• Journal of Broadcast Engineering
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• v.28 no.3
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• pp.302-313
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• 2023

This paper aims to develop a framework that can fully automate the quality management of training data used in large-scale Artificial Intelligence (AI) models built by the Ministry of Science and ICT (MSIT) in the 'AI Hub Data Dam' project, which has invested more than 1 trillion won since 2017. Autonomous driving technology using AI has achieved excellent performance through many studies, but it requires a large amount of high-quality data to train the model. Moreover, it is still difficult for humans to directly inspect the processed data and prove it is valid, and a model trained with erroneous data can cause fatal problems in real life. This paper presents a dataset reconstruction framework that removes abnormal data from the constructed dataset and introduces strategies to improve the performance of AI models by reconstructing them into a reliable dataset to increase the efficiency of model training. The framework's validity was verified through an experiment on the autonomous driving dataset published through the AI Hub of the National Information Society Agency (NIA). As a result, it was confirmed that it could be rebuilt as a reliable dataset from which abnormal data has been removed.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.209-215
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• 2018

The level of cultural enjoyment in Korea has improved every year, but the culture that the general public possesses artworks has not developed so much. Most artwork trading systems, from traditional ones to the latest blockchain-based ones, are designed for expensive artwork trading and are hardly accessible to the general public. In this paper, we propose a blockchain-based artwork trading system that can improve the culture of the general public's art collection and contribute to the popularization of fine art. The proposed system consists of three interacted blockchains for identification, artwork registration and smart contract. The proposed system utilizes the advantages of the blockchain system for users to provide trust to each other, and introduces the concept of art notebook for artists to build trust in their own artwork. Since the proposed system builds a trust system through participants rather than experts or external organizations, it can reduce the cost of trading and deal with artworks that can be owned by the general public.

• Journal of Aerospace System Engineering
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• v.18 no.2
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• pp.12-20
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• 2024

The application of reinforcement design to ensure the structural safety of electronics in small satellites is limited by the spatial constraints of the satellite structure during launch vibrations. Additionally, a reliable evaluation approach is needed for mounting highly integrated devices that are susceptible to fatigue failure. Although the Steinberg fatigue failure theory has been used to assess the structural integrity of electronic devices, recent studies have highlighted its theoretical limitations. In this paper, we propose a structural methodology based on the critical strain theory to design the digital control unit (DCU) of the X-band SAR payload component for the small SAR technology experimental project (S-STEP), a small satellite constellation. To validate the design, we conducted modal and random analyses using simplified modeling techniques. Based on our methodology, we ultimately demonstrated the structural safety of the electronics through analysis results, safety margin derivation, and functional tests conducted both before and after the launch test.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.3
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• pp.18-25
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• 2005

Existing methods have performed the reliability analysis using nonlinear optimization techniques. This is mainly due to the fact that they directly apply Multidisciplinary Design Optimization(MDO) frameworks to the reliability analysis formulation. Accordingly, the reliability analysis and the Multidisciplinary Analysis(MDA) are tightly coupled in a single optimizer, which hampers utilizing the recursive and function-approximation based reliability analysis methods such as the Advanced First Order Reliability Method(AFORM). In order to utilize the efficient reliability analysis method under multidisciplinary analysis systems, we propose a new strategy named Sequential Approach on Reliability Analysis under Multidisciplinary analysis systems(SARAM). In this approach, the reliability analysis and the MDA are decomposed and arranged in a sequential manner, making a recursive loop. The efficiency of the SARAM method was verified using three illustrative examples taken from the literatures. Compared with existing methods, it showed the least number of subsystem analyses over other methods while maintaining accuracy.

• Journal of Korea Water Resources Association
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• v.42 no.6
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• pp.505-511
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• 2009

When replacing deteriorated pipes, it is important to select pipe diameters of new pipes for improving the long-term reliability of a water distribution system. However, as the use of larger diameter pipes brings cost increase, it is required to evaluate the improvement of the reliability by the use of larger diameter pipes. In this study, we propose a methodology to evaluate the improvement of the reliability by the use of different pipe diameters. For this purpose, we rely on the segment-based minimum cutset method with the success mode approach to evaluate the reliability of a water distribution system and determine which pipes and their diameters will be replaced to improve the reliability using GA, After the suggested method is applied to a real water distribution system, the optimized pipe diameters produces higher reliability of the system than the current ones with the same construction cost. However, compared to the increase rate of the construction cost, the improvement of the reliability is not significant. Thus, in addition to the use the different pipe diameters, the structural modification or adding new valves to the system is necessary to improve the reliability efficiently.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.23-30
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• 2017

