• Korean Journal of Child Education & Care
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• v.18 no.1
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• pp.1-25
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• 2018

The purpose of this study is to examine if ego resilience has regulating effects in correlation between child care teachers' job stress and work environment and their performance of roles with child care teachers working in Seoul and Incheon. PASW 20.0 was employed to conduct frequency, percentage, and reliability analysis. For each of the study questions, correlation analysis, multiple regression analysis, and stepwise regression analysis were done. The findings of this study are as follows; First, job stress perceived by child care teachers is found to have negative effects on their performance of roles. Second, work environment perceived by child care teachers such as relationship with the director, relationship with fellow teachers, welfare environment, support for teacher expertise, and factors related to operation or decision making are found to influence their performance of roles. Lastly, in correlation between work environment perceived by child care teachers and their performance of roles, ego resilience has regulating effects, and so does it in correlation between job stress and their performance of roles.

• Journal of Korea Port Economic Association
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• v.32 no.2
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• pp.123-135
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• 2016

This study uses Data Envelopment Analysis(DEA) to investigate the management efficiency of Korean shipping companies based on business administration costs such as corporate entertainment, advertisement, and labor costs. We analyze shipping enterprises listed on the Korean stock market of the period of 2010-2014. Corporate entertainment, advertisement and labor costs are used as input variables and sales and net income are used as output variables. We use technical efficiency, pure technical efficiency, scale efficiency and returns to scale to propose a plan to improve the efficiency of inefficiency decision-making units (DMUs). The results of the efficiency analysis show that six of the DMUs in the technical efficiency of CCR model and eight of the DMUs in the pure technical efficiency of BCC model are in efficient state. In terms of return to scale, six of the DMUs(24% of all DMUs) show increasing returns to scale, while 13 DMUs(52% of all DMUs) showdecreasing returns to scale. Because multiple efficient state for DMUs exist in the technical efficiency analysis, we conduct a super efficiency analysis. The results show that the efficient state of the twomost efficient DMUs are 1.314 and 1.243, respectively. This implies that these DMUs could maintain their current levels of the efficiency if they increase the amount spent on advertisements, corporate entertainment and labor costs by 31.4% and 24.3%. respectively. We conclude this study by providing the efficiency states of each DMU and target for improving the inefficiencies in each case.

• Journal of Intelligence and Information Systems
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• v.14 no.1
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• pp.117-129
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• 2008

The cost-based scheduling work has been done in both the Operations Research (OR) and Artificial Intelligence (AI) literature. To deal with more realistic problems, AI-based heuristic scheduling approach with non-regular performance measures has been studied. However, there has been little research effort to develop a full inter-job cost propagation algorithm (CPA) for different jobs having multiple downstream and upstream activities. Without such a CPA, decision-making in scheduling heuristics relies upon local, incomplete cost information, resulting in poor schedule performance from the overall cost minimizing objective. For such a purpose, we need two types of CPAs : intra-job CPA and inter-job CPA. Whenever there is a change in cost information of an activity in a job in the process of scheduling, the intra-job CPA updates cost curves of other activities connected through temporal constraints within the same job. The inter-job CPA extends cost propagation into other jobs connected through precedence relationships. By utilizing the cost information provided by CPAs, we propose cost-based scheduling heuristics that attempt to minimize the total schedule cost. This paper develops inter-job CPAs that create and update cost curves of each activity in each search state, and propagate cost information throughout a whole network of temporal constraints. Also we propose various cost-based scheduling heuristics that attempt to minimize the total schedule cost by utilizing the cost propagation algorithm.

• Asia pacific journal of information systems
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• v.20 no.1
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• pp.33-56
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• 2010

