• 대한인간공학회지
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• 제35권4호
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• pp.263-275
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• 2016

Objective: This paper introduces the regulatory oversight approaches and issues to consider in the course of safety culture oversight model development in the nuclear field. Common understanding on regulatory oversight and present practices of international communities are briefly reviewed. The nuclear safety culture oversight model of Korea is explained focusing on the development of safety culture definition and components, and their basic meanings. Oversight components are identified to represent the multiple human and organizational elements which can affect and reinforce elements of defense in depth system for nuclear safety. Result of validation study on safety culture components is briefly introduced too. Finally, the results of the application of the model are presented to show its effectiveness and feasibility. Background: The oversight of nuclear licensee's safety culture has been an important regulatory issue in the international community of nuclear safety regulation. Concurrent with the significant events that started to occur in the early 2000s and that had implications about safety culture of the operating organizations, it has been natural for regulators to pay attention to appropriate methods and even philosophy for intervening the licensee's safety culture. Although safety culture has been emphasized for last 30 years as a prerequisite to ensure high level of nuclear safety, it has not been of regulatory scope and has a unique dilemma between external oversight and the voluntary nature of culture. Safety culture oversight is a new regulatory challenge that needs to be approached taking into consideration of the uncontrollable aspects of cultural changes and the impacts on licensee's safety culture. Although researchers and industrial practitioners still struggle with measuring, evaluating, managing and changing safety culture, it was recognized that efforts to observe and influence licensees' safety culture should not be delayed. Method: Safety culture components which regulatory oversight will have to focus on are developed by benchmarking the concept of physical barriers and introducing the defense in depth philosophy into organizational system. Therefore, this paper begins with review of international regulatory oversight approaches and issues associated with the regulatory oversight of safety culture, followed by the development of oversight model. The validity of the model was verified by statistical analysis with the survey result obtained from survey administration to NPP employees in Korea. The developed safety culture oversight model and components were used in the "safety culture inspection" activities of the Korean regulatory body. Results: The developed safety culture model was confirmed to be valid in terms of content, construct and criterion validity. And the actual applicability in the nuclear operating organization was verified after series of pilot "safety culture inspection" activities. Conclusion: The application of the nuclear safety culture oversight model to operating organization of NPPs showed promising results for regulatory tools required for the organizations to improve their safety culture. Application: The developed oversight model and components might be used in the inspection activities and regulatory oversight of NPP operating organization's safety culture.

• Communications for Statistical Applications and Methods
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• 제15권5호
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• pp.697-708
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• 2008

본 논문은 금융기관에서 활용하고 있는 운영리스크 측정모형에 대한 적합성검증 방법 중 안정성 검증에 관한 것이다. 신용리스크와는 달리 운영리스크는 손실자료의 특징, 과거 자료의 부족 그리고 적합성검증을 위한 이론적 도구의 부족 등으로 인해 현재 적절한 적합성검증 방안에 제시되지 못하고 있다. 본 논문에서는 운영리스크 VaR(Value at Risk) 추정값의 안정성을 평가하는 적합성검증 방법을 제시하고 이를 활용한 실증분석을 통해 제안된 방법에 대한 실제적 활용 가능성을 확인해 보고자 한다. 구체적으로 본 논문에서는 붓스트랩 방법을 활용하여 운영리스크 VaR의 신뢰구간을 생성함으로써 운영리스크 VaR 추정값의 안정성을 검증하는 기법을 제안하였으며, 이를 토대로 적합에 따른 운영리스크 VaR 추정값의 안정성을 측정하는 방안도 제시하였다.

• 한국과학교육학회지
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• 제34권8호
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• pp.745-754
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• 2014

