• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.4
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• pp.412-424
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• 2022

Since traditional derivative-based optimization for noisy simulation shows bad performance, evolutionary algorithms are considered as substitutes. Especially in case when outputs are binary, more simulation trials are needed to get near-optimal solution since the outputs are discrete and have high and heterogeneous variance. In this paper, we propose a genetic algorithm called SARAGA which adopts dynamic resampling and fitness approximation using surrogate. SARAGA reduces unnecessary numbers of expensive simulations to estimate success probabilities estimated from binary simulation outputs. SARAGA allocates number of samples to each solution dynamically and sometimes approximates the fitness without additional expensive experiments. Experimental results show that this novel approach is effective and proper hyper parameter choice of surrogate and resampling can improve the performance of algorithm.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.469-474
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• 2007

텍스트 애니메이션 시스템에서는 자연언어 단어로 표현된 개체들을 한정된 수의 애니메이션 모델로 나타낸다. 그러나 자연언어 단어의 수에 비해 기존의 모델DB에 있는 모델의 수가 훨씬 적은 것이 일반적이기 때문에 해당 단어에 대응되는 애니메이션 모델이 존재하지 않는 경우가 있게 된다. 이러한 경우, 해당 단어가 가지는 의미를 최대한 보존할 수 있는 대체 모델을 찾을 수 있는 방법이 필요하다. 본 논문은 애니메이션에서 캐릭터 또는 사물로 표현되어야 하는 명사에 대해, 온톨로지에서 해당 명사와 상위(hypernym), 하위(hyponym), 부분(member meronymy) 관계에 있는 다른 단어를 탐색하여 적절한 모델을 찾는 방안을 제안한다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.4
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• pp.307-325
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• 1995

IN order to gain a fundamental data for forecast or control of fish behavior and evaluated the feasibility of an application of the modeling technique to a field, in this paper a numerical model for describing the behavior of fishes in a water tank was presented. The parameters of the model were estimated by using the time-series data on the three-dimensional position of fishes and by applying the least squares algorithm. The estimated parameters were standardized to examine the variation of parameters according to the number of individuals and flow speed that the mean values of parameters were to be zero and their variances were to be one. The results obtained can be summarized as follows: (1) The standardized parameter $a^*$of propulsive force decreased according to increased the number of individuals and the flow speed. (2) The standardized parameter ${k_b}^*$ of interactive force increased according to increased the number of individuals, but decreased according to the flow speed. (3) The standardized parameter ${k_c}^*$ of schooling force increased according to │increased the number of individuals and the flow speed. (4) The standardized parameter │${k_w}^{+*}$│ of repulsive force against wall or bottom increased according to increased the number of individuals, but decreased according to the flow speed. (5) The standardized parameter │${k_w}^{-*}$│ of attractive force against wall or bottom was generally constant according to increased the number of individuals, but increased according to the flow speed. (6) The standardized parameter $\upsilon$ super(*) of damping force increased according to increased the number of individuals, but decreased according to the flow speed.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.spc
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• pp.8-13
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• 2009

Mathematical models have become increasingly popular in both research and management problems involving flow and transport processes in the subsurface. Rosetta is a program to estimate unsaturated hydraulic properties from surrogate soil data such as soil texture data and bulk density. Models of this type are called pedotransfer functions (PTFs) as an alternative measurements since they translate basic soil data into hydraulic properties. These functions may be either measured directly or estimated indirectly through prediction from more easily measured data based using quasi-empirical models.

• Journal of Korean Society for Geospatial Information Science
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• v.11 no.4 s.27
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• pp.21-27
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• 2003

