• Title/Summary/Keyword: validation studies

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Generator Testing and Model Validation for Thermal Plant (전력계통 안정성 향상을 위한 발전기 제어계 특성시험 및 모델링)

  • Cha, S.T.;Kim, Y.H.;Oh, S.I.;Choi, J.H.;Shin, J.H.;Shim, E.B.;Kwak, N.H.;Son, H.I.
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.473-474
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    • 2007
  • The Jeju power grid experienced several major power disturbances over the last decade. The postmortem studies of the incidents indicated that some of the generating units did not respond as predicted by system analysis & studies. Consequently, the Korean Power Exchange (KPX) mandated that all units (generators, excitation, governor and turbine systems) in the Korean network greater than or equal to 20MVA be tested to verify the generator reactive power limits as well as the dynamic model data being used for system studies. This paper presents field experiences of the authors in testing and modeling of steam turbines and their associated governors during the generator and model validation.

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Grid Discretization Study for the Efficient Aerodynamic Analysis of the Very Light Aircraft (VLA) Configuration

  • Sitio, Moses;Kim, Sangho;Lee, Jaewoo
    • International Journal of Aeronautical and Space Sciences
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    • v.14 no.2
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    • pp.122-132
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    • 2013
  • In this research the development of unstructured grid discretization solution techniques is presented. The purpose is to describe such a conservative discretization scheme applied for experimental validation work. The objective of this paper is to better establish the effects of mesh generation techniques on velocity fields and particle deposition patterns to determine the optimal aerodynamic characteristics. In order to achieve the objective, the mesh surface discretization approaches used the VLA prototype manufacturing tolerance zone of the outer surface. There were 3 schemes for this discretization study implementation. They are solver validation, grid convergence study and surface tolerance study. A solver validation work was implemented for the simple 2D and 3D model to get the optimum solver for the VLA model. A grid convergence study was also conducted with a different growth factor and cell spacing, the amount of mesh can be controlled. With several amount of mesh we can get the converged amount of mesh compared to experimental data. The density around surface model can be calculated by controlling the number of element in every important and sensitive surface area of the model. The solver validation work result provided the optimum solver to employ in the VLA model analysis calculation. The convergence study approach result indicated that the aerodynamic trend characteristic was captured smooth enough compared with the experimental data. During the surface tolerance scheme, it could catch the aerodynamics data of the experiment data. The discretization studies made the validation work more efficient way to achieve the purpose of this paper.

A Simulator for the Validation of Non-invasive Blood Pressure (NIBP) Monitoring Devices (자동혈압계 성능평가를 위한 인체혈압 시뮬레이터 개발)

  • Doh, Il;Lim, Hyun Kyoon;Ahn, Bongyoung;Chee, Youngjoon;Lee, Jongshill;OH, Jae Hoon
    • Journal of Biomedical Engineering Research
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    • v.38 no.3
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    • pp.111-115
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    • 2017
  • Blood pressure is one of the important vital signs for monitoring the medical condition of a patient. Automated NIBP(non-invasive blood pressure) monitoring devices calculate systolic and diastolic blood pressures from the oscillation in cuff pressure caused by a pulsation of an artery. To validate the NIBP devices, we developed a simulator to supply the oscillometric waveforms obtained from human subjects. The simulator provided pressure pulses to device-under-test and device readings were compared to the auscultatory references. Fully automated simulation system including OCR(optical character recognition) were developed and used for NIBP monitoring devices. The validation results using the simulator agreed well with previous clinical validation. More validation studies using the standardized oscillometric waveforms would be required for the replacement of clinical trials to validate a new automated NIBP monitoring device.

Cleaning Validation Studies for Multi-Purpose Facility : Vial Filling Machine (다품목 공용 제약설비인 바이알 충전기에 대한 세척공정 밸리데이션)

  • Choi, Han-Gon;Yang, Ho-Joon;Kim, Young-Ran;Sung, Jun-Ho;Hwang, Ma-Ro;Kim, Jong-Oh;Yong, Chul-Soon
    • Journal of Pharmaceutical Investigation
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    • v.39 no.4
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    • pp.263-267
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    • 2009
  • The purpose of this study is to evaluate the efficacy of stipulated cleaning process, and the prohibition of cross-contamination and microbiological contamination, which inadequate cleaning in multi-production could occur, through cleaning validation of multi-purpose facility used to produce five biopharmaceutical products as sterile injection. After production of five biopharmaceutical products such as hGH, rhGCSF, rhEPO, rhFSH and rhIFN using vial filling machine, the cleaning validation such as residual analysis of active ingredients or human serum albumin, measurement of total organic carbon (TOC), residual analysis of detergent and microbiological contamination were carried out. In the case of rhGH and rhGCSF clean validations, drug residues were not detected. Furthermore, in the case of rhEPO, rhFSH and rhIFN clean validations, human serum albumin residues were not detected. At TOC (total organic carbon) analysis, all clean validations gave the TOC of about average 137.93%, not more than 150% of acceptance criteria. At sodium analysis for the checking of residues of cleaning agent, sodium residues were not detected. In sterility test, they showed no microbiological contamination of bacteria and fungi. Thus, this cleaning validation was determined as successful in protection of cross-contamination and induction of safety in multi-purpose facility.

