• Title/Summary/Keyword: Technical Factor

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Partial Safety Factors for Geotechnical Bearing Capacity of Port Structures (항만구조물 지반지지력 산정을 위한 부분안전계수 결정)

  • Yoon, Gil-Lim;Yoon, Yeo-Won;Kim, Hong-Yeon;Kim, Baeck-Oon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.3
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    • pp.156-162
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    • 2010
  • When eccentric or inclined load acts on foundation of the port & harbor structures, partial safety factors of bearing capacity limit state were estimated using reliability analysis. Current Korean technical standards of port and harbor structures recommend to estimate the geotechnical bearing capacity using the simplified Bishop method. In practice, however, simple method of comparing ground reaction resistance with allowable bearing capacity has been mostly used by design engineers. While the simple method gives just one number fixed but somewhat convenient, it could not consider the uncertainty of soil properties depending on site by site. Thus, in this paper, partial safety factors for each design variable were determined so that designers do perform reliability-based level 1 design for bearing capacity limit state. For these, reliability index and their sensitivities were gained throughout the first order reliability method(FORM), and the variability of the random variables was also considered. In order to verify partial safety factors determined here, a comparison with foreign design codes was carried out and were found to be reasonable in practical design.

A Study on the Stress-Strain Prediction of Silty Clay (점성토(粘性土)의 응력(應力) - 변형(變形) 추정(推定)에 관(關)한 연구(硏究))

  • Cho, Seong Seup;Kang, Yea Mook;Chung, Seong Gyu;Yun, Hyun Chung
    • Korean Journal of Agricultural Science
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    • v.19 no.1
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    • pp.65-78
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    • 1992
  • The paper describes the comparison between observed and predicted stress-strain characteristics of marine silty clay in Dangjin district. For prediction, the hyperbolic model which is applied the parameters acquiring by physical and triaxial compression test was adopted, and the obtained results were summarized as follows: 1. The Young's modulus were increased with decreasing of moisture contents and increasing of dry density. 2. The most affective factor to hyperbolic model is lateral stress and dry density. and than cohesion and internal friction angle. 3. The comparision between the statistical and hyperbolic values of maximum deviator stress have few accordance. and the statisticals is lower than the hyperbolics. 4. Without. much labor and tiresome procedures, effective computer program was made and applied, but technical procedure for prevents test errors of parameter calculation is importants.

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G1 Arrest of the Cell Cycle by Gomisin N, a Dibenzocyclooctadiene Lignan, Isolated from Schizandra chinensis Baill in Human Leukemia U937 Cells (오미자에서 분리된 dibenzocyclooctadiene lignan의 일종인 gomisin N에 의한 인체혈구암세포의 세포주기 G1 arrest 유발)

  • Park, Cheol;Hwang, Hye-Jin;Choi, Byung-Tae;Choi, Tae-Hyun;Kim, Byung-Woo;Choi, Young-Whan;Choi, Yung-Hyun
    • Journal of Life Science
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    • v.20 no.7
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    • pp.977-982
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    • 2010
  • We investigated the anti-cancer effects of two dibenzocyclooctadiene lignans, gomisin A and gomisin N, isolated from Schizandra chinensis Baill, in human promyelocytic U937 cells. Gomisin N, but not gomisin A, inhibited cell growth in a concentration-dependent manner, which was associated with the induction of G1 arrest of the cell cycle. G1 arrest induced by gomisin N was correlated with down-regulation of cyclin E, cyclin-dependent kinase (Cdk) 2 and Cdk4, and a concomitant up-regulation of Cdk inhibitors such as p16 (INK4A) and p21 (WAF1/CIP1). Furthermore, gomisin N inhibited phosphorylation of retinoblastoma protein (pRB) and p130, and expression of transcription factor E2Fs. The results indicated that growth inhibition by gomisin N is related to cell cycle arrest at G1 in U937 cells and these findings suggest that gomisin N may be a useful chemotherapeutic agent.

