• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.2
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• pp.219-224
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• 2016

Objectives: Lung cancer occurred with worker working in an urban bus garage. A survey was conducted to investigate whether lung cancer had causal relationship with work. Exposure to asbestos and diesel engine exhaust were suspected. Methods: Airborne asbestos was sampled on membrane filter and analyzed using phase-contrast microscopy. Airborne diesel exhaust was sampled using quartz filter and analyzed with thermal-optical analyzer. Polynuclear aromatic hydrocarbons was sampled using PTFE filter and XAD-2 tube and analyzed with gas chromatography-mass selective detector. Results: Airborne asbestos concentration was under 0.01 fiber/cc. Worker who warmed up an engine of urban bus for 2 hours was exposed to elemental carbon concentration, $15.5{\mu}g/m^3$. Only naphtalene among polynuclear aromatic hydrocarbons was detected. Conclusions: It was difficult to conclude about worker exposure to asbestos because working hour related asbestos was too short. In reviewing papers, the exposure to asbestos over 0.01 fiber/cc during exchange brake lining was found. It was identified that worker's occupational exposure to diesel exhaust based on elemental carbon was higher than the other occupational exposure to diesel exhaust.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.511-514
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• 2002

In may automated systems such as manufacturing systems and process plants, an industrial network or fieldbus is a very important component for the exchange of various and sometimes crucial information. Some of the information has a tendency to rapidly lose its value as time elapses after its creation. Such information or data is called real-time data that includes sensor values and control commands. In order to deliver these data in time, the fieldbus network should be tailored to have short delay with respect to the individual time limit of various data. Fine-tuning the network for a given traffic requires the knowledge on the relationship between the protocol parameters such as timer values and the performance measure such as network delay. This paper presents a mathematical performance model to calculate communication delays of the Profibus FMS network when the timer value TTR and the traffic characteristics are given. The results of this model is compared to those from experiments to assess the model's validity.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.5
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• pp.39-48
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• 2006

The objective of this research was to find an indirect method to estimate land surface temperature (LST) efficiently, using Landsat images. Agricultural fields including paddy fields have long been known to have multi-functions beneficial to the environment and ecology of the urban surrounding areas. Among these functions, the ambient temperature cooling (ATC) effect is widely acknowledged. However, quantitative and regional assessment of such effect has not been performed. Thermal remote sensing has been used over urban areas to assess the ATC effect, Thermal Island Effect(TIE), and as input for models of urban surface atmosphere exchange. Here, we review the use of thermal remote sensing in the study of paddy fields and urban climates, focusing primarily on the ATC effect. Landsat satellite images were used to determine the surface temperatures of different land cover types of a $44km^{2}$ study area in Cheongiu, Korea. The results show that the ATC is a function of paddy area percentage in Landsat pixels. Landsat pixels with higher paddy area percentage have much more cooling effect. The use of satellite data may contribute to a globally consistent method for analysis of ATC effect.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.8
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• pp.1019-1023
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• 2018

In this paper sensitivity analysis of temperature on special day electricity demand of land and Jeju Island is performed. The basic electricity demand per 3 hours is defined as electricity demand that reflects the GDP effect without the temperature influence. The temperature sensitivity per 3 hours is calculated through the relationship between special day electricity demand normalized to basic electricity demand and temperature. In the future, forecast error will be improved if the temperature sensitivity per 3 hours is applied to the special day load forecasting.

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.489-498
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• 2013

A new Bacillus strain degrading starch, named Bacillus sp. UEB-S, was isolated from a southern Tunisian area. Amylase production using solid-state fermentation on millet, an inexpensive and available agro-resource, was investigated. Response surface methodology was applied to establish the relationship between enzyme production and four variables: inoculum size, moisture-to-millet ratio, temperature, and fermentation duration. The maximum enzyme activity recovered was 680 U/g of dry substrate when using $1.38{\times}10^9$ CFU/g as inoculation level, 5.6:1 (ml/g) as moisture ratio (86%), for 4 days of cultivation at $37^{\circ}C$, which was in perfect agreement with the predicted model value. Amylase was purified by Q-Sepharose anion-exchange and Sephacryl S-200 gel filtration chromatography with a 14-fold increase in specific activity. Its molecular mass was estimated at 130 kDa. The enzyme showed maximal activity at pH 5 and $70^{\circ}C$, and efficiently hydrolyzed starch to yield glucose and maltose as end products. The enzyme proved its efficiency for digesting raw cereal below gelatinization temperature and, hence, its potentiality to be used in industrial processes.

