• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.398-400
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• 2013

해상교통관제(VTS; Vessel Traffic Service)는 IMO RESOLUTION A.857(20) on Guidelines for Vessel Traffic Service와 해사안전법 제36조, 개항질서법 제 28조에 의거 해상운송에서의 위험을 감소하고 해상교통질서확립과 안전확보를 위하여 전세계 주요항만 및 수역에서 이용되고 있다. 최근 해상교통관제 분야에 인적요인을 도입하여 사고예방 및 감소를 도모하고 있으나 해상교통관제의 특수한 상황을 충분히 고려하지 못하고 있다. 따라서 본 연구에서는 해상교통관제와 해상교통관제사의 특수한 업무상황을 고려하여 직무를 분석하고 인간공학적 분석기법을 적용하여 사전해상상황인식을 위한 관제업무의 예측모듈을 개발하는데 목적이 있다. 본 연구를 통하여 체계적인 관제업무 분석의 프레임을 제공하고 관제사들이 효율적으로 관제업무를 수행하도록 하기 위한 실무적 업무프로세스를 제시한다.

• Water for future
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• v.28 no.5
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• pp.205-217
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• 1995

The historical data from 3, 550 event storms during 11 years in Wi-stream basin have been used to investigate the statistical parameter of the time distribution for design storms by the method of Yen-Chow, Huff, Pilgrim-Cordery and Mononobe. The dimensionless value of triangular hyetograph, $a^0$, ranges from 0.44 to 0.50 and trapezoidal hyetograph, $h^0$, value increases as the duration time is getting longer in Yen-Chow method. In the Huff, the second-quartile storms occurred most frequently and third-quartile storms occurred most infrequently. In the Pilgrim-Cordery, the shapes for shorter than 6-hour durations are advanced tendency. However, for longer than 6-hour durations show delayed tendency. In the Mononobe, every one hour rainfall occured Centered Type. The application of these methods for each duration time was tested by using the observed rainfall-runoff data of Wi-stream basin. As a result, the reappearance of hydrographs of triangular hyetograph by Yen-Chow method showed promising, and it was approved to be used for prediction of the ungaged basins.

• Journal of Navigation and Port Research
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• v.47 no.3
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• pp.120-127
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• 2023

Maritime pilots are always exposed to unpredictable risks present in the marine environment because they are boarding ships through pilot ladders or accommodation ladders at sea. Since the pilot plays an important role in securing the safety of a ship entering or departing from a port, an injury to the pilot substantially affects the overall safety of the ship. The purpose of this study is to analyze pilot injuries and predict accidents. For this purpose, pilot injury cases are analyzed and potential situations are identified through a survey. Pilot injuries are also predicted. The survey was analyzed using the IPA (Importance-Performance Analysis) methodology, and the binomial distribution and Poisson distribution were used to predict injury trends. As a result of the study, 316.8 nearmiss occurred per pilot injury, and if the current accident management system is maintained, the probability of pilot injury occurring within 3 months is 64.4%. Based on the research results, the need for a management system to prevent pilot injuries and reinforcement of maintenance and installation for pilot ladders was suggested.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.211-212
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• 2006

인공어초에 대한 정확한 개수산정은 인공어초 사후관리사업의 필요충분조건이라 할 수 있다. 그러나, 현재까지 정립된 기준 산정방법이 없으며, 개수 산정시 필요한 실체적율 또는 0.8을 관례적으로 사용하였다. 본 연구에서는 인공어초를 투하한 직후 멀티빔에코사운더를 이용한 조사를 통하여 정확한 실체적율값을 알아보았다.

• Transactions of Materials Processing
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• v.8 no.2
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• pp.143-151
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• 1999

The twisting and extrusion process of the product with trapezoidal helical fin from the round billet is developed by the upper bound analysis. The twisting of extruded product is caused by the twisted die surface connecting the die entrance section and the die exit section linearly. In the analysis, the rotational velocity in angular direction is assumed by the multiplication of radial distance and angular velocity. The angular velocity is increased linearly by axial distance from the die entrance. The increase rate of angular velocity is determined by the minimization of plastic work. The results of the analysis show that the angular velocity of the extruded product increases with the die twisting angle, the reduction of area, and decreases with the die length, the friction condition.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.73-75
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• 2014

