• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.7
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• pp.20-28
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• 2007

This paper describes an analytical method to determine the short-term ratings to reliably operate the overhead transmission lines with double-circuit lines when faulting one circuit of the two. As linearizing the thermal equilibrium equation that represents the temperature characteristic of conductors, we show that the linear equation can be easily represented the over-current and it's temperature property during overloading the one line. Generally, it is well hewn that the short-term line ratings should be determined by considering both conductor life and dip. However, most power companies have their own different guides for the short-term ratings. Using the suggested method in this paper, it can be re-accessed the short-term ratings given in Kepco's overhead transmission lines constructed during the past three different periods. As a result, it is verified that the short-term ratings could be increased mil efficiently. Furthermore, it would be directly applied the given method to determine the short-term dynamic line ratings when occurring faults in one of the double-circuit lines, without doing my other actions for the current lines.

• Journal of Information Processing Systems
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• v.17 no.4
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• pp.707-720
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• 2021

To improve the accuracy of the recommendation system, multi-criteria recommendation systems have been widely researched. However, it is highly complicated to extract the preferred features of users and items from the data. To this end, subjective indicators, which indicate a user's priorities for personalized recommendations, should be derived. In this study, we propose a method for generating recommendation candidates by predicting multi-criteria ratings from reviews and using them to derive user priorities. Using a deep learning model based on convolutional neural network (CNN) and bidirectional long short-term memory (BiLSTM), multi-criteria prediction ratings were derived from reviews. These ratings were then aggregated to form a linear regression model to predict the overall rating. This model not only predicts the overall rating but also uses the training weights from the layers of the model as the user's priority. Based on this, a new score matrix for recommendation is derived by calculating the similarity between the user and the item according to the criteria, and an item suitable for the user is proposed. The experiment was conducted by collecting the actual "TripAdvisor" dataset. For performance evaluation, the proposed method was compared with a general recommendation system based on singular value decomposition. The results of the experiments demonstrate the high performance of the proposed method.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.1
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• pp.133-144
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• 2017

This study investigates firm-specific financial variables that determine investment or speculative grades from the viewpoint of firms, which are one of the major stakeholders related to the credit rating. We employ an ordered probit model for our analysis with the sample data from 1999 to 2015 for listed firms in the Korean stock markets. For investment grades, operating margin, sales, market-to-book, dividend payment, capital expenditure ratio, and tangible asset ratio have a significantly positive impact on credit ratings. In the subsample for speculative grades, the coefficients of the dividend payment, retained earnings ratio, and capital expenditure ratio are significantly positive while short-term debt ratio and R&D expenditures have a significantly negative impact on credit ratings. For the analysis before and after 2009, when the Credit Information Use and Protection Act was strengthened after the global financial crisis, the coefficients of the capital expenditure ratio, cash ratio, and tangible asset ratio are significantly positive in the subsample for investment grades before 2009, but not significant after 2010. The coefficient of the long-term debt ratio is more significantly negative than that of the short-term debt ratio before 2009, for speculative grades, but short-term debt ratio has a more negative effect on ratings than long-term debt ratio after 2010. Surprisingly, the coefficient of the R&D expenditures is significantly negative in both investment and speculative grades since 2010. Our findings are inconsistent with the conjecture that the increase in R&D expenditures enhances the possibility of creating cash-flow by raising the investment growth opportunity, and thus affects positively the credit rating.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.158-169
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• 2004

A method for predicting the short-term dynamic line ratings in overhead transmission lines using real-time weather forecast data is proposed in this paper. Through some inspections for the 3-hour interval forecasting factors such as ambient temperature, wind speed grade and weather code given by KMA(Korea Meteorological Administration), correlation properties between forecast weather data and actual measured data are analyzed. To use these variable in determining the dynamic line ratings, they are changed into suitable numerical values. Furthermore adaptive neuro-fuzzy systems to improve reliabilities for wind speed and solar heat radiation ate designed It was verified that the forecast weather data can be used to predict the line rating with reliable. As a result it can be possible that the proposed predicting system can be effectively utilized by their anticipation a short-time in advance.

• Journal of IKEEE
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• v.18 no.4
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• pp.442-446
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• 2014

A method for applying emergency ratings to improve the reliability of power supply in ACSR overhead transmission lines is described in this paper. Due to re-regulate power industry, most power companies worldwide as well KEPCO have been searching for only economical strategies without new investment. Power demand was rapidly increasing, however, generation amount did not follow sufficiently. Hence in order to increase the transmission capacity for the existing transmission lines in case of peak load, or contingency in transmission lines, an application method of emergency ratings such as short or long term rating is proposed. If applying long term emergency rating instead of static line rating for the period of a peak load, power transmission can be increased to 10 % or more. Furthermore, it was shown that emergency rating can be effectively used in the contingency of double-circuit transmission lines and/or overload cases.

