• Nuclear Engineering and Technology
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• 제35권1호
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• pp.64-79
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• 2003

In the risk and reliability analysis of complex technological systems, the primary concern of formal uncertainty analysis is to understand why uncertainties arise, and to evaluate how they impact the results of the analysis. In recent times, many of the uncertainty analyses have focused on parameters of the risk and reliability analysis models, whose values are uncertain in an aleatory or an epistemic way. As the field of parametric uncertainty analysis matures, however, more attention is being paid to the explicit treatment of uncertainties that are addressed in the predictive model itself as well as the accuracy of the predictive model. The essential steps for evaluating impacts of these model uncertainties in the presence of parameter uncertainties are to determine rigorously various sources of uncertainties to be addressed in an underlying model itself and in turn model parameters, based on our state-of-knowledge and relevant evidence. Answering clearly the question of how to characterize and treat explicitly the forgoing different sources of uncertainty is particularly important for practical aspects such as risk and reliability optimization of systems as well as more transparent risk information and decision-making under various uncertainties. The main purpose of this paper is to provide practical guidance for quantitatively treating various model uncertainties that would often be encountered in the risk and reliability modeling process of complex technological systems.

• 제어로봇시스템학회논문지
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• 제9권10호
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• pp.798-807
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• 2003

We propose a blind mobile robot force control algorithm that uses force information as a guidance toward to the goal position. Based on the mobile robot dynamics, the control law is formed from explicit force errors. Simulation studies are conducted based on the kinematics and the dynamics of the mobile robot. Simulation results show that good force tracking can be achieved. In order to confirm simulation results, experiments are performed. The robot is commanded to follow unknown environment with maintaining a certain desired force. Experimental results show that the blind mobile robot successfully maintains contact with a regulated desired force and arrives at the goal position.

• 산업기술연구
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• 제31권A호
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• pp.3-9
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• 2011

Simulation plays an important role for system analysis. In this study, a manufacturing system has been analyzed through computer simulation. We first briefly explain the considered system with prevailing problems. We then build a simulation model using ARENA simulation language. Based on two selected performance measures, material transporter load and hourly throughput, explicit system analyses have been performed. We addressed four parameters - variation of the processing time, number of raw material transporters, quality failure rate, and machine failures - as the input parameters affecting the output measures selected. We adopted Taguchi's orthogonal array in statistical experimental design and drew meaningful results from the analysis. The results given in the study may provide a good guidance for practical applications.

• 대한기계학회논문집A
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• 제39권8호
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• pp.737-742
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• 2015

탄도 수정탄은 기존의 포탄에 조종 kit를 장착하여 목표를 정밀 타격할 수 있게 하는 무기 체계이다. 롤제어시스템은 조종 kit의 구성품으로 유도조종부와 탄체부 사이에 위치하며 포발사시 횡방향으로 5,000g 상당의 가속도 하중을 받게 된다. 따라서 내고충격 설계를 하는게 중요하다. 선진국에서는 탄도 수정탄의 개발과정에서 실사격 또는 포발사 회수 시스템을 이용하여 부품의 성능 및 강도를 평가하고 있으나 많은 시간과 비용이 든다는 단점이 있다. 따라서 본 연구에서는 CAE 해석적 방법으로 설계단계에서 롤제어시스템에 대한 충격 강도 평가를 할 수 있도록 해석 모델을 개발하였다. 충격 현상을 구현하기 위하여 Explicit code를 이용한 Dynamic 해석 기법을 적용하였고, 고변형률 물성 특성을 Johnson-Cook material model을 이용하여 구현하였다. 또한 베어링을 인너, 아우터 레이스, 리테이너, 볼 등으로 상세적으로 구현하여 충격시 베어링의 거동 특성이 분석될 수 있도록 하였다. 개발된 해석 모델은 가스건 충격시험을 통해 그 신뢰성이 있음을 검증하였다.

• Korean Journal of Acupuncture
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• 제24권4호
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• pp.13-24
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• 2007

Objectives : This article aims to give guidance on the conduct and reporting of case series and audits of acupuncture, based on common problems that have arisen in the past. This type of project, and particularly the prospective case series or pre- post-intervention study, may give valuable evidence of the overall effectiveness of acupuncture-for example in different situations and in different conditions- and provides one step in the research pathway before generating an hypothesis. Results & Discussion : The project should be designed with the aim of reducing bias as much as possible. Careful and detailed planning is essential for the project to produce worthwhile results that readers can evaluate and replicate. Ethical issues should be considered and formal approval may be necessary. The patient group should be recruited systematically and baseline data obtained. The treatment given should be systematic and decisions to change or end treatment made explicit. The outcome should be measured in ways that are known to be reliable and valid. Musculoskeletal problems can be evaluated with scales for pain and confirmed by measuring one other symptom such as stiffness or one other aspect such as bothersomeness. Global change scores also provide supporting information, and the MYMOP (Measure Yourself Medical Outcome Profile) measure is popular when patients with different conditions are included. The design of questionnaires for beliefs and attitudes is a specialised area that should not be attempted without expert help. Adverse events should also be recorded. Analysis of the data and the best way of summarising and presenting the results are also discussed.