본 연구의 목적은 한국 중학생들이 과학을 학습하는 과정에서 경험하는 성취정서를 측정하기 위한 질문지를 개발하고 그 타당성을 검증하는 것이다. 본 연구에서 개발한 한국 중학생의 과학영역 성취정서 질문지는 영어판 성취정서 질문지를 바탕으로 중학교 교과 운영 특성 및 과학 학습의 특징을 반영하여 개발되었다. 총 232문항으로 3가지 학업상황에서 9개의 과학 영역 성취정서를 측정하도록 구성되어 있으면 통제-가치 이론에 근거를 두고 있다. 검증 결과, 높은 신뢰도를 보였으며, 성취정서의 4가지 구성요인 체계를 확인하기 위한 확인적 요인분석(CFA) 결과, 질문지의 각 문항이 성취정서의 구성 요인을 대표하는 지표로서 적절히 구성되어 있었으며 구조적으로 타당하였다. 또한 질문지를 통하여 측정되는 성취정서들 사이의 상관관계를 분석한 결과, 같은 상황에서 경험하는 각각의 정서 및 서로 다른 상황에서 경험하는 동일한 정서가 서로 적절히 변별 되었다. 성취정서와 학업상황 사이의 잠재적 관계에 대한 확인적 요인 분석 결과에서도 질문지의 내적 구조와 동일하게 3가지 학업상황 및 9가지 성취정서가 잠재변수로서 작용하고 있음을 확인하였다. 외적 타당도 검증은 통제-가치 평가, 학습 전략, 성취동기, 과학 성적 등을 준거 변인으로 하여 실시하였으며 검증 결과, 충분한 외적 타당도를 가지고 있는 것으로 나타났다. 본 연구 결과는 정량적으로 분석할 수 있는 질문지의 개발을 통해 중학교 과학 교과에서 학생들이 경험하는 성취정서를 이해하는 기본 발판이 마련되었음을 시사한다.

• Journal of Platform Technology
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• 제9권1호
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• pp.15-22
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• 2021

In a smart manufacturing environment, more and more devices are connected to the Internet so that a large volume of data can be obtained during all phases of the product life cycle. The large-scale industries, companies and organizations that have more operational units scattered among the various geographical locations face a huge resource consumption because of their unorganized structure of sharing resources among themselves that directly affects the supply chain of the corresponding concerns. Cloud-based smart manufacturing paradigm facilitates a new variety of applications and services to analyze a large volume of data and enable large-scale manufacturing collaboration. The manufacturing units include machinery that may be situated in different geological areas and process instances that are executed from different machinery data should be constantly managed by the super admin to coordinate the manufacturing process in the large-scale industries these environments make the manufacturing process a tedious work to maintain the efficiency of the production unit. The data from all these instances should be monitored to maintain the integrity of the manufacturing service system, all these data are computed in the cloud environment which leads to the latency in the performance of the smart manufacturing service system. Instead, validating data from the external device, we propose to validate the data at the front-end of each device. The validation process can be automated by script validation and then the processed data will be sent to the cloud processing and storing unit. Along with the end-device data validation we will implement the APM(Asset Performance Management) to enhance the productive functionality of the manufacturers. The manufacturing service system will be chunked into modules based on the functionalities of the machines and process instances corresponding to the time schedules of the respective machines. On breaking the whole system into chunks of modules and further divisions as required we can reduce the data loss or data mismatch due to the processing of data from the instances that may be down for maintenance or malfunction ties of the machinery. This will help the admin to trace the individual domains of the smart manufacturing service system that needs attention for error recovery among the various process instances from different machines that operate on the various conditions. This helps in reducing the latency, which in turn increases the efficiency of the whole system

• 한국전산유체공학회지
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• 제13권2호
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• pp.48-54
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• 2008

COMS (Communication, Ocean and Meteorological Satellite) is a geostationary satellite and has been developing by KARI for communication, ocean and meteorological observations. It will be launched by ARIANE 5. Ka-band components are installed on South panel, where single solar array wing is mounted. Radiators, embedded heat pipes, external heat pipe, insulation blankets and heaters are utilized for the thermal control of the satellite. The Ka-band payload section is divided several areas based on unit operating temperature in order to optimize radiator area and maximize heat rejection capability. Other equipment for sensors and bus are installed on North panel. The ocean and meteorological sensors are installed on optical benches on the top floor to decouple thermally from the satellite. During the transfer orbit operation, satellite will be under severe thermal environments due to low dissipation of components, satellite attitudes and LAE(Liquid Apogee Engine) firing. This paper presents temperature and heater power prediction and validation of thermal control design during transfer orbit operation.