An Empirical Study of the Recovery Experiment in Clinical Chemistry (임상화학검사실에서 회수율 실험의 실증적 연구)

  • Chang, Sang-Wu;Lee, Sang-Gon;Song, Eun-Young;Park, Yong-Won;Park, Byong-Ok
    • Korean Journal of Clinical Laboratory Science
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    • v.38 no.3
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    • pp.184-188
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    • 2006
  • The purpose of the recovery experiment in clinical chemistry is performed to estimate proportional systematic error. We must know all measurements have some error margin in measuring analytical performance. Proportional systematic error is the type of error whose magnitude increases as the concentration of analyte increases. This error is often caused by a substance in the sample matrix that reacts with the sought for analyte and therefore competes with the analytical reagent. Recovery experiments, therefore, are used rather selectively and do not have a high priority when another analytical method is available for comparison purposes. They may still be useful to help understand the nature of any bias revealed in the comparison of kit experiments. Recovery should be expressed as a percentage because the experimental objective is to estimate proportional systematic error, which is a percentage type of error. Good recovery is 100.0%. The difference between 100 and the observed recovery(in percent) is the proportional systematic error. We calculated the amount of analyte added by multiplying the concentration of the analyte added solution by the dilution factor(mL standard)/(mL standard + mL specimen) and took the difference between the sample with addition and the sample with dilution. When making judgments on method performance, the observed that the errors should be compared to the defined allowable error. The average recovery needs to be converted to proportional error(100%/Recovery) and then compared to an analytical quality requirement expressed in percent. The results of recovery experiments were total protein(101.4%), albumin(97.4%), total bilirubin(104%), alkaline phosphatase(89.1%), aspartate aminotransferase(102.8), alanine aminotransferase(103.2), gamma glutamyl transpeptidase(97.6%), creatine kinase(105.4%), lactate dehydrogenase(95.9%), creatinine(103.1%), blood urea nitrogen(102.9%), uric acid(106.4%), total cholesterol(108.5), triglycerides(89.6%), glucose(93%), amylase(109.8), calcium(102.8), inorganic phosphorus(106.3%). We then compared the observed error to the amount of error allowable for the test. There were no items beyond the CLIA criterion for acceptable performance.

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Knowledge and Attitudes about HIV/AIDS among Health Care Officers in S. Korea (보건복지 공무원의 에이즈에 대한 지식과 태도에 대한 연구)

  • Choi, Eun-Jeung;Kim, Wha-Son;Jung, Sun-Bok;Whang, In-Sook;Yang, Jeoung-Nam
    • Korean Journal of Health Education and Promotion
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    • v.26 no.5
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    • pp.41-55
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    • 2009
  • Objective: This study explores the level of knowledge and attitude towards HIV/AIDS and the relationship between knowledge and attitude among social workers and nurses working in the public sector in Gwangju, S. Korea. Methods: The sample was composed of 121 nurse and 124 social workers. For the purpose of this research participants completed a questionnaire designed to assess their knowledge and attitudes about HIV/AIDS. The data was collected between December 2008 and January 2009. All data was analyzed using SPSS WIN version 12.0 for technical statistics. t-Test, ANOVA and multiple regression analysis was employed. Results: First, the result of this research showed that the level of participants knowledge on HIV/AIDS was 85.9%. The nurses score was significantly higher than social workers on knowledge. Second, the outcome also showed that nurses generally had a more positive attitude about HIV/AIDS patients than social workers but it was not significant. Third, participant's attitudes towards HIV/AIDS was significantly influenced by the level of knowledge and previous education about HIV/AIDS. Fourth, the results also showed that knowledge on HIV/AIDS is the most important influencing factor towards the participants attitude. Conclusion: This result has important implications for future education programs designed for health care professionals including nurses and social workers. Given the importances of the role of public officers as practitioners and policy makers on HIV/AIDS, the education program should not only focus on lectures but also include a sharing of practical experience and knowledge.

