• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.163-169
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• 2019

This study examined whether industry-level competition affects excess stock returns because of changes in cash holdings. Competitive inter-company threats increase the possibility of the manager's replacement, and function to induce management to make their best efforts, resulting in the amount and quality of the information provided by the enterprise increasing. Therefore, as competition intensifies, agency problems are reduced and stock returns increase because the company's cash holdings are expected to increase. However, there is a view that firms in industries with severe competition tend to have high information asymmetry because competitors may compete in more favorable positions by using detailed information disclosed by the competing firms. Accordingly, as market competition intensifies, the excess stock returns resulting from increased cash holdings are expected to decline. These results show that excess stock returns because of increases in cash holdings increase as the degree of competition in the industry intensifies, thus supporting the positive effect of market competition. Overall, the results of this study provide an understanding that market competition plays an effective external governance mechanism and that investors positively evaluate the cash held by companies with severe industry competition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.155-162
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• 2019

Recent changes in corporate environment, both internal and external, have led to permanent restructuring, which has left baby boomers facing a serious threat to their jobs due to an unprepared involuntary retirement. In line with this period of time, resilience has become important in terms of overcoming the psychological hardships of retirement. In response, the study conducted a study on the effect of resilience on career path conversion among involuntary retirees of baby boomers. The effect on career conversion on the personal characteristics of baby-boomer retirees has been verified by significant differences in gender and job type. In addition, the results of verification of the effect of recovery elasticity on career path transition confirmed that recovery elasticity has a very significant effect on career path transition, and the positive effect of the positive factors among the lower factors was verified to have a very significant positive effect on situational perception, coping method and support, and it was confirmed that interpersonal ability also has an effect on positive effect. However, the ability to self-control did not have a significant effect. Thus, for baby boomers who have to prepare for career transformation after retirement, the resilience has been proven to be a very necessary ability to overcome their hardships and make successful adaptations, and it is expected that it will be very useful in the course of career transition counseling for baby boomers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.485-496
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• 2019

The current study examined the latent mean analysis and path analysis comparison between male and female groups in the structural relationships among parent-child conversation, peer attachment, satisfaction in teacher at a community child care center, ego-resiliency, self-esteem, and career identity in adolescents who attend a community child care center. For this purpose, 438 adolescents who participated in the 4th(2017) questionnaire in the 2nd child panel of the community child care center were used. From the analysis results, first, peer attachment and satisfaction in teacher at a community child care center increased ego-resiliency and career identity, but parent-child conversation did not predict ego-resiliency and career identity. Peer attachment and satisfaction in teacher at a community child care center was fully mediated by ego-resiliency and self-esteem to career identity. Second, in the latent mean analysis, male students showed significantly higher latent mean values in ego-resiliency and self-esteem than female students, while female students showed significantly higher latent mean values in parent-child conversation than male students. Third, multi-group analysis revealed different paths to career identity between the genders. Peer attachment can buffer the effect of ego-resiliency and self-esteem on career identity of male students, but satisfaction in teacher at a community child care center buffers more on the ego-resiliency of female students. The results of this study suggest that social support for enhancing ego-resiliency and self-esteem is needed to encourage career identity, and that gender needs to be considered.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.2
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• pp.15-23
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• 2019

High temperature superconducting (HTS) generators for wind power systems are attractively researched with the advantages of high efficiency and smaller size compared with conventional generator. However, the HTS generators have high Lorentz force problem, which acts on HTS field coils due to their high current density and magnetic field. This paper deals with characteristic analysis of the modularized HTS field coil for a 750 kW superconducting wind power generator according to field coil structure. The modularized HTS field coil structure was designed based on the electromagnetic and mechanical analysis results obtained using a 3D finite element method. The electromagnetic force of the module coil was also analyzed. As a result, the perpendicular and maximum magnetic fields of the HTS coils were 2.5 T and 3.9 T, respectively. The maximum stress of the supports was less than the allowable stress of the glass-fiber reinforced plastic material, and displacement was within the acceptable range. The design specifications and the results of the HTS module coil structure can be effectively utilized to develop large-scale superconducting wind power generators.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.218-226
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• 2018

The purpose of this study was to examine the validity and reliability of the Korean version of the nursing students' perception of instructor caring (NSPIC) scale developed by Wade and Kasper for nursing students. We collected data from 219 nursing students in the 3rd to 4th year at three nursing colleges from June 4 to June 20, 2018. Data were analyzed using SPSS 21.0 and AMOS 21.0. An exploratory factor analysis with varimax rotation was performed, resulting in five factors (respectful sharing, confidence through caring, control versus flexibility, supportive learning climate, appreciation of life's meanings) with a total of 27 items. Confirmatory factor analysis supported good convergent and discriminant validities. In addition, the concurrent validity test confirmed that the K-NSPIC scale was a validity tool as the correlation of the clinical learning environment (CLE) scale appeared as r=.64 (p<.001). The Cronbach's alpha coefficient of the K-NSPIC was .88, and Cronbach's alpha coefficient for each of the five factors was .91, .86, .80, .76, and .85; internal consistency was confirmed. It is significant that the K-NSPIC proved applicable as a useful tool for assessing instructor caring. It is also expected that it will assist in the design of programs to improve the caring ability of instructors.

