• Title/Summary/Keyword: I-T curve

검색결과 245건 처리시간 0.037초

Detection of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp. and Staphylococcus aureus using duplex real-time PCR assay with melting curve analysis on fresh lettuce

  • Lee, Na-Ri;Kwon, Kyung-Yoon;Choi, Sung-Wook;Koo, Min-Seon;Chun, Hyang-Sook
    • Journal of Food Hygiene and Safety
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    • 제26권2호
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    • pp.114-119
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    • 2011
  • In this study, two duplex real-time PCR approach with melting curve analysis is presented for the detection of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp. and Staphylococcus aureus, which are important food-borne bacterial pathogens usually present in fresh and/or minimally processed vegetables. Reaction conditions were adjusted for the simultaneous amplification and detection of specific fragments in the ${\beta}$-glucuronidase (uidA, E. coli), thermonuclease (nuc, S. aureus), hemolycin (hly, L. monocytogenes) and tetrathionate reductase (ttr, Salmonella spp.) genes. Melting curve analysis using a SYBR Green I real-time PCR approach showed characteristic $T_m$ values demonstrating the specific and efficient amplification of the four pathogens; $80.6{\pm}0.9^{\circ}C$, $86.9{\pm}0.5^{\circ}C$, $80.4{\pm}0.6^{\circ}C$ and $88.1{\pm}0.11^{\circ}C$ for S. aureus, E. coli O157:H7, L. monocytogenes and Salmonella spp., respectively. For all the pathogens, the two duplex, real-time PCR was equally sensitive to uniplex real-time PCR, using same amounts of purified DNA, and allowed detection of 10 genome equivalents. When our established duplex real-time PCR assay was applied to artificially inoculated fresh lettuce, the detection limit was $10^3$ CFU/g for each of these pathogens without enrichment. The results from this study showed that the developed duplex real-time PCR with melting curve analysis is promising as a rapid and cost-effective test method for improving food safety.

Measure and Assessment of Process Capability for Nonnormal Process Data (비정규 공정 데이터에 대한 공정능력의 측도 및 평가)

  • Kim, Hong-Jun;Song, Suh-Ill
    • Proceedings of the Korean Society for Quality Management Conference
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    • 한국품질경영학회 1998년도 The 12th Asia Quality Management Symposium* Total Quality Management for Restoring Competitiveness
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    • pp.594-609
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    • 1998
  • In this dissertation, a new process capability index $C_{psk}$ is introduced for non-normal process. The Pearson curve and the Johnson curve are selected for capability index calculation and data modeling the normal-based index $C_{psk}$ is used as the model for non-normal process. A significant result of this research find that the ranking of the seven indices, $C_p,\;C_{pk},\;C_{pm},\;C^{\ast}_{pm},\;C_{pmk},\;C_s,\;C_{psk}$ in terms of sensitivity to departure of the process median from the target value T=M from the most sensitive one up to the least sensitive are $C_{psk},\;C_{s},\;C_{pmk},\;C^{\ast}_{pm},\;C_{pm},\;C_{pk},\;C_p$. i.e, By the criteria adopted for evaluation of PCI's $C_{psk}$ is the most sensitive to the departure of the process median from target and $C_p$ is least

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Pencil Curve Computation for Clean-up Machining (잔삭 가공을 위한 펜슬커브 생성)

  • Park T.J.;Park S.C.
    • Korean Journal of Computational Design and Engineering
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    • 제11권1호
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    • pp.20-26
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    • 2006
  • This paper presents a procedure to compute pencil curves from a triangular mesh which is offset with the radius of a given ball-end mill. An offset triangular mesh has numerous self-intersections caused by an abundance of invalid triangles, which do not contribute to the valid CL-surface. Conceptually, we can obtain valid pencil curves by combining all intersections tying on the outer skin of the offset triangular mesh, i.e., the valid CL-surface. The underlying concept of the proposed algorithm is that visible intersections are always valid for pencil curves, because visible intersections lie on the outer skin of the offset model. To obtain the visibility of intersections efficiently, the proposed algorithm uses a graphics board, which performs hidden surface removal on up to a million polygons per second.

A study on a modeling method about current-voltage characteristic of HTS tape considering resistance of stabilizer

  • Lee, W.S.;Lee, J.;Nam, S.;Ko, T.K.
    • Progress in Superconductivity and Cryogenics
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    • 제15권3호
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    • pp.9-12
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    • 2013
  • Current-voltage characteristic models of superconducting material are suggested by many researchers. These current-voltage characteristic models are important because they can be used for design or simulation of superconductor devices. But widely used current-voltage models of superconductor wire still have some limitations. For example, a standard E-J power model has no parameters related with stabilizer's resistance in superconductor wire. In this paper, a current-voltage characteristic modeling method for high temperature superconductor (HTS) tape with considering the effect of stabilizer is introduced. And a current-voltage characteristic of a HTS tape is measured under different stabilizer conditions. Those measured current-voltage characteristics of the HTS tape modeled with proposed modeling method and the modeling results are compared.

