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        검색결과 9,893

        1981.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        COVID-19 has been spreading all around the world, and threatening global health. In this situation, identifying and isolating infected individuals rapidly has been one of the most important measures to contain the epidemic. However, the standard diagnosis procedure with RT-PCR (Reverse Transcriptase Polymerase Chain Reaction) is costly and time-consuming. For this reason, pooled testing for COVID-19 has been proposed from the early stage of the COVID-19 pandemic to reduce the cost and time of identifying the COVID-19 infection. For pooled testing, how many samples are tested in group is the most significant factor to the performance of the test system. When the arrivals of test requirements and the test time are stochastic, batch-service queueing models have been utilized for the analysis of pooled-testing systems. However, most of them do not consider the false-negative test results of pooled testing in their performance analysis. For the COVID-19 RT-PCR test, there is a small but certain possibility of false-negative test results, and the group-test size affects not only the time and cost of pooled testing, but also the false-negative rate of pooled testing, which is a significant concern to public health authorities. In this study, we analyze the performance of COVID-19 pooled-testing systems with false-negative test results. To do this, we first formulate the COVID-19 pooled-testing systems with false negatives as a batch-service queuing model, and then obtain the performance measures such as the expected number of test requirements in the system, the expected number of RP-PCR tests for a test sample, the false-negative group-test rate, and the total cost per unit time, using the queueing analysis. We also present a numerical example to demonstrate the applicability of our analysis, and draw a couple of implications for COVID-19 pooled testing.
        4,800원
        1982.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 종교적 언어가 신을 나타낼 수 있음을 보여주고자 한다. 종교적 체험과 종교적 언어의 관계성에서, 중요한 주제들 중의 하나는 신적 체험을 전달 하는데 사용되는 언어가 인간의 조건과 존재론적으로 명확히 구별되는 신을 나타낼 수 있는가의 문제를 다루는 것이다. 신과 세계의 사이에는 차이 혹은 간격이 있다. 왜냐하면 초월적 존재로서 신은 인간이 이해할 수 없는 존재의 측면을 가지고 있기 때문이다. 신에 대한 이해불가능성은 아마도 인간 언어가 지니고 있는 한계점들을 암시하고 있을 것이다. 즉 인간 언어는 인간이 이해할 수 없는 것을 표현할 수 없는 한계점이 있다. 그러나 세계가 신을 나타낼 수 있는 중요 한 영역들 중의 하나는 바로 경험의 세계이다. 한 개인은 바로 경험의 역동성을 통해서 신을 만나게 된다. 신에 대한 인간의 체험을 전달하는 것은 바로 인간의 언어이다. 그리고 이러한 인간의 언어는 현존하는 것뿐만 아니라 부재하는 것도 드러낼 수 있다. 따라서 본 논문은 어떻게 종교적 언어가 신을 나타낼 수 있는 가에 대해서 보여주고자 한다. 전통과 공동체의 중요성, 종교적 언어의 본질, 그리고 종교적 언어의 변화적 힘 등이 논의될 것이다.
        4,600원
        1983.
        2021.12 구독 인증기관 무료, 개인회원 유료
        The 17th APEC Future Education Forum (AFEF) and the 19th International ALCoB Conference were held from 28 September (Tuesday) to 1 October (Friday) in a virtual manner. The annual forum and conference serve as an invaluable opportunity to discuss future directions of education and human resources development in the Asia-Pacific region. Since 2005, the forum and conference have served their role as the largest and longest thematic meeting in the APEC Human Resources Development Working Group (HRDWG). The 2021 forum and conference have gathered 780 participants from 20 APEC member economies, guest economies and international institutions. Under the theme “Strengthening lifelong competencies and skills development for individuals’ career, education, training, and life cycles”, the forum and conference reflected the current educational agenda from 21 APEC member economies and other international organizations such as G20, UNESCO. As a way forward, the forum and conference speakers recommend APEC to 1) consider individual and industrial needs for curriculum development, 2) expand lifelong learning policies and practices at both domestic and international level and 3) develop a public-private partnership to prepare its future talents with adequate competencies. This review explains the 17th AFEF and the 19th International ALCoB Conference background, summary and outcomes. The review also briefs on collective actions member economies can take as future steps to continue the forum and conference discussions.
