• 대한조선학회논문집
• /
• 제47권1호
• /
• pp.76-87
• /
• 2010

According to the new rules and regulations (New SOLAS), major safety critical systems are to be designed to be redundant, which is called 'Redundancy Design'. This paper was to quantitatively analyze the degree of influence of the redundancy design applied to major safety critical systems using IMO's FSA(formal Safety Assessment) method. For the purpose of this study, the diesel engine system, which is actually one of major safety critical systems, was dealt with FMEA, FTA and ETA technique. In addition, whether the redundancy was met or not was verified and the degree of safety, or redundancy, was represented in terms of reliability. In conclusion, the safety of propulsion systems is possibly assessed systematically by estimating the risk level in terms of frequency and fatality.

• 정보보호학회논문지
• /
• 제26권3호
• /
• pp.745-756
• /
• 2016

개인정보 침해사고가 잇따르고 그 피해규모가 심각함에 따라 정부에서는 개인정보의 보호를 위하여 다수의 개인정보보호 관련 인증제도를 도입하였다. 그중에서도 PIMS와 PIPL은 서로 유사한 점이 많아 중복규제라는 문제점이 제기되어 왔다. 본 연구에서는 그동안 논란이 되어 온 PIMS와 PIPL 간의 중복성을 규명하기 위하여 두 인증제도 심사기준의 중복성을 구문분석을 통해 평가한다.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1993년도 가을 학술발표회논문집
• /
• pp.240-247
• /
• 1993

The precise prediction of reserved carrying capacity of bridge as a system is extremely difficult especially when the bridges are highly redundant and significantly deteriorated or damaged. This paper is intended to propose a new approach for the evaluation of reserved system carrying capacity of bridges in terms of equivalent system-strength, which may be defined as a bridge system-strength corresponding to the system reliability of the bridge. This can be derived from an inverse process based on the concept of FOSM form of system reliability index. It may be emphasized that this approach is very useful for the evaluation of the deterministic system redundancy and reserve strength which are measured in terms of either probabilistic system redundancy factor and reserve factor or deterministic system redundancy factor and reserve factor. The system reliability of bridges is formulated as a parallel-series model obtained from the FAM(Failure Mode Approach) based on the major failure mechanisms. AFOSM and IST methods are used for the reliability analysis of the proposed models. The proposed approach and method for the system redundancy and reserve safety/strength are applied to the safety assessment of actual RC and steel box-girder bridges. The results of the evaluation of reserved system safety or bridge system-strength in terms of the system redundancy and the system safety/strength are significantly different from those of element reliability-based or conventional methods.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
• /
• pp.468-471
• /
• 2012

본 논문은 우주발사체에 사용되는 추진기관의 성능평가를 수행하기 위한 지상연소시험설비의 이중화 또는 삼중화 제어시스템의 구축 방안을 다루고 있다. 이중화된 제어시스템의 경우 수동제어 콘솔을 설치하여 삼중화 제어시스템을 모사할 수 있었고, 운용자들의 무분별한 조작을 통제하기 위한 제어실 내 제어 콘솔의 배치 안을 제시하였다.

• 한국멀티미디어학회논문지
• /
• 제25권6호
• /
• pp.793-806
• /
• 2022

As the IMO introduced MASS (Maritime Autonomous Surface Ships), ISO(International Organization for Standardization) announced ISO 19847 of a maritime data sharing standard for collecting and remotely managing data of ship systems. Previous literature evaluated the risk using HAZOP for ISO 19847 and proved that risk assessment is useful through experiments. However, redundancy of ISO 19847 ship data server which is one of the risk reduction method suggested in previous literature, was designed but couldn't tested due to the limitations of the conditions. So, in this study, to prove the usefulness of the ship data server redundancy of ISO 19847 which was not tested in previous literature. It based on the design of previous literature, and the network of ship data servers was modeled using the SES/DEVS format and simulated using the DEVS# open source library.

• 환경영향평가
• /
• 제22권3호
• /
• pp.265-276
• /
• 2013

This study assessed documentation status of each environmental assessment items by analyzing the 243 case of marine EIS on the Consultation System of Sea Area Utilization. Observed rate of tidal elevation, current, temperature, salinity in maine environment were below 20%. The EFDC tool is applied substantially in hydrodynamic modeling. The verification process, however, is very insufficient using the recent observed data. Also, in-situ assessment rate of pelagic organism such as phytoplankton was below 50%, and assessment for Chlorophyll a was not accomplished. Ecological index evaluation for zooplankton and benthic ecosystem were not considered in statements. Especially, the rational assessment on the fisheries resources and protected species were very limited. It was necessary that the core assessment items (checklists) were established for environmental scoping. Furthermore, suggestion of information related to development, regional coastal management plan, aquaculture farms, and facilities were enhanced. The redundancy problem of proceedings between Environmental Impact Assessment and Sea Area Utilization Assessment System was improved.

