• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.246-246
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• 2023

Multi-purpose dams are operated accounting for both physical and socioeconomic factors. This study aims to evaluate the utility of a deep learning algorithm-based model for three multi-purpose dam operation (Seomjin River dam, Juam dam, and Juam Control dam) in Seomjin River. In this study, the Gated Recurrent Unit (GRU) algorithm is applied to predict hourly water level of the dam reservoirs over 2002-2021. The hyper-parameters are optimized by the Bayesian optimization algorithm to enhance the prediction skill of the GRU model. The GRU models are set by the following cases: single dam input - single dam output (S-S), multi-dam input - single dam output (M-S), and multi-dam input - multi-dam output (M-M). Results show that the S-S cases with the local dam information have the highest accuracy above 0.8 of NSE. Results from the M-S and M-M model cases confirm that upstream dam information can bring important information for downstream dam operation prediction. The S-S models are simulated with altered outflows (-40% to +40%) to generate the simulated water level of the dam reservoir as alternative dam operational scenarios. The alternative S-S model simulations show physically inconsistent results, indicating that our deep learning algorithm-based model is not explainable for multi-purpose dam operation patterns. To better understand this limitation, we further analyze the relationship between observed water level and outflow of each dam. Results show that complexity in outflow-water level relationship causes the limited predictability of the GRU algorithm-based model. This study highlights the importance of socioeconomic factors from hidden multi-purpose dam operation processes on not only physical processes-based modeling but also aritificial intelligence modeling.

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

• The Journal of the Korea Contents Association
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• v.19 no.5
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• pp.280-286
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• 2019

This study first examines whether the matching principle reduces information asymmetry and verifies the effect on earnings sustainability and information asymmetry. In the presence of information asymmetry between managers and information users, managers can reduce information asymmetry by increasing the quality of earnings. Information asymmetry is measured by the financial analysts' earnings forecast variance. When we look at the results of previous studies, verify whether information asymmetry decreases as the response to the revenue cost increases and whether negative relationship between profit persistence and information asymmetry appears when the response to the revenue cost is high. As a result, firms with high revenue cost response showed a decrease in information asymmetry. The persistence of the earningss from the high earnings-cost response shows that the analysts' earnings forecast dispersion decreases. This means that the better the response to the revenue cost, the better the quality of the earnings and the less the information risk about the uncertainty of the enterprise. This study is different from the previous studies in that it analyzed whether the persistence of the earnings that responded to the high revenue cost reduces the information asymmetry. The results of this study suggest that managers can reduce the information asymmetry by carrying out appropriate revenue - cost responses, which provides important implications for stakeholders who use accounting earnings information.

• East Asian Journal of Business Economics (EAJBE)
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• v.4 no.3
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• pp.25-30
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• 2016

Small and Medium enterprises (SMEs) make important contributions to economic and social development of the country. The aim of this study was to determine the extent of financial management practices employed by the SME's and their effect on growth. This study was conducted quantitatively through descriptive research design; the data was collected from sample size of 120 of some SMEs operate in Mogadishu. Used questionnaire as data collection tool, the data analysis was done by using the statistical package SPSS version16, the data analyzed and presented by calculation, determining frequency, percentages, mean and standard deviation. Therefore the researchers found result revealed that extent of financial management is low among small and medium enterprises and also, that the financial management is significantly influence on the on growth of small and medium enterprises in Mogadishu Somalia. Furthermore the findings revealed that the cash management, accounts receivable and inventory management are low among SME. Also that most of the selected SME don not make financial plan to their business, at the end that most of the selected SME don not have formal accounting information system to their business.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.3
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• pp.228-239
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• 2004

In this paper, an analytical model accounting for the quantum effects in MOSFETs has been developed to study the behaviour of $high-{\kappa}$ dielectrics and to calculate the threshold voltage of the device considering two dielectrics gate stack. The effect of variation in gate stack thickness and permittivity on surface potential, inversion layer charge density, threshold voltage, and $I_D-V_D$ characteristics have also been studied. This work aims at presenting a relation between the physical gate dielectric thickness, dielectric constant and substrate doping concentration to achieve targeted threshold voltage, together with minimizing the effect of gate tunneling current. The results so obtained are compared with the available simulated data and the other models available in the literature and show good agreement.

