• Title/Summary/Keyword: Statistical power

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Verification of the Correlation between Progression-free Survival and Overall Survival Considering Magnitudes of Survival Post-progression in the Treatment of Four Types of Cancer

  • Liu, Li-Ya;Yu, Hao;Bai, Jian-Ling;Zeng, Ping;Miao, Dan-Dan;Chen, Feng
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.3
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    • pp.1001-1006
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    • 2015
  • Background: With development and application of new and effective anti-cancer drugs, the median survival post-progression (SPP) is often prolonged, and the role of the median SPP on surrogacy performance should be considered. To evaluate the impact of the median SPP on the correlation between progression-free survival (PFS) and overall survival (OS), we performed simulations for treatment of four types of cancer, advanced gastric cancer (AGC), metastatic colorectal cancer (MCC), glioblastoma (GBM), and advanced non-small-cell lung cancer (ANSCLC). Materials and Methods: The effects of the median SPP on the statistical properties of OS and the correlation between PFS and OS were assessed. Further, comparisons were made between the surrogacy performance based on real data from meta-analyses and simulation results with similar scenarios. Results: The probability of a significant gain in OS and HR for OS was decreased by an increase of the SPP/OS ratio or by a decrease of observed treatment benefit for PFS. Similarly, for each of the four types of cancer, the correlation between PFS and OS was reduced as the median SPP increased from 2 to 12 months. Except for ANSCLC, for which the median SPP was equal to the true value, the simulated correlation between PFS and OS was consistent with the values derived from meta-analyses for the other three kinds of cancer. Further, for these three types of cancer, when the median SPP was controlled at a designated level (i.e., < 4 months for AGC, < 12 months for MCC, and <6 months for GBM), the correlation between PFS and OS was strong; and the power of OS reached 34.9% at the minimum. Conclusions: PFS is an acceptable surrogate endpoint for OS under the condition of controlling SPPs for AGC, MCC, and GBM at their limit levels; a similar conclusion cannot be made for ANSCLC.

Empirical Study for the Adoption Attitudes of New Product between Generations and Countries -Focused on Korean and Chinese Consumers- (세대 간 및 국가 간 차이에 따른 신제품 수용태도에 대한 실증 연구 -한국과 중국 소비자를 중심으로-)

  • Seo, Yong-Mo;Kim, Hyung-Jun
    • The Journal of the Korea Contents Association
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    • v.11 no.10
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    • pp.405-415
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    • 2011
  • The primary purpose of this paper is to identify the influencing factors on the new products adoption between countries and generations. For this purpose, a research is developed based on the relevant literature reviews. Data have been collected from 524 persons and were tested by t-test and various statistical methods. The results of this empirical study are summarized as follows. In the cultural factors, the groupism has high discretion in China old generation. The materialism and shopping preference have high discretion in two young generations. There is no difference between the two groups in the distance of power. In innovativeness of personality, Korea and China young generation have high discretion. Innovativeness has high discretion in Korea and China youngs. Cognition and sensory innovativeness are has low discretion in Korea old. In the social risk perception, physiological, functional general and financial risk has high discretion in China old. In risk reducing behavior, the normative taking level and ad, new product adoption has high discretion in Korea and China youngs. But, the influence of others has high discretion in China old generation. The safety and brand reputation are no influences. The findings have a several marketing strategies in generation and countries.

A Study on the Optimization of Anti-Jamming Trash Screen with Rake using by Response Surface Method (반응표면분석법을 이용한 제진기의 목메임 방지 개선 및 레이크 최적화)

  • Seon, Sang-Won;Yi, Won;Hong, Seok-Beom
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.3
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    • pp.230-236
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    • 2020
  • A trash screen is installed in front of the inflow channel of a drainage pumping station, sewage treatment plant, and a power plant to block floating contaminants. The bottleneck phenomenon, which decreases the water inflow, causes damage to the damper as a result of clogging in between the screen if string type obstacles are not removed. In this paper, the apron was removed, and the screen was expanded, to prevent breakage of the bottleneck phenomenon and string type obstacles. This was designed using an extended rake by adding an inner rake in between the screen interspace to remove the bottleneck phenomenon and string type obstacles. To design the inner rake that satisfies the allowable stresses of the existing damper rake, the experiment points were determined according to the experimental design method using the inner rake vertical length and the thickness of the reinforced section as parameters. The use of the ANSYS static structural module and statistical analysis tool R software gives the optimized shape according to the response surface method. The relative error between the response surface analysis results and the simulation results was 1.63% of the determined optimal design-point rake length of 210.2 mm and the reinforcement section thickness of 2 mm. Through empirical experiments, a test rake was constructed to the actual size, and approximately 97% of the bottleneck phenomenon and string type obstacles could be removed.

