT(Discrete Fourier Transform). Also an acquisition and trancking algorithm are designed uisng parallel structure and early-late-gate methods respectively. Finally, we verify the performance ofthe proposed synchronization algorithm by the computer simulation.

• Research in Mathematical Education
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• v.12 no.3
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• pp.215-233
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• 2008

Deep comprehension of basic mathematical notions and concepts is a basic condition of a successful teaching. Some elements of algebraic thinking belong to the elementary school mathematics. The question "What stays the same and what changes?" link arithmetic problems with algebraic conception of variable. We have studied beliefs and comprehensions of future elementary school mathematics teachers on early algebra. Pre-service teachers from three academic pedagogical colleges deal with mathematical problems from the pre-algebra point of view, with the emphasis on changes and invariants. The idea is that the intensive use of non-formal algebra may help learners to construct a better understanding of fundamental ideas of arithmetic on the strong basis of algebraic thinking. In this article the study concerning arithmetic series is described. Considerable number of pre-service teachers moved from formulas to deep comprehension of the subject. Additionally, there are indications of ability to apply the conception of change and invariance in other mathematical and didactical contexts.

• Korea Journal of Hospital Management
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• v.4 no.2
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• pp.192-218
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• 1999

The purpose of this research is to suggest how to develop the internet homepage of the general hospital. The research was operated with 72 general hospitals which were titled 'general hospital' by subject in internet web search engine. The contents of general hospital homepage was studied by internet screen. On the other hand, It was surveyed for homepage operation by mail questionaire. The contents was mainly composed with (1) introduction of hospital (2) medical examination and the treatment-related information (3) the information & communication (4) the general medicare service, specialist & employee service. In order to operate homepage effectively, inquiry system, reservation system, consulting, information search, phone number, etc, web database shall be established inside of hospital homepage which will link compatible with computer database in hospital. Human resources employment & purchasing order system used by a enterprise shall be in consideration of adopting, since it has various merits in light of hospital management.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.380-382
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• 1993

In this paper, we derive a simple robust nonlinear control scheme for n-link robot manipulators subject to parameter uncertainty. By using the theory of variable structure system(VSS) and taking advantage of the important property of the robot dynamics, the stability of the derived control scheme is proved. This scheme utilizes the desired trajectory outputs, which can be calculated a priori, instead of the actual joint outputs in the nonlinear compensation controller. So the amount of on-line calculations is largely reduced, and as a result, this scheme can be implemented much more efficiently.

• Journal of Technology Innovation
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• v.7 no.2
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• pp.37-56
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• 1999

Technology has always been the force multiplier that influenced production and effected increase in the standard of living. The difficult choices involved in developing and implementing new technologies are recognized, but the right choice is rarely well defined and progress is often subject trial and error. The process of managing technologies to create wealth is called MOT. MOT is proposed as the central link for knowledge drawn from engineering, business, science, and corporate practice. One academic response to global competition is the creation of graduate program in MOT that have different academic and experience requirements. The purposes of this paper can be divided into two categories: how about the realities of MOT programs in Korea and what is the recommendation for universities to introduce this program.