• Title/Summary/Keyword: Termination criteria

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Trends in reproductive health-related research on women in Korea: A systematic review of published studies since 1995 (여성의 생식건강에 관한 국내 연구동향 : 1995년 이후 연구에 대한 고찰)

  • Lee, Young-Ran;Chu, Min Sun
    • Journal of Home Health Care Nursing
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    • v.22 no.2
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    • pp.237-245
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    • 2015
  • Purpose: The purpose of this study was to investigate the research methods, topics and trend in reproductive health on women in Korea. Method: We reviewed 102 studies from the electronic database of KISS, RISS, NDSL, and PubMed, and finally selected 13 studies based on relevant criteria. Result: With regard to research methods, the majority of studies used survey research. As for the research themes, reproductive health status was most common. For study results, knowledge status of pregnancy and contraception were higher in university students. High school female students' level of sexual awareness was higher than that of male students. Around 30% of college students experienced direct sexual behavior. Ten percent of college students who had sexual experience had an unplanned pregnancy. About half of married women had experienced artificial termination of pregnancy at least once. Conclusion: The results of this study provide a basis for the improvement of women's reproductive health.

Sequential Approximate Optimization Using Kriging Metamodels (크리깅 모델을 이용한 순차적 근사최적화)

  • Shin Yongshik;Lee Yongbin;Ryu Je-Seon;Choi Dong-Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.9 s.240
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    • pp.1199-1208
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    • 2005
  • Nowadays, it is performed actively to optimize by using an approximate model. This is called the approximate optimization. In addition, the sequential approximate optimization (SAO) is the repetitive method to find an optimum by considering the convergence of an approximate optimum. In some recent studies, it is proposed to increase the fidelity of approximate models by applying the sequential sampling. However, because the accuracy and efficiency of an approximate model is directly connected with the design area and the termination criteria are not clear, sequential sampling method has the disadvantages that could support an unreasonable approximate optimum. In this study, the SAO is executed by using trust region, Kriging model and Optimal Latin Hypercube design (OLHD). Trust region is used to guarantee the convergence and Kriging model and OLHD are suitable for computer experiment. finally, this SAO method is applied to various optimization problems of highly nonlinear mathematical functions. As a result, each approximate optimum is acquired and the accuracy and efficiency of this method is verified by comparing with the result by established method.

Multidisciplinary Design Optimization Based on Independent Subspaces with Common Design Variables (공통설계변수를 고려한 독립적하부시스템에 의한 다분야통합최적설계)

  • Shin, Jung-Kyu;Park, Gyung-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.3 s.258
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    • pp.355-364
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    • 2007
  • Multidisciplinary design optimization based on independent subspaces (MDOIS) is a simple and practical method that can be applied to the practical engineering MDO problems. However, the current version of MDOIS does not handle the common design variables. A new version of MDOIS is proposed and named as MDOIS/2006. It is a two-level MDO method while the original MDOIS is a single-level method. At first, system analysis is performed to solve the coupling in the analysis. If the termination criteria are not satisfied, each discipline solves its own design problem. Each discipline in the lower level solves the problem with common design variables while they are constrained by equality constraints. In the upper level, the common design variables of related disciplines are determined by using the optimum sensitivity of the objective function. To validate MDOIS/2006, mathematical problem and NASA test bed problem are solved. The results are compared with those from other MDO methods. Finally, MDOIS/2006 is applied to flow patterner design and shows that it can be successfully applied to the practical engineering MDO problem.

Mathematical Proof for Structural Optimization with Equivalent Static Loads Transformed from Dynamic Loads (동하중에서 변환된 등가정하중에 의한 최적화 방법의 수학적 고찰)

  • Park, Gyung-Jin;Kang, Byung-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.2
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    • pp.268-275
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    • 2003
  • Generally, structural optimization is carried out based on external static loads. All forces have dynamic characteristics in the real world. Mathematical optimization with dynamic loads is extremely difficult in a large-scale problem due to the behaviors in the time domain. The dynamic loads are often transformed into static loads by dynamic factors, design codes, and etc. Therefore, the optimization results can give inaccurate solutions. Recently, a systematic transformation has been proposed as an engineering algorithm. Equivalent static loads are made to generate the same displacement field as the one from dynamic loads at each time step of dynamic analysis. Thus, many load cases are used as the multiple leading conditions which are not costly to include in modern structural optimization. In this research, it is mathematically proved that the solution of the algorithm satisfies the Karush-Kuhn-Tucker necessary condition. At first, the solution of the new algorithm is mathematically obtained. Using the termination criteria, it is proved that the solution satisfies the Karush-Kuhn-Tucker necessary condition of the original dynamic response optimization problem. The application of the algorithm is discussed.

