SysML 기반의 안전성과 보안성을 위한 통합 해저드 분석 프로세스

김은비,한혁수 한국정보과학회 2019 정보과학회논문지 Vol.46 No.12

In a safety-critical system, an accident may cause harm to people and the environment. Therefore, it is important to thoroughly analyze potential hazards and elicit safety requirements from the concept phase of the system to be developed. Traditionally, component failure has been considered a major hazard. However, in modern systems, software faults and failed interactions among components are other major hazards that must be considered. As wired/wireless network connection plays a major role in recent systems, cyber security has become a major system safety concern. Such threats from hackers should be considered in hazard analysis. In the past, hazard analysis in safety and threat analysis in security have been treated as independent activities. As reports about the common assets and the complementary features of both techniques have been released, combining these two analysis techniques has attracted interest in the safety area. The major focuses of this study involved the analysis techniques and the assessment methodologies. Prior studies that have combined hazard and threat analyses have not provide systematic processes that can be followed by practitioners, which is a critical inconvenience in developing safety critical systems for the field. In this paper, we propose a hazard analysis process based on SAMM that integrates threats related to safety using SysML diagrams. We applied the proposed process to a remote parking assistance system to evaluate its effectiveness. 안전 필수 시스템(safety critical system)들은 사고가 나면, 사람과 환경에 큰 재난을 가져온다. 따라서 시스템의 개념 단계(concept phase)부터 잠재적인 해저드(hazard)를 철저히 분석하고, 이를 기반으로 안전 요구사항(safety requirement)을 도출하는 것이 중요하다. 안전성 분야에서는 전통적으로 컴포넌트 실패의 가능성을 분석하고 대비해 왔으며, 근래에 들어서는 소프트웨어의 결함과 컴포넌트들 사이의 상호작용으로 인한 실패까지도 해저드 분석에 포함하고 있다. 시스템이 유선/무선 네트워크 등으로 연결되는 것이 일반화 되면서 사이버 보안성(cybersecurity)이 안전성에 큰 영향을 미치게 되었다. 해커들의 공격으로 인하여 시스템이 제어권을 잃으면, 이는 곧 안전성에 치명적인 손실을 가져오기 때문에, 이러한 위협(threat)들도 해저드 분석 시 파악하고 대비해야 한다. 과거에는 안전성의 해저드와 보안성의 위협을 독립적으로 분석하는 것이 일반적이었다. 하지만 두 분야의 분석 기법들에는 공통점이 많고, 상호 보완할 수 있는 부분들이 있다는 것이 파악되면서 이들을 결합하는 연구들이 진행되고 있다. 지금까지 이 분야의 연구들은 주로 분석 기법들의 공동 활용과 심사 방법에 중점을 두어왔다. 해저드 분석과 위협 분석을 기반으로 하는 연구들이 있기는 하지만, 체계적인 프로세스를 제시하지 않아 실무자들이 현장에서 적용하기에 어려움이 많았다. 본 논문에서는 개념 단계에서 해저드와 위협 분석을 체계적으로 통합하기 위해 SysML의 행위와 구조 다이어그램들을 활용하는 SAMM 기반의 해저드 분석 프로세스를 제안한다. 제안한 프로세스의 효용성을 입증하기 위해 원격 주차 지원 시스템에 적용해 보았다.

