• Title/Summary/Keyword: Statistical design

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Research Trends of Oriental Medicine in Korea and Meta-analysis of Articles related to Stroke in the Journal of Korean Oriental Medicine (한의학회지의 뇌졸중 관련논문을 통한 한의학 연구동향과 질적 메타분석)

  • Ko, Seong-Gyu
    • The Journal of Internal Korean Medicine
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    • v.22 no.2
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    • pp.223-237
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    • 2001
  • Objective : There have not been studies on the oriental medicine research trends and qualitative analysis of Korean oriental medicine articles in Korea, particularly in the oriental medicine area. This study's purpose is to appreciate Korean oriental medicine's research trends and assess the quality of the Korean oriental medical journals' level. This study will help upgrade Korean oriental medical journals. Method : We found 93 stroke-related articles in the Journal of Korean Oriental Medicine, published between 1980(Volume 1) and 2001(Volume 45). We surveyed the institutes involved in each study, and the number of people in each study. We seperated by epidemiological study design, the studies into categories. Campbell and Stanley's study design into 6 categories, statistical methods into 13 categories. Next, we assessed the 41 articles by a checklist, which had 10 categories. The quality score was analyzed by survey variables over the period, which were divided by the date of publication: the 1980s, the first half of the 1990s, second half of the 1990s and 2000s. Results : 46.3% od the studies didn't use statistical methods. 56.1%, were case series studies by classification of epidemiological study design, and 53.6% were one-shot case studies designed by Campbell and Stanley's study design. The quality score was 58.33 point 60 is average. In quality level by Browman GP etc.'s, 83.0% of the studies were included in V levels. But, the quality scores were significant by presence of reviewer system, statistical method's usage, and over the period. Conclusion : The Journal of Korean Oriental Medicine needs to improve the quality its articles. To improve the quality of oriental medicine related articles, the following are necessary: working together, joint work of inter-educational system, strengthening of reviewer system, use of statistical methods, and consulting to the expert of research at the stage of study design.

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Analysis on Application of Limit State Design Method for Bridge Evaluation Considering PSC Beam Bridge Experiment Results (PSC Beam교의 실측실험을 반영한 한계상태설계법 기반 교량 평가법 적용 분석)

  • Kim, Kyunghyun;Yoo, Minsun;Paik, Inyeol;Shin, Soobong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.6
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    • pp.235-244
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    • 2021
  • This study analyzes the applicability of limit state design method on bridge evaluation by considering the experiment of the existing bridge. The test strength of the member is obtained from the PSC beam bridge experiment. The test strength is compared with the calculated strength obtained from the statistical characteristics of material test strength and the two values are almost the same. The response modification factor and dynamic impact factor are obtained from the vehicle loading test. The rating factor is calculated by applying limit state design method as well as current evaluation method and the results are compared. The reliability index of the test bridge is calculated by using the statistical properties of the member strength obtained from material test and simulation. When the statistical properties of the PSC beam tested in this study are applied, the reliability index with a larger value was obtained than the reliability index obtained with the statistical properties of the design code.

A Development of the Ship Weight Estimating Method by a Statistical Approach (통계적 접근법에 의한 선박 중량추정 방법 개발)

  • Cho, Yong-Jin
    • Journal of the Society of Naval Architects of Korea
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    • v.48 no.5
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    • pp.426-434
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    • 2011
  • Accurate weight prediction methods are an essential of the ship design in both ship cost managements and performance satisfactions. When no parent or similar ships are available, an adequate method of the ship weight estimating is required. In this study, there was carried out to develop the ship weight estimating method for the preliminary design phase. The weight estimating methods were first surveyed by the references and summarized their characteristics. The weight estimation method by statistical approach was developed for the container ship because the containerized transportation markets is gradually growing and ship's size and loading capacity are rapidly enlarged. The correlation analysis and the multiple regression analysis were used for developing the weight estimating method. As a results of evaluating the developed method, the error ratio of the variation between estimated weight and ship's data was about 5%. And it was only 1% difference with the calculating weight of conceptual design results by shipyard design team that the estimating weight of ultra-large container ship was predicted by the developed method.

