• The Journal of Asian Finance, Economics and Business
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• 제7권2호
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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.

• Wind and Structures
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• 제36권6호
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• pp.405-421
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• 2023

Strong wind is the main factors of wind-damage of high-rise buildings, which often creates largely economical losses and casualties. Wind pressure plays a critical role in wind effects on buildings. To obtain the high-resolution wind pressure field, it often requires massive pressure taps. In this study, two traditional methods, including bilinear and bicubic interpolation, and two deep learning techniques including Residual Networks (ResNet) and Generative Adversarial Networks (GANs), are employed to reconstruct wind pressure filed from limited pressure taps on the surface of an ideal building from TPU database. It was found that the GANs model exhibits the best performance in reconstructing the wind pressure field. Meanwhile, it was confirmed that k-means clustering based retained pressure taps as model input can significantly improve the reconstruction ability of GANs model. Finally, the generalization ability of k-means clustering based GANs model in reconstructing wind pressure field is verified by an actual engineering structure. Importantly, the k-means clustering based GANs model can achieve satisfactory reconstruction in wind pressure field under the inputs processing by k-means clustering, even the 20% of pressure taps. Therefore, it is expected to save a huge number of pressure taps under the field reconstruction and achieve timely and accurately reconstruction of wind pressure field under k-means clustering based GANs model.

• 경영과학
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• 제32권3호
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• pp.71-89
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• 2015

This research empirically investigated the influence factors on the activation of environmental innovations (EI) in Korean manufacturing firms. In this study, external factors (compulsory demand, government regulation, normative pressure and imitative pressure) and internal factors (environmental resources, top management support, integration of environmental tasks, capabilities of environmental personnel, and environmental strategy/environmental management systems) were totally considered. The results of a multiple regression analysis showed that influence factors such as top management support, environmental resources and integration of environmental tasks have a significant and positive impact on levels of EI. However, the effects of external factors were not statistically significant. We also examined whether capabilities of environmental personnel as well as environmental resources, which are directly related with degrees of EI, have a moderating impact on relationships between other internal factors and levels of EI. With a subgroup analysis, the moderating role of abilities of environmental personnel were empirically confirmed. Through a multiple regression analysis, the direct effects of external factors on the adoption or construction of internal factors were demonstrated. The effects of government regulation, normative pressure and imitative pressure on internal factors were significant and positive. It was also found that external factors have indirect effects on EI through internal factors. Finally, the results of multiple regression analyses indicated that EI positively influences the achievement of environmental competitive benefits, and environmental competitive advantages can improve the organizational performance of a firm.

• 환경위생공학
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• 제22권1호
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• pp.67-74
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• 2007

The purpose of this study is to provide the necessarily basic data of the ideal growth of the students by investigating the effect of the student's stress due to the parent's achievement pressure. The sample of this study are In students consisting of 51 boys and 49 girls in the 3rd grade classes of "J" middle school located in Siheung city, Kyungki-do. The observed materials are used to investigate the parent's achievement pressure and the level of stress. Based on the observed data, the frequency, correlation, and t-test have been gained. The results are summarized as follows : 1. The perception of the parent's achievement pressure is shown more by the boy's achievement pressure($44.2{\pm}9.9$) than the girl's achievement pressure($39.939{\pm}11.089$), among the high level students. 2. The perception of the parent's achievement pressure is shown more the high($43.0{\pm}10.7$) and middle($42.9{\pm}11.8$) level students than the low($39.7{\pm}8.00$) level students. 3. The stress of male students was high in the Solving Problem stress factor with by the mean of $15.1{\pm}3.7$, and the stress of female students was high in the Self-Control stress factor with the mean of $13.3{\pm}3.9$. 4. The stress of high, middle, low level student was high in the Solution of Matter stress factor with the mean of $14.2{\pm}3.9$. 5. The results were the main cause of the stress than the parent's achievement pressure.

• 한국환경과학회지
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• 제19권4호
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• pp.437-446
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• 2010

The pressure drop through pulse air jet-type bag filter is one of the most important factors on the operating cost of bagfilter houses. In this study, the pilot-scale pulse air jet-type bag filter with about 6 m2 filtration area was designed and tested for investigating the effects of the four operating conditions on the total pressure drop, using the coke dust collected from a steel mill factory. When the face velocity is higher than 2 m/min, it is not applicable to on-spot due to the increase of power expenses resulting from a high-pressure drop, and thus, 1.5 m/min is considered to be reasonable. The regression analysis results show that the degree of effects of independent parameters is a order of face velocity > concentration > time > pressure. The results of SPSS answer tree analysis also reveal that the operation time affects the pressure drop greatly in case of 1 m/min of face velocity, while the inlet concentration affects the pressure drop in case of face velocity more than 1.5 m/min.

