• 제목/요약/키워드: Critical Condition

검색결과 2,020건 처리시간 0.028초

김밥 조리조건에 따른 미생물 품질 평가와 중요관리점의 관찰 (Microbiological Quality Assessment of Kimbap According to Preparation and Cooking Condition and Identification of Critical Control Points in the Processes)

  • 김종규
    • 한국식품위생안전성학회지
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    • 제19권2호
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    • pp.66-73
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    • 2004
  • 본 연구에서는 보통의 조리조건과 위생적 조리조건에서 김밥을 조리하였을 때에, 각 조리조건하에서의 식자재(원재료),조리자의 손, 조리환경(조리기구 및 조리실),그리고 완성된 김밥의 미생물 품질을 살펴보고 이를 토대로 김밥조리과정 중의 중요관리점(CCPs)을 관찰하였다. 김밥과 그 원재료,조리자의 손, 그리고 조리기구(칼, 도마 및 김발)의 표준평판균, 대장균군, 분변성대장균군, 대장균, 황색포도상구균, 살모넬라균 등의 미생물을 식품공전에 준하여 측정하였으며 조리실의 미생물 오염도를 평가하였다. 모든 시료에서 대장균, 황색포도상구균 및 살모넬라균은 검출되지 않았으며 표준평판균, 대장균군 및 분변성대장균군은 보통의 조리조건에서보다 위생적 조건에서 현저하게 낮았다 김밥 원재료 중 비가열재료에서는 가열재료보다 표준평판균 및 대장균군수가 많이 검출되었다. 두 조건에서 조리실의 공중낙하균은 모두 양호한 수준이었다. 위생적 조리조건에서 만든 김밥은 보통의 조리조건에서 만든 김밥 에 비하여 표준평판균과 대장균군이 1/100수준이었으나 아직 분변성대장균군이 검출되었다. 따라서 비가열재료, 조리기구 및 조리자의 손의 미생물 오염, 그리고 조리 중의 교차오염이 김밥 미생물 오염의 주요 근원으로 지적되며, 비가열재료의 취급, 조리기구의 세척과 소독 및 조리자의 손씻기 단계가 CCPs로 제시된다.

고온단속변형량이 단상 Cu-Zn합금의 정적연화에 미치는 영향 (Effect of Hot Interrupted strain on Static Softening of Single Phase Cu-Zn Alloy)

  • 권용환;조상현;유연철
    • 소성∙가공
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    • 제4권2호
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    • pp.169-179
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    • 1995
  • Static restoration mechanism during hot interrupted deformation of Cu-Zn alloy was studied in the temperature range from $550^{\circ}C$ to $750^{\circ}C$ and at a constant strain rate of 0.1/sec. At a given temperature, the hot interrupted deformations were performed with variation of interrupted time $t_i$ form 1 to 50 sec and of interrupted strain ${\varepsilon}_i$ from 0.15 to 0.90. From the analysis of the values of the critical strain of ${\varepsilon}_c$ for tje initiation of dynamic recrystallization and the peak strain of${\varepsilon}_p$, the relationship ${\varepsilon}_c{\fallingdotseq}0.7{\varepsilon}_p$ was obtained. It was clarified that the softening of the interrupted deformation was mainly the static recrystallization and the fractional softening(FS) which was over 30% mostly confirmed this result. The fractional softening of the interrupted time $t_i$ especially and pre-strain. The FS increased with increasing strain rate, interrupted time and pre-strain. The change of microstructures after hot deformation could be predicted by the FS. when the FS was 30~100%, static recrystallization was happened and grain growth was observed at the condition which was $750^{\circ}C$ deformation temperature, 0.45 prestrain and this condition's FS value was over 100%.

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신체장애인의 주거환경 개조에 관한 연구 - 인천시 주거개조 사례 27개를 중심으로 - (A Study on the Remodeling of Living Research about living environment renovation for disabled - Based on 27 cases of residence renovation in Incheon city -)

  • 조철호;소준영
    • 한국실내디자인학회논문집
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    • 제19권2호
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    • pp.234-242
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    • 2010
  • The twenty seven houses at Incheon city, were remodeled in 2009 for the physically handicapped people. This research had been done the analysis of the itemized questionnaire by the needs of the physically handicapped for their better living environment and suggested the following remodeling devices. First of all, there was the priority for the remodeling of their living facilities. According to their priority, they wanted to remodel their bathroom, kitchen & dining room, veranda, living room, and hall way. These were based on their needs of movement, personal hygiene, convenient closet, and cabinet usage. In particular, their demands were shown as followings. The wheelchair using handicapped people required safe doorknobs, unslippery floor materials, removal of step levels, and heights adjustable washing stand for their bathroom. They also requested washboard, non-threshold, and automatic door locks. Otherwise, the disabled in critical condition who could not move anything preferred the remodeling of inner structure of living spaces and automatic door system. The slight disabled and the families those who have the disabled demanded the remodeling of kitchen & dining room, and preferred the reorganization of closet, cabinets, floor tiles, and turncock. The remodeling of bedroom was mostly requested by the disabled women, people with the brain disorder, and disabled people in critical condition who could not move anything. They wanted the remote controlled lightings.

