• Title/Summary/Keyword: sample selection

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Bioprosthesis in the Mitral Position: Bovine Pericardial versus Porcine Xenograft

  • Han, Dong Youb;Park, Sung Jun;Kim, Ho Jin;Jung, Sung-Ho;Choo, Suk Jung;Chung, Cheol Hyun;Lee, Jae Won;Kim, Joon Bum
    • Journal of Chest Surgery
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    • v.55 no.1
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    • pp.69-76
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    • 2022
  • Background: While the use of bioprosthetic valves for mitral valve replacement (MVR) is increasing, very few studies have compared bovine pericardial and porcine valves in the mitral position to help guide bioprosthetic selection. Methods: In the present study, patients who underwent MVR using bovine pericardial valves were compared with those who underwent MVR with porcine bioprostheses between January 1996 and July 2018. Those with prior MVR, infective endocarditis, congenital mitral valve disease, or ischemic mitral regurgitation were excluded. The primary outcomes were structural valve deterioration (SVD) and mitral valve reoperation from any cause, and death was regarded as a competing risk. Competing risk analysis and propensity score-matching were used for comparisons. Results: Among the 388 patients enrolled, pericardial and porcine bioprostheses were implanted in 217 (55.9%) and 171 (44.1%), respectively. Propensity score-matching yielded 122 pairs of patients that were well-balanced for all baseline covariates. No significant differences were observed between the groups in unadjusted (p=0.09) and adjusted overall survival (hazard ratio [HR], 1.13; 95% confidence interval [CI], 0.72-1.76; p=0.60). Competing risk analysis revealed no significant differences in the risks of mitral reoperation (HR, 1.07; 95% CI, 0.50-2.27; p=0.86) and development of SVD (HR, 1.57; 95% CI, 0.56-4.36; p=0.39) between the groups. Matched population analysis confirmed similar results regarding reoperation (HR, 0.99; 95% CI, 0.40-3.22; p=0.98) and SVD (HR, 1.39; 95% CI, 0.41-4.73; p=0.60). Conclusion: No significant differences in survival or valve durability were observed between bovine pericardial and porcine bioprosthetic MVR. These findings require further validation through studies with larger sample sizes.

The Effect on the Switching Intention to the Blockchain-based Supply Chain Management Information System (블록체인 기반 공급망관리 정보시스템으로의 전환의도에 영향을 미치는 요인)

  • Kyoung Sang Oh;Dong Myung Lee
    • Journal of Industrial Convergence
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    • v.20 no.12
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    • pp.11-25
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    • 2022
  • In this study, we want to verify the factors that affect the intention to switch to a supply chain management information system applied with blockchain. To this end, variable selection and research model were constructed through the review of previous studies, and empirical analysis was conducted using the TOE framework and PPM model. The effects of Push and Pull factors on the intention to switch to the block chain system and the moderating effect through the switching cost which is a Mooring factor, were verified. The hypothesis was verified using a structural equation model using a sample of 320 response data by conducting a questionnaire survey on small and medium-sized enterprises located in Korea. As a result of the study, social influence, which is a push factor, and management's will to innovate, which is a Pull factor, had a significant effect on switching intention. And the moderating effect between the groups with high and low switching cost recognition was confirmed. This study is significant in that it presents the concept and research direction of SCBM (supply chain & blockchain management) that can enhance the competitiveness of a company through the implementation of a blockchain-based supply chain management information system.

