• 응용통계연구
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• 제17권3호
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• pp.459-473
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• 2004

본 논문에서는 Breiman 등(1984)의 전체탐색법이 갖고 있는 변수선택 편향을 극복할 수 있는 알고리즘을 제안하였다. 제안한 알고리즘은 노드의 분리 변수를 선택하는 단계와 그 선택된 변수에 대해서만 이진분리를 위한 분리점을 찾는 단계로 나뉘어져 있다. 예측변수가 연속형 일 때는 스피어만의 순위상관계수에 의한 검정을 수행하고, 범주형일 때는 크루스칼-왈리스의 통계량에 의한 검정을 수행하여 통계적으로 가장 유의한 변수를 분리변수로 선택하였고 Breiman 등(1984)의 전체탐색법을 그 변수에만 적용하여 노드의 분리기준을 정하였다 모의실험 연구를 통해 Breiman등(19히)의 CART와 제안한 알고리즘을 변수선택 편의, 변수선택력파 평균제곱오차 측면에서 서로 비교하였다. 아울러 두 알고리즘을 실제 자료에 적용하여 효율을 서로 비교하였다.

• 한국산업정보학회논문지
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• 제21권3호
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• pp.13-19
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• 2016

최근에 실시간 처리를 위해 메모리 기반의 빅데이터 처리 프레임 워크인 스파크가 널리 사용되고 있다. 스파크는 프로그램이 필요로 하는 중간 데이터를 모두 메모리에 올려놓아, I/O 수행을 최소화함으로써 빠른 응답을 가져올 수 있다. 그러나 응용프로그램의 메모리 사용량이 클러스터의 실제 메모리의 량보다 많을 경우, 최적의 성능을 기대하기 어렵다. 본 논문에서는 메모리 사용량이 많은 페이지랭크 응용 프로그램에서 병목이 되는 현상을 실험을 통해 그 요인에 대해 분석하고, 스파크와 함께 타키온을 구성해서 메모리의 효율적 사용을 통해 병목의 요인을 해결하여 18%의 성능향상을 하였다.

• 대한안전경영과학회지
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• 제10권4호
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• pp.1-9
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• 2008

It is very important to evaluate the priority of prevention factors and strategies in order to minimize industrial accident. It provides decisive information for accident prevention and safety management. Therefore, this paper proposes evaluation method of the priority through statistic testing with prevention factors and strategies by the cause analysis of cause and effect models. Especially, this paper uses priority matrix criterion to justify application of rank and objectivity. This paper is based on the results of a questionnaire of workers and managers who are engaged by real manufacturing and construction industries with less than 300 workers in the central region of Korea, where most of the fatal accidents have happened. Finally, the result provides one way to implement safety management for industrial accident prevention.

• 한국항만학회지
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• 제7권1호
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• pp.13-24
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• 1993

The rapid progress of the intermodal freight transportation in recent years has induced fierce competition among the adjacent hub ports for container transport. This brings increased attention to the evaluation of the port competitive ability. But it is not easy to evaluate the port competitive ability because this belongs to ill-defined system which is composed of ambiguous interacting attributes. Paying attention to this point, this paper deals the competitive ability of container port in Far-East Asia by fuzzy integral evaluation which is adequate to interacting ambiguous attribute problem. For this, the proposed fuzzy evaluation algorithm is applied to the real problem, based on the factors such as cargo volumes, costs, services, infrastructure and geographical sites These are extracted from the precedent study of port competitive ability, etc. The results show that the port evaluation factors come in following order ; services, costs, infrastructure, geographical sites and cargo volumes. There are some interactions(interaction coefficient, ${\lambda}=-0.664$ between evaluation attributes. The port competitive ability comes in following order : Singapore, Hongkong, Kobe, Kaoshiung and Busan. According to the sensitivity analysis, the rank between Busan and Kaoshiung changes when ${\lambda}=0.7$. From the analysis of the results, we confirmed that the proposed fuzzy evaluation algorithm is very effective in the complex-fuzzy problem which is composed of hierarchical structure with interacting attributes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권1호
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• pp.35-57
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• 2014

