• Title/Summary/Keyword: Core recovery

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A Study on the Safety Improvement of the High Temperature Ceramic Heat Recovery System (고온 세라믹 폐열회수장치의 안전성 향상 연구)

  • Park, Yong-Hwan;Kang, Young-Goo;Kim, Hong
    • Journal of the Korean Society of Safety
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    • v.11 no.4
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    • pp.107-114
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    • 1996
  • A study to Improve the safety of the ceramic heat exchanger In the high temperature heat recovery system was performed in terms of air flow passes. The numerical and finite element analyses on the heat transfer and thermal stresses in the ceramic core related with air passes were carried out. The results showed that the stresses in the ceramic core induced by the thermal expansion are large enough to cause failure of the brittle ceramic core. The imployment of triple-pass air flow for the same ceramic core could increase the efficiency and effectively release approximately 20% of the maximum thermal stressess, thus improving the safety of the ceramic heat exchanger. The use of triple-pass, however, is limited by the amount of air flow due to the increase of pressure drop.

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A Study on How to Build a Disaster Recovery System that can Minimize Recovery Time Objective(RTO) and Recovery Point Objective(RPO) to Ensure Business Continuity (비즈니스 연속성 보장을 위한 복구 시간 목표(RTO) 및 복구 지점 목표(RPO)를 최소화할 수 있는 재해복구시스템 구축 방안 연구)

  • Kang, Hyun-Sun
    • Journal of Software Assessment and Valuation
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    • v.17 no.2
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    • pp.91-99
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    • 2021
  • In the current business environment where dependence on IT has increased rapidly, the risk from disasters or cyber-attacks is also increasing. Business continuity, the ability to continue to provide service in the event of a business disruption caused by a disaster, is essential. In other words, you need to have a plan in place to keep your core business functions uninterrupted with rapid recovery within a predetermined Recovery Time Objective (RTO) and Recovery Point Objective (RPO) time frame. In this paper, we propose a disaster recovery system construction method that can minimize RTO and RPO to ensure business continuity. The system configuration adopts Tier 7 disaster recovery model, synchronous storage replication, hot disaster recovery site, and operation management automation solution. This ensures continuity of core business with virtually no data loss and minimal RTO and RPO.

An Evaluation of Operator's Action Time for Core Cooling Recovery Operation in Nuclear Power Plant (원자력발전소의 노심냉각회복 조치에 대한 운전원 조치시간 평가)

  • Bae, Yeon-Kyoung
    • Journal of the Korean Society of Safety
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    • v.27 no.5
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    • pp.229-234
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    • 2012
  • Operator's action time is evaluated from MAAP4 analysis used in conventional probabilistic safety assessment(PSA) of a nuclear power plant. MAAP4 code which was developed for severe accident analysis is too conservative to perform a realistic PSA. A best-estimate code such as RELAP5/MOD3, MARS has been used to reduce the conservatism of thermal hydraulic analysis. In this study, operator's action time of core cooling recovery operation is evaluated by using the MARS code, which its Fussell-Vessely(F-V) value was evaluated as highly important in a small break loss of coolant(SBLOCA) event and loss of component cooling water(LOCCW) event in previous PSA. The main conclusions were elicited : (1) MARS analysis provides larger time window for operator's action time than MAAP4 analysis and gives the more realistic time window in PSA (2) Sufficient operator's action time can reduce human error probability and core damage frequency in PSA.

Dynamic Redundancy-based Fault-Recovery Scheme for Reliable CGRA-based Multi-Core Architecture

  • Kim, Yoonjin;Sohn, Seungyeon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.6
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    • pp.615-628
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    • 2015
  • CGRA (Coarse-Grained Reconfigurable Architecture) based multi-core architecture can be considered as a suitable solution for the fault-tolerant computing. However, there have been a few research projects based on fault-tolerant CGRA without exploiting the strengths of CGRA as well as their works are limited to single CGRA. Therefore, in this paper, we propose two approaches to enable exploiting the inherent redundancy and reconfigurability of the multi-CGRA for fault-recovery. One is a resilient inter-CGRA fabric that is ring-based sharing fabric (RSF) with minimal interconnection overhead. Another is a novel intra/inter-CGRA reconfiguration technique on RSF for maximizing utilization of the resources when faults occur. Experimental results show that the proposed approaches achieve up to 94% faulty recoverability with reducing area/delay/power by up to 15%/28.6%/31% when compared with completely connected fabric (CCF).

Sampling and Selection Factors that Enhance the Diversity of Microbial Collections: Application to Biopesticide Development

  • Park, Jun-Kyung;Lee, Seung-Hwan;Lee, Jang-Hoon;Han, Songhee;Kang, Hunseung;Kim, Jin-Cheol;Kim, Young Cheol;McSpadden Gardener, Brian
    • The Plant Pathology Journal
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    • v.29 no.2
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    • pp.144-153
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    • 2013
  • Diverse bacteria are known to colonize plants. However, only a small fraction of that diversity has been evaluated for their biopesticide potential. To date, the criteria for sampling and selection in such bioprospecting endeavors have not been systematically evaluated in terms of the relative amount of diversity they provide for analysis. The present study aimed to enhance the success of bioprospecting efforts by increasing the diversity while removing the genotypic redundancy often present in large collections of bacteria. We developed a multivariate sampling and marker-based selection strategy that significantly increase the diversity of bacteria recovered from plants. In doing so, we quantified the effects of varying sampling intensity, media composition, incubation conditions, plant species, and soil source on the diversity of recovered isolates. Subsequent sequencing and high-throughput phenotypic analyses of a small fraction of the collected isolates revealed that this approach led to the recovery of over a dozen rare and, to date, poorly characterized genera of plant-associated bacteria with significant biopesticide activities. Overall, the sampling and selection approach described led to an approximately 5-fold improvement in efficiency and the recovery of several novel strains of bacteria with significant biopesticide potential.

