• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.311-317
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• 2008

As outdoor environment become worse due to concentration of population in large cities, the importance of environmental control strategies such as the arrangement of green space or water space and ventilation paths, has been increasingly recognized. However, most of the studies focus on the assessment on outdoor thermal environment, few studies focus on the interrelationship between thermal environment in residential block and human thermal comfort. The aims of this study is to develop the outdoor planning method to reduce the heating/cooling load in an apartment unit or entire block by the sustainable approaches in outdoor environmental design. In this paper, on the basis of the prior studies, the effect of the outdoor thermal environment on human thermal comfort will be analysed.

• Geomechanics and Engineering
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• 제8권5호
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• pp.741-756
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• 2015

The prediction of impending collapse of deep tunnel is one of the most difficult problems. Collapse mechanism of deep tunnel in layered soils is derived using a new curved failure mechanism within the framework of upper bound theorem, and effects of seepage forces are considered. Nonlinear failure criterion is adopted in the present analysis, and the possible collapse shape of deep tunnel in the layered soils is discussed in this paper. In the layered soils, the internal energy dissipations along velocity discontinuity are calculated, and the external work rates are produced by weight, seepage forces and supporting pressure. With upper bound theorem of limit analysis, two different curve functions are proposed for the two different soil stratums. The specific shape of collapse surface is discussed, using the proposed curve functions. Effects of nonlinear coefficient, initial cohesion, pore water pressure and unit weight on potential collapse are analyzed. According to the numerical results, with the nonlinear coefficient increase, the shape of collapse block will increase. With initial cohesion of the upper soil increase, the shape of failure block will be flat, and with the lower soil improving, the size of collapsing will be large. Furthermore, the shape of collapsing will decrease with the unit weight decrease.

• Journal of Periodontal and Implant Science
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• 제43권5호
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• pp.243-247
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• 2013

Purpose: The aim of this work is to evaluate a surgical technique for mobilization of mal posed dental implant in anterior area. Methods: A 38-year-old patient consulted our unit for esthetic dissatisfaction with the implant treatment of a central incisor. An implant was observed in 11 and 21, where 11 was 3 mm above the ideal limit, with excessive vestibular angulation. The choice was made to perform a segmental osteotomy and mobilize the bone block and the implant down and forward; a bone block extracted from the mandibular ramus was installed between the implant block and the bed to stabilize the segment. Results: After 4 months, a conventional fixed prosthesis was created and the esthetic result achieved was close to what the patient wanted, with no need for further surgery. The surgical condition was stabilized and maintained for the long-time and no complications how necrosis, infection or bone defects was present. Conclusions: It was concluded that the procedure is efficient, and the biological arguments in favor of the procedure are discussed.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.366-370
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• 2003

This paper introduces a new design and fabrication technology of 28 GHz low-cost up and down converter modules for digital microwave radios, The design of the converter module is based on unit circuit blocks, which are to be characterized using a special test fixture. Based on the cascade analysis of the module the 28 GHz up and down converter modules have been designed and implemented. The measured module performance agrees with the cascade analysis. New components such as a tapped edge-coupled filter and a new Ka-band waveguide-to-microstrip transition, which are less sensitive to fabrication tolerances, have been used in the module implementation.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제22권2호
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• pp.113-127
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• 2019

본 연구의 목적은 자연수 나눗셈의 정의를 확장하여 분수 나눗셈에 적용함으로써 초등학교 수학에서 분수 나눗셈의 알고리즘을 정당화하는데 있다. 먼저 초등학교 수학에서 분수 나눗셈을 도입할 때 고려해야 할 준거들을 도출하여 제시하였다. 이를 바탕으로 분수 나눗셈의 표준 알고리즘을 유도하는 기존의 방식들이 분수 나눗셈 도입 과정에 적절한지를 고찰하였다. 또한 분수 나눗셈을 정의하였으며, 단위원 분할 모델과 정사각형 분할 모델을 통하여 구체적 조작 활동을 함으로써 등분제와 포함제 상황의 분수 나눗셈에서 표준 알고리즘을 자연스럽게 정당화하였다.

• 한국멀티미디어학회논문지
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• 제12권12호
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• pp.1769-1777
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• 2009

With the advent of the ubiquitous technology age, the progress of network technology has enabled a robust sensor communication, not just in cities, but also in poor surroundings such as deserts, polar regions, or underwater environments. In this paper, we propose a Multiple Acknowledgement (MA) technique to replace the conventional Automatic Repeat request (ARQ) technique. The MA mechanism is to send an Ack to many receivers simultaneously. The CH (master, coordinator) of the unit cluster broadcasts a Beacon frame where Ack information of the previously transmitted data is included. This technique can reduce the number of transmissions and overhead significantly. The proposed technique is a scheme improving the efficiency of an underwater sensor network where the uplink data transmission is the mainstream. The Performance of the ARQ, Block Ack, Pervasive Block Ack and the proposed method were compared with one another and analyzed. The proposed method showed significant performance improvement as compared with the ARQ, BA, and PBA in its channel efficiency.

