• Journal of Korea Port Economic Association
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• v.36 no.4
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• pp.17-30
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• 2020

In the shipping industry, it is essential to engage in the preemptive prediction of freight rate volatility through market monitoring. Considering that freight rates have already started to fall, the loss of shipping companies will soon be uncontrollable. Therefore, in this study, factors affecting the freight rates of bulk carriers, which have relatively large freight rate volatility as compared to container freight rates, were quantified and analyzed. In doing so, we intended to contribute to future shipping market monitoring. We performed an analysis using a vector error correction model and estimated the influence of six independent variables on the charter rates of bulk carriers by Handy Size, Supramax, Panamax, and Cape Size. The six independent variables included the bulk carrier fleet volume, iron ore traffic volume, ribo interest rate, bunker oil price, and Euro-Dollar exchange rate. The dependent variables were handy size (32,000 DWT) spot charter rates, Supramax 6 T/C average charter rates, Pana Max (75,000 DWT) spot charter, and Cape Size (170,000 DWT) spot charter. The study examined charter rates by size of bulk carriers, which was different from studies on existing specific types of ships or fares in oil tankers and chemical carriers other than bulk carriers. Findings revealed that influencing factors differed for each ship size. The Libo interest rate had a significant effect on all four ship types, and the iron ore traffic volume had a significant effect on three ship types. The Ribo rate showed a negative (-) relationship with Handy Size, Supramax, Panamax, and Cape Size. Iron ore traffic influenced three types of linearity, except for Panamax. The size of shipping companies differed depending on their characteristics. These findings are expected to contribute to the establishment of a management strategy for shipping companies by analyzing the factors influencing changes in the freight rates of charterers, which have a profound effect on the management performance of shipping companies.

• Korean Journal of Labor Studies
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• v.24 no.1
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• pp.107-156
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• 2018

This article examines the history of the in - house subcontracting and the stabilization of labor - management relations in the steel industry in Japan. The ratio of in-house subcontract workers among steel workers has increased steadily until the mid-2000s, and about 70% in case of the largest company. In-house subcontracting was used as a strategy of the company to increase the quantity flexibility of employment and to save labor costs. The in-house subcontracting company needed company-specialized skills, and the internal labor market was formed because the rate of full-time workers was high and the turnover rate was low. The in-house subcontractor introduced long-term business relationship with the steel factory by introducing the equipment and materials necessary for the performance of the work, and the factory implemented the productivity improvement policy of the in-house subcontractor, and the win-win relationship between the factory and in-house subcontractor was developed. The trade union did not oppose the idea that the expansion of in-house subcontracting contributed to corporate profits, the stability of employment of the members and maintenance of their working conditions. Since 2000, the steel factory has pursued the transformation of in - house subcontractors into subsidiaries, which has been supported by capital relations. By the way, since the mid-2000s, there has been an increase in the number of regular workers' employment. The major factors are as follows: more strengthened compliance with laws and regulations, the higher quality request of customers, stricter keeping of deadlines, and problem in recruiting of workers at in-house subcontract companies. The wage gap between the factory and in - house subcontracting was less at company B than at company S, and the wage level of in - house subcontracting was about 90% of the factory at company B. The relatively small gap at company B seems to be due to the union's movement of narrowing the gap, low market dominance and unfavorable labor market. The internal labor market has been formed in the in-house subcontracting, and the wage gap is not large, and the possibility of labor disputes is low. Industrial relations are stable in the in-house subcontract company as well as the factory. The stabilization of labor-management relations in the steel industry in Korea is required to reduce the wage gap between the factory and in-house subcontract enterprises by raising productivity and expanding the internal labor market at in-house subcontract enterprises.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.589-600
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• 2020

Effective conservation and management of protected areas require monitoring the settlement of invasive alien species and reducing their dispersion capacity. We simulated the potential distribution of invasive alien plant species (IAPS) using three representative species distribution models (Bioclim, GLM, and MaxEnt) based on the IAPS distribution in the forest genetic resource reserve (2,274ha) in Uljin-gun, Korea. We then selected the realistic and suitable species distribution model that reflects the local region and ecological management characteristics based on the simulation results. The simulation predicted the tendency of the IAPS distributed along the linear landscape elements, such as roads, and including some forest harvested area. The statistical comparison of the prediction and accuracy of each model tested in this study showed that the GLM and MaxEnt models generally had high performance and accuracy compared to the Bioclim model. The Bioclim model calculated the largest potential distribution area, followed by GLM and MaxEnt in that order. The Phenomenological review of the simulation results showed that the sample size more significantly affected the GLM and Bioclim models, while the MaxEnt model was the most consistent regardless of the sample size. The optimal model overall for predicting the distribution of IAPS among the three models was the MaxEnt model. The model selection approach based on detailed flora distribution data presented in this study is expected to be useful for efficiently managing the conservation areas and identifying the realistic and precise species distribution model reflecting local characteristics.

