• 제목/요약/키워드: System resilience

검색결과 331건 처리시간 0.024초

The Impact of Redundancy and Teamwork on Resilience Engineering Factors by Fuzzy Mathematical Programming and Analysis of Variance in a Large Petrochemical Plant

  • Azadeh, Ali;Salehi, Vahid;Mirzayi, Mahsa
    • Safety and Health at Work
    • /
    • 제7권4호
    • /
    • pp.307-316
    • /
    • 2016
  • Background: Resilience engineering (RE) is a new paradigm that can control incidents and reduce their consequences. Integrated RE includes four new factors-self-organization, teamwork, redundancy, and fault-tolerance-in addition to conventional RE factors. This study aimed to evaluate the impacts of these four factors on RE and determine the most efficient factor in an uncertain environment. Methods: The required data were collected through a questionnaire in a petrochemical plant in June 2013. The questionnaire was completed by 115 respondents including 37 managers and 78 operators. Fuzzy data envelopment analysis was used in different ${\alpha}$-cuts in order to calculate the impact of each factor. Analysis of variance was employed to compare the efficiency score means of the four abovementioned factors. Results: The results showed that as ${\alpha}$ approached 0 and the system became fuzzier (${\alpha}=0.3$ and ${\alpha}=0.1$), teamwork played a significant role and had the highest impact on the resilient system. In contrast, as ${\alpha}$ approached 1 and the fuzzy system went toward a certain mode (${\alpha}=0.9$ and ${\alpha}=1$), redundancy had a vital role in the selected resilient system. Therefore, redundancy and teamwork were the most efficient factors. Conclusion: The approach developed in this study could be used for identifying the most important factors in such environments. The results of this study may help managers to have better understanding of weak and strong points in such industries.

ERIS모델 기반 창업지속요인 분석: 조직 리질리언스를 중심으로 (Analysis of Start-up Sustainability Factors Based on ERIS Model: Focusing on the Organization Resilience)

  • 김인숙;양지희
    • 벤처창업연구
    • /
    • 제16권5호
    • /
    • pp.15-29
    • /
    • 2021
  • 본 연구의 목적은 창업성과모델인 ERIS모델과 조직 리질리언스를 중심으로 창업지속요인을 도출하는 것이다. 이를 위해 체계적 문헌고찰과 수정된 델파이 기법을 활용하여 조직 리질리언스를 중심으로 한 ERIS모델 기반 창업지속요인을 분석하였다. 분석결과, ERIS모델 기반 창업지속요인은 창업가, 자원, 산업환경, 전략의 4가지 분류와 하위구분 8개, 세부요인 54개로 분석되었으며 수정된 델파이 기법을 통해 창업지속요인의 적합도를 확인하였다. 또한, 조직 리질리언스를 중심으로 ERIS모델 기반 창업지속요인을 구조화한 결과, 리더십, 문화, 사람, 시스템, 환경의 5가지 분류 아래 ERIS모델에 기반하여 창업지속요인을 구조화하여 통합 프레임웍(ERIS-R)으로 제시하였다. 본 연구의 결과는 다음과 같다. 첫째, 기존 선행연구 분석결과, 다양한 분야의 선행연구에서 창업성공과 창업지속성의 개념이 혼용되어 사용되고 있었다. 둘째, ERIS모델을 기반으로 한 창업성과와 창업지속성에 주요하게 영향을 미치는 요인이 공통적으로 존재함을 확인하였다. 셋째, 조직 리질리언스를 중심으로 창업지속요인에 대한 수정된 델파이 분석 결과, 창업가 개인과 기업의 일반적 특징은 실제로 창업지속성에는 영향을 미치지 않는 것으로 확인되었다. 본 연구는 조직 리질리언스 개념을 중심으로 창업지속요인을 ERIS모델에 기반하여 분석했다는 것과 점차 확장되고 있는 창업 육성·지원 분야에서 ERIS모델에 전략(Strategy)을 시스템(System)으로 포괄하여 조직 리질리언스(Organization resilience)를 R로 연결한 통합 프레임웍(ERIS-R)을 제시했다는 점에서 그 의의가 있다. 본 연구결과를 통해 창업기업에서는 수시로 직면하는 다양한 위기상황에 대해 예측, 예방 및 극복할 수 있는 창업기업 지속성을 높일 수 있으며, 창업기업 지원 기관에서는 창업기업의 지속가능한 경영을 지원할 수 있는 육성 및 지원 정책 개발, 성과관리 등의 기초자료로 활용할 것으로 기대된다.

음의 각을 가지는 허니컴 스포크를 사용한 비 공압타이어의 접지압 분포 (Contact Pressure of Non-Pneumatic Tires with Auxetic Honeycomb Spoke)

  • 김광원;김두만
    • 항공우주시스템공학회지
    • /
    • 제4권2호
    • /
    • pp.1-9
    • /
    • 2010
  • An airless tire has advantages over the conventional pneumatic tire in terms of flat proof and maintenance free. According to the recently disclosed inventions on the airless tire, non-pneumatic tire (NPT) consists of the flexible polygon spokes. Considering the NPT structure, the spokes undergo the tension-compression cyclic loading while the tire rolls. Therefore the spokes of NPT are required to have both stiffness and resilience under the cyclic tensile-compressible loading. In general, if a material has a high stiffness, it shows a low elastic strain limit. In this paper, using the auxetic honeycomb structure with negative poissons's ratio, the spokes of NPT tire are designed to have both stiffness and resilience. Finite element based numerical simulation of the contact pressure of a NPT is carried out with ABAQUS.

