• Title/Summary/Keyword: System resilience

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New Security Layer for OverLay Networks

  • Imai, Hideki;Shin, Seong-Han;Kobara, Kazukuni
    • Journal of Communications and Networks
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    • v.11 no.3
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    • pp.211-228
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    • 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.

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

  • Kim, Mi-Ok
    • Korean Journal of Social Welfare
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    • v.60 no.2
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    • pp.99-129
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    • 2008
  • This study analyzed the resilience process of persons with disabilities using the grounded theory approach. To conduct this study, the researcher conducted in-depth interviews with 8 persons with disabilities. In data analysis, this study identified 393 concepts on the resilience process of persons with disabilities and the concepts were categorized into 45 sub-categories and 18 primary categories. In the paradigm model on the resilience process of persons with disabilities, it was identified that casual conditions included 'unawareness of disability before being disability', 'extreme pain', 'repressing psychological pain', and the contingent conditions were 'dis-empowerment by staying in home', 'isolation by himself with difficulty in accepting the disability', 'experience of frustration from social barriers with prejudice against persons with disabilities'. Also, it was identified that the resilience process could be dependent on the type and the degree of the disability, the gender, and the length of time being disability. In spite of the casual and contingent conditions, the central way in which persons with disabilities could acquire resilience was identified as 'enhancement of the power of positive thinking'. The control conditions which accelerate or retard central phenomenon were 'the awareness of not being alone through family, friends, neighborhood and the social system' externally and 'finding purpose in life through religion and help from other persons with disabilities', internally. The action/interactional sequences enhanced the efforts, self searching and active acting, and as a result, persons with disabilities could find comfort in life, participate in society and change the perspective of disability in society. The core categories of resilience process in persons with disabilities were a belief in affirmation and choice of life by initiative. In the process analysis, stages developed in the following: 'pain', 'strangeness', 'reflection', 'daily life'. This stage was more continuous and causal than discrete and complete. In this process, the types of resilience of persons with disabilities are divided into 'existence reflection', 'course development', 'implicit endeavor', and 'active execution'. This study showed the details of the paradigm models, the process and types with an in-depth understanding of the resilience process of persons with disabilities using grounded theory as well as theory construction and policy and clinical involvement on the study of persons with disabilities.

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

  • 김동옥;최원경;김은애
    • Journal of the Korean Society of Clothing and Textiles
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    • v.26 no.2
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    • pp.355-363
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    • 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.

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

  • Kim, Min-Ji;Park, Jung-Woo;Lee, Shin-Hee
    • Fashion & Textile Research Journal
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    • v.6 no.5
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    • pp.660-666
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    • 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
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    • v.42 no.5
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    • pp.748-760
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    • 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

  • Lee, Hye-Kyung
    • Journal of KIBIM
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    • v.9 no.1
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    • pp.32-41
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    • 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.

A Study on the Organizational Resilience of Netflix

  • Song, Minzheong
    • International Journal of Internet, Broadcasting and Communication
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    • v.14 no.3
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    • pp.40-50
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    • 2022
  • The purpose of this study is to prove the global OTT, Netflix's organizational resilience (OR). For this, we review previous literatures regarding Netflix's OR and the theoretical logic of the OR. Then, we investigate Netflix's organizational culture (OC), corporate structure and business strategies based on the five levers of the OR. As a result, the first lever, the coordination makes Netflix to get rid of the inner wall by creating Netflix terms like 'sunshining,' and 'postmortem,' which makes their employees extraordinarily candid with each other. The second lever, the cooperation provides employees with understanding customers by sharing company and service information openly and broadly through transparent board system, billboard advertising, etc. The third lever, the clout allows Netflix to encourage independent decision-making by their employees. Netflix customers are under scrutiny and served 24/7 via live chat or phone by supporting a high-performance workplace. The fourth lever, the capabilities are related to Netflix's keeping highly effective people and it establishes a culture of highly motivated employees. The "dream team" policy is run by what is known as the "keeper test." The last lever, the connections make Netflix to forge external strategic partnership to stay agile. There is no rule for partnering with key content producers by allowing creative freedom to them.

Mobilizing Informal Economic Sector to Uphold Urban Institutional Resilience: A Case Study of Rawalpindi, Pakistan

  • RIAZ, Tayyaba;WAHEED, Abdul;ALVI, Shahzad
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.5
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    • pp.397-407
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    • 2022
  • The informal economy is a large part of the urban economy. The informal economy accounts for about half of Pakistan's GDP. This research examined nine different areas of Rawalpindi's Central Business District's business sector (CBD). A survey of 404 respondents from 16 CBD marketplaces enables a comprehensive examination of who works in the informal and formal economic sectors, how much they earn, their goals, perception of their job, and their degree of similarity to the rest of the working population. Furthermore, the statistics illustrate the pro-cyclical connections between the informal economic sector and the formal economy. The Multinomial Logistic Regression (MLR) technique is used for the analysis. The MLR results indicated the informal economic sector holds positive relation with earning members in a family, business expertise, average business sale, and negative relation with education level, satisfaction with government tax policies, household expense, and average investment in the business. From a resilience standpoint, governance is considered an intentional collective action to preserve a stable system condition. Hence, the current study recommends tax reforms and government institution reorganization to mobilize the informal sector and make effective institutional governance.

Experimental and analytical study of a new seismic isolation device under a column

  • Benshuai Liang;Guangtai Zhang;Mingyang Wang;Jinpeng Zhang;Jianhu Wang
    • Earthquakes and Structures
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    • v.24 no.6
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    • pp.415-428
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    • 2023
  • Low-cost techniques with seismic isolation performance and excellent resilience need to be explored in the case of rural low-rise buildings because of the limited buying power of rural residents. As an inexpensive and eco-friendly isolation bearing, scrap tire pads (STPs) have the issue of poor resilience. Thus, a seismic isolation system under a column (SISC) integrated with STP needs to be designed for the seismic protection of low-rise rural buildings. The SISC, which is based on a simple exterior design, maintains excellent seismic performance, while the mechanical behavior of the internal STP provides elastic resilience. The horizontal behaviors of the SISC are studied through load tests, and its mechanical properties and the intrinsic mechanism of the reset ability are discussed. Results indicate that the average residual displacement ratio was 24.59%, and the reset capability was enhanced. Comparative experimental and finite element analysis results also show that the load-displacement relationship of the SISC was essentially consistent. The dynamic characteristics of isolated and fixed-base buildings were compared by numerical assessment of the response control effects, and the SISC was found to have great seismic isolation performance. SISC can be used as a low-cost base isolation device for rural buildings in developing countries.