• Journal of Families and Better Life
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• v.21 no.3
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• pp.29-38
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• 2003

A three-year longitudinal design was employed to ascertain whether different types of behavioral inhibition(i.e. traditional, peer-social) were stable from toddler to preschool age(2-4 year), and whether inhibited temperament and/or parenting style would independently and interactively predict children's subsequent social and behavioral outcomes. At time 1, 113 toddlers (55 males, 58 females) and their mothers were observed in the traditional inhibition paradigm. At time 2, 36 4-year-old children were observed with unfamiliar peers in the nontraditional inhibition paradigm. Maternal ratings of psychological functioning of children and maternal behaviors were also obtained for both time 1 and 2. Results showed that behavioral inhibition was not stable from toddler to preschool age. Maternal authoritative behaviors at age 2 were negatively associated with preschooler's social reticence. Toddler's behavioral inhibition was negatively associated with maternal authoritative behaviors at age 4. In a cross-lag correlation analysis, maternal authoritative behaviors appeared to affect child's behavioral inhibition more strongly than the other way around.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.2
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• pp.193-208
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• 2020

In this study, we investigate the effects of technology innovation investments and employment on credit ratings of very small start-up businesses using the data period of 2009 till 2015 test two hypotheses: asymmetric information hypothesis or competence hypothesis. We use financial and non-financial data of 51,903 observations of 12,028 small businesses from a database of a commercial bank and fixed effects panel models and two-stage instrumental variable models. We find that in the short-run small size startups show lower credit ratings than non-startups, and that both technology innovation activities and employment capability improve their credit ratings. In the long-run, technology innovation investments do not improve their credit ratings of later years while employment capability improve their credit ratings of the subsequent year. In addition, the age of startups improves their credit ratings of the current year and until the subsequent two years while employee productivity, fixed ratio and ROA positively affect their credit ratings for up to three years. However, short-term and overall debt ratios, cost of borrowings and firm-size negatively affect their credit ratings for up to three years. The results of the study on credit ratings suggest that credit rating agencies seem to consider both technology innovation activities and employment capability in the credit ratings of small start-ups as 'competence factors' rather than 'asymmetric information factors' with inefficiency and cost burdens. The results also suggest that we must find ways to reflect properly the severe asymmetric information of the early-stage start-ups, and technology innovation activities and employment capability in the credit rating formula.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.157-165
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• 2018

Companies conduct R&D for continuous development and enhancement of corporate value, and obtain patents as an intangible asset resulting from this process. This study screened 103 medical device firms whose R&D information, patent information, and management performance information were all published to determine how R&D activities and patents affect corporate operational performance. The number of patents, R&D costs, company type and Inno-Biz of the company were set as independent variables, and the companies' sales, intangible assets, operating profit ratios, net profit margins, corporate ratings and profit-related financial ratios were used as dependent variables. The results confirmed that R&D expenditure had negative (-) effects on most indicators, including sales volume, operating profit ratio, and net profit ratio, while it had positive (+) [ED highlight - these are unnecessary if negative and positive are also written out.] effects only on intangible assets. Additionally, domestic patents were found to have negative (-) effects on sales, cash flow ratings, and dropped capital return, and positive (+) effects on net profit growth. Moreover, the business performance variables affected by the company characteristics were sales volume and cash flow ratings. The medical device industry is dominated by small and medium-sized businesses Although research and development activities and patents have been shown to have a negative impact on corporate management in the short term, they are expected to have a positive long-term impact when reflecting the characteristics of the medical device industry that must undergo clinical trials and authorization procedures after R&D.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.20 no.2
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• pp.82-89
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• 2009

Objectives: Children with attention-deficit hyperactivity disorder(ADHD) often have difficulties in social behavior. The aim of this study was to evaluate the effectiveness of a short-term training program for improving social skills, self-perception and attention deficits. Methods: The subjects were nine children diagnosed with ADHD with(or without) other mental disorders using the Diagnostic Interview Schedule for Children(DISC-ADHD) module. Children were given eight sessions of a social skills training program. Parents of children simultaneously participated in their own training which was designed to support their children's generalization of skills. Assessments included child, parent and teacher ratings of social skills, self-perception and attention deficit at baseline and post-treatment. Results: Social skills training led to significant improvements in child-reported measures of self-esteem, in teacher reported measures of social skills, and in parent-reported measures of attention deficit. Conclusion: This study suggests that short-term social skills training programs for children with ADHD may improve their social skills, self-perception and attention deficits.

• Clinics in Shoulder and Elbow
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• v.10 no.2
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• pp.183-189
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• 2007

Introduction: While uncommon, humeral head osteonecrosis is an indication for arthroplasty when the humeral head collapse is advanced. The current authors report the short-term clinical results of 7 hemiarthroplasties to treat humeral head osteonecrosis. Materials and Methods: This study focused on 7 reconstructed shoulders of 5 patients whose humeral head osteonecrosis was treated with hemiarthroplasty. The postulated causes were alcohol-induced (4 cases) and steroidinduced (3 cases). The minimum follow-up was 12 months. This study compared the preoperative and postoperative shoulder pain, range of motion, and ASES scores. The postoperative patient satisfaction was assessed. Results: The level of pain during exercise was reduced from a preoperative average of 7.6 to a postoperative average of 1.9. The range of motion, in terms of forward flexion, abduction, and external rotation, improved from preoperative averages of $105.7^{\circ}$, $80^{\circ}$, and $22.1^{\circ}$ to postoperative averages of $146.6^{\circ}$, $139.3^{\circ}$, and $44.3^{\circ}$, respectively. The ASES scores increased from a preoperative mean of 39.0 to a postoperative mean of 84.1. The patients' ratings of the outcomes were excellent (5 cases) and good (2 cases). Conclusions: These short-term results indicate that hemiarthroplasty is a reliable treatment method for humeral head osteonecrosis improving shoulder pain, range of motion, and patient satisfaction.