• 제목/요약/키워드: analytical values

검색결과 1,432건 처리시간 0.03초

우리나라 작업환경 측정기관의 정도관리를 위한 기준값에 관한 연구 (An Evaluation of Reference Values Used for Quality Control of the Korean Industrial Hygiene Laboratory)

  • 전정화;백남원
    • 한국산업보건학회지
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    • 제4권1호
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    • pp.103-116
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    • 1994
  • This study was conducted to evaluate accuracy and precision of reference values used for quality control of the Korean industrial hygiene laboratory for three rounds. Factors affecting on accuracy and precision, including analytical procedures, were investigated. The results are summarized as follows. 1. Pooled relative standard deviation of reference values analyzed by reference laboratories was 2.01-5.91%, and that by both reference laboratories and participated laboratories was 3.18-6.63%. Better results were obtained when results of reference laboratories were employed. 2. Significant relationship was indicated between analytical precision and concentration of materials in samples. Variation increased by decreasing sample concentration. 3. Recoveries of lead and cadmium were about 98.6% and 99.8% respectively. There was a significant difference between lead values with and without recovery correction. 4. Organic solvent results corrected by desorption efficiency only and those corrected by Both internal standards and desorption efficiency were more accurate than those uncorrected. But, the latter was the best.

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수산물 소비에 대한 가치체계 분석과 시장세분화에 관한 연구 (A Study on the Seafood Consumer's Value Analysis and Market Segmentation)

  • 장춘봉;장영수
    • 수산경영론집
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    • 제42권2호
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    • pp.47-68
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    • 2011
  • Values are lasting beliefs that are at the center of human behavior and not be often changed. Different values make different behaviors, and similar values form similar behaviors. Consumers' values affect not only the cognitive process but also behaviors in a powerful and comprehensive way. There have been many studies regarding prediction of consumer patterns and identification, measurement methods of values. This is because if we can accurately measure the value system, it can be used in many areas of marketing such as market segmentation, new product development, and advertisement. In case of seafood, it is also necessary to make marketing strategies by segmenting consumers based on their value systems. The objectives of this study are as follows: First, it is to find out the connection process from the properties of seafood products that consumers consider important, to the benefits, and finally to the values they pursue by applying the means-end chain theory, using the Laddering method. Second, using a two-step cluster analysis, we aim to segment seafood markets based on consumers' values and investigate characteristics of segmented markets. Based on objectives, it is expected that this study would provide informations on seafood consumers and help to establish seafood marketing strategies for producers and distributors. Analytical results of the value system using a means-end chain theory indicated that there were seven complete links, that is, ladders among fresh seafood products. In case of processed seafood products, there were total 9 complete ladders. The empirical analytical results of market segmentation according to the values showed fresh seafood products were divided into three groups. In case of processed seafood products were segmented into two groups.

Development Rapid Analytical Methods for Inositol as a Trace Component by HPLC and LC-MS/MS in Infant Formula

  • Shin, Jin-Ho;Park, Jung-Min;Kim, Ha-Jung;Ahn, Jang-Hyuk;Kwak, Byung-Man;Kim, Jin-Man
    • 한국축산식품학회지
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    • 제35권4호
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    • pp.466-472
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    • 2015
  • A rapid and simple analytical method, using liquid chromatography tandem mass spectrometry (LC-MS/MS), was developed to detect myo-inositol (MI) in infant formulas. For protein removal: acid hydrolysis and lipid removal through organic solvent extraction. The operating conditions for instrumental analysis were determined based on previously reported analogous methods that used LC-MS/MS. Quantitative analysis was used for the detection limit test, infant formula recovery test, and standard reference material (SRM) 1849a to verify the validity of our LC-MS/MS analytical method, which was developed to quantify MI. For validation, the results of our method were compared with the results of quantitative analyses of certified values. The test results showed that the limit of detection was 0.05 mg/L, the limit of quantitation was 0.17 mg/L, and the method detection limit was 17 mg/kg. The recovery test exhibited a recovery between 98.07-98.43% and a relative standard deviation between 1.93-2.74%. Therefore, the result values were good. Additionally, SRM 1849a was measured to have an MI content of 401.84 mg/kg and recovery of 98.25%, which is comparable to the median certified value of 409 mg/kg. From the aforementioned results, we judged that the instrumental analysis conditions and preparation method used in this study were valid. The rapid analytical method developed herein could be implemented in many laboratories that seek to save time and labor.

축대칭 중공실린더의 길이방향 온도분포하의 열탄성응력 해석에 관한 연구 (A Study on the Thermal Stress Analysis of Axi-Symmetric Hollow Cylinder)

  • 이상진;조진
    • 대한기계학회논문집A
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    • 제20권10호
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    • pp.3152-3159
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    • 1996
  • Previous works about the cylindrical shape elastic body which is under longitudinal temperature distribution mostly show the results of free expansion, therefore exact thermo-elastic analysis is needed. The object of this work is to analyze the thermo-elastic problem of the hollow cylinder when the cylinder is under longitudinal temperature distribution. In this paper, the analytical solution is found by using Galerkin vector, and it is compared by the results of FEM. For displacements of cylinder, analytical values are almost same as the results of FEM, but free expansion is not fit for analytical solution and the results of FEM. stresses from analytical solution and the results of FEM show good agreement also. but the results are different near the end boundary, since St. Venant principle is applied.

