• 전자공학회논문지B
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• 제29B권11호
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• pp.93-101
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• 1992

HVS based transform coding techniques for still images take the lowest spatial frequency and luminance contrast sensitivity as the most crucial factors in determining the image quality perceived by human eye. Only the frequency weighting has been main issue. The proposed Weighted Discrete Cosine Transform (WDCT) has the lowest frequency of about 4 [cyc/deg] in 8$\times$8 subblock with the contrast-weighted DC coefficient. The error criteria have been rederived to adapt the contrast weighting for performance evaluation. The proposed scheme has produced higher quality images compared to the unweighted and other schemes.

• 말소리와 음성과학
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• 제3권2호
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• pp.65-70
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• 2011

Recently, audio-visual speech recognition (AVSR) has been studied to cope with noise problems in speech recognition. In this paper we propose a novel method of deciding weighting factors for audio-visual information fusion. We adopt the particle swarm optimization (PSO) to weighting factor determination. The AVSR experiments show that PSO-based normalized confidence measures (NCM) improve the rejection performance of mis-recognized words by 33%.

• 한국군사과학기술학회지
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• 제13권6호
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• pp.951-957
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• 2010

An optimal path generation method considering the safety of UGV(Unmanned Ground Vehicle) is proposed and demonstrated through examples. Among various functions of UGV, real-time obstacle avoidance is a key issue to realize realistic scenario in FCS(Future Combat Systems). A two-dimensional narrow corridor environment is considered as a test field. For each step of UGV movement, two objectives are considered: One is to minimize the distance to the target and the other to maximize the distance to the nearest point of an obstacle. A weighted objective function is used in the optimization problem. Equality and inequality constraints are taken to secure the UGV's dynamics and safety. The weighting factors are controlled by a fuzzy controller which is constructed by a fuzzy rule set and membership functions. Simulations are performed for two cases. First the weighting factors are considered as constant values to understand the characteristics of the corresponding solutions and then as variables that are adjusted by the fuzzy controller. The results are satisfactory for realistic situations considered. The proposed optimal path generation with the fuzzy control is expected to be well applicable to real environment.

• 한국재난정보학회 논문집
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• 제8권3호
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• pp.234-241
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• 2012

본 연구의 주 목적은 다층 구조를 가진 아스팔트 포장체의 피로균열에 대한 공용성 예측모델을 검정하는 것이다. 그러나, 검정 인자는 목표로 하는 예측모델, 시험법 및 시험중 하중이력에 따라 차이가 있을 수 있다. 본 연구에서 수행된 다양한 현장 조사에 의하면, 연성포장의 피로공용성은 교통하중뿐만 아니라 포장체의 완성후 경과기간에 영향을 받는 것으로 나타났다. 이에 따른 각각의 교통하중과 경과기간에 대한 가중치가 본 연구에서 제시되었다. 또한, 기 발표된 피로 예측모델을 바탕으로 실내와 현장조사를 통하여 얻어진 피로균열 데이터의 상호 상관관계를 분석하여 피로 예측모델에 대한 검정 인자가 개발되었다.

• 한국안전학회지
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• 제38권6호
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• pp.1-8
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• 2023

The health state of the oil transformer is evaluated by the age of use and the state of internal defects. Mineral Oil, used as an insulator for oil transformers, creates specific gases and compounds through chemical reactions caused by heat, moisture, and partial discharge inside the transformer. It is possible to determine the aging and defect of the transformer through these gases and compounds. So, it is an important indicator to evaluate the health of a transformer. In this study, factors for assessing the health of transformers were hierarchically categorized, and key factors for each hierarchy were selected for design weighting. These weights were determined through surveys conducted with experts in the fields of transformer design, operation, and quality. For the health of a transformer, defect-related factors are approximately three times more important than factors related to aging. Additionally, defect-related factors showed a higher weighting for gases generated at high temperatures. Furthermore, Furan was determined to have a high weight, directly associated with insulating paper aging. Based on these findings, a health index was proposed, and a comparative analysis was conducted by categorizing 40 operational transformers into normal and comparison groups to evaluate and validate it.

• 한국환경복원기술학회지
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• 제18권2호
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• pp.33-44
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• 2015

This study was performed to propose the site selection plan for the restoration of the target Narrow-mouth Frog(Kaloula borealis) habitat, and has developed the AHP model to select the optimal site for narrow-mouth frog habitat restoration on the basis of the narrow-mouth frog Habitat Suitability Index (HSI) items (factors and variables). The assessment areas were established by the narrow-mouth frog HSI factors such as space, feed, cover, water(breeding), threatening factors and others, and the sub-assessment items by each assessment area were established based on the narrow-mouth frog HSI variables. The weighting values of the assessment areas and items were calculated by the developed AHP method. The weighting values of the 5 assessment areas were arranged in order as cover(0.283), water(breeding)(0.276), feed(0.230), space(0.147), and threatening factor(0.064). The final weighting values of the 14 assessment items were arranged in order of height as low-rise grassland(0.190), soil quality(0.178), and stones and between the stones(0.105). The scoring criteria according to the assessment items and factors were marked and applied by equal intervals considering the criteria by HSI items of the narrow-mouth frog and finally the scoring criteria diagram has been proposed for the optimal site selection of the narrow-mouth frog habitat restoration.