의료기관의 위험도 분석 조사 - 지역공공의료원을 중심으로

김영애,송상훈,이현진,김태윤 한국의료복지건축학회 2022 의료·복지 건축 Vol.28 No.4

Purpose: The purpose of this study is to analyse the hazard risk by examining the magnitude and severity of each type of hazard in order to mitigate and prepare for disasters in medical facilities. Methods: The hazard risk analysis for hazard types was surveyed for team leaders of medical facilities. The questionnaire analyzed data from 27 facilities, which were returned from 41 Local Medical Centers. Results: When looking at the 'Risk' by category type of hazard, the influence of health safety and fire/energy safety comes first, followed by natural disaster, facility safety, and crime safety. On the other hand, as for 'Magnitude', facility safety and crime safety come first, followed by health safety, fire/energy safety, and natural disasters. Most of the top types of disaster judged to have high hazard in medical facilities are health types. The top five priorities of hazard in medical facilities, they are affected by the geographical and industrial conditions of the treatment area. In the case of cities, the hazard was found to be high in the order of infectious disease, patient surge, and wind and flood damage. On the other hand, in rural areas, livestock diseases and infectious diseases showed the highest hazard. In the case of forest areas, the hazard was high in the order of wildfire, fire accident, lightning, tide, earthquake, and landslide, whereas in coastal areas of industrial complexes, the hazard was high due to fire, landslide, water pollution, marine pollution, and chemical spill accident. Implications: Through the research, standards will be established for the design of hospitals with disaster preparedness, and will contribute to the preparation of preemptive measures in terms of maintenance.

회계정보와 시장정보를 이용한 부도예측모형의 평가 연구

이인로,김동철 한국재무학회 2015 한국재무학회 학술대회 Vol.2015 No.05

본 연구는 부도예측모형을 정보의 원천(information source)을 기준으로 회계모형, 시장모형, 그리고 헤저드모형으로 구분하고 분석대상모형의 부도예측력을 예측표본(out-ofsample) 에서 비교하였다. 회계모형은 분석방법에 따라 판별분석모형과 로짓분석모형으로 분류하였으며, 이 모형을 이용하여 국내기업에 적합한 변수를 새롭게 선정하여 변수의 계수를 재추정하였다. 시장모형은 부도거리(Distance to Default; DD)모형을 이용하였다. 회계정보와 시장정보를 통합하여 부도예측에 이용한 헤저드모형은 기존의 문헌에서 미국기업에 적용하여 선정된 변수를 국내기업에 그대로 적용하여 변수의 계수만을 재추정한 기존의 헤저드모형과 국내기업에 적합하도록 모형을 수정한 새로운 헤저드모형을 이용하였다. 따라서 5개의 부도예측모형의 부도예측력을 비교분석하였다. 위 5개 모형의 부도예측력은 부도적중률(hit-ratio), ROC (Receiver Operating Characteristic) 곡선을 이용한 평가방법, 그리고 분석대상모형에서 산출된 값과 추후 실제 기업부도와의 관계를 패널분석한 정보검증법(information content test), 이 세가지 방법으로 평가되었다. 이 세가지 평가방법에서 일관되게 국내기업에 적합하도록 기존의 모형을 수정한 새로운 헤저드모형이 가장 부도예측력이 높았으며, 미국기업에 적용하여 선정된 변수를 국내기업에 그대로 적용한 헤저드모형, 로짓분석모형, 판별분석모형, 그리고 DD모형순으로 부도예측력이 높게 나타났다. 따라서 본 연구의 새로운 헤저드모형을 국내기업의 부도예측모형으로 제안하고자 한다. This paper evaluates out-of-sample prediction power of bankruptcy prediction models, accounting-based model, market-based model, and hazard model using both accounting and market information. We suggest two new accounting-based models by using multivariate discriminant analysis and logit analysis. Merton(1974)’s distance-to-default(DD) model is employed as market-based-model. We also provide two hazard models. One is obtained by re-estimating coefficients of frequently used U.S. hazard model with Korean data. The other hazard model is built by modifying aforementioned hazard model for Korean firms. Therefore, we compare the predictability of these five bankruptcy prediction models. We assess the performance of these models by calculating hit-ratio, drawing ROC(receiver operating characteristic) curve, and analyzing information contents test. All three different approaches show that modified hazard model for Korean firms is superior to the others. Therefore, we recommend our modified hazard model for Korean firms as a bankruptcy prediction model.

