• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.4
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• pp.368-375
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• 2013

Failure of small bore piping welds is a recurring problem at nuclear power plants. And the socket weld cracking in small bore piping has caused unplanned plant shutdowns for repair and high economic impact on the plants. Consequently, early crack detection, including the detection of manufacturing defects, is of the utmost importance. Until now, the surface inspection methods has been applied according to ASME Section XI requirements. But the ultrasonic inspection as a volumetric method is also applying to enforce the inspection requirement. However, the conventional manual ultrasonic inspection techniques are used to detect service induced fatigue cracks. And there was uncertainty on manual ultrasonic inspection because of limited access to the welds and difficulties with contact between the ultrasonic probe and the OD(outer diameter) surface of small bore piping. In this study, phased array ultrasonic inspection technique is applied to increase inspection speed and reliability. To achieve this object, the 3.5 MHz phased array ultrasonic transducer are designed and fabricated. The manually encoded scanner was also developed to enhance contact conditions and maintain constant signal quality. Additionally inspection system is configured and inspection procedure is developed.

• Korean Journal of Childcare and Education
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• v.10 no.1
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• pp.183-199
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• 2014

The objective of this study was to examine the effects of mother's perfectionism and parenting beliefs on her preschooler's social competence. The participants were 277 mothers residing in Daejeon, Korea. Basic descriptive statistics, Cronbach's ${\alpha}$, t-test, ANOVA, and multiple regression were used for statistical treatment. The results were as follows: First, a mother's perfectionism and parenting beliefs did not differ according to her educational level. One factor of perfectionism, 'holding high standards', alone showed significant difference between highschool graduates and graduate school graduates, the latter's scores being higher than the former's. There were no significant differences in preschooler's social competence by sex or age. However, a few sex and age differences were found in sub-factors of social competence. Girls scored higher than boys on 'showing affection', and 5 year olds scored lower on 'showing affection' and higher on 'leadership' than 3 years olds. Second, a mother's perfectionism and parenting beliefs were able to explain 22.8% of variance in preschooler's social competence, the former showing more predictive power than the latter. Each of the two factors of maternal perfectionism affected five factors of preschooler's social competence in a different manner. 'Holding high standards' of perfectionism positively influenced preschooler's social competence factors such as 'social capability', 'leadership', and 'showing affection', whereas maternal 'fear of failure' had a negative impact on 'showing affection', 'disturbing'(reversed), and 'instability'(reversed). These results were discussed in relation with changes in social atmosphere and value systems, changes in child-rearing behaviors, or the construct and concept of perfectionism itself, It was suggested that these results be utilized in developing parent education programs for preschoolers lacking social competence.

• Journal of Korean Neurosurgical Society
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• v.54 no.2
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• pp.107-111
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• 2013

Objective : We investigated the effectiveness of stereotactic gamma knife Radiosurgery (GKR) for radioresistant brain metastases with the impact upon histology. Methods : Between April 2004 and May 2011, a total of 23 patients underwent GKR for 67 metastatic brain tumors from 12 renal cell cancers, 5 sarcomas and 6 melanomas. The mean age was 56 years (range, 18 to 79 years). Most of the patients were classified as the Radiation Therapy Oncology Group recursive partitioning analysis class II (91.3%). The synchronous metastasis was found in 6 patients (26.1%) and metachronous metastasis in 17 patients (73.9%). We analyzed the local control rate, intracranial progression-free survival (PFS) and overall survival (OS). Results : The mean tumor volume for GKR was 2.24 cc and the mean prescription dose was 19.4 Gy (range, 10 to 24) to the tumor margin. Out of metachronous metastases, the median duration to intracranial metastasis was 3.3 years in renal cell cancer (RCC), 2.4 years in melanoma and 1.1 years in sarcoma (p=0.012). The total local control rate was 89.6% during the mean 12.4 months follow-up. The six-month and one-year local control rate was 90.2% and 83% respectively. Depending on the pathology, the control rate of RCC was 95.7%, sarcoma 91.3% and melanoma 80.5% during the follow-up. The common cause of local failure was the tumor bleeding in melanoma. The median PFS and OS were 5.2 and 8.4 months in RCC patients, 6.5 and 9.8 months in sarcoma, and 3.8 and 5.1 months in melanoma. Conclusion : The GKR can be one of the effective management options for the intracranial metastatic tumors from the radioresistant tumors. The melanoma showed a poor local control rate compared to other pathologies because of the hemorrhage.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.6
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• pp.155-162
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• 2012

