• 대한기계학회논문집B
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• 제25권3호
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• pp.356-365
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• 2001

Heat (mass) transfer characteristics have been investigated on the endwall of a large-scale linear turbine cascade. Its profile is based on the mid-span of the first-stage rotor blade in a industrial gas turbine. By using the naphthalene sublimation technique, local heat (mass) transfer coefficients are measured for two different free-stream turbulence intensities of 1.3% and 4.7%. The results show that local heat (mass) transfer Stanton number is widely varied on the endwall, and its distribution depends strongly on the three-dimensional vortical flows such as horseshoe vortices, passage vortex, and corner vortices. From this experiment, severe heat loads are found on the endwall near the blade suction side as well as near the leading and trailing edges of the blade. In addition, the effect of the free-stream turbulence on the heat (mass) transfer is also discussed in detail.

• 한국동물학회지
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• 제32권1호
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• pp.9-13
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• 1989

인천의 인근지역인 척전 조간대 사니질 간척지의 해양저서생물의 생태학적 연구를 위한 조사 과정에서 이 지역 조간대 하부의 사니질 구역에서 한국 미기록종인 대형 빗갯지렁이를 발견하였기에 그 형태적 기재와 추적학적 의의를 고찰하였다. 긴빗갯지렁이는 지금까지 보고된 빗갯지렁이류에 비하여 대형인 것이 특징이며 그 밖에도 (1) 머리부분의 등쪽 뒷편에 약 20-25개의 톱니모양의 막으로 연결되어 있으며, (2) 꼬리판 위에 좌우로 19-24개의 갈고리 모양의 가시를 갖는다.

• 비교문화연구
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• 제27권
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• pp.123-143
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• 2012

China's Yueyanglou(岳陽樓) cultural landscape and cultural landscape of Korea, respectively Yueyanglou(岳陽樓) investigated and the following results were extracted. First, multi-cultural personalities to ever Yueyanglou(岳陽樓) China's outstanding natural beauty around the emotion of his drawing on the literature and a new cultural landscape was formed. Their main feeling of the beauty of nature through his ash under adverse conditions up again in politics, which expresses the desire to advance. To this end, his outlook on life and also an attitude overhaul yeotboinda. This information formed the cultural landscape of Korea Yueyanglou(岳陽樓) not deviate from that has been investigated. Second, Korea is entirely China's 'sun' Lou Yueyanglou(岳陽樓) was a significant effect of cultural landscape. The beautiful landscapes of the Joseon Dynasty literati in the Joseon reported only in words and pictures they admired China's leading natural and cultural landscape and paste the name of the famous' sun Lou watch it was transformed into a cultural landscape. For this reason, the current remaining two 'sun' Lou, but probably the Joseon Dynasty, called the 'sun tower base and is estimated to be more common than now. In addition, in Hadong Yueyanglou(岳陽樓) near the sun 'Lou, China has also attached near the nomination could be an important clue.

• 한국산업융합학회 논문집
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• 제24권1호
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• pp.61-67
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• 2021

With the recent development of bathemetry technology, the hydrographic surveying method has been changed from single beam depth device use to multi beam acoustic sounding technology. Also, various studies have been reported to obtain high accuracy and precision in the process of river bed topographic data. Especially south korea is geographically on three sides of the sea and the river topography is very developed. To build information about the underwater, and riverbed status, the public investigations has been continuously progressed. In this study, We investigasted the riverbed topography near Baeckma river leisure park. for this purpose, In this study, as the first preliminary survey, location of navigational dangerous objects and reefs and the dangerous areas are identified. Also, ground control points is selected for the optimal GPS surveying. Secondary, through test surveying the Gain, TVG, and pulse length are determined. In addition, the investigation of dangerous objects for navigation is also conducted. As the last step, the error analysis are conducted for the acquired data, and this process involves the removal and adjustments of errors. This section includes the analysis of tide level and navigational contributions, and finally generates a submarine topographic map.

• Geomechanics and Engineering
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• 제17권5호
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• pp.413-420
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• 2019

The changes in earth pressure and ground settlement due to underground excavation near an existing retaining wall were studied experimentally according to the separation distance between the underground excavation and the retaining wall. In addition, this study attempted to experimentally prove that the arching phenomenon occurred during the construction of the underground space. A model tank having 120 cm in length, 160 cm in height, and 40 cm in width was manufactured to simulate underground excavation through the use of five separated base wall bodies. The variation of earth pressure on the retaining wall was measured according to the underground excavation phase through the use of 10 separated right wall bodies. The results showed that the earth pressure on the retaining wall was changed by the lowering of the first base bottom wall; however, the earth pressure was not changed significantly by the lowering of the third base bottom wall, since the third base wall had sufficient separation distance from the retaining wall. Lowering of the first base wall induced a decrease in the earth pressure in the lower part of the retaining wall; in contrast, lowering of the first base wall induced an increase in the earth pressure in the middle part of the retaining wall, proving the arching effect experimentally. It is necessary to consider the changes in earth pressure on the retaining wall in designing earth retaining structures for sections where the arching effect occurs.