본 논문에서는 원본 초음파 영상에서 스케일을 측정한 후, 영상의 확대 비율을 분석하여 충수염 객체의 크기에 대한 범위를 설정한다. 제안된 방법은 초음파 영상에서 ROI 영역을 추출한 후, 사다리꼴 타입의 소속 함수를 이용한 Fuzzy 이진화와 8방향 윤곽선 추적 기법을 적용하여 잡음을 제거한 후에 근막을 추출한다. 추출된 복부 근육의 근막 하단 경계선을 Cubic Spline 보간법을 이용하여 근막의 하단 영역을 추출한다. 초음파 영상의 근막을 기준으로 근막 영역을 제거한 후, SOM(Self-Organizing Map) 알고리즘을 이용하여 충수염의 후보 영역을 추출한다. 추출된 충수염의 후보 영역에 8방향 윤곽선 추적기법을 적용하여 충수염을 추출한다. 제안된 방법을 초음파 영상에 적용하여 실험한 결과, 기존의 충수염 추출 방법보다 충수염 영역이 비교적 정확히 추출되고 충수염의 크기를 측정할 수 있는 것을 실험을 통하여 확인하였다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.11 no.3
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• pp.1-8
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• 1982

When exact analytical solutions to certain type of heat conduction problems are quite cumbersome or not obtainable, it is important to introduce approximate analytical methods which are simple and useful compared with numerical methods. In this study, therefore, the Heat Balance Integral Method is applied to analysis of steady-state conduction in a straight fin of trapezoidal profile, and the two-dimensional temperature distribution in the fin and the approximate fin efficiency are obtained. Results are compared with those by the one- dimensional analysis and two-dimensional numerical analysis for a wide range of Biot numbers. It is shown that the two-dimensional temperature distribution obtained by the integral method is in good agreement with that by the finite element method at Biot numbers for which the result by the one-dimensional analysis is unreliable.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.3
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• pp.167-175
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• 2003

In this study, reflection of regular waves over a train of submerged breakwaters is experimentally investigated. Wave reflection from various-shaped submerged breakwaters is examined by using laboratory experiment and eigenfunction expansion method. Shapes of submerged breakwaters are rectangular, triangular, trapezoidal and semi-circular. Laboratory measurements are compared with predicted coefficients obtained from the eigenfunction expansion method. Although measured coefficients are slightly smaller than predicted ones, the overall agreement is very good. The present study can provide a criterion for the proper choice of a shape of submerged breakwaters in practical situation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.3
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• pp.305-313
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• 2000

The calculation of earthwork plays a major role in plan or design of many civil engineering projects, and thus it has become very important to advanced the accuracy of earthwork calculation. Current methods used for estimating the volume of pit excavation assumes that the ground profile between the grid points is linear(trapezoidal rule), or nonlinear(simpson's formulas). Generally speaking. the nonlinear profile formulas provide better accuracy than the linear profile formulas. However, all the formulas mentioned have a common drawback to ground profile, such as sharp corners or the grid points of any two straight lines. In this paper, mathematical model for a searching examination the drawbacks of the current methods is presented. Also, the presented formular, the spot height method, and chamber formulas, chen and lin method are compared with the volumes of the pits in these examples. As a result of this study, algorithm of a proposal area formula by spline method should provide a better accuracy than the spot height method, chamber formulas, chen and lin method. The mathematical model mentioned make an offer maximum accuracy in estimating the volume of a pit excavation.

• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.99-103
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• 2007

정확하고 신뢰성 높은 유량 자료는 수자원의 정량적인 계획과 관리에 필수적이다. 이를 위하여 Chiu는 기존의 결정론적인 흐름 방향 유속분포식의 한계를 극복할 수 있는 방법으로 확률통계에서 사용되는 엔트로피 개념을 이용한 3차원 유속분포 식을 제안하였고, 이를 실험실 데이터와 자연하천에 적용하여 신뢰성과 정확성을 지속적으로 증명하여 마침내 이에 대한 활용성이 매우 크게 대두되어 Chiu의 유속공식을 적극적으로 사용하고 있는 실정이다. 그러나 지금까지 이론적인 유속 분포식을 검증하기 위하여 단면 형상이 일정한 직사각형이나 사다리꼴 동의 실험수로에서부터 불규칙한 단면 형상을 갖는 자연 하천에 대한 적용을 거의 이루고 있는 실정이나, 하상경사가 변하는 경우에도 엔트로피 파라미터(M)가 이에 대응하여 평형상태에 도달하려고 하는지에 대한 연구는 전무하다. 본 연구에서는 하상경사를 임의로 변경 가능한 실험수로를 선택하여 정밀법에 의한 유속측정을 실시하였다. 같은 지점의 같은 단면에서 하상경사(${\Theta}$)가 0.000935부터 0.025794까지 28번의 경사변화를 주고 각 경사마다 유량을 측정하여 28개의 유량측정 데이터를, Chiu의 엔트로피 유속공식에 적용하여, 평균유속과 최대유속 사이의 관계가 선형관계, 즉 하상경사가 변하는 경우에도 엔트로피 파라미터(M)가 이에 대응하여 평형상태에 도달함을 증명하였다.