• Korean small business review
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• v.42 no.2
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• pp.69-92
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• 2020

This study is aimed at the growth and development of family businesses that greatly contribute to Korea's economic development, but the specific research purpose is to firstly examine the research trends and current status of Korean family businesses and compare them with those of developed countries such as the United States. Second, I would like to look at the future research for revitalizing Korean family business research. In addition, we intend to contribute to increasing the interest in this field and the number of researchers involved. The research target of this paper is 212 papers published in professional academic journals for 13 years from 2006 to 2018 when family businesses began to be fully researched in Korea, 112 master's and doctoral dissertations (graduate schools), and 324 totals. As a result of empirical analysis, the number of published papers is increasing more than the initial ones, but it has been on the decline recently. In addition, 57.5% of the journals are papers that do not have specific definitions or simply list the claims of several scholars by analyzing content. Thesis was 33.9%. As for the type of research, qualitative research, which is a conceptual research, is a small number, and empirical research occupies most of the research topics. Research topics and academic dissertations also have a large proportion of management, management strategy, succession, financial accounting, and business performance. In other words, it can be said that the research on family business in Korea corresponds to the early childhood of the United States. First of all, in the future, we need to put more effort into increasing the qualitative research, starting with the definition of a family business, which is an essential problem, in addition to the theory building of family business. Second, as an analysis level of research, we should make family an important level of analysis for existing individuals, groups, and organizations. Third, the research subject and research area should be expanded. It is desperately necessary to study large companies including chaebols, mainly from small and medium-sized companies, which are the existing research areas of family business. In addition, it is considered that it is necessary to appropriately introduce various theories suitable for the interdisciplinary study, which is the characteristic of the family business, for example, theories of family science, psychology, and sociology. Fourth, it should build the research infrastructure.

• Journal of Life Science
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• v.32 no.4
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• pp.325-330
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• 2022

While swimming is a very popular competitive sports activity, swimming injuries are unique due to the repetitive nature of the swimming stroke and demanding training programs that can result in upper limb overuse. Therefore, the primary objective of this review was to analyze swimmers' injury areas, injury types by stroke type, and swimming rehabilitation, as well as to discuss safety management for improving swimming performance. In this study, the injuries incurred in swimming events were discussed in the order of upper limb injuries (neck, shoulder, arm, and wrist), lower limb injuries (knee and ankle), and waist injuries. An analysis by stroke type found that shoulder injuries occurred most often with freestyle, backstroke, and butterfly strokes, followed by rotator cuff injury, impingement syndrome, and SLAP (superior labral tear from anterior to posterior) lesions. Knee injuries were associated with the breaststroke, whereas spinal cord injuries occurred with the breaststroke and butterfly stroke. Finally, back injuries were associated with the butterfly stroke. During the freestyle stroke, the shoulder undergoes repetitive overhead movement; hence, shoulder and musculoskeletal pain are the most common and well-documented complaints of swimmers. For safety management, coaches and instructors must ensure that athletes do sufficient warm-up and cool-down exercises to avoid injuries. In case of an injury, they should be familiar with first aid measures so that secondary damage can be prevented with its quick application. In addition, coaches and instructors need to be trained in injury prevention and treatment so that they can provide appropriate rehabilitation treatment for athletes. Although swimming-related injuries cannot be completely eliminated, to reduce them to a minimum, leaders need the knowledge to apply scientific and systematic training principles and methods individualized for each athlete.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.145-158
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• 2023

