• Title/Summary/Keyword: 정적 안전성

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A Stability Analysis for Vehicle Impact in U-Channel Segmental Concrete Bridges (U-채널 세그멘탈 콘크리트 교량의 차량충돌에 대한 안전성 분석)

  • Choi, Dong-Ho;Na, Ho-Sung
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.6
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    • pp.17-25
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    • 2010
  • This paper studied on stability of the U-channel segmental concrete bridge under vehicle-impact loads. The U-channel bridge has advantages in that it reduces an additional dead load and the edge beams role as a barrier. But it has a dangerous factor which collapses the bridge structure when the edge beams are ruptured. Therefore, it is necessary to verify behaviors of the bridge system under vehicle-impact loads. Static and dynamic vehicle impact simulations were carried out on the basis of AASHTO LRFD design specifications. In case of the static analysis, equivalent static loads specified in the AASHTO codes are loaded on the edge beams and in case of the dynamic analysis, FEM vehicle models are modeled by applying the dynamic test specifications of AASHTO codes. As a result, it is shown that U-channel bridge system has sufficient safety against static and dynamic impact loads specified in the AASHTO LRFD design specifications.

A Study on SW Understanding based on Virtual Execution (가상실행에 기반을 둔 SW의 이해에 관한 연구)

  • 정양재;박성옥;이문근
    • Proceedings of the Korean Information Science Society Conference
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    • 2000.04a
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    • pp.579-581
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    • 2000
  • 다양한 실행경로가 존재하는 실시간 시스템을 이해하기 위해 정적 정보와 함께 동적 정보의 이해가 필요하다. 본 논문은 매개언어 SRL을 사용하여 정적 정보와 동적 정보를 모두 표현할 수 있는 방법을 제안했다. SRL을 통해 표현된 정적 정보와 동적 정보는 많은 시스템 이해 도구에 사용될 수 있다. 또한 동적 정보를 얻기 위한 방법으로 실제 시스템이 아닌 가상기계를 통한 가상실행을 수행함으로써 안전성이 중요한 시스템을 검증이전에 위험부담 없이 검사할 수 있다.

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A Study on Software Static Analysis Method on IEC 62279 (IEC 62279 규격의 소프트웨어 정적분석에 관한 연구)

  • Jin, Zhe-Huan;Li, Chang-Long;Lee, Jae-Ho;Kim, Jae-Sik;Lee, Key-Seo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.4
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    • pp.513-519
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    • 2015
  • Static analysis is one of the software source code analysis tools. 9 static analysis methods of three groups are recommended by international electro-technical commission about software safety related standard in IEC 62279. In this paper we choose the proper static analysis method from IEC 62279 about the train wayside communication system, Shorten the time of railway signalling software development using LDRA tools. And it wil be useful to improve the effective development of the safety-related software.

Free Vibration of Beams with Initial Deflections due to Dead Loads (사하중에 의한 초기처짐을 갖는 보의 자유진동)

  • 이병구;박광규;오상진;모정만
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1994.04a
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    • pp.154-157
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    • 1994
  • 보는 토목, 건축, 기계, 선박, 항공 등 구조공학 분야에서 가장 기본이 되는 구조단위이므로 그에 대한 동적해석 특히 자유진동에 관한 많은 연구들이 발표되고 있다. 이제까지 이러한 연구들은 사항중으로 인한 정적 초기처짐의 영향을 고려하지 않은 논문들이다. 최근 재료과학의 발달로 고강도의 재료가 출현하고 따라서 세장비가 매우 큰 구조물의 시공이 가능하게 되어 정적 처짐이 다소 큰 구조물에서도 정적 안전성을 확보할 수 있게 되었다. 그러나 이러한 경우에 정적 초기처짐은 구조물의 동적거동에 영향을 줄 것으로 생각된다. 본 연구는 문헌[7]에서 유도된 편미분방정식을 이용하여 사하중에 의한 정적 초기처짐을 갖는 보의 자유진동을 지배하는 상미분방정식을 유도하고 이를 수치해석하여 고유진동수와 진동형을 산출하는데 연구목적이 있다.