        4,000원
        1984.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This article suggests the machine learning model, i.e., classifier, for predicting the production quality of free-machining 303-series stainless steel(STS303) small rolling wire rods according to the operating condition of the manufacturing process. For the development of the classifier, manufacturing data for 37 operating variables were collected from the manufacturing execution system(MES) of Company S, and the 12 types of derived variables were generated based on literature review and interviews with field experts. This research was performed with data preprocessing, exploratory data analysis, feature selection, machine learning modeling, and the evaluation of alternative models. In the preprocessing stage, missing values and outliers are removed, and oversampling using SMOTE(Synthetic oversampling technique) to resolve data imbalance. Features are selected by variable importance of LASSO(Least absolute shrinkage and selection operator) regression, extreme gradient boosting(XGBoost), and random forest models. Finally, logistic regression, support vector machine(SVM), random forest, and XGBoost are developed as a classifier to predict the adequate or defective products with new operating conditions. The optimal hyper-parameters for each model are investigated by the grid search and random search methods based on k-fold cross-validation. As a result of the experiment, XGBoost showed relatively high predictive performance compared to other models with an accuracy of 0.9929, specificity of 0.9372, F1-score of 0.9963, and logarithmic loss of 0.0209. The classifier developed in this study is expected to improve productivity by enabling effective management of the manufacturing process for the STS303 small rolling wire rods.
        4,200원
        1985.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, the importance of preventive maintenance has been emerging since failures in a complex system are automatically detected due to the development of artificial intelligence techniques and sensor technology. Therefore, prognostic and health management (PHM) is being actively studied, and prediction of the remaining useful life (RUL) of the system is being one of the most important tasks. A lot of researches has been conducted to predict the RUL. Deep learning models have been developed to improve prediction performance, but studies on identifying the importance of features are not carried out. It is very meaningful to extract and interpret features that affect failures while improving the predictive accuracy of RUL is important. In this paper, a total of six popular deep learning models were employed to predict the RUL, and identified important variables for each model through SHAP (Shapley Additive explanations) that one of the explainable artificial intelligence (XAI). Moreover, the fluctuations and trends of prediction performance according to the number of variables were identified. This paper can suggest the possibility of explainability of various deep learning models, and the application of XAI can be demonstrated. Also, through this proposed method, it is expected that the possibility of utilizing SHAP as a feature selection method.
        4,200원
        1986.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study investigated the individual coaching effect on TOEIC learning among college students. The participants were the 145 college students in Incheon who had taken TOEIC reading comprehension classes for two semesters. Two series of simple TOEIC tests were executed to measure the students’ English proficiency on the first day of each semester. Individual coaching was conducted through counseling and learning guidance for 25 students with the lower scores (3~7 points out of 25 based on the first simple TOEIC test). Among them, eight students participated in the in-depth interview at the beginning of each semester. When comparing the simple TOEIC test results of the two groups, the difference between the averages of the two groups was clear only with regard to the first semester. The t-test showed no proven statistical differences in the second semester outcomes. The results of paired-sample t-test on the change in the simple TOEIC scores before and after individual coaching in the individual and class coaching mixed group was also statistically verified. Individual coaching in this study was to find an appropriate learning process for the students with low language fluency, and it took place for a relatively long time. The interaction between the students and the professor in individual coaching created a special rapport between them.
        6,600원
        1987.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        고치벌과에 속하는 Microgastrinae 아과의 Diolcogaster perniciosa (넓적다리도랑꼬마고치벌)을 한국에서 처음으로 보고한다. 본 종의 재기 재, 진단, 분포정보, 그리고 삽화를 제공한다.
