• The Korean Journal of Applied Statistics
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• v.33 no.3
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• pp.229-238
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• 2020

The very first statistics department in Korean universities was founded in 1962, meaning it has been 57 years since Korean academia has regarded statistics as a wholly independent field of study. Dr. Junbo Kim was the first faculty member hired by Korea University's statistics department. He made a seminal contribution to the development and publication of statistics textbooks in those early years, and in 1971, spearheaded the efforts to found the Korean Statistical Society, serving as its first president. Naturally, Dr. Kim's significant contributions have laid the cornerstones for the advancement of statistics as an independent field of study in Korea. In this paper, I will explore two main subjects: one is the early history of the Korean Statistical Society with a special emphasis on Dr. Kim's contributions, and the other is an analytical overview his publications. Specifically, I will focus on Modern Statistics: A Synthesis of Statistics and Estimates』(Kim, 1954), and 『Inferential Statistics: An Introduction to Sample Survey and Experimental Design』(Kim, 1956).

• Journal of Korean Society of Steel Construction
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• v.19 no.1
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• pp.117-127
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• 2007

In this study, we evaluate the strength of steel box beam-to-column connections subjected to axial loads in steel frame piers. The T-connection strength was reduced due to the column axial force in the two-story pier structure. To examine this phenomenon, non-linear FEM analysis was carried out and the analytical procedure was verified by comparing it with experimental results. To clarify the effect of the axial force and major design parameters in connection with strength, influence of panel zone width-thickness ratio, sectional area, and axial force was investigated using FEM analysis. Also, the theoretical strength equations were suggested by stress distribution of panel zone. The strength of the T-connection was compared with one of the one-story pier structure connections. As a result, the strength evaluation equations are proposed in consideration of the panel zone width-thickness ratio and sectional area ratio for the T-connections.

• Journal of Korean Society of Steel Construction
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• v.20 no.6
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• pp.793-805
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• 2008

Recently, steel modular systems are developed and have been applied to the projects requiring fast construction such as military barracks and vertical expansion of school buildings. The existing modular system with standard module of ${6m\times3m}$ has a problem that many columns are duplicated in the module connection and the wall thickness increases. In this study, $12m{\times}3m$ module is proposed to solve this problem. Various types of beam-middle column connection which are essential for realizing the $12m{\times}3m$ module are proposed and their maximum load capacity and failure mode are analytically and experimentally evaluated. The comparison between analytical and experimental results shows that the maximum axial load and failure mode can be accurately estimated by finite element analysis. Some connection types which have higher failure load than the design load of the column, can be used as the beam-middle column connection detail of the $12m{\times}3m$ module.

• Journal of Internet Computing and Services
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• v.1 no.1
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• pp.35-46
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• 2000

One of the main chalenges in personal communication services (PCS) is to locate many mobile terminals that may move frequently from place to place. Such a system operation is called location management. Many network signaling traffic, and database queries are required to achieve such a task. Several strategies have been proposed to improve the efficiency of location management. These strategies use location register databases to store the current location on mobile terminals, and are vulnerable to failure of the location registers. In this paper, we propose a fault-tolerant pointer forwarding with distributed home location register (FT-RFDHLR) to tolerate the failure of location registers. The performance of the proposed method is evaluated by an analytical model, and is compared with thew pointer forwarding with the single home location register (PFSHLR), the pointer forwarding with distributed home location register (PFDHLR), Biaz's bypass forwarding strategy (BFS) and two-path forwarding strategy (TPFS).

• Journal of Korea Spatial Information System Society
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• v.7 no.3 s.15
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• pp.33-44
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• 2005

Recently, the weather has been influenced by the environmental pollution and the oil price has been risen because of the lack of resources. So, the weather and energy are influencing on not only enterprises or nations, but also individual daily life and economic activities very much. Because of these reasons, there are so many researches about management of solar radiation needed to develope solar energy as alternative energy. And many researchers are also interested in identifying the area according to changing characteristics of climate data. However, the researches have not developed how to apply the cluster analysis, retrieval and analytical results according to the characteristics of the area through data mining. In this paper, we design a data model of the data for storing and managing the climate data tested in twenty cities in the domestic area. And we provide the information according to the characteristics of the area after clustering the domestic climate data, using k-means clustering algorithm. And we suggest the way how to apply the department store and amusement park as an applied weather marketing. The proposed system is useful for constructing the database about the weather marketing and for providing the elements and analysis information.

