• Title/Summary/Keyword: Critical control point

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Tunnel Safety Assessment by using the Concept of the Critical Strain in the Ground (한계변형률 개념을 활용한 터널안전성 평가)

  • Park, Si-Hyun;Park, Sung-Kun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.571-576
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    • 2010
  • In this study, an application method of critical strains concept for tunnels' safety by using the values of measured displacements which are obtained in the field is discussed. The aim is to: (1) study on the engineering meanings of critical strains concept by reviewing the previous researches and application examples with measured displacement values; (2) study on the engineering reasonability of critical strains concept with the view point of a tunnel engineering and a geotechnical engineering; (3) study on the features of ground deformation due to tunneling and reciprocal relation between total displacement and measured displacement; (4) evaluate a tunnel safety by using domestic measurements collected in the field; and (5) re-evaluate the control criteria which were previously used in the field, with the view point of critical strains concept. Consequently, it was confirmed that critical strains in the ground has a reasonability and a possibility of unified or common concept with the view point of a tunnel engineering.

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A study on establishment of bio-hazard analysis and critical control point for pork slaughter house (돼지도축장의 생물학적 위해요소에 대한 중요관리점 설정)

  • 옥천석;정지영;송은아;이성식
    • Korean Journal of Veterinary Service
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    • v.24 no.2
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    • pp.117-126
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    • 2001
  • To ensure the safety of domestic livestock products, the government made it obligatory to enforce the hazard analysis critical control point(HACCP) in all domestic slaughterhouses. Under the HACCP, most of the hazards generated in slaughterhouses are bio-hazards, especially pathogenic bacteria. In order to reduce to the pathogenic bacteria, critical control point (CCP) is established and controled in the process of slaughter. A study was carried out to measure the level of bacterial contamination of swine carcass in 6 slaughterhouses selected. As a result, the aerobic plate counts(cfu/$\textrm{cm}^2$) of all samples was $10^2$-10 in average, except slaughterhouse C. The level of the aerobic plate counts on the surface of lower loin in slaughterhouse C was $10^4$ and it was considered that slaughterhouse C should set the process of manual transport of carcass as the CCP. Escherichia coli level was the highest in middle line cut surface. Especially, E coli level of slaughterhouses C and D were about 6.5- and 3.0-fold higher than that of other 4 slaughterhouses. Thus, it was considered that the slaughterhouses C and D should set the process of the entrails treatment as the CCP. The air contamination was measured at two point in a slaughterhouse. The air contamination level was 4-13 times higher than that of the standard Japanese slaughterhouses.

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Development of an Hazard Analysis Critical Control Point (HACCP) Application Model for Dried Anchovy Workplace (마른멸치 작업장의 식품안전관리인증기준(HACCP)모델 개발)

  • YOON, Hyun-Jin;HAM, In-Tae;Kim, Sang-Hyeon;CHOI, Jong-Duck
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.3
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    • pp.713-726
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    • 2016
  • This study were attempted to apply the HACCP system adopted in the dried anchovy workplace to ensure the hygiene safety of dried anchovy workplace. In this study, HACCP system procedures, including HACCP team organization, determination of critical control point(CCP), establishment of critical limits, mornitering and verification etc., were established using KFDA 12 procedures. To determine whether hazards were critical elements, we evaluated the likelihood and seriousness of each hazard element. The likelihood of residual microorganism and metal piece exceeding the acceptable limit in dried anchovy products were demonstrated to be a critical hazard element. Management of the boiling(CCP-1B) and metal detection(CCP-2P) were determined to be a critical control point. The standards for acceptable residual microorganism and metal piece were set based on relevant laws and regulations, and then the limits were adapted and established for the CCP. An HACCP plan applicable to dried anchovy workplace was established.

Biological and Chemical Hazards Factor Analysis for CCP(Critical Control Point) in Fried Process of Fried Noodles (유탕면류의 유탕공정 중 중요관리점(CCP)을 위한 미생물학적, 화학적 위해요소분석)

  • Kwon, Sang-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.8
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    • pp.3578-3585
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    • 2012
  • The purpose of this study was to establish the critical limit at CCP (Critical Control Point) of HACCP (Hazard Analysis Critical Control Point) system for instant noodle and it was conducted at P company in Ichen(Gyeonggi-do), Korea. According to the CCP, Fried process were experimented to removal and decrease of microbiological and chemical hazards by measuring of each temperature and times. As a result, the standard plate count and pathogenic microorganism were not detected by fried processing (Temperature : $145{\pm}10^{\circ}C$, Time : $75{\pm}30$ sec). The acid value of chemical hazards produced by fried processing was able to manage, showed lower (0.2) than the legal limit (0.6). Air-borne bacterial examination results detected(3 CFU/mL, 3 CFU/mL) in the Frying Room and Steam Room. Therefore, the CCP-BC of fried process would be a great alternative to prevent and remove hazard analysis, such as general and pathogenic microorganism (E. coli O157:H7, B. cereus, Listeria monocytogenes, Salmonella spp, Sthaph. aureus etc), chemical hazard analysis. In conclusion, it suggested that HACCP plan was necessary for management standard and systematic approach in establishement of critical limit, solving the problem, method of verification, education and records management by fried processing.