화학물질배출이동량 자료를 활용한 화학물질배출량 및 유해기반지수 정량화와 시공간 특성 연구

임유라(Yu-Ra Lim),간순영(Sun-Yeong Gan),배현주(Hyun-Joo Bae) 한국환경보건학회 2022 한국환경보건학회지 Vol.48 No.5

Background: The constant consumption of chemical products owing to expanding industrialization has led to an increase in public interest in chemical substances. As the production and disposal processes for these chemical products cause environmental problems, regional information on the hazard level of chemical substances is required considering their effects on humans and in order to ensure environmental safety. Objectives: This study aimed to identify hazard contribution and spatiotemporal characteristics by region and chemical by calculating a hazard-based result score using pollutant release and transfer register (PRTR) data. Methods: This study calculated the chemical discharge and hazard-based result score from the Risk- Screening Environmental Indicators (RSEI) model, analyzed their spatiotemporal patterns, and identified hotspot areas where chemical discharges and high hazard-based scores were concentrated. The amount of chemical discharge and hazard-based risk scores for 250 cities and counties across South Korea were calculated using PRTR data from 2011 to 2018. Results: The chemical discharge (high densities in Incheon, Daegu, and Busan) and hazard-based result scores (high densities in Incheon, Chungcheongnam-do, and some areas of Gyeongsangnam-do Province) showed varying spatial patterns. The chemical discharge (A, B) and hazard-based result score (C, D) hotspots were identified. Additionally, identification of the hazard-based result scores revealed differences in the type of chemicals contributing to the discharge. Ethylbenzene accounted for ≥80% of the discharged chemicals in the discharge hotspots, while chromium accounted for >90% of the discharged chemicals in the hazard-based result score hotspots. Conclusions: The RSEI hazard-based result score is a quantitative indicator that considers the degree of impact on human health as a toxicity-weighted value. It can be used for the management of industries discharging chemical substances as well as local environmental health management.

우리나라에서 "道德的 解弛"의 槪念과 그 問題點

盧應源 한국경제학회 2002 經濟學硏究 Vol.50 No.1

외환위기 이후 많은 사람들이 '모럴 해저드'(道德的 解弛) 현상을 지적해 왔으나 그 대부분이 이 용어를 잘못 사용하고 있는 것으로 분석된다. 특히, 경제학자나 경제관료 등 경제전문가의 오류도 적지 않으며, 그 오류를 지적하는 전문가조차 오류를 내포하고 있는 설정이다. 이러한 몰이해는 국내적으로 경제상황의 진단과 정책처방에서 혼란을 야기하며, 국제적으로 심각한 의사소통 장애를 초래할 수 있다. 본고는 보험업계 전문 용어로서의 "모럴 해저드"의 원래 의미와 경제학에서의 그 의미의 확장 및 변천 과정을 고찰하고, 간단한 경제모형을 통해 그 발생조건과 효과 등을 고찰함으로써 그 의미를 명료하게 설명한다. 그리고 이 개념에 입각하여 한국 언론 및 사전들의 誤用 事例를 분석한다. "Moral hazard" has been pointed out as one of the main caused of Korean economic crisis in 1997. However, the term has often been used inappropriately in Korea to imply "immoral behavior". It is surprising to find that some of well-known economists and high-ranking public officials in economic profession make the same errors, and even more surprising to find that some do so when warning against wrong uses of the term. Misunderstanding of this term may lead to a serious confusion in the diagnosis of economic problem and in the discussion of economic policy, and communications problems in international relationships. The causes of such a misconception are not clear. One may note that the term is inappropriately translated into Korean as "slackened morality." The paper makes clear the meaning of "moral hazard." First, it traces the historical process by which its meaning has changed from a jargon in insurance industry to the current version in economics. Second, a simple model of moral hazard is added to show its causes and effects. Third, it shows empirical evidences of the misuses of the term by Korean news papers and dictionaries.