• Progress in Superconductivity
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• v.7 no.2
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• pp.114-119
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• 2006

High critical current density, high n value, multiple faults endurances, and fast recovery characteristics of YBCO thin films are very attractive characteristics for developing resistive type superconducting fault current limiters. But due to the limited current and voltage ratings of one YBCO module, it is needed to construct series and parallel module connections for high capacity electric networks. Especially for distribution network, more than 30 units should be connected in series to meet voltage level. So in order to construct distribution-level superconducting fault current limiter, simultaneous quench in one YBCO thin films should be realized, and furthermore, quench should be occurred in all fault current limiting units equally to avoid local heating and failures. In this paper, we proposed optimum design of YBCO thin films for fault current limiting module and technical method using shunt resistor to achieve simultaneous quench between multi current limiting units. From the analytical and the experimental results, optimal current path and thickness of shunt material was determined for YBCO thin films and shunt resistor between modules was developed. Finally, 14 kV one phase resistive fault current limiter using multi YBCO thin films was constructed and it was possible to get satisfactory test results.

• Journal of Korean Society of Steel Construction
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• v.14 no.5 s.60
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• pp.603-612
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• 2002

Numerical analyses have been carried out in order to check the applicability of high-strength steel to a medium-sized steel bridge. Using the yield strength of steel, Average Daily Truck Traffic (ADTT), and fatigue grade of structural detail as analytical parameters, the minimum weight sections that satisfy the limit states of the AASHTO LRFD design specification were determined through an optimization scheme. Likewise, the effects of the number of girders and span length on the applicability of high-strength steel were evaluated. Results show that high-strength steel may be employed in the steel bridge, since steel weight decreases with increasing yield strength regardless of the fatigue effect. Nonetheless, appropriate countermeasures against fatigue should be determined since it is a major factor in the effective use of high-strength steel in steel bridges.

• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.629-639
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• 2004

A steel frame is one of the most commonly used structural systems due to its resistance to various types of applied loads. Many studies have been conducted to investigate the effects of several parameters, such as connection flexibility, the boundary condition of each support, and beam-to-column stiffness ratio, on the characteristic behavior of a frame. Based on the results of these studies, several design methods have been proposed. This research focused on the number of bolts on the rotational stiffness of a double-angle connection, and its effect on the story drift of a frame. To achieve these purposes, a simplified analytical model was proposed. Several experimental tests were also conducted to obtain the rotational connection stiffness of each double-angle connection.

• Journal of Korean Society of Steel Construction
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• v.10 no.2 s.35
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• pp.201-209
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• 1998

The presence of elevated temperature can alter significantly the structural response of fibre-reinforced laminated composites. A thermal environment causes degradation in both strength and constitutive properties, particularly in the case of fibre-reinforced polymeric composites. Furthermore, associated thermal expansion, either alone or in combination with mechanically induced deformation, can result in buckling, large deflections, and excessively high stress levels. Consequently, it is often imperative to consider environmental effects in the analysis and design of laminated systems. Exact analytical solutions of higher-order shear deformation theory is developed to study the thermal buckling of cross-ply and antisymmetric angle-ply rectangular plates. The buckling behavior of moderately thick cross-ply and antisymmetric angle-ply laminates that are simply supported and subject to a uniform temperature rise is analyzed. Numerical results are presented for fiber-reinforced laminates and show the effects of ply orientation, number of layers, plate thickness, and aspects ratio on the critical buckling temperature and compared with those obtained using the classical and first-order shear deformation theory.

• Journal of Technology Innovation
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• v.22 no.3
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• pp.193-223
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• 2014

Socio-technical systems are receiving growing attention as a core concept in the process of searching for proper solutions to sustainable growth. In this paper, we review the way for governing socio-technical transitions from a governmental perspective. Based upon the governance studies and transition research, we set social coordination and locus of transition pressures as transition contexts to differentiate transition policy governance. We propose four types of policy governance for sustainable socio-technical transitions: leading, facilitative, coordinative and persuasive. Analysis on four case based upon this typology shows different transition polices of each transition pathway in analytical aspect. It provides basic criteria for policy makers to design effective transition policies in normative aspect. Also, this paper can contribute to closing the gap between transition research and governance studies.