DEA Models and Application Procedure for Performance Evaluation on Governmental Funding Projects for IT Small and Medium-sized Enterprises with Exogenously Fixed Variables of Corporate Competency (기업역량을 고려한 외생고정변수를 갖는 IT중소기업 정부자금지원정책 성과평가를 위한 DEA모형 및 활용절차)

  • Park, Sung-Min;Kim, Heon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.5B
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    • pp.364-378
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    • 2008
  • Data Envelopment Analysis(DEA) models can be used for performance evaluation on governmental funding projects for IT small and medium-sized enterprises associated with multiple-outputs/multiple-inputs. In order to enhance the accuracy of DEA efficiency scores, DEA models with exogenously fixed variables are required where the corporate competency is taken into account. Additionally, it is necessary to use multiple DEA basic as well as extended models so as to relax the restriction on the performance evaluation to relying on a single DEA model. In this study; 1)a DEA data structure is designed including exogenously fixed variables representing corporate asset, revenue and the number of employees at the point in time that the governmental funding project concerned is initiated; 2)DEA basic as well as extended models are established according to the DEA data structure presented abovementioned; and 3)a case study is illustrated with an empirical testbed dataset. As for the DEA basic models, CCR, BCC, Super-efficiency model are adopted. The DEA extended models are developed based on the models associated with noncontrollable and nondiscretionary variables. In the case study, it is explained a comparison of DEA models and also major numerical outcomes such as efficiency scores, ranks derived from each DEA model are integrated using Analytic Hierarchy Process(AHP) weights. Performance significance with DEA efficiency scores between technical categories are tested based not only on parametric but also nonparametric single-factor analysis of variance method.

In Vitro Isolation and Proliferation of Mouse Male Germ-Line Stem Cells (생쥐 생식줄기세포의 체외 분리 및 증식)

  • 김수경;김계성
    • Journal of Embryo Transfer
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    • v.18 no.3
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    • pp.243-248
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    • 2003
  • Sperrnatogenesis, the process by which the male germ-line stem cells(GSCs; type A spermatogonia) divide and differentiate to produce the mature spermatozoa, occurs in the seminiferous tubules of the testis. The GSCs proliferate actively to produce two types of cells: other GSCs and differentiating spermatogonia. GSCs have unipotentcy, devoted solely to the generation of sperm. The function of GSCs has broad implications for development, disease, and evolution. Spermatogenesis is fundamental for propagation of species and the defects of this system can result in infertility or disease. The ability to identify, isolate, culture, and alter GSCs will allow powerful new approaches in animal transgenesis and human gene therapy relating to infertility. Until recently, research on stem cells in the testis has been limited because of technical difficulties in isolating and identifying these cell populations. Here, we were trying to find out optimal conditions for in vitro culture of GSCs for identifying and isolating GSCs. We collected mouse GSCs from 3-days old mouse by two-step enzyme digestion method. GSCs were plated and grown on mouse embryonic fibroblasts in Dulbecco's modified Eagle's medium (DMEM) containing 15% fatal bovine serum, 10 mM 2-mercaptoethanol, 1% non-essential amino acids, 1 ng/$m\ell$ bFGF, 10 $\mu$M forskolin, 1500 U/$m\ell$ human recombinant leukemia inhibitory factor (LIF). Over a period 3∼5 days, GSCs gave rise to large multicellular colonies resembling those of mouse pluripotent stem cells. After 5th passages, cells within the colonies continued to be alkaline phosphatase and Oct-4 positive and tested positive against a panel of two immunological markers(Integrin $\alpha$ 6 and Integrin $\beta$ 1) that have been recognized generally to characterize GSCs. SSEA-1, SSEA-3, and SSEA-4 also showed positive signals. Based on our data, these GSCs-derived cultures meet the criteria for GSCs itself and even other pluripotent stem cells. We reported here the establishment of in vitro cultures from mouse male GSCs.

