• Title/Summary/Keyword: 결함 관리 기법

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Numerical Modeling for the Identification of Fouling Layer in Track Ballast Ground (자갈도상 지반에서의 파울링층 식별을 위한 수치해석연구)

  • Go, Gyu-Hyun;Lee, Sung-Jin
    • Journal of the Korean Geotechnical Society
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    • v.37 no.9
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    • pp.13-24
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    • 2021
  • Recently, attempts have been made to detect fouling patterns in the ground using Ground Penetrating Radar (GPR) during the maintenance of gravel ballast railway tracks. However, dealing with GPR signal data obtained with a large amount of noise in a site where complex ground conditions are mixed, often depends on the experience of experts, and there are many difficulties in precise analysis. Therefore, in this study, a numerical modeling technique that can quantitatively simulate the GPR signal characteristics according to the degree of fouling of the gravel ballast material was proposed using python-based open-source code gprMax and RSA (Random sequential Absorption) algorithm. To confirm the accuracy of the simulation model, model tests were manufactured and the results were compared to each other. In addition, the identification of the fouling layer in the model test and analysis by various test conditions was evaluated and the results were analyzed.

A Study on How to Extend The Inspection Period for The One-Shot System (One-Shot System에 대한 점검주기 연장 방안 연구)

  • Kim, Jong-jin;Song, Jeong-hun;Han, Jung-won;Lee, Chang-kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.113-118
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    • 2021
  • The guided weapon system should ensure economical operation and user safety. In particular, in the case of guided weapon systems developed in the form of a guaranteed bomb, the standards for maintaining reliability considering the long-term storage environment are presented during the development stage, and an optimized inspection cycle is required to maintain this. This study calculated the reliability through a trend test, fitness test, and distribution analysis using a mathematical model based on the maintenance status and shooting results during the inspection period for OO missiles currently in operation for a long time in the military. Through this, it was applied to the inspection period model (Martinez) set during the development stage to determine if the improved inspection period can be utilized. Finally, by synthesizing the data from these studies, a policy management plan was developed according to the extension of the inspection period. The One-Shot system was operated at the inspection period set when it was developed. The study analyzed the actual failure and maintenance data to reset the efficient inspection period.

A Study on the Analysis of Positional Accuracy between the GPR Survey Data and Underground Space Integration Map (현장 GPR 탐사자료와 지하공간통합지도 상호위치 정확도 분석에 관한 연구)

  • SONG, Seok-Jin;CHO, Hae-Yong;HAN, Dam-Hye;KIM, Sung-Gil
    • Journal of the Korean Association of Geographic Information Studies
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    • v.23 no.4
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    • pp.208-216
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    • 2020
  • Recently, issues regarding underground safety such as sink hole, ground subsidence and damage to old underground facilities have been increasing in urban areas, raising the need for more accurate management of underground facilities. Thus, this study derived a technique for comparing spatial data of underground facilities acquired from GPR exploration results acquired at the site with spatial data of integrated underground spatial maps. Using this underground space integrated map-linked service prototype program developed through this study, comparing the location information of the GPR exploration results and the underground space integrated map for the verification of site usability in some sections around Gangnam Station, the results demonstrated that the location of the map is 0.879m maximum, minimum of 0.101m and the average fudge factor was 0.625m. If accuracy of the GPR exploration results is guaranteed, it is judged that it can be used to improve the location accuracy of the underground space integration map.

An Aggregate Detection of Event Correlation using Fuzzy Control (퍼지제어를 이용한 관련성 통합탐지)

  • 김용민
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.13 no.3
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    • pp.135-144
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    • 2003
  • An intrusion detection system shows different result over overall detection area according to its detection characteristics of inner detection algorithms or techniques. To expand detection areas, we requires an integrated detection which can be archived both by deploying a few detection systems which detect different detection areas and by combining their results. In addition to expand detection areas, we need to decrease the workload of security managers by false alarms and improve the correctness by minimizing false alerts which happen during the process of integration. In this paper, a method for aggregation detection use fuzzy inference to integrate a vague detection results which imply the characteristics of detection systems. Their analyzed detection characteristics are expressed as fuzzy membership functions and fuzzy rule bases which are applied through the process of fuzzy control. And, it integrate a vague decision results and minimize the number of false alerts by reflecting the characteristics of detection systems. Also it does minimize inference objects by applying thresholds decided through several experiments.

Automated Attack Path Enumeration Method based on System Vulnerabilities Analysis (시스템 취약점 분석을 통한 침투 경로 예측 자동화 기법)

  • Kim, Ji Hong;Kim, Huy Kang
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.22 no.5
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    • pp.1079-1090
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    • 2012
  • As the number of information asset and their vulnerabilities are increasing, it becomes more difficult for network security administrators to assess security vulnerability of their system and network. There are several researches for vulnerability analysis based on quantitative approach. However, most of them are based on experts' subjective evaluation or they require a lot of manual input for deriving quantitative assessment results. In this paper, we propose HRMS(Hacking and Response Measurement System) for enumerating attack path using automated vulnerability measurement automatically. HRMS can estimate exploitability of systems or applications based on their known vulnerability assessment metric, and enumerate attack path even though system, network and application's information are not fully given for vulnerability assessment. With this proposed method, system administrators can do proactive security vulnerability assessment.