        3,000원
        1988.
        2021.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Laser cladding a surface treatment process that grants superior characteristics such as toughness, hardness, and corrosion resistance to the surface, and rebuilds cracked molds; as such, it can be a strong tool to prolong service life of mold steel. Furthermore, compared with the other similar coating processes – thermal spray, etc., laser cladding provides superior bonding strength and precision coating on a local area. In this study, surface characteristics are studied after laser cladding of low carbon steel using 18%Cr-2.5%Ni-Fe powder (Rockit404), known for its high hardness and excellent corrosion resistance. A diode laser with wavelength of 900-1070 nm is adopted as laser source under argon atmosphere; electrical power for the laser cladding process is 5, 6, and 10 kW. Fundamental surface characteristics such as crossectional microstructure and hardness profile are observed and measured, and special evaluation, such as a soldering test with molten ALDC12 alloy, is conducted to investigate the corrosion resistance characteristics. As a result of the die-soldering test by immersion of low carbon alloy steel in ALDC12 molten metal, the clad layer's soldering thickness decreases.
        4,000원
        1989.
        2021.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Physical activity and quality of life (QOL) influence the health status of older adults. Recently, the use of wearable devices to monitor physical activity has increased. Objects: This study examined the relationship between the amount of physical activity, measured using a wearable device, and QOL among older adults. Methods: In total, 71 older adults (aged ≥ 65 years) were enrolled. The amount of physical activity was measured using a wearable device with a wrist strap, and daily physical activity was classified according to intensity (sedentary, light, moderate, or very active). Self-reported QOL was evaluated using the Short Form 36 (SF-36) questionnaire. Pearson and Spearman correlation analyses were conducted to analyze parametric and non-parametric variables, respectively. The relationship between amount of daily physical activity and SF-36 scores was assessed. Results: The correlation analyses revealed positive correlations between the amount of moderate- intensity and very active physical activity (minutes/day) and SF-36 scores (p < 0.05). Conclusion: Physical activity of at least moderate intensity is associated with better QOL in older adults. Further studies are required to verify the effects of increased physical activity on QOL in older adults.
        4,000원
        1990.
        2021.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: The International Classification of Functioning, Disability, and Health-Child and Youth version (ICF-CY) is designed to record the characteristics of developing children and examine the influence of a child’s environment on their health. Objects: This study was designed to determine the relationship between the clinically extracted ICF-CY items and The Pediatric Evaluation of Disability Inventory (PEDI) and Gross Motor Function Measure (GMFM) items. Methods: Thirty patients (17 males and 13 females) who were hospitalized in a pediatric and youth patient unit of a rehabilitation hospital were included in the study. Four health professionals (two physical therapists and two occupational therapists) working independently linked the PEDI and GMFM-66 items to the activity and participation domains of the ICF-CY. Results: There were strong negative correlations between the ICF-CY subdomains and the PEDI subdomains (r = 0.76–0.95; p < 0.05). There were positive strong correlations between the ICF-CY subdomains and the GMFM-66 (r = 0.76–0.95; p < 0.05). Conclusion: The extracted ICF codes were a valid tool for evaluating the mobility and selfcare conditions of cerebral palsy in the pediatric rehabilitation area.
        4,000원
        1991.
        2021.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since the Japanese government recently unveiled a plan to release radioactive water into the ocean, the neighbouring countries have expressed concerns. In particular, certain environmental groups claimed that the execution of this operation would have a significant impact on the marine environment in the region. In light of significant potential risks, this article argues that such an operation is likely to trigger an international dispute at an international court or tribunal for several reasons. Accordingly, this article would like to explore the highly likely international litigation. First, the background of this potential international litigation, including the reasons why the operation may end up at an international court or tribunal are addressed. Subsequently, certain legal and factual issues that are expected to be contested between the parties at the court or tribunal are discussed. Finally, this article discusses some of the expected outcomes of this likely international litigation, including reparation.
        6,400원