Design Improvement Based on the Analysis of Informational Materials for University Hospital Inpatient Hospitalization (대학병원 입원생활 안내문의 현황 분석과 디자인 개선 제안)

  • Kim, Ye Ji;Paik, Jin Kyung
    • Design Convergence Study
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    • v.14 no.5
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    • pp.1-14
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    • 2015
  • The purpose of this research is to analyze the current status of hospital life guides in Korean and overseas hospitals, draw problems, and propose a design improvement. in order to improve the visual convenience and efficiency of information delivery of hospital life guidelines. As a result of examining and analyzing the current status of the notice on hospital life in 16 hospitals at home and abroad, problems such as information selection without certain standard, increase of items due to unnecessary items, and forms that do not consider the convenience for notice use were discovered. In order to solve them, this study suggested a survey questionnaire for finding detailed improvements, and it divided the participants into two groups of 50 patients/nurses and 50 nurses in each. The study carried out a user awareness investigation and survey on the efficiency and understanding of information, number and importance of items, and color and form, and then made another sample notice to conduct a detailed survey on color and form. As a result, the study could identify that important items for each users were different. It is considered that a new design with improved visual convenience of users and efficiency of information delivery, by applying layout and graphic elements as well as selecting information that meets consumer demand, will be proposed based on this.

Preferences and Consumption Patterns of General Consumers of Meat Dishes (일반소비자들의 고기 요리에 대한 기호도 및 소비행태)

  • Kim, Eun-Mi;Seo, Sang-Hee;Lee, Min-A;Kwon, Ki-Hyun;Jun, Gi-Hong
    • Journal of the Korean Society of Food Culture
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    • v.25 no.3
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    • pp.251-261
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    • 2010
  • This paper examines the dining tendencies of Koreans toward meat dishes and their related factors, with 301 people residing in Korea as subjects. We questioned this population on their restaurant choices, eating habits, preferences and a dislike with respect to method of cooking. All age groups, with the exception of 50~60 year-olds, were found to consume meat dishes in specialized restaurants. The selection factor for restaurants varied, depending on the age group: affordable cost was the most important factor for whom under 20 year-old. Whereas 20-40 year-old people considered taste and ambience the most for choosing restaurant. The 50-60 year-old people found to seek for convenient restaurant. In terms of the most preferred parts of beef, 20-30 year-old people preferred tenderloin (42.3%) while 40-60 year-old people preferred sirloin (45.6% and 41.2% each). All the other age groups preferred ribs the most (It was also found that) men preferred the rib parts and women preferred tenderloin. With respect to pork, all age groups preferred pork belly, with the highest response rate in the under 20 age group. When consuming meat dishes, 91.0% of respondents pointed to roasting as the most frequent preparation method, the reason being good taste was deemed the highest number of responses. In a survey on preference for stewed meats, 74.8% of the sample pool was found to prefer stew dishes but 24.9% of respondents provided negative answers, the reason for dislike was found to be poor taste for women, and both a long preparation time and poor taste for men. In fact, regardless of marital status, a high number of responses were given for poor taste as the reason for disliking stew dishes. Based on the examined factors for inconveniences in preparing meat dishes, the most common inconvenience factor was the odor of meat left on clothes after the dining experience, followed by the smoke generated in roasting meat, and the safety risk involved with changing the grill. In terms of stir fry preparation, the negative thoughts were due to the splashing of food and spices while cooking, followed by the meat odor left on clothes after dining experience, and the sanitation level of the cooking containers. For deep frying the sanitation level of cooking containers was the biggest reason for dislike, followed by splashing of food when preparing. Lastly, it was indicated that the problem of steaming method was a difficulty of judging the portion, on the top of this, people found that the sanitation level of cooking container and a long preparation time were also the problem of this cooking method.

Effects of Self-Care Intervention Study on Chronic Obstructive Pulmonary Disease: Focusing on a Systematic Review of a Randomized Controlled Trials (만성폐쇄성폐질환의 자가간호 중재연구(RCT) 효과에 관한 체계적 문헌고찰)