Unit Response Optimizer mode Design of Ultra Super Critical Coal-Fired Power Plant based on Fuzzy logic & Model Predictive Controller (퍼지 로직 및 모델 예측 제어기 적용을 통한 초초임계압 화력발전소 부하 응답 최적화 운전 방법 설계)

  • Oh, Ki-Yong;Kim, Ho-Yol
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.12
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    • pp.2285-2290
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    • 2008
  • Even though efficiency of coal-fired power plant is proportional to operating temperature, increasement of operating temperature is limited by a technological level of each power plant component. It is an alternative plan to increase operating pressure up to ultra super critical point for efficiency enhancement. It is difficult to control process of power plant in ultra super critical point because that point has highly nonlinear characteristics. In this paper, new control logic, Unit Response Optimizer Controller(URO Controller) which is based on Fuzzy logic and Model Predictive Controller, is introduced for better performance. Then its performance is tested and analyzed with design guideline.

A study on the food clean room system observing the regulations of HACCP (HACCP의 환경 최적화를 위한 식품 클린룸 설계에 관한 연구)

  • Won, Young-Jae;Suh, Kee-Won
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.520-526
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    • 2009
  • This study proposed the optimum design values for the biological clean room system observing the regulations of Hazard Analysis Critical Control Point (HACCP). Even though the standard for industrial clean room system has been well established, the basis for biological food clean room system is the first stage. In order to prevent the contaminations in advance for food storages, processes, and distributions, the criterion of Hazard Analysis Critical Control Point is positively required. This study also suggested the possible ways of how to avoid the hazardous contaminations.

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HACCP의 환경 최적화를 위한 식품 클린룸 설계에 관한 연구

  • Won, Yeong-Jae
    • Air Cleaning Technology
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    • v.23 no.3
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    • pp.1-9
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    • 2010
  • This study proposed the optimum design values for the biological clean room system observing the regulations of Hazard Analysis Critical Control Point (HACCP). Even though the standard for industrial clean room system has been well established, the basis for biological food clean room system is the first stage. In order to prevent the contaminations in advance for food storages, processes, and distributions, the criterion of Hazard Analysis Critical Control Point is positively required. This study also suggested the possible ways of how to avoid the hazardous contaminations.

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Localized Algorithm to Improve Connectivity and Topological Resilience of Multi-hop Wireless Networks

  • Kim, Tae-Hoon;Tipper, David;Krishnamurthy, Prashant
    • Journal of information and communication convergence engineering
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    • v.11 no.2
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    • pp.69-81
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    • 2013
  • Maintaining connectivity is essential in multi-hop wireless networks since the network topology cannot be pre-determined due to mobility and environmental effects. To maintain the connectivity, a critical point in the network topology should be identified where the critical point is the link or node that partitions the network when it fails. In this paper, we propose a new critical point identification algorithm and also present numerical results that compare the critical points of the network and H-hop sub-network illustrating how effectively sub-network information can detect the network-wide critical points. Then, we propose two localized topological control resilient schemes that can be applied to both global and local H-hop sub-network critical points to improve the network connectivity and the network resilience. Numerical studies to evaluate the proposed schemes under node and link failure network conditions show that our proposed resilient schemes increase the probability of the network being connected in variety of link and node failure conditions.

Modified method for auto-tuning of PID controller using relay feedback (릴레이 피드백을 이용한 개선된 PID 제어기 자동동조 기법)

  • 신창훈;윤명현;정학영
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1004-1007
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    • 1996
  • Various auto-tuning methods using relay feedback are presented recently. They are composed of the consecutive procedures identifying Nyquist critical point using relay feedback and designing PID controller by one point of Nyquist plot mapping. This paper suggests a strategy to get the knowledges of Nyquist critical point and the neighborhood point of it using relay feedback. The parameters of PID controller are established by dominant pole approximation based on these knowledges. Designers can make use of the damping ratio as a time domain specification. So design flexibilities are taken in view of stability and performance of the system response considering practical system condition.

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Consideration to the Stability of FLC using The Circle Criterion (Circle Criterion을 이용한 FLC의 안정도에 대한 고찰)

  • Lee, Kyoung-Woong;Choi, Han-Soo
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.5
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    • pp.525-529
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    • 2009
  • Most of FLC received input data from error e and change-of-error e' with no relation with system complexity. Basic scheme follows typical PD and PI or PID Controller and that has been developed through fixed ME In this paper, We studied the relationship between MF and system response and system response through changing Fuzzy variable of consequence MF and propose the simple FLC using this relationship. The response of FLC is changed according to the width of Fuzzy variable of consequence MF. As changing the Fuzzy variable of consequence MF shows various nonlinear characteristic, we studied the relation between response and MF using analytical method. We designed the effective FLC using three-variable MF and nine rules and took simulation for verification. In this study, we propose the method to design system with FLC in stability point which is an impotent characteristic of designing system. The circle criterion which is adapted to analysis the nonlinear system is put to use for proposed method. Since SISO FLC has a time-invariant and odd characteristic we can use the critical point not disk which is generally used to determine the stability in the circle criterion, to determine the stability. Using this, we can get the maximum critical point plot of SISO FLC with changing the consequence fuzzy variables. The predetermined critical point plot of FLC can be used to decide the region of the system to be stable. This method is effectively used to design the SISO FLC.