• 한국환경복원기술학회지
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• 제18권3호
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• pp.109-118
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• 2015

This study was performed to propose the site selection plan for the restoration of the target Reeve's turtle (Maunemys reevesii) habitat and has developed the AHP model to select the optimal site for Reeve's turtle habitat restoration on the basis of the Reeve's turtle Habitat Suitability Index (HSI) items (factors and variables). The assessment areas were established by the Reeve's turtle HSI factors such as breeding space, feed, cover, water, threatening factors and others and the sub-assessment items by each assessment area were established based on the Reeve's turtle HSI variables. The weighting values of the assessment areas and items were calculated by the developed AHP method. The weighting values of the 5 assessment areas were arranged in order as breeding space(0.293), food(0.273), water(0.217), cover(0.113), and threatening factor(0.104). The final weighting values of the 17 assessment items were arranged in order of height as all kind of food(0.222), water depth(0.096), altitude of spawning ground(0.093). The scoring criteria according to the assessment items and factors were marked and applied by equal intervals considering the criteria by HSI items of the Reeve's turtle and finally the scoring criteria diagram as been proposed for the optimal site selection of the Reeve's turtle habitat restoration.

• 정보관리학회지
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• 제25권1호
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• pp.211-233
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• 2008

로치오 알고리즘에 기반한 자동분류의 성능 향상을 위하여 두 개의 실험집단(LISA, Reuters-21578)을 대상으로 여러 가중치부여 기법들을 검토하였다. 먼저, 가중치 산출에 사용되는 요소를 크게 문헌요소(document factor), 문헌집합 요소(document set factor), 범주 요소(category factor)의 세 가지로 구분하여 각 요소별 단일 가중치부석 기법의 분류 성능을 살펴보았고, 다음으로 이들 가중치 요소들 간의 조합 가중치부여 기법에 따른 성능을 알아보았다. 그 결과, 각 요소별로는 범주 요소가 가장 좋은 성능을 보였고, 그 다음이 문헌집합 요소, 그리고 문헌 요소가 가장 낮은 성능을 나타냈다. 가중치 요소 간의 조합에서는 일반적으로 사용되는 문헌 요소와 문헌집합 요소의 조합 가중치(tfidf or ltfidf)와 함께 문헌 요소를 포함하는 조합(tf*cat or ltf*cat) 보다는, 오히려 문헌 요소를 배제하고 문헌 집합 요소를 범주 요소와 결합한 조합 가중치 기법(idf*cat)이 가장 좋은 성능을 보였다. 그러나 실험집단 측면에서 단일 가중치와 조합 가중치를 서로 비교한 결과에 따르면, LISA에서 범주 요소만을 사용한 단일 가중치(cat only)가 가장 좋은 성능을 보인 반면, Reuters-21578에서는 문헌집합 요소와 범주 요소간의 조합 가중치(idf*cat)의 성능이 가장 우수한 것으로 나타났다. 따라서 가중치부여 기법에 대한 실제 적용에서는, 분류 대상이 되는 문헌집단 내 범주들의 특성을 신중하게 고려할 필요가 있다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.701-706
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• 1998

A design method of rule -based fuzzy modeling is presented for the model identification of complex and nonlinear systems. The proposed rule-based fuzzy modeling implements system structure and parameter identification in the efficient form of " IF..., THEN,," statements. using the theories of optimization and linguistic fuzzy implication rules. The improved complex method, which is a powerful auto-tuning algorithm, is used for tuning of parameters of the premise membership functions in consideration of the overall structure of fuzzy rules. The optimized objective function, including the weighting factors, is auto-tuned for better performance of fuzzy model using training data and testing data. According to the adjustment of each weighting factor of training and testing data, we can construct the optimal fuzzy model from the objective function. The least square method is utilized for the identification of optimum consequence parameters. Gas furance and a sewage treatment proce s are used to evaluate the performance of the proposed rule-based fuzzy modeling.

• 농촌계획
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• 제10권3호
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• pp.41-51
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• 2004

This study aims to develop a potential evaluation method for urban spatial expansion using remote sensing (RS) and geographic information system (GIS). A multi-criteria evaluation method with several criteria and their weighting values was introduced to evaluate the score and quantification of the potential surface around the existing cities. The six criteria with one geographic factor, slope, and five accessibility factors, time distance from center of the city, national road, interchange of expressway, a big city, and station, were defined for the potential. RS techniques were applied for classification of the actual urban expansion maps between two periods, and GIS functions were used for score of accessibility criteria with a distance decay function from geographic, road and several point maps, which was developed in this study. The new methodology was applied to a test area, Suwon, between 1986 and 1996. In order to optimize the six weighting values, this study made new findings to search the optimal combination of the weighting values from new methodology, weighted scenario method for intensity order (WSM), combined with intensity order and AHP method, including a trial and error method for sensitivity analysis to make the intensity order. The optimal combination of the weighting values by the new method generated the optimal potential surface, considering spatial trend of urban expansion in the test area.