A Development of Real-time Vibration Monitoring and Analysis System Linked to the Integrated Management System of Ministry of Public Safety and Security (국민안전처 통합관리시스템 연계 가능한 시설물 진동 감지 및 분석 시스템 개발)

  • Lim, Ji-Hoon;Jung, Jin-Woo;Moon, Dae-Joong;Choi, Dong-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.3
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    • pp.130-139
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    • 2016
  • A frequency of earthquake occurrence in the Republic of Korea is increasing over the past few decades. In this situation, an importance of earthquake prevention comes to the fore because the earthquake does damage to structures and causes severe damage of human life. For the earthquake prevention, a real-time vibration measurement for structures is important. As an example, the United States of America and Japan have already been monitoring real-time earthquake acceleration for the important structures and the measured acceleration data has been managed by forming database. This database could be used for revising the seismic design specifications or predicting the damage caused by earthquake. In Korea, Earthquake Recovery Plans Act and Enforcement Regulations are revised and declared lately. Ministry of Public Safety and Security is constructing a integrated management system for the measured earthquake acceleration data. The purpose of this research is to develop a real-time vibration monitoring and analysis system for structures which links to the integrated management system. The developed system contains not only a monitoring function to show real-time acceleration data but also an analysis system to perform fast fourier transform, to obtain natural frequency and earthquake magnitude, to show response spectrum and power spectrum, and to evaluate structural health. Additionally, this system is designed to be able to link to the integrated management system of Ministry of Public Safety and Security. It is concluded that the developed system can be useful to build a safety management network, minimize maintenance cost of structures, and prevention of the structural damage due to earthquake.

The Effect of Environment-friendly Certifications on Agricultural Producer Organizations (친환경·GAP·HACCP이 농업 생산자조직에 미치는 영향)

  • Kim, Chang-Hwan;Park, Seong-Ho
    • Journal of Distribution Science
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    • v.13 no.6
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    • pp.97-104
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    • 2015
  • Purpose - The distribution of agricultural products is changing due to recent shifts in environmental free trade. Specifically, the competitiveness of domestic agricultural products has weakened as a result of the Korea-China Financial Trade Agreement. Agricultural producers are faced with increasing difficulties and organized production centers are growing in importance daily. To overcome this crisis, agricultural producer organizations are vying for environment-friendly agricultural certifications, Good Agriculture Practices (GAP) and Hazard Analysis and Critical Control Point (HACCP). In particular, as consumer demand for higher safety grows, farmers are increasing their certification rates. Therefore, this certification system is expected to help strengthen the competitiveness of agricultural producer organizations. Research design/data/methodology - Organized production centers are classified by certification. A survey was conducted with 91 organizations using factor analysis and logistic regression analysis for the examination. The factor analysis results are as follows. Raw material procurement, education·specialization, marketing, joint business, organizing ability, business management, effectiveness, certification, and larger organizations were classified as the nine types of factors. These factors affect the organized production centers and are used in the logistic regression analysis. The purpose of such research and analysis is to suggest a direction for future production center policies. Results - The basic statistical results are as follows: analysis of the producer organizations of 91 sites, average number of members per site of 1,624, and average sales of 25,961 million won. Additionally, the average income per farmer is 175 million won, and the pooling system rate is 53.5%. The factor analysis results are as follows. Factor 1 consists of contract cultivation, ongoing shipment, selection subdivision, traceability, and major retailer management. Factor 2 consists of manual cultivation, specialty selection, education program, and R&D. Factor 3 consists of advertising, various dealers, various sales strategies, and a unified sales counter. Factor 4 consists of agricultural materials co-purchase, policy support, co-shipment, and incentives. Factor 5 consists of the co-selection and pooling system. Factor 6 consists of co-branding and operating by the organization's article. Factor 7 consists of the buy-sell ratio and rate of operation of the agriculture promotion center. Factor 8 consists of bargaining power in volume and participation rate of farmer certification. Factor 9 consists of increasing new subscribers. The logistic regression analysis results are as follows. Considering the results by type of certification, the environment-friendly agricultural certification type and the GAP certification type have a (+) influence. GAP and HACCP certification types affecting the education·specialization factor have a (+) influence. Considering the results for each type of certification, the environment-friendly agricultural certification types on the effectiveness factor have (-) influence; the HACCP certification types on the organizing ability and effectiveness factor have a (-) influence. Conclusions - Agricultural producer organizations should develop plans as follows: The organizations need to secure education for agricultural production; increase the pooling system ratio for sustainable organizational development; and, finally, expand the number of agricultural producer organizations.