Statistical Optimization of Medium Components for the Production of Prodigiosin by Hahella chejuensis KCTC 2396

  • Kim, Sung-Jin;Lee, Hong-Kum;Yim, Joung-Han
    • Journal of Microbiology and Biotechnology
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    • v.18 no.12
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    • pp.1903-1907
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    • 2008
  • Prodigiosin is a natural red pigment with algicidal activity against Cochlodinium polykrikoides, a major harmful red-tide microalga. To increase the yield of prodigiosin production by Hahella chejuensis KCTC 2396, significant medium components were determined using a two-level Plackett-Burman statistical design technique. Among 12 components included in basal medium, $NaHCO_3$, ${Na}_{2}{SiO}_{3}$, ${NH_4}{NO_3}$, ${Na}_{2}{SO}_{4}$ and $CaCl_2$ were determined to be important for prodigiosin production. The medium formulation was finally optimized using a Box-Behnken design as follows: 1% sucrose; 0.4% peptone; 0.1 % yeast extract; and (g/l): NaCl, 20.0; ${Na}_{2}{SO}_{4}$, 9.0; $CaCl_2$, 1.71; KCl, 0.4; and (mg/l): ${H_3}{BO_3}$, 10.0; KBr, 50.0; NaF, 2.0; $NaHCO_3$, 45.0; ${Na}_{2}{SiO}_{3}$, 4.5; ${NH_4}{NO_3}$, 4.5. The predicted maximum yield of prodigiosin in the optimized medium was 1.198 g/l by the Box-Behnken design, whereas the practical production was 1.495 g/l, which was three times higher than the basal medium (0.492 g/l).

State of the Art of Segment Lining in Shield Tunnel and Statistical Analysis of Its Key Design Parameters (쉴드터널 세그먼트 라이닝의 최신 기술동향과 핵심 설계항목의 통계 분석)

  • Chang, Soo-Ho;Lee, Gyu-Phil;Choi, Soon-Wook;Bae, Gyu-Jin
    • Tunnel and Underground Space
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    • v.21 no.6
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    • pp.427-438
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    • 2011
  • Segment lining is a key permanent lining structure to maintain the shield tunnel stability in shield tunnel operation. Moreover, segment lining generally accounts for the largest proportion in the shield tunnel construction costs. As a result, technical improvements to increase its economic feasibility have been actively carried out. This study aims to propose the development directions of high-performance segments from their recent cutting technologies. In addition, based on over 2,100 world-widely collected segment design data, a series of statistical analyses of segment key design parameters such as thickness, width and the number of divisions as well as segment materials were carried out to approximately estimate them in a design stage.

A Study on the Statistical Model Validation using Response-adaptive Experimental Design (반응적응 시험설계법을 이용하는 통계적 해석모델 검증 기법 연구)

  • Jung, Byung Chang;Huh, Young-Chul;Moon, Seok-Jun;Kim, Young Joong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.347-349
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    • 2014
  • Model verification and validation (V&V) is a current research topic to build computational models with high predictive capability by addressing the general concepts, processes and statistical techniques. The hypothesis test for validity check is one of the model validation techniques and gives a guideline to evaluate the validity of a computational model when limited experimental data only exist due to restricted test resources (e.g., time and budget). The hypothesis test for validity check mainly employ Type I error, the risk of rejecting the valid computational model, for the validity evaluation since quantification of Type II error is not feasible for model validation. However, Type II error, the risk of accepting invalid computational model, should be importantly considered for an engineered products having high risk on predicted results. This paper proposes a technique named as the response-adaptive experimental design to reduce Type II error by adaptively designing experimental conditions for the validation experiment. A tire tread block problem and a numerical example are employed to show the effectiveness of the response-adaptive experimental design for the validity evaluation.

