• Journal of the Korean Society of Safety
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• v.30 no.4
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• pp.151-158
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• 2015

Usually risk assessment is performed for the safety of diverse industries though, many kinds of risks cannot be analyzed effectively by using classical probability models due to lack of experience data and impreciseness of human decision making. For these reasons, fuzzy risk assessment utilizing subjective judgment and experience of skillful experts has been considered as a solution. In this study, to comprehend the relationship between conventional fuzzy theory and human conceptual images on risks, linguistic variables were reviewed with reference to fuzzy membership functions, especially in the Korean language. As interviewees, about a hundred people including students as well as safety engineers voluntarily participated. The research results showed that most people were in favor of adjective expressions decorated with adverbs rather than naive expressions such as "high" or "low", and that directly translated linguistic variables were not appropriate for the Korean people in risk assessment as far. Therefore, with consideration of the selection tendency by the Korean people in linguistic variables, it could be concluded that 5 level expressions would be most favorable for linguistic variables in risk assessments in Korea.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.7
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• pp.1351-1362
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• 1992

Qualitative models in model-based expert system needs modeling paradigm which provides intelligent control of modeling assumptions and extracts robust inferences without quantitative information about the system to be modeled. Qualitative reasoning methodologies has proved the property of the completeness but not the soundness to the corresponding quantitative model. We propose new methodology of qualitative reasoning by introducing the concept of Centroid-Oriented Composite Interval to improve the soundness problem. Arithmetic operations and equivalence classes were composed using this definition. Qualitative simulation results were compared to Kuipers's results and the improvements in the soundness problem is verified.

• Journal of the Korean Society of Safety
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• v.31 no.4
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• pp.120-125
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• 2016

Usually, a risk can be expressed as a product of likelihood and consequence of a hazard factor. Therefore, conventional risk assessment is carried out by frequency analysis and severity analysis, in turns. However, it is well known that intuitive thinking is another excellent way of thinking of human beings. This study aimed to confirm whether there exist any difference in risk assessment results derived by two different procedures - intuitive and analytical. Thus, the present study showed 10 different illustrations to 30 undergraduate students. Their responses were organized as fuzzy membership functions, and summarized as risk assessments, and compared. The results were also verified with the help of statistical hypothesis testing, which showed no significant difference. On the contrary, however, similarity measure used in fuzzy set theory was not credible as anticipated. Many cases failed to satisfy statistical hypothesis even with similarity measure higher than 0.60 so that only a trend could be accepted. In addition, a subject showed a somewhat consistent logical discrepancy in his response, which implied the necessity of sincere analysis in fuzzy formulations.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.65-67
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• 1996

This paper presents the automatic construction and parameter optimization technique for the fuzzy logic controller using genetic algorithm. In general the design of fuzzy controller has difficulties in the acquisition of expert's knowledge and relies to a great extent on empirical and heuristic knowledge which, in many cases, cannot be objectively justified. Therefor the performance of the controller can be degraded in the case of plant parameter variations or unpredictable incident which the designer may lave ignored. And fuzzy logic controller parameters elicited form the expert may not be global. Some of these problems can be resolved by application of genetic algorithm. Finally, we provides the second order dead time plant to evaluate the feasibility and generality of our proposed method. Comparison shows that the proposed method can produce a fuzzy logic controller with higher accuracy and a smaller number of fuzzy roles than manually billed fuzzy logic controller.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.34-34
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• 2022

우리나라의 하천은 그 중요도와 규모에 따라 국가·지방·소하천 및 세천 등으로 분류하고 있다. 우리나라 하천 관리는 주로 국가 지방하천을 중심으로 이루어지고 있다. 특히 수리량 계측에 있어서 대부분의 수위 유량 관측시설이 국가 지방하천에 위치해 있으며, 소하천에 대한 관측은 거의 이루어 지지 않고 있다. 이로 인해 소하천 설계기준의 홍수량 산정 공식은 국내 중규모 이상 하천의 경험식이나 외국의 소하천 경험식에 기반한 매개변수를 따르고 있어, 국내 소하천의 특성을 반영하지 못하고 있다. 국립재난안전연구원에서는 국내 소하천 특성에 적합한 설계기준 개발 및 홍수량 산정을 위해 소하천 자동유량계측기술을 개발하고, 전국 소하천의 10%(2,230개소)에 설치·운영하는 것을 목표로 행정안전부 및 지자체와 협력하여 확대 구축을 추진 중이다. 소하천은 유로연장이 짧고 유역면적이 크지 않아 도달시간이 짧은 것이 특징으로, 강우-유량 노모그래프를 사용하여 소하천 홍수 예·경보를 위한 홍수량 산정이 가능하다. 강우-유량 관계는 선행강우에 따른 토양의 포화상태와 강우 발생 시점의 기저유량 등에 영향을 많이 받는다. 본 연구에서는 자동유량계측기술 설치 시범소하천 5개소의 계측데이터를 사용하여 선행강우를 고려한 강우-유량 노모그래프를 개발하였다. 또한, 뉴로-퍼지 기법과 회귀분석을 사용한 홍수량 예측결과와 비교 연구를 수행하였다.

