• 제목/요약/키워드: Two stage approach

검색결과 554건 처리시간 0.024초

A Study on the Determinants of Decommissioing Cost for Nuclear Power Plant (NPP)

  • Cha, Hyungi;Yoon, Yongbeum;Park, Soojin
    • 방사성폐기물학회지
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    • 제19권1호
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    • pp.87-111
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    • 2021
  • Nuclear power plants (NPPs) produce radioactive waste and decommissioning this waste entails additional cost; determining these costs for various types and specifications of radioactive waste can be challenging. The purpose of this study is to identify major determinants of the decommissioning cost and their impact on NPPs. To this end, data from defunct NPPs were gathered and 2SLS (Two Stage Least Squares) regression models were developed to investigate the major contributors depending on the reactor types, viz. PWR (Pressurized Water Reactors) and BWR (Boiling Water Reactors). Additionally, cost estimations and the Monte Carlo simulation were performed as part of performance validation. Our study established that the decommissioning costs are primarily influenced by the level of radioactivity in the decommissioned waste, which can be realized from operational factors like operation period, overall efficiency, and plant capacity, as well as from duration of decommissioning and labour cost. While our study provides an improved statistical approach to recognize these factors, we acknowledge that our models have limitations in forecasting accurately which we envisage to bolster in future studies by identifying more substantive factors.

An End-to-End Sequence Learning Approach for Text Extraction and Recognition from Scene Image

  • Lalitha, G.;Lavanya, B.
    • International Journal of Computer Science & Network Security
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    • 제22권7호
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    • pp.220-228
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    • 2022
  • Image always carry useful information, detecting a text from scene images is imperative. The proposed work's purpose is to recognize scene text image, example boarding image kept on highways. Scene text detection on highways boarding's plays a vital role in road safety measures. At initial stage applying preprocessing techniques to the image is to sharpen and improve the features exist in the image. Likely, morphological operator were applied on images to remove the close gaps exists between objects. Here we proposed a two phase algorithm for extracting and recognizing text from scene images. In phase I text from scenery image is extracted by applying various image preprocessing techniques like blurring, erosion, tophat followed by applying thresholding, morphological gradient and by fixing kernel sizes, then canny edge detector is applied to detect the text contained in the scene images. In phase II text from scenery image recognized using MSER (Maximally Stable Extremal Region) and OCR; Proposed work aimed to detect the text contained in the scenery images from popular dataset repositories SVT, ICDAR 2003, MSRA-TD 500; these images were captured at various illumination and angles. Proposed algorithm produces higher accuracy in minimal execution time compared with state-of-the-art methodologies.

Mesh Stability Study for the Performance Assessment of a Deep Geological Repository Using APro

  • Hyun Ho Cho;Hong Jang;Dong Hyuk Lee;Jung-Woo Kim
    • 방사성폐기물학회지
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    • 제21권2호
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    • pp.283-294
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    • 2023
  • APro, developed in KAERI for the process-based total system performance assessment (TSPA) of deep geological disposal systems, performs finite element method (FEM)-based multiphysics analysis. In the FEM-based analysis, the mesh element quality influences the numerical solution accuracy, memory requirement, and computation time. Therefore, an appropriate mesh structure should be constructed before the mesh stability analysis to achieve an accurate and efficient process-based TSPA. A generic reference case of DECOVALEX-2023 Task F, which has been proposed for simulating stationary groundwater flow and time-dependent conservative transport of two tracers, was used in this study for mesh stability analysis. The relative differences in tracer concentration varying mesh structures were determined by comparing with the results for the finest mesh structure. For calculation efficiency, the memory requirements and computation time were compared. Based on the mesh stability analysis, an approach based on adaptive mesh refinement was developed to resolve the error in the early stage of the simulation time-period. It was observed that the relative difference in the tracer concentration significantly decreased with high calculation efficiency.

모바일 앱 및 키오스크 사용자의 추천의도에 관한 연구 ; 비대면서비스 이미지의 매개효과를 중심으로 (Investigating the Recommendation Intention of Customers on the Mobile App and KIOSK: Focused on the Mediating Effect of Untact Service Image)

  • 박종순;김창식
    • 디지털산업정보학회논문지
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    • 제19권2호
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    • pp.177-186
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    • 2023
  • This study investigates customers' perceptions of untack services in the hospitality and foodservice industries based on the Technology Acceptance Model (TAM). The study first identifies Perceived Ease of Use, Perceived Usefulness, and Image as antecedents of customers' Behavioral Intention and Recommendation Intention. Second, the structural relationships among them are established and tested. The study adopts a self-administered survey method, uses SmartPLS 4.0, and applies a two-stage approach. After testing the reliability and validity of customers' 429 data on hospitality and foodservice, hypotheses were tested. The results showed that Perceived Ease of Use significantly affects Perceived Usefulness and Image. Perceived Usefulness significantly also affects Image and Behavioral Intention. The Image of untact services also significantly affects Behavioral Intention and Recommendation Intention. And Behavioral Intention significantly affects Recommendation Intention. Finally, the mediation effects are also all significant. The study's findings suggest that researchers and practitioners should consider the management of Image and Recommendation Intention in the untact service environment.