Design of a Delayed Dual-Core Lock-Step Processor with Automatic Recovery in Soft Errors (소프트 에러 발생 시 자동 복구하는 이중 코어 지연 락스텝 프로세서의 설계)

  • Juho Kim;Seonghyun Yang;Seongsoo Lee
    • Journal of IKEEE
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    • v.27 no.4
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    • pp.683-686
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    • 2023
  • In this paper, we designed a Delayed Dual Core Lock-Step (D-DCLS) processor where two cores operate same instructions with delay and the result is compared to mitigate soft errors and common mode failures in automotive electronic systems. Because D-DCLS does not know which core an error occurred in, each core must be recovered to the point before the error occurred, but complex hardware modifications are required to return all intermediate values on the pipeline stage. In this paper, in order for easy hardware implementation, all register values are saved to a buffer whenever a branch instruction is executed. When an error is detected, the saved register values are automatically restored, and then 'BX LR' instruction is executed to return to the last branch point. The proposed D-DCLS processor was designed using Verilog HDL and was confirmed to continue normal operation after automatically recovering error.

An Out of Core Linear Direct Solution Method for Large Scale Structural Analysis (대규모 구조해석을 위한 보조기억장치 활용 선형 직접해법)

  • Kim, Min-Ki;Kim, Seung Jo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.6
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    • pp.445-452
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    • 2014
  • This paper discusses the multifrontal direct solution method with out of core storage for large scale structural analysis in a limited computing resource. Large scale structural analysis requires huge amount of memory space and computation, so out of core solution method is needed in limited computing resource. In this research, out of core multifrontal solution algorithm which utilize the small size of physical memory and minimize the amount of access of low speed out of core storage is introduced. Three ideas, which are stack space in lower trianglar part of square factorization matrix, inverse stack data structure and selective data caching and recovery by data block size, are proposed.

Production and Remanufacturing Planning under Uncertain Supply of Recovery Cores and a Disassemble-to-order Environment (재생품 공급량이 불확실한 주문시분해 환경에서의 생산 및 재제조 계획)

  • Kang, Changmuk
    • Journal of the Korean Operations Research and Management Science Society
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    • v.38 no.2
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    • pp.43-63
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    • 2013
  • Remanufacturing is a process of recovering end-of-life products into serviceable parts for producing new products. Due to the limited supply of recovery cores to remanufacture, a remanufacturing firm also needs to produce or procure new parts for fulfilling the demand. This paper is targeted for solving the problem of determining the optimal amount of newly produced and remanufacturing parts, which is called production and remanufacturing planning (PRP) problem, under uncertain supply of recovery cores. The new production mitigates the risk of insufficient core supply while it takes more costs than the remanufacturing. The PRP model in this paper also considers disassemble-to-order (DTO) environment, in which multiple kinds of parts are remanufactured from multiple products on order of the parts. Whereas existing studies presents only heuristic solutions for DTO remanufacturing, this paper provides an exact solution for this problem and analytical sensitivity of the involved cost parameters, adopting multi-dimensional newsvendor modeling and stochastic linear programming techniques. The result shows that production and remanufacturing plans for multiple products are mutually dependent, and a change of cost parameters involved in only one part is propagated to all other parts.

Effect of treatment temperature on mechanical properties of silk textiles made with silk/polyurethane core-spun yarn

  • Bae, Yeon Su;Um, In Chul
    • International Journal of Industrial Entomology and Biomaterials
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    • v.33 no.2
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    • pp.108-112
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    • 2016
  • Silk has been used extensively in textile applications because of its good luster and feel. However, the low elongation and elastic recovery of silk has limited its use in a wider variety of textile applications. In this study, silk textile samples were made with a highly twisted silk/polyurethane core-spun yarn. They were immersed in water and dried at different temperatures, and the effect of treatment temperature on the mechanical properties of the silk textile was examined. It was found that the water temperature strongly affected the morphology and mechanical properties of the silk textile, whereas the drying temperature did not. As the water temperature was increased, the weft silk yarn became tangled and the interval between warp yarns decreased, resulting in shrinkage of the silk textile. When the silk textile was immersed in water at high temperature (i.e., $100^{\circ}C$), the elongation of the textile increased eight-fold as compared to an untreated silk textile. The maximum elastic recovery ratio of the silk textile was 96.7%.

The Recovery Process of Alcohol Dependent Men Living in a Therapeutic Community (치료공동체에 거주하는 남성 알코올의존자의 회복과정)

  • Kang, Sungye
    • Journal of Korean Academy of Nursing
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    • v.47 no.2
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    • pp.267-276
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    • 2017
  • Purpose: The purpose of this study was to explore the recovering process of men who had abused alcohol and has lived in a therapeutic community. Methods: Individual in-depth interviews were used to collect data from 10 of these men who has lived in the therapeutic community for more than one year. Qualitative data from field notes and transcribed notes were analyzed using the grounded theory methodology developed by Strauss and Corbin. Results: The core category about the recovering process of the men who had abused alcohol and are now in the therapeutic community was identified as "reconstructing a broken life". The recovering process of these men in the therapeutic community consisted of four phases; 'self-awareness stage', 'unfreezing stage', 'readjustment stage', and 'challenging stage'. Conclusion: In this study "reconstructing a broken life", as the core category vividly showed joys and sorrows of men who had abused alcohol and has lived in the recovering process of managing the yoke of life-long disease. In this process of recovery from alcoholic dependence the men gradually adjusted themselves to their given condition. Also they gained coping strategies to care for, and protect themselves. Therefore health care providers can establish supportive programs in the clinical field to empower these men by reflecting their proactive coping strategies.