• Journal of the Korean Regional Science Association
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• v.34 no.4
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• pp.3-18
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• 2018

These days, regional innovation draws more attention than ever as a growth engine for regional economies, and governments put a variety of efforts to establish Regional Innovation systems(RISs). In this circumstance, this study aims to analyze types of RISs and the combinations of the factors influencing innovation performance as measured by patent application. Most of previous works have depended on case-oriented or variable-oriented strategy to classify types of RISs or to analyze the effects on performance of innovation factors, having some limitations: Variable-oriented approaches fail to capture complex combinatory effects of factors, while case-oriented approaches tend to depend on subjective interpretation. This study made use of the recently proposed fs/QCA(Fuzzy-set Qualitative Comparative Analysis) to overcome the limitations of those strategies. Based on the theory of RIS, three factors for regional innovation-input, infrastructure, and network-are used to classify 16 Korean Provinces. The results show that eight types of regional innovation types are identified, and that most of the regions are classified into either IN-type, equipped with high levels of Input and Network, or F-type, with high levels of infrastructure. In addition, applying seven sub-variables of the three factors to the fussy-set combination factor analysis, we examine a combination of factors influencing patent application. The results show that regions with high levels of R&D expense, valid patent, industry-academia cooperation, IP budget, and TLO values, and low IP capital almost always have a high level of patent application. Therefore, for regional innovation, the public sector needs to provide institutional support for R & D personnel training. It is also important to for both the public and the private sectors to make efforts to stimulate IP financing.

• Journal of Intelligence and Information Systems
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• v.12 no.1
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• pp.17-31
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• 2006

In this paper, passport recognition and face verification methods which can automatically recognize passport codes and discriminate forgery passports to improve efficiency and systematic control of immigration management are proposed. Adjusting the slant is very important for recognition of characters and face verification since slanted passport images can bring various unwanted effects to the recognition of individual codes and faces. Therefore, after smearing the passport image, the longest extracted string of characters is selected. The angle adjustment can be conducted by using the slant of the straight and horizontal line that connects the center of thickness between left and right parts of the string. Extracting passport codes is done by Sobel operator, horizontal smearing, and 8-neighborhood contour tracking algorithm. The string of codes can be transformed into binary format by applying repeating binary method to the area of the extracted passport code strings. The string codes are restored by applying CDM mask to the binary string area and individual codes are extracted by 8-neighborhood contour tracking algerian. The proposed RBF network is applied to the middle layer of RBF network by using the fuzzy logic connection operator and proposing the enhanced fuzzy ART algorithm that dynamically controls the vigilance parameter. The face is authenticated by measuring the similarity between the feature vector of the facial image from the passport and feature vector of the facial image from the database that is constructed with PCA algorithm. After several tests using a forged passport and the passport with slanted images, the proposed method was proven to be effective in recognizing passport codes and verifying facial images.

• The Journal of Engineering Geology
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• v.20 no.3
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• pp.243-255
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• 2010

The slope design of an open-pit mine must consider economical efficiency and stability. Thus, the overall slope angle is the principal factor because of limited support or reinforcement options available in such a setting. In this study, slope displacement, as monitored by a GPS system, was analyzed for a coal mine at Pasir, Indonesia. Predictions of failure time by inverse velocity analysis showed good agreement with field observations. Therefore, the failure time of an unstable slope can be roughly estimated prior to failure. A GIS model that combines fuzzy theory and the analytical hierarchy process (AHP) was developed to assess slope instability in open-pit coal mines. This model simultaneously considers seven factors that influence the instability of open-pit slopes (i.e., overall slope gradient, slope height, surface flows, excavation plan, tension cracks, faults, and water body). Application of the proposed method to an open-pit coal mine revealed an enhanced prediction accuracy of failure time and failure site compared with existing methods.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.777-783
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• 2004

