• Title/Summary/Keyword: uncertain data

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Sequential Bayesian Updating Module of Input Parameter Distributions for More Reliable Probabilistic Safety Assessment of HLW Radioactive Repository (고준위 방사성 폐기물 처분장 확률론적 안전성평가 신뢰도 제고를 위한 입력 파라미터 연속 베이지안 업데이팅 모듈 개발)

  • Lee, Youn-Myoung;Cho, Dong-Keun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.18 no.2
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    • pp.179-194
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    • 2020
  • A Bayesian approach was introduced to improve the belief of prior distributions of input parameters for the probabilistic safety assessment of radioactive waste repository. A GoldSim-based module was developed using the Markov chain Monte Carlo algorithm and implemented through GSTSPA (GoldSim Total System Performance Assessment), a GoldSim template for generic/site-specific safety assessment of the radioactive repository system. In this study, sequential Bayesian updating of prior distributions was comprehensively explained and used as a basis to conduct a reliable safety assessment of the repository. The prior distribution to three sequential posterior distributions for several selected parameters associated with nuclide transport in the fractured rock medium was updated with assumed likelihood functions. The process was demonstrated through a probabilistic safety assessment of the conceptual repository for illustrative purposes. Through this study, it was shown that insufficient observed data could enhance the belief of prior distributions for input parameter values commonly available, which are usually uncertain. This is particularly applicable for nuclide behavior in and around the repository system, which typically exhibited a long time span and wide modeling domain.

Surgical Treatment of the Descending Thoracic Aorta ; An analysis of 22 cases (하행 흉부 대동맥류의 외과적 치료; 22예의 분석)

  • 이홍섭;이선훈;윤영철;구본일;김창호
    • Journal of Chest Surgery
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    • v.32 no.6
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    • pp.532-535
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    • 1999
  • Background: The purpose of this study was to evaluate and analyze the surgical techniques and postoperative complications in patients undergoing operations for descending thoracic aortic aneurysms. Material and Method: The data of 22 major operations between March 1987 and August 1997 were retrospectively reviewed. Result: There were 18 men and 4 women with a mean age of 49 years (range 33 years to 82 years). The cause of the aneurysm was aortic dissection in 13 patients, atherosclerosis in 3, mycotic in 3, trauma in 2 and uncertain in 1. The operative techniques were resection and graft replacement in 16, axillofemoral bypass graft in 2, femorofemoral bypass graft in 2, exclusion, aneurysmorrhaphy in 1 and transfemoral stent insertion in 1. During the operation, 16 cases were performed under total aortic clamp. Among the 16 patients, femorofemoral bypass was used in 14 cases and previously made shunt in 2 cases. The mean total aortic clamp time was 91 minutes and the mean extracorporeal circulation time was 116 minutes. One death occurred in an excluded patient on the 52 postoperative day due to a rupture of the aneurysm. Postoperative complications were paraplegia in 1 case, acute renal failure in 1 case and acute respiratory failure in 1 case. Conclusion: Although surgical treatment of the descending thoracic aneurysm has many postoperative complications, good surgical results can be achieved with a proper patient selection and fine surgical techniques.

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A Study on the Application of the Technology Tree for Water Hazard Information Platform (수재해 정보 플랫폼을 위한 기술트리 활용 방안 연구)

  • Kim, Dong-Young;Lee, Jeong-Ju;Chae, Hyo-Sok;Hwang, Eui-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.4
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    • pp.200-214
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    • 2014
  • Technology planning is becoming increasingly important with the rapid development and decline of technology. Technology roadmapping is a tool used to select whether the specific technique of technology planning should pursue which technology and in which time. This technology is important to secure the uncertain future since it will provide a method that is able to share the goals and strategies between organizations. Therefore, technology tree in the planning stage of the problem would be a very useful tool. In this study, both domestic and international technology tree application cases were analyzed to be able to derive a plan for ensuring that the research performed and the requirements are met for the future development and implementation of a convergence portal system. The six major systems that aim at water hazard information platform are basic information providing system, analysis information providing system, water disaster theme providing system, national disaster information system, water disaster augmented reality system and open information platform system. General standardized core technologies corresponding to the needed functions in each target system are derived through brainstorming, and classified according to the technology field to derive the technology tree.

