• Journal of Industrial Convergence
• /
• v.21 no.1
• /
• pp.55-65
• /
• 2023

The purpose of this study is to explore the teaching experience of first-time youth soccer leaders. To this end, four leaders registered in the U-12 team were selected from those with more than 10 years of player experience, less than 5 years of coaching experience, and a level C or higher of the Korea Football Association leader's license. Accordingly, the analysis categories and analysis units were categorized according to the research problem, and data analysis was conducted through an inductive method. As a result of the study, youth soccer leaders were starting their coaching with the mindset of "I shouldn't" and "I can do it" based on their past experiences. They who concerned their uncertainty about the future in the teaching field were struggling with how to communicate with student and were less professional in teaching and learning ability. but they were trying to gain expertise while feeling rewarded in teaching. Accordingly, it was discussed to improve the treatment of youth soccer leaders and improve the program that is the leader training system.

• Journal of Environmental Science International
• /
• v.32 no.8
• /
• pp.595-611
• /
• 2023

The purpose of this study is to improve the daily prediction results of PM2.5 from the air quality diagnosis and evaluation system operated by the Busan Institute of Health and Environment in real time. The air quality diagnosis and evaluation system is based on the photochemical numerical model, CMAQ (Community multiscale air quality modeling system), and includes a 3-day forecast at the end of the model's calculation. The photochemical numerical model basically has limitations because of the uncertainty of input data and simplification of physical and chemical processes. To overcome these limitations, this study applied DNN (Deep Neural Network), a deep learning technique, to the results of the numerical model. As a result of applying DNN, the r of the model was significantly improved. The r value for GFS (Global forecast system) and UM (Unified model) increased from 0.77 to 0.87 and 0.70 to 0.83, respectively. The RMSE (Root mean square error), which indicates the model's error rate, was also significantly improved (GFS: 5.01 to 6.52 ug/m³ , UM: 5.76 to 7.44 ug/m³ ). The prediction results for each concentration grade performed in the field also improved significantly (GFS: 74.4 to 80.1%, UM: 70.0 to 77.9%). In particular, it was confirmed that the improvement effect at the high concentration grade was excellent.

• Journal of the Korean Geosynthetics Society
• /
• v.22 no.3
• /
• pp.105-117
• /
• 2023

The recent global energy supply crisis has led to increased uncertainty in international energy markets. These market changes lead to a rise in global energy prices and development is expanding to the extreme cold regions (Arctic Circle) where undeveloped energy resources are abundantly stored. Arctic Circle has a special business environment such as natural environment, laws, institutions and culture, research on location evaluation of development areas is necessary in advance. In this study, the spatial information of Alberta, Canada, where non-traditional energy resource development activities have recently been active, was collected and analyzed. In addition, an optimal location evaluation model for resource development was developed using construction environment spatial information data and the reliability is verified by comparing and analyzing the existing resource development areas.

• Architectural research
• /
• v.25 no.3
• /
• pp.41-51
• /
• 2023

Building restoration is a complex process with a high level of uncertainty. Restoration professionals can significantly benefit from the well-established discipline of project management to achieve their targets; however, available evidence shows that the use of the project management body of knowledge in restoration projects is far from the desired level. Several historical organisations have since been established with the goal of preserving and governing cultural identity, and numerous studies have supported the need of preserving architectural heritage. Many owners, investors, academics, and developers believe that it would be considerably more expensive to renovate and restore an old building than to create a new one. Although the project management process is generally recognised, the concept of project management for architectural heritage projects differs due to the uniqueness of each project. It differs from many construction projects in terms of the need for research-based practices to define scope, planning, scheduling, supervision,decision-making,and also performance. The Greco-Roman Museum in Alexandria's planning, design, and building phases are being studied with the aim of identifying and analysing the variables that contribute to project delays. Three project management pillars were established as a result of gathering this data from the project's stakeholders: the first pillar addresses time management for the existing phase and how it will be incorporated into the new extension phase; the second pillar addresses performance in relation to project management issues in the delivery of the best quality of a construction project; and the third pillar addresses the scope of the new extension because it will significantly impact the other two pillars. This paper argues that a contemporary perspective which utilizes project management tools and techniques can contribute to the conservation of architectural heritage in line with the conservation principles.

• Smart Media Journal
• /
• v.11 no.1
• /
• pp.38-45
• /
• 2022

A lot of research is being going until this day in order to obtain stable profit in the stock market. Trading algorithms are widely used, accounting for over 80% of the trading volume of the US stock market. Despite a lot of research, there is no trading algorithm that always shows good performance. In other words, there is no guarantee that an algorithm that performed well in the past will perform well in the future. The reason is that there are many factors that affect the stock price and there are uncertainties about the future. Therefore, in this paper, we propose a model using TimeGAN that predicts future returns well and selects algorithms that are expected to have high returns based on past records of the returns of algorithms. We use TimeGAN becasue it is probabilistic, whereas LSTM method predicts future time series data is deterministic. The advantage of TimeGAN probabilistic prediction is that it can reflect uncertainty about the future. As an experimental result, the method proposed in this paper achieves a high return with little volatility and shows superior results compared to many comparison algorithms.