A Study on Consumer's Evaluations on and Preferences for Formative images of Products (제품디자인을 위한 조형 이미지의 평가와 선호에 관한 연구)

  • 김관배
    • Archives of design research
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    • v.13 no.1
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    • pp.167-178
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    • 2000
  • Today's world has been changing form post-industrial society to information society, and criteria of human value, also, has been changing from physical to intellectual and sensible. Based on this trend, intellectual and sensible value of a product is becoming more important in comsumer's market than physical value. The environment of product design has been rapidly changing. Users and consumers pursuit sensible satisfaction through their lives based on images of products. As the environment in which a product is used has been more important, companies have placed more emphasis on consumers and users, and are trying to satisfy their consumers by developing products with emphasis on their design, as well as to develop human technology. In ever-changing environment, a question is if sensible design can be developed in product design. Companies could upgrade their competitive power and brand image only if they could develope designs which could satisfy consumers through sensible design approach with a base on systematic research on h~man sensibility. In this context, the purpose of this study was to: investigate consumer's evaluations on and preferences for formative images of products according to the types of human sensibility. This research study placed emphasis on quantitative analysis of consumers' emotional needs to find out consumer's evaluations on and preferences for formative images of products. The researcher reviewed related literature on human sensibility and design, as well as G-Kansei and product design. Data were collected through a questionnaire and analyzed through a statistical program, and highly effective design strategy was investigated through analysis of data and interpretation of the results.

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Biochemical changes and drug residues in ascidian Halocynthia roretzi after formalin-hydrogen peroxide treatment regimen designed against soft tunic syndrome

  • Lee, Ji-Hoon;Kim, Ju-Wan;Shin, Yun-Kyung;Park, Kyung-Il;Park, Kwan Ha
    • Fisheries and Aquatic Sciences
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    • v.20 no.7
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    • pp.12.1-12.7
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    • 2017
  • Soft tunic syndrome (STS) is a protozoal disease caused by Azumiobodo hoyamushi in the edible ascidian Halocynthia roretzi. Previous studies have proven that combined formalin-hydrogen peroxide ($H_2O_2$) bath is effective in reducing STS progress and mortality. To secure target animal safety for field applications, toxicity of the treatment needs to be evaluated. Healthy ascidians were bathed for 1 week, 1 h a day at various bathing concentrations. Bathing with 5- and 10-fold optimum concentration caused 100% mortality of ascidians, whereas mortality by 0.5- to 2.0-fold solutions was not different from that of control. Of the oxidative damage parameters, MDA levels did not change after 0.5- and 1.0-fold bathing. However, free radical scavenging ability and reducing power were significantly decreased even with the lower-than-optimal 0.5-fold concentration. Glycogen content tended to increase with 1-fold bathing without statistical significance. All changes induced by the 2-fold bathing were completely or partially restored to control levels 48 h post-bathing. Free amino acid analysis revealed a concentration-dependent decline in aspartic acid and cysteine levels. In contrast, alanine and valine levels increased after the 2-fold bath treatment. These data indicate that the currently established effective disinfectant regimen against the parasitic pathogen is generally safe, and the biochemical changes observed are transient, lasting approximately 48 h at most. Low levels of formalin and $H_2O_2$ were detectable 1 h post-bathing; however, the compounds were completely undetectable after 48 h of bathing. Formalin-$H_2O_2$ bathing is effective against STS; however, reasonable care is required in the treatment to avoid unwanted toxicity. Drug residues do not present a concern for consumer safety.

