• Journal of KIISE:Software and Applications
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• v.36 no.5
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• pp.353-360
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• 2009

Software, once developed, has a long life and evolves through numerous additions and modifications because of the faults, the changes in user requirements, the changes in environments, and so forth. With the evolution of the software, assuring the quality of the software is getting more difficult because of numerous versions of the software. Meanwhile, regression testing has been used to support the software testing activities and assure acquiring appropriate quality through several versions of software. Regression testing, however, is too expensive because it requires lots of test cases executions and the number of test cases increases sharply as the software evolves. For this reason, several techniques are suggested to help conducting regression testing then test case prioritization technique is understood the most effective and efficient technique to support regression testing. In this paper, we propose an approach, Historical Value-Based Approach, which is based on the use of historical information to estimate the current cost and fault severity for cost-cognizant test case prioritization. As a result of the proposed approach, software testers who perform regression testing prioritize their test cases more effectively so that the test effectiveness of them can be improved in terms of APFDc.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1260-1269
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• 2011

The purpose of this study was to determine postoperative quality of life(QoL), thyroid specific symptoms(TSSs), self care compliance, anxiety and depression in patients with papillary thyroid cancer and to identify factors influencing their postoperative QoL. 154 patients were surveyed using structured questionnaires and data were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation, and multiple regression with SPSS/WIN 18.0 program. The mean score of postoperative QoL in the subjects was 2.72 and the postoperative QoL score of social/family well being subscale showed the lowest score. Most of the subjects suffered from TSSs such as fatigue, cold intolerance, and mood swings. The most frequent activity for self care compliance was taking thyroid hormone(100%) and OPD follow up was the second activity(99.4%). Anxiety score was 45.3 indicating a medium level however 63% of the subjects were evaluated as depression status. Postoperative QoL in thyroid papillary cancer patients showed significantly negative correlations to TSSs, anxiety, and depression (r=-.573, p<.001; r=-.739, p<.001; r=-.742, p<.001). The factors influencing postoperative QoL were TSSs, anxiety, and depression, which explained about 64.9% of the variance. Thus to improve postoperative QoL in patients with papillary thyroid cancer, health care providers should relieve negative emotions related to long term cancer management, develop the support system and provide practical information to apply patients' physical, and psychological symptoms control.

• Journal of Distribution Science
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• v.13 no.11
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• pp.69-77
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• 2015

Purpose - Economic status at an early stage of life after one's retirement is often determined by the long-term sacrifice of one's earlier consumption tendencies. In general, the first and foremost way to secure income after retirement is through annuity savings. People sign up for personal annuity savings in order to guarantee a stable economic life upon retirement, and such actions may be heavily influenced by self-efficacy. Confidence in current economic activity is a source of rational decision-making. Inability to achieve self-control can lead to reckless spending and the eventual hindering of proper investment for the future. This paper examines how self-efficacy and self-control affect the intention and action of enrolling in an annuity savings plan in relation to one's level of financial literacy. Research design, data, and methodology - To analyze the proposed model, this study investigates financial consumers over the age of 20. The data were collected from 511 respondents and analyzed with SPSS 21.0 and AMOS 21.0. First, for the one-dimensional test and to measure the convergent validity of each structure, we use the scale purification process. The results of the test and the confirmatory factor analysis ensure the focus of the validity of the single dimension for each structure. In addition, the validity of the measurement was guaranteed from the results of correlation analysis. Results - First, self-efficacy and self-control have positive effects on the purchasing intention of the personal annuity savings plan. Second, purchasing intention positively affects purchasing behavior. Lastly, self-control has a positive effect on purchasing intention among the low financial literacy group, whereas self-efficacy does not have this effect in the high financial literacy one. Conclusions - The time of product benefit is different with age. The younger group would be granted the savings after several decades once they enroll, whereas the older group would wait for a relatively shorter period of time. Therefore, further research should be conducted in order to verify such a difference. However, this study has value through its confirmation that the roles of self-efficacy and self-control play a part in leading to the enrollment in annuity savings plans and by verifying different effects based on levels of financial literacy. Such results suggest a number of implications in a real life setting. First, banks need to put greater emphasis on the stability of annuity savings in general. Second, customers with relatively low levels of financial literacy are able to control their finances through annuity savings, but find self-efficacy difficult due to a lack of financial understanding. Therefore, such customers should be approached from an invest-effectiveness comparison method. Third, customers with high financial literacy tend to put more value in rational economic decision-making and behavior than in self-efficacy. Therefore, such customers should be approached by promoting the reliability of annuity savings and the excellence of the specific bank's annuity savings plan in comparison to those of other financial institutions.