Constructed wetlands (CWs) are effective technologies for urban wastewater management, utilizing natural physico-chemical and biological processes to remove pollutants. This study employed a bibliometric analysis approach to investigate the progress and future research trends in the field of CWs. A comprehensive review of 100 most-recently published and open-access articles was performed to analyze the performance of CWs in treating wastewater. Spain, China, Italy, and the United States were among the most productive countries in terms of the number of published papers. The most frequently used keywords in publications include water quality (n=19), phytoremediation (n=13), stormwater (n=11), and phosphorus (n=11), suggesting that the efficiency of CWs in improving water quality and removal of nutrients were widely investigated. Among the different types of CWs reviewed, hybrid CWs exhibited the highest removal efficiencies for BOD (88.67%) and TSS (95.67%), whereas VSSF, and HSSF systems also showed high TSS removal efficiencies (83.25%, and 78.83% respectively). VSSF wetland displayed the highest COD removal efficiency (71.82%). Generally, physical processes (e.g., sedimentation, filtration, adsorption) and biological mechanisms (i.e., biodegradation) contributed to the high removal efficiency of TSS, BOD, and COD in CW systems. The hybrid CW system demonstrated highest TN removal efficiency (60.78%) by integrating multiple treatment processes, including aerobic and anaerobic conditions, various vegetation types, and different media configurations, which enhanced microbial activity and allowed for comprehensive nitrogen compound removal. The FWS system showed the highest TP removal efficiency (54.50%) due to combined process of settling sediment-bound phosphorus and plant uptake. Phragmites, Cyperus, Iris, and Typha were commonly used in CWs due to their superior phytoremediation capabilities. The study emphasized the potential of CWs as sustainable alternatives for wastewater management, particularly in urban areas.

• Journal of Intelligence and Information Systems
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• v.28 no.1
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• pp.263-286
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• 2022

This study acquires NBA statistical information for a total of 32 years from 1990 to 2022 using web crawling, observes variables of interest through exploratory data analysis, and generates related derived variables. Unused variables were removed through a purification process on the input data, and correlation analysis, t-test, and ANOVA were performed on the remaining variables. For the variable of interest, the difference in the mean between the groups that advanced to the playoffs and did not advance to the playoffs was tested, and then to compensate for this, the average difference between the three groups (higher/middle/lower) based on ranking was reconfirmed. Of the input data, only this year's season data was used as a test set, and 5-fold cross-validation was performed by dividing the training set and the validation set for model training. The overfitting problem was solved by comparing the cross-validation result and the final analysis result using the test set to confirm that there was no difference in the performance matrix. Because the quality level of the raw data is high and the statistical assumptions are satisfied, most of the models showed good results despite the small data set. This study not only predicts NBA game results or classifies whether or not to advance to the playoffs using machine learning, but also examines whether the variables of interest are included in the major variables with high importance by understanding the importance of input attribute. Through the visualization of SHAP value, it was possible to overcome the limitation that could not be interpreted only with the result of feature importance, and to compensate for the lack of consistency in the importance calculation in the process of entering/removing variables. It was found that a number of variables related to three points and errors classified as subjects of interest in this study were included in the major variables affecting advancing to the playoffs in the NBA. Although this study is similar in that it includes topics such as match results, playoffs, and championship predictions, which have been dealt with in the existing sports data analysis field, and comparatively analyzed several machine learning models for analysis, there is a difference in that the interest features are set in advance and statistically verified, so that it is compared with the machine learning analysis result. Also, it was differentiated from existing studies by presenting explanatory visualization results using SHAP, one of the XAI models.

• Asia Marketing Journal
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• v.13 no.3
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• pp.79-102
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• 2011

Researchers in channel dyads have devoted much attention to relationship between interdependence (i.e. interdependence enymmetry and total interdependence) and conflict that promote channel performance. In social science, in spite of the inconsistent results in marketing practice, there are two contradictory theories explain the relationship between interdependence and conflict - bilateral deterrence theory and conflict spiral theory. The authors apply these theories to co-marketing alliance situation in terms that this relationship is also incorporated both company's dependence, either from one company's perspective or each partner about its respective dependence. Using survey data and archival data from 181 companies enlisted in a telecommunication membership program, the authors find out the relationship between interdependence and conflict as well as investigate the antecedents of interdependence - transaction age, transaction frequency, the numbers of alliance partner, and co-marketing alliance specific assets according to previous researches. Using PLS analysis, the authors demonstrate that, with increasing total interdependence in a telecommunication membership program, two co-marketing partners' conflict level is increased in accord with the author's conflict spiral theory predictions. As expected, higher interdependence asymmetry has negative value to level of conflict even though this result is not statistically significant. Other findings can be summarized as follows. In the perspective of telecommunication company, transaction age, transaction frequency, and co-marketing alliance specific assets have influence on its dependence on a partner as independent variables. To the contrary, in a partner's perspective, transaction frequency, co-marketing alliance specific assets and the numbers of alliance partner have significantly impact on its dependence on a telecommunication company. In direct effect analysis, it is shown that transaction age, frequency and co-marketing alliance specific assets have direct influence on conflict. This results suggest that it is more useful for a telecommunication company to select a co-marketing partner which is frequently used by customers and earned high rates of mileage. In addition, the results show that dependence of a telecommunication company on a co-marketing partner is more significantly effected to co-marketing alliance conflict than partner's one. It provide an effective conflict management strategy to a telecommunication company for controling customer's usage rate or having the co-marketing partner deposit high level of alliance specific investment (i.e. mileage). To a co-marketing partner of telecommunication company, it is required control the percentage of co-marketing sales in total sales revenue or seek various co-marketing partners in order for co-marketing conflict management. The research implications, limitation and future research of these results are discussed.

