• Journal of Biomedical Engineering Research
• /
• v.28 no.4
• /
• pp.449-454
• /
• 2007

An electrohydraulic (EH) pump-driven closed-loop blood pressure regulatory system was developed based on flow-mediated vascular occlusion using the vascular occlusive cuff technique. It is very useful for investigating blood pressure-dependant physiological variability, in particular, that could identify the principal mediators of renal autoregulation, such as tubuloglomerular feedback (TGF) and myogenic (MYO), during blood pressure regulation. To address this issue, renal perfusion pressure (RPP) should be well regulated under various experimental conditions. In this paper, we designed a new EH pump-driven RPP regulatory system capable of implementing precise and rapid RPP regulation. A closed-loop servo-controlwas developed with an optimal proportional plus integral (PI) compensation using the dynamic feedback RPP signal from animals. An in vivo performance was evaluated in terms of flow-mediated RPP occlusion, maintenance, and release responses. Step change to 80 mmHg reference from normal RPP revealed steady state error of ${\pm}3%$ during the RPP regulatory period after PI action. We obtained rapid RPP release time of approximately 300 ms. It is concluded that the proposed EH RPP regulatory system could be utilized in in vivo performance to study various pressure-flow relationships in diverse fields of physiology, and in particular, in renal autoregulation mechanisms.

• Journal of Distribution Science
• /
• v.20 no.4
• /
• pp.65-75
• /
• 2022

Purpose: Environmental pollution problems have become more and more serious, how to effectively protect the environment has become a hot spot of concern to all sectors of society. The way to solve this problem is environmentally friendly management. However, theoretical perspectives and research frameworks of existing research on environmentally friendly management are still unclear. This study aims to examine how the CEO's beliefs for SMEs of Chinese distribution industry affect the environmentally friendly management based on institutional theory. Research design, data, and methodology: This paper collected data from 215 SMEs in China distribution industry and conducted a series of data analysis and hypothesis testing based on an institutional theory perspective using Amos and SPSS to verify the effects of regulatory pressure, normative pressure, and imitation pressure on firms' environmentally friendly management. Results: Through the analysis, this paper tests that normative pressure and imitative pressure have a positive effect on CEO's beliefs. However, regulatory pressure did not have a significant effect on beliefs of CEO. Meanwhile, the degree of CEO's beliefs has a positive effect on environmentally friendly management in Chinese distribution SMEs. Conclusions: Theoretical contributions, practical implications, and future research directions are discussed.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.7 no.3
• /
• pp.15-22
• /
• 2011

The chemistry factor and RTPTS margin for domestic reactor pressure vessel materials were analyzed by using the surveillance data which have been obtained from 8 nuclear power plants in Korea. The surveillance data have been used to assess the integrity of the pressure vessel under the pressurized thermal shock (PTS) event. The chemistry factor, which is determined by the Cu and Ni contents of vessel materials, is considered a proper tool to assess the $RT_{PTS}$. The chemistry factors, which were obtained from the surveillance data of domestic reactor pressure vessels, were investigated and compared with those of Regulatory Guide 1.99 in this study. Regressions for ${\Delta}RT_{NDT}$ were performed to expect the chemistry factor as a function of Cu and Ni, and to estimate $RT_{PTS}$ margin. The margin analysis was performed by comparing the regression graphs and standard deviations with those of Regulatory Guide 1.99. The standard deviations calculated by using the domestic surveillance data for base metal and welds are almost same as the standard deviations which are suggested on Regulatory Guide 1.99, Rev.2.

• Nuclear Engineering and Technology
• /
• v.49 no.5
• /
• pp.1109-1112
• /
• 2017

The precise prediction of radiation embrittlement of aged reactor pressure vessels (RPVs) is a prerequisite for the long-term operation of nuclear power plants beyond their original design life. The expiration of the operation licenses for Korean reactors the RPVs of which are made from SA533B-1 plates and welds is imminent. Korean regulatory rules have adopted the US Nuclear Regulatory Commission's transition temperature shift (TTS) models to the prediction of the embrittlement of Korean reactor pressure vessels. The applicability of the TTS model to predict the embrittlement of Korean RPVs made of SA533B-1 plates and welds was investigated in this study. It was concluded that the TTS model of 10 CFR 50.61a matched the trends of the radiation embrittlement in the SA533B-1 plates and welds better than did that of Regulatory Guide (RG) 1.99 Rev. 2. This is attributed to the fact that the prediction performance of 10 CFR 50.61a was enhanced by considering the difference in radiation embrittlement sensitivity among the different types of RPV materials.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.7 no.4
• /
• pp.57-62
• /
• 2011

As NPPs' operating times increase, the integrity of nuclear components is continually degraded due to aging effects of systems, structures and components. In addition, for the case of continued operation beyond design life, additional aging effects occurred during the extended operating period lead to more degradation of the integrity of nuclear components. Therefore, it is very important to mange and evaluate the aging to secure the safety of NPPs. Wolsong unit 1 is approaching to its design life of 30 years in 2012. The license renewal documents for continued operation of Wolsong unit 1 Is under reviewing now. In this paper, regulatory technologies for continued operation of Wolsong unit 1 developed by KINS will be introduced. That technologies include the safety review guidelines, regulatory guides for aging management program and regulatory program for audit calculation.