하천 세내지 주변은 급속한 시가지 조성과 인구밀집으로 유역의 불투수층이 증가하여 홍수도달시간이 짧아지고 홍수유출량이 증가하고 있다. 또한 엘리뇨${\cdot}$라니냐 등의 이상기후로 홍수사상의 발생 빈도와 규모가 증가하면서 홍수피해도 대형화되어 가고 있다. 그러나 치수사업은 다른 공공사업에 비해 경제성이 저평가 되어 투자우선순위가 밀려 사업시행이 지연되고 예방적 차원의 대책도 미흡하여 피해가 증가하는 악순환이 계속되고 있다. 따라서 본 인구에서는 우리나라의 치수경제성 분석에 있어 계량화하지 못하고 있는 자산이용고도화 효과를 치수안전도와 더불어 분석하고자 한다. 자산이용고도화는 치수사업 시행으로 해당지역의 치수안전도 향상에 따른 자산가치의 상승을 말하는데, 특정지역의 자산가치를 가장 객관적으로 표현할 수 있는 공시지가를 근거로 분석을 수행하였다. 치수사업 시행으로 인한 편익과 하천 특성에 따른 지가변동률의 차이가 통계적으로 유의성이 있는지를 분산분석을 통해 검증하였으면, 자산가치의 상승을 순수 연평균지가변동률로 나타내었다. 치수안전도는 홍수피해 잠재성과 홍수방어능력으로 구분하였는데 홍수피해 잠재성은 도시화율에 따라 구분하였고, 홍수방어능력은 홍수량의 빈도해석과 불확실성을 고려하여 조건부 비초과확률로 나타내었다. 본 연구에서는 소도시 지역(경안천, 복하천, 청미천)을 대상으로 200년 빈도의 홍수사상에 내해 10년, 50년 설계빈도로 건설된 제방의 조건부 비초과확률을 산정하여 지가변동률의 추이를 비교 분석하였다. 분석 결과, 소도시 지역에서는 조건부 비초과확률이 $10\%$ 상승했을 때 순수 연평균지가변동률이 5배정도 상승함을 알 수 있었다.다시 입력자료로 사용하는 업데이트 방식을 사용하기 때문에 예측결과의 오차가 완전하게 보정되지 않으면 다음 결과에 역시 오차를 주게 되어 오차보정이 상당히 중요하다는 것을 알 수 있었다. 오차를 보다 효과적으로 보정하기 위해서는 퍼지제어에 사용되는 퍼지규칙의 수를 늘리고, 유입량에 직접적인 영향을 주는 강우량과 연계한 2변수의 Fuzzy-Grey 모형을 이용한다면 보다 정확한 유입량 예측이 가능할 것으로 사료된다.이 작은 오차를 발생하였으며, 전체적으로 퍼프 모형이 입자모형보다는 훨씬 적은 수의 계산을 통해서도 작은 오차를 나타낼 수 있다는 것을 알 수 있었다. 그러나 Gaussian 분포를 갖는 퍼프모형은 전단흐름에서의 긴 유선형 농도분포를 모의할 수 없었고, 이에 관한 오차는 전단계수가 증가함에 따라 비선형적으로 증가하였다. 향후, 보다 다양한 흐름영역에서 장${\cdot}$단점 분석 및 오차해석을 수행한 후에 각각의 Lagrangian 모형의 장점만을 갖는 모형결합 방법을 제시할 수 있을 것으로 판단된다.mm/$m^{2}$로 감소한 소견을 보였다. 승모판 성형술은 전 승모판엽 탈출증이 있는 두 환아에서 동시에 시행하였다. 수술 후 1년 내 시행한 심초음파에서 모든 환아에서 단지 경등도 이하의 승모판 폐쇄 부전 소견을 보였다. 수술 후 조기 사망은 없었으며, 합병증으로는 유미흉이 한 명에서 있었다. 술 후 10개월째 허혈성 확장성 심근증이 호전되지 않아 Dor 술식을 시행한 후 사망한 예를 제외한 나머지 6명은 특이 증상 없이 정상 생활 중이다 결론: 좌관상동맥 페동맥이상 기시증은 드물기는 하나, 영유아기에 심근경색 및 허혈성 심근증 또는 선천성 승모

• Korean Journal of Social Welfare Studies
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• v.48 no.2
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• pp.71-95
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• 2017

This study aims (1) to identify whether real terms of imprisonment for sexual offenders against children are different between the first trial and appeal trial in 16 cases and (2) to assess which sentencing factors such as history of sexual crime of perpetrator, forgiveness of children, regretfulness of perpetrator, power of perpetrator, and relationship of perpetrator and victim influence sentencing period of imprisonment in the first and appeal trials, respectively. This study used cases which were prosecuted for sexual crimes against children since the protection act on the children and juveniles from sexual abuse was enacted in 2000. The target cases of the study include 8 first trials and 8 appeal cases which were appealed to the Supreme Court between 2000 and 2015. Result condition is the real term of imprisonment. Cause conditions include sentencing factors such as history of sexual crime, regretfulness, and power of perpetrator, forgiveness of child, and relationship between offender and victim. We employed Qualitative Comparative Analysis (QCA) for data analysis. We found that there are sentences in the first trial with lower terms than appeal trial regarding child sexual crimes. In addition, we found that (1) power of perpetrator and forgiveness of victim significantly influenced sentencing periods of imprisonment at levels of courts; (2) cause condition considered as comparatively more important in the first trial was regretfulness of perpetrator(but not in the appeal trial); and (3) relationship of perpetrator and child was not important in sentencing for sexual crime at both levels of trials.