  • Kyoung Mi Moon;Inhee Park;Hyun Joo Kim
    • Journal of Industrial Convergence
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    • v.21 no.8
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    • pp.97-110
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    • 2023
  • This study presents a systematic literature review aimed at integrating and analyzing the research findings regarding the components of various self-care intervention programs conducted for individuals with chronic obstructive pulmonary disease (COPD) both domestically and internationally. The paper selection criteria were established based on materials from PubMed, CINAHL, EMBASE, /MEDLINE, RISS, DBpia, KISS, and KMbase databases, covering the period from January 1, 2000, to September 30, 2022. The inclusion criteria included controlled pre-post experimental study designs. A total of 23 studies were included in this systematic review. The intervention-related factors examined included the sample size, type of intervention mediator, intervention frequency, and duration. Additionally, factors associated with intervention effects, such as measurement tools and variables, were analyzed. The findings of the analysis support the notion that self-care intervention programs for COPD can contribute to the prevention of symptom exacerbation and hospital readmissions among patients. Consequently, the development of a tailored self-care intervention program specifically designed for COPD patients in South Korea is warranted, considering aspects such as patient accessibility, convenience, and motivation for long-term sustainability.

Development and Verification of and Single Nucleotide Polymorphism Markers toDetermine Country of Origin of Korean and Chinese Scapharca subcrenata (한국산과 중국산 새꼬막(Scapharca subcrenata)의 원산지 판별을 위한 SNP 마커의 개발 및 검증)

  • Seong Seok Choi;Seung Hyun Yoo;Yong Bae Seo;Jong Oh Kim;Ik Jung Kwon;So Hee Bae;Gun Do Kim
    • Journal of Life Science
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    • v.33 no.12
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    • pp.1025-1035
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    • 2023
  • In this study, we analyzed SNPs that appear between Korean and Chinese Scapharca subcrenata using the nucleotide sequence data of S. subcrenata analyzed by genotyping by sequencing (GBS). To distinguish the country of origin for S. subcrenata in Korean and Chinese, we developed a primer set as single nucleotide polymorphism (SNP) markers for quantitative real-time PCR (qPCR) analysis and validated by sequencing SNPs. A total of 180 samples of S. subcrenata were analyzed by genotyping by sequencing, and 15 candidate SNPs were selected. SNP marker selection for country of origin were identified through real-time qPCR. Insertion 1 and SNP 21 markers showed the most distinct separation between the sequence types as well as the country of origin through qPCR, with the observed amplification patterns matching the expected outcomes.. Additionally, in a blind test conducted by mixing samples of S. subcrenata at random, Insertion 1 showed 74% accuracy, 52% sensitivity, and 96% specificity, and SNP 21 showed 86% accuracy, 79% sensitivity, and 93% specificity. Therefore, the two SNP markers developed are expected to be useful in verifying the authenticity of the country of origin of S. subcrenata when used independently or in combination.

Selection of Evaluation Metrics for Grading Autonomous Driving Car Judgment Abilities Based on Driving Simulator (드라이빙 시뮬레이터 기반 자율주행차 판단능력 등급화를 위한 평가지표 선정)

  • Oh, Min Jong;Jin, Eun Ju;Han, Mi Seon;Park, Je Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.44 no.1
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    • pp.63-73
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    • 2024
  • Autonomous vehicles at Levels 3 to 5, currently under global research and development, seek to replace the driver's perception, judgment, and control processes with various sensors integrated into the vehicle. This integration enables artificial intelligence to autonomously perform the majority of driving tasks. However, autonomous vehicles currently obtain temporary driving permits, allowing them to operate on roads if they meet minimum criteria for autonomous judgment abilities set by individual countries. When autonomous vehicles become more widespread in the future, it is anticipated that buyers may not have high confidence in the ability of these vehicles to avoid hazardous situations due to the limitations of temporary driving permits. In this study, we propose a method for grading the judgment abilities of autonomous vehicles based on a driving simulator experiment comparing and evaluating drivers' abilities to avoid hazardous situations. The goal is to derive evaluation criteria that allow for grading based on specific scenarios and to propose a framework for grading autonomous vehicles. Thirty adults (25 males and 5 females) participated in the driving simulator experiment. The analysis of the experimental results involved K-means cluster analysis and independent sample t-tests, confirming the possibility of classifying the judgment abilities of autonomous vehicles and the statistical significance of such classifications. Enhancing confidence in the risk-avoidance capabilities of autonomous vehicles in future hazardous situations could be a significant contribution of this research.