• 한국산업보건학회지
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• 제24권2호
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• pp.137-145
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• 2014

Objectives: The study examines the relation between urinary arsenic concentration and blood pressure, which is a risk factor of cardiovascular disease. Materials: In this study, the urinary arsenic concentration, history of diagnosed disease, and blood pressure of 782 local residents in Gwangyang, Yeosu, and Hadong regions from May 2007 to July 2007. Results: The urinary arsenic concentration of total participants was $9.06{\mu}g/g-ct$. The logistic regression analysis of medical diagnosed history and urinary arsenic concentration, showed statistically significance (p<0.05) of high urinary arsenic concentration in participants with diagnosed hypertension. In addition, diagnosed hypertension it was observed that the high blood pressure was related with the pulse pressure. Conclusions: The arsenic concentration level was low in this study, but the exposure to low levels of arsenic has an effect on hypertension. Also, hypertension is related to pulse pressure and mean arterial blood pressure as well as being risk factor of cardiovascular disease. Therefore, close supervision of low -level arsenic exposure is needed.

• Geomechanics and Engineering
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• 제15권3호
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• pp.823-831
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• 2018

The most important issue during shield TBM tunneling in soft ground formations is to appropriately control ground surface settlement. Among various operational conditions in shield TBM tunneling, the face pressure and backfill pressure should be the most important and immediate measure to restrain surface settlement during excavation. In this paper, a 3-D hydro-mechanical coupled FE model is developed to numerically simulate the entire process of shield TBM tunneling, which is verified by comparing with real field measurements of ground surface settlement. The effect of permeability and stiffness of ground formations on tunneling-induced surface settlement was discussed in the parametric study. An increase in the face pressure and backfill pressure does not always lead to a decrease in surface settlement, but there are the critical face pressure and backfill pressure. In addition, considering the relatively low permeability of ground formations, the surface settlement consists of two parts, i.e., immediate settlement and consolidation settlement, which shows a distinct settlement behavior to each other.

• Geomechanics and Engineering
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• 제18권2호
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• pp.205-213
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• 2019

A calculation model of reservoir pressure field distribution around multiple production wells in a heavy oil reservoir is established, which can overcome the unreasonable uniform-pressure value calculated by the traditional mathematical model in the multiwell mining areas. A calculating program is developed based on the deduced equations by using Visual Basic computer language. Based on the proposed mathematical model, the effects of drainage rate and formation permeability on the distribution of reservoir pressure are studied. Results show that the reservoir pressure drops most at the wellbore. The farther the distance away from the borehole, the sparser the isobaric lines distribute. Increasing drainage rate results in decreasing reservoir pressure and bottom-hole pressure, especially the latter. The permeability has a significant effect on bottom hole pressure. The study provides a reference basis for studying the dynamic pressure field distribution before thermal recovery technology in heavy oilfield and optimizing construction parameters.

• Journal of Preventive Medicine and Public Health
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• 제38권4호
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• pp.401-407
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• 2005

Objectives : We wanted to investigate the relationship between heavy metal, especially lead and mercury, to the blood pressure and cholesterol level in children. Methods : This study was undertaken in three primary schools and the study subjects were a total of 274 children. The lead in the blood and the urine mercury were analyzed by performing atomic absorption spectroscopy. Results : All of participants' blood lead levels and urine mercury concentrations were below the suggested level of concern according to the criteria of the CDC and ATSDR. We found no significant correlation between lead, mercury and the blood pressure. The blood lead level did not show any relationship with the blood pressure and cholesterol. However, the urine mercury levels were associated with the serum cholesterol. Conclusion : Our study suggests that mercury can induce an increase of cholesterol as a risk factor of myocardial infraction and coronary/cardiovascular disease.

• 한국환경과학회지
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• 제29권5호
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• pp.457-468
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• 2020

With continuous industrial development, the types, and amount of particulate matter (PM) have been increasing. Since 2018, environmental standards regarding PM have become more stringent. Pulse air jet bag filters are suitable for PM under the 20 ㎛ and, can function regardless of size, concentration and type. Filtration velocity and shape are important factors in the operation and design of the pulse air jet bag filters however, few established studies support this theory. In this research, numerical simulations were conducted based on experimental values and, several methods were employed for minimizing the pressure drop. In the pilot system, as the inlet duct velocity was faster than 19 m/sec, flow was not distributed equally and, re-entrainment occurred due to the hopper directional vortex. The multi-inlet system decelerated the hopper directional vortex by 25 ~ 30%, thereby decreasing total pressure drop by 6.6 ~ 14.7%. The guide vane system blocked the hopper directional vortex, which resulted optimal vane angle of 53°. The total pressure of the guide vane system increased by 0.5 ~ 3% at 1.5 m/min conditions. However, the filtration pressure drop decreased by 4.8 ~ 12.3% in all conditions, thereby reducing the operating cost of filter bags.