A Study on Improvement of Handling Dirty Bulk Cargo in Busan Port (부산항의 기피화물 취급 개선에 관한 연구)

  • Song, Gye-Eui
    • Journal of Korea Port Economic Association
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    • v.26 no.3
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    • pp.114-129
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    • 2010
  • Busan port's main function is handling container cargo compared to world major ports and the percentage of handling general cargo such as dirty bulk cargo is very low. In other words, although total cargo weight of Busan port that recorded the handling result of 13.29million TEU in 2008 reached 113.05million ton, total cargo weight of general cargo was 15.31million ton, so container cargo accounted for 88.1% of whole cargo weight. However, it is the time to create high added value by the increase of handling and marketing dirty bulk cargo. Originally, the dirty bulk cargo was not the avoided object from the first. Somehow, it is a very high added value cargo, and is surely essential strategic material to basic industries of nation. However, it becomes dirty bulk cargo as the companies are reluctant to handle it because of environmental problem, distinct characteristic in handling, uncertain break even point due to imbalance between supply and demand compared to container cargo. However, items that are classified as dirty bulk cargo now are certainly necessary strategic materials to national basic industries or national life. Besides it seems to be a high added value cargo here and now. Therefore, it is time that increasing of handling dirty bulk cargo by marketing it and the system for efficient handling such as constructing the exclusive use wharf in Busan port, modernizing of facilities and equipments, stable secure of place for holding and handling through development of distribution complex by item, efficient data processing and closer cooperation by setting up a SCM of related authorities are needful.

A Qualitative Study on the Community Participation Experiences of Married Immigrant Women in Rural Areas (농촌지역 결혼이주여성의 지역사회활동 참여경험에 관한 질적 연구)

  • Lee, Hyoung-Ha
    • Korean Journal of Social Welfare
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    • v.62 no.3
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    • pp.219-245
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    • 2010
  • The objective of this study is to identify the community living experiences of married immigrant women in rural areas. For this purpose, we conducted qualitative research by sampling 14 married immigrant women who had lived in Korea for over three years by having in depth interviews with them. This study employed the grounded theory method suggested by Strauss and Corbin(1998). When raw data from in depth interviews with the participants were processed by open coding through the continuous comparison method with theoretical sensitivity, a total of 13 categories, 27 sub.categories, and 71 concepts were extracted. In case of axial coding, according to the results of analyzing through the paradigm procedure, the causal conditions for the community living experiences of married immigrant women in rural areas were 'Uncertain start' and 'Confront practical problems,' and the central phenomenon was 'Search for existence to participate in community activities.' Contextual conditions affecting the phenomenon was 'Regret international marriage,' 'Experience conflicts,' and 'Look with negative prejudices,' 'Overcome the actual' and action/interaction strategies were 'Look for a breakthrough of life' and 'Manage to acceptance.' Intervening conditions for promoting or suppressing the action/interaction strategies for the central phenomenon were 'Social support system' and 'local limitations,' and as a result, the community living experiences of married immigrant women in rural areas appeared to 'Prepare the future,' 'Hope continuous social activities,' and 'Expect public support systems.'

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The Effect of Strategic Fit and Cooperative Relationships on the Small Suppliers' Performance (전략적 적합성 및 협력관계가 협력기업의 성과에 미치는 영향: 삼성전자 협력사를 대상으로)

  • Lee, Jangwoo;Kim, Minjae
    • The Journal of Small Business Innovation
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    • v.19 no.3
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    • pp.57-74
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    • 2016
  • This paper analyzes the role of strategic fit, cooperation, and performance in small-sized subpart suppliers' interactions with large businesses. For this purpose, this paper analyzes survey data from 90 first-tier suppliers of Samsung Electronics and evaluates how strategic fit and cooperative relationships affect their performance. Empirical analysis suggests that strategic fit positively affects small companies' business and innovation performance. This finding aligns with theories arguing for strategies that accommodate specific business environments. In addition, strategic fit is crucial for innovativeness of SMEs (Small and Medium-sized Enterprises). With regard to forming relationships with large companies, findings also show that high quality technological and personnel cooperation boosts subpart suppliers' productivity and efficiency as notably reflected in SMEs' business performance. Moreover, such cooperation between small and large companies reinforces the benefits associated with strategic fit and innovation. This means that if the business environment of small-sized subpart suppliers is uncertain, harnessing differentiated strategies and pursuing collaborations with prime companies will produce innovative outcomes (e.g., increased patent publications). On the other hand, when degree of uncertainty is small, pursuing cost leadership strategies and collaborating with prime companies in areas, such as technology and personnel, will help small-sized subpart suppliers produce innovative outcomes. Based on these findings, this paper argues that choosing the right competitive strategy for a specific business context is intrinsically tied to (1) augmenting technological and human collaborations with prime companies, (2) improving the quality of these interactions, and (3) generating competitiveness among small subpart suppliers. Both competition and cooperation are necessary for strengthening the competitiveness of small companies.

