• Proceedings of the Korean Fiber Society Conference
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• 1995.10a
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• pp.63-63
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• 1995

• 한국노년학
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• v.37 no.2
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• pp.309-328
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• 2017

The purpose of this study is to develop a perceived elderly stigma scale for intergenerational research and practice. Although negative stereotypes on elderly population have worsened physical and psychological health of older people, there has been a lack of systematic efforts to measure and monitor stigmatic perception and behavior of younger generation on elderly people. We initially constructed a 34-item perceived elderly stigma scale, by integrating the processes of literature review and exploratory item generation. After confirming the face validity of the scale, a 31-item perceived elderly stigma scale was tested with 252 adults recruited from an online research panel. The result of an exploratory factor analysis suggests a 5-factor solution with 28 items: ability, personality, appearance, authoritarian dependancy, and family-obsession. The convergent/discriminant validity was confirmed by examining its relationships with ageism, elderly discrimination, attitude toward elderly, and respect for elderly. After a series of refinement and empirical tests, the perceived elderly stigma scale would contribute to understanding the current state of elderly discrimination in our society and to develop necessary policies and promotion strategies to eliminate intergenerational conflicts.

• Fire Science and Engineering
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• v.31 no.3
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• pp.49-53
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• 2017

In the present study, the hydrodynamic force acting on the vertical wall of a portable water storage tank is examined. A Dispersion Relation Preserving (DRP) method, proposed by Jang, is applied for simulating lapping waves and their impact on the wall. A meaningful investigation has been observed, which may be applied to the strength design for the portable water storage tank.

• Explosives and Blasting
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• v.25 no.1
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• pp.45-52
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• 2007

When emulsion explosives(1kg/cartridge) are loaded into a long vertical borehole at open blasting site, they undergo an Impact corresponding to 117.6J of shock energy. After shocking. the crystallization of emulsion nay happen immediately. Furthermore, it nay cause a desensitization, arising from increase in the density of emulsion explosive by the breakage of sensitizer. In this paper, some experimental work was performed using PVC pipe equipment(50mm diameter and 12m lengths) to investigate the effects of loading impart of emulsion explosive. It is shown that detonation energy decreases up to 26% of the normal state value and this effect is less than 3% of the total performance of emulsion explosives in borehole blasting.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.8
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• pp.619-626
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• 2017

In this work, the effect of attitude angle variation on drag coefficients of hemisphere in a Mach 6 flow has been investigated. Experiments were conducted in a shock tunnel and a free-falling technique was used to minimize flow disturbance by a sting. For attitude and drag coefficient measurements of a free-falling hemisphere, a free-falling technique based on a releasing mechanism with a stair-typed module and an electromagnet was developed. A shadowgraph technique was used for flow visualization using a high-speed camera.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.11
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• pp.1130-1135
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• 2010

The main function of a landing gear is to absorb the impact energy during touchdown. Most landing gear use an oleo-pneumatic shock absorber which essentially consists of an oil damper and a gas spring. The performance of a shock absorber can be estimated by analysis but it should be verified by drop test, which is required by MIL Spec. and FAR. In the drop test, various data such as ground loads, shock absorber pressure, stroke and mass travel are analyzed to validate the shock absorbing efficiency and the mathematical model for analysis. This paper presents the introduction of drop test facility, the test procedure and data evaluation method with real drop test example.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.479-480
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• 2022

