• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1995.06a
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• pp.54-64
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• 1995

대표적인 대형 베어링인 일체형 볼 베어링과 와기어 레이스형 볼 또는 로울러 베어링의 마찰 특성을 비성형 유한요소 프로그램인 MARC를 사용하여 상호간의 마찰형상에 대한 접촉응력과 마찰력 특성을 비교 해석하였다. 특히 와이어 레이스식 슬루잉 링 베어링은 우수한 마찰특성 때문에 건설기계, 하역기계, 광산기계나 탱크와 같은 국방무기 등에서 널리 사용되고 있다. 접촉면의 변형에 따른 일체형의 볼 베어링은 마찰력과 기울기면에서 와이어 레이스식 베어링에 비하여 크고, 같은 와이어 레이스식 베어링에서는 마찰력의 경우 볼 타입이 로울러 탕입에 비하여 약간 크게 나타났다. 이들의 계산결과를 종합하면 와이어 레이스식 베어링이 일체형 베어링에 비하여 마찰특성이 우수하고, 특히 와이어 레이스 베어링중에서 로울러 타입은 마찰 토오크면에서 균일하기 때문에 베어링을 사용한 제어기능 설계에서 특히 우수한 결과를 제공할 수 있다. 유한요소 해석결과는 기존의 실험결과와 잘 일치하고 있어서 슬루잉 링 베어링의 최적설계에 유한요소 해석의 유용함을 확인하였다. 또한 상부 구조물과 하부 구조물을 연결하기 위한 체결볼트의 구멍은 하중조건에 따라서 구조적 불안정성을 야기할 수 있음도 확인하였다.

• Research in Plant Disease
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• v.7 no.2
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• pp.86-92
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• 2001

This experiment was carried out to analyze the recent epidemic of rice blast in southern provinces of Korea in 1999 and 2000. Incidences of leaf blast and panicle blast in these years were 1.5 and 2.9 times greater than those in 1998, respectively. Cultivation areas of rice cultivars, Daesan, Ilmi and Dongan bred from Milyang 95 as a recurrent parent increased over the country from 11% in 1998 to 38.4% in 2000, which were grown in more than 85% of total paddy fields in Jeonnam province. Predominant race populations of Pyricularia grisea in the farmers' fields had been changed from KJ-301 to KI-1117 in 1999 and KI-1113 and KJ-105 in 2000. Distribution ratio of the KI-1117 race in 1998 in the southern provinces was 1.7%, but increased to 30% in 1999. Although the cultivars Daesan, Ilmi and Dongan have shown wide spectrum of resistance to many races including KJ-301, they were susceptible to such races as KI-1117, KI-1113 and, KJ-105. These three races could be further classified into two sub-races, KI-1117 and KI-1117a, KI-1113 and Kl-1113a, and KJ-105 and KJ-105a based on virulence to Daesan. The newly classfied races, Kl-1113a, Kl-1117a, and KJ-l05a were also pathogenic to Ilmi and Dongan. This indicates that rice blast epidemic in southern provinces in 1999 and 2000 resulted from the breakdown of the resistance of Daesan, Ilmi and Dongan by the rapid increase of virulent races KI-1117, KI-1113, KJ-105 and their new sub-races.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3A
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• pp.227-234
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• 2009

Recently, a knee brace is usually installed in connection between cross-beam and main-girder of steel box-girder bridges. The knee brace is installed as a structural stiffener and mainly aims to relieve stress at joints and to prevent main-girder from lateral deformation. However, research on the knee brace is insufficient to obviously evaluate the necessity. The stiffened effect of knee brace is determined by using finite element analyses. Stress distribution, stress level of members and deflection of the cross-beam are evaluated by parametric FE analysis for the installation of knee brace and the depth ratio of cross-beam/steel box girder. It is seen from comparison of numerical analysis results that the knee brace installed in cross-beam of steel boxgirders bridges is not efficient as a structural stiffener with respect to stress relief and stiffened effect.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.85-93
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• 2015

This research try to find how to construct On & Off Marketplace to activate exporting of broadcasting contents by Delphi survey. This research is based on environment of broadcasting contents such as OTT and reinforcement for broadcasting contents marketplace of foreign countries. This research find that global marketplace of broadcasting contents should be constructed by convergence of online and offline, and should adopt new technology to make easy global distribution in new broadcasting environment, and also open global festival with offline marketplace of broadcasting contents. korea will be asia hub for global distribution of broadcasting contents through this task.