• Korean small business review
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• v.39 no.1
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• pp.1-39
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• 2017

The first generation of the business that had been founded in 1960~1970s faces the situation to consider the succession of the family business developed by devotion of their whole lives in the critical timing to the next generation. In the process of selecting the party of family business succession, it is required to consider a variety of succession types including smooth transfer to the other family member or the employee of the company, selling the company, or hiring external specialist. Foreign countries acknowledge the importance of the succession in the family owned company to perform multiple studies on the influential factors to the succession, distinction, and types of family business succession; and they utilize the results for the related policy development and the support of family owned business succession. However, few studies have been conducted on the succession of the domestic family owned business and majority of them are related to the types of succession. Considering its share and influential power in the domestic economy, it is necessary to develop the guideline and the policies to solve many issues on the succession of the family owned business by systemic studies. Hence, the impact of the main characteristics in the family owned business on the types of its succession was analyzed in this study focusing on five domains of Socioemtional Wealth (SEW) in view of Behavioral Agency Theory by Gomez-Mejia et al. (2007) using the data from 540 family owned small-to-medium sized businesses so as to analyze the issues on their business succession. Upon the empirical analysis results, it was confirmed that they were influenced to the selection of succession type by family succession > internal employee succession > external succession, for the variables of social contribution which were non-financial characteristics, internal employee succession > family succession > external succession for the intellectual properties, and family succession > external succession for the management participation of the family. The distinction of social contribution were influenced the most to the selection of the succession types. Financial factors, business performance, and R&D investment variables were not significantly influenced to their selection of the succession types. In case of simultaneous management, the family succession rate was high and it showed the control effect to strengthen selecting family owned business with R&D investment, social contribution, and company history variables. The behavioral agency theory used in this study was confirmed with high explanation power on the family owned business succession. The family owned business showed the tendency to maintain SEW, and non-financial factors such as accumulated know-how and social contribution based on the long term history were significantly affected to the succession in the small-to-medium sized family owned businesses, unlike general large sized listed companies. The results of this study are expected to be helpful practically for the succession of the family owned business and to suggest the guideline for the development of governmental policy.

• Journal of Korea Water Resources Association
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• v.56 no.12
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• pp.993-1003
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• 2023

Due to the increasing greenhouse gas emissions, the global mean temperature has risen by 1.1℃ compared to pre-industrial levels, and significant changes are expected in functioning of water supply systems. In this study, we assessed impacts of climate change and instreamflow management on water supply reliability in the Geum River basin, Korea. We proposed univariate climate response functions, where mean precipitation and potential evaporation were coupled as an explanatory variable, to assess impacts of climate stress on multiple water supply reliabilities. To this end, natural streamflows were generated in the 19 sub-basins with the conceptual GR6J model. Then, the simulated streamflows were input into the Water Evaluation And Planning (WEAP) model. The dynamic optimization by WEAP allowed us to assess water supply reliability against the 2020 water demand projections. Results showed that when minimizing the water shortage of the entire river basin under the 1991-2020 climate, water supply reliability was lowest in the Bocheongcheon among the sub-basins. In a scenario where the priority of instreamflow maintenance is adjusted to be the same as municipal and industrial water use, water supply reliability in the Bocheongcheon, Chogang, and Nonsancheon sub-basins significantly decreased. The stress tests with 325 sets of climate perturbations showed that water supply reliability in the three sub-basins considerably decreased under all the climate stresses, while the sub-basins connected to large infrastructures did not change significantly. When using the 2021-2050 climate projections with the stress test results, water supply reliability in the Geum River basin was expected to generally improve, but if the priority of instreamflow maintenance is increased, water shortage is expected to worsen in geographically isolated sub-basins. Here, we suggest that the climate response function can be established by a single explanatory variable to assess climate change impacts of many sub-basin's performance simultaneously.