• 한국압력기기공학회 논문집
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• 제19권2호
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• pp.93-101
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• 2023

In this study, a deep learning algorithm was used to diagnose electric potential signals obtained through CIPS and DCVG, used indirect inspection methods to confirm the soundness of buried pipes. The deep learning algorithm consisted of CNN(Convolutional Neural Network) model for diagnosing the electric potential signal and Grad CAM(Gradient-weighted Class Activation Mapping) for showing the flaw prediction point. The CNN model for diagnosing electric potential signals classifies input data as normal/abnormal according to the presence or absence of flaw in the buried pipe, and for abnormal data, Grad CAM generates a heat map that visualizes the flaw prediction part of the buried pipe. The CIPS/DCVG signal and piping layout obtained from the 3D finite element model were used as input data for learning the CNN. The trained CNN classified the normal/abnormal data with 93% accuracy, and the Grad-CAM predicted flaws point with an average error of 2m. As a result, it confirmed that the electric potential signal of buried pipe can be diagnosed using a CNN-based deep learning algorithm.

• Imaging Science in Dentistry
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• 제50권3호
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• pp.183-192
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• 2020

Purpose: This study was performed to assess the accuracy of preoperative cone-beam computed tomography (CBCT), when justified for other reasons, in locating the apical foramen and establishing the working length. Materials and Methods: Six electronic databases were searched for studies on this subject. All studies, of any type, were included if they compared measurements of working length with preoperative CBCT to measurements using an electronic apex locator (EAL) or histological reference standard. Due to the high levels of heterogeneity, an inverse-variance random-effects model was chosen, and weighted mean differences were obtained with 95% confidence intervals and P values. Results: Nine studies were included. Compared to a histological reference standard, CBCT indicated that the apical foramen was on average 0.40 mm coronal of its histological position, with a mean absolute difference of 0.48 mm. Comparisons were also performed to an EAL reference standard, but the conclusions could not be considered robust due to high levels of heterogeneity in the results. Conclusion: A low level of evidence is produced suggesting that preoperative CBCT shows the apical foramen to be on average 0.40 mm coronal to its histological position, with a mean absolute difference of 0.48 mm.

• Nuclear Engineering and Technology
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• 제22권4호
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• pp.410-415
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• 1990

MN(Madland-Nix) 모형에 바탕을 둔 핵분열 즉발 중성자 에너지 스펙트럼을 핵분열 유기중성자의 에너지 함수로서 구했다. 이 중성자 스펙트럼을 $^{27}$ Al(n,$\alpha$), $^{32}$S(n,p) 및 $^{115}$ In(n,n') 발단 방사화 검출기의 여기함수에 증율시켜 평균핵반응 단면적을 계산하고 상호간의 비, 즉, 중성자 스펙트럼 지수를 구했다. 그 결과 핵분열 유기중성자의 에너지에 따라 중성자 스펙트럼은 변하며 그에 따라 중성자 스펙트럼 지수도 변함을 보였다. 이것은 곧 중성자 스펙트럼 지수를 실험적으로 결정하므로써 핵분열 즉발 중성자 에너지 스펙트럼을 결정할 수 있음을 의미한다.

• Industrial Engineering and Management Systems
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• 제4권1호
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• pp.23-35
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• 2005

This paper aims to develop a practical finite capacity MRP (FCMRP) system based on the needs of an automotive parts manufacturing company in Thailand. The approach includes a linear goal programming model to determine the optimal start time of each operation to minimize the sum of penalty points incurred by exceeding the goals of total earliness, total tardiness, and average flow-time considering the finite capacity of all work centers and precedence of operations. Important factors of the proposed FCMRP system are penalty weights and dispatching rules. Effects of these factors on the performance measures are statistically analyzed based on a real situation of an auto-part factory. Statistical results show that the dispatching rules and penalty weights have significant effects on the performance measures. The proposed FCMRP system offers a good tradeoff between conflicting performance measures and results in the best weighted average performance measures when compared to conventional forward and forward-backward finite capacity scheduling systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권1호
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• pp.64-88
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• 2024

Security and reliability are the utmost importance facts in intelligent networked vehicles. Stochastic Petri Net and Z (SPZN) as an excellent formal verification tool for modeling concurrent systems, can effectively handles concurrent operations within a system, establishes relationships among components, and conducts verification and reasoning to ensure the system's safety and reliability in practical applications. However, the application of a system with numerous nodes to Petri Net often leads to the issue of state explosion. To tackle these challenges, a refinement and abstraction method based on SPZN is proposed in this paper. This approach can not only refine and abstract the Stochastic Petri Net but also establish a corresponding relationship with the Z language. In determining the implementation rate of transitions in Stochastic Petri Net, we employ the interval average and weighted average method, which significantly reduces the time and space complexity compared to alternative techniques and is suitable for expert systems at various levels. This reduction facilitates subsequent comprehensive system analysis and module analysis. Furthermore, by analyzing the properties of Markov Chain isomorphism in the case study, recommendations for minimizing system risks in the application of intelligent parking within the intelligent networked vehicle system can be put forward.