Multi-criteria decision making (MCDM) algorithms play an important role in ensuring quality of service in an integrated HetNets (Heterogeneous Networks). The primary objective of this paper is to develop a multi-criteria vertical handoff decision algorithm (VHDA) for best access network selection in an integrated Wireless Local Area Network (WLAN)/Universal Mobile Telecommunications System (UMTS)/Worldwide Interoperability for Microwave Access (WiMAX) system. The proposed design consists of two parts, the first part is the evaluation of an Analytic Hierarchy Process (AHP) to decide the relative weights of handoff decision criteria and the second part computes the final score of the weights to rank network alternatives using Simple Additive Weighting (SAW). SAW ranks the network alternatives in a faster and simpler manner than AHP. The AHP-SAW mathematical model has been designed, evaluated and simulated for streaming video type of traffic. For other traffic type, such as conversational, background and interactive, only simulation results have been discussed and presented in brief. Simulation results reveal that the hierarchical modelling and computing provides optimum solution for access network selection in an integrated environment as obtained results prove to be an acceptable solution to what could be expected in real life scenarios.

• Safety and Health at Work
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• 제7권2호
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• pp.120-123
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• 2016

Background: To assess in a laboratory setting the ability to stay awake in a sample of workers of an Italian hospital and to investigate the association between that ability and the risk of occupational injury. Methods: Nine workers at the University Hospital of Udine who reported an occupational injury in the study period (cases), and seven noninjured workers (controls) underwent a polysomnography and four 40-minute maintenance of wakefulness tests (MWT). Differences in sleep characteristics and in wakefulness maintenance were assessed using Wilcoxon's rank sums tests and Fisher's exact tests. Results: Controls had greater sleep latency, lower total sleep time, fewer leg movements, and a higher percentage ratio of cycling alternating pattern, were more likely not to fall asleep during the MWT and were less likely to have two or more sleep onsets. Although not all the differences reached statistical significance, cases had lower sleep onset times in Trials 1-3. Conclusion: In the literature, the evidence of an association between MWT results and real life risk of accidents is weak. Our results suggest a relationship between the MWT results and the risk of injury among hospital workers.

• International journal of advanced smart convergence
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• 제10권4호
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• pp.233-240
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• 2021

The purpose of this study was to provide a 360-degree video on intensive care unit admission guidance to family members admitted to the intensive care unit, and then to identify anxiety, safety perception, and satisfaction. This study was a single-group pre-post design, and the data collection period was from October 1, 2020 to August 30, 2021. The subjects of this study were 19 people who applied 360 degree hospitalization guide video. For data analysis, SPSS WIN 24.0 program was used, and real number, percentage, mean, standard deviation, minimum value, maximum value, and Wilcoxon signed rank test were used. The subjects' anxiety before intervention was an average score of 6.21±2.30 and the anxiety after intervention was an average score of 3.95±2.46, which was statistically significant (z=4.13, p<.001). The safety consciousness of the subjects before the intervention was an average of 4.08±0.39 and the safety consciousness after the intervention was an average of 4.54±0.48, which was statistically significant (z=5.00, p=.001). The highest level of satisfaction with the 360-degree hospitalization guidance image of the subjects was 4.58±0.51 and the lowest was 4.16±0.96. In this study, when 360-degree hospitalization guide video was applied, there was a difference in anxiety and safety perception, and satisfaction was high. Based on the research results, various programs for guardian education can be developed and utilized in the future.

• 대한간호학회지
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• 제51권4호
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• pp.454-464
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• 2021

Purpose: This study aimed to identify the level of complete knowledge about hand hygiene indications among nurses working at integrated nursing care service wards. Methods: A total of 127 nurses in eight integrated nursing care service wards completed structured sheets while observing a video based on six scenarios developed by the research team. Complete knowledge level was calculated as the percentage (%) of participants who responded correctly to all questions among participants. Complete knowledge levels according to the scenarios were calculated and compared according to general characteristics using the chi-squared test or Wilcoxon rank-sum test. Results: The complete knowledge level for each scenario ranged from 7.9% (scenario 6) to 42.5% (scenarios 4 and 5), and no one had complete knowledge of all scenarios. Only 3.1% of participants demonstrated complete knowledge in more than four scenarios, and 26.0% had complete knowledge of four or more hand hygiene moments. Complete knowledge level per scenario did not differ depending on work experience at hospitals and study wards, or prior hand hygiene training in the last year. Conclusion: As the complete knowledge level regarding hand hygiene moment is very low, it is suggested that regular hand hygiene training should be provided to nurses using video media that reflect real nursing tasks. Thus, they can acquire complete knowledge of when hand hygiene is needed or not during complex nursing work situations.