• Structural Engineering and Mechanics
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• 제87권6호
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• pp.529-540
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• 2023

A novel laminated-hybrid-composite-beam (LHCB) of glass-epoxy infused with flyash and graphene is constructed for this study. The conventional mixture-rule and constitutive-relationship are modified to incorporate filler and lamina orientation. Eringen's non-local-theory is used to include the filler effect. Hamilton's principle based on fifth-order-layer-wise-shear-deformation-theory is applied to formulate the equation of motion. The analogous shear-spring-models for LHCB with multiple-cracks are employed in finite-element-analysis (FEA). Modal-experimentations are conducted (B&K-analyser) and the findings are compared with theoretical and FEA results. In terms of dimensionless relative-natural-frequencies (RNF), the dynamic-response in cantilevered support is investigated for various relative-crack-severities (RCSs) and relative-crack-positions (RCPs). The increase of RCS increases local-flexibility in LHCB thus reductions in RNFs are observed. RCP is found to play an important role, cracks present near the end-support cause an abrupt drop in RNFs. Further, multiple cracks are observed to enhance the nonlinearity of LHCB strength. Introduction of the first to third crack in an intact LHCB results drop of RNFs by 8%, 10%, and 11.5% correspondingly. Also, it is demonstrated that the RNF varies because of the lamina-orientation, and filler addition. For 0° lamina-orientation the RNF is maximum. Similarly, it is studied that the addition of graphene reduces weight and increases the stiffness of LHCB in contrast to the addition of flyash. Additionally, the response of LHCB to moving mass is accessed by appropriately modifying the numerical programs, and it is noted that the successive introduction of the first to ninth crack results in an approximately 40% to 120% increase in the dynamic-amplitude-ratio.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.170.1-170.1
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• 2016

$Bi_2Te_3$ has long been studied for its excellent thermoelectric characteristics. Recently, this material has been known as a topological insulator (TI). The surface states within the bulk band gap of a TI, which are protected by the time reversal symmetry, contribute to the conduction at the surface, while the bulk is in insulating state. In contrast to the bulk defects tuning the chemical potential to the Dirac energy, the native defects near the surface are expected not to change the shape of the Fermi surface and the related spin structure. Using scanning tunneling microscopy (STM), we have systematically characterized surface or near surface defects in p- and n- doped $Bi_2Te_3$, and identified their structure by first principles calculations. In addition, bias-polarity dependences of STM images revealed the electron donor/acceptor nature of each defect. A detailed theoretical study of the surface states near the Dirac energy reveals the robustness of the Dirac point, which verifies the effectiveness of the disturbance on the backscattering from various kinds of defects.

• Journal of Korean Dental Science
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• 제3권2호
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• pp.4-11
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• 2010

Purpose: This study aimed at examining the thickness of lateral cortical bone in the mandibular posterior body and the location of the inferior alveolar nerve canal as well as investigating the clinically viable bone grafting site(s) and proper thickness of the bone grafts. Subjects and Methods: The study enrolled a total of 49 patients who visited the Department of Oral and Maxillofacial Surgery at Kyung Hee University Dental Hospital to have their lower third molar extracted and received cone beam computed tomography (CBCT) examinations. Their CBCT data were used for the study. The thickness of lateral cortical bone and the location of inferior alveolar nerve canal were each measured from the buccal midpoint of the patients' lower first molar to the mandibular ramus area in the occlusal plane of the molar area. Results: Except in the external oblique ridge and alveolar ridge, all measured areas exhibited the greatest cortical bone thickness near the lower second molar area and the smallest cortical bone thickness in the retromolar area. The inferior alveolar nerve canal was found to be located in the innermost site near the lower second molar area compared to other areas. In addition, the greatest thickness of the trabecular bone was found between the inferior alveolar nerve canal and the lateral cortical bone. Conclusions: In actual clinical settings involving bone harvesting in the posterior mandibular body, clinicians are advised to avoid locating the osteotomy line in the retromolar area to help protect the inferior alveolar nerve canal from damage. Harvesting the bone near the lower second molar area is judged to be the proper way of securing cortical bone with the greatest thickness.