Evaluation of Material Properties due to Thermal Embrittlement in CF8M Cast Austenitic Stainless Steel (CF8M 주조 오스테나이트 스테인리스강의 열취화에 따른 재료물성치 평가)

  • Kim, C.;Park, H.B.;Jin, T.E.;Jeong, I.S.;Seok, C.S.;Park, J.S.
    • Proceedings of the KSME Conference
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.131-136
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    • 2003
  • CF8M cast austenitic stainless steel is used for several components such as primary coolant piping, elbow, pump casing, and valve bodies in light water reactors. These components are subject to thermal aging at the reactor operating temperature. Thermal aging results in spinodal decomposition of the delta-ferrite leading to increased strength and decreased toughness. In this study, three kinds of the aged CF8M specimen were prepared using an artificially simulated aging method. The objective of this study is to summarize the method of estimating ferrite contents, Charpy impact energy and J-R curve, and to evaluate the thermal embrittlement of the CF8M cast austenitic stainless steel piping used in the domestic nuclear power plants.

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Inrush Current Detection of Power Transformer using Flux-current Derivative Curve (자속-전류비율곡선을 이용한 전력용 변압기의 여자돌입검출)

  • Kim, S.K.;Park, C.W.;Shin, M.C.;Suh, H.S.;Jang, B.T.;Kim, I.D.;Kim, Y.H.
    • Proceedings of the KIEE Conference
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    • 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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    • pp.186-189
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    • 1996
  • Convential inrush current detection method is used to harmonic restraint method by filtered second frequency component. Nowadays this technique must be modified because harmonics are occurred in steady state of power system. A purpose of this study is to develop of inrush current detection relaying algorithm for power transformer based on flux-current derivative curve method. We used the relaying signals obtained from EMTP simulation.

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MYLLER CONFIGURATIONS IN FINSLER SPACES. APPLICATIONS TO THE STUDY OF SUBSPACES AND OF TORSE FORMING VECTOR FIELDS

  • Constantinescu, Oana
    • Journal of the Korean Mathematical Society
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    • 제45권5호
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    • pp.1443-1482
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    • 2008
  • In this paper we define a Myller configuration in a Finsler space and use some special configurations to obtain results about Finsler subspaces. Let $F^{n}$ = (M,F) be a Finsler space, with M a real, differentiable manifold of dimension n. Using the pull back bundle $({\pi}^{*}TM,\tilde{\pi},\widetilde{TM})$ of the tangent bundle $(TM,{\pi},M)$ by the mapping $\tilde{\pi}={\pi}/TM$ and the Cartan Finsler connection of a Finsler space, we obtain an orthonormal frame of sections of ${\pi}^{*}TM$ along a regular curve in $\widetilde{TM}$ and a system of invariants, geometrically associated to the Myller configuration. The fundamental equations are written in a very simple form and we prove a fundamental theorem. Important lines in a Finsler subspace are defined like special lines in a Myller configuration, geometrically associated to the subspace: auto parallels, lines of curvature, asymptotes. Torse forming vector fields with respect to the Cartan Finsler connection are characterized by means of the invariants of the Frenet frame of a versor field along a curve, and the new notion of torse forming vector fields in the sense of Myller is introduced. The particular cases of concurrence and parallelism in the sense of Myller are completely studied, for vector fields from the distribution $T^m$ of the Myller configuration and also from the normal distribution $T^p$.

The Use of Semi-Adiabatic Calorimetry for Hydration Studies of Cement Paste

  • Chung, Chul-Woo;Kim, Ji-Hyun;Lee, Soo-Yong
    • Journal of the Korea Institute of Building Construction
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    • 제16권2호
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    • pp.185-192
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    • 2016
  • The semi-adiabatic calorimetry technique is a robust and easy technique that can be used to measure the temperature rise of concrete. This method is often used for investigating the maturity of concrete, as well as to predict maximum temperature rise of mass concrete using various heat loss compensating models. Semi-adiabatic calorimetry can also be used for predicting setting time of concrete. However, it has seldom been used to investigate the hydration characteristics of various cement paste samples. In this research, semi-adiabatic calorimetry and X-ray diffraction methods were used to investigate the hydration characteristics of 3 different ASTM type I Portland cements. First derivative of temperature rise (dT/dt) curve was used to isolate individual peaks. Based on the results of the experiments, a combination of dT/dt curve with XRD could be used to successfully identify hydration at a specific time period, showing its potential to be used as an alternative tool for hydration studies of cement-based materials.

Review of Clinical Cancer Research Methodology of Botanical Agents (한약 및 천연물의 항암 임상연구 방법론에 대한 고찰)

  • Oh, Hye Kyung;Lee, Jee Young;Ryu, Han Sung;Yoon, Seong Woo
    • Journal of Korean Traditional Oncology
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    • 제20권1호
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    • pp.11-21
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    • 2015
  • Objectives : The cancer incidence and cancer burden is increasing. In addition, the use of botanical agents in cancer care is increasing. This article aims to review a research strategy for botanical agents. Methods : The clinical studies of anticancer botanical agents and the papers about clinical research methodology of botanical agents were reviewed. Results : In phase I study, safety confirmation, optimal dose determination and drug interaction study are important. Most botanical agents have low toxicity and some have non-monotone dose response. Therefore, dose-response curve must be evaluated separately from the dose-toxicity curve to determine optimal dose. Although anticancer botanical agents can't shrink tumor size rapidly, they do extend survival. So, in phase II study, response should be evaluated by the survival. Conclusions : Clinical research of botanical agents in cancer is different from traditional methods and strategies. Considering the characteristics of botanical agents and experimental mechanism is necessary in conducting botanical based clinical trials.