Aesthetic elements in Product Design of Korean and Chinese's Consumer preference (한국.중국 소비자 선호 제품디자인의 심미성 요소 연구)

  • Jeong, Su-Kyoung;Hong, Jung-Pyo
    • Archives of design research
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    • v.19 no.2 s.64
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    • pp.63-72
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    • 2006
  • The design in modern industrial society is the core of corporate administrational strategy and a factor that determines the competitiveness of a country. And the process of purchasing products is the matter related to the awareness of design which expresses the desire to own the design product that consumers prefer, implying that the aesthetic feature of product has become a critical characteristics of product design rather than the technical function of product. In this regard, the development of product design with a new dimension is urgently called for, by analyzing and shedding light on the aesthetic features of factors related to the preference of consumers. This study considers the preceding studies on the aesthetic factors and the reaction of customers to the product design to figure out the importance of factors related to the preference of customers, in an effort to shed light on the aesthetic factors that affect the customers' preference of product and the evaluation of product. In addition to that, this study investigated the preference that Korean and Chinese customers display toward the product and assessed the aesthetic features of preferred product in order to come to the conclusion from the experiment and analysis on how much effect the aesthetic factors and the aesthetic factors by product have on the preference of customers. Therefore, this study tries to propose the data that can be useful for the design of product targeted for consumers in Korea and China, by shedding light on what aesthetic factors that products preferred by consumers in Korea and China have and how much effect such factors have on the preference of consumers in an attempt to provide the guideline on the aesthetic factors of the product design.

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Analysis of Siting Criteria of Overseas Geological Repository (II): Hydrogeology (국외 심지층 처분장 부지선정기준 분석 (II) : 수리지질)

  • Jung, Haeryong;Kim, Hyun-Joo;Cheong, Jae-Yeol;Lee, Eun Yong;Yoon, Jeong Hyoun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.11 no.3
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    • pp.253-257
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    • 2013
  • Geology, hydrogeology, and geochemistry are the main technical siting factors of a geological repository for spent nuclear fuels. This paper evaluated the siting criteria of overseas geological repository with related to hydrogeologic properties, such as hydraulic conductivity, partitioning coefficient, dispersion coefficient, boundary condition, and water age. Each country establishes the siting criteria based on its important geological backgrounds and information, and social environment. For example, Sweden and Finland that have decided a crystalline rock as a host rock of a geological repository show different siting criteria for hydraulic conductivity. In Sweden, it is preferable to avoid area where the hydraulic conductivity on a deposition hole scale (~30m) exceeds $10^{-8}m/s$, whereas Finland does not decide any criterion for the hydraulic conductivity because of limited data for it. In addition, partitioning coefficients should be less than 10-1 of average value in Swedish crystalline bedrock. However, the area where shows 100 times less than average partitioning coefficients of radionuclides in crystalline rock should be avoided in Sweden. In German, the partitioning coefficients for the majority of the long-term-relevant radionuclides should be greater than or equal to $0.001m^3/kg$. Therefore, it is strongly required to collect much and exact information for the hydrogeologic properties in order to set up the siting criteria.

COMPARISON OF OPERATIVE TECHNIQUES BETWEEN FEMALE AND MALE DENTISTS IN CLASS 2 AND CLASS 5 RESIN COMPOSITE RESTORATIONS (2급/ 5급 와동 복합레진 수복 술식에 대한 남녀 치과 의사의 비교)

  • Chang, Ju-Hea;Kim, Hae-Young;Son, Ho-Hyun
    • Restorative Dentistry and Endodontics
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    • v.35 no.2
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    • pp.116-124
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    • 2010
  • This study aimed to assess whether the gender of the dental practitioner affects operative techniques in class 2 and class 5 resin composite restorations. In 2008, a nationwide survey was given to Korean dentists. Total 12,193 e-mails were distributed, 2,632 were opened by recipients, and 840 responses were collected. Of the respondents, 78.9% were male and 21.1% were female. The gender distribution in the age groups between respondents and the total population did not differ (p > 0.05). A chi-square test was used to compare technical differences between female and male dentists. A multiple logistic regression analysis was performed to assess the association between gender and operative techniques in resin composite restoration. For class 2 resin composite restoration, female dentists were 1.87 times more likely than male dentists to do multiple incremental fillings (four layers or more) and 2.72 times more likely than males to spend 30 minutes or more for the treatment (p < 0.05). For class 5 resin composite restoration, female dentists were 2.69 times more likely than their male counterparts to use a cavity base or liner, 1.83 times more likely to do multiple incremental fillings (four layers or more) and 1.63 times more likely to spend 20 minutes or more for the procedure (p < 0.05). The gender factor was influential to individual operative techniques in restorative treatment.