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Evaluating the efficiency of treatment comparison in crossover design by allocating subjects based on ranked auxiliary variable

  • Huang, Yisong;Samawi, Hani M.;Vogel, Robert;Yin, Jingjing;Gato, Worlanyo Eric;Linder, Daniel F.
    • Communications for Statistical Applications and Methods
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    • v.23 no.6
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    • pp.543-553
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    • 2016
  • The validity of statistical inference depends on proper randomization methods. However, even with proper randomization, we can have imbalanced with respect to important characteristics. In this paper, we introduce a method based on ranked auxiliary variables for treatment allocation in crossover designs using Latin squares models. We evaluate the improvement of the efficiency in treatment comparisons using the proposed method. Our simulation study reveals that our proposed method provides a more powerful test compared to simple randomization with the same sample size. The proposed method is illustrated by conducting an experiment to compare two different concentrations of titanium dioxide nanofiber (TDNF) on rats for the purpose of comparing weight gain.

Transmit Precoder Design for Two-User Broadcast Channel with Statistical and Delayed CSIT

  • Sun, Yanjing;Zhou, Shu;Cao, Qi;Wang, Yanfen;Liu, Wen;Zhang, Xiaoguang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.5
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    • pp.2124-2141
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    • 2018
  • Recent studies have revealed the efficacy of incorporating delayed channel state information at transmit side (CSIT) in transmission scheme design. This paper focuses on transmit precoder design to maximize the ergodic sum-rate in a two-user Multiple-Input Single-Output (MISO) system with delayed and statistical CSIT. A new transmit strategy which precodes signals in all transmit slots is proposed in this paper, denoted as all time-slots precoding Alternative MAT (AAMAT). There is a common procedure in conventional delayed-CSIT based schemes, which is retransmitting the overheard interferences. Since the retransmitting signal is intended to both users, all previous schemes tend to use only one antenna. We however figure out an improvement in spectral efficiency could be realized if all antennas can be utilized. In this paper, we detail the design of the procoder which enabling all antennas and also we compute a lower bound of the ergodic sum-rate in an ideal condition. In addition, simulation results demonstrate the superiority of our proposed scheme.

A Study on the Build of a QbD Six Sigma System to Promote Quality Improvement(QbD) Based on Drug Design (의약품 설계 기반 품질 고도화(QbD)를 위한 QbD 6시그마 체계 구축에 관한 연구)

  • Kim, Kang Hee;Kim, Hyun-jung
    • Journal of Korean Society for Quality Management
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    • v.50 no.3
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    • pp.373-386
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    • 2022
  • Purpose: This study proposes the application of Six Sigma management innovation method for more systematically enhanced execution of Quality by Design (QbD) activities. QbD requires a deeper understanding of the product and process at the design and development stage of the drug, and it is very important to ensure that no fault is fundamentally generated through thorough process control. Methods: Analyzing the background and specific procedures of quality improvement based on the drug design basis, and analyzing the key contents of each step, we have differentated and common points from the 6 Sigma methodology. We propose a new model of Six Sigma management innovation method suitable for pharmaceutical industry. Results: Regulatory agencies are demanding results from statistical analysis as a scientific basis in developing medicines to treat human life through quality improvement activities based on drug design. By utilizing the education system to improve the statistical analysis capacity in the Six Sigma activities and operating the 6 Sigma Belt system in conjunction, it helped systematically strengthen the execution power of quality improvement activities based on pharmaceutical design based on the members of the pharmaceutical industry. Conclusion: By using QbD Six Sigma, which combines quality enhancement based on pharmaceutical design basis and Six Sigma methodology suitable for pharmaceutical industry, it is possible to obtain satisfactory results both by pharmaceutical companies and regulators by using appropriate statistical analysis methods for preparing scientific evidence data required by regulatory.

Hybrid Constrained Extrapolation Experimental Design (하이브리드형 제약 외삽실험 계획법)

  • Kim, Young-Il;Jang, Dae-Heung
    • Communications for Statistical Applications and Methods
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    • v.19 no.1
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    • pp.65-75
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    • 2012
  • In setting an experimental design for the prediction outside the experimental region (extrapolation design), it is natural for the experimenter to be very careful about the validity of the model for the design because the experimenter is not certain whether the model can be extended beyond the design region or not. In this paper, a hybrid constrained type approach was adopted in dealing model uncertainty as well as the prediction error using the three basic principles available in literature, maxi-min, constrained, and compound design. Furthermore, the effect of the distance of the extrapolation design point from the design region is investigated. A search algorithm was used because the classical exchange algorithm was found to be complex due to the characteristic of the problem.