• Title/Summary/Keyword: scale-model

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A Study on the cognition of Busan Port Container Terminal Operator's strategies and effective measures (부산항 컨테이너터미널 운영전략 효과의 인식에 관한 연구)

  • Yun, Eun-Ju;Ahn, Ki-Myung
    • Journal of Korea Port Economic Association
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    • v.29 no.4
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    • pp.175-199
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    • 2013
  • The purpose of this paper is tthe first, diagnosing the effect of terminal operating strategy which Busan Port container operators established and executed by the strategy execution process (XPP) model, second, enhancing the competitiveness of Busan Port Container Terminal by presenting ways to improve the executive ability of strategies. In order to achieve the purpose, this study utilized XPP 6 steps diagnostic variables of Kaplan and Dr. Norton for problems of the strategy execution of Busan Port container operators and conducted the survey of 7-point scale targeting employees of Busan Port container operators for the variable measurement.

Preliminary Research of Regenerative Cooling for Small Scale Combustors (소형 연소기를 위한 재생냉각의 선행연구)

  • Jang, Dong-Wuk;Jo, Sung-Kwon;Cho, Hwang-Rae;Bang, Jeong-Seok;Kwon, Se-Jin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.163-170
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    • 2011
  • Applicability of regenerative cooling in 2,500 N-class bipropellant thruster using hydrogen peroxide and kerosene was considered for improvement performance and application in various missions. Calculation was performed by one dimensional approach using hydrogen peroxide as a coolant. In designed regenerative cooling thruster, heat flux at nozzle throat was estimated at 18 ~ 20 $MW/m^2$. Designed cooling channel width and height were 2.5 mm and 0.5 mm, respectively. Based on designed cooling channel configuration, flat plate model was manufactured and tested for estimation of pressure drop in cooling channel, and CFD analysis was compared with the test result. The maximum error between CFD analysis and experimental result was approximately 13% and average error was approximately 5%.

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Flutter analysis of Stonecutters Bridge

  • Hui, Michael C.H.;Ding, Q.S.;Xu, Y.L.
    • Wind and Structures
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    • v.9 no.2
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    • pp.125-146
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    • 2006
  • Stonecutters Bridge of Hong Kong is a cable-stayed bridge with two single-column pylons each 298 m high and an aerodynamic twin deck. The total length of the bridge is 1596 m with a main span of 1018 m. The top 118 m of the tower will comprise structural steel and concrete composite while the bottom part will be of reinforced concrete. The bridge deck at the central span will be of steel whilst the side spans will be of concrete. Stonecutters Bridge has adopted a twin-girder deck design with a wide clear separation of 14.3 m between the two longitudinal girders. Although a number of studies have been conducted to investigate the aerodynamic performance of twin-girder deck, the actual real life application of this type of deck is extremely limited. This therefore triggered the need for conducting the present studies, the main objective of which is to investigate the performance of Stonecutters Bridge against flutter at its in-service stage as well as during construction. Based on the flutter derivatives obtained from the 1:80 scale rigid section model experiment, flutter analysis was carried out using 3-D finite element based single parameter searching method developed by the second author of this paper. A total of 6 finite element models of the bridge covering the in-service stage as well as 5 construction stages were established. The dynamic characteristics of the bridge associated with these stages were computed and applied in the analyses. Apart from the critical wind speeds for the onset of flutter, the dominant modes of vibration participating in the flutter vibration were also identified. The results indicate that the bridge will be stable against flutter at its in-service stage as well as during construction at wind speeds much higher than the verification wind speed of 95 m/s (1-minute mean).

Influence of ventilation rate on the aerodynamic interference between two extra-large indirect dry cooling towers by CFD

  • Ke, S.T.;Liang, J.;Zhao, L.;Ge, Y.J.
    • Wind and Structures
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    • v.20 no.3
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    • pp.449-468
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    • 2015
  • Current wind-resistance designs of large-scale indirect dry cooling towers (IDCTs) exclude an important factor: the influence of the ventilation rate for radiator shutter on wind loads on the outer surfaces of the tower shell. More seemingly overlooked aspects are the effects of various ventilation rates on the wind pressure distribution on the tower surfaces of two IDCTs, and the feature of the flow field around them. In order to investigate the effects of the radiator shutter ventilation rates on the aerodynamic interference between IDCTs, this paper established the numerical wind tunnel model based on the Computational Fluid Dynamic (CFD) technology, and analyzed the influences of various radiator shutter ventilation rates on the aerodynamic loads acting upon a single and two extra-large IDCTs during building, installation, and operation stages. Through the comparison with the results of physical wind tunnel test and different design codes, the results indicated that: the influence of the ventilation rate on the flow field and shape coefficients on the outer surface of a single IDCT is weak, and the curve of mean shape coefficients is close to the reference curve provided by the current design code. In a two-tower combination, the ventilation rate significantly affects the downwind surface of the front tower and the upwind surface of the back tower, and the larger positive pressure shifts down along the upwind surface of the back tower as the ventilation rate increases. The ventilation rate significantly influences the drag force coefficient of the back tower in a two-tower combination, the drag force coefficient increases with the ventilation rate and reaches the maximum in a building status of full ventilation, and the maximum drag coefficient is 11% greater than that with complete closure.

