• 한국항행학회논문지
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• 제11권1호
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• pp.59-63
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• 2007

본 논문은 윤곽선이 불분명한 상황에서 체형의 윤곽선과 신체 내부의 그리드 패턴들을 추출하기 위한 이미지 분할 알고리즘을 서술한다. 이미지 분할 방법은 문턱 값을 이용한 이진화 기법을 사용한다. 복잡한 형상을 지닌 물체의 3차원 정보를 추출하기 위한 노이즈 제거 알고리즘은 $3{\times}3$ 하이브리드 고역통과 필터 방법을 제안한다. 본 하이브리드 고역통과 필터 알고리즘은 노이즈 제거 시간이 기존 방법에 대하여 훨씬 단축되기 때문에 3차원 체형, CAD 시스템, 공장자동화와 같은 복잡한 형상을 지닌 물체의 3차원 정보를 추출하는데 적용할 수 있다.

• 한국도로학회논문집
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• 제15권3호
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• pp.31-36
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• 2013

PURPOSES: This study is to investigate a generated traffic noise when vehicle pass over a transverse rumble strip at toll plaza of highway. METHODS: To investigate traffic noise at toll plaza of highway, Pass-by method which is the most common used for measuring traffic noise was adopted and the traffic noise at toll plaza was measured for 10 min per hour for 11hours(13:00~24:00). RESULTS: The measured traffic noise by pass-by method was changed as function of the transverse rumble strip configuration. Generally, the maximum difference among three noise measurement sections was 7 dB(A). It might be related with traffic speed. Also, the measured traffic noise was strongly generated from a passenger car which was 2 axle. It means that the most of traffic noise on the road is generated at tire/pavement interface of the passenger car. CONCLUSIONS: The traffic noise was strongly related with vehicle speed and transverse rumble strip configuration on the road. For driver safety, the transverse rumble strip is definitely necessary. However, the complaints from residents near highway was increased by traffic noise from transverse rumble strip. Therefore, To satisfy both safety and reduction of traffic noise, the development of configuration of transverse rumble strip is necessary in the further study.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2001년도 춘계 학술대회 논문집 통권 4호 Proceedings of the 2001 KSRS Spring Meeting
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• pp.128-132
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• 2001

본 연구의 수행을 위해 23개의 JERS-1 SAR 와 두 개의 ERS-2 SAR 자료를 이용하였다. 비록 ERA-2 pair로부터 생성된 인터훼로그램(interferogram)은 70일의 짧은 간격 자료임에도 불구하고 수목, 구름, 눈 등에 의한 temporal decorrelation 과 낮은 관측각에 의한 layover등에 의해 인터훼로그램의 질이 좋지 않아 분석에 이용될 수 없었다. 반면에 JERS-1 SAR(L 밴드) 자료간의 pair는 매우 긴 시간 간격에도 불구하고 비교적 높은 긴밀도를 가지고 있어, 본 연구지역과 같이 지표 변화률이 매우 느릴 것으로 예상되는 지역에서 장기간의 변화를 관측하기에는 적합하다. 우리는 altitude of ambiguities가 매우 큰 3개의 인터훼로그램과 2-pass, 3-pass DInSAR 방법을 사용하여 1992년 9월과 1998년 10월 까지 약 6년 동안의 지표변위를 관측하였다. 다양한 시간 간격(704, 1056, 1100, 1118, 1232, 2112 days) 별로의 차분 인터훼로그램(differential interferogram)의 결과와 그들간의 상호관계성를 이용하여 연구지역의 지표변위를 분석하였다. 2-pass, 3-pass, 그리고 altitude of ambiguity가 큰 인터훼로그램으로부터 관측된 결과 모두, 백두산 산체와 남서쪽에 위치하고 있는 홍두산을 중심으로 수십km에 걸쳐서 지표가 상승하고 있음을 지시한다. 계산된 지표상승률은 1년에 약 9cm 정도이다.

• Progress in Superconductivity
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• 제4권2호
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• pp.132-136
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• 2003

Extremely selective high temperature superconducting (HTS) band -pass filters were developed for the base transceiver station applications of Digital Cellular communication Service (DCS). The filters have a bandwidth of 25 MHz at a center frequency of 834 MHz. There are 12 resonators which have spiral-meander microstrip-line structures in order to reduce far-field radiations with a reasonable tunability. As a result, the size of filters is 5 mm $\times$ 17 mm $\times$ 41 mm. Device characteristics exhibited a low insertion loss of -0.4 dB with a -0.2 dB ripple and a return loss better than -10 dB in the pass-band at 65 K. The out-of-band signals were attenuated better than 60 dB about 3.5 MHz from the lower band edge, and 3.8 MHz from the higher band edge.

• Journal of Mechanical Science and Technology
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• 제16권6호
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• pp.785-798
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• 2002

A reliable analytic model that predicts the surface profile of the exit cross section of workpiece in round-oval (or oval-round) pass sequence is established. The presented model does not require any plasticity theory but needs the only geometric information on workpiece and roll groove. Formulation is based on the linear interpolation of the radius of curvature of an incoming workpiece and that of roll groove in the roll axis direction when the maximum spread of workpiece is known beforehand. The validity of the analytic model is examined by hot rod rolling experiment with the roll gap, specimen size, design parameter of oval groove and steel grade changed. Results revealed that the cross sectional shapes predicted by the model were in good agreement with those obtained experimentally. We found that the analytic model not only has simplicity and accuracy for practical usage but also saves a large amount of computational time in comparison with finite element method.

