• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.262-271
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• 2003

Specification of reinforcement method was suggested according to the ground condition and tunnelling environment such as adjacent building and surface settlement. Tunnel database consists of 8 different groups of data according to the tunnel construction situations and major problems of ground. A tunnel countermeasure expert system based on client/server system was developed with on-line. The expert system provides proper solution to the each construction sites backing up the information of the tunnelling and ground information through Internet. The effective factors of tunnel construction were shown by the analyzing relationship and partial relationship between face stability and RMR factors. This study will be very helpful to make the most of in-situ data and suggest proper applicability of tunnel reinforcement system escaping from the dependence of some experienced experts for the absent of guide.

• 한국통신학회논문지
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• 제26권7A호
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• pp.1144-1151
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• 2001

본 연구에서는 AOA(Angle of Arrival)와 TOA(Time of Arrival) 그리고 TDOA(Time Difference of Arrival)의 추정값을 이용한 위치 추정 기법들이 설명되고 분석된다. 이들 기법들을 다중경로 페이딩 (mutipath fading)과 shadowing을 갖는 마이크로셀 환경에 적용한다면, 빠르고 예측할 수 없는 신호 레벨의 변화로 인하여 이동체의 위치를 정확히 추정하는 것은 어렵다. 따라서 본 연구에서는 수신 신호 세기(RSS: Received Signal Strength) 이외에 이동체와 기지국간의 거리, 이동체의 이동방향, 이동체의 이전위치와 같은 부정확한 다수의 파라미터를 동시에 고려하는 퍼지 다기준 (multi-criteria) 의사 결정 방법을 이용하여 이동체의 위치를 결정하는 방법을 제안한다. 시뮬레이션을 통하여, 이동체의 방향과 속도의 영향을 분석한다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.1137-1140
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• 1993

A dynamic-structure system is one that has the flexibility to change the system configuration automatically so as to operate in an optimal manner. A conceptural model for a dynamic-structure system is presented in this paper. In this model, the interchangeable components of the overall system are grouped together. Their activity levels are evaluated by an intelligent preprocessor that is associated with the group. A knowledge-based task distribution system evaluates the activity levels and makes decisions as to how the components operating below capacity should be shared with workcells that have similar components that are overloaded. Associated decision making can be effected through fuzzy logic and particularly the compositional rule of inference. A simulation example is given to illustrate the application of dynamic structuring.

• Journal of Oral Medicine and Pain
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• 제47권2호
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• pp.107-108
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• 2022

Artificial intelligence (AI) refers to the use of machines to mimic intelligent human behavior. It involves interactions with humans in clinical settings, and augmented intelligence is considered as a cognitive extension of AI. The importance of AI in healthcare and medicine has been emphasized in recent studies. Machine learning models, such as genetic algorithms, artificial neural networks (ANNs), and fuzzy logic, can learn and examine data to execute various functions. Among them, ANN is the most popular model for diagnosis based on image data. AI is rapidly becoming an adjunct to healthcare professionals and is expected to be human-independent in the near future. The introduction of AI to the diagnosis and treatment of oral diseases worldwide remains in the preliminary stage. AI-based or assisted diagnosis and decision-making will increase the accuracy of the diagnosis and render treatment more precise and personalized. Therefore, dental professionals must actively initiate and lead the development of AI, even if they are unfamiliar with it.

• Advances in Energy Research
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• 제5권2호
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• pp.107-128
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• 2017

Energy is a major component of almost all economic, production, and service activities, and rapid population growth, urbanization and industrialization have led to ever growing demand for energy. Limited energy resources and increasingly evident environmental effects of fossil fuel consumption has led to a growing awareness about the importance of further use of renewable energy sources in the countries energy portfolio. Renewable hydrogen production is a convenient method for storage of unstable renewable energy sources such as wind and solar energy for use in other place or time. In this study, suitability of 25 cities located in Iran's western region for renewable hydrogen production are evaluated by multi-criteria decision making techniques including TOPSIS, VIKOR, ELECTRE, SAW, Fuzzy TOPSIS, and also hybrid ranking techniques. The choice of suitable location for the centralized renewable hydrogen production is associated with various technical, economic, social, geographic, and political criteria. This paper describes the criteria affecting the hydrogen production potential in the study region. Determined criteria are weighted with Shannon entropy method, and Angstrom model and wind power model are used to estimate respectively the solar and wind energy production potential in each city and each month. Assuming the use of proton exchange membrane electrolyzer for hydrogen production, the renewable hydrogen production potential of each city is then estimated based on the obtained wind and solar energy generation potentials. The rankings obtained with MCDMs show that Kermanshah is the best option for renewable hydrogen production, and evaluation of renewable hydrogen production capacities show that Gilangharb has the highest capacity among the studied cities.

• Structural Monitoring and Maintenance
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• 제1권3호
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• pp.249-271
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• 2014

This paper presents a unique study of Structural Health Monitoring (SHM) for the maintenance decision making about a real life movable bridge. The mechanical components of movable bridges are maintained on a scheduled basis. However, it is desired to have a condition-based maintenance by taking advantage of SHM. The main objective is to track the operation of a gearbox and a rack-pinion/open gear assembly, which are critical parts of bascule type movable bridges. Maintenance needs that may lead to major damage to these components needs to be identified and diagnosed timely since an early detection of faults may help avoid unexpected bridge closures or costly repairs. The fault prediction of the gearbox and rack-pinion/open gear is carried out using two types of Artificial Neural Networks (ANNs): 1) Multi-Layer Perceptron Neural Networks (MLP-NNs) and 2) Fuzzy Neural Networks (FNNs). Monitoring data is collected during regular opening and closing of the bridge as well as during artificially induced reversible damage conditions. Several statistical parameters are extracted from the time-domain vibration signals as characteristic features to be fed to the ANNs for constructing the MLP-NNs and FNNs independently. The required training and testing sets are obtained by processing the acceleration data for both damaged and undamaged condition of the aforementioned mechanical components. The performances of the developed ANNs are first evaluated using unseen test sets. Second, the selected networks are used for long-term condition evaluation of the rack-pinion/open gear of the movable bridge. It is shown that the vibration monitoring data with selected statistical parameters and particular network architectures give successful results to predict the undamaged and damaged condition of the bridge. It is also observed that the MLP-NNs performed better than the FNNs in the presented case. The successful results indicate that ANNs are promising tools for maintenance monitoring of movable bridge components and it is also shown that the ANN results can be employed in simple approach for day-to-day operation and maintenance of movable bridges.