FEASIBILITY STUDIES FOR INFRASTRUCTURE CONSTRUCTION PROJECTS: HOW GOOD ARE THEY?

  • Khalied H. Hyari
    • International conference on construction engineering and project management
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    • 2007.03a
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    • pp.820-829
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    • 2007
  • This paper presents an evaluation of feasibility studies conducted to justify investments in infrastructure projects. An analysis of a previous feasibility study for a highway construction project is presented in this paper with an emphasis on the estimates and forecasts presented in that study in order to weigh expected benefits from the project against expected costs. The forecasted numbers are compared with actual data collected during the operation phase about the usage of the facility. The comparison reveals a huge difference between estimated numbers and actual numbers. Based on the lessons learned from the analyzed case study, recommendations are presented to improve feasibility studies for infrastructure projects including: peer review of feasibility studies; before-and-after feasibility studies; and defined scope and methodology for feasibility studies. Decision makers are advised to take outcomes of feasibility studies for infrastructure projects with extreme caution as some studies may provide erroneous and misleading input to their decisions regarding investment in infrastructure projects.

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A Study on Software Implementation for Validation of Electronic Navigational Chart Regarding Standard Check for S-10X Data (S-10X 데이터 표준 검사를 위한 전자해도 검증 소프트웨어 구현에 관한 연구)

  • LEE, Ha-Dong;KIM, Ki-Su;CHOI, Yun-Su;KIM, Ji-Yoon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.1
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    • pp.83-95
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    • 2018
  • With recent technological advances in the shipbuilding industry, vessels have been improved in size and performance. As a result, an accident such as grounding, caused by a single ship-to-ship collision, could lead to a large-scale maritime disaster. Considering the seriousness of the situation, the international community has been consistently updating the standards for Electronic Navigational Chart(ENC) to improve the maritime safety. S-57, the existing ENC standard governed by the International Hydrographic Organization(IHO), includes standards for generating conventional binary-type ENC data sets. The S-57 standard, however, has not been updated since the release of Version 3.1 in December 2000. Since then, the standard has failed to reflect technological development regarding maritime spacial information, which has been consistently improving. In an effort to address this concern, the IHO designated S-100, i.e., the next-generation ENC production standard. S-100 differs from S-57 in data exchange type. Contrary to the conventional ENC standards, which use binary-type data, S-10X, based on the next-generation ENC standards, uses ENC data composed of Feature Catalogue, Portrayal Catalogue, and GML. Considering this fact, it is necessary to update S-58, the ENC validation check standard, or designate a new standard for ENC validation checks. This study is developed own software to implement validation checks for new types of data, and identified improvement points based on the test results.

Statistical bioinformatics for gene expression data

  • Lee, Jae-K.
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2001.08a
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    • pp.103-127
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    • 2001
  • Gene expression studies require statistical experimental designs and validation before laboratory confirmation. Various clustering approaches, such as hierarchical, Kmeans, SOM are commonly used for unsupervised learning in gene expression data. Several classification methods, such as gene voting, SVM, or discriminant analysis are used for supervised lerning, where well-defined response classification is possible. Estimating gene-condition interaction effects require advanced, computationally-intensive statistical approaches.

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Chemical Genomics with Natural Products