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Evaluation of the Load Carrying Capacity of Existing Bridges with Long Span Hollow Web Prestressed Concrete Girder by Static Load Test (정적재하시험을 통한 장경간 중공 웨브 PSC 거더교의 내하력 평가)

  • Kim, Seong-Kyum;Jang, Pan-Ki;Jang, Il-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.3
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    • pp.97-102
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    • 2018
  • Conventional PSC I type girders were adversely affected by the self - weight of concrete, anchorage, prestressing. In order to overcome this problem, PSC girder was constructed with a hollow in the web and developed a hollow web PSC type I girder which is applicable to 50 - 70m span by multistage stressing and then actually long span hollow web PSC girder bridge was constructed. In this study, the results of Static Load Test and the Finite Element Analysis of the hollow web PSC I girder bridges were compared and analyzed, and the Load Carrying Capacity and safety of PSC girder bridges were evaluated. The Static Load Test and the numerical analysis results of this bridge showed similar tendency and the behavior of the hollow web PSC I girder was well simulated. The entire girders of the bridges had sufficient Load Carrying Capacity under the live load design condition and the bridges satisfied the safety and confirmed the appropriateness of the construction.

Static Analysis and Improvement Opportunities for Open Source of UAV Flight Control Software (무인비행체 비행제어 Open Source 소프트웨어에 대한 정적분석 및 개선방안)

  • Jang, Jeong-hoon;Kang, Yu-sun;Lee, Ji-hyun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.6
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    • pp.473-480
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    • 2021
  • In this paper, We analyze and present improvements to problems in software quality through Static Analysis for Open Source, which is widely used as the Flight Controller software for small unmanned aerial vehicle drones. MISRA coding rules, which are widely applied based on software quality, have been selected. Static analysis tools were used by LDRA tools certified international tools used in all industries, including automobiles, railways, nuclear power and healthcare, as well as aviation. We have identified some safety-threatening problems across the quality of the software, such as structure of open source modules, analysis of usage data, compliance with coding rules, and quality indicators (complexity and testability), and have presented improvements.

Static Behavior Analysis of Spillway Pier for Dam Safety Evaluation (댐 안전성 평가를 위한 여수로 피어부의 정적 거동 분석)

  • Jang, Bong-Seok;Lim, Jeong-Yeul;Lee, Myung-Kue;Lee, Hyung-Jun
    • Journal of the Korea Concrete Institute
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    • v.19 no.1
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    • pp.11-18
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    • 2007
  • Seismic performance evaluation for dam safety evaluation has been continually conducted. However the behavior analysis for the spillway pier which is known as the weak point of dam is seldom reported. Therefore, this study performed the static loading tests for a prototype structures as elementary tests for the final seismic performance evaluation of dam safety. The prototype of pier structure has 1/20 scale and it adopts to strength model. And cracking loads and ultimate loads of real structures are calculated through numerical analysis using commercial FEM program (ABAQUS). The results of this study show some difference between the results of prototype tests and the results of numerical analysis. Also, the ultimate and cracking loads can be estimated through the prototype loading test and numerical analysis.

A Security-oriented Operation Scheme of FACTS Devices to Cope with A Single Line-faulted Contingency (단일 선로고장시 정적 안전도 향상을 위한 유연송전기기 운전 방안)

  • Lim, Jung-Uk
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.3
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    • pp.149-155
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    • 2004
  • This paper presents how to find proper operating points of FACTS devices to enhance the steady-state security level considering line contigency analysis. Three generic types of FACTS devices such as series controllers, shunt controllers, and series-shunt controllers are introduced and applied to moximize a security margin and to minimize security indices. Security indices related to line flows and bus voltages are utilized and minimized iteratively in this paper. Contingency analysis is performed to detect the most severe single line fault. In various load conditions, FACTS devices are tested to establish appropriate preventive or corrective action without generation re-dispatching or load shedding. The FACTS operation scheme is verified on the IEEE 57-bus system in a line-faulted contingency.

The Experimental Comparison of Fault Detection Efficiency of Static Code Analysis Tools for Software RAMS (소프트웨어 RAMS를 위한 정적기법을 이용한 코드 결함 검출 효율성에 관한 실험적 비교)

  • Jang, Jeong-Hoon;Yun, Cha-Jung;Jang, Ju-Su;Lee, Won-Taek;Lee, Eun-Kyu
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.2493-2502
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    • 2011
  • For Static analysis of software code, an experienced tester prefer detecting defects with using selective static technique. Many cases of static method have been reported such as coding rules, software metrics, defect data, etc. However, many of analysis case only present effectiveness of static analysis, not enough description for how the tester judged to classify code defects used in code analysis and removed them properly for ensure high quality. Occasionally, there are materials to show the effect of through some examples through some examples. But difficult to gain trust, because of not enough detail for application process. In this paper, introduced the static technique commonly used in railway and applied to the real development challenges. And the each of results were compared and analyzed. It is hard to generalize the results of this parer. But can be used and referenced as a case of study.

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