• 한국광학회지
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• 제11권6호
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• pp.395-399
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• 2000

백색광 간섭계에서는 신속하고 그리고 정확하게 주사방향의 간섭무늬 봉우리점을 추출하는 것이 중요한 관건이다. 봉우리점 산출 속도 향상을 목표로 하여 많은 연구가 진행되어 왔지만, 본 연구에서는 가장 간단한 셈법을 이용하여 기준 시료가 얼마나 정확하게 재구성 되는가를 비교 검토하였다. 두 방법 모두 nm 수준의 정밀도로 단차를 측정할 수 있었는데 역상관을 이용한 셈법이 표면 구조나 수직한 면의 재구성에 더 충실한 결과를 산출함이 관찰되었다.

• 물과 미래
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• 제28권1호
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• pp.133-144
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• 1995

본 연구의 목적은 실시간 자료수집 시스템의 일환으로서 어떤 유역에 존재하는 기존의 강우관측지점으로로부터 유역평균강우량을 산정할 때나 이를 강우-유출 모형의 입력치로 사용할 때 필요한 강우관측지점의 수와 위치를 선정하는 방법을 제시하였다. 유역평균강우량 산정방법은 미국 국립기상청이 제안한 가중치방법을 사용하였다. 강우관측지점 수에 따른 국부적인 최적위치선정은 서로 다른 두가지 방법으로 추적되었다. 유량예측을 위한 강우관측지점의 최적위치와 수를 결정하기 위하여 실제 실무에서 적용하고 있는 강우-유출 모형을 사용하였다.

• 인터넷정보학회논문지
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• 제1권2호
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• pp.89-96
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• 2000

영상의 유사성에 대한 사용자의 주관적인지를 학습하는 방법으로 relevance feedback 기술이 사용되며, 최근 들어 이에 대한 관심이 높아지고 있다. 대부분의 relevance feedback기술은 영상 유사성을 측정하는데 사용되는 특징이 서로 독립적이라는 가정하고 있으나, 이러한 가정은 유사성 판단을 모델링 하는데 있어서 상당한 제약을 두는 것이다. 이 논문에서는. 퍼지 측정과 Choquet 적분을 이용하여, 유사성 판단에 대한 보다 나은 모델링 방법을 제안하고, 이를 이용한 relevance feedback 알고리즘을 제안한다. 실험결과를 통하여, 기존의 가중치 평균 방식에 의한 relevance feedback보다 제안된 방식이 우수함을 보인다.

• 한국군사과학기술학회지
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• 제13권5호
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• pp.808-817
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• 2010

This paper proposes a novel appoach which can assess the system technical maturity for use in Defense R&D Program reviews. As the weapon systems become more complicated, the success and effectiveness of R&D outcome heavily depend on the application and tailoring of systems engineering process and methods. It is a difficult task to assess the system readiness level(SRL) of the system being developed. A system-focused approach for managing weapon systems development and making effective and efficient decisions during the development lifecycle is critical to ensure the success of the program. The proposed weighted average SRL can facilitate the system technical maturity assessment without expending heavy work load.

• Journal of Information Processing Systems
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• 제18권4호
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• pp.500-509
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• 2022

With the rapid development of educational informatization, teaching methods become diversified characteristics, but a large number of information data restrict the evaluation on teaching subject and object in terms of the effect of English education. Therefore, this study adopts the concept of incremental learning and eigenvalue interval algorithm to improve the weighted decision tree, and builds an English education effect evaluation model based on association rules. According to the results, the average accuracy of information classification of the improved decision tree algorithm is 96.18%, the classification error rate can be as low as 0.02%, and the anti-fitting performance is good. The classification error rate between the improved decision tree algorithm and the original decision tree does not exceed 1%. The proposed educational evaluation method can effectively provide early warning of academic situation analysis, and improve the teachers' professional skills in an accelerated manner and perfect the education system.