건강보험에서 피보험자와 의료서비스 공급자 양쪽의 도덕적 해이가 의료서비스 이용에 미치는 영향

홍지민 ( Jimin Hong ) 한국보험학회 2018 保險學會誌 Vol.115 No.-

본 연구는 건강보험에서의 도덕적 해이 문제가 피보험자 및 의료서비스 공급자 각각에게 존재하거나, 양쪽 모두에게 존재할 때 최적보험을 살펴보고 있다. 그 결과 첫째, 양자 모두에게 도덕적 해이가 존재하지 않는 경우 최적보험은 완전보험이다. 둘째, 피보험자에게만 도덕적 해이가 존재하는 경우 일부보험이 최적이다. 반면 의료서비스공급자에게만 도덕적 해이가 존재하는 경우 완전보험이 최적이다. 한편 이때의 의료서비스 이용량은 효용함수 및 건강회복도, 의료서비스 공급자의 비용함수 등에 따라 전자 또는 후자가 더 클 수 있다. 셋째, 보험자가 의료서비스 공급자의 도덕적 해이를 통제하기 위해 진료비 체계를 디자인할 수 있다면 도덕적 해이를 줄이기 위해서는 고정 보수를 지급하는 방식이 최적이다. 그러나 이는 공급자의 노력을 감소시켜 의료서비스를 과소 공급하는 문제를 불러일으킬 수 있다. 넷째, 양자에게 도덕적 해이가 존재한다면, 이 경우의 의료서비스 이용량은 피보험자 또는 의료서비스 공급자 한쪽에만 도덕적 해이가 존재하는 경우에 비해 높거나 낮을 수 있다. 특히 양쪽의 효과가 서로 상쇄되어 더 낮아질 수 있어 도덕적 해이를 단순히 과잉진료의 문제로 보기 어렵다는 것을 의미한다. This study analyzes the optimal insurance contract in health insurance when moral hazard exists in insureds and medical service providers. Three cases are considered: when moral hazard exists only in insureds, when moral hazard exists only in medical service providers, when moral hazard exists in both sides. We first find that the optimal insurance is full insurance without moral hazard. Second, the optimal insurance is partial insurance in the first case, whereas full insurance is optimal in the second case. The medical service consumption of the former case can be greater or less than that of the latter case depending on the utility function, health recovery and cost function of the providers. Third, the insurer can design the treatment fee system, then the fixed payment system is optimal to reduce moral hazard of the providers. Howerver, the system may decrease the provider’s effort and consequently, the supply of medical service may decrease as well. Lastly, the consumption of medical service for the last case can be greater or less than that of the other cases. In particular, it is difficult to regard the moral hazard as the overtreatment since the effect of moral hazard of both sides can be offset.

안전 필수 시스템의 개념단계 해저드 분석 프로세스를 위한 SysML 적용 방안

김은비,한혁수 한국정보과학회 2018 정보과학회논문지 Vol.45 No.7

Today, the accident of safety critical system may result in catastrophic harm to people and environments. Therefore, activities designed to ensure safety, such as identifying the hazard and mitigating risks to prevent those accidents, need to be enforced in system development, especially at the concept phase. PHL and PHA can be hired to identify preliminary hazards and to do Failure Modes and Effects Analysis (FMEA), Fault Tree Analysis (FTA) to assess the causes and impacts of those hazards. For developers and safety experts to work together in the lifecycle, those safety activities need to be integrated into the modelling of system development. The common modelling language, SysML, has been recognized as a solution for this purpose and several types of research on this topic have been published. However, not much effort has been made to apply requirements diagram to acquire the visibility and traceability of safety requirements derived from those hazards identified by analyzing SysML diagrams at concept phase, with related artifacts such as implementation and verification. In this paper, we propose a hazard-identification process in which behavior and structure diagrams of SysML could be systematically analyzed. Then the safety requirements were derived to remove or mitigate the identified hazard. To demonstrate the capability of the proposed process, an example of applying it to an elevator system is presented. 오늘날 안전 필수 시스템(Safety Critical System)들은 사고가 나면, 사람과 환경에 큰 재난을 가져올 수 있기 때문에, 이를 예방하기 위해서는 철저한 안전성 확보 노력이 필요하다. 전체 개발 생명주기에서 해저드를 파악하고 사고 예방을 위한 안전 활동을 강화해야만 한다. 특히 개념 단계부터 잠재적인 해저드를 분석하고, 그 리스크를 완화하는 방안을 설계와 구현에 반영하는 것이 중요하다. 이를 위해서는PHL, PHA 등의 기법을 활용하여, 예비 해저드를 파악하고, FMEA, FTA 등의 기법을 활용하여 영향도를 분석하고, 원인을 식별하는 활동들을 해야한다. 안전 전문가들과 개발자들이 이러한 안전 활동들을 시스템 개발 단계별로 수행하기 위해서는 시스템 모델링에 안전 활동들을 통합하는 것이 바람직하다. SysML의 다이어그램들은 이러한 목적에 적합한 모델링 방법으로 인정받고 연구되어 왔다. 하지만, 개념단계에서 SysML 기반의 해저드 분석을 통해 도출된 안전 요구사항과 구현 및 검증 등 산출물과의 관계에 대한 가시성과 추적성 확보를 위해 요구사항 다이어그램을 적용하는 연구는 이루어지지 않고 있다. 본 논문에서는 개념단계의 해저드 분석을 위해 SysML의 행위와 구조 다이어그램들을 활용하는 방안을 제시한다. 또한 해저드를 제거 또는 완화하기 위한 안전 요구사항을 도출하고, 이를 요구사항 다이어그램에 반영하기 위한 프로세스를 제안한다. 제안한 프로세스의 효용성을 입증하기 위해 엘리베이터 시스템에 적용해보았다.