A Study on Thermo-Hydraulic Analysis for KSTAR(Korea Superconducting Tokamak Advanced Research) Cooling Line System (KSTAR(Korea Superconducting Tokamak Advanced Research) 냉각 시스템에 대한 열해석 연구)

  • Kim, H.W.;Ha, J.S.;Kim, D.S.;Lee, J.S.;Choi, C.H.
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.296-301
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    • 2003
  • A study on the engineering design and numerical thermo-hydraulic analysis for KSTAR TF coil structure cooling system has been conducted. The numerical analyses have been done to verify the engineering design of cooling using the commercial code, FLUENT and in-house code for calculating helium properties which varies with cooling tube's heat transfer. Through the engineering design process based on the steady heat balance concepts, the circular stainless steel tube with inner diameter of 4 mm for TF coil has been selected as cooling tube. From normal operation mode analysis results, total 28 cooling tubes were finally chosen. Also, three dimensional cool down analysis for TF coil with designed cooling tube was satisfied with next three design criteria. First is cooling work termination within a month, second is maximum temperature difference within 50 K in TF coil structure and third is exit helium pressure above 2 bar. Consequently, these cool down scenario results can afford to adopt as operating scenario data when KSTAR facilities operate.

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Study of Gradual restriction method of water supply to termination criteria at each drought response stage (가뭄대응 단계별 점진적 용수제한공급 방안 연구)

  • Park, Jin Hyeog;Jang, Suhyung;Kim, Jung Min;Kang, Hyun woong;Son, Chanyoung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.377-377
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    • 2018
  • 2016년 6월 국토교통부에서는 강수량의 부족으로 인한 다목적댐 용수공급 중단 피해를 최소화하기 위해 "댐 용수부족 대비 용수공급 조정기준"을 시행하였다. 다목적댐에서 가뭄에 사전 대응하기 위해 기준저수량을 설정하고 이 기준저수량에 따라 4단계의 가뭄단계로 구분된다. 댐 저수량이 가뭄 단계별 기준저수량 이하로 저하될 경우, 가뭄단계 발령 및 용수제한공급이 시행되는데 하천유지용수, 농업용수, 생 공용수 순으로 감량이 이루어진다. 하지만 급격한 용수제한공급으로 인한 피해가 우려된다. 따라서 본 연구에서는 가뭄시 효율적인 용수공급을 위해 낙동강유역의 합천댐 유역을 대상으로 저수량이 부족한 댐 준공당시와 과거 대표적인 가뭄기간(1994-1997년, 2009-2010년)에 대하여 정상환원, 관심, 주의, 경계 그리고 심각 총 5단계의 용수제한공급 단계를 10계로 세분화하고 6가지의 용수공급 시나리오를 설정하여 그 효과를 분석하였다. 시나리오에 따라 최악의 경우 생 공용수 50%를 감량함으로서 기존 기준보다 신속하게 저수량을 정상단계로 회복시켜주는 효과를 보였다.

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The quality control and acceptability of spirometry in preschool children (학동 전기 소아에서 폐활량 측정의 질관리와 성공률)

  • Seo, Hyun Kyong;Chang, Sun Jung;Jung, Da Woon;Lee, Cho Ae;Wee, Young Sun;Jee, Hye Mi;Seo, Ji Young;Han, Man Yong
    • Clinical and Experimental Pediatrics
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    • v.52 no.11
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    • pp.1267-1272
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    • 2009
  • Purpose:We examined the ability of preschool aged children to meet the American Thoracic Society (ATS) and European Resiratory Society (ERS) goals for spirometry quality and tried to find out the major factor for improving the rate of success of spiromety test in this age group. Methods:Spirometry was performed in 2-6 aged 155 children with chronic cough or suspicious asthma with the recording of maneuver quality measures of forced expiratory time, end-of-test volume, back-extrapolated volume (Vbe), and forced vital capacity (FVC), as well as flow-volume curve. The subjects were tested several times and the two best results in each subject were selected. All criteria for quality control were suggested by ATS/ERS guidelines. The criteria for starting of the test was Vbe <80 mL and Vbe/FVC <12.5%. The criteria for repeatability of the test was that second highest FVC and FEV1 are within 100 ml or 10% of the highest value, whichever is greater. For the criteria for termination of the test for preschool aged children, we evaluated the flow-volume curve Results:As getting older, the success rate of spirometry increased and rapidly increased after 3 years old. Total success rate of the test was 59.4% (2 years old - 14.3%, 3 years old - 53.7%, 4 years old - 65.1%, 5 years old - 69.7%, 6 years old- 70.8%). The percentage of failure to meet the criteria for starting the test was 6.5%, repeatability of the test was 12.3% and end of the test was 31%. There was a significant difference only in age between success group and failure group. Evaluating the quality control criteria of previous studies, the success rate increased with age. Conclusion:About 60% of preschool aged children met ATS/ERS goals for spirometry test performance and the success rate was highly correlated with age. It is clearly needed that developing more feasible and suitable criteria for quality control of spirometry test in preschool aged children.