• The Korean Journal of Applied Statistics
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• v.34 no.5
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• pp.745-760
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• 2021

Prediction of a stock price has been a subject of interest for a long time in financial markets, and thus, many studies have been conducted in various directions. As the efficient market hypothesis introduced in the 1970s acquired supports, it came to be the majority opinion that it was impossible to predict stock prices. However, recent advances in predictive models have led to new attempts to predict the future prices. Here, we summarize past studies on the price prediction by evaluation measures, and predict the direction of stock prices of Samsung Electronics, LG Chem, and NAVER by applying various machine learning models. In addition to widely used technical indicator variables, accounting indicators such as Price Earning Ratio and Price Book-value Ratio and outputs of the hidden Markov Model are used as predictors. From the results of our analysis, we conclude that no models show significantly better accuracy and it is not possible to predict the direction of stock prices with models used. Considering that the models with extra predictors show relatively high test accuracy, we may expect the possibility of a meaningful improvement in prediction accuracy if proper variables that reflect the opinions and sentiments of investors would be utilized.

• Journal of the Korean Geosynthetics Society
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• v.18 no.3
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• pp.33-44
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• 2019

Clinker layer is a stratum structure distributed in volcanic area such as Jeju Island. The clinker layers were formed in between the repetitive action of eruption and solidification of lava flows. Since the clinker layer contains a large amount of voids accompanied by the lava gas ejection process, there is a possibility of inducing overall stability of the ground due to the low stiffness and strength of the clinker layer. Therefore, in this study, site investigation was carried out at both ends of the 00 bridge where the clinker layers exist. And, based on the ground survey results, the behavior of shallow foundations was analyzed numerically. In addition, the improved shallow foundation behavior in grouting substitution using the chemical injection method of the clinker layer was compared with the shallow foundation behavior in the ground, and the grouting substitution efficiency of each layer was analyzed. As a result, the bearing capacity, the replacement efficiency and elastic settlement were different according to the presence or absence of the sediment layer. This is because the sediment layer has a lower stiffness and density than the clinker layer.

• Journal of the Korean Geosynthetics Society
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• v.19 no.4
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• pp.21-32
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• 2020

As the global large-scale infrastructure construction market expands, the construction of civil engineering structures in extreme environments such as cold or hot regions is being planned or constructed. Accordingly, the construction of the pile foundation is essential to secure the bearing capacity of the upper structure, but there is a concern about loss of stability and function of the pile foundation due to the possibility of ground deformation in extreme cold and hot regions. Therefore, in this study, a new type of pile foundation is developed to respond with the deformation of the ground, and the ground deformation that can occur in extreme cold and hot region is largely divided into heaving and settlement. The new type of pile foundation is a form in which a cylinder capable of shrinkage and expansion is inserted inside the steel pipe pile, and the effect of the cylinder during the heaving and settlement process was analyzed numerically. As a result of the numerical analysis, the ground heaving caused excessive tensile stress of the pile, and the expansion condition of the cylinder shared the tensile stress acting on the pile and reduced the axial stress acting on the pile. Ground settlement increased the compressive stress of the pile due to the occurrence of negative skin friction. The cylinder must be positioned below the neutral point and behave in shrinkage for optimum efficiency. However, the amount and location of shrinkage and expansion of cylinder must comply with the allowable displacement range of the upper structure. It is judged that the design needs to be considered.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.357-374
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• 2021

This study examined the difference in perception of supervision between supervisors and supervisees of community welfare centers. The survey subjects were 100 social workers working at social welfare centers in Seoul, Busan, and Incheon. The survey subjects were 62% women and 38% men in their 30s. Approximately 98% of supervisors and 88% of supervisees had a college degree or higher. Regarding the total working period of social welfare institutions, 82% of supervisors and 12% of supervisees had five years or more experience. Regarding the perception of the overall supervision between the supervisors and supervisees, the supervisors and supervisees reported a score of 3.79 and 3.46, respectively. In the perception of supervision according to function, in the case of administrative supervision recognition, the supervisors and supervisees reported a score of 3.78 and 3.43, respectively, and in the educational supervision recognition, the supervisors and supervisees reported a score of 3.65 and 3.29, respectively. Regarding supportive supervision perception, the supervisors and supervisees reported a score of 3.94 and 3.67, respectively. As shown in the above results, the difference in the perception of supervisor and supervisee's supervision by function shows that the supervisor's supervision by all functions is higher than that of the supervisee. As a result, such supervisions are relatively low among supervisees who are provided with supervisions than supervisions that are perceived as being provided by supervisors.

• Journal of the Korean GEO-environmental Society
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• v.12 no.3
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• pp.55-61
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• 2011

Song-Do international city is the area developed in large-scale land reclamation. Song-Do area consists of reclamation layer, sedimentary layer(loose silt, soft clay and sand alternating) and residual layer from the ground surface. Therefore, using pile foundation is inevitable to build structures safely. In this area, driven PHC piles have been generally constructed in terms of environmental and economic conditions. As a result of analyzing 4 sites in Song-Do district 5 and 7 recently, the method of driving pile has many problems because of existence of rigid soil in sedimentary layer and installation of more than 30m piles. In this case, when installing piles by drive after pre-boring up to appropriate depth, the results of constructability analysis were very good. And in the economic efficiency, although 4% of construction cost rose, it was a very slight increase in comparison with improvement of workability. In the case of the stability, more than 70% compared to the allowable stress of piles was satisfied through the load test. As a result, when PHC piles is installed in Song-Do district, the proper construction method is that piles are located at bearing layer after boring rigid sand layer.