• KSTLE International Journal
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• 제3권1호
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• pp.60-67
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• 2002

Wear on the tube-to-spring contact is investigated experimentally, The vibration of the tube causes the wear while the springs support it As for the supporting conditions, the contacting normal farce of 5 N,0 N and the gap of 0.1 mm are applied. The gap condition is for considering the influence of simultaneous impacting and sliding on wear. The wear volume and depth decreases in the order of the 5 N,0 N and the gap conditions. This is explained from the contact geometry of the spring, which is convex of smooth contour, The contact shear force is regarded smaller in the case of the gap existence compared with the other conditions. The wear mechanism is considered from SEM observation of the worn surface. The variation of the normal contact traction is analysed using the finite element analysis to estimate the slip displacement range on the contact with consulting the fretting map.

• 한국강구조학회 논문집
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• 제14권2호
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• pp.329-337
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• 2002

본 연구는 국내에서 차량의 안전주행을 유도하기 위하여 곡선교, 고가차도 등의 포장면에 설치하는 미끄럼방지포장이 강상자형 교량에 미치는 영향을 분석하기 위하여 강상자형 교량에서 현장재하시험과 전산구조해석을 실시, 상호 비교함으로서 강상자형 교량의 동적 응답을 분석하였다. 강상자형 교량의 현장재하시험에서는 미끄럼방지포장전후의 고유진동수와 동적처짐을 측정하였으며 전산구조해석에서는 현장재하시험 교량의 제원을 입력값으로 하여 미끄럼방지포장전후의 동적응답을 해석하여 현장재하시험과 상호 비교 분석하였다. 본 연구는 분석한 자료를 바탕으로 미끄럼방지포장과 같은 도로시설물이 교량의 동적응답에 미치는 영향에 대해 기초자료를 제시하는데 그 목적이 있다.

• Transactions on Control, Automation and Systems Engineering
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• 제4권4호
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• pp.341-346
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• 2002

When a construction company builds a high structure. many piles should be driven into the ground by a hammer whose weight is 7,000 kg in order to make the ground under the structure safe and strong. So. it is essential to determine whether a pile is penetrated into the ground enough to support the weight of the structure since ground characteristics at different locations are different each other. This paper proposes a visual measurement system for pile rebound and penetration movement including vibration using a high-speed line-scan camera and a specially designed mark to recognize two-dimensional motion parameters of the mark using only a line-scan camera. A mark stacking white and black right-angled triangles is used for the measurement, and movement information for vertical distance, horizontal distance and rotational angle is determined simultaneously. Especially- by adopting a line-scan CCD camera whose line rate is 20 ㎑. the measurement performance of dynamic characteristics of the pile at impact instant is improved dramatically.

• 한국양식학회지
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• 제15권2호
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• pp.79-86
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• 2002

This study is the first attempt to understand the feeding physiology of a sea-urchin larva on a red-tide dinoflagellate. Fifteen day old larvae of S. intermedius capture C. polykrikoides cells by localized reversal of ciliary beats. No failure to transporte the algal cells from theciliated band to mouth and no rejection at the mouth suggest that C. polykrikoides has no feeding deterrence to S. intermedius larvae. The trend obtained for the clearance rate of S. intermedius larvae is similar to that of other sea urchin larvae. Thus, the clearance rate decreased as the algal concentration increased. Maximum clearance rate of S. intermedius on C. polykrikoides was 17.7 $\mu l$/larva/hr. Ingestion rate rapidly increased at lower algal concentrations and saturated at higher concentrations. There was no inhibition in ingestion rate at the highest prey concentration of ca. 3000 cells/ml. Maximum ingestion rate of S. intermedius on C. polykrikoides was 131 ngC/larva/d, which is higher than that reported for the larvae of the mussel Mytilus gal-lotrovincialis, but lower than that of the ciliate Strombidinopsis sp. The grazing rate, calculated by combining the field data on algal abundances with experimental data on ingestion rate, suggests that due to its low abundance, sea urchin Iarva has no significant grazing impact on C. polykrikoides population.

• Structural Engineering and Mechanics
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• 제63권2호
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• pp.195-206
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• 2017

This paper presents the parametric numerical analysis on the ultimate bearing capacity of the purlin-sheet roofs connected by standing seam clips. The effects of several factors on failure modes and ultimate bearing capacity of the purlins are studied, including setup of anti-sag bar, purlin type, sheet thickness and connection type et al. A simplified design formula is proposed for predicting the ultimate bearing capacity of purlins. Results show that setting the anti-sag bars can improve the ultimate bearing capacity and change the failure modes of C purlins significantly. The failure modes and ultimate bearing capacity of C purlins are significantly different from those of Z purlins, in the purlin-sheet roof connected by standing seam clips. Setting the anti-sag bars near the lower flange is more favorable for increasing the ultimate bearing capacity of purlins. The ultimate bearing capacity of C purlins increases slightly with sheet thickness increasing from 0.6 mm to 0.8 mm. The ultimate bearing capacity of the purlin-sheet roofs connected by standing seam clips is always higher than those by self-drilling screws. The predictions of the proposed design formulas are relatively in good agreement with those of EN 1993-1-3: 2006, compared with GB 50018-2002.