• Earthquakes and Structures
• /
• v.22 no.5
• /
• pp.503-515
• /
• 2022

This paper presents the development of seismic fragility curves for a precast reinforced concrete bridge instrumented with a structural health monitoring (SHM) system. The bridge is located near an active seismic fault in the Dominican Republic (DR) and provides the only access to several local communities in the aftermath of a potential damaging earthquake; moreover, the sample bridge was designed with outdated building codes and uses structural detailing not adequate for structures in seismic regions. The bridge was instrumented with an SHM system to extract information about its state of structural integrity and estimate its seismic performance. The data obtained from the SHM system is integrated with structural models to develop a set of fragility curves to be used as a quantitative measure of the expected damage; the fragility curves provide an estimate of the probability that the structure will exceed different damage limit states as a function of an earthquake intensity measure. To obtain the fragility curves a digital twin of the bridge is developed combining a computational finite element model and the information extracted from the SHM system. The digital twin is used as a response prediction tool that minimizes modeling uncertainty, significantly improving the predicting capability of the model and the accuracy of the fragility curves. The digital twin was used to perform a nonlinear incremental dynamic analysis (IDA) with selected ground motions that are consistent with the seismic fault and site characteristics. The fragility curves show that for the maximum expected acceleration (with a 2% probability of exceedance in 50 years) the structure has a 62% probability of undergoing extensive damage. This is the first study presenting fragility curves for civil infrastructure in the DR and the proposed methodology can be extended to other structures to support disaster mitigation and post-disaster decision-making strategies.

• Journal of Korea Trade
• /
• v.27 no.1
• /
• pp.1-18
• /
• 2023

Purpose - Using a sample of Korean multinational corporations, we examine whether the relationship between tax risk and the implied cost of capital discriminates between the environmental, social, and corporate governance (ESG) of highly rated firms. Design/methodology - Firms with high tax risks have an increased uncertainty of future cash flows. Therefore, as the volatility of future cash flow increases, information asymmetry and the required return increases. Highly rated ESG firms can reduce information asymmetry, thereby weakening the positive relationship between tax risk and cost of capital. We employ the standard deviation of the cash effective tax rate as proxy of tax risk. We utilize the ESG rating data of the Korea Corporate Governance Service (KCGS). We use a PEG model, MPEG model, and GM model to measure the implied cost of capital. Findings - We find a positive association between the implied cost of capital and tax risk. The positive relationship between tax risk and the implied cost of capital weakens in highly rated ESG firms. Highly rated ESG firms prefer a stable tax position to invest after-tax cash flows into sustainable management. Therefore, the negative effects of tax risk on cost of capital can be reduced. Originality/value - This study provides empirical evidence that ESG activities can mitigate the negative impact of tax risk on the cost of capital for Korean multinational corporations. In a business environment where ESG activities are more important, the empirical results that ESG activities can reduce the corporate risk of Korean FDI companies are expected to provide implications for the ESG activities of multinational corporations.

• Knowledge Management Research
• /
• v.24 no.2
• /
• pp.49-63
• /
• 2023

Existing knowledge regarding the antecedents of the entrepreneurial orientation (EO) of firms is somewhat limited given the emphasis on its performance implications. To address this research gap, this study aims to explore the drivers of entrepreneurial orientation using the resource-based view (RBV) and contingency perspective. To test our hypotheses, this study uses 225 survey data collected from Korean exporters. Results show that the level of entrepreneurial orientation varies depending on organizational characteristics such as firm size and internationalization of the firm. Our findings also support the tenet of the contingency perspective by showing the influences of environmental characteristics such as technological turbulence and market uncertainty on the entrepreneurial orientation of firms. Our empirical research provides academic and practical implications for the field of entrepreneurship.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.12 no.4
• /
• pp.329-340
• /
• 2010

Mechanical behavior of underground cavity construction such as tunnel is very difficult to estimate due to complexity and uncertainty of ground. Prediction of behavior according to excavation of tunnel mainly uses method utilized of model test or numerical analysis. But scale model test is difficult to reappear field condition, numerical analysis is also very hard to seek choice of suitable constituent model and input data. To solve this problem, this paper forecasted the deformation of tunnel that applied to information of crown settlement and convergence, RMR in weathered granite by using the regression analysis. The result of the analysis shows that the crown settlement according to excavation occurs approximately 70~80% of total displacements within about 20 days. As a result of the prediction of crown settlement and convergence, an exponential function becomes more accurate at measurements than an algebraic function. Also this paper got a correlation in comparison of RMR and displacements of 6 sections.

• Journal of Radiation Protection and Research
• /
• v.48 no.2
• /
• pp.90-99
• /
• 2023

Background: Quantitative risk assessments should be accompanied by uncertainty analyses of the risk models employed in the calculations. In this study, we aim to develop a computational code named SUMRAY for use in cancer risk projections from radiation exposure taking into account uncertainties. We also aim to make SUMRAY publicly available as a resource for further improvement of risk projection. Materials and Methods: SUMRAY has two versions of code written in R and Python. The risk models used in SUMRAY for all-solid-cancer mortality and incidence were those published in the Life Span Study of a cohort of the atomic bomb survivors in Hiroshima and Nagasaki. The confidence intervals associated with the evaluated risks were derived by propagating the statistical uncertainties in the risk model parameter estimates by the Monte Carlo method. Results and Discussion: SUMRAY was used to calculate the lifetime or time-integrated attributable risks of cancer under an exposure scenario (baseline rates, dose[s], age[s] at exposure, age at the end of follow-up, sex) specified by the user. The results were compared with those calculated using another well-known web-based tool, Radiation Risk Assessment Tool (RadRAT; National Institutes of Health), and showed a reasonable agreement within the estimated confidential interval. Compared with RadRAT, SUMRAY can be used for a wide range of applications, as it allows the risk projection with arbitrarily specified risk models and/or population reference data. Conclusion: The reliabilities of SUMRAY with the present risk-model parameters and their variance-covariance matrices were verified by comparing them with those of the other codes. The SUMRAY code is distributed to the public as an open-source code under the Massachusetts Institute of Technology license.