• 한국컴퓨터정보학회논문지
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• 제11권3호
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• pp.1-10
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• 2006

서비스를 요구하는 다수의 사용자를 수용하려면 마이크로-와 피코-셀과 같은 작은 셀로 크기를 더욱 줄이는 것이 일반적으로 수용되고 있다. 이런 환경에서는 빈번한 핸드오버가 발생하게 되고 이로 인해 허용 가능한 핸드오버 처리 지연 시간을 감소시켜 결국 패킷 손실과 핸드오버 실패를 초래하게 된다는 것이다. 또한 패킷 손실을 보상하기 위한 재전송이 필요하게 되어 시스템의 성능을 저하시킨다. 본 논문에서는 차세대이동통신시스템을 위한 새로운 핸드오버 기법을 제시한다. 이동 단말기의 현재 위치와 이동 방향을 기반으로 핸드오버 셀을 예측함으로서, 핸드오버 설정 절차가 핸드오버 요청 전에 선행된다. 시뮬레이션은 핸드오버 실패율과 패킷 손실율에 초점을 두었다. 시뮬레이션 결과를 통하여 제시된 방안이 기존의 방법보다 향상된 성능을 보임을 입증한다.

• 디지털융복합연구
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• 제15권7호
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• pp.97-109
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• 2017

국내 자동차 보급률은 매년 3%대로 성장하고 있으나 꾸준한 가격인상으로 중고자동차를 구매하는 소비자가 늘고 있다. 그럼에도 불구하고 중고차 수출시장은 최근 주요국가의 수입 규제와 수출단지의 낙후된 환경 등으로 인해 하락세가 예상되고 있는 실정이다. 따라서 본 연구는 Fuzzy-AHP를 통해 새롭게 조성하는 인천항 중고자동차 물류단지에 대한 운영 요인을 도출하여 현실적인 운영방안을 제시하고자 하였다. Fuzzy-AHP는 각 계층 속성의 중요도를 산출하고 인간의 언어적인 모호함을 퍼지 수로 변환하는 방법론으로 현실적인 의사결정 방안을 제시할 수 있다. 운영요인 분석 결과 대요인에서는 물류단지비용요인이 가중치 0.306을 기록하여 가장 중요한 요인으로 도출되었으며 세부요인은 단지임대료, 단지 접근성, 물류부지규모 순으로 높게 나타났다. 선진화된 중고자동차 물류단지를 위해 경쟁력 있는 임대료 산정이 필요하며 임대료 지원 정책 실현 및 자유무역지구 지정을 고려해야한다 또한 해외 바이어를 위한 접근 인프라 확충 및 단지규모 확보가 필요하며 정부 차원의 전반적인 제도 개선 및 미래를 위한 IT 시스템의 도입이 필요하다.

• 전자공학회논문지CI
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• 제48권4호
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• pp.51-60
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• 2011

무선 환경에서의 인증 모델은 많은 보안 위험을 내포하고 있다. 그러나 이 분야에 일반적으로 사용되는 표준 기술이 존재하는 것이 아니어서 본 논문에서는 무선 인증 환경에서 보다 강화된 보안을 제시할 수 있는 퍼지 논리 기반의 인증 모델을 제시한다. 제안하는 모델을 위해서 퍼지 논리 기반의 분류 방법을 사용하고 적절한 판단을 위해서 개선된AHP 알고리즘과 사례 기반의 추론 방법을 추가적으로 사용한다. 개선된AHP 알고리즘을 사용해서 다양한 상황정보를 수치화하고, 제안된 인증 모델을 사용해서 입력 데이터에 대한 보안 등급을 계산한 다음, 다양한 환경의 상황정보를 가진 무선환경에 제안된 인증 모델을 안정적으로 사용할 수 있을 것이다. 향후에는 상황인식 연구를 클라우드 컴퓨팅 분야를 포함한 다양한 분야로 제안 모델을 확대하면 더욱 안전한 보안 환경을 기대할 수 있을 것이다.

• 한국환경보건학회지
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• 제42권5호
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• pp.302-313
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• 2016

Objectives: This study was conducted to assess environmental health status on a local scale using environmental health-related indicators. It demonstrated the possibility of using a structural equation model, a methodological approach to provide synthesized information. Methods: Eighteen indicators were selected from official statistical data published by local governments. Each environmental health-related indicator was classified according to the PSR (pressure-state-response) model. Aggregation methods were performed using principal component analysis and fuzzy sets. Results: The five principal components were classified through principal component analysis (PCA) and obtained eigenvalues >1.0 from the initial 18 indicators. The aggregated index was obtained by condensing the original information into two broad and simple categories through fuzzy sets. Conclusion: This could be useful in that the aggregation procedure may provide a basis for establishing environmental health policies and a decision-making process. However, the availability and quality of indicators, assessment of aggregation method bias, choice of weighted scores for indicators, and other factors should be examined in future studies.