• Journal of Advanced Marine Engineering and Technology
• /
• 제40권2호
• /
• pp.112-119
• /
• 2016

Many studies have been conducted on the performance of a passive autocatalytic recombiner (PAR), but not many have focused on the locations where the PAR is installed. During a severe accident in a nuclear reactor containment, a large amount of hydrogen gas can be produced and released into the containment, leading to hydrogen deflagration or a detonation. A PAR is a hydrogen mitigation method that is widely implemented in current and advanced light water reactors. Therefore, for this study, a PAR was installed at different locations in order to investigate the difference in hydrogen reduction rate. The results indicate that the hydrogen reduction rate of a PAR is proportional to the distance between the hydrogen induction location and the bottom wall.

• 한국대기환경학회:학술대회논문집
• /
• 한국대기환경학회 2002년도 춘계학술대회 논문집
• /
• pp.205-206
• /
• 2002

인체의 유해성과 더불어 오존과의 반응성으로 관심의 대상이 되고 있는 대기 환경 중에 VOCs 물질은 최근 약 10여년간 대기 환경 관리에 주요 관심 대강이었으며, 앞으로도 지속적인 노력이 이루어 질 대상이다. 이러한 VOCs는 배출원 및 그 종의 다양성, 그리고 일반적으로 수십 ppb이하의 매우 낮은 농도로 대기 환경 중에 존재하고 있어 측정 및 관리에 어려운 물질이나, 분석기술의 발달과 측정과정에 다양한 방법들이 개발됨에 따라 다양한 종류의 결과들이 발표되고 있다. 특히 이러한 폭정 결과들을 착용하여 이미 MSDS(Material Safety Data Sheets)나 각종 inventory, Database의 구축이 진행되고 있다. (중략)

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2014년도 추계학술대회 논문집
• /
• pp.900-903
• /
• 2014

Fly-wheel, Gimbal antenna, CMG, Spaceborne cyrocooler generate micro-vibration during their on-orbit operation as well as implementing their own function. To comply with the mission requirement of high resolution observation satellite, additional technical efforts have been required to isolate the micro-vibration derived from such payloads by applying the vibration isolator. In this study, we proposed a passive isolator using SMA mesh washer, which guarantees the structural safety of both micro-vibration disturbance source and itself under harsh launch vibration loads without an additional holding mechanism and the micro-vibration isolation performance on orbit environment. To verify the micro-vibration isolation performance of the proposed vibration isolator, we performed the micro-vibration isolation measurement test using the dedicated micro-vibration measurement device proposed in this study.

• Smart Structures and Systems
• /
• 제2권4호
• /
• pp.305-312
• /
• 2006

In the case of hospital buildings, where seismic design requirements are very high, existing structuresand especially those attacked by past earthquakes, appear, often, unable to fulfil the necessary safety prerequisites. In this paper, the retrofitting of hospital buildings is investigated, using alternative methods of repair and strengthening. Analysis of an existing hospital building in Patras, Greece, is performed. The load-bearing system is a reinforced concrete system. Two solutions are proposed: strengthening using concrete jackets around column and beam elements and application of viscoelastic dampers for the increase of the stability of the structure. Adequate finite element models are constructed for each case and conclusions are drawn on the efficiency of each rehabilitation method.

• Nuclear Engineering and Technology
• /
• 제49권4호
• /
• pp.801-809
• /
• 2017

The purpose of this study is to assess the additional neutron effective dose during passive scattering proton therapy. Monte Carlo code (Monte Carlo N-Particle 6) simulation was conducted based on a precise modeling of the National Cancer Center's proton therapy facility. A three-dimensional neutron effective dose profile of the interior of the treatment room was acquired via a computer simulation of the 217.8-MeV proton beam. Measurements were taken with a $^3He$ neutron detector to support the simulation results, which were lower than the simulation results by 16% on average. The secondary photon dose was about 0.8% of the neutron dose. The dominant neutron source was deduced based on flux calculation. The secondary neutron effective dose per proton absorbed dose ranged from $4.942{\pm}0.031mSv/Gy$ at the end of the field to $0.324{\pm}0.006mSv/Gy$ at 150 cm in axial distance.

• 융합보안논문지
• /
• 제11권1호
• /
• pp.19-24
• /
• 2011

센서 모듈을 이용한 물리적인 정보보호 기능을 제공하는 수동 SID 센서 태그를 제안한다. 제안한 보안 센서 태그는 기본적으로 직렬 I/O 인터페이스 모듈, 제어 모듈, 센서모듈로 구성된다. 본 논문에서는, 저항 기반의 센서 신호 데이터를 비교하고 암호화하여 센서 태그의 정보보호 기능을 나타냈다. 제안한 수동형 SID 센서 태그는 상품의 안전, 위조 및 변조 식별, 등을 실시간으로 관리할 수 있다. 또한, 변환기를 이용한 수동형 SID 센서 태그는 광범위한 물리적 정보보호응용에 활용될 것으로 기대한다.