When RC (Reinforced Concrete) structures are exposed to sea water, steel corrosion can occur and this leads a degradation of structural performance. Referring the electro-deposition system with sea water from the 1st step research, durability and structural performance are evaluated in coated steel and RC members containing it in the 2nd research. In the durability performance test, Half Cell Potential test is performed and the coated steel is evaluated to have the high resistance to corrosion, which shows only 35% of corrosion velocity in normal (bare) steel. In the structural performance test, tensile strength, adhesive strength, and flexural/shear in RC member are performed. For the electro-deposit coated steel, increasing ratios of 3.2% and 8.8% are evaluated in the test of tensile strength and adhesive strength, respectively. For the structural test in RC member, there is no big difference between RC members with coated and non-coated steel in ultimate load and failure pattern It is evaluated that the chemical compound with $CaCO_3$ and $Mg(OH)_2$ from electro-deposition causes slightly increased structural performance. The electro-deposit coated steel can be more widely applied after performance verification from several tests like fatigue, resistance to impact, and long term-submerging test.

• Journal of Distribution Science
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• v.11 no.4
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• pp.37-49
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• 2013

Purpose - This research identifies the meaning of the core capability level of Car Master and the reason why its service at the Moment of Truth should be demonstrated through empirical cases. It can be seen that this study differs from existing research because it proposes that the recognized core capability level to achieve customer satisfaction should focus on the mediating effect of Moment of Truth quality. This paper examines the effect of Car Master's recognized core capability level on customer satisfaction by using the variables mentioned above. Moreover, this study uses regression analysis to verify that the mediating effect of Moment of Truth quality on Car Master's capability level achieves customer satisfaction. Research design, data, and methodology - First, we present evidence that could apply to Car Master's recognized core capability level by detailing the relationship between customer satisfaction and a structuring factor for Car Master's core capability level. Our proposed research model observes the relationship between the structuring factor of core capability and customer satisfaction. Second, we had an opportunity to define how the core capability and Moment of Truth quality affect customer satisfaction by performing empirical analysis on the partial mediating effect of Moment of Truth quality at a recognized core capability level and Moment of Truth quality affecting customer satisfaction. Results - First, the results indicate that Car Master's recognized core capability level (product professionalism, marketing skill, and reliability) positively affects customer satisfaction. Second, the results show that an ability to listen and a sense of dedication positively affect customer satisfaction, and are among the Moment of Truth quality factors; but performance capability, which is one of the Moment of Truth quality factors, does not positively affect customer satisfaction. These results clearly differ from prior studies focused on Moment of Truth quality and consumer satisfaction. Third, the results show that Moment of Truth quality has a partial mediating effect in terms of the impact of Car Master's recognized core capability level in achieving consumer satisfaction. Conclusions - This research indicates that the company will be able to expand if they investigate and show an interest in more training and education for Car Master. The study verified that outstanding Car Masters show differentiated performance on customer satisfaction at the Moment of Truth in various instances. Thus, we believe that this is the time for a discussion on systematic and empirically recognized core capability levels and the Moment of Truth quality. The study on Car Master's recognized core capability level offers suitable solutions for Car Masters to respond to customers at the Moment of Truth. Further, this study emphasizes the importance of service as a critical factor having a direct relationship with the company's success and failure and contributing to building trust with the customer. Thus, an investment in continuous education and training for Car Master will help the growth of the business.

• Journal of Radiation Protection and Research
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• v.33 no.1
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• pp.1-12
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• 2008

International Standardization in all technical area is gaining its momentum as its impact and implication over global trade is directly linked. The worldwide competition to secure a dominant position in the standardization process is ever growing over the years. In 2005, the International Technical Committee on Nuclear Instrumentation, which is a subunit of International Electro-technical Commission (IEC), was held in Korea under the auspices of MOST (Ministry of Science and Technology). Korea has adopted its Rule and Regulation as the National Standard. As a part of a link to National Mid-and Long-term Atomic Energy R&D Program of MOST, the technical development of a performance test for the radiation monitors was carried out under mechanical environment and electromagnetic immunity conditions. The characteristics of the radiation fields were also evaluated under the conditions and introduced to a techniques of performance test for the radiation protection instrumentation adopted IEC61526 standards and it's results was analyzed. We would like to share the experience gained in these efforts, failure as well as success, and to discuss the problems encountered and serious consideration to be taken into account in the future endeavor.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.245-250
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• 1998