• 한국지진공학회논문집
• /
• 제24권3호
• /
• pp.141-148
• /
• 2020

For the important safety system, two or more units of identical equipment or redundant components with similar function were installed to prevent abnormal failure. If the failure probability of such equipment is independent, this redundancy could increase the system safety remarkably. However, if the failure of each component is highly correlated by installing in a structure or experiencing an earthquake event, the expected redundancy effect will decrease. Therefore, the seismic correlation of the equipment should be evaluated quantitatively for the seismic probabilistic safety assessment. The correlation effect can be explained in the procedure of constructing fragility curves. In this study, several methodologies to quantify the seismic correlation in the failure probability calculation for multiple components were reviewed and two possible ways considering the realistic situation were selected. Simple examples were tested to check the applicability of these methods. The conversion method between these two methods was suggested to render the evaluation using the advantages of each method possible.

• 한국소프트웨어감정평가학회 논문지
• /
• 제15권1호
• /
• pp.79-86
• /
• 2019

데이터의 차원축소는 요소들의 공통성을 파악해 영향력 있는 중요한 특징 요소를 추출하여 간소화함으로써 복잡함을 줄이고 다중 공선성 문제를 해결한다. 그리고 중복 및 노이즈 검출을 함으로써 불필요함을 줄인다. 이에 본 논문에서는 PCA(Prinicipal Component Analysis)을 적용한 결함 심각도 기반 차원 축소 모델을 제안한다. 제안된 모델은 결함 심각도가 있는 NASA 데이터 세트인 PC4에 적용하여 결함 심각도에 영향을 주는 속성의 차원수를 검증한다. 그 다음 데이터의 차원을 축소한 후 비교 분석한다. 실험결과, PC4의 적합한 차원수는 2~3개였고 그룹화를 통해 차원 축소가 가능한 것을 보였다.

• Structural Engineering and Mechanics
• /
• 제6권5호
• /
• pp.543-554
• /
• 1998

Space truss structures may be fabricated in any of several common grid configurations. With different configurations, the truss performance varies considerably affecting both its competitiveness and suitability for specific applications. The work presented in this paper is an assessment of the most commonly adopted truss configurations and their effect on truss characteristics such as the stiffness/weight value, member stress distribution, number of joints and members, degree of redundancy and cost. The study is parametric and covers wide variations of truss aspect ratios, boundary conditions and span/depth ratios. The results of this study could be of significant value to the design of space truss structures.

• Clinics in Shoulder and Elbow
• /
• 제19권3호
• /
• pp.155-162
• /
• 2016

Background: The study aimed to determine the type of capsular insertion and the extent of capsular elongation in anterior shoulder instability by quantitatively evaluating their computed tomography arthrographic (CTA) findings, and to investigate the correlation of these parameters with surgical outcomes. Methods: We retrospectively reviewed 71 patients who underwent CTA and arthroscopic capsulolabral reconstruction for anterior shoulder instability between April 2004 and August 2008. The control group comprised 72 patients diagnosed as isolated type II superior labrum anterior to posterior (SLAP) lesion during the period. Among the 143 patients, 71 were examined with follow-up CTA at an average 13.8 months after surgery. It was measured the capsular length and cross-sectional area at two distinct capsular regions: the 4 and 5 o'clock position of the capsule. Results: With regards to the incidence of the type of anterior capsular insertion, type I was more common in the control group, whereas type III more common than in the instability group. Anterior capsular length and cross-sectional area were significantly greater in the instability group than in the control group. Among patients of the instability group, the number of dislocations and the presence of anterior labroligamentous periosteal sleeve avulsion lesion were significantly associated with anterior capsular redundancy. Postoperatively, recurrence was found in 3 patients (4.2%) and their postoperative capsular length and cross-sectional area were greater than those of patients without recurrence. Conclusions: Capsular insertion type and capsular redundancy derived through CTA may serve as important parameters for the management of anterior shoulder instability.