• Journal of Electrical Engineering and Technology
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• 제12권5호
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• pp.1955-1962
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• 2017

Induction motors are a workhorse for the industry. The condition monitoring and fault analysis are the main concern for the engineers. The bearing is one of the vital segment of the induction machine and the condition of the whole machine is decided based on the condition of the bearing. In the present paper, the vibration signal of the bearing has been used for the analysis. The first line of action is to perform a statistical analysis of the vibration signal which gives trends in signal. To get the location of a fault in the bearing the second action is to develop an index based on Wavelet Packet Transform node energy named as Bearing Damage Index (BDI). Further, Teager-Kaiser Energy Operator (TKEO) has been calculated from higher index value to get the envelope and finally Power Spectral Density (PSD) has been applied to identify the fault frequencies. A performance index has also been developed to compare the usefulness of the proposed method with other existing methods. The result shows that the strong amplitude of fault characteristics and its side bands help to decide the type of fault present in the recorded signal obtained from the bearing.

• 한국응급구조학회지
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• 제24권3호
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• pp.41-53
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• 2020

Purpose: This study tests the validity of a standard evaluation tool of ambulance ride practices with new evaluation items and supports its application by 119 preceptors. Methods: We tested the validity of standard evaluation items collected from 19 on-site professionals assessing ambulance ride practices. New evaluation items, 'understanding of emergency rescue equipment' and 'ability to communicate', were added as additional criteria. The modified Delphi technique was used to test the three evaluation areas and ten evaluation items. We used the analytic hierarchy process to analyze the weighting value of the reconstructed evaluation tool model. Results: All three evaluation areas and 10 evaluation items within the standard evaluation tools used for ambulance ride practices corresponded with the consistency index, degree of convergence, and agreement in the modified Delphi panel. Conclusion: These results provide evidence of the consistency and usefulness behind preceptors' use of this standard evaluation tool in ambulance ride practice.

• 한국문헌정보학회지
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• 제49권2호
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• pp.27-49
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• 2015

The purpose of this study is to suggest an appropriate index for evaluating preferences of Web contents by examining the h-index and its variants. It focuses on how successfully each index represents relative user preference towards topical subjects. Based on data obtained from a popular IT blog (engadget.com), subject values of the h-index and its variants were calculated using 53 subject categories, article counts and the 'Likes' counts aggregated in each category. These values were compared through critical analysis of the indices and Spearman rank correlation analysis. A PFNet (Pathfinder Network) of subjects weighted by $h_T$ values was drawn and cluster analysis was conducted. Based on the four criteria suggested for the evaluation of Web contents, we concluded that the $h_T$-index is a relatively appropriate tool for the Web contents preference evaluation. The $h_T$-index was applied to visually represent the relative weight (topic preference by user 'Likes' count) for each subject category of the real online contents after suggesting the relative appropriateness of the $h_T$-index. Applying scientometric indicators to Web information could provide new insights into, and potential methods for, Web contents evaluation. In addition, information on the focus of users' attention would help online informants to plan more effective content strategies. The study tries to expand the application area of the h-type indices to non-academic online environments. The research procedure enables examination of the appropriateness of the index and highlights considerations for applying the indicators to Web contents.

• Journal of Preventive Medicine and Public Health
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• 제42권1호
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• pp.49-58
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• 2009

Objectives : The purpose of the current study was to evaluate the usefulness of the following four comorbidity indices in gastric cancer patients who underwent surgery: Charlson Comorbidity Index(CCI), Cumulative Illness rating scale(CIRS), Index of Co-existent Disease(ICED), and Kaplan-Feinstein Scale(KFS). Methods : The study subjects were 614 adults who underwent surgery for gastric cancer at K hospital between 2005 and 2007. We examined the test-retest and inter-rater reliability of 4 comorbidity indices for 50 patients. Reliability was evaluated with Spearman rho coefficients for CCI and CIRS, while Kappa values were used for the ICED and KFS indices. Logistic regression was used to determine how these comorbidity indices affected unplanned readmission and death. Multiple regression was used for determining if the comorbidity indices affected length of stay and hospital costs. Results : The test-retest reliability of CCI and CIRS was substantial(Spearman rho=0.746 and 0.775, respectively), while for ICED and KFS was moderate(Kappa=0.476 and 0.504, respectively). The inter-rater reliability of the CCI, CIRS, and ICED was moderate(Spearman rho=0.580 and 0.668, and Kappa=0.433, respectively), but for KFS was fair(Kappa=0.383). According to the results from logistic regression, unplanned readmissions and deaths were not significantly different between the comorbidity index scores. But, according to the results from multiple linear regression, the CIRS group showed a significantly increased length of hospital stay(p<0.01). Additionally, CCI showed a significant association with increased hospital costs (p<0.01). Conclusions : This study suggests that the CCI index may be useful in the estimation of comorbidities associated with hospital costs, while the CIRS index may be useful where estimatation of comorbiditie associated with the length of hospital stay are concerned.