A study on the characteristics of multi load transfer ground anchor system (다중정착 지반앵커의 하중전달 특성에 관한 연구)

  • Kim, Ji-Ho;Jeong, Hyeon-Sic;Kwon, Oh-Yeob;Shin, Jong-Ho
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.16 no.1
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    • pp.25-50
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    • 2014
  • In order to identify a load transfer mechanism of ground anchors, the behavior of multi load transfer ground anchor systems was investigated and compared with those of compression type anchors and tension type anchors. Large scale model tests were performed and stress-strain relationships were obtained. The load transfer mechanism of ground anchors was also investigated in the field tests. Finally, numerical analyses to predict the load-displacement relationships of anchors were conducted. It is concluded that the load transfer characteristics of MLT anchors are mechanically much more superior in the pull-out resistance effect than those of existing compression and tension type anchors. From the results of research work, we could suggest that the max pull-out capacity of anchor capacity to each the soil condition. Also, the MLT anchors can be used to achieve both structural enhancement and economic construction in earth retaining or supporting structures.

Damage detection of subway tunnel lining through statistical pattern recognition

  • Yu, Hong;Zhu, Hong P.;Weng, Shun;Gao, Fei;Luo, Hui;Ai, De M.
    • Structural Monitoring and Maintenance
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    • v.5 no.2
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    • pp.231-242
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    • 2018
  • Subway tunnel structure has been rapidly developed in many cities for its strong transport capacity. The model-based damage detection of subway tunnel structure is usually difficult due to the complex modeling of soil-structure interaction, the indetermination of boundary and so on. This paper proposes a new data-based method for the damage detection of subway tunnel structure. The root mean square acceleration and cross correlation function are used to derive a statistical pattern recognition algorithm for damage detection. A damage sensitive feature is proposed based on the root mean square deviations of the cross correlation functions. X-bar control charts are utilized to monitor the variation of the damage sensitive features before and after damage. The proposed algorithm is validated by the experiment of a full-scale two-rings subway tunnel lining, and damages are simulated by loosening the connection bolts of the rings. The results verify that root mean square deviation is sensitive to bolt loosening in the tunnel lining and X-bar control charts are feasible to be used in damage detection. The proposed data-based damage detection method is applicable to the online structural health monitoring system of subway tunnel lining.

Development and Evaluation of Multilingual Education Materials to Promote Immigrant Women's Adaptation to Pregnancy (이주여성의 임신적응증진을 위한 다국어 교육자료 개발과 평가)

  • Kim, Kyung Won;Baik, Sung Hee;Jeong, Geum Hee
    • Women's Health Nursing
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    • v.20 no.4
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    • pp.235-245
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    • 2014
  • Purpose: This study was done to develop and evaluate multilingual education materials to promote health and adaptation to pregnancy for immigrant women in Korea. Methods: This study had three procedures: First, contents of the education materials were developed according to pregnant women's needs, literature reviews, and group discussion. Details in contents were constructed based on Roy's adaptation model; Second, validity verification and translation of education materials were accomplished; Third, evaluation of the education materials was done through a survey of immigrant women. Results: The education materials were developed in six languages (Korean, English, Chinese, Vietnamese, Filipino, and Cambodian). The title is "Healthy mother, happy family: eight-step guide to a healthy pregnancy". It was composed of an eight-step guide to healthy pregnancy, self-examination check list, websites for childbirth education and information, and guidelines on education materials in a brochure. In the evaluation, the average response score for the questionnaire items was high (3.23 on a four-point Likert scale). The average score for Cambodian immigrants was the highest of all immigrant women. Conclusion: Multilingual education materials developed in this research will help community health nurses to manage pregnancies for immigrant women and will be useful for health education for these women.

