• 한국의상디자인학회지
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• 제21권4호
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• pp.17-26
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• 2019

This research aims to obtain useful data on the development of compression garment products with high-stretch knitted materials. Using nylon SCY, four specimens were knitted. Then, appearance (width, length, weight, thickness), stretch property (stretch, recovery) and clothing pressure were measured and their interrelation was analyzed. In the comparison of appearance features, yarn floating caused shrinkage in both course and wale directions of the specimens. Yarn overlapping by tucking caused a release in the course direction and shrinkage in the wale direction. Also, structural change was affected by the weight and thickness change of the knitted fabric. In the analysis of fabric stretch, yarn floating reduced the extension in course direction and increased that in wale direction of the knitted fabric. However, yarn overlapping reduced the elongation in both directions. In the analysis of recovery, yarn floating and overlapping raised fabric recovery in both directions, and tuck structure was superior to float in recovery. In the analysis of clothing pressure, 'Plain-Float' structured fabrics showed a higher clothing pressure than 'Plain' and the clothing pressure value of 'Plain-Tuck' was lower than that of 'Plain'. As for the correlation between fabric appearance, stretch property, and clothing pressure, the appearance change in course direction had a major influence on the clothing pressure. The shrinkage of appearance led to a decrease in stretch and an increase in clothing pressure.

• 한국제4기학회지
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• 제24권1호
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• pp.35-45
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• 2010

부여 능산리 왕포천 유역 충적평야에서 지형면 분류, 퇴적상분석, 연대측정 등을 행하여 충적평야의 지형발달을 밝히고 식생환경과 농경활동에 대해 고찰하였다. 왕포천 충적평야는 홀로세 해면상승과 함께 대하천인 금강의 영향을 크게 받아 형성되었으며, 자연제방, 배후습지성 범람원, 곡저평야, 구릉지로 구성되어 있다. 왕포천이 금강에 합류하는 곳에 금강의 자연제방이 폭넓게 나타나고, 중, 하류부 충적평야는 금강의 배후습지가 된다. 또한 왕포천 연안이 배후지역보다 조립질 함량이 높고 토탄층이 얇았다. 왕포천 충적층의 가장 하부 모래층은 해면하강기에 청동기인의 영향을 받아 퇴적되었고, 초기철기시대의 해면상승기에 왕포천의 수위가 높아지면서 토탄층이 형성되었다.

• Tribology and Lubricants
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• 제28권6호
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• pp.265-271
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• 2012

In the preceding Part I study, for improving the unbalance response vibration of a large PRT motor-generator rotor fundamentally by design, a series of design analyses were carried out for bearing improvement by retrofitting from original plain partial journal bearings, applied for operation at a rated speed of 1,800 rpm, to final tilting pad journal bearings. To satisfy evenly key basic lubrication performances such as the minimum lift-off speed and maximum oil-film temperature, a design solution of 5-pad tilting pad journal bearings and maximizing the direct stiffness by about two times has been achieved. In this Part II study, a detailed rotordynamic analysis of the large PRT motor-generator rotor-bearing system will be performed, applying both the original plain partial journal bearings and the retrofitted tilting pad journal bearings, to confirm the effect of rotordynamic vibration improvement after retrofitting. The results show that the rotor unbalance response vibrations with the tilting pad journal bearings are greatly reduced by as much as about one ninth of those with the plain partial journal bearings. In addition, for the tilting pad journal bearings there exist no critical speed up to the rated speed and just one instance of a concerned critical speed around the rated speed, whereas for the plain partial journal bearings there exist one instance of a critical speed up to the rated speed and two instances of concerned critical speeds around the rated speed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.733-736
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• 2008

본 연구에서는 플라이애시를 다량 사용한 콘크리트의 초기 품질 향상을 목적으로 각종 혼합재료의 종류를 변화시켜 적정량을 혼입시킨 다음 그 기초적 특성을 검토하였는데, 그 결과를 요약하면 다음과 같다. 먼저, 유동성은 전반적으로 폴리칼본산계 조강형AE감수제를 치환한 경우 가장 크게 나타났고, 공기량에서는 Plain의 경우에만 목표 공기량을 만족하는 것으로 나타났으며, 응결시간은 KOH를 치환한 경우 Plain보다 30분, 기준배합보다 약 3시간 촉진되어 가장 양호한 효과를 발휘하는 것으로 나타났다. 압축강도는 혼합재료의 종류 변화에 따라서 재령 1일 및 3일에서는 KOH를 치환한 경우, 재령 28일에서는 미분시멘트를 치환한 경우 가장 양호하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.737-740
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• 2008

본 연구에서는 플라이애시를 다량 사용한 콘크리트의 초기 품질 향상을 목적으로 각종 혼합재료의 종류를 변화시켜 적정량을 혼입시킨 다음 그 기초적 특성을 검토하였는데, 그 결과를 요약하면 다음과 같다. 먼저, 유동성은 전반적으로 폴리칼본산계 조강형AE감수제를 치환한 경우 가장 크게 나타났고, 공기량에서는 Plain의 경우에만 목표 공기량을 만족하는 것으로 나타났으며, 응결시간은 KOH를 치환한 경우 Plain보다 30분, 기준배합보다 약 3시간 촉진되어 가장 양호한 효과를 발휘하는 것으로 나타났다. 압축강도는 혼합재료의 종류 변화에 따라서 재령 1일 및 3일에서는 KOH를 치환한 경우, 재령 28일에서는 미분시멘트를 치환한 경우 가장 양호하였다.