How to quantify the similarity of 2D distributions: Comparison of spatial distribution of Dark Matter and Intracluster light

  • Yoo, Jaewon;Ko, Jongwan;Sabiu, Cristiano G.;Chun, Kyungwon;Shin, Jihye;Hwang, Ho Seong;Smith, Rory;Kim, Hyowon
    • 천문학회보
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    • 제46권2호
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    • pp.67.4-68
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    • 2021
  • In studying the dynamical evolution of galaxy clusters, one intriguing approach is to compare the spatial distributions of various components, such as the dark matter, the member galaxies, the gas, and the intracluster light (ICL; the diffuse light from stars, which are not bound any individual cluster galaxy). If we find a visible component whose spatial distribution coincides with the dark matter distribution, then we could draw a dark matter map without requiring laborious weak lensing analysis. Furthermore, if the component traces the dark matter distribution better for more relaxed galaxy cluster, we could use the similarity as a dynamical stage estimator of the galaxy cluster. We present a novel new methodology to quantify the similarity of two or more 2-dimensional spatial distributions. We apply the method to a sample of galaxy clusters at different dynamical stages simulated within N-cluster Run, which is an N-body simulation using the galaxy replacement technique. Among the various components (stellar particles, galaxies, ICL), the velocity defined ICL+ brightest cluster galaxy (BCG) component traces the dark matter best. Between the sample galaxy clusters, the relaxed clusters show stronger similarity of the spatial distribution between the dark matter and ICL+BCG than the dynamically young clusters.

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Retrospective Analysis of Neoadjuvant Chemotherapy for Breast Cancer in Turkish Patients

  • Duman, Berna Bozkurt;Afsar, Cigdem Usul;Gunaldi, Meral;Sahin, Berksoy;Kara, I. Oguz;Erkisi, Melek;Ercolak, Vehbi
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권8호
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    • pp.4119-4123
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    • 2012
  • Background: Neoadjuvant systemic chemotherapy is the accepted approach for women with locally advanced breast cancer. Anthracycline- and taxane-based regimens have been extensively studied in clinical trials and consequently are widely used. In this study aimed to research the complete response (pCR) rates in different regimens for neoadjuvant setting and determine associated clinical and biological factors. Methods: This study included 63 patients diagnosed with breast carcinoma among 95 patients that had been treated with neoadjuvant chemotherapy between 2007 and 2010. TNM staging system was used for staging. The histologic response to neoadjuvant chemotherapy was characterized as a pCR when there was no evidence of residual invasive tumor in the breast or axillary lymph nodes. Biologic subclassification using estrogen receptor (ER), progesterone receptor (PR), HER2 were performed. Luminal A was defined as ER+, PR+, HER2-; Luminal B tumor was defined as ER+, PR-, HER2-; ER+, PR-, HER2+; ER-, PR+, HER2-; ER+, PR+, HER2+; HER2 like tumor ER-, PR+, HER2+; and triple negative tumor ER, PR, HER2 negative. Results: Patients median age was 54.14 (min-max: 30-75). Thirty-two patients (50.8%) were premenapousal and 31 (49.2%) were postmenapousal. Staging was performed postoperatively based on the pathology report and appropriated imaging modalities The TNM (tumor, lymph node, metastasis) system was used for clinical and pathological staging. Fifty-seven (90.5%) were invasive ductal carcinomas, 6 (9.5%) were other subtypes. Thirty nine (61.9%) were grade II and 24 (38.1%) were grade III. Seven (11.1%) patients were stage II and 56 (88.9) patients were stage III. The patients were classified for ER, PR receptor and HER2 positivity. Seventeen patients had complete response to chemotherapy. Forty patients (63.5%) were treated with dose dense regimen (cyclophosphamide 600 mg/m2 and doxorubicine 60 mg/m every two weeks than paclitaxel 175 mg/m2 every two weeks with filgrastim support) 40 patients (48%) were treated anthracycline and taxane containing regimens. Thirteen patients (76%) from 17 patients with pCR were treated with the dose dense regimen but without statistical significance (p=0.06). pCR was higher in HER2(-), ER(-), grade III, premenopausal patients. Conclusion: pCR rate was higher in the group that treated with dose dense regimen, which should thus be the selected regimen in neoadjuvant setting. Some other factors can predict pCR in Turkish patients, like grade, menopausal status, triple negativity, percentage of ER positivity, and HER2 expression.