The rational polynomial coefficients(RPC) model is a generalized sensor model that is used as an alternative for the physical sensor model for IKONOS-2 and QuickBird. As the number of sensors increases along with greater complexity, and as the need for standard sensor model has become important, the applicability of the RPC model is also increasing. The RPC model can be substituted for all sensor models, such as the projective camera the linear pushbroom sensor and the SAR This paper is aimed at generating a RPC model from the physical sensor model of the KOMPSAT-1(Korean Multi-Purpose Satellite) and aerial photography. The KOMPSAT-1 collects $510{\sim}730nm$ panchromatic images with a ground sample distance (GSD) of 6.6m and a swath width of 17 km by pushbroom scanning. We generated the RPC from a physical sensor model of KOMPSAT-1 and aerial photography. The iterative least square solution based on Levenberg-Marquardt algorithm is used to estimate the RPC. In addition, data normalization and regularization are applied to improve the accuracy and minimize noise. And the accuracy of the test was evaluated based on the 2-D image coordinates. From this test, we were able to find that the RPC model is suitable for both KOMPSAT-1 and aerial photography.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.903-908
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• 1998

KALIMER 원자로 건물에 대하여 3차원 쉘요소 모델과 단순 빔모델을 작성하고 고유진동수 해석을 수행하였다. 두 모델의 1차 수평방향 고유진동수는 대체로 일치하였다. 단순 빔모델에 대해 원자로건물의 회전 관성모멘트를 해석에 반영한 경우 3차원 모델에는 없는 회전모드가 발생되었다. 지진응답해석은 1940 EL Centro와 인공지진에 대하여 수행하였으며, 두 결과는 면진구조물의 경우 비면진구조물과 비교하여 응답가속도가 크게 줄고, 상대변위가 증가하는 경향을 보였다.

• Journal of Korea Game Society
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• v.21 no.2
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• pp.123-138
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• 2021

This study aims to empirically prove that blockchain games can provide business model innovations through interoperability among NFT based game items. Through our research on 'PlayDapp platform', we figured out that the technological innovation of blockchain games not only has provided a positive influence to the socio-economic and industrial ecosystem perspectives, but also it differentiates companies(game developers and platform providers in this eco-system) and increases customer benefits.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.11
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• pp.874-882
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• 2013

Kerosene(Jet A-1), one of the propellants for each stage's engine of the Korea Space Launch Vehicle-II(KSLV-II), functions as coolant at the same time as it flows inside the cooling jacket of the combustion chambers and is injected through the film cooling holes. A physical surrogate mixture model to reproduce the thermophysical characteristics of Jet A-1 has been selected and the thermodynamic/transport properties of the model fuel under high pressure including supercritical conditions have been estimated using SUPERTRAPP(NIST SRD4). Comparisons with the measured properties suggest that proposed database can be used to extract properties of Jet A-1 for conjugate heat transfer analysis of liquid propellant rocket engine thrust chambers. Predicted combustion/cooling performance of regeneratively cooled thrust chambers shall be validated through comparisons with upcoming firing test results.

• Korean Journal of Legislative Studies
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• v.16 no.2
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• pp.5-37
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• 2010

본 논문은 그동안 대안적 정당모델의 하나로 제시되어 왔던 원내정당모델에 대한 오해를 불식하고 본 모델이 추구하는 이상향(ideal type)을 보다 명료화하는 것을 목적으로 한다. 이것을 위해 원내정당모델과 경쟁하는 대안적 정당모델들인 대중정당모델, 포괄정당모델, 선거전문가정당모델과 어떠한 차이를 갖는 것인지를 비교하여 논의하고자 한다. 그동안 한국 정당의 문제점을 개선하기 위한 학계의 논의는 크게 '대중정당모델'(mass party model)과 '원내정당모델'(parliamentary party model)로 수렴되어 왔다. 하지만 이 같은 두 정당모델 진영간의 논쟁이 최근까지 지속되고 있는 배경에는 바람직한 정당모델에 대한 학계의 이론적 공감대가 지체되고 있는 측면이 있다. 우선적으로 원내정당모델에 대한 개념정리를 보다 명료화할 필요가 있다. 왜냐하면 그동안 진행되어온 원내정당론자들에 대한 대중정당론자들의 비판은 대체로 '원내정당모델'이 '포괄정당'과 '선거전문가정당'과 태동배경과 강조되는 정당기능측면에서 성격이 다른 모델임에도 불구하고, 마치 같은 것으로 전제한 상태에서 진행되어 왔기 때문이다.

• Proceedings of the KSEEG Conference
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• 2000.04a
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• pp.16-17
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• 2000