• Transactions of the Korean hydrogen and new energy society
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• v.6 no.2
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• pp.53-63
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• 1995

A 100kW class stack consisting of 10 molten carbonate fuel cells has been fabricated. Internally manifold stack has been tested for endurance. Each cell in the stack had an electrode area of $100cm^2$ and reactant gases were distributed in each cells in a cross-flow configuration. Initial and long term operation performance of the stack was investgated as a function of gas utilization using a specially designed small scale stack test facility. It was possible to have a stack with an output of more than 100W using an anode gas of 72% $H_2/18%$ $CO_2/10%H_2O$ and cathode gas of 33% $O_2/67%$ $CO_2$ and 70% Air 30% $CO_2$. The output and voltage of the stack at a current 15A($150mA/cm^2$) and gas utilization of 0.4 showed 125.8W and 8.39V respectively by elapsed time of 310 hours operation. In long term operation characteristics, the voltage drop of 52.4mV/1000hour was observed after more than 1,840 hours operation. Among the voltage drop, the OCV loss was highest than other voltage loss such as internal resistance and electrode polarization. Non uniformity of 2voltages and degradation of cell voltage in the stack was observed in according to changing the utilization rate after a long term operation. Further work for increasing the performance prolonging the life of the stack are required.

• Journal of Korean society of Dental Hygiene
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• v.17 no.5
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• pp.791-803
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• 2017

Objectives: Oral health management is important to improve the quality of life among the elderly. This study investigated the performance of elderly oral health management among some care workers in long-term-care hospitals. Methods: The study subjects were 174 care workers in 10 long-term-care hospitals. Data on general characteristics of care workers, attitude, recognition and knowledge of elderly health, performance of elderly oral health management were collected by a self-administered questionnaire. Data were analyzed through descriptive analysis, t-test, ANOVA, correlation and multiple regression analysis by using a SPSS version 23.0 statistical program. Results: The performance score of oral health management was $4.34{\pm}0.64$ on the 5-point Likert scale. The subjects who exercised more than 2 times a month were significantly higher in their performance of elderly oral health management compared to subjects who did not exercise (${\beta}=0.232$, p=0.035). And, the subjects who cared 10-19 persons were significantly higher in performance of elderly oral health management compared to subjects who cared more than 20 elderly (${\beta}=0.246$, p=0.020). The oral health behavior of care worker (${\beta}=0.271$, p<0.001) and the knowledge of oral health care (${\beta}=0.055$, p=0.008) were positively related to the performance of elderly oral health management. Conclusions: The educational program designed to improve knowledge of care workers in accordance with the standard textbook for training care workers should be developed, and the long term education program should be reinforced to improve the performance for elderly oral health care. If care workers can care a proper number of old persons, they will give oral health care to them.

• Journal of Welding and Joining
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• v.30 no.6
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• pp.74-79
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• 2012

It depends on the joint configuration, dimensions and constraints of the joint whether the residual stress at the root of single-sided butt weld is tensile or not. Therefore, recommendation is generally made that high R ratio should be used in the fatigue test of welded joint in order to prevent excessively long life caused by compressive residual stress. In this research, the residual stress profile in butt weld joint was obtained through compliance method, using successive extension of a slot and measurement of the variation of strain during the slot extension. The residual stress profile was firstly assumed to be the linear summation of Legendre polynomials up to 9th order excluding 0th and 1st order. Strain variation on the surface was measured while the slot was being extended by cutting to find out the 8 unknown coefficients of each polynomial term. The cut was made by the electric discharge machine. It was concluded that the residual stress near the surface is positive valued, however, it turned into the negative value as soon as it passed through 2 or 3 mm of the depth.