Purpose : This study was to evaluate survival, failure patterns, and prognostic factors of stage I squamous cell carcinoma of the glottic larynx after curative radiation therapy. Materials and Methods : A retrospective analysis was done for 57 patients with glottic cancer who were treated with curative radiation therapy from June 1985 to November 1992. There were 55 male and two female patients. Patients' age ranged from 17 to 71 years(median 39 years). Radiation therapy was delivered five times a week, 2 Gy daily, total 66 Gy using 6 MV X-ray. Results : Complete response(CR) was noted in 51 out of 57 patients (89.5%) and persistent disease (PER) in six out of 57 patients(10.5%). The disease-free survival rates at 3 and 5 years were 72.9% and 63.8%, respectively. Seven failures were observed among 51 CR patients during follow-up. Salvage total laryngectomy for six recurred patients and partial laryngectomy for one recurred patient were done with successful results, i.e., all of them were actually salvaged. Among six PER patients, salvage total laryngectomy for two patients and partial laryngectomy for two patients were done and two patients refused operation. Following salvage surgery for the four PER patients, three were salvaged and one failed locoregionally. Among the 13 failures 10(76.9%) were salvaged with surgery. The ultimate local control rate at 5 years was 92.3% and overall 47 out of 57 (82.5%) patients were able to preserve their larynx. The 5-year disease-free survival rates were 85.5% for posterior lesions, and 61.6% for anterior lesions(P<0.05). Cord mobility, involvement of anterior commissure, field size, and T stage did not impact on disease-free survival. Conclusion : Considering the high percentage of voice preservation with initial radiotherapy, radiotherapy should be the first choice in the treatment of stage 1 glottic carcinoma.

• Fire Science and Engineering
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• v.32 no.1
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• pp.89-98
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• 2018

Fire accidents in foreign countries, like the accident in a thermal power plant in Beijing, the accidents in domestic power plants, including Boryeong Power Plant in 2012 and Taean Power Plant in 2016, a disaster in a nuclear power plant in Fukushima in 2011 or the large-scale power failure in California in 2001 are safety accidents related to electric power, which caused losses in the people's stable lives and the countries. Electricity has an absolute impact on the people's life and the economy, so we can easily expect the serious situation affecting economic growth as well as direct damage to the protection of the people's lives and the losses of properties, if there are fire or explosion accidents or radioactive leak because of negligence in safety management, or problems because of natural disasters like an earthquake in power plants that generate electricity. In this study, it was drawn the improvement of the organizations exclusively in charge of firefighting, the operation of a program for the improvement of professional competency, the development of a customized firefighting management system for plants for systematic firefighting safety management and the improvement of the earthquake-proof correspondence system, which has recently become an issue, as measures for improvements through a survey of the actual conditions concerning the necessity of the construction of a firefighting safety management system for power plants with five power generation companies, including Korea Southern Power Co., Ltd., and the persons in charge of firefighting safety Korea Hydro & Nuclear Power Co., Ltd.

• Korean Journal of Construction Engineering and Management
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• v.17 no.4
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• pp.3-11
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• 2016

Recently, overseas plant orders of domestic enterprises are steadily increased, and the amount of orders in the first half of 2014 were 93% increased compared to the previous year. In addition, now which is the third quarter of 2015, overseas plant orders are already over 249.8 billion dollars so the interests of plant industry research has been increased. In the life cycle of the plant project, CM before the construction stage is to complement the uncertainties that are inherent in the early stages of the project, and from the viewpoint of supporting the rational decision-making, the importance of its role is on the rise. Among them, excavating and investing participation plan in the planning stage is an important work that has a large impact force to influence the success and failure of future project. However, the work has become a problem with frequent consultations due to decision-making, continuous modification, and inefficient repetitive tasks. Therefore, it is needed that work process should be changed to effectively accommodate. The purpose of this paper is to derive the major work items for excavating and investing participation plan in the planning stage of the plant project, and establish a standardized work process through the Delphi analysis. The result of this study is expected to be utilized for EPC companies in ensuring the technical competitiveness in planning on overseas markets, and improve the efficiency of work.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.4
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• pp.85-96
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• 2017

There are many people who start business because of unstable employment due to income polarization. There are many people who start business because of unstable this study is to present the necessary situation and direction for the prospective founders who are hesitant to start their own business by lacking self - confidence and information about Preparing for start-up the purpose of this study is to investigate the effect of pre - founder's psychological characteristics and start - up preparation characteristics on entrepreneurship intention. In order to conduct this study, 144 male and 114 female who were temporary workers and about to retire were analyzed for validity and reliability using 258 questionnaires. As a result of analyzing the adjustment effect of entrepreneurship education as an interaction term in the psychological characteristics and the preparation characteristics of the entrepreneurship, the risk taking tendency and the preparation period for entrepreneurship were significant for entrepreneurship education. In addition, the greater the necessity and importance of entrepreneurship education, the greater the effect on entrepreneurship education. It is a meaningful study that can give confidence to the subjects who want to start a business but are afraid of failure. This study is expected to contribute to the government's start - up policy by analyzing the influence of pre - founders on the intention of start - up.