• 한국의류산업학회지
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• 제4권4호
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• pp.347-357
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• 2002

In 1536, two Piedmontese merchants set up workshops in Lyons, and Henri IV encourged further development later in the 16th century. The development of Lyons as a centre of the silk weaving industry was helped by the perfection of drawloom weaving technique there in 1605 by Claude Dangon. In the 17th century, the French silk industry could finally compete with the dominance of the Italian silk trade. The French silk industry was promoted in the mid-17th century under Louis XIV's minister Colbert. In 1667, he published an ordinance creating La Grande Fabrique, a corporation for craftsmen within the silk industry, and Lyons became the undisputed French silk capital. Under Louis X IV, France was becoming the dominant force in Europe in matters of fashion and style. The major innovation of weaving was the Jacquard head attachment, which provided a mechanical means of raising warp threads by a series of punched cards. The are nouveau style did not have much impact on French silk design at the end of the century. Silk manufacturers began to collaborate with haute-couture designers such as the House of Worth. This collaboration with the burgeoning Paris haute-couture industry continued into the 20th century and safeguarded the future production of silk textiles in France.

• Composites Research
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• 제15권5호
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• pp.19-26
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• 2002

본 연구에서는 레이저 계측시스템을 이용하여 복합재료 구조물의 실제결함을 검출하였다. 다양한 하중을 적용하여 충격에 의한 복합재료 적층판의 층간분리, 하니컴 구조에서의 접착분리, 복합재료 적층판의 자유단 층간분리, 그리고 접착조인트 구조의 접착부위 접착부위와 같은 네 종류의 시험편을 제작하였고 ESPI와 전단 간섭계의 레이저 계측시스템으로부터 결함을 검출하였다. 열하중 방법을 통하여 시험편의 표면에 변형을 쉽게 일으켜 결함을 검출하였다. 실험결과 복합재료 구조물의 실제결함을 ESPI와 전단 간섭계로부터 쉽게 검출하였으며 더 나아가 ESPI와 전단 간섭계로부터 다양한 종류의 복합재료 구조물의 결함을 검출하는데 있어서 유용하게 이용될 것으로 사료된다.

• Asia pacific journal of information systems
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• 제12권4호
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• pp.37-53
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• 2002

The three main purposes of this paper are to (1) identify critical success factors(CSF's) for electronic commerce(EC), (2) investigate the explanatory power of these CSF's on firm performance, and (3) compare differences in evaluating CSF's and explaining impact of CSF's on performance between Korean and U.S.A. EC managers. Through a literature review and interviews with managers in EC firms, a list of 16 CSF's consisting of 111 items was compiled. In the second stage, questionnaires were administered to managers of EC companies in Seoul, Korea and Texas, U.S.A. Survey results show that CSF's have very significant explanatory power for firm performance in both Korean and U.S.A. While security, privacy, technical expertise, information about goods/services, and variety of goods/services are the most explanatory CSF's in Korea, evaluation of EC operations, technical expertise, and ease of use show most explanatory power in U.S.A. This analysis confirms the fact that customers use EC if they feel comfortable about navigating EC for information about a variety of goods/services without technical difficulty and in a secure and private way.

• The Journal of Asian Finance, Economics and Business
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• 제7권4호
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• pp.145-154
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• 2020

The paper aims to investigate the interactions between rule of law, economic growth and the shadow economy in 18 selected transition economies. This study uses annual data over the period 2002-2015 for 18 transition countries to estimate the effects of rule of law and other factors on the size of shadow economy. The transition country group is classified based on International Monetary Fund resources and is selected on the basis of the availability of data. The data examined in this research are derived from the World Bank, Worldwide Governance Indicators project and Working Paper from International Monetary Fund. This study employs GMM method. The results show that the economic growth indicators have negative and statistically significant impact on the shadow economy. Additionally, these results also reveal that in transition countries the size of shadow economy is negatively related to the quality of rule of law. However, the findings of this research also point out that there are positive relationships between inflation, public expenditure and the size of shadow economy. Hence the results from this study suggest that the size of shadow economy could be controlled by improving the effectiveness of rule of law and the growth of economy particularly in transition countries.

• 유통과학연구
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• 제17권4호
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• pp.33-39
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• 2019

Purpose - This paper examines whether product market competition in distribution and service industries is related to audit quality. This paper investigates, specifically, the relationship in distribution and service industries by using Herfindahl-Hirschman Index and audit quality measured by audit fee and audit hour. Research design, data, and methodology - Using 1,011 firm-year observations of listed companies from 2002 to 2016 in distribution and service industries, this study examines whether product market competition in distribution and service industries is related to audit quality. Results - This study finds that market competition in distribution and service industries is negatively related to audit quality and this negative relation is pronounced for the firms with high outside director groups. Further analysis suggests that the relationship between market competition and audit hours is no longer significant. Conclusions - This study extended the existing scope of the audit quality study by systematically analyzing the impact of industrial-level characteristics (i.e. market competition) in the distribution service industries on audit quality. This study, in other words, suggests the regulatory body consider the industrial-level characteristics of each industry in order to enhance audit quality.