• Journal of the Korean Data and Information Science Society
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• 제24권2호
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• pp.235-244
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• 2013

본 연구에서는 코스피200 선물시장에서 거래량 지표를 이용한 매매 전략을 제안한다. 거래량과 주가의 인과성에 대한 많은 연구가 진행되어 왔으나 뚜렷한 결과를 도출하지 못하였지만, 본 연구에서는 거래량을 사용하는 투자전략의 경제적 유용성을 실증 분석하여 거래량이 주가의 선행 지표라는 것을 지지하였다. 본 연구는 크게 두 가지 목적을 가지고 있다. 첫 번째 목적은 CVI (correlated volume index)라는 거래량을 사용한 지표를 생성하는 것이다. 두 번째 목적은 이를 이용하여 코스피200 선물 지수의 적절한 매수시점과 매도시점을 정하는 것이다. 이 논문의 실험결과는 제안된 모델의 유용성을 증명할 수 있을 것이며, 또한 이를 통해 시장참여자들의 투자 결정에 있어 도움을 줄 수 있을 것이다.

• Tuberculosis and Respiratory Diseases
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• 제71권4호
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• pp.271-277
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• 2011

Background: A chronic obstructive pulmonary disease (COPD) assessment test (CAT) has recently been developed as a short and simple method for assessing the quality of life in COPD patients. The object of this study was to assess the usefulness of the Korean version of the CAT for assessing COPD patients in an outpatient clinic. Methods: The study included 60 COPD patients in a stable state from an outpatient clinic. The authors investigated the frequency of acute exacerbation during aprevious year through reviewing medical records. We evaluated the spirometry test, a 6-min walk distance test, and obtained the MMRC dyspnea scale, the Korean version of the CAT, and the BODE index at the time of visit. To assess the usefulness of the CAT, correlations between the CAT and other methods were evaluated. Results: The mean age of patients was $68.3{\pm}8.6$ years and 95% of patients were male. There was a significant correlation between the CAT score and $FEV_1%$ (r=-0.323, p=0.012), the frequency of acute exacerbation (r=0.292, p=0.024), the MMRC dyspnea scale (r=0.554, p<0.001), the BODE index (r=0.380, p=0.003), and 6 MWD (r=-0.372, p=0.004). The mean CAT score increased according to the GOLD stage (stage 1, $10.7{\pm}4.5$; stage 2, $13.1{\pm}7.9$; stage 3, $16.3{\pm}6.2$; stage 4, $16.5{\pm}14.8$; p=0.746). Conclusion: The CAT was shown to be useful for the assessment of COPD severity. Therefore, the CAT is an easily applied and simple method for assessing COPD severity in an outpatient clinic.

• 한국자동차공학회논문집
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• 제12권5호
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• pp.136-145
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• 2004

In companion paper, the composition and structure of the traffic environment is derived. Rules to regulate agent behaviors and the frameworks to communicate between the agents are proposed. In this paper, the model of a driver agent which controls a vehicle agent is constructed. The driver agent is capable of having different driving styles. That is, each driver agent has individual behavior settings of the yielding index and the passing index. The yielding index can be defined as how often the agent yields in case of lane changes, and the passing index can be defined as how often the agent passes ahead. According to these indices, the agents overtake or make their lanes for other vehicles. Similarly, the vehicle agents can have various vehicle dynamic models. According to their dynamic characteristics, the vehicle agent shows its own behavior. The vehicle model of the vehicle agent contains the nonlinear subcomponents of engine, torque converter, automatic transmission, and wheels. The simulation has proceeded for an interrupted flow model. The result has shown that it is possible to express the characteristics of each vehicle and its driver in a traffic flow, and that the change of the traffic state is closely related with the distance and the signal delay between intersections. The system developed in this paper shows the effectiveness and the practical usefulness of the traffic simulation.

