• 한국압력기기공학회 논문집
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• 제12권1호
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• pp.56-61
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• 2016

After Japanese Fukushima nuclear power plant accident caused by the beyond design basis earthquake and tsunami, it has turned to be a major challenge for nuclear safety. IAEA, US NRC and EU have provided new safety design standards for beyond design basis event, Domestic regulatory bodies have also enacted guidances for licensees and applicants on additional methods related to beyond design basis events. This paper describes several evaluation methods for applying to nuclear power plants piping for beyond design basis earthquake. As a results, energy method based on the absorbed energy on nuclear power plant, deterministic method following design code and theory, experience method considering past earthquake data and information and probabilistic methods similar to probabilistic risk assessment were reviewed.

• Nuclear Engineering and Technology
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• 제44권3호
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• pp.225-236
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• 2012

The Fukushima-Daiichi accident shook the world, as a well-known plant design, the General Electric BWR Mark I, was heavily damaged in the tsunami, which followed the Great Japanese Earthquake of 11 March 2011. Plant safety functions were lost and, as both AC and DC failed, manoeuvrability of the plants at the site virtually came to a full stop. The traditional system of Emergency Operating Procedures (EOPs) and Severe Accident Management Guidelines (SAMG) failed to protect core and containment, and severe core damage resulted, followed by devastating hydrogen explosions and, finally, considerable radioactive releases. The root cause may not only have been that the design against tsunamis was incorrect, but that the defence against accidents in most power plants is based on traditional assumptions, such as Large Break LOCA as the limiting event, whereas there is no engineered design against severe accidents in most plants. Accidents beyond the licensed design basis have hardly been considered in the various designs, and if they were included, they often were not classified for their safety role, as most system safety classifications considered only design basis accidents. It is, hence, time to again consider the Design Basis Accident, and ask ourselves whether the time has not come to consider engineered safety functions to mitigate core damage accidents. Associated is a proper classification of those systems that do the job. Also associated are safety criteria, which so far are only related to 'public health and safety'; in reality, nuclear accidents cause few casualties, but create immense economical and societal effects-for which there are no criteria to be met. Severe accidents create an environment far surpassing the imagination of those who developed EOPs and SAMG, most of which was developed after Three Mile Island - an accident where all was still in place, except the insight in the event was lost. It requires fundamental changes in our present safety approach and safety thinking and, hence, also in our EOPs and SAMG, in order to prevent future 'Fukushimas'.

• 한국측량학회지
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• 제30권6_1호
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• pp.549-557
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• 2012

환경 오염, 질병과 같은 확산의 위험 정보가 높은 공간 현상들은 신속한 초기 대응이 필요하며 특히 확산의 주체가 되는 이동체 데이터에 대한 실시간 처리와 분석을 통해 확산 요인 이벤트를 감지해야 한다. 이러한 이벤트를 처리하고 분석하기 위해 시공간 복합 이벤트 처리(Spatial-Temporal Complex Event Processing)가 활용된다. 기존의 시공간 복합 이벤트 처리는 기본적인 공간 연산이 가능하나 복잡도가 높은 공간 상황을 감지하는 시공간 복합 이벤트 설계에 적용이 미흡하였다. 본 연구에서는 시공간 복합 이벤트 처리의 공간 연산의 확장을 가능케 하고 복합적인 이벤트 설계 과정에서 효율적으로 이벤트를 관리 하기 위해 계층적 시공간 복합 이벤트 설계를 제안하였다. 제안된 방법으로 축산 관련 차량들 중 구제역 확산과 관련된 차량을 감지하는 새로운 이벤트를 생성하는 실험을 진행하여 제안된 시공간 복합 이벤트 처리의 효용성을 입증하였다.

• 한국시뮬레이션학회논문지
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• 제3권1호
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• pp.75-88
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• 1994

Discrete event modeling is finding ever more application to anlysis and design of complex manufacturing, communication, computer systems, etc. This paper shows how packet network systems may be advantageously represented as DEVS (Discrete Event System Specification) models by employing System Entity structure / Model base (SES/MB) framework developed by Zeigler. DEVS models and network structure representations support a strong basis for performance analysis of packet network systems. This approach is illustated in a typical packet network example with several routing strategies.

• Nuclear Engineering and Technology
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• 제50권6호
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• pp.860-868
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• 2018

This article presents a new design of earthquake instrumentation that is suitable for quick decision-making after the seismic event at the nuclear power plant (NPP). The main objective of this work is to ensure more availability of the NPP by expediting walk-down period when the seismic wave is incident. In general, the decision-making to restart the NPP after the seismic event requires more than 1 month if an earthquake exceeds operating basis earthquake level. It affects to the plant availability significantly. Unnecessary shutdown can be skipped through quick assessments of operating basis earthquake, safe shutdown earthquake events, and damage status to structure, system, and components. Multidecision parameters such as cumulative absolute velocity, peak ground acceleration, Modified Mercalli Intensity Scale, floor response spectrum, and cumulative fatigue are discussed. The implementation scope on the field-programmable gate array platform of this work is limited to cumulative absolute velocity, peak ground acceleration, and Modified Mercalli Intensity. It can ensure better availability of the plant through integrated decision-making process by automatic assessment of NPP structure, system, and components.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2007년도 추계학술발표대회 논문집
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• pp.179-182
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• 2007

2007 Design Festival on Seongnam Living Design has been held with the theme of "You and I, We" on the basis of harmony through design. This kind of theme has the main concepts as follows: Harmony- the exhibition program that can capture our mind, Communication-the experience program not through personal work but through group work, Design Seongnam-joyful Sungnam which we have made together by regional participation design project. Especially, it also has encouraged active and voluntary participation based on the promotion of the event and design exhibition that are hosted by the universities, elementary and secondary schools that represent the downtown Seongnam. In understanding Seongnam City, it has applied the plan introducing emotional process. These are the programs, which are reading, thinking, listening, watching, touching, making, and dreaming. Through the processes of being with Seongnam by participants, it has helped people know more about Seongnam, and focused on being the exhibition understanding the members of the community Seongnam.