• 감성과학
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• 제21권2호
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• pp.73-88
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• 2018

본 연구는 손과 가까운 시각 정보의 처리적 특성이 과제전환에 미치는 영향을 살펴보기 위해 수행되었다. 최근 연구들은 손과 가깝게 제시된 정보에 대한 인지통제가 향상됨을 보고하고 있다. 이러한 인지통제 향상효과를 손 근접성과 주의의 관계를 통해 규명하고자 두 번의 실험을 실시하였다. 그 결과 과제전환 수행에서 단서와 목표자극의 감각양상에 따라 손 근접성의 효과가 달라짐을 관찰할 수 있었다. 첫 번째 실험에서 손에 근접한 자극에 대한 전환비용의 감소가 관찰되었다. 선행 연구들에서 전환비용의 감소원인으로 지목되었던 특징결합 문제를 제외시켰을 경우에도 동일한 결과가 관찰되었다. 즉, 손 근접성이 전환비용을 감소시켰음을 검증할 수 있었다. 두 번째 실험에서는 손 근접성과 감각양상의 상호작용이 전환비용에 미치는 영향을 살펴보기 위해 수행되었다. 과제전환에서 목표자극은 시각으로 단서는 시각 또는 청각으로 제시하였고, 단서의 준비성 효과를 관찰하기 위해 단서-목표자극 간격을 조변하였다. 연구 결과 손에 근접한 시각 단서는 과제 준비 시간을 단축시켜 전환비용을 감소시켰으나, 청각 단서의 경우 손에 근접할 때 오히려 과제 준비 시간이 더 오래 걸렸다. 시각 단서의 결과는 손에 근접한 시각 정보에 대한 신속한 주의정향으로 인한 이득으로 설명될 수 있다. 반면에 청각 단서에서 나타난 손실은 청각 단서와 시각 자극 간의 감각 간 전환이 손 근접성의 주의 범위 고정 효과로 인해 방해된 결과로 해석될 수 있다. 마지막으로 손 근접성의 주의효과로 인해 달라지는 전환비용에 대해 논의하였다.

• 핵의학기술
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• 제14권2호
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• pp.138-144
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• 2010

급변하는 의료환경 속에서도 변함없이 의료기관들은 환자 안전관리 부분의 중요성을 인식하여 관리하고 있다. 하지만 현재 환자안전관리는 사후관리와 처벌이 강조된 프로세스들로 조직원들의 참여성이 결여된 문제를 보이고 있다. 본원 핵의학과 에서는 참여형 니어미스 사고예방 활동을 시행하여 환자안전사고에 사전관리를 시작하고 사고보고에 따른 불이익이 없는 시스템을 구축하여 니어미스 감소 와 환자안전사고 제로화를 목적으로 본 연구을 시작하였다. 또한 핵의학과만의 차별화된 환자안전관리System구축도 그 목적으로 하고 있다. 1. 팀원들의 과거 니어미스 및 현재 발생되고 있는 니어미스와 사고 사례수집(1차 자료수집). 2. 설문을 통해 중요도, 긴급도를 파악하고 니어미스 및 사고사례를 정량화(2차 자료수집). 3. 자료 분석을 통한 중요 접점 파악과 사고 사례 정량화. 4. 중요 접점 부분에 대한 매뉴얼 제작과 표준화, 오류방지를 위한 참여형 개선활동 시행. 5. 니어미스 보고체계 구축을 위한 웹 기반 커뮤니티 활동. 6. 설문과 FGI를 통해 활동 전후 평가 시행. 1) 비계량적이었던 핵의학과 내 안전사고 및 니어미스를 계량화(월 50여 회의 니어미스와 년 1건의 안전사고발생) 2) 계량화된 데이터를 통해 개선방안을 수립(0여건의 참여형 개선활동, 프로세스 개선, 표준화를 위한 약속 매뉴얼 제작) 3) 안전문화 시스템을 형성하고 팀원들의 높은 관여도를 형성.(보고체계구축, 체크리스트 제작, 안전문화 슬로건 제작, 평가 인덱스 구축) 4) 니어미스 및 사고 사례를 공유하고 반면교사로 삼기 위한 커뮤니티 개설. 5) 활동 전후 니어미스 발생률은 50% 감소 하였고 안전사고 제로. 핵의학과의 최고의 서비스는 환자안전이 보장된 양질의 검사와 치료를 제공하는 것이다. 참여형 개선활동으로 니어미스사고를 예방하고 안전문화를 형성하여 시스템을 구축함으로써 니어미스 발생 사례는 50% 줄었으며 안전사고는 발생하지 않았다. 이는 환자안전사고의 사전관리란 측면에서도 시사하는 바가 있다. 또한 불이익이 없는 사고보고체계도 마련하여 솔직하게 보고하고 인정하는 문화도 만든 계기가 되었다. 기본에 충실한 뛰어난 시스템은 환자에게 제공되는 최고의 서비스이며 형성된 안전문화 시스템은 결국 고객만족으로 이어질 것이다. 따라서 본원 핵의학과 에서는 마련된 시스템을 정착하고 안정시켜 차별화된 환자안전문화를 형성해 나가고자 한다.