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A LSTM Based Method for Photovoltaic Power Prediction in Peak Times Without Future Meteorological Information (미래 기상정보를 사용하지 않는 LSTM 기반의 피크시간 태양광 발전량 예측 기법)

  • Lee, Donghun;Kim, Kwanho
    • The Journal of Society for e-Business Studies
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    • v.24 no.4
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    • pp.119-133
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    • 2019
  • Recently, the importance prediction of photovoltaic power (PV) is considered as an essential function for scheduling adjustments, deciding on storage size, and overall planning for stable operation of PV facility systems. In particular, since most of PV power is generated in peak time, PV power prediction in a peak time is required for the PV system operators that enable to maximize revenue and sustainable electricity quantity. Moreover, Prediction of the PV power output in peak time without meteorological information such as solar radiation, cloudiness, the temperature is considered a challenging problem because it has limitations that the PV power was predicted by using predicted uncertain meteorological information in a wide range of areas in previous studies. Therefore, this paper proposes the LSTM (Long-Short Term Memory) based the PV power prediction model only using the meteorological, seasonal, and the before the obtained PV power before peak time. In this paper, the experiment results based on the proposed model using the real-world data shows the superior performance, which showed a positive impact on improving the PV power in a peak time forecast performance targeted in this study.

A trend analysis of the cultivation status of medicinal crop farmers in Korea

  • Lee, Eun Song;An, Tae Jin;Park, Woo Tae;Jeong, Jin Tae;Lee, Yun Ji;Hur, Mok;Han, Jong Won;Han, Sin Hee;Kim, Young Guk;Park, Chun Geon;Chang, Jae Ki;Kim, Yong Il
    • Korean Journal of Agricultural Science
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    • v.47 no.1
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    • pp.139-161
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    • 2020
  • The aims of this study were to classify the cultivation status of medicinal crop farmers and to obtain basic data on domestic medicinal crops. To this end, 406 medicinal crop farmers participating in farming education programs in 14 cities and counties were surveyed over 10 months. The results were as follows. First, the biggest difficulty farmers faced in the overall production of medicinal crops was a lack of cultivation skills. Second, in a detailed inquiry about each difficulty item, the most difficult problems were injury by continuous cropping of root-using crops, shortage of specific farm machinery, uncertain market prices, and lack of knowledge about pest control or the positive list system (PLS). Third, the profitability of medicinal crops increased with career experience. Among the farmers who earned profits, requests for education and technical guidance were the most important factors for profitability. Fourth, the results of the analysis suggest that to achieve stable cultivation of medicinal crops, the following items need to be addressed: development and supply of basic cultivation technologies, climate response, registration of pest control pesticides, a solution to the injury by continuous cropping, and contracting cultivation expansion. Additionally, to improve profitability, it is necessary to create conditions that enable the same crops to grow for a long time in one region.

The Development of RFID Utility Statistical Analysis Tool (RUSAT) in Comparison to Barcode for Logistics Activities (물류활동에서 RFID와 바코드 시스템의 효용성 비교를 위한 통계분석 도구(RUSAT) 개발)

  • Ha, Heon-Cheol;Park, Heung-Sun;Kim, Hyun-Soo;Choi, Yong-Jung
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.5
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    • pp.137-146
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    • 2012
  • In SCM(Supply Chain Management), a management paradigm where the customer satisfaction is to be achieved by minimizing the cost, reducing the uncertainty, and obtaining the overall optimization. As it performs the integrated operation of the paths of information, assets, and knowledge from the raw material providers to the retailers, the adoption of RFID(Radio Frequency Identification) in SCM could be expected to magnify the effectiveness of the system. However, there is a huge risk by deciding whether or not RFID system is adopted without the objective analysis under the uncertain circumstances. This research paper presents the statistical analysis methodologies for the comparison of RFID with Barcode on the aspect of utility and the statistical analysis tool, RUSAT, which was programmed for nonstatisticians' convenience. Assuming a pharmaceutical industry, this paper illustrates how the data were entered and analyzed in RUSAT. The results of this research are expected to be used not only for the pharmaceutical related company but also for the manufacturer, the whole-saler, and the retailer in the other logistic industries.

New Statistical Pattern Recognition Technology for Condition Assessment of Cable-stayed Bridge on Earthquake Load (지진하중을 받는 사장교의 상태평가를 위한 새로운 통계적 패턴 인식 기술)

  • Heo, Gwanghee;Kim, Chunggil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.3
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    • pp.747-754
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    • 2014
  • In spite of its usefulness for health monitoring of structures on steady external load, the statistical pattern recognition technology (SPRT), based on Mahalanobis distance theory (MDT), is not good enough for the health monitoring of structures on large variability external load like earthquake. Damage is usually determined by the difference between the average measured value of undamaged structure and the measure value of damaged one. So when external variability gets larger, the difference gets bigger along, which is thus easily mistaken for a damage. This paper aims to overcome the problem and develop an improved Mahalanobis distance theory (IMDT), that is, a SPRT with revised MDT in order to decrease external variability so that we will be able to continue to monitor the structure on uncertain external variability. This method is experimentally tested to see if it precisely evaluates the health of a cable-stayed bridge on each general random load and earthquake load. As a result, the IMDT is found to be valid in locating structural damage made by damaged cables by means of data from undamaged cables. So it is proved to be effectively applicable to the health monitoring of bridges on external load of variability.