A Case Study on the Effect of the Extracurricular Program of Convergence Major in Lifelong Education of Persons with Disabilities in Universities on Restaurant Employment Skills of High School Students with Intellectual and Developmental Disabilities (대학 학과 간 장애인평생교육 융합전공 탐색 비교과프로그램이 지적 및 발달장애 고등학생의 식당취업기술에 미치는 효과)

  • Kim, Young-Jun;Kwon, Ryang-Hee
    • Journal of Convergence for Information Technology
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    • v.11 no.7
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    • pp.136-144
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    • 2021
  • This study was conducted to verify the effectiveness of the university's extracurricular program of convergence majors on lifelong education for the disabled on the performance of restaurant employment skills for high school students with intellectual and developmental disabilities. The research method consisted of a case study procedure for three intellectual and developmental disability high school students, specifically using a single subject research technique. The study found that high school students with intellectual and developmental disabilities effectively acquired and maintained restaurant employment skills through extracurricular program on convergence majors of lifelong education for the disabled. In conclusion, the university's extracurricular program on convergence major of lifelong education for the disabled was analyzed to be effective in adapting to adult life and self-reliance, including restaurant employment skills of students with intellectual and developmental disabilities.

Fuzzy FMEA for Rotorcraft Landing System (회전익 항공기 착륙장치에 대한 퍼지 FMEA)

  • Na, Seong-Hyeon;Lee, Gwang-Eun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.1
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    • pp.751-758
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    • 2021
  • Munitions must be analyzed to identify any risks for quality assurance in development and mass production. Risk identification for parts, compositions, and systems is carried out through failure mode effects analysis (FMEA) as one of the most reliable methods. FMEA is a design tool for the failure mode of risk identification and relies on the RPN (risk priority number). FMEA has disadvantages because its severity, occurrence, and detectability are rated at the same level. Fuzzy FMEA applies fuzzy logic to compensate for the shortcomings of FMEA. The fuzzy logic of Fuzzy FMEA is to express uncertainties about the phenomenon and provides quantitative values. In this paper, Fuzzy FMEA is applied to the failure mode of a rotorcraft landing system. The Fuzzy rule and membership functions were conducted in the Fuzzy model to study the RPN in the failure mode of a landing system. This method was selected to demonstrate crisp values of severity, occurrence, and detectability. In addition, the RPN was obtained. The results of Fuzzy FMEA for the landing system were analyzed for the RPN and ranking by fuzzy logic. Finally, Fuzzy FMEA confirmed that it could use the data in quality assurance activities for rotorcraft.

Design and Implementation of Machine Learning-based Blockchain DApp System (머신러닝 기반 블록체인 DApp 시스템 설계 및 구현)

  • Lee, Hyung-Woo;Lee, HanSeong
    • Journal of Internet of Things and Convergence
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    • v.6 no.4
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    • pp.65-72
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    • 2020
  • In this paper, we developed a web-based DApp system based on a private blockchain by applying machine learning techniques to automatically identify Android malicious apps that are continuously increasing rapidly. The optimal machine learning model that provides 96.2587% accuracy for Android malicious app identification was selected to the authorized experimental data, and automatic identification results for Android malicious apps were recorded/managed in the Hyperledger Fabric blockchain system. In addition, a web-based DApp system was developed so that users who have been granted the proper authority can use the blockchain system. Therefore, it is possible to further improve the security in the Android mobile app usage environment through the development of the machine learning-based Android malicious app identification block chain DApp system presented. In the future, it is expected to be able to develop enhanced security services that combine machine learning and blockchain for general-purpose data.

Analysis of MASEM on Behavioral Intention of Information Security Based on Deterrence Theory (억제이론 기반의 정보보안 행동의도에 대한 메타분석)

  • Kim, Jongki
    • Journal of Digital Convergence
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    • v.19 no.2
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    • pp.169-174
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    • 2021
  • While the importance of information security policies is heightened, numerous empirical studies have been conducted to investigate the factors that influence employee's willingness to comply organizational security policies. Some of those studies, however, were not consistent and even contradictory each other. Synthesizing research outcomes has been resulted as qualitative literature reviews or quantitative analysis on individual effect sizes, which leads to meta-analyze on whole research model. This study investigated 28 empirical research based on the deterrence theory with sanction certainty, severity and celerity. The analysis with random effect model resulted in well-fitted research model as well as all of significant paths in the model. Future research can include informal deterrent factors and contextual factors as moderator variables.

An improved LEACH-C routing protocol considering the distance between the cluster head and the base station (클러스터 헤드와 기지국간의 거리를 고려한 향상된 LEACH-C 라우팅 프로토콜)

  • Kim, TaeHyeon;Park, Sea Young;Kwon, Oh Seok;Lee, Jong-Yong;Jung, Kye-Dong
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.2
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    • pp.373-377
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    • 2022
  • Wireless sensor networks are being used in various fields. Wireless sensor networks are applied in many areas, such as security, military detection, environmental management, industrial control, and home automation. There is a problem about the limit of energy that the sensor network basically has. In this paper, we propose the LEACH-CCBD (Low Energy Adaptive Clustering hierarchy - Centrailized with Cluster and Basestation Distance) algorithm that uses energy efficiently by improving network transmission based on LEACH-C among the representative routing protocols. The LEACH-CCBD algorithm is a method of assigning a cluster head to a cluster head by comparing the sum of the distance from the member node to the cluster distance and the distance from the cluster node to the base station with respect to the membership of the member nodes in the cluster when configuring the cluster. The proposed LEACH-CCBD used Matlab simulation to confirm the performance results for each protocol. As a result of the experiment, as the lifetime of the network increased, it was shown to be superior to the LEACH and LEACH-C algorithms.