  • Jung, Hye-Jin;Ho, Jeong-Kwon
    • Journal of Microbiology and Biotechnology
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    • v.16 no.5
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    • pp.651-660
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    • 2006
  • Natural products are a rich source of biologically active small molecules and a fertile area for lead discovery of new drugs [10, 52]. For instance, 5% of the 1,031 new chemical entities approved as drugs by the US Food and Drug Administration (FDA) were natural products between 1981 and 2002, and another 23% were natural product-derived molecules [53]. These molecules have evolved through millions of years of natural selection to interact with biomolecules in the cells or organisms and offer unrivaled chemical and structural diversity [14, 37]. Nonetheless, a large percentage of nature remains unexplored, in particular, in the marine and microbial environments. Therefore, natural products are still major valuable sources of innovative therapeutic agents for human diseases. However, even when a natural product is found to exhibit biological activity, the cellular target and mode of action of the compound are mostly mysterious. This is also true of many natural products that are currently under clinical trials or have already been approved as clinical drugs [11]. The lack of information on a definitive cellular target for a biologically active natural product prevents the rational design and development of more potent therapeutics. Therefore, there is a great need for new techniques to expedite the rapid identification and validation of cellular targets for biologically active natural products. Chemical genomics is a new integrated research engine toward functional studies of genome and drug discovery [40, 69]. The identification and validation of cellular receptors of biologically active small molecules is one of the key goals of the discipline. This eventually facilitates subsequent rational drug design, and provides valuable information on the receptors in cellular processes. Indeed, several biologically crucial proteins have already been identified as targets for natural products using chemical genomics approach (Table 1). Herein, the representative case studies of chemical genomics using natural products derived from microbes, marine sources, and plants will be introduced.

Development and Validation of a Cancer Awareness Questionnaire for Malaysian Undergraduate Students of Chinese Ethnicity

  • Loo, Jo Lin;Ang, Yee Kwang;Yim, Hip Seng
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.565-570
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    • 2013
  • Objectives: To describe the development and validation of a cancer awareness questionnaire (CAQ) based on a literature review of previous studies, focusing on cancer awareness and prevention. Materials and Methods: A total of 388 Chinese undergraduate students in a private university in Kuala Lumpur, Malaysia, were recruited to evaluate the developed self-administered questionnaire. The CAQ consisted of four sections: awareness of cancer warning signs and screening tests; knowledge of cancer risk factors; barriers in seeking medical advice; and attitudes towards cancer and cancer prevention. The questionnaire was evaluated for construct validity using principal component analysis and internal consistency using Cronbach's alpha (${\alpha}$) coefficient. Test-retest reliability was assessed with a 10-14 days interval and measured using Pearson product-moment correlation. Results: The initial 77-item CAQ was reduced to 63 items, with satisfactory construct validity, and a high total internal consistency (Cronbach's ${\alpha}$=0.77). A total of 143 students completed the questionnaire for the test-retest reliability obtaining a correlation of 0.72 (p<0.001) overall. Conclusions: The CAQ could provide a reliable and valid measure that can be used to assess cancer awareness among local Chinese undergraduate students. However, further studies among students from different backgrounds (e.g. ethnicity) are required in order to facilitate the use of the cancer awareness questionnaire among all university students.

Validation of a Rodent Nose-only Exposure System for Inhalation Toxicity Evaluation of Cigarette Smoke (담배 흡입독성 평가를 위한 설치류 담배연기노출시스템의 유효화)

  • Sohn, Hyung-Ok;Lee, Hyeong-Seok;Shin, Han-Jae;Park, Chul-Hoon;Yoo, Ji-Hye;Jang, Mi;Hyun, Hak-Chul
    • Journal of the Korean Society of Tobacco Science
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    • v.36 no.1
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    • pp.20-25
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    • 2014
  • As part of a balanced testing battery, subchronic inhalation studies on rats are performed to ensure that proposed cigarette modifications do not increase the toxicity of smoke and to demonstrate any instances where a modification may actually contribute to harm reduction. For subchronic inhalation studies with aerosols, the OECD suggests an exposure regimen of 6 hours/day (OECD Guideline 413, 1981), but alternative regimens have also been published: 1 hour/day and $2{\times}1$ hour/day. The aim of this study was to validate a rodent nose-only exposure system for the assessment of inhalation toxicity of cigarette smoke. In this study, cigarette smoke exposure system is consisted of cigarette smoke generator, smoke concentration adjusting system, and 20-port nose-only exposure system. Male SD rats were exposed for 35 days ($2{\times}1$ hour/day) to 3R4F Reference cigarette smoke and analysed major monitoring items of OECD Gudeline 413. WTPM, was measured in the test atmosphere, respiratory function (Buxco Biosystems) during exposure, postexposure urinary exposure biomarkers and alveolar neutrophiles in BAL fluid (Day 35) were evaluated. Validation demonstrated steady WTPM ($257{\pm}20ug/L$, $502{\pm}27ug/L$) and spatial uniformity (<10%). Nose port temperature ($22{\sim}26^{\circ}C$ and RH (45~75%) were acceptable over 35 days. Reductions in respiratory rate and minute volume and increase in the neutrophiles in BALF and the urinary exposure biomarkers were observed cigarette smoke dose dependently. This validation and 35-day inhalation study has shown that the rodent nose-only exposure system may be useful in the inhalation toxicity assessment of cigarette smoke.