• The Journal of Industrial Distribution & Business
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• v.6 no.4
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• pp.23-26
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• 2015

Purpose - To mislead shareholders about a firm's actual economic performance, managers frequently manage dividends. Earnings management also affects performance reviews. Managers attempt to manage reported earnings caused by current economic events to accurately reflect their current performance. Research design, data, and methodology - The sample consisted of 312 company-years from companies in the pharmaceutical distribution industry listed on the Tehran Stock Exchange. A study period from 2004 to 2014 was selected. In this study, a model for measuring the performance of the net profits to total assets of a division of Jones was used to measure earnings management. Results - This study found a negative correlation between corporate performance and earnings management. Conclusions - The results for the earnings management company indicated a significant inverse relationship. Therefore, the company's performance weakened as its earnings management activity increased. In other words, the results showed that the company's performance-based accruals earnings management, the actual management of profits, and the general level of earnings management had significant inverse relationships. Thus, as the company's profits declined, earnings management activity increased.

• The Journal of Industrial Distribution & Business
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• v.6 no.2
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• pp.5-11
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• 2015

Purpose - This research investigates the effect of disclosure quality with two main components, reliability and timeliness, on economic value added in Iran. Research design, data, and methodology - The sampling includes 170 Tehran Stock Exchange listed companies from 2008-12. Multiple regression analysis was applied to test the hypotheses and estimates of the coefficients. Firm size and return on assets were the control variables. Results - The results show that timeliness of information has a positive impact on economic value added. We did not find any significant relationship between disclosure quality and reliability of information and economic value added. The regressed model shows that there is no significant association between firm size and economic value added. The results also show that there is a positive association between return on assets and economic value added. Conclusions - Theoretically, timely information is effective in decision-making. This study shows that timeliness of information has positive effect on the creation of economic value added. However, disclosure quality, reliability, and firm size do not effect on economic value added. Companies with greater return on assets produce greater economic value added.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.2
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• pp.99-106
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• 2020

CEOs Overconfidence can bring potentially risky early decisions to businesses, along with large enterprise free cash flow that can bring different investment decisions with CEOs Overconfidence. Especially in the context of Vietnamese enterprises, CEOs are often influenced by behavioral psychology about overconfidence in investment decisions (due to individual cultural characteristics as well as operating financial markets also depend on many factors outside the market). Therefore, the authors study the impact of overconfidence and cash flow on investment in Vietnamese to find the internal relationship between these three factors in the financial environment in Vietnam. With 480 companies listed on the Vietnam Stock Exchange from 2014 to 2018 (companies have continuous reports), the regression analysis results with panel data (FEM, GLS models, correction of robust and GMM dealing with endogenous problems) have shown Overconfidence has a positive impact on investment. At the same time, the results also indicated that enterprises with overconfident CEOs and large cash flows tend to invest less than enterprises with low cash flow. The results of this study have shown the behavioral behavior of CEOs in Vietnamese enterprises that exist under both prospect theory and effective market theory.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.2
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• pp.21-31
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• 2020

Environmental pollution and climate change in Vietnam are now becoming a major concern. This situation is increasing the pressure on the companies to improve their social responsibility in production and business activities and disclose the environmental information to meet the requirements of stakeholders. This study investigates the internal and external factors of the company that affects the environmental information disclosure of listed companies on the Vietnam stock market as business sector, firm size, corporate manager perceptions, profitability, financial leverage, community pressure, pressures from stakeholders, government pressure influencing environmental information disclosure. Analytical data collected through the survey of 120 listed companies on the Ho Chi Minh City Stock Exchange (HOSE). By testing Cronbach's Alpha, exploratory factor analysis (EFA) and logistic regression analysis, the results of the study show that the level of environmental information disclosure of listed companies on the stock market in Vietnam depends heavily on government regulations, followed by the pressure from stakeholders, community pressure, views of business managers, companies size, business sector, and particularly profitability and financial leverage factors that have a negative relationship with environmental information disclosure.

• The Journal of Industrial Distribution & Business
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• v.8 no.1
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• pp.33-39
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• 2017

Purpose - The main purpose of the current study is to examine the impact of accounting information quality and information asymmetry on the underinvestment phenomenon among the listed companies on the Tehran Stock Exchange (TSE). Research design, data, and methodology - The population includes 94 firms selected through systematic sampling. The data is collected from the audited financial statements of the firms provided by TSE's website from 2010 to 2015. Accounting information quality and information asymmetry is considered as independent variables, and their impact is examined on the dependent variable (underinvestment). Results - The statistical results, based on data collected from 94 listed companies on the TSE during 2010-2015, revealed positive impact of accounting information quality and positive impact of information asymmetry on underinvestment. There was a significant relationship between accrual quality (AQ) and underinvestment, and spread and underinvestment. The results also showed that information asymmetry is the main factor in the creation underinvestment. Conclusions - Findings of this article can assist accounting researchers and theoreticians in comparing Real world facts with hypotheses developed with respect to accounting information quality, information asymmetry and underinvestment. However, the results of fuzzy regression analysis indicate significant relationships between the independent variable except underinvestment.