A Study on the Design Base Accidents Scenario of Non-Reactor Facilities

Dong-Jin Kim,Seong-Hyeon Lee,Byung-Sik Lee 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.1

The decommissioning of Kori unit 1 is just around the corner. Accordingly, it is required to construct a hot cell facility for decommissioning nuclear power plants to analyze the characteristics of intermediate-level waste and low-level waste generated in the decommissioning process. In this study, a Design Base Accident (DBA) scenario of the facility is developed. To identify and characterize potential hazards at the facility, a Preliminary Fact Sheet (PFS) is filled out and consider external events in consideration of the surrounding site environment. The external event screening and evaluation method is based on the external event evaluation method covered in the probabilistic risk assessment. In PFS, only natural and artificial hazards that may have a meaningful impact on the facility are considered as the sources of the accident, and accident prevention and mitigation systems, etc., which exist in each compartment or facility, are described. Based on PFS and external events, potential hazard assessment is systematically performed using each potential hazards, impact and defense function identified using the preliminary hazard analysis (PHA) methodology. The potential hazard analysis methodology applied to this assessment is a qualitative assessment method consistent with the US DOE Hazard Analysis methodology (DOE 1992b; DOE 1994b). After that, the potential mitigation functions that can be used under normal, abnormal and accident conditions are examined, and the contribution of public and workers to safety is evaluated. The results of the PHA are basic data that prioritize potential hazards and can be used to develop potential accident scenarios. Among potential hazards generally considered for non-reactor facilities, only possible accidents during operation of the facilities are selected as potential hazards. The level of potential hazards is obtained by qualitatively examining the frequency and consequence estimates for each hazard or accident scenario developed in PHA. Based on the results of the potential hazards assessment, representative accidents that require further quantitative analysis are screened. Selected accidents are DBA and are the most dangerous and most significant impacts on workers.

Quantitative Hazard Analysis of Information Systems Using Probabilistic Risk Analysis Method

이영재,김태호 한국데이터전략학회 2009 Journal of information technology applications & m Vol.16 No.3

Hazard analysis identifies probability to hazard occurrence and its potential impact on business processes operated in organizations. This paper illustrates a quantitative approach of hazard analysis of information systems by measuring the degree of hazard to information systems using probabilistic risk analysis and activity based costing technique. Specifically the research model projects probability of occurrence by PRA and economic loss by ABC under each identified hazard. To verify the model, each computerized subsystem which is called a business process and hazards occurred on information systems are gathered through one private organization. The loss impact of a hazard occurrence is produced by multiplying probability by the economic loss.

Quantitative Hazard Analysis of Information Systems Using Probabilistic Risk Analysis Method

Lee, Young-Jai,Kim, Tae-Ho Korea Data Strategy Society 2009 Journal of information technology applications & m Vol.16 No.3

Hazard analysis identifies probability to hazard occurrence and its potential impact on business processes operated in organizations. This paper illustrates a quantitative approach of hazard analysis of information systems by measuring the degree of hazard to information systems using probabilistic risk analysis and activity based costing technique. Specifically the research model projects probability of occurrence by PRA and economic loss by ABC under each identified hazard. To verify the model, each computerized subsystem which is called a business process and hazards occurred on information systems are gathered through one private organization. The loss impact of a hazard occurrence is produced by multiplying probability by the economic loss.