• Journal of Animal Science and Technology
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• 제60권5호
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• pp.14.1-14.12
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• 2018

Background: Sheep production is a major component of the livestock sector in Ethiopia. The country owing to the large population of 30.70 million estimated numbers of sheep in the country and out of which about 72.14% are females, and 27.86% are males with diverse genetic resources. The real value of indigenous breeds was often under-estimated mostly due to their poor appearance and relatively low productivity. Developing countries in most cases opt for exotic breeds to increase animal productivity through crossbreeding or breed substitution without properly investigating the production potential of the indigenous breeds. The main objective of the research was to identify sheep flock composition and structure, farmers' traits of interest and breeding objective of Wollo highland sheep, and their $F_1$ crossbreed progenies. Results: Smallholder farmers' flock synthesized from breeding ewes, breeding rams, pre-weaned ewe lambs, pre-weaned ram lambs, unproductive ewes, castrated and fattened rams, with the percentage coverage of 29.2, 13.3, 15.5, 16.5, 12.4, and 12.5%, respectively. The maximum number of flock size was 289.0 sheep per flock and higher in the third stratum. The off-take rate percentage of the three strata presented as 21.9% in 1st stratum, 12% in the 2nd stratum, and 16.4% in the 3rd stratum and higher off-take rate recorded in the first stratum. Sheep producer's traits of interest ranked by growth rate (first), body size (second) and marketing value was third rank. Communal breeding (random mating), village based controlled breeding, mixed type and private ram controlled breeding practice were comprised of 39.7, 61.7, 52 and 71.3%, respectively. The percentages of ewes per flock composition were presented as 36.5, 27.1 and 25.5%, respectively in the 3rd stratum, 2nd stratum and 3rd stratum in the order of their importance's. Conclusion: Genetic improvement practices at smallholder sheep producers situation was showing promising outcome with indigenous Washera $F_1$ crossbred lambs and which designated for weaning rate, body size, marketing age, age at first lambing, good temperament and large litter size in the order of their rank. The contemporary breeding practice tendency indicated that, reduced flock size to improve flock productivity via crossbreeding practices.

• Journal of Korean Medical Science
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• 제33권51호
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• pp.325.1-325.10
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• 2018

Background: To evaluate survival outcomes and prognostic factors for overall survival (OS) in patients with metastatic renal cell carcinoma (mRCC) who received sunitinib (SU) and pazopanib (PZ) as first-line therapy in real-world Korean clinical practice. Methods: Data of 554 patients with mRCC who received SU or PZ at eight institutions between 2012 and 2016 were retrospectively reviewed. Based on the targeted therapy, the patients were divided into SU (n = 293) or PZ (n = 261) groups, and the clinicopathological variables and survival rates of the two groups were compared. A multivariable Cox proportional hazard model was used to determine the prognostic factors for OS. Results: The median follow-up was 16.4 months (interquartile range, 8.3-31.3). Patients in the PZ group were older, and no significant difference was observed in the performance status (PS) between the two groups. In the SU group, the dose reduction rate was higher and the incidence of grade 3 toxicity was more frequent. The objective response rates were comparable between the two groups (SU, 32.1% vs. PZ, 36.4%). OS did not differ significantly between the two groups (SU, 36.5 months vs. PZ, 40.2 months; log-rank, P = 0.955). Body mass index, Eastern Cooperative Oncology Group PS > 2, synchronous metastasis, poor Heng risk criteria, and liver and bone metastases were associated with a shorter OS. Conclusion: Our real-world data of Korean patients with mRCC suggested that SU and PZ had similar efficacies as first-line therapy for mRCC. However, PZ was better tolerated than SU in Korean patients.