The current business environment has been characterized as less munificent, highly uncertain and constantly evolving. In this environment, the company with dynamic capability is reported to be more successful than others in building competitive advantage. Dynamic capability focuses on the link between a dynamically changing environment, strategic agility, architectural reconfiguration, and value creation. Being characterized to be flexible and adaptive to market circumstance changes, an organization with dynamic capability is described to have high resource fluidity, which represents business process, resource allocation, human resource management and incentives that make business transformation faster and easier. Successful redeployment of the resources for dynamic adaptation requires organizational forms and reward systems to be well aligned with firm's technological infrastructures and business process. The alignment is considered to be an executive level commitment. Building dynamic capability is knowledge driven; relying on new knowledge to reconfigure firm's resources. Past studies established the link between the effective execution of a knowledge-focused strategy and relevant setting of architectural elements such as human resources, structure, process and information systems. They do not, however, describe in detail the underlying processes by which architectural elements are adjusted in coordinated manners to build knowledge-driven dynamic capability. In fact, understandings of these processes are one of the top issues in IT management. This study analyzed how a Korean corporation with a knowledge-focused strategy aligned its architectural elements to develop the dynamic capability and thus create value in the dynamically changing markets. When the Korean economy was in crisis, the company implemented a knowledge-focused strategy, restructured the organization's architecture by which human and knowledge resources are identified, structured, integrated and coordinated to identify and seize market opportunity. Specifically, the following architectural elements were reconfigured: human resource, decision rights, reward and evaluation systems, process, and IT infrastructure. As indicated by sales growth, the reconfiguration helped the company create value under an extremely turbulent environment. According to Ancona et al. (2001), depending on the types of lenses the organization uses, different types of architecture will emerge. For example, if an organization uses political lenses focusing on power, influence, and conflict. the architecture that leverage power and negotiate across multiple interest groups would emerge. Similarly, if an organization uses economic lenses focusing on the rational behavior of organizational actors making choices based on the costs and benefits of action, organizational architecture should be designed to motivate and provide incentives for the actors (Smith, 2001). Compared to this view, information processing perspectives consider architecture to be designed to maximize the capacity of information processing by the actors. Using knowledge lenses, the company studied in this research established architectural elements in a manner that allows the firm to effectively structure knowledge resources to form dynamic capability. This study is revelatory single case with a historic perspective. As a result of this study, a set of propositions and a framework are derived, which can be used for architectural alignment.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.6
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• pp.177-189
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• 2018

Business environment is always full of challenges. Despite various strategic efforts, there are so many failure cases of misfit. With the weaker resource base and institutional foundation, startup firms find it more difficult to find the right spot in the stiff competition. In the middle of evolutionary process, the startup firms need proper strategies meeting the differential challenges along the multiple stages of growth. Following the idea of product life cycle, this study applies the four stages of growth-startup, initial growth, accelerated growth, matured, and decliing. The next step for the startup manager is meeting each stage of growth with proper strategic efforts, including strategy, structure, decision-making pattern, and control method. When the knowledge factor is introduced, there is a potential for higher performance. Based on the 'Detailed Survey on Startup Ventures in 2017,' this study explores the impact of the government subsidy program on the firm competitiveness and performance-along the four stages of growth. In each stage, the strategy factors showed differential impact.

• Journal of Environmental Impact Assessment
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• v.28 no.3
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• pp.201-214
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• 2019

The concept of ecosystem services is important for the effective management of regional ecological resources. Multiple ecosystem services provided by regional ecosystems are represented as ecosystem service bundles, which define the co-occurrent ecosystem services in a specific region. Bundles provide useful information to identify regional characteristics of ecosystem services and categorize sub-regions with similar patterns of ecosystem service provision. We assessed eleven ecosystem services using modeling approaches and statistical data and produced bundles of cities in Gyeonggi-do.We also conducted principal component analysis and cluster analysis to categorize these cities according to the characteristics of ecosystem services. The results indicated that the cities in Gyeonggi-do were categorized into three groups depending on the types of provision,regulation, and cultural services, and were designated as urbanized, urban-forest, agriculture, or forest cities. These groups were influenced by land use patterns reflecting regional social-environmental features. The results provide useful information for identifying regional ecosystem services and facilitate decision-making in regional ecosystem service management.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.967-977
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• 2018

The problems of lack of skilled worker and poor productivity at the construction site continue to be raised, and the introduction of construction automation as one of the solutions to this has been considered. The development of various types of equipment and systems has been carried out, especially for earthwork operations with multiple construction equipment. However, the level of commercialization of developed equipment or systems is very limited. Although the single-product type of earthwork equipment has been applied to the site, the integrated type of earthwork system is still in the field testing stage. Considering these constraints, the limited budget and research period, a strategy is needed to identify which technology areas and core technologies should be developed first. In this study, the technology areas and detailed core technologies that are essential for the development of earthwork systems at the level of commercialization are set and the priority of development is determined. In addition, the earthwork system that has been developed so far is analyzed and the detailed development direction is presented based on it. The findings can be used for a decision making to set the priority for core technologies that should be developed first in the limited budget and period.