SP 순위 자료별 오차를 고려하는 순위로짓 모형 추정에 관한 연구 (Development of Scaled Explosion Logit Model Considering Reliability of Ranking Data)

  • 김강수;조혜진
    • 대한교통학회지
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    • 제22권6호
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    • pp.197-206
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    • 2004
  • SP 순위자료는 모든 선택 가능한 대안을 일괄적으로 제시하고 응답자에게 대안을 선호 순서대로 평가하게 하는 방법으로, 표현되는 순위는 선택대안 효용의 크기 순서를 의미한다. 그러나 순위자료는 선택대안이 많은 경우 응답자가 제시하는 순위가 낮을수록, 혹은 하위 순위부터 응답자가 적는 경우는 고려하는 경우 순위가 높을수록 순위자료의 신뢰성은 떨어진다. 본 논문의 목적은 SP 순위자료를 이용하여 SP 순위모형을 추정하는 방법론에 대해서 살표보고 각 순위별 자료가 갖고 있는 신뢰성을 분석하고 이를 극복하는 방법론을 제시하는데 있다. 이를 위해 화물운송수단 SP 순위자료를 활용하여 기존 순위확장(exploded logit) 모형이 내재하는 가정, 즉 각 순위별 자료의 오차는 동일하고 독립적인 선택자료로 변환할 수 있다는 가정을 검증하고 순위가 내려갈수록, 혹은 올라갈수록 각 순위자료가 갖는 오차의 정도를 반영하여 이를 극복할 수 있는 방법론을 제시한다. 또한, 순위자료를 단순 선택자료로 확장시키는 경우 몇순위까지 확장시키는 것이 타당한가를 실증적으로 제시한다. 분석결과, SP 순위자료에서는 순위가 낮아지면서 상이한 오차 및 의사결정 행태가 존재해 순위자료를 독립적인 선택자료로 단순 확장하여 순위로짓보형으로 단순 추정하면 편의가 발생할 수 있음을 보여주었다. 또한 본 연구의 사례 분석 결과 2순위까지만 단순 독립적인 선택 자료로 확장이 가능하며, 2순위를 초과하면서 선호자료를 독립적인 선택자료로 단순 확장하는 것은 순위자료를 추정하는 데 있어 편의를 발생시키는 것으로 나타났다. 본 연구의 결과는 특정 사례에 대해서 분석된 결과이지만 적용된 방법론은 일반적인 방법론으로써 SP 순위자료의 신뢰성을 제고시키는 분석 방법론에 대한 일조할 것으로 기대한다.

정태 안전성 평가를 고려한 무효전력 전압제어를 위한 A-team기반 접근법 (A-team Based Approach for Reactive Power/Voltage Control Considering Steady State Security Assessment)

  • Kim, Doo-Hyun
    • 한국안전학회지
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    • 제11권2호
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    • pp.150-159
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    • 1996
  • 본 연구에서는 하부구조적 결함을 갖는 전력계통의 정태 안전성 평가를 고려한 무효전력 제어 문제를 해결하기 위하여 A-team(Asynchronous team) 이론을 이용한 접근법을 제시한다. QVC는 무효전력 발전량, 전압치, 선로조류 및 다른 무효전력장치에 대한 제약조건하에서 최적의 전압을 유지하는 문제로써, 해의 정확도를 크게 해치지 않는 범위내에서 혼합정수계획법(MILP) 문제로 수식화 하였다. 안전성 평가는 계통의 모니터링을 통하여 얻어진 현재의 자료를 평가하여 상대적 강인성을 추정하는 것으로 교류 전력조류법에 기반을 둔 결정론적인 방법에 의해 계통안전성, 특히 전압안전성을 평가하였으며, 이진치 대신에 다수의 이산치를 제공하는 안전성 계량을 사용하였다. 계통의 효율적 운전을 목적으로 위의 두 문제를 통합하여 풀 수 있도록 A-team으로 명명된 새로운 조직기법을 도입하였다. A-team은 자치적(autonomous)이고, 병렬적으로(in parallel) 동작하고, 비동기적으로(asynchronously) 정보교환을 하는 agent들을 위 한 일종의 조직법으로 다수의 프로그램 (computer-based multi agent)을 이 용한 운용시스템의 구성에 적합한 방법으로 알려져 있다. 이 A-team을 이용한 방법은 실계통에 적용하기 위한 초기단계에 머무르고 있으나 대형계통의 여러 복잡한 문제를 해결할 수 있는 가능성을 갖고 있다.