Turkish Female Academician Self-Esteem and Health Beliefs for Breast Cancer Screening

  • Avci, Ilknur Aydin;Kumcagiz, Hatice;Altinel, Busra;Caloglu, Ayse
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.1
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    • pp.155-160
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    • 2014
  • Purpose: This study aimed to analyse female academician health beliefs for breast cancer screening and levels of self-esteem. Materials and Methods: This cross-sectional study was conducted between October 2010 and March 2011, covering female academicians working in all faculties and vocational schools at Ondokuz Mayis University, except for the ones in the field of health (n=141). Data was collected using a questionnaire developed by researchers in the light of the related literature, the Champion's Health Belief Model Scale for Breast Cancer, and the Coopersmith Self-Esteem Inventory. Descriptive statistics, the t-test, Mann-Whitney U and correlation analysis were used to analyze the data with the SPSS 13.0 statistical package. Results: 53.8% of the participants were single, 58.6% did not have children, 80.7% had regular menstrual cycles, 28.3% was taking birth control pills, 17.9% were undergoing hormone therapy, 11% suffered breast problems, 8.3% had relatives with breast cancer, 78,6% knew about breast self-examination (BSE), 68.3% was performing BSE, 16.2% were performing BSE monthly, 17.9% had had mammograms, and 30.3% had undergone breast examinations conductedby physicians. The women who had breast physical examinations done by physicians had higher susceptibility, self-efficacy and health motivation, and fewer barriers to mammography than those who did not have breast physical examinations. Conclusions: There was a relationship between the female academician self-esteem and their perceived seriousness of breast cancer, perceived barriers to BSE and health motivation. Our Turksih female academicians had medium levels of self-esteem.

Predictive Factors of Postoperative Pain and Postoperative Anxiety in Children Undergoing Elective Circumcision: A Prospective Cohort Study

  • Zavras, Nick;Tsamoudaki, Stella;Ntomi, Vasileia;Yiannopoulos, Ioannis;Christianakis, Efstratios;Pikoulis, Emmanuel
    • The Korean Journal of Pain
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    • v.28 no.4
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    • pp.244-253
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    • 2015
  • Background: Although circumcision for phimosis in children is a minor surgical procedure, it is followed by pain and carries the risk of increased postoperative anxiety. This study examined predictive factors of postoperative pain and anxiety in children undergoing circumcision. Methods: We conducted a prospective cohort study of children scheduled for elective circumcision. Circumcision was performed applying one of the following surgical techniques: sutureless prepuceplasty (SP), preputial plasty technique (PP), and conventional circumcision (CC). Demographics and base-line clinical characteristics were collected, and assessment of the level of preoperative anxiety was performed. Subsequently, a statistical model was designed in order to examine predictive factors of postoperative pain and postoperative anxiety. Assessment of postoperative pain was performed using the Faces Pain Scale (FPS). The Post Hospitalization Behavior Questionnaire study was used to assess negative behavioral manifestations. Results: A total of 301 children with a mean age of $7.56{\pm}2.61$ years were included in the study. Predictive factors of postoperative pain measured with the FPS included a) the type of surgical technique, b) the absence of siblings, and c) the presence of postoperative complications. Predictive factors of postoperative anxiety included a) the type of surgical technique, b) the level of education of mothers, c) the presence of preoperative anxiety, and d) a history of previous surgery. Conclusions: Although our study was not without its limitations, it expands current knowledge by adding new predictive factors of postoperative pain and postoperative anxiety. Clearly, further randomized controlled studies are needed to confirm its results.

A Study on the Effect of Cumulus Parameterization and Microphysics on Ozone Simulations during Long-range Transport Process over Northeast Asia (동북아 장거리 수송 과정에서 적운 모수화 및 미세물리과정이 오존 모사농도에 미치는 영향 연구)

  • Kang, Jeong-Eon;Kim, Cheol-Hee
    • Journal of Korean Society for Atmospheric Environment
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    • v.29 no.2
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    • pp.135-151
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    • 2013
  • This study has been carried out to analyze the sensitivity of ozone concentrations by employing different options of cumulus parameterization schemes (CPSs) and microphysics schemes in MM5 models. These sensitivity tests were applied to long-range transport case of higher ozone over Northeast Asia. Employed CPS schemes are Betts-Miller (BM), Grell (GR), Kain-Fritsch2 (KF2), Anthes-Kuo (AK), None scheme (grid scale physics only), and four microphysics used here are Simple ice, Reisner1, Reisner2, Schultz scheme in MM5. We chose two cases of high ozone long range transport case by employing both concentrations ozone level and backward trajectory model. The results showed that modeled ozone concentrations indicated about 10% differences among CPSs. Of the all options, GR and KF2 (for CPS), and Rersiner-1 and Resiner-2 (for microphysics) showed relatively good and stable variations against ensemble mean values. For both CPS and microphysics schemes, the difference of precipitation arising from different parameterization schemes was significant by itself, but the resultant ozone variations showed only marginal. But the cloud fraction differences arising from different parameterization schemes showed better correlation with ozone variations than precipitation differences, indicating that the photochemical ozone generation variations is more dominant by cloud fraction than wet removal process for high and long-ranged transported ozone cases over Northeast Asia.