• 한국안광학회지
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• 제4권2호
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• pp.57-63
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• 1999

소의 수정체의 광투과, 흡수 Spectrum을 Spectrophotometer로 200-800nm 영역에서 측정하였다. 자외선 A-B선 모두 흡수되고 400nm 영역에서 광투과 edge가 나타나고, edge 영역보다 큰 파장에서는 완전투과형 filter가 되었다. 특히 $4^{\circ}C$-$60^{\circ}C$온도에서 광흡수 투과율의 온도조성은 없었다. 박막 설계로부터 long-pass edge filter형인 $n_0/(0.5H)L(LH)^6(0.5H)/n_s$와 $n_0{\mid}(0.5LH0.5L)^kL/1.25{\mid}4.0$ 박막 구조가 소의 수정체 광투과 Spectrum과 일치함을 알 수 있었다. 인공수정체, 안내렌즈의 설계시 박막구조 설계를 추가함으로써 자외선 차단 역할을 할 수 있다.

• Journal of Biosystems Engineering
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• 제14권1호
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• pp.41-48
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• 1989

In order to provide a basic information for the government policy in the future, rice milling costs of Small Capacity Farm-house Rice Whiteners (SCFRW) were estimated by surveying and analyzing the major factors to affect their costs. Two types of SCFRW having one stage and two stage milling process and two rice varieties, Tong-il and Akibare, were considered for their cost estimation, respectively. Also, their costs were compared with those of Private Custom-work Mill in order to determine its economical feasibility. The results were concluded as follows; 1. Major factors to affect the costs were annual milling quantity, purchase price of SCFRW and grain milling loss. 2. Total milling costs of SCFRW were a function of annual milling quantity. These costs decreased rapidly as annual milling quantity increased. 3. In comparison of milling costs between single pass type and double pass type SCFRW, the former was more economical than the latter. 4. Also, in comparison of milling costs between two varieties by using SCFRW, Akibare was less expensive than Tong-il. 5. In comparison with private Custom-work Mill, both single pass and double pass type SCFRW were less economical than private Custom-work Mill. 6. In order to have an economical feasibility, SCFRW should be designed and developed to reduce its milling loss and purchase price.

• 산경연구논집
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• 제8권2호
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• pp.5-10
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• 2017

Purpose - The purpose of this paper was to analyze the Chinese government's announcement of the RMB's appreciation on July 1, 2010, and its aim was to ascertain whether the appreciation has affected Chinese export prices by empirically measuring the degree of the exchange rate pass-tough on those prices. Research design, data, and methodology - Using 73 HS trade categories with cross-industry and time-series data, the panel estimation of a fixed-effects model has been applied to measure the degree and stability of any exchange rate pass-through effects. The estimation results show that the export prices of most trade categories were affected by the exchange rate changes. The pass-through effect was generally small, at about -0.485, and statistically significant in most export prices. Results - The empirical results indicate that China would lose its advantage and competitiveness in export if the RMB were appreciated continuously and rapidly because its export goods would no longer operate under strong monopolistic competition. Conclusions - The implications for China's exchange rate policy suggest that it would be better for the RMB to appreciate slowly and gradually rather than radically. It is clear that it would be allow the capital free flow in Chinese overall economic interest to reduce the continuous appreciation pressure on the currency and pave the way for improvements in export distribution competitiveness.

• Wind and Structures
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• 제30권1호
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• pp.85-97
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• 2020

The accurate estimation of the buffeting response of a bridge pylon is related to the quality of the bridge construction. To evaluate the influence of wind field characteristics on the buffeting response of a pylon in a trumpet-shaped mountain pass, this paper deduced a multimodal coupled buffeting frequency domain calculation method for a variable-section bridge tower under the twisted wind profile condition based on quasi-steady theory. Through the long-term measurement of the wind field of the trumpet-shaped mountain pass, the wind characteristics were studied systematically. The effects of the wind characteristics, wind yaw angles, mean wind speeds, and wind profiles on the buffeting response were discussed. The results show that the mean wind characteristics are affected by the terrain and that the wind profile is severely twisted. The optimal fit distribution of the monthly and annual maximum wind speeds is the log-logistic distribution, and the generalized extreme value I distribution may underestimate the return wind speed. The design wind characteristics will overestimate the buffeting response of the pylon. The buffeting response of the pylon is obviously affected by the wind yaw angle and mean wind speed. To accurately estimate the buffeting response of the pylon in an actual construction, it is necessary to consider the twisted effect of the wind profile.

• 한국정보과학회논문지:소프트웨어및응용
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• 제29권11호
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• pp.795-802
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• 2002

본 논문은 2-패스 점수 부여 방법에 기초한 정답 후보 색인기를 이용하여 고속, 고정밀의 질의 응답을 실현하는 한국어 질의 응답 시스템을 제안한다. 제안한 정답 후보 색인기의 색인 과정은 다음과 같다. 먼저, 대상 문서에 포함된 모든 정답 후보들을 추출한다. 그리고, 2-패스 점수 부여 방법을 이용하여 각 정답 후보와 밀접하게 연관된 주변 내용어들에게 점수를 부여한다. 마지막으로 데이터베이스에 각 정답과 점수가 부여된 내용어들을 역파일 형태로 저장한다. 사용자의 질의에 포함된 의도(질의 유형)을 파악하기 위해서는 수동으로 구축된 lexico-syntactic 패턴을 이용한다. 이러한 색인 방법과 질의 처리 방법을 이용하여, 제안된 질의 응답 시스템은 빠른 응답 시간을 보장하고 정확률을 향상시킨다.