• 전기학회논문지
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• 제64권6호
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• pp.922-934
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• 2015

In this paper, The classification between precipitation echo(PRE) and non-precipitation echo(N-PRE) (including ground echo and clear echo) is carried out from weather radar data using neuro-fuzzy algorithm. In order to classify between PRE and N-PRE, Input variables are built up through characteristic analysis of radar data. First, the event classifier as the first classification step is designed to classify precipitation event and non-precipitation event using input variables of RBFNNs such as DZ, DZ of Frequency(DZ_FR), SDZ, SDZ of Frequency(SDZ_FR), VGZ, VGZ of Frequency(VGZ_FR). After the event classification, in the precipitation event including non-precipitation echo, the non-precipitation echo is completely removed by the echo classifier of the second classifier step that is built as Type-2 FCM based RBFNNs. Also, parameters of classification system are acquired for effective performance using PSO(Particle Swarm Optimization). The performance results of the proposed echo classifier are compared with CZ. In the sequel, the proposed model architectures which use event classifier as well as the echo classifier of Interval Type-2 FCM based RBFNN show the superiority of output performance when compared with the conventional echo classifier based on RBFNN.

• 복식
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• 제56권8호
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• pp.148-159
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• 2006

The objective of this study is to consider the uniform as visual communication, and analyze the expression of symbol shown on the uniform design by the pattern by applying the visual symbol in the communication and operation of the meaning. Also, it is to construct the systematic modeling method of the expression of design symbol by the pattern of uniform in th e various fields. This study is to analyze the symbolic expression method of the uniform design by the pattern by suggesting the symbolic expression method as a frame through the visual symbolic approach of the uniform design and the analysis of semantic symbol according to that. As a result, there arose simplification and emphasis and a method of symbolic expression with the national flag, a conceptual factor characteristically in the sports uniform design. The characteristics of symbolic expression of uniform design were mainly used in the symbolic expression with the customary code and symbol. Also, the uniform in the enterprises were widely used in the expression of uniform with the suggestion and code by the color. As for the characteristics of symbolic expression shown on the event uniform design, the method of symbolic expression by the pattern of uniform was grasped differently asa result of symbolic expression through the image. The method of symbolic expression suggested on this study could be used on a basis of uniform design in the future. Accordingly, this study has a meaning of suggesting the methodology of uniform design that would be a parameter.

• 디자인학연구
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• 제14권
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• pp.121-138
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• 1996

전환기적 시대상황의 인식과 뉴 패러다임에 기초하여 미래 건축환경의 변화를 예측하고 그에 대응할 수 있는 건축언어와 새로운 디자인 전략을 제안하는데 본 연구의 목적이 있었으며, 그 연구내용과 결과는 다음과 같다. 첫째, 현대 예술 속에서 공간, 인간의 신체, 그리고 움직임을 재해석하고 그 예술적 의도를 환경디자인과 결합시켜 퍼포먼스·이벤트건축의 가능성을 고찰하였다. 둘째, 건축환경은 물질들만의 집합보다는 공간, 움직임, 우연적 상황 그리고 이벤트들의 결합체로서 보았다. 또한 퍼포먼스장소로서의 환경을 이해함과 동시에 디자인 행위자체를 퍼포먼스 과정으로 제시하였다. 셋째, 인간은 환경과의 상호작용을 통해 항상 반응하며 스스로의 조절을 통해 적응하는 유기체적 시스템이다. 건축 또한 현시대의 불확정적인 인식체계와 빠르게 변화하는 사회구조, 테크놀러지의 발전과 함께 인간의 행위, 활동이 결합되어 끊임없이 변화하는 역동적 시스템으로 설명되었다. 넷째, 본 연구자는 종래 모더니즘 디자인에서의 형태와 기능의 인과론적, 기계론적 조형태도에서 벗어나 상대론 적, 유기론 적 관점을 취하과자 하였다. 특히 탈 물질적인 환경의 개념을 강조하였으며 형태와 기능의 상호 텍스트 성, 그리고 시간의 흐름 속에서 상호변화 가능성을 지원할 수 있는 탈 프로그램 방법을 제안하였다. 결과적으로 퍼포먼스·이벤트건축의 전략은 인간의 자율적 기능의 회복과 예술로서의 환경을 어느 정도 가능하게 할 수 있는 개념이라고 보았으며, 시스템적 세계관으로의 전환을 강조하였다.

• 전력전자학회논문지
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• 제24권3호
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• pp.207-214
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• 2019

In this study, discrete-time domain analysis is proposed to investigate the input current of a buck AC/DC light-emitting diode (LED) driver. The buck power factor correction converter can operate in both discontinuous conduction mode (DCM) and continuous conduction mode (CCM). Two discontinuous and two continuous conduction operating modes are possible depending on which event terminates the conduction of the main switch in a switching cycle. All four operating modes are considered in the discrete-time domain analysis. The peak current-mode control with slope compensation is used to design a low-cost AC/DC LED driver. A slope compensation design of the buck AC/DC LED driver is described on the basis of a discrete-time domain analysis. Experimental results are presented to confirm the usefulness of the proposed analysis.