• Corrosion Science and Technology
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• v.17 no.2
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• pp.74-80
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• 2018

The electronic industries require environmentally-friendly and highly functional materials to enhance the quality of human life. Home appliances require insect repellent steels that work to protect household microwave ovens from incurring damage by insects such as fire ants and cockroaches in tropical regions. Thus, POSCO has developed new types of functional steels, coated with an array of organic-inorganic hybrid composites on the steel surface, to cover panels in microwave ovens and refrigerators. The composite solution uses a fine dispersion of hybrid solution with polymeric resin, inorganic and a pyrethroid additive in aqueous media. The hybrid composite solution coats the steel surface, by using a roll coater and is cured using an induction curing furnace on both the continuous galvanizing line and the electro-galvanizing line. The new steels were evaluated for quality performances, salt spray test for corrosion resistance and biological performance for both insect repellent and antimicrobial activity. The new steels with organic-inorganic composite coating exhibit extraordinarily biological functionalities, for both insect repellent and antimicrobial activities for short and long term tests. The composite-coating solution and experimental results are discussed and suggest that the molecular level dispersion of insecticide on the coating layer is key to biological functional performances.

• Korean Journal of Ecology and Environment
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• v.45 no.4
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• pp.420-443
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• 2012

An Individual-Based Model (IBM) was developed by employing natural and toxic survival rates of individuals to elucidate the community responses of benthic macroin-vertebrates to anthropogenic disturbance in the streams. Experimental models (dose-response and relative sensitivity) and mathematical models (power law and negative exponential distribution) were applied to determinate the individual survival rates due to acute toxicity in stressful conditions. A power law was additionally used to present the natural survival rate. Life events, covering movement, exposure to contaminants, death and reproduction, were simulated in the IBM at the individual level in small (1 m) and short (1 week) scales to produce species abundance distributions (SADs) at the community level in large (5 km) and long (1~2 years) scales. Consequently, the SADs, such as geometric series, log-series, and log-normal distribution, were accordingly observed at severely (Biological Monitoring Working Party (BMWP<10), intermediately (BMWP<40) and weakly (BMWP${\geq}50$) polluted sites. The results from a power law and negative exponential distribution were suitably fitted to the field data across the different levels of pollution, according to the Kolmogorov-Smirnov test. The IBMs incorporating natural and toxic survival rates in individuals were useful for presenting community responses to disturbances and could be utilized as an integrative tool to elucidate community establishment processes in benthic macroin-vertebrates in the streams.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.1
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• pp.96-102
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• 2012

The current establishment of car engineering plastic piping polyethylene (PE) tube used as bonding state or part of the health or safety of fusion is very important. A part of these fusion methods to determine the soundness of the short-term trials and long-term tests can be largely classified. Typical tests included short-term strength, tensile strength, impact strength, compressive strength, resiliency and compression. Polyethylene (PE) pipes installed in the domestic terms of overall penetration rate of 45% has been used. However, polyethylene (PE) pipes have reliability problems, and these occurs mostly in part by defective welding. Therefore, the test is necessary for safety. Non-destructive methods (ultrasonic testing) are difficult to be used. Therefore, Polyethylene (PE) pipe are used. Fusion of thses materilas is necessary in these field however, its technical, and basic research has not been studied well. In this research, short-term strength of welding parts, its tensile strength, hardness, fatigue, and microstructure have been analyzed to find the optimum process conditions to improve mechanical properties.

• The Korean Journal of Rehabilitation Nursing
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• v.7 no.2
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• pp.140-148
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• 2004

Purpose: This study was conducted to identify the relationships of self-esteem, health status and self-care, and compare them between the rural and urban elderly. Method: The subjects were 126 persons with age over 65: rural(69 persons) and urban(57 persons). The data was collected from 1st Sep to 10th Oct, 2004 by questionnaires, and was analyzed with t-test, ANOVA, Least Significant Difference and Pearson's correlation coefficient in the SPSS-Win 10.0. Results: The level of self-esteem, health status and self-care of the elderly in rural were lower than those of the elderly in urban. The higher group self-esteem in the rural elderly shows more health status and self-care than the lower group. Significant differences between two groups in the urban elderly were not found. Self-esteem, health status and self-care were positively correlated each other in the rural elderly. Significant correlations were found between self-esteem and health status, and between self-esteem and self-care in the rural elderly. Conclusion: Self-esteem forms the foundation of psychosocial health and provides a measure for the quality of life of the elderly in long term care. As nursing is in a unique position to promote self-esteem, the nurse can plan and provide nursing intervention with the consideration of characteristics of the rural and urban elderly to promote the self-esteem, health status and self-care of the elderly.