Prostatic Artery Embolization for Lower Urinary Tract Symptoms via Transradial Versus Transfemoral Artery Access: Single-Center Technical Outcomes

  • Ryun Gil;Dong Jae Shim;Doyoung Kim;Dong Hwan Lee;Jung Jun Kim;Jung Whee Lee
    • Korean Journal of Radiology
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    • v.23 no.5
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    • pp.548-554
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    • 2022
  • Objective: To evaluate the safety and feasibility of prostatic artery embolization (PAE) via transradial access (TRA) compared with transfemoral access (TFA). Materials and Methods: This retrospective study included 53 consecutive men with lower urinary tract symptoms (LUTS) who underwent PAE between September 2018 and September 2021. Thirty-one patients (mean age ± standard deviation: 70.6 ± 8.4 years) were treated with TFA, including 14 patients treated before adopting TRA. Since December 2019, TRA has also been attempted with the procedure's selection criteria of patent carpal circulation and a height ≤ 172 cm, with 22 patients treated via TRA (69.1 ± 9.6 years). Parameters of technical success (defined as successful bilateral embolization), clinical success (defined as LUTS improvement), procedural time, radiation dose, and adverse events were compared between the two groups using the Fisher's exact test, independent sample t test, Wilcoxon signed-rank test, or Mann-Whitney test. Results: All patients received at least one-side PAE. Technical success of PAE was achieved in most patients (TRA, 21/22; TFA, 30/31; p > 0.999). No technical problem-related conversion from TRA to TFA occurred. The clinical success rate was 85% (11/13) in patients with TRA, and 89% (16/18) in patients with TFA for follow-up > 2 weeks post-PAE (median, 3 months) (p > 0.999). The median procedure time was similar in both groups (TRA, 81 minutes vs. TFA, 94 minutes; p = 0.570). No significant dose differences were found between the TRA and TFA groups in the dose-area product (median Gycm2, 95 [range, 44-255] for TRA and 84 [34-255] for TFA; p = 0.678) or cumulative air kerma (median mGy, 609 [236-1584] for TRA and 634 [217-1594] for TFA; p = 0.551). No major adverse events occurred in either of the groups. Conclusion: PAE via TRA is a safe and feasible method comparable to conventional TFA. It can be safely implemented by selecting patients with patent carpal circulation and adequate height.

Selection of RAPD marker to discriminate the bolting-resistant varieties and commercial dried medicinal materials of Angelica species (당귀 내추대성 품종 및 건재약재 판별을 위한 RAPD marker 선발)

  • Bang, Kyong-Hwan;Yu, Hong-Seob;Koo, Dal-Hoe;Cho, Joon-Hyeong;Park, Hee-Woon;Seong, Nak-Sul;Park, Sang-Il;Kim, Hong-Sig
    • Korean Journal of Medicinal Crop Science
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    • v.10 no.1
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    • pp.46-50
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    • 2002
  • In DNA level, genetic study of Angelica species was firstly conducted to discriminate the bolting-resistant or low bolting variety, so called as Manchu, from other Korea collected lines and also this technuque was applied to identify the origin of commercial dried materials obtained from current oriental medicinal market. By RAPD analysis with 72 primers including sixty of 10-mers and twelve of 20-mers, respectively, three primers, which were related to the bolting resistant traits of Angelica gigas, were identified. Comparing the RAPD bands, URP04 primer showed the 1.7 kb specific band, which seemed to be related to delaying bolting traits, since it was observed only in Jinbu elite lines but not in others. On the other hand, since 1.2 kb band amplified by OPD11 was observed in other collected lines but not in Manchu var. and Jinbu line, this primer also could be considered as a selection marker for identifying bolting resistant or delaying bolting traits. In the same manner, since OPP09 did not show 1 kb major band but produced 0.8 kb and 1.2 kb bands in Manchu var., these three bands amplified by the primer could be considered one of the important key specifying Manchu var. related with the trait of Angelica gigas. OPC02 primer showed the same band patterns in all Korean collected lines, but not in other foreign introduced lines, such as A. sinensis from China, and A. acutiloba from Japan. Since these four RAPD primers, OPD11, OPP09, URP04, and OPC02 showed the specific polymorphisms in Angelica species, thus, these were useful to discriminate the three Angelica species, A. gigas, A. sinensis, and A. acutiloba.