On the Stability of Critical Point for Positive Systems and Its Applications to Biological Systems

  • Lee, Joo-Won;Jo, Nam Hoon;Shim, Hyungbo;Son, Young Ik
    • Journal of Electrical Engineering and Technology
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    • 제8권6호
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    • pp.1530-1541
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    • 2013
  • The coexistence and extinction of species are important concepts for biological systems and can be distinguished by an investigation of stability. When determining local stability of nonlinear systems, Lyapunov indirect method based on the Jacobian linearization has been widely employed due to its simplicity. Despite such popularity, it is not applicable to singular systems whose Jacobian has at least one eigenvalue that is equal to zero. In such singular cases, an appropriate Lyapunov function should be sought to determine the stability of systems, which is rather difficult and quite involved. In this paper, we seek for a simple criterion to determine stability of the equilibrium that is located at the boundary of the positive orthant, when one of eigenvalues of the Jacobian is zero. The goal of the paper is to present a generalized condition for the equilibrium to attract all trajectories that starting from initial condition in the positive orthant and near the equilibrium. Unlike the Lyapunov direct method, the proposed method requires just a simple algebraic computation for checking the stability of the critical point. Our approach is applied to various biological systems to show the effectiveness of the proposed method.

CF8M 주조 스테인리스강의 2축 피로수명 예측을 위한 파라미터의 제안 (A Proposal of Parameter to Predict Biaxial Fatigue Life for CF8M Cast Stainless Steels)

  • 박중철;권재도
    • 대한기계학회논문집A
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    • 제29권6호
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    • pp.815-821
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    • 2005
  • Biaxial low cycle fatigue test was carried out to predict fatigue life under combined axial-torsional-loading condition which is that of in-phase and out-of-phase for CF8M cast stainless steels. Fatemi-Socie(FS) parameter which is based on critical plane approach is not only one of methods but also the best method that can predict fatigue life under biaxial loading condition. But the result showed that, biaxial fatigue life prediction by using FS parameter with several different parameters for the CF8M cast stainless steels is not conservative but best results. So in this present research, we proposed new fatigue life prediction parameter considering effective shear stress instead of FS parameter which considers the maximum normal stress acting on maximum shear strain and its effectiveness was verified.

Dynamic deflection monitoring of high-speed railway bridges with the optimal inclinometer sensor placement

  • Li, Shunlong;Wang, Xin;Liu, Hongzhan;Zhuo, Yi;Su, Wei;Di, Hao
    • Smart Structures and Systems
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    • 제26권5호
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    • pp.591-603
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    • 2020
  • Dynamic deflection monitoring is an essential and critical part of structural health monitoring for high-speed railway bridges. Two critical problems need to be addressed when using inclinometer sensors for such applications. These include constructing a general representation model of inclination-deflection and addressing the ill-posed inverse problem to obtain the accurate dynamic deflection. This paper provides a dynamic deflection monitoring method with the placement of optimal inclinometer sensors for high-speed railway bridges. The deflection shapes are reconstructed using the inclination-deflection transformation model based on the differential relationship between the inclination and displacement mode shape matrix. The proposed optimal sensor configuration can be used to select inclination-deflection transformation models that meet the required accuracy and stability from all possible sensor locations. In this study, the condition number and information entropy are employed to measure the ill-condition of the selected mode shape matrix and evaluate the prediction performance of different sensor configurations. The particle swarm optimization algorithm, genetic algorithm, and artificial fish swarm algorithm are used to optimize the sensor position placement. Numerical simulation and experimental validation results of a 5-span high-speed railway bridge show that the reconstructed deflection shapes agree well with those of the real bridge.