In the AEC(Architecture, Engineering and Construction) industry, BIM(Building Information Modeling) technology not only helps design intent efficiently, but also realizes an object-oriented design including building's life cycle information. Thus it can manage all data created in each building stage and the roles of BIM are greatly expanded. Contractors and designers have been trying to adopt BIM to design competitions and validate it for the best result in various aspects. Via the computational simulation which differs from the existing process, effective evaluation can be done. For this process, a modeling guideline for each kind of BIM tool and a validation system for the confidential assessment are required. This paper explains a new process about design evaluation methods and process using BIM technologies which follow the new paradigm in construction industry through complement points by an example of a competition activity of the Korea Power Exchange(KPX) headquarter office. In conclusion, this paper provides a basic data input guideline based on open BIM for automatic assessment and interoperability between different BIM systems and suggests a practical usage of the rule-based Model Checker.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.7
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• pp.805-811
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• 2012

The reliability based design optimization (RBDO) approach requires high computing cost to consider uncertainties. In order to reduce the design cost, the single loop single vector (SLSV) approach has been developed for RBDO. This method can reduce the cost in calculating deign sensitivity by elimination of the nested optimization process. However, this process causes the increment of the instability or inaccuracy of the method according to the problem characteristics. Therefore, the method may not give accurate solution or the robustness of the solution is not guaranteed. Especially, when the function is concave, the process frequently diverges. In this research, the concept of the conjugate gradient method for unconstrained optimization is utilized to develop a new single loop single vector method. The conjugate gradient is calculated with gradient directions at the most probable points (MPP) of previous cycles. Mathematical examples are solved for the verification of the proposed method. The numeri cal performances of the obtained results are compared to those of other RBDO methods. The SLSV approach using conjugate gradient is not greatly influenced by the problem characteristics and improves its convergence capability.

• Review of KIISC
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• v.13 no.6
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• pp.55-66
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• 2003

본고에서는 개발자에게 단위, 통합 및 서비스 시험에 대한 시험과정 보증문서 작성 기법에 대한 참고자료를 제공하기 위하여, 국내에서 개발된 침입차단시스템과 침입탐지시스템 평가기준에 의한 시험과정 보증요구사항을 분석하여 소프트웨어 공학에 기반한 전통적인 구조적 방법론을 토대로 한 시험과정 보증문서 작성 경험을 기술하고자 한다. 따라서, 개발자는 사용자 요구사항에 의한 객관적이고 체계적인 시험과정을 이해하여 시스템 개발에서 발생할 수 있는 오류를 줄일 수 있으며 또한, 정확한 보안 기능명세 및 시험보증 설계$.$개발$.$구현을 통하여 제품의 안전성 및 신뢰성 향상에 기여할 것으로 기대된다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.346-348
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• 2004

최근 개발되는 임베디드 시스템의 경우 하드웨어와 소프트웨어의 구조가 매우 복잡해짐에 따라, 시스템에 탑재되는 소프트웨어의 신뢰성 확보를 위한 테스트 절차가 요구되고 있다. 특히 시스템에 탑재되는 소프트웨어는 다중 함수에 의해 의사결정이 되면서. 시스템 디자인 단계에서 요구되는 스펙(Specification)을 만족하지 못하는 경우가 빈번하게 발생한다 본 논문에서는 임베디드 소프트웨어의 자동화된 테스트를 위해 요구되는 검증 모듈을 디자인하고 구현하였다 검증 모듈은 요구사항 기반으로 설계되었으며, 각각의 요구사항을 만족하는 검증 모듈을 구현하여 실제 상용화 제품에 대한 테스트를 진행하였다.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11a
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• pp.466-469
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• 2003

PC의 컴퓨팅 능력과 네트워크 성능이 급속도로 향상됨에 따라 이러한 인프라를 바탕으로 떠오르고 있는 Peer-to-Peer (P2P) 시스템은 자원의 복제 및 공유를 통하여 컴퓨팅 시스템 전반에 걸친 신뢰성과 결함감내 능력을 향상시킨다. 그러나 현재까지 연구된 P2P 네트워크는 각 노드가 복제한 데이터의 일관성 유지를 위해 필요한 그룹통신에 대한 고려가 부족하다. 본 논문은 SpanningTree 방식의 링 구성을 통하여, P2P 시스템에서의 그룹통신을 위해 설계된 메시지 전송 방식을 설명하고 기존 P2P 메시지 전송방식과의 비교를 통하여 성능향상의 근거를 보인다.