• 한국수소및신에너지학회논문집
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• 제31권1호
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• pp.105-111
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• 2020

The organic Rankine cycle (ORC) and the Kalina cycle system (KCS) are being considered as the most feasible and promising ways to recover the low-grade finite heat sources. This paper presents a comparative exergetical performance analysis for ORC and Kalina cycle using ammonia-water mixture as the working fluid for the recovery of low-grade heat. Effects of the system parameters such as working fluid selection, turbine inlet pressure, and mass fraction of ammonia on the exergetical performance are parametrically investigated. KCS gives lower lower exergy destruction ratio at evaporator and higher second-law efficiency than ORC. The maximum exergy efficiency of ORC is higher than KCS.

• Journal of Korean Neurosurgical Society
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• 제30권4호
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• pp.425-429
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• 2001

Objective : Patients with poor grade aneurysm usually present with increased intracranial pressure(ICP), even those without an intracranial clot. Based on this fact, the present study investigated a significance of intracranial pressure monitoring in those patients. Patients and Methods : A total of 60 patients with Hunt and Hess Grade IV(50 patients) or V(10 patients) were treated for aneurysmal subarachnoid hemorrhage(SAH) during a 3-year-period, and intraparenchymal ICP was measured in the majority, immediately after arrival to the emergency room. Early surgery including intraoperative ventriculostomy was undertaken within 3 days after SAH. An ultraearly surgery was performed without preceding angiogram or ICP monitoring in patients with large sylvian hematomas, highly suggestive of middle cerebral artery aneurysm. Outcomes were assessed by the Glasgow Outcome Scale(GOS) at 6 months. Results : In overall, favorable outcome(GOS scores 1-2) was seen in 27(54.0%) of admission Grade IV and 1(10.0%) of admission Grade V patients. Of the 38 surgical patients with preoperative ICP monitorings, 25 patients (80.6%) exhibiting ICP values of less than 40mmHg showed favorable outcome, however, no patients with ICP values above 40mmHg recovered(Fisher's exact test, p=0.0001). Conclusion : It is concluded that a preoperative ICP above 40mmHg before ventriculostomy indicate significant vital brain destruction as intractable intracranial hypertension, and Grade IV patients at admission with an ICP below 40mmHg can be of benefit from early surgical intervention while Grade V patients still remains unfavorable.

• 한국수소및신에너지학회논문집
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• 제30권6호
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• pp.621-628
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• 2019

The use of the ammonia-water zeotropic mixture as a working fluid in the power generating system has been considered as a proven technology for efficient recovery of low-grade heat sources. This paper presents a thermodynamic performance analysis for ammonia-water evaporator using low-grade heat source, based on the exergy and entransy which has been recently introduced as a physical quantity to describe the heat transfer ability of an object. In the analysis, effects of the ammonia mass fraction and source temperature of the binary mixture are investigated on the system performance such as heat transfer, effectiveness, exergy destruction, entransy dissipation, and entransy dissipation based thermal resistance. The results show that the ammonia mass concentration and the source temperature have significant effects on the thermodynamic system performance of the ammonia-water evaporator.

• 한국건축시공학회지
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• 제12권4호
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• pp.377-385
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• 2012

In this study, the Impact resistance of steel fiber and organic fiber reinforced concrete and mortar was evaluated and the improvement in toughness resulting from an increase in compressive strength and mixing fiber for impact resistance on performance was examined. The types of fiber were steel fiber, PP and PVA, and these were mixed in at 0.1, 0.5 and 1.0 vol.%, respectively. Impact resistance is evaluated with an apparatus for testing impact resistance performance by high-speed projectile crash by gas-pressure. For the experimental conditions, Specimen size was $100{\times}100{\times}20$, 30mm ($width{\times}height{\times}thickness$). Projectile diameter was 7 and 10 mm and impact speed is 350m/s. After impact test, destruction grade, penetration depth, spalling thickness and crater area were evaluated. Through this evaluation, it was found that as compressive strength is increased, penetration is suppressed. In addition, as the mixing ratio of fiber is increased, the spalling thickness and crater area are suppressed. Organic fibers have lower density than the steel fiber, and population number per unit area is bigger. As a result, the improvement of impact resistance is more significant thanks to dispersion and degraded attachment performance.

• Clinical Pain
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• 제19권2호
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• pp.120-123
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• 2020

Rapidly destructive arthrosis is a rare syndrome characterized by narrowing of the joint space and rapid joint destruction within 6~12 months. A 62-year-old woman with anaplastic lymphoma kinase rearranged non-small-cell lung cancer presented with both knee pain and varus deformity. She was treated with crizotinib 500 mg/day for more than 2 years, with partial tumor response. Initial plain radiography showed Kellgren and Lawrence (K-L) grade 1. After 10 months, varus deformity was worsened and plain radiography aggravated to K-L grade 4 despite conservative treatment including activity modification. Diffuse synovitis with massive joint effusion and destruction of anterior cruciate ligament, medial meniscus, medial collateral ligament, and lateral collateral ligament were shown in magnetic resonance imaging. The patient was diagnosed with rapidly destructive arthrosis of knee and underwent a both total knee arthroplasty.