  • PDF

New Security Layer for OverLay Networks

  • Imai, Hideki;Shin, Seong-Han;Kobara, Kazukuni
    • Journal of Communications and Networks
    • /
    • 제11권3호
    • /
    • pp.211-228
    • /
    • 2009
  • After clarifying the underlying problems in a secure network storage, we introduce two important requirements, leakageresilience and availability in higher levels respectively, for data keys that are used to protect remotely-stored data. As a main contribution of this paper, we give a new security layer for overlay networks by proposing a leakage-resilient authentication and data management system. In this system, we specifically propose a single mode and a cluster mode where the latter provides a higher level of both leakage-resilience and availability for the data key.

중도장애인의 레질리언스(Resilience) 과정에 관한 연구 (A Study on the Resilience Process of Persons with Disabilities)

  • 김미옥
    • 한국사회복지학
    • /
    • 제60권2호
    • /
    • pp.99-129
    • /
    • 2008
  • 이 연구는 근거이론 방법을 활용하여 중도장애인의 레질리언스 과정을 분석한 것이다. 이를 위해 갑작스러운 사고로 장애를 갖게 된 중도장애인 8명을 심층 인터뷰하였다. 연구 결과, 총 393개의 개념이 도출되었고, 이를 45개의 하위범주, 18개의 상위범주로 유목화할 수 있었다. 중도장애인 레질리언스 과정의 패러다임 모형에서 인과적 조건은 '장애에 대해 모름', '너무 아파 힘듦', 심리적 고통으로 '마음 안으로 숨어듦'인 것으로 나타났다. 맥락적 조건으로는 '집에만 있어 무기력해지고', 장애인정이 어려워 '스스로 장벽을 쌓으며', 장애에 대한 '사회적 장벽'으로 좌절을 경험하는 것으로 나타났다. 또한 장애유형, 장애정도, 성(gender), 장애획득시기, 중도장애 여부 등에 따라 레질리언스에 차이가 있음을 보고하였다. 이러한 인과적 조건과 맥락적 조건에도 불구하고 중도장애인이 레질리언스를 갖게 되는 중심현상은 '긍정의 힘에 탄력이 붙음'으로 확인되었다. 이러한 중심현상을 촉진 혹은 억제하는 중재조건으로는 외적으로 가족, 친구, 주변사람, 제도의 지원을 통해 '혼자가 아님을 깨닫고', 내적으로 종교의 힘과 모델링을 통하여 '변화의 의지와 삶의 목표를 가지고 내일을 준비하는' 것으로 나타났다. 작용/상호작용전략은 '노력을 배가하고', '직접 찾아보며', '능동적으로 실행하기'로 나타났으며 그 결과 중도장애인들은 장애와 사회에 대한 '관점이 달라지고', 삶의 '여유가 생기며', 매사에 '적극적으로 참여함'을 알 수 있었다. 중도장애인 레질리언스 과정의 핵심범주는 '긍정의 힘을 믿으며 주도적으로 나의 삶 선택하기'이었으며, 이는 장애인 레질리언스에서 선택과 자기결정을 통한 주도성의 확보가 매우 중요함을 보여주는 것이다. 과정분석에서는 '고통', '낯섬', '성찰', '일상' 단계로 확인되었으며, 이 단계들은 단선적이기보다는 역동적인 순환과정으로 나타났다. 이 과정에서 중도장애인의 레질리언스 유형은 존재성찰형, 진로개척형, 은근노력형, 적극실행형으로 구분되었다. 또한 개인, 가족 및 친구, 사회 및 제도 차원의 위험 및 보호요인에 관한 상황모형을 정리함으로써, 향후 실천적 개입을 위한 기초 자료를 제시하였다. 본 연구는 국내에서 처음으로 중도장애인의 레질리언스 과정을 근거이론 방법을 활용하여 심층적 이해를 구축하면서 그 과정 및 유형, 상황모형 등을 구체적으로 밝힘으로써 중도장애인 연구에 관한 이론구축 및 정책적, 임상적 개입에 그 함의가 클 것으로 기대한다.