Effect of Day Length and Temperature on the Diapause Termination of Riptortus pedestris (Hemiptera: Alydidae) Male Adults (일장과 온도 처리가 톱다리개미허리노린재 수컷 성충의 휴면종료에 미치는 영향)

  • Huh, Wan;Park, Chung-Gyoo
    • Korean journal of applied entomology
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    • v.49 no.3
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    • pp.205-210
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    • 2010
  • The bean bug, Riptortus pedestris (=clavatus) Fabricius (Hemiptera: Alydidae) is a serious pest of soybean in many countries. It enters a reproductive diapause in the winter by short day length (<13.5 h.) in Korea and Japan. The combined effects of temperatures ($25^{\circ}C$ and $8^{\circ}C$) and day lengths (10L:14D and 14L:10D) upon the termination of the male's diapause were studied. The combinations are (1) HTLD = $25^{\circ}C$, 14L:10D treatment for 1, 2, 3 weeks and 30 days; (2) HTSD = $25^{\circ}C$, 10L:14D treatment for 1, 2, and 3 weeks; (3) LTLD$\rightarrow$HTLD = $8^{\circ}C$, 14L:10D treatment for 1, 2, and 3 weeks followed by HTLD treatment; (4) LTSD$\rightarrow$HTLD = $8^{\circ}C$, 10L:14D treatment for 1, 2, and 3 weeks followed by HTLD. The amount of aggregation pheromone components secreted was adopted as the criteria for diapause termination in males. Males did not secrete aggregation pheromone under HTSD conditions. However, the males treated with HTLD for more than 21 days secreted significantly higher amounts of aggregation components, (E)-2-hexenyl (Z)-3-hexenoate and (E)-2-hexenyl (E)-2-hexenoate, compared to the control or HTSD treatments. The three components of the aggregation pheromone were secreted by the 14%, 29%, and 100% males treated with HTLD for 7 days, respectively. However more than 83% of the HTLD-treated males secreted all three components by the $30^{th}$ day under the treatment. In comparison, the pheromone amounts secreted by the males treated with LTLD$\rightarrow$HTLD or LTSD$\rightarrow$HTLD were equal or less than those secreted by males with continuous HTLD treatment.

Transcallosal Ipsilateral Motor Pathway from the Unaffected Hemisphere in a Patient with Traumatic Brain Injury

  • Jang, Woo-Hyuk;Lee, Mi-Young;Kwon, Yong-Hyun;Jang, Sung-Ho
    • The Journal of Korean Physical Therapy
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    • v.26 no.3
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    • pp.216-219
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    • 2014
  • Purpose: We presented with a patient with traumatic brain injury who showed a transcallosal ipsilateral motor pathway from unaffected motor cortex to affected extremities, as evaluated by diffusion tensor tractography (DTT). Methods: One patient and six age-matched normal subjects were enrolled. A 42-year-old left hemiparetic male who suffered from brain injury by motor vehicle accident 9 years ago showed a leukomalactic lesion in the right corona radiata and parieto-temporal lobe. His left extremities were completely paralyzed initially, but recovered slowly over 2 years. At the time of the evaluation, he was able to grasp and release an object, and to walk with spastic gait pattern. DTT was performed using 1.5 T with a Synergy-L Sensitivity Encoding head coil. DTT was obtained with termination criteria of FA <0.2 and an angle change > $45^{\circ}c$. Results: The motor tracts of the unaffected (left) hemisphere of the patient and control subjects originated from the motor cortex and descended along the known corticospinal tract without any transcallosal tract. By contrast, the tract of the affected (right) hemisphere originated from the left premotor cortex, descended through the left corona radiata, and then crossed the mid-portion of the corpus callosum. The tract then descended through the known corticospinal tract pathway to the right medulla. Conclusion: We conclude that the transcallosal ipsilateral motor pathway from the unaffected hemisphere appeared to contribute to the motor recovery in this patient.

A Study on Integrated Production Planning of Distributed Manufacturing Systems on Supply Chain (공급사슬상의 분산 제조 시스템의 통합생산계획에 관한 연구)

  • Koh, Do-Sung;Yang, Yeong-Cheol;Jang, Yang-Ja;Park, Jin-Woo
    • IE interfaces
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    • v.13 no.3
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    • pp.378-387
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    • 2000
  • As the globalization of manufacturing companies continues, the scope of dependence between these companies and distributors, and other suppliers are growing very rapidly since no one company manufactures or distributes the whole product by themselves. And, the need to increase the efficiency of the whole supply chain is increasing. This paper deals with a multi-plant lot-sizing problem(MPLSP) which happens in a decentralized manufacturing system of a supply chain. In this study, we assume that the whole supply chain is driven by a single source of independent demand and many levels of dependent demands among manufacturing systems in the supply chain. We consider setup cost, transportation cost and time, and inventory holding cost as a decision factor in the MPLSP. The MPLSP is decomposed into two sub-problems: a planning problem of the whole supply chain and a lot-sizing problem of each manufacturing system. The supply chain planning problem becomes a pure linear programming problem and a Generalized Goal Decomposition method is used to solve the problem. Its result is used as a goal of the lot-sizing problem. The lot-sizing problem is solved using the CPLEX package, and then the coefficients of the planning problem are updated reflecting the lot-sizing solution. This procedure is repeated until termination criteria are met. The whole solution process is similar to Lagrangian relaxation method in the sense that the solutions are approaching the optimum in a recursive manner. Through experiments, the proposed closed-loop hierarchical planning and traditional hierarchical planning are compared to optimal solution, and it is shown that the proposed method is a very viable alternative for solving production planning problems of decentralized manufacturing systems and in other areas.

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