• 한국환경과학회지
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• 제17권12호
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• pp.1391-1402
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• 2008

Designating conservation sites is needed for the preservation and management of tidal flats, and also objective criteria, by which preservation values of tidal flats can be evaluated, are required to designate conservation sites. A set of new evaluation criteria or tidal flats was suggested in this study. The criteria, based on six items including scarcity, diversity, naturalness, uniqueness, destruction possibility and preservation will, ave the advantages with which easy and economic assessments are possible by using basic data from the preceding studies. The evaluation results for the three different tidal lats (Muan, Jeungdo-1 and Jeungdo-2) in the southwestern coast of Korea reveal that all he tidal flats evaluated are classified into grade 2. The tidal flat which got the highest valuation score was Jeungdo-1 tidal flat (86.7), and the next was Muan (85.0) and Jeungdo-2 (82.5). The Jeungdo-2 tidal flat was superior in uniqueness and destruction possibility, and the Muan tidal flat was superior in diversity and naturalness.

• 한국산학기술학회논문지
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• 제12권8호
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• pp.3430-3438
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• 2011

본 연구는 감귤의 소비자 선호도 조사를 통하여 객관적인 품질기준을 제시하는데 있다. 지금까지 제주 감귤의 품질 등급은 선과기를 이용한 크기에 따른 상품 구별과, 농 감협과 일부 영농 법인에서 비파괴 선과기를 이용하여 선별되어진 감귤을 자체적인 브랜드에 준하여 등급을 제시하여 왔다. 그 등급 설정은 과학적 객관적이거나, 소비자의 니즈에 의한 것이 아니라 편의에 위한 관행적 등급으로 판단된다. 그 등급 내용을 보면 최고등급 브랜드인 경우 당도 $12^{\circ}Bx$ 이상, 산도 1% 미만을 요구하고, 다음 등급 브랜드인 경우는 당도 $11^{\circ}Bx$, 산도 1% 미만을 요구하는 등 높은 당도와 낮은 산도를 천편일률적으로 적용하여 사용되어지고 있다. 따라서 감귤의 소비자 선호도 조사를 통한 소비자 만족도에 근거하여 당도 4등급, 산도 4등급으로 총 16개 등급으로 구분하였고, 이를 바탕으로 1등급에서 5등급까지의 5개의 등급을 설정하였다.

• 자원ㆍ환경경제연구
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• 제14권1호
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• pp.25-50
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• 2005

본 연구는 조건부가치측정법(CVM)을 이용하여 생태적으로 보호가치가 있는 생태자연도 1등급지 훼손 방지를 위한 지불의사금액 방정식을 추정하고 그로부터 생태자연도 1등급지의 가치를 추정하였다. 이중 양분선택형 질문법을 이용한 조사에서 얻어진 자료의 분석 결과, 생태자연도 1등급지 10만 평 훼손 방지를 위한 가구당 연간 지불의사금액은 8,898원(95% 신뢰구간은 6,611원~1만 1,976원)으로 추정되었다. 또한 생태자연도 1등급지 10만 평 훼손 방지에 전국 가구의 연간 지불의사금액(연간의 경제적 가치)은 1,281억 원(95% 신뢰구간은 951억 원~1,724억 원)에 이르렀다. 생태자연도 10만 평의 자산 가치는 1조 7,074억 원(95% 신뢰구간 1조 2,686억 원~2조 2,980억 원)으로 추산된다. 한편 생태자연도 1등급지의 총가치 중에서 직접 사용가치는 22.0%, 간접 사용가치는 38.8%, 선택가치는 19.9%, 보전가치는 21.3%를 차지하고 있음을 알 수 있다. 연구 결과를 환경경제통합계정의 자연자산계정 작성에 직접적으로 이용하기는 한계가 있지만, 사전 환경성 평가 및 환경영향 평가에서 의사결정에 보조 자료로는 활용될 수 있을 것이다.

• 건축역사연구
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• 제27권4호
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• pp.17-30
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• 2018

The purpose of this study was to determine changes in neighborhoods due to the development of residential districts around Jangchungdan(?忠壇) altar in Seoul from the 1920s to the 1930s. In the Joseon Dynasty, this area was a protected and sacred area to honor the spirit. The reputation of the area, however, turned into the place to play and take a rest and neighborhoods around Jangchungdan altar were developed as high-grade residential districts with the impression of suburbs during the Japanese colonial period. Residential districts were formed with the destruction of the Hanyang City Wall and the privatization of nation-owned forest, which were physical and symbolic boundaries of Seoul in the Joseon Dynasty.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 1부
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• pp.7-10
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• 2011

In this study, evaluation system of impact resistance performance is proposed. Compressive strength of concrete is 40, 60 and 80MPa. It evaluate impact resistance performance to use projectile 6, 7 and 8mm size. As a result, safety performance is more higher when the compressive strength is increased in. Compared with Hughes's formula, evaluation system of impact resistance performance is appropriated.