• 한국의료질향상학회지
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• 제24권2호
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• pp.15-25
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• 2018

Purpose: To compare the Appropriateness of abdominal CT to abdominal radiography as an imaging modality in terms of the diagnostic value, medical costs and decision making times for patients presented to the emergency department with nontraumatic abdominal pain. Methods: This study used the records of 530 cases presented to the emergency department(ED) with nontraumatic abdominal pain from February to March 2012. Imaging modalities were categorized into abdominal radiography and CT (radiography first or CT first) or radiography alone or CT alone. The diagnostic value, total medical costs and effect on decision making time of the each imaging modalities were compared. Especially, in retrospective review, to evaluate the predictability of the abdominal radiography, alit was assumed that all the 530 cases performed that exam as initial imaging. Results: Among 530 cases, 255 cases underwent abdominal radiography only, 28 cases underwent abdominal CT only and the remnant 247 cases underwent abdominal CT with plain abdominal radiography. The diagnostic value was higher in the cases with abdominal CT (268/275, 97.5%) than in the cases with plain abdominal radiography (19/255, 7.5%).The number of cases predicted by abdominal radiography only as initial imaging were 39/530 (7.4%). In cases where the patients performed the abdominal CT as the first imaging modality thereby omitting the abdominal radiography, the total diagnostic imaging fee was lower than in cases with plain abdominal radiography first followed by the abdominal CT (277,140 vs. 284,226(mean, Korean Won)). Although diagnostic value of the plain abdominal radiography as first imaging modality was lower than the abdominal CT, Decision making time, average duration of hospital stay was longer and the total medical costs was higher than abdominal CT. Conclusion: As an imaging modality in the ED for patients with acute nontraumatic abdominal pain, plain abdominal radiography is an avoidable procedure when viewed in terms of the diagnostic value and total medical costs and decision making times comparing with abdominal CT.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2004년도 학술.기술논문발표회
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• pp.15-20
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• 2004

To the development on reusing method of the heat-source waste at Daegu Bisan dyeing-complex, this study is aimed to application of it's crushing material (hereafter waste sand) as concrete fine aggregate. The results are as follows; 1. Flow and unit weight of mortar using waste sand as concrete fine aggregate are decreased. 2. At the results of compressive strength test and bending strength test, mortar using waste sand superior to plain mortar within 80％ substitute ratio of waste sand. Because increasing rate of compressive strength is similar through increasing age, waste sand performs as filler's function of no-effect with cement only. 3. At the results of concrete application test, unit weight of concrete using waste sand is similar to plain concrete and compressive strength of concrete is superior to plain likewise the results of mortar test

• International Journal of Safety
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• 제8권1호
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• pp.1-5
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• 2009

The CFRP composite has unique properties that offer high strength and stiffness, even though it has light weight. Therefore it can be used in many industrial applications. When mechanical fasteners are used for joining composites, high stress concentrations appear near the edge of holes prepared for accommodating structural bolts and rivets. This presence of high stress concentrations can be a source of damage. The aim of this work is to evaluate fracture behavior and patterns of plain woven CFRP with circular hole and repairing patch element. The maximum strength and pattern for the plain woven carbon composite specimen with the repaired circular hole were examined. From the results, we show that repairing of the CFRP composite specimen with ($\pi$) 3~5 mm of circular hole diameter results in load rising effect and the repairing is more effective as bigger hole specimen.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.319-323
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• 1998

Plastic shrinkage cracking is a major concern for concrete, especially for flat structures as highway pavement, slabs for parking garages, and walls. One of the methods to reduce the adverse effect of plastic shrinkage cracking is to reinforced concrete with short randomly distributed fibers. The contribution of cellulose fiber to the plastic shrinkage crack reduction potential of cement composites and its evaluation are presented in this paper. The effects of differing amounts of fibers(0.9kg/㎥, 1.3kg/㎥, 1.5kg/㎥) were studied. The results of tests of the cellulose fiber reinforced concrete were compared with plain concrete and polypropylene fiber reinforced concrete. Results indicated that cellulose fiber reinforcement showed an ability to reduce the total area and maximum crack width significantly(as compared to plain concreted to plain concrete and polypropylene fiber concrete).

• Composites Research
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• 제13권1호
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• pp.11-24
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• 2000

평직복합재료에 있어서 두께와 적층 위상각의 변화가 기계적 거동에 미치는 영향을 수치적으로 연구하였다. 일축인장하중은 중첩법에 의한 단위구조해석에 의하여 모사되었으며 효율적인 계산을 위하여 마크로 요소 후처리기법이 사용되었다. 인접한 층간 위상각을 가지며 적층된 유한두께 평직복합재료 단위구조에 대하여 등가탄성계수를 구하였으며 단위구조를 구성하는 섬유다발 미세구조의 상세응력 분포를 계산하였다. 단일층 및 무한두께 적층형상에 대해서도 계산이 수행되었으며 그 결과가 상호 비교되었다.