• The Journal of Society for e-Business Studies
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• v.9 no.2
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• pp.69-85
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• 2004

The goals of this research are to look into the logistics systems and to have a thorough grasp on the status of legal systems such as taxation and customs clearance practices and, further, to draw up an interoperable scheme seamlessly linking those two on a national scale. In this research we looked into the business process and related information of border-crossing logistics systems between B2B marketplaces. We also investigated the status of taxation systems and customs clearance practices in order to associate e-marketplaces with one another. We proposed interoperable scheme for seamless linking between B2B e-marketplace based on marketplace repository model.

• The KIPS Transactions:PartD
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• v.8D no.3
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• pp.211-220
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• 2001

A planning agent supporting customers plays a distinguished role in internet marketplaces. Although several internet marketplaces have been built with the maturity of tools based on internet and distributed technologies, there has been no actual study up to now with respect to the implementation of the planning agent. This paper describes the design and implementation of an XML-based planning agent for internet marketplaces. Since implementing internet marketplaces encounter problems similar to those in other fields such as multidatabase or workflow management systems, we first compare those features. Next we identify functions and roles of the planning agent. The planning agent is implemented using COM+, ASP, and XML, and demonstrated using real data used in an existing system.

• The Journal of Information Technology
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• v.6 no.1
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• pp.49-63
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• 2003

In recent years, the number of public e-Marketplaces have grown according to the leap-frogging advancement of network technology based on open communication architecture named Internet. However, the transaction volume through public e-Marketplaces have been an immaterial increase, and some well-known sites closed their businesses. This study proposes the public e-Marketplace as an e-Business system which has been recognized the most strategic application of business information technologies (Barrett & Konsynski, 1982; Cash & Konsynski, 1985), and suggests some future strategic and technological direction which supports a firm's transaction infrastructure under internet architecture. For this purpose, it reviews evolution of business information technologies.

• Research in Plant Disease
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• v.29 no.3
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• pp.243-250
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• 2023

To explore the distribution and the resistance reaction of rice blast pathogens that may occur in North Korea, rice blast pathogens in the North Korean border regions of Dandong and Yeon-gil in China and the North Korean border region of Cheorwon in South Korea were analyzed. In addition, comparative analysis was conducted with rice blast pathogen in Suwon and Jeonju, inland regions of South Korea. Resistance reactions above average were observed in monogenic rice lines (IRBLzt-T, IRBL9-W, IRBL20-IR24, and IRBLta-CP1) in Jeonju, Suwon, and Cheorwon from 2018 to 2020. In Dandong and Yeon-gil, the monogenic lines IRBLz5-CA, IRBL12-M, and IRBL19-A consistently showed resistance reactions for three years. Notably, IRBL19-A exhibited strong resistance. Race distribution analysis in South Korea indicated a shift from KI to KJ dominance from 2018 to 2020, while in the North Korean border regions of Dandong and Yeon-gil, the KI race was dominant in 2021 and 2022. The race distribution of rice blast pathogens in China's North Korean border regions differed significantly from that in South Korea.

• Research in Plant Disease
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• v.18 no.4
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• pp.324-330
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• 2012

This study was conducted to investigate the association of race distribution of Pyricularia oryzae with rice cultivar and location. Races present in a given location were different in cultivars, and the races from a given cultivars were different by location. For precise study of race distribution, it needs to identify isolates by considering cultivation ratio and collection area. There are great differences between the resistant degree in the upland blast nursery and on the resistant degree of the leaf blast and panical blast in the paddy field. The number of virulent races in a rice cultivar was not related with the resistant degree in blast nursery or in paddy field.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.1
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• pp.49-55
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• 2012

Asynchronous counters, where the counter value is changed not by a synchronizing clock but by outer inputs, are used in various modern digital systems such as spaceborne electronics. In this paper, we propose a scheme of fault tolerance for asynchronous counters with critical races caused by total ionizing dose (TID) in space. As a typical design flaw of asynchronous digital circuits, critical races cause an asynchronous circuit to show non-deterministic behavior, i.e., the next stable state of a state transition is not a fixed value but may be any value of a state set. Using the corrective control scheme for asynchronous sequential machines, this paper provides an existence condition and design procedure for a state feedback controller that can invalidate the effect of critical races. We implement the proposed control system in VHDL code and conduct experiments to demonstrate that the proposed control system can overcome critical races.