• 전기학회논문지
• /
• 제66권9호
• /
• pp.1373-1378
• /
• 2017

This paper presents a basic ECU(Electronic Control Unit) hardware development procedure for the functional safety of in-vehicle network systems. We consider complete hardware redundancy as a safety mechanism for in-vehicle communication network under the assumption of the wired network failure such as disconnection of a CAN bus. An ESC (Electronic Stability Control) system is selected as an item and the required ASIL(Automotive Safety Integrity Level) for this item is assigned by performing the HARA(Hazard Analysis and Risk Assessment). The basic hardware architecture of the ESC system is designed with a microcontroller, passive components, and communication transceivers. The required ASIL for ESC system is shown to be satisfied with the designed safety mechanism by calculation of hardware architecture metrics such as the SPFM(Single Point Fault Metric) and the LFM(Latent Fault Metric).

• 기술사
• /
• 제19권1호
• /
• pp.3-11
• /
• 1986

The analysis of Geotechnical stability problems by the limit equilibrium method involve assuming the shape of the failure and then investigating many surfaces of the shape to identify the one on which failure seems most likely to occur. These arbitrary assumptions most frequently concern to the locations or directions of side force on slice and the overall factor of safety is considered identical to the local factor of safety. In this paper, let the factor of safety of a slope at wedge block stage differently, when an upper part of the potential sliding mass has a simple active stress field and the lower part of the passive stress field and overall factor of safety is obtained by the average of local factor and computer program based on the modified wedge Method is proposed for this thesis. The new algorithm based on tile modified new method is made for estimating the safety factor of Earth Dam. Compared with conventional method for many cases tile average values of the factor of safety determined by the modified new method are very nearly the same. For all of the cases studied the difference was found 0.03. Finally this new method is thought to be very useful in slope stability analysis.

• 대한기계학회논문집 C: 기술과 교육
• /
• 제1권1호
• /
• pp.49-57
• /
• 2013

해양플랜트의 설계는 위험요인을 정량적 위험성평가를 통해 계량화하여 그 결과를 설계에 반영하는 것이 일반화되어 있다. 대표적인 위험요소인 화재 위험에 대해서도 이는 마찬가지다. 계량화된 화재 위험에 대해 작업자들이 탈출하는 동안 안전설비의 기능을 유지하고 발생된 화재가 더 크게 전이(escalation)되는 것을 방지하는 것이 방화대책의 궁극적인 목적이다. 본 논문에서는 대표적인 방화대책인 능동방화대책과 수동방화대책의 적용사례를 살펴보고 수동방화대책의 설계기법들을 소개한다. 수동방화대책은 효과적인 방화기법이지만 초기 투자비가 많이 소요되고 운용과 유지보수에 애로사항이 크다. 따라서, 최근 들어 발주자들은 수동방화대책을 최적화하도록 해양플랜트 설계자에게 요청하는 추세이다.

• Earthquakes and Structures
• /
• 제11권6호
• /
• pp.1001-1025
• /
• 2016

Building structures generally have inherent low damping capability and hence are vulnerable to seismic excitations. Control devices therefore play a useful role in providing safety to building structures subject to seismic events. In recent years semi-active dampers have gained considerable attention as structural control devices in the building construction industry. Magneto-rheological (MR) damper, a type of semi-active damper has proven to be effective in seismic mitigation of building structures. MR dampers contain a controllable MR fluid whose rheological properties vary rapidly with the applied magnetic field. Although some research has been carried out on the use of MR dampers in building structures, optimal design of MR damper and combined use of MR and passive dampers for real scale buildings has hardly been investigated. This paper investigates the use of MR dampers and incorporating MR-passive damper combinations in building structures in order to achieve acceptable levels of seismic performance. In order to do so, it first develops the MR damper model by integrating control algorithms commonly used in MR damper modelling. The developed MR damper is then integrated in to the seismically excited structure as a time domain function. Linear and nonlinear structure models are evaluated in real time scenarios. Analyses are conducted to investigate the influence of location and number of devices on the seismic performance of the building structure. The findings of this paper provide information towards the design and construction of earthquake safe buildings with optimally employed MR dampers and MR-passive damper combinations.