• Ocean Systems Engineering
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• 제9권2호
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• pp.191-218
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• 2019

The tower-platform interface and mooring system of floating offshore wind turbines (FOWTs) are some of the most critical components with significant influences on overall project costs. In addition to satisfying strength requirements, it is typical and vital to meet fatigue criteria for a service life of 25 years or more. Wind spectra characteristics considered in analysis can penalize fatigue designs, leading to unnecessary costs. The International Electrotechnical Commission (IEC, 2009) recommends the use of site-specific wind data (spectrum, turbulence intensity, etc.) in design of FOWTs, but for offshore sites it is often the case that such data is unavailable and land-based data are used as surrogates in design. For such scenarios, it is worth investigating whether such alternative approach is suitable and accurate, and understanding the consequence of the selection of wind spectral characteristics on fatigue design. This paper addresses the impact of the subsequent selection on fatigue responses of towerbase and mooring system in a FOWT, as a sequel to the paper by Udoh and Zou (2018) which focused on impacts on strength design. The 5 MW semi-submersible FOWT platform with six mooring lines implemented in the preceding study is applied in analysis. Results indicate significant variations in resulting fatigue life with considered wind parameters. Thus, it is critical to apply proper wind spectra characteristics for analysis and design of FOWTs to avoid unnecessary conservatism and costs. Based on the findings of this study, more explicit guidance on the application of turbulence intensities for IEC-recommended models in offshore sites could lead to more accurate load estimates in design of FOWTs.

• 보건의료기술평가
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• 제1권1호
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• pp.22-26
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• 2013

Objectives: Balancing benefits and risks through the drug life cycle has been discussed for many decades. The objective of this study was to review the processes and tools currently proposed for benefit-risk assessment of medicinal drugs. It aimed to establish scientific and efficient drug safety management system based on the synthetic analysis of benefit-risk evidence. Methods: We conducted a review of exiting literatures published by regulatory agencies or initiatives. Not only quantitative methodologies but also qualitative method were compared to understand their key characteristics for the benefit and risk assessment of drugs. Results: Recently, benefit-risk assessments have more structured approaches to decision making as part of regulatory science. Regulatory agencies such as European Medicines Agency, FDA have prepared plans to apply benefit-risk assessment to regulatory decision making. Also many initiatives such as IMI (Innovative Medicine Initiative) have conducted research and published reports about benefit-risk assessment. For benefit-risk assessment, four kinds of methods are necessary. Frameworks such as BRAT (Benefit Risk Action Team) framework, PrOACT-URL provide guidance for the whole process of decision-making. Metrics are measurements of risk benefit. The estimation techniques are methods to synthesis and combine evidences from various sources. The utility survey techniques are necessary to explicit preferences of various outcome from stakeholders. Conclusion: There is the lack of widely accepted, validated model for benefit-risk assessment. Nor there is an agreement among academia, industry, and government on methods for the quantitative valuation. It is also limited by available evidence and underlying assumptions. Nevertheless, benefit-risk assessment is fundamental to improve transparency, consistency and predictability for decision making through the structured systematic approaches.

• 무역상무연구
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• 제51권
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• pp.317-358
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• 2011

The purpose of this study aims to analyse the key differences of the sea waybill and electronic B/L in the international transport documents. Sea waybills look remarkably like ordinary bills of lading. Indeed, in two important ways, they are just like bills of lading: the front of the document will near a description of the quantity and apparent condition of the goods; and the back of the document provides evidence of the terms of the contract of carriage. They differ from bills of lading in that, far from indicating that the goods described are deliverable to the order of the shipper or of the consignee, they will make it explicit that the goods are deliverable only to the consignee. Again, different carries will do thai in a variety of ways. For example, the document may call itself non-negotiable, omitting the word order from the consignee box on the front of the document, and stating explicitly that the goods will be deliverable to the consignee or his authorised representative on proper proof of identity and authorisation. The Hague-Visby Rules and Hamburg Rules give no guidance as to any right to instruct the carrier in respect of goods while they are in transit. However, in applying Article 50 of the Rotterdam Rules, in particular when applying it in the context of seawaybills, straight bills of lading or ship's delivery orders, regard would need to be had to preserve the shipper's rights under any of those three documents even after the buyer of goods covered by them has acquired rights of its own. And, the right of control is defined at Article 1.12 of the Rotterdam Rules. The right to give instruction is further limited by the terms of Article 50.1 to three particular types of instruction in respect of the goods, relating broadly to the goods, their delivery en route, and the identity of the consignee. And, the CMI formulated the CMI Uniform Rules for Sea Waybills for voluntary incorporation into any contract of carriage covered by such a document. Recognising that neither the Hague nor the Hague-Visby Rules are applicable to sea waybills, the CMI Rules provide that a contract of carriage covered by a waybill shall be governed by whichever international or national law, if any, would have been compulsorily applicable if the contract had in fact been covered by a bill of lading or similar document of title.