Effect of field location and spray device on pesticide residue in chilli peppers (농약 살포조건이 고추열매 중 잔류에 미치는 영향)

  • Son, Kyeong-Ae;Kang, Tae-Kyeong;Park, Byeong-Jun;Kim, Taek-Kyum;Gil, Geun-Hwan;Kim, Chan-Sub;Kim, Jin-Bae;Im, Geon-Jae;Lee, Key-Woon
    • The Korean Journal of Pesticide Science
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    • v.16 no.3
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    • pp.230-235
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    • 2012
  • This study was carried out to clarify effects of field location and sprayer on the level of pesticide residue in chilli peppers. As confirmed by statistical analysis, the residue levels in green pepper among three greenhouses did not show significant difference at the first day after spraying with the same engine sprayer and nozzle. But the residue levels in green peppers collected from the exposed outside of crop were 2 times higher than those from the hidden inside. The sampling site was one of variation elements of pesticide residue. The residue levels after application by knapsack engine powered sprayer were 1.7 times higher than those by manual compressed sprayer. As the spraying pressure of the engine power sprayer is 2 times higher than the commonly used pressure of the manual compressed sprayer, the pressure of the sprayer and nozzles were considered to affect on the residue levels in peppers.

Comparing Survival Functions with Doubly Interval-Censored Data: An Application to Diabetes Surveyed by Korean Cancer Prevention Study (이중구간중도절단된 생존자료의 생존함수 비교를 위한 검정: 한국인 암 예방연구 중 당뇨병에의 응용)

  • Jee, Sun-Ha;Nam, Chung-Mo;Kim, Jin-Heum
    • The Korean Journal of Applied Statistics
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    • v.22 no.3
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    • pp.595-606
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    • 2009
  • Two tests were introduced for comparing several survival functions with doubly interval-censored data and illustrated with data surveyed by Korean Cancer Prevention Study (Jee et al., 2005). The test which extended Kim et al. (2006)'s test to the doubly interval-censored data has an advantage over Sun (2006)'s test in terms of saving computation time because the proposed test only depends on the size of risk set, and also the proposed test is applicable to continuous failure time data as well as discrete failure time data unlike Sun's test. Comparing male with female groups on the incubation time of diabetes was highly different and the survival of female group was longer than that of male one. Regardless of gender, the difference in survival functions of four age groups was highly significant with p-value of less than 0.001. This trend was more remarkable for female group than for male one. Simulation results showed that the significance level of both tests was well controlled and the proposed test was better than Sun's test in terms of power.

Effect of Naeso-san on Gastric Motility between Normal Intact and Antral Dilatated Rats (내소산(內消散)의 정상 및 위 유문부 확장 흰 쥐의 위 운동성에 대한 효능)

  • Kim, Jin-Seok;Yoon, Sang-Hyub
    • The Journal of Internal Korean Medicine
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    • v.29 no.1
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    • pp.117-129
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    • 2008
  • Background & Objective : Naeso-san(NSS) has been used for the treatment of functional dyspepsia, regarded as a gastric dysmotility disease. A main cause of gastric dysmotility is antral dilatation or antroduodenal uncoordination. Therefore, we investigated the effect of NSS on gastric motility and its mechanism of action, as well as the morphologic changes in antral dilatated rats. Methods : Antral dilatated rats were induced by wrapping a nonabsorbable rubber ring(D:6mm, W:4mm, T:1mm) around the 1st portion of the duodenum for 8 weeks. Then morphologic changes were investigated and compared with normal intact rats before and after 8 weeks. Gastric emptying was measured by administration of normal saline(NS) or NSS in normal intact and antral dilatated rats. In another series of experiments to evaluate the mechanism of NSS under delayed conditions, normal intact rats were treated with atropine sulfate(1mg/kg, s.c.), quinpirole HCl(0.3mg/kg, i.p.), $NAME(N^{G}-nitro-L-arginine$ methyl ester, 75mg/kg, s.c.) and cisplatin(10mg/kg, i.p.), respectively. The myoelectrical activity of the gastric smooth muscle was recorded in normal intact and antral dilatated rats. The contractile waves were measured for 30 minutes before and after administration of each solution(NS, NSS). Results : Body weight gain of antral dilatated rats was significantly lower than that of the controls. Futhermore, we found the thickness of the mucosal and muscular layers and surface area of the stomach increased significantly compared with controls. NSS 278㎎/㎏ improved gastric emptying more than normal saline or NSS 93mg/kg in normal intact(p=0.026) and antral dilatated rats(p=0.03). NSS enhanced gastric emptying significantly in the NAME treated group(p=0.002). NSS 278mg/kg increased the significant postprandial dominant power than that of NS in normal intact rats, whereas there was no statistical significance in antral dilatated rats. Conclusions : NSS stimulates gastric motility through the cholinergic pathway. We expect that pathologic model with antral dilatation can be used as an exprimental tool which is similar to dyspepsia and NSS would be effective especially in dysmotility-like functional dyspepsia with antral dilatation or impaired reservoir functions such as gastric adaptive relaxation.

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