• 한국정보통신학회논문지
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• 제24권9호
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• pp.1180-1186
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• 2020

임베디드 시스템 중 하나인 TPU (Tiny Processing Unit)를 사용하는 데에는 많은 제약들이 따른다. 외부 충격에 의해 데이터 통신 중 잡음이 발생하거나, 충분한 전력이 공급되지 않아 문턱전압을 넘지 못해 올바른 값 전달이 이루어지지 않는 경우가 있다. 이러한 문제점들을 해결하기 위해 많은 임베디드 시스템에서는 ECC (Error Correcting Code)를 사용하는데, ECC를 추가하게 되면서 메모리에서 데이터를 읽어오는 시간이 더 오래 걸리게 되는 문제점이 발생한다. 따라서 우리는 ECC 처리된 코드를 읽어오는 과정을 병렬처리하여 병목현상을 완화하고 TPU의 속도 및 데이터 안정성을 높이는 모델을 제안한다. 제안된 구조는 기존 구조에 비해 메모리를 조금 더 사용하여 안정성과 더 빠른 속도를 보여준다. 실험은 행렬의 연산을 사용하여 진행되었으며, 제안된 구조는 이전의 구조보다 7% 빠른 속도를 보여준다.

• The Korean Journal of Pain
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• 제35권3호
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• pp.303-310
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• 2022

Background: Open gastrectomy causes severe postoperative pain. Therefore, we investigated the opioid-sparing effect of the ultrasound-guided bilateral erector spinae plane block (ESPB) after open gastrectomy. Methods: Adult patients undergoing open gastrectomy were randomly assigned to either the ESPB group (ESPB + fentanyl based intravenous patient-controlled analgesia [IV-PCA]) or a control group (fentanyl based IV-PCA only). The primary outcome was total fentanyl equivalent consumption during the first 24 hour postoperatively. Secondary outcomes were pain intensities using a numeric rating scale at the post-anesthesia care unit (PACU) and at 3, 6, 12, and 24 hour postoperatively, and the amount of fentanyl equivalent consumption during the PACU stay and at 3, 6, and 12 hour postoperatively, and the time to the first request for rescue analgesia. Results: Fifty-eight patients were included in the analysis. There was no significant difference in total fentanyl equivalent consumption during the first 24 hour postoperatively between the two groups (P = 0.471). Pain intensities were not significantly different between the groups except during the PACU stay and 3 hour postoperatively (P < 0.001, for both). Time to the first rescue analgesia in the ward was longer in the ESPB group than the control group (P = 0.045). Conclusions: Ultrasound-guided ESPB did not decrease total fentanyl equivalent consumption during the first 24 hour after open gastrectomy. It only reduced postoperative pain intensity until 3 hour postoperatively compared with the control group. Ultrasound-guided single-shot ESPB cannot provide an efficient opioid-sparing effect after open gastrectomy.

• 교육녹색환경연구
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• 제8권2호
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• pp.40-50
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• 2009

The toilet in school building is one of most crucial elements for the recent changing face in school design, but the number of toilets and urinals in most school may not be sufficient to meet current needs, especially in the girl's toilet rooms. This study aims to suggest a guideline in designing the toilet in school buildings and propose the optimum area and development of models. The survey for this study is conducted through questionnaires collected and research from 9 schools in Seoul. The results of this study, it is suggested that the number of toilet facilities in school buildings be required by ratio of 0.5 toilets per a class and 1.1 urinal per a class for boy. In case of girls, it is suggested that ratio of 1.6 toilets per a class. Based on the result, it also propose various unit plans for each class block with space such as rest zone, green zone, powder zone etc.

• 방송공학회논문지
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• 제19권5호
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• pp.627-630
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• 2014

최신 비디오 부호화 표준인 HEVC(High Efficiency Video Coding)에서는 재귀적으로 동일한 4개의 블록으로 분할될 수 있는 쿼드 트리 기반의 부호화단위(CU: Coding Unit) 구조를 적용하여 높은 부호화 효율을 얻는다. 각 깊이(depth) 레벨에서 각 CU는 가변 크기의 예측단위(PU: Prediction Unit)로 분할된다. 하지만 각 부호화트리단위(CTU: Coding Tree Unit) 마다 최적의 CU 분할구조와 각 CU 마다 최적의 PU 모드를 결정하기 위한 상당한 계산 복잡도 증가를 야기한다. 본 논문에서는 이러한 계산 복잡도를 줄이기 위하여 PU 탐색을 조기 종료하는 고속 PU 결정 기법을 제시한다. 제한 기법은 상위 깊이 CU의 최적 모드와 부호화 율-왜곡 비용을 이용해서 현재 깊이 CU에서의 특정 모드의 율-왜곡 비용 계산을 생략함으로써 PU 탐색을 조기 종료한다. 실험결과 제안기법은 HM 12.0 대비 0.2%의 비트 증가에 18.1%의 계산시간 감소 효과를 얻을 수 있음을 확인하였다.