• 한국항해항만학회지
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• 제40권5호
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• pp.265-270
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• 2016

Extreme tropospheric anomalies such as typhoons or regional torrential rain can degrade positioning accuracy of the GPS signal. It becomes one of the main error terms affecting high-precision positioning solutions in network RTK. This paper proposed a detection algorithm to be used during atmospheric anomalies in order to detect the tropospheric irregularities that can degrade the quality of correction data due to network errors caused by inhomogeneous atmospheric conditions between multi-reference stations. It uses an atmospheric grid that consists of four meteorological stations and estimates the troposphere zenith total delay difference at a low performance point in an atmospheric grid. AWS (automatic weather station) meteorological data can be applied to the proposed tropospheric anomaly detection algorithm when there are different atmospheric conditions between the stations. The concept of probability density distribution of the delta troposphere slant delay was proposed for the threshold determination.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
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• pp.480-483
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• 2000

공학의 많은 응용분야에서 큰 회소 행렬(Large Sparse Matrices)에 대한 가장 작거나 또는 가장 큰 고유치(Eigenvalues)들을 요구하게 되는데, 이때 많이 이용되는 것은 Krylov Subspace로의 Projection방법이다. 대칭 행렬에 대해서는 Lanczos방법을, 비대칭 행렬에 대해서는 Biorhtogonal Lanczos방법을 이용할 수 있다. 이러한 기존의 알고리즘들은 새롭게 제안되는 병렬처리 시스템에서 효과적이지 못하다. 많은 프로세서를 가지는 병렬처리 컴퓨터 중에서도 분산 기억장치 시스템(Distributed Memory System)에서는 프로세서들 사이의 Data Communication에 필요한 시간을 줄이도록 해야한다. 본 논문에서는 기존의 Lanczos 알고리즘을 수정함으로써, 알고리즘의 동기점(Synchronization Point)을 줄이고 병렬화를 위한 입상(Granularity)을 증가시켜서 MPP인 Cray T3E에서 Data Communication에 필요한 시간을 줄인다. 많은 프로세서를 사용하는 경우 수정된 알고리즘이 기존의 알고리즘에 비해 더 나은 speedup을 보여준다.

• 한국산업정보학회논문지
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• 제4권4호
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• pp.88-93
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• 1999

선형독립인 소수의 벡터들을 직교화 시키는 방법인 Cram-Schmidt 알고리즘, 몇 개의 극단적인 고유치를 구하는 방법인 란초스 알고리즘방법 등이, 한번의 반복동안 한번의 동기점만 가지도록 재구성된다. 즉 메시지 패싱 분산시스템에서 모든 프로세서들 사이에 한번의 통신만 요구되도록 알고리즘을 변화시킨다. 이러한 알고리즘들은 재구성되었다고 하며, 전통적인 방법에 비하여 더 나은 병렬성질을 가지게 된다.

• 한국경영과학회지
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• 제25권4호
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• pp.111-122
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• 2000

This paper considers remanufacturing planning problems under deterministic environments. As increasing the environmental pressures in manufacturing, various methods for reducing wasted or postponing the time to be waste are considered. This paper considers remanufacturing planning problems on a single facility, where the wastes(or used products) are remanufactured to satisfy the given demand on the remanufactured products. The objective is to find the optimal remanufacturing and purchasing planning of the wastes which minimize total cost subject to satisfaction all the given demand on the remanufactured products. Two problems that the amount of wastes is a given constant or a decision variable are considered, respectively. For the problems, the extreme point solutions are characterized, and dynamic programming algorithms are developed with numerical examples.

• 한국경영과학회지
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• 제19권2호
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• pp.119-128
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• 1994

There are three important regions im Multiple Objective Linear Programming (MOLP). One is the region of efficient solutions, another is the region of weight to be used for finding efficient solutions, the third is the region of efficient (nondominated) objective values. In this paper, first, we find the condition of extreme point in the region of efficient objective values. Second, we find that the sum of the dimension of the weight region and the dimension of efficient objective values region is constant. Using the above, it is shown that we find the shape and dimension of weight region corresponding to the given region or efficient objective values and vice versa.

• Management Science and Financial Engineering
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• 제7권1호
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• pp.41-56
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• 2001

This linear fractional - quadratic bilevel programming problem, in which the leader's objective function is a linear fractional function and the follower's objective function is a quadratic function, is studied in this paper. The leader's and the follower's variables are related by linear constraints. The derivations of the optimality conditions are based on Kuhn-Tucker conditions and the duality theory. It is also shown that the original linear fractional - quadratic bilevel programming problem can be solved by solving a standard linear fractional program and the optimal solution of the original problem can be achieved at one of the extreme point of a convex polyhedral formed by the new feasible region. The algorithm is illustrated with the help of an example.

• 한국환경과학회지
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• 제29권10호
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• pp.981-988
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• 2020

This study presents meteorological data integrity to improve environmental quality assessment in Yongdam catchment. The study examines both extreme ranges of meteorological data measurements and data reliability which include maximum and minimum temperature, relative humidity, dew point temperature, radiation, heat flux. There were some outliers and missing data from the measurements. In addition, the latent heat flux and sensible heat flux data were not reasonable and evapotranspiration data did not match at some points. The accuracy and consistency of data stored in a database for the study were secured from the data integrity. Users need to take caution when using meteorological data from the Yongdam catchment in the preparation of water resources planning, environmental impact assessment, and natural hazards analysis.

• 한방안이비인후피부과학회지
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• 제20권3호
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• pp.243-250
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• 2007

Trigeminal neuralgia is nerve systematic disease appearing in the distribution scope of trigeminal nerve. It's characterized by extreme pain accompanying with a repeated and simultaneous fit from several seconds to 1-2 minutes. The oriental medical name of trigeminal neuralgia is generally Dootong, Doopoong, Myuntong, Pyundootong, Pyundoopoong, and Myuntong is the nearest in Occidental medicine. So I study for general prescription of Trigeminal neuralgia and point out Galgunhaegui-tang(葛根解肌湯). Trigeminal neuralgia patients were given Galgunhaegui-tang. After taking Galgunhaegui-tang, the patients's Trigeminal neuralgia was improved.

• 산업기술연구
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• 제35권
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• pp.47-53
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• 2015

Recent extreme weather events and natural disasters are causing rapid aging of the ancient structures with cultural value. It has threatened the safety and management. The construction design documents are not kept for such long time. Even if they are, they seem to be mismatched with the design structures due to corrosive effects. For these reasons, Korea has been facing difficulties in maintenance, reengineering and safety evaluation. In this study, three dimensional point cloud surface of bobsleigh is obtained using 3D LiDAR scanner. The obtained structure is compared with the original design and found to be highly accurate. The study shows the application of reverse engineering technique and its potential use for other civil structures.

• 대한산업공학회지
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• 제31권3호
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• pp.240-247
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• 2005

Today's hightech society requires thousands of different products which ultimately result in billions of tons of materials discarded, most of which end up in landfills. Therefore industrial circles could not help thinking about environmental problems by regulations of government or pressures of consumer. Generally, the related research subjects are classified into both of environmentally conscious manufacturing and product recovery, where product recovery aims to minimize the amount of waste sent to landfills by recovering materials and parts from old or outdated products by means of recycling and remanufacturing (including reuse of parts and products). In this research, we constructed a model for remanufacturing various goods using a single facility and developed a dynamic programing(DP) algorithm based upon the optimal solution characterization. We showed the efficiency of the developed DP algorithm with a numerical example.