• The Journal of Industrial Distribution & Business
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• v.11 no.1
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• pp.19-28
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• 2020

Purpose: This research aims to empirically investigate the motivation of corporate voluntary disclosure by exploring the impact of historical loss on corporate social responsibility disclosure (CSRD). Research design, data, and methodology: This paper takes Chinese A-share listed firms that issued standalone social responsibility reports during the period of 2009-2017 as a sample. Drawing on extant literature, this paper defines historical loss firms as firms with net profit greater than or equal to 0 and undistributed profit less than 0. The tendency score matching method (PSM) is used to find matching samples for historical loss firms. Then OLS regression is conducted to investigate the relationship between historical loss and corporate social disclosure. Results: The results show that historical loss has a significant positive impact on the quality of corporate social responsibility disclosure. After changing the measurement of independent and dependent variables as well as adopting different matching methods to screen the control group, the results still hold. Further research indicates that the relationship between historical loss and CSRD is influenced by corporate financing constraints and industry competition. Conclusions: This research supports the resource motivation hypothesis of corporate social responsibility disclosure, and provides empirical evidence for regulators to strengthen supervision on corporate disclosure.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.356-362
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• 2017

This paper presents a robust position controller for a one degree-of-freedom (DOF) mechanical system using only position measurement. In order to alleviate the performance degradation owing to various uncertainties, a two-stage design method is studied by employing a proportional integral observer (PIO). In the first stage, a baseline backstepping controller is designed for a nominal system without accounting for uncertainties. The PIO is developed for estimating both the velocity information for the backstepping controller and an equivalent input disturbance for a feedforward compensation using the estimated uncertainty. It is shown that the estimation errors with the proposed PIO can be made arbitrarily small in a finite time. If the system suffers from undesirable actuator nonlinearities, however, it might be necessary to estimate the velocity and the disturbance with different rates of convergence. The proposed method combines the predesigned backstepping controller and dual PIOs to reduce mechanical vibrations as well as steady-state errors. The performance of the proposed method is tested through comparative computer simulations and experiments using a laboratory prototype.

• Asian Journal of Business Environment
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• v.9 no.1
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• pp.21-28
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• 2019

Purpose - The purpose of this paper is to investigate the relationship between corporate social responsibility disclosure (CSRD) and investment-cash flow sensitivity, which is a surrogate for financing constraints. Research design, data, and methodology - Taking China's A-share listed companies between 2009 and 2016 as a sample, this paper empirically tests the relationship between CSRD and investment-cash flow sensitivity by Panel VAR model. By introducing the orthogonal impulse response function, this paper distinguishes the fundamental factors and financial ones that affect corporate investment behavior. Results - Findings indicate that: (1) investment-cash flow sensitivity of firms with low level of CSRD is significantly lower than that of firms with high level of CSRD; (2) the orthogonal impulse response of corporate investment to cash flow in firms with high level of CSRD is significantly different from zero, but it is not significant in firms with low level of CSRD; (3) for firms with low level of CSRD, 0.7% of corporate investment volatility can be explained by the change in cash flow, which is lower than that of firms with high level of CSRD (1.1%). Conclusions - Corporations disclosing more and higher quality CSRD are often those faced with financing constraints. Voluntary disclosure can help them alleviate information asymmetry and financing constraints.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.3
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• pp.348-355
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• 2000

Loyalty is a bonus point that a customer earns in reward of purchasing goods of a shop or a manufacturer. The management of loyalty such as issuing, accounting, reimbursing is carried out by the loyalty system. Traditional loyalty systems were proprietary. As a result, the systems are not interoperable with each other. However, our loyalty system allows a group of merchants join together and use the same IC card to operate their own loyalty programs. Data and counters can be shared or totally isolated, using secret codes and keys. The loyalty pool system communicates with the loyalty service providers over the Internet and performs the management of loyalty in fully automated manner. This paper describes the functional architecture and internal behavior of the loyalty pool system along with the communication protocols.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.4
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• pp.79-94
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• 2013

In this paper, we examine factors of success in online P2P (peer-to-peer) lending auctions. This paper finds the following empirical results. First, loan applicants with a stable employment status are more likely to succeed in the auction than loan applicants with an unstable employment status. Second, loan applicants, who actively share personal information and interact with lenders through online message boards, are likely to succeed in the auction. Third, the purpose of a loan for debt repayment has a significant impact on the success of the auction. However, the purpose of a loan for essential living expenses such as housing, living, and medical expenses has an insignificant relationship with the success of the auction. Our results imply that the characteristics of loan applicants such as employment status and social interaction are the factors of success in online P2P lending auctions.