• Journal of Society of Preventive Korean Medicine
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• v.23 no.2
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• pp.67-76
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• 2019

Objectives : The publication of systematic reviews (SRs) has increased significantly over the years, and systematic reviews are considered to have the strongest evidence as they are at the top of the hierarchy of evidence pyramid. In this study, a thorough assessment of all SRs published in Journal of Society of Preventive Korean Medicine (JSPKM) was performed to evaluate their reporting quality and methodological quality to better improve the quality of SRs in JSPKM. Methods : JSPKM website was searched to include all SRs published in JSPKM from 1997 to 2018. Two independent researchers assessed the SRs using A MeaSurement Tool to Assess systematic Reviews (AMSTAR, formerly known as Assessment of Multiple Systematic Reviews) tool checklist for methodological quality assessment, and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline checklist for reporting quality assessment. Results : Out of 618 published articles published in JSPKM from 1997 to 2018, only 3 SRs were identified as SRs. For AMSTAR methodological quality scoring, the average score of 3 SRs was 3.0 out of 11 which is low quality level. For PRISMA reporting quality items, the 3 SRs reported 17.3 items on average out of 27 items. The 3 identified SRs did not provide information on protocol or registration which is included in both AMSTAR assessment tool and PRISMA guideline. Conclusions : Improvements on reporting quality and methodological quality of SRs using relevant tools or guidelines are needed to assure the quality of SRs published in JSPKM so that their conclusions will be more transparent and reliable for decision-making in healthcare and the best clinical practice.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.453-459
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• 2021

The system marginal price of electricity is the amount paid to all the generating units, which is an important decision-making factor for the construction and maintenance of an electrical power unit. In this paper, we suggest a long-term forecasting model for calculating the system marginal price based on prices of natural gas and oil. As most variables used in the analysis are nonstationary time series, the long run relationship among the variables should be examined by cointegration tests. The forecasting model is similar to an error correction model which consists of a long run cointegrating equation and another equation for short run dynamics. To mitigate the robustness issue arising from the relatively small data sample, this study employs various testing and estimating methods. Compared to previous studies, this paper considers multiple fuel prices in the forecasting model of system marginal price, and provides greater emphasis on the robustness of analysis. As none of the cointegrating relations associated with system marginal price, natural gas price and oil price are excluded, three error correction models are estimated. Considering the root mean squared error and mean absolute error, the model based on the cointegrating relation between system marginal price and natural gas price performs best in the out-of-sample forecast.

• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.563-573
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• 2022

This work aimed to develop a new equation for turbidity (Turb) simulation and prediction using statistical methods based on principal component analysis (PCA) and multiple linear regression (MLR). For this purpose, water samples were collected monthly over a five year period from Cheurfa dam, an important reservoir in Northwestern Algeria, and analyzed for 12 parameters, including temperature (T°), pH, electrical conductivity (EC), turbidity (Turb), dissolved oxygen (DO), ammonium (NH₄⁺), nitrate (NO₃^-), nitrite (NO₂^-), phosphate (PO₄^3-), total suspended solids (TSS), biochemical oxygen demand (BOD₅) and chemical oxygen demand (COD). The results revealed a strong mineralization of the water and low dissolved oxygen (DO) content during the summer period. High levels of TSS and Turb were recorded during rainy periods. In addition, water was charged with phosphate (PO₄^3-) in the whole period of study. The PCA results revealed ten factors, three of which were significant (eigenvalues >1) and explained 75.5% of the total variance. The F1 and F2 factors explained 36.5% and 26.7% of the total variance, respectively and indicated anthropogenic pollution of domestic agricultural and industrial origin. The MLR turbidity simulation model exhibited a high coefficient of determination (R² = 92.20%), indicating that 92.20% of the data variability can be explained by the model. TSS, DO, EC, NO₃^-, NO₂^-, and COD were the most significant contributing parameters (p values << 0.05) in turbidity prediction. The present study can help with decision-making on the management and monitoring of the water quality of the dam, which is the primary source of drinking water in this region.