편심을 받은 고강도 콘크리트 기둥의 출력-모멘트 강도에 관한 실험 및 해석적 연구 (An Experimental and Analytical Study on Axial Force-Moment Capacity of High-Strength Concrete Column under Eccentric Loads)

  • 최창익;손혁수;이재훈
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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    • pp.468-474
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    • 1997
  • High strength concrete is a more effective material for columns subject to axial force and moment than for other structural elements. The purpose of this study is to review strength calculation methods for high strength concrete columus by comparison of analytical values and experimental results. The variables of column test under eccentric loading were concrete compressive strength, longitudinal steel ratio, and eccentricity of load. The tied column sections of 120×120mm and 210×210mm were tested and the eccentricity of load varied in the range from 0.16 times to 0.54 times the column depth. The analytical results using the stress-strain relationship to 0.54 times the column depth. The analytical results using the stress-strain relationship as well as the ACI's rectangular block, Zia's modified block, and the trapezoidal block are compared with experimentally obtained data, and discussed in this paper.

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Calculation of Winding Inductances for a Single-Phase Brushless DC Machine

  • Joo, Dae-Suk;Woo, Kyung-Il;Kim, Dae-Kyong
    • Journal of Magnetics
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    • 제17권3호
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    • pp.196-199
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    • 2012
  • This paper presents the analytical calculation of winding inductance for a single-phase brushless DC machine based on the magnetic circuit concept. The machine is used in the low power range of applications, such as ventilation fans, due to its simplicity and low cost. Since flux linkage is proportional to inductance, the calculation of winding inductance is of central importance. By comparison with experimental and analytical values, it is shown that proposed analytical expression is able to effectively predict the winding inductance of single-phase brushless DC machines at the design stage.

3배광법과 구역공간법의 정확도 평가 (Accuracy Evaluation of the Three-Curve Method and the Zonal Cavity Method)

  • 심상만;김창섭;김훈
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 1995년도 추계학술발표회논문집
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    • pp.53-59
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    • 1995
  • The accurcy and the application limits of the Three-Curve Method(TCM) and Zonal Cavity Method(ZCM) are evaluated. Average illuminance values are calculated by TCM and ZCM for various lighting conditions using general Diffusing Luminaires and Direct Luminaires. These values are compared with the values from Monte-Carlo Simulation(MCS) for the same lighting conditions. Accuracy of MCS was proved by Moon's Analytical Method.

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Rosen형 압전 트랜스포머의 집중등가회로를 사용한 승압비 및 효율 해석 (Voltage Gain and Efficiency Ana1ysis of Piezoelectric Transformer using Lumped Constant Equivalent Circuit)

  • 김만성;류주현;정회승;박창엽;정영호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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    • pp.183-189
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    • 1998
  • In this paper, The load characteristics on the voltage gain and efficiency were analyzed sing an lumped constant equivalent circuit of the piezoelectric transformer. These analytical results are confirmed by experiments. Theoretical values of voltage gain were nearly constant with experimental ones. However, It was shown that theoretical values of efficiency had higher values than experimental ones.

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고결모래의 강도정수와 일축압축강도 관계 (Relation of the Strength Parameter and the Unconfined Compressive Strength in Cemented Sand)

  • 이문주;최성근;조용순;이우진
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.14-21
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    • 2008
  • In this study, a series of CID tests were performed on gypsum-cemented specimens to determin the cohesion intercept and the confined stress start to break the cementation bonds (${q_i}'_{(BP)}$). And the relationships between the unconfined compressive strength ($q_{ucs}$) and cohesion intercept or ${q_i}'_{(BP)}$ were investigated. From the experiments, it was concluded that the friction angle of cemented sands is not affected by cementation while the cohesion intercept of cemented sands significantly influenced by cementation and is constant before ${q_i}'_{(BP)}$. By an analytical interpretation, the failure strength of cemented specimen could be represented by summation of the failure strength of uncemented specimen and the unconfined compressive strength of cemented one. And the cohesion intercept of cemented specimen was represented as a linear relation with the unconfined compressive strength. Those analytical values of failure strength and cohesion intercept almost coincided with the experimental values of those. In addition, the ${q_i}'_{(BP)}$ also could be related with unconfined compressive strength linearly.

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Vortex induced vibration analysis of a cylinder mounted on a flexible rod

  • Zamanian, Mehdi;Garibaldi, Luigi
    • Wind and Structures
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    • 제29권6호
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    • pp.441-455
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    • 2019
  • In this study, vortex induced vibrations of a cylinder mounted on a flexible rod are analyzed. This simple configuration represents the key element of new conception bladeless wind turbine (Whitlock 2015). In this study the structure oscillations equation coupled to the wake oscillation equation for this configuration are solved using analytical perturbation method, for the first time. An analytical expression that predicts the lock-in phenomena range of wind speed is derived. The discretized equations of motion are also solved using RKF45 numerical method. The equations of motion are discretized by Galerkin method. Free vibration mode shape of the structure taking into account the discontinuity of the cross section are used as comparison function. Numerical results are compared to the analytical results, and they show a satisfying agreement. The effect of system parameters on the oscillations of structure and wake as well as on the lock-in domain are presented. Moreover, it is shown that the values of wind speed triggering the start and the stop of the lock-in phenomenon, for increasing wind speed are different from those values obtained during the reverse process, i.e., when the wind speed decreases.