Market Structure Analysis of Automobile Market in U.S.A (미국자동차시장의 구조분석)

  • Choi, In-Hye;Lee, Seo-Goo;Yi, Seong-Keun
    • Journal of Global Scholars of Marketing Science
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    • v.18 no.1
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    • pp.141-156
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    • 2008
  • Market structure analysis is a very useful tool to analyze the competition boundary of the brand or the company. But most of the studies in market structure analysis, the concern lies in nondurable goods such as candies, soft drink and etc. because of the their availability of the data. In the field of durable goods, the limitation of the data availability and the repurchase time period constrain the study. In the analysis of the automobile market, those of views might be more persuasive. The purpose of this study is to analyze the structure of automobile market based on some idea suggested by prior studies. Usually the buyers of the automobile tend to buy upper tier when they buy in the next time. That kind of behavior make it impossible to analyze the structure of automobile market under the level of automobile model. For that reason I tried to analyze the market structure in the brand or company level. In this study, consideration data was used for market structure analysis. The reasons why we used the consideration data are summarized as following. Firstly, as the repurchase time cycle is too long, brand switching data which is used for the market analysis of nondurable good is not avaliable. Secondly, as we mentioned, the buyers of the automobile tend to buy upper tier when they buy in the next time. We used survey data collected in the U.S.A. market in the year of 2005 through questionaire. The sample size was 8,291. The number of brand analyzed in this study was 9 among 37 which was being sold in U.S.A. market. Their market share was around 50%. The brands considered were BMW, Chevrolet, Chrysler, Dodge, Ford, Honda, Mercedes, and Toyota. �� ratio was derived from frequency of the consideration set. Actually the frequency is different from the brand switch concept. In this study to compute the �� ratio, the frequency of the consideration set was used like a frequency of brand switch for convenience. The study can be divided into 2 steps. The first step is to build hypothetical market structures. The second step is to choose the best structure based on the hypothetical market structures, Usually logit analysis is used for the choice best structure. In this study we built 3 hypothetical market structure. They are type-cost, cost-type, and unstructured. We classified the automobile into 5 types, sedan, SUV(Sport Utility Vehicle), Pickup, Mini Van, and Full-size Van. As for purchasing cost, we classified it 2 groups based on the median value. The median value was $28,800. To decide best structure among them, maximum likelihood test was used. Resulting from market structure analysis, we find that the automobile market of USA is hierarchically structured in the form of 'automobile type - purchasing cost'. That is, result showed that automobile buyers considered function or usage first and purchasing cost next. This study has some limitations in the analysis level and variable selection. First, in this study only type of the automobile and purchasing cost were as attributes considered for purchase. Considering other attributes is very needful. Because of the attributes considered, only 3 hypothetical structure could be analyzed. Second, due to the data, brand level analysis was tried. But model level analysis would be better because automobile buyers consider model not brand. To conduct model level study more cases should be obtained. That is for acquiring the better practical meaning, brand level analysis should be conducted when we consider the actual competition which occurred in the real market. Third, the variable selection for building nested logit model was very limited to some avaliable data. In spite of those limitations, the importance of this study lies in the trial of market structure analysis of durable good.

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