고속으로 차량이 주행하는 도로에서 정지 차량이나 낙하물은 큰 사고를 유발하기에 이에 대한 대처 방안이 요구되고 있다. 갑작스런 정지 차량의 경우 예상 불가능하며, 낙하물은 순찰대를 편성하여 주기적으로 수거하고 있으나 즉각적인 대응이 어렵다. 해당 문제 해결을 위해 본 논문에서는 딥러닝 실시간 객체인식기술을 적용하여 정지 차량 및 도로 위 낙하물을 인식하며 이에 대한 정보를 제공하는 시스템을 개발하였다. 실시간 객체인식 알고리즘인 YOLOX와 실시간 객체추적기술인 deepSORT 알고리즘을 데스크톱 PC에 적용하여 구현하였다. 개발한 시스템은 정지 차량 및 낙하물에 대한 인식 결과를 제공한다. 기존 설치된 CCTV 영상을 대상으로 시스템 적용이 가능하여 저비용으로 넓은 지역에 대한 도로 위험 상황 인식을 기대할 수 있다.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.41-48
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• 2019

Soil compaction is one of the most important activities in the area of civil works, including road construction, airport construction, port construction and backfilling construction of structures. Soil compaction, particularly in road construction, can be categorized into subgrade compaction and roadbed compaction, and is significant work that when done poorly can serve as a factor causing poor construction due to a lack of compaction. Currently, there are many different types of compaction tests, and the plate bearing test and the unit weight of soil test based on the sand cone method are commonly used to measure the degree of compaction, but many other methods are under development as it is difficult to secure economic efficiency. For the purpose of this research, a portable penetration meter called the Free-Fall Penetration Test (FFPT) was developed and manufactured. In this study, a homogeneous sample was obtained from the construction site and soil was classified through a sieve analysis test in order to perform grain size analysis and a specific gravity test for an indoor test. The principle of FFPT is that the penetration needle installed at the tip of an object put into free fall using gravity is used to measure the depth of penetration into the road surface after subgrade or roadbed compaction has been completed; the degree of compaction is obtained through the unit weight of soil test according to the sand cone method and the relationship between the degree of compaction and the depth of the penetration needle is verified. The maximum allowable grain size of soil is 2.36 mm. For $A_1$ compaction, a trend line was developed using the result of the test performed from a drop height of 10 cm, and coefficient of determination of the trend line was $R^2=0.8677$, while for $D_2$ compaction, coefficient of determination of the trend line was $R^2=0.9815$ when testing at a drop height of 20 cm. Free fall test was carried out with the drop height adjusted from 10 cm to 50 cm at increments of 10 cm. This study intends to compare and analyze the correlation between the degree of compaction obtained from the unit weight of soil test based on the sand cone method and the depth of penetration of the penetration needle obtained from the FFPT meter. As such, it is expected that a portable penetration tester will make it easy to test the degree of compaction at many construction sites, and will lead to a reduction in time, equipment, and manpower which are the disadvantages of the current degree of compaction test, ultimately contributing to accurate and simple measurements of the degree of compaction as well as greater economic feasibility.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.388-392
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• 2005

본 연구에서는 실내 수리실험을 통하여 하천에 설치된 계단형 보의 원류 흐름 특성에 따른 공기유입 효과를 산소전달 효율과 관련지어 분석함으로써, 하천의 수질 개선 효과를 검토하였다. 계단형 보 월류 흐름시 발생되는 낙하류 및 표면류에 대한 흐름의 특성을 연구하고, 공기유입의 과정을 분석하였으며, 이에 따른 산소전달 및 수질 개선효과를 분석함으로써 수질 개선에 효율적인 계단형 보의 형태를 제시하였다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.97-98
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• 2002

최근 들어 구제역과 같은 세균에 대한 경계와 관심이 늘어가고 있다. 하지만, 관심에 비하여 이에 대한 연구가 부족한 실정이고 대기질과 상호 연계한 연구는 더욱 미미한 상태이다. 따라서, 본 연구에서는 광주광역시의 시간대별 교통량과 대기질 그리고 낙하세균의 수를 함께 조사하여 상호연관성을 찾아보고자 하였다. 낙하세균은 탄저균이나 구제역처럼 전염성이나 인체에 미치는 영향은 크지 않지만 공중보건과 대기질 관리의 관점에서 이에 대한 정보 확보와 관련대책이 시급하다. (중략)