에어제트직기 주 노즐내 천음속 유동의 수치 해석적 연구 (A Numerical Analysis of Transonic Flows in an Axisymmetric Main Nozzle of Air-Jet Loom)

  • 오태훈;김상덕;송동주
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 1998년도 춘계 학술대회논문집
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    • pp.168-173
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    • 1998
  • A numerical analysis of axisymetric backward facing step main nozzle flow in air jet loom has been accomplished. To obtain basic design data for an optimum main nozzle for an air-jet loom and to predict the transonic/supersonic flow, a characteristic based upwind flux difference splitting compressible Navier-Stokes method has been used. The wall static pressure of the main nozzle and the flow velocity changes in the nozzle tube were analyzed by changing air tank pressures and acceleration tube lengths. The flow inside the nozzle experiences double choking one at the needle tip and the other at the acceleration tube exit at tank pressures over $4kg_f/cm^2$. The tank pressure $P_t$ leading to the critical condition depends on the acceleration tube length; i.e, $P_t$ is higher for longer acceleration tubes. The $P_t$ value required to bring the acceleration tube exit to the critical condition is nearly constant regardless of acceleration tube length. The round needle tip shape might lead to less total pressure loss when compared with step shape.

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분포접선력을 받는 탄성지지된 보의 동적 불안정 (Dynamic Instability of Elastically Restrained Beams under Distributed Tangential Forces)

  • 류봉조;김인우;이규섭;임경빈;최봉문
    • 한국정밀공학회지
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    • 제15권10호
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    • pp.140-147
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    • 1998
  • The dynamic behavior of elastically restrained beams under the action of distributed tangential forces is investigated in this paper. The beam, which is fixed at one end, is assumed to rest on an intermediate spring support. The governing equations of motion are derived from the energy expressions, and the finite element formulation is employed to calculate the critical distributed tangential force. Jump phenomena for the critical distributed tangential force and instability types are presented for various spring stiffnesses and support positions. Stability maps are generated by performing parametric studies to show how the distributed tangential forces affect the frequencies and the stability of the system considered. Through the numerical simulations, the following conclusioils are obtained: (i) Only flutter type instability exists for the dimensionless spring stiffness K $\leq$ 97, regardless of the position of the spring support. (ii) For the dimensionless spring stiffness K $\leq$ 98, the transition from flutter to divergence occurs at a certain position of the spring support, and the transition position moves from the free end to the free end of the beam as the spring stiffness increases. (iii) For K $\leq$ 10$^{6}$ the support condition can be regarded as a rigid support condition.

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고객만족교육에서 서비스몰입에 영향을 미치는 요인에 관한 연구: 금융기관 종사자를 중심으로 (A Study on the Factor Affecting the Service Commitment in Customer Satisfaction Education: Focused on Financial Institute Employee)

  • 배인정;박소은;최정일
    • 품질경영학회지
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    • 제44권1호
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    • pp.121-138
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    • 2016
  • Purpose: Financial institute employees have various education programs for enhancing customer satisfaction. The purpose of this study is to explore critical factors that affect the service commitment in the financial institution and to propose the implication for employee's service involvement. Methods: This study is intended to identify how service quality of education, servicescape, and learning motivation affect the service commitment. The research model proposed in this study is tested via a survey of 322 employees for financial institution employees. Results: This study shows that tangibles, reliability, assurance and ambient condition, physical structure, symbolic artifacts and internal motivation, extrinsic motivation significantly influence education satisfaction. Tangibles, reliability and ambient condition, physical structure, symbolic artifacts and internal motivation significantly influence affective service orientation and that tangibles, reliability, assurance and extrinsic motivation significantly influence altruistic service orientation. It also verifies that education satisfaction affective service orientation, and altruistic service orientation positively affect service commitment. Conclusion: This study suggests critical factors to promote service commitment in the financial institute. It has focused on not only the service quality of education program, but also servicescape and learning motivation as the meaningful factors for increasing the employee's service involvement.

축하중을 고려한 마이크로파일의 임계좌굴특성 (Critical Buckling Characteristics of Micropiles Under Axial Loads)

  • 정현식;노인수;이영생
    • 한국지반공학회논문집
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    • 제31권9호
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    • pp.39-51
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    • 2015
  • 근래 구조물 기초보강을 위한 마이크로파일공법의 적용사례가 점차 증가하고 있으며, 이에 따른 관련 연구가 다수 수행되고 있다. 그러나 국내 연구는 대부분 Case. I, II-Type의 지지거동에 국한되어 마이크로파일 자체의 구조적 검토에 대한 연구는 미미한 실정이다. 따라서 본 논문에서는 국내에서 주로 사용되는 마이크로 파일에 대한 각각의 강봉 및 그라우트조건에 따른 좌굴특성을 검토하였다. 검토결과 마이크로파일 직경이 작을수록 지반의 임계좌굴점착력($C_{ucr}$)는 증가하게 되며, 특히 임계좌굴길이($L_{cr}$) 이하에서는 마이크로파일 길이가 길수록 임계좌굴하중($P_{cr}$)이 감소함을 알 수 있었다. 또한 축하중을 받는 마이크로파일의 좌굴파괴와 압축파괴 가능성을 구분, 평가할 수 있는 방법을 제시하였다.