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정교화 가능성 모형에 의한 IT 피교육자 신용 믿음 변화의 종단분석 (An Longitudinal Analysis of Changing Beliefs on the Use in IT Educatee by Elaboration Likelihood Model)

  • 이웅규
    • Asia pacific journal of information systems
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    • 제18권3호
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    • pp.147-165
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    • 2008
  • IT education can be summarized as persuading the educatee to accept IT. The persuasion is made by delivering the messages for how-to-use and where-to-use to the educatee, which leads formulation of a belief structure for using IT. Therefore, message based persuasion theory, as well as IT acceptance theories such as technology acceptance model(TAM), would play a very important role for explaining IT education. According to elaboration likelihood model(ELM) that has been considered as one of the most influential persuasion theories, people change attitude or perception by two routes, central route and peripheral route. In central route, people would think critically about issue-related arguments in an informational message. In peripheral route, subjects rely on cues regarding the target behavior with less cognitive efforts. Moreover, such persuasion process is not a one-shot program but continuous repetition with feedbacks, which leads to changing a belief structure for using IT. An educatee would get more knowledge and experiences of using IT as following an education program, and be more dependent on a central route than a peripheral route. Such change would reformulate a belief structure which is different from the intial one. The objectives of this study are the following two: First, an identification of the relationship between ELM and belief structures for using IT. Especially, we analyze the effects of message interpretation through both of central and peripheral routes on perceived usefulness which is an important explaining variable in TAM and perceived use control which have perceived ease of use and perceived controllability as sub-dimensions. Second, a longitudinal analysis of the above effects. In other words, change of the relationship between interpretation of message delivered by IT education and beliefs of IT using is analyzed longitudinally. For achievement of our objectives, we suggest a research model, which is constructed as three-layered. While first layer has a dependent variable, use intention, second one has perceived usefulness and perceived use control that has two sub-concepts, perceived ease of use and perceived controllability. Finally, third one is related with two routes in ELM, source credibility and argument quality which are operationalization of peripheral route and central route respectively. By these variables, we suggest five hypotheses. In addition to relationship among variables, we suggest two additional hypotheses, moderation effects of time in the relationships between perceived usefulness and two routes. That is, source credibility's influence on perceived usefulness is decreased as time flows, and argument quality's influence is increased. For validation of it, our research model is tested empirically. With measurements which have been validated in the other studies, we survey students in an Excel class two times for longitudinal analysis. Data Analysis is done by partial least square(PLS), which is known as an appropriate approach for multi-group comparison analysis with a small sized sample as like this study. In result. all hypotheses are statistically supported. One of theoretical contributions in this study is an analysis of IT education based on ELM and TAM which are considered as important theories in psychology and IS theories respectively. A longitudinal analysis by comparison between two surveys based on PLS is also considered as a methodological contribution. In practice, finding the importance of peripheral route in early stage of IT education should be notable.

BUILDING INFORMATION MODELING (BIM)-BASED DESIGN OF ENERGY EFFICIENT BUILDINGS

  • Cho, Chung-Suk;Chen, Don;Woo, Sungkwon
    • 한국BIM학회 논문집
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    • 제2권1호
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    • pp.1-6
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    • 2012
  • With the increased awareness of energy consumption as well as the environmental impact of building operations, architects, designers and planners are required to place more consideration on sustainability and energy performance of the building. To ensure most of those considerations are reflected in the building performance, critical design decisions should be made by key stakeholders early during the design development stage. The application of BIM during building energy simulations has profoundly improved the energy analysis process and thus this approach has gained momentum. However, despite rapid advances in BIM-based processes, the question still remains how ordinary building stakeholders can perform energy performance analysis, which has previously been conducted predominantly by professionals, to maximize energy efficient building performance. To address this issue, we identified two leading building performance analysis software programs, Energy Plus and IES (IES ), and compared their effectiveness and suitability as BIM-based energy simulation tools. To facilitate this study, we examined a case study on Building Performance Model (BPM) of a single story building with one door, multiple windows on each wall, a slab and a roof. We focused particularly on building energy performance by differing building orientation and window sizes and compared how effectively these two software programs analyzed the performance. We also looked at typical decision-making processes implementing building energy simulation program during the early design stages in the U.S. Finally, conclusions were drawn as to how to conduct BIM-based building energy performance evaluations more efficiently. Suggestions for further avenues of research are also made.