• 의료법학
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• 제18권2호
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• pp.105-138
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• 2017

이 글은 환자의 자기결정권에 관한 몇몇 대표적인 판례들을 연혁적으로 검토한 논문이다. 대법원은 과거 음주상태에서 농약을 음독하여 자살을 시도한 환자가 치료를 거부하자 치료를 포기한 의료진에게 특정 의학적 상태(응급상황)에서 의사의 생명보호의무가 환자의 자기결정권 존중보다 우선한다고 판단하여 의료과실을 인정하였다. 이후 대법원은 가족들의 요청에 의해 지속적 식물인간 상태인 환자에게 해당 환자의 의학적 상태(회복불가능한 사망의 단계 등)를 고려하고 환자의 의사를 추정하여 연명의료를 중단하게 하였다. 최근 대법원은 종교적 신념과 관련하여 수혈과 같은 필수적인 치료를 거부한 환자에 대하여 대법원은 환자의 생명 보호에 못지않게 환자의 자기결정권을 존중하여야 할 의무가 대등한 가치를 가지는 것으로 평가할 수 있는 판단 기준을 제시하였다. 인간의 존엄성에 근거한 환자의 자기결정권과 의사의 생명보호의무가 충돌하는 상황에 대하여 연혁적 판례 검토를 통해 법원의 입장이 우리 사회에서 환자의 주체적 역할과 자율성을 존중하는 방향을 반영하여 함께 변화되어 왔음을 확인할 수 있었다. 법원이 생명권이라는 최고의 가치만을 환자의 의사보다 더욱 우선하여 판단해오다가 적어도 명시적인 환자의 의사 또는 그렇지 못할 경우에 추정적 의사까지도 고려한 치료의 유보나 중단에 대하여 고려하기 시작한 것, 종교적 신념에 근거한 자기결정권의 행사로서의 수혈거부와 같은 치료거부에 대하여 충분한 정보에 근거한 치료거부의 몇 가지 적법한 요건들을 인정하기 시작했다는 것은 이후 우리나라 의료 환경에 적잖은 영향을 줄 것이고 의료현장에서 의료행위를 하는 의사들에게도 직 간접적인 지침이 될 것이다.

• 한국지리정보학회지
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• 제14권3호
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• pp.236-256
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• 2011

토지이용변화에 따른 산림탄소저장량 변화는 기후변화협약에서 요구하는 주요 자료 중 하나이다. IPCC 우수실행지침(intergovernmental panel on climate change good practice guidance, IPCC GPG) 수준 3에 근거하여 공간적으로 명확한 산림탄소저장량을 추정하게 되면 높은 신뢰도를 확보할 수 있다. 그러나 기존의 추정 방법은 표본점(sample plot) 단위의 국가산림자원조사 (national forest inventory, NFI) 자료만을 이용하여 행정구역별 평균을 집계하는 것으로 폴리곤 혹은 셀 단위의 상세한 탄소저장량을 파악할 수 없었다. 이를 보완하기 위해 유럽, 북미 등에서는 NFI 자료, 원격탐사 및 GIS 기술을 결합하여 산림탄소저장량을 추정하기 위한 노력이 활발히 이루어져왔다. 주요국의 연구 동향을 활용 기법에 따라 분류해보면 원격탐사, GIS, 지구통계 및 환경변수 모델링 등 크게 4가지 범주로 나눌 수 있다. 이 중 가장 손쉽게 국내 적용을 고려해 볼 수 있는 방법은 NFI 자료와 임상도를 결합하는 GIS 기반의 방법이다. 특히, 복잡한 수종 구성을 가지고 있는 국내 산림 환경 특성을 고려할 때 국지적 변이 추정에 유용한 지구통계 기법의 활용성이 기대된다. 아울러, 고해상도 영상의 활용은 산림탄소저장량 추정의 검증 및 탄소배출권 확보를 위한 CDM(clean development mechanism, 청정개발체제) 사업 적지 선정 등에 유용할 것으로 판단된다. 국내 관련 연구는 아직 초기 단계로 최근린 기법(k-nearest neighbor, k-NN)의 적용성을 검토하는 연구가 주를 이루고 있으나 국내 산림 환경에 적합한 방법론의 선정을 위해서는 보다 다양한 공간 자료와 알고리즘의 적용성이 검토되고 방법론 간의 비교 연구가 필요하다.