  • PDF

소모직물의 구조적 특성 및 표면특성이 주관적 감각에 미치는 영향 -여성춘추용 수트 직물을 중심으로- (Effect of Structure and Surface Characteristics of worsted Wool Fabrics on the Subjective Hand - Women's Spring -Fall Suit Fabrics -)

  • 김동옥;최원경;김은애
    • 한국의류학회지
    • /
    • 제26권2호
    • /
    • pp.355-363
    • /
    • 2002
  • The purpose of this study was to investigate how the weave type, yarn twist fabric count and fiber content of the worsted fabrics affect the subjective sensation of the hand. Thirty worsted fabrics that were mainly used for the spring and fall ladies'suits at national brands were selected. Variables were such as four different kinds of weave types, plain, twill, satin and decorative; two levels of yarn twist, normal and high; various fabric counts; two different fiber contents, pure wool and Lycra contained. Image analysis and wavelet transform techniques were used to quantify the surface fiber, For surface characteristics, MIU, MMD and SMD were measured by KES-FB system. The Questionnaires with 23 adjectives were used for the subjective hand evaluation. Panels were So specialists of fashion or fabric designers and merchandizers. By Factor Analysis, six factors that represent the subjective hand were extracted. The relationship between these factors and structural variables were analyzed. Yarn twist was significantly related to the surface characteristics and resilience. Weave structure affected surface characteristics, volume/warm-cool feeling and resilience. Fabric counts showed relations with volume/warm-cool feeling and the fiber contents with volume/warm-cool feeling, resilience and elastic properties. MIU, MMD and SMD showed no relations with the surface fibers. Subjective sensation of surface characteristics was affected by SMD and surface fibers.

키토산 가교처리된 면직물의 태 변화에 관한 연구 - 에피클로로히드린과 키토산 농도의 영향- (A study on the Change of Hand of Chitosan Crosslinked Cotton Fabrics - Effect of Concentration of Epichlorohydrin and Chitosan -)

  • 김민지;박정우;이신희
    • 한국의류산업학회지
    • /
    • 제6권5호
    • /
    • pp.660-666
    • /
    • 2004
  • This article describes the change of hand value of chitosan crosslinked cotton fabrics. The chitosan crosslinked cotton fabrics were manufactured by mercerizing process using epichlorohydrin(ECH) as crosslinkins agent, 2% aqueous acetic acid as a solvent of chitosan and ECH, and 20% aqueous sodium hydroxide as a mercerizing agent and crosslinking catalyst. Cotton fabrics were dipped in the mixed solution of chitosan and ECH, picked up by mangle, mercerized and crosslinked in NaOH solution, and finally wash and dry. Mechanical and physical properties of the chitosan crosslinked fabric were investigated using Kawabata Evaluation System(KES) and other instruments. Tensile energy and tensile strain were decreased with the increase of the concentration of chitosan. Tensile resilience, compression resilience bending rigidity, bending hysteresis, shear stiffness, shear hysteresis, coefficient of friction, geometrical roughness, compression linearity, compressional energy, and thickness were increased with the increase of the concentration of chitosan. On the other hand, bending rigidity, bending hysteresis, coefficient of friction, geometrical roughness, compressional resilience, and thickness were increased with the increase of the concentration of crosslinking agent(epichlorohydrin).

Task failure resilience technique for improving the performance of MapReduce in Hadoop

  • Kavitha, C;Anita, X
    • ETRI Journal
    • /
    • 제42권5호
    • /
    • pp.748-760
    • /
    • 2020
  • MapReduce is a framework that can process huge datasets in parallel and distributed computing environments. However, a single machine failure during the runtime of MapReduce tasks can increase completion time by 50%. MapReduce handles task failures by restarting the failed task and re-computing all input data from scratch, regardless of how much data had already been processed. To solve this issue, we need the computed key-value pairs to persist in a storage system to avoid re-computing them during the restarting process. In this paper, the task failure resilience (TFR) technique is proposed, which allows the execution of a failed task to continue from the point it was interrupted without having to redo all the work. Amazon ElastiCache for Redis is used as a non-volatile cache for the key-value pairs. We measured the performance of TFR by running different Hadoop benchmarking suites. TFR was implemented using the Hadoop software framework, and the experimental results showed significant performance improvements when compared with the performance of the default Hadoop implementation.

Resiliency Assessment of Sarasota Bay Watershed, Florida

  • 이혜경
    • 한국BIM학회 논문집
    • /
    • 제9권1호
    • /
    • pp.32-41
    • /
    • 2019
  • As population in Sarasota and Manatee Counties, Florida in the United States is projected to increase, land use changes from land development happen continuously. The more land development means the more impervious surfaces and stormwater runoff to Sarasota Bay, which causes critical impact on the resiliency of the ecosystem. In order to decrease its impact on water quality and the ecosystem function of Sarasota Bay, it is important to assess the resilient status of communities that create negative impacts on the ecosystem. Three types of guiding principles of resiliency for Sarasota Bay watershed are suggested. To assess resiliency status, three indexes - vulnerability index, socio-economic index, and ecological index are developed and analyzed by using geographic information system for each census tract in the two counties. Since each indicator for vulnerability index, socio-economic index, and ecological index is measured with different metrics, statistical standardizing method - distance from the best and worst performers is used for this study to directly compare and combine them all to show total resilience score for each census tract. Also, the ten most and the ten least scores for the total resilience index scores are spatially distributed for better understanding which census tracts are most or least resilient. As Sarasota Watershed boundary is also overlaid, it is easy to understand how each census tract attains its resilience and how each census tract impacts to Sarasota Bay ecosystem. Based on results of the resiliency assessment several recommendations, guidelines, or policies for attaining or enhancing resiliency are suggested.