• 대한수의학회지
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• 제44권4호
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• pp.649-653
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• 2004

To estimate the source of variance components for some hematological parameters and assess the utility of the conventional population-based reference interval, this study computed index of individuality for blood samples, which were from 13 dogs drawn once weekly for 4 consecutive weeks. Results were subjected to nested analysis of variance. For all parameters measured between-dog variations were greater than within-dog variation. Except for the parameters RBC and MCHC the index of individuality was <1.4. The low reliability coefficient and high index of individuality of ${\leq}0.8$ were found for the majority of hematological parameters. In practical term, the present study indicated that use of hemogram profiles alone in the evaluating clinical state of a single patient should be avoided because of their physiological or natural random variations, and that comparing a single measurement on the blood analytes from an individual dog to the conventional population-based reference range may be too insensitive to detect any significant changes in the blood components of that particular dog. A single measurement may not characterize an individual's average concentration of the parameters even shortterm period.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1414-1418
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• 2009

International construction projects typically manifest difficult, complex, and varied types of risk exposures; because of this, there is a need for accurate evaluation of risk-integrated performances during the timeframe of project execution. Given the financial crisis currently affecting the world economy recession, risk management has become a more crucial part for the success of international project management. However, the majority of risk management approaches, particularly for overseas projects, are focused primarily on simple forms of checklists, formalization of risk variables affecting project performance for a specific phase, or more complicated computational methods that restricting practical utilization in real-world projects; moreover, these methods lack the conceptual basis to broadly visualize the level of risk over all phases of a project. This study suggests an efficient, yet simple risk-integrated total index to successfully assess the risk levels of overseas construction projects. To this end, this paper first investigates the life cycles and key processes of decision-making for a given project and then derives formulas to represent the total risk index (TRI) along the key decision-making processes. In addition, the study examines the relationships between TRI and performance levels based on the analysis of 126 real-world project samples. Validations using the proposed TRI showed a high correlation to project performance, signifying the usefulness of the proposed approach for construction firms when investigating the level of risks and key areas for management focus.

• 대한지역사회영양학회지
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• 제27권2호
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• pp.146-157
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• 2022

Objectives: This study aimed to develop and assess the content validity and internal consistency of a questionnaire on the feasibility of mobile dietary self-monitoring applications. Methods: We developed a feasibility questionnaire to assess the overall usage, convenience, usefulness, and satisfaction of mobile dietary applications. The initial draft of the questionnaire contained 17 items with yes/no, multiple-choice, and open-ended questions and 52 items on 5-point Likert scales. To validate the content, ten experts evaluated the relevance of the items for each subscale using a 5-point scale. We calculated the item-level content validity index (I-CVI) and scale-level content validity index (S-CVI). A total of 102 adults answered the questionnaires which reflected the experts' reviews. We conducted an exploratory factor analysis to determine the underlying structure of responses and categorized convenience, usefulness, and satisfaction. We also calculated Cronbach's alpha coefficient to examine the internal consistency of items in each subscale. Results: The S-CVI score of the items was 0.86, and we removed items with an I-CVI score of < 0.80. We combined, revised, or separated some remaining items and added one item as per the experts' comments. As a result, we included 16 items about overall usage and 42 sub-questions. Based on the responses of the 102 adults, we performed exploratory factor analysis using the principal axis method. We retained items with a factor loading of > 0.40, resulting in a final set of 35 questions (convenience: 15, usefulness: 12, satisfaction: 8 items). The Cronbach's alpha values of the three scales were 0.93, 0.91, and 0.91 for 1) usefulness, 2) convenience, and 3) satisfaction, respectively. Conclusions: We developed a feasibility questionnaire for mobile dietary self-monitoring applications and examined its content validity and internal consistency. Our questionnaire has the potential to measure the feasibility of mobile dietary self-monitoring applications.