• Journal of Ginseng Research
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• 제37권3호
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• pp.341-348
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• 2013

Identification of the origins of Panax ginseng has been issued in Korea scientifically and economically. We describe a metabolomics approach used for discrimination and prediction of ginseng roots from different origins in Korea. The fresh ginseng roots from six ginseng cooperative associations (Gangwon, Gaeseong, Punggi, Chungbuk, Jeonbuk, and Anseong) were analyzed by UPLC-MS-based approach combined with orthogonal projections to latent structure-discriminant analysis multivariate analysis. The ginsengs from Gangwon and Gaeseong were easily differentiated. We further analyzed the metabolomics results in subgroups. Punggi, Chungbuk, Jeonbuk, and Anseong ginseng could be easily differentiated by the first two orthogonal components. As a validation of the discrimination model, we performed blind prediction tests of sample origins using an external test set. Our model predicted their geographical origins as 99.7% probability. The robust discriminatory power and statistical validity of our method suggest its general applicability for determining the origins of P. ginseng samples.

• Journal of the Korean Data and Information Science Society
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• 제27권2호
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• pp.275-284
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• 2016

정확한 전력수요 예측은 에너지 소비를 줄이고 전력수급의 불균형을 방지한다. 본 연구는 외부요인의 영향을 가장 적게 받는 특정 시간대의 일 단위 전력 수요량을 참조선 (reference line)으로 한 시계열모형을 세우고자 한다. 고려된 시계열모형은 슬라이딩 창을 이용한 이중 계절성 Holt-Winters 모형과 TBATS 모형이다. 시계열모형의 모수는 2009년 1월 4일부터 2011년 12월 31일까지 자료를 이용하여 추정되었으며, 2012년 1월 1일부터 2012년 12월 29일까지의 각 모형의 전력수요량을 예측하여 성능을 비교하였다. RMSE와 MAPE를 통해 예측 성능을 비교한 결과 TBATS 모형의 성능이 우수하였다.

• 한국경영과학회지
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• 제34권3호
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• pp.1-27
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• 2009

Since online knowledge networks usually consist of a larger, loosely knit, and geographically distributed group of "strangers" who may not know each other very well, members may not willingly share their knowledge with others. In order to address this challenge, this study looks Into the factors that are expected to affect knowledge sharing in an online knowledge network. For empirical validation, we choose "the global network of Korean scientists and engineers (KOSEN)" as one of the best practices of online knowledge networks. By using the archival, network, and survey data, we validate two models of knowledge sharing in sequence (i.e., knowledge contribution and knowledge utilization models) and then discuss the results. The findings of this study show that individuals not only contribute but also utilize knowledge in an online knowledge network when they are structurally embedded and perceive a strong reciprocity. In the network. In addition, taking pleasure in helping is found to positively affect knowledge contribution, whereas perceiving usefulness is found to Influence knowledge utilization. Contributions of this study and future research opportunities are also discussed.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.2154-2161
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• 2014

Growth analysis and selection of sea cucumbers (Stichopus japonicas) is typically performed through length or weight measurements. However, because sea cucumbers continuously change shape depending on the external environment, weight measurement has been the preferred approach. Weight measurements require extensive time and labor, moreover it is often difficult to accurately weigh sea cucumbers because of their wet surface. The present study measured sea cucumber features, including the body length, width, and thickness, by using a vision system and regression analysis to generate $R^2$ values that were used to develop a weight estimation algorithm. The $R^2$ value between the actual volume and weight of the sea cucumbers was 0.999, which was relatively high. Evaluation of the performance of this algorithm using cross-validation showed that the root mean square error and worst-case prediction error were 1.434 g and ${\pm}5.879g$, respectively. In addition, the present study confirmed that the proposed weight estimation algorithm and single slide rail device for weight measurement can measure weights at approximately 4,500 sea cucumbers per hour.

• Structural Engineering and Mechanics
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• 제38권1호
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• pp.1-25
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• 2011

A new nonlinear model was developed to evaluate the shear resistance of steel fiber-reinforced concrete beams (SFRCB) using linear genetic programming (LGP). The proposed model relates the shear strength to the geometrical and mechanical properties of SFRCB. The best model was selected after developing and controlling several models with different combinations of the influencing parameters. The models were developed using a comprehensive database containing 213 test results of SFRC beams without stirrups obtained through an extensive literature review. The database includes experimental results for normal and high-strength concrete beams. To verify the applicability of the proposed model, it was employed to estimate the shear strength of a part of test results that were not included in the modeling process. The external validation of the model was further verified using several statistical criteria recommended by researchers. The contributions of the parameters affecting the shear strength were evaluated through a sensitivity analysis. The results indicate that the LGP model gives precise estimates of the shear strength of SFRCB. The prediction performance of the model is significantly better than several solutions found in the literature. The LGP-based design equation is remarkably straightforward and useful for pre-design applications.