• Nuclear Engineering and Technology
• /
• v.42 no.6
• /
• pp.690-703
• /
• 2010

Sampling based uncertainty analysis was carried out to quantify uncertainty in predictions of best estimate code RELAP5/MOD3.2 for a thermal hydraulic test (10% hot leg break LOCA) performed in the Large Scale Test Facility (LSTF) as a part of an IAEA coordinated research project. The nodalisation of the test facility was qualified for both steady state and transient level by systematically applying the procedures led by uncertainty methodology based on accuracy extrapolation (UMAE); uncertainty analysis was carried out using the Latin hypercube sampling (LHS) method to evaluate uncertainty for ten input parameters. Sixteen output parameters were selected for uncertainty evaluation and uncertainty band between $5^{th}$ and $95^{th}$ percentile of the output parameters were evaluated. It was observed that the uncertainty band for the primary pressure during two phase blowdown is larger than that of the remaining period. Similarly, a larger uncertainty band is observed relating to accumulator injection flow during reflood phase. Importance analysis was also carried out and standard rank regression coefficients were computed to quantify the effect of each individual input parameter on output parameters. It was observed that the break discharge coefficient is the most important uncertain parameter relating to the prediction of all the primary side parameters and that the steam generator (SG) relief pressure setting is the most important parameter in predicting the SG secondary pressure.

• Plant Journal
• /
• v.8 no.1
• /
• pp.60-72
• /
• 2012

In this study to reduce the review time of the pressure vessel regulations pressure vessel legislation review program has been developed. During the course of this research program to develop the domestic construction in a real project, saving 47% of the time was found.

• The Korean Journal of Physiology
• /
• v.3 no.2
• /
• pp.25-31
• /
• 1969

Effects of graded increase of positive lung inflation upon heart rates and arterial blood pressure were observed in the anesthetized dogs to analyze the mechanical and neural regulatory factor in response to the positive inflation of the lung. The results obtained were summarized as followings: 1) When the low grade of positive lung inflation was employed under the mild to moderate anesthesia, central venous pressure was linearly increased while heart rate was decreased. After bilateral vagotomy, central venous pressure was obviously increased while heart rate was constant. 2) When the high degree of positive lung inflation was employed, changes of central venous pressure and heart rate were not significant. 3) The low grade of intrapulmonary pressure increase caused reflex tachycardia in phase 2 and overshooting in phase 4 in response to the systemic arterial blood pressure change. 4) On the other hand, the high degree of intrapulmonary pressure increase caused paradoxical bradycardia in phase 2 and lack of overshooting in phase 4 in response to the systemic arterial blood pressure change. 5) It may be noted that the experimental model employed in the present study is a useful tool to evaluate and analyze the neural and mechanical regulatory factor in response to the graded increase of the positive lung inflation.

• Nuclear Engineering and Technology
• /
• v.45 no.3
• /
• pp.277-294
• /
• 2013

In the early 1980s, attention focused on the possibility that pressurized thermal shock (PTS) events could challenge the integrity of a nuclear reactor pressure vessel (RPV) because operational experience suggested that overcooling events, while not common, did occur, and because the results of in-reactor materials surveillance programs showed that RPV steels and welds, particularly those having high copper content, experience a loss of toughness with time due to neutron irradiation embrittlement. These recognitions motivated analysis of PTS and the development of toughness limits for safe operation. It is now widely recognized that state of knowledge and data limitations from this time necessitated conservative treatment of several key parameters and models used in the probabilistic calculations that provided the technical of the PTS Rule, 10 CFR 50.61. To remove the unnecessary burden imposed by these conservatisms, and to improve the NRC's efficiency in processing exemption and license exemption requests, the NRC undertook the PTS re-evaluation project. This paper provides a synopsis of the results of that project, and the resulting Alternate PTS rule, 10 CFR 50.61a.

• Journal of Soil and Groundwater Environment
• /
• v.17 no.6
• /
• pp.9-22
• /
• 2012

Though geologic storage of $CO_2$ (GS) is considered as an attractive technological option to enormously reduce greenhouse gases emission into the atmosphere, many concerns on potential environmental and health risks associated with $CO_2$ leakage have been raised. In particular, groundwater contamination due to the brine displacement by a pressure build-up and the acidification by leaked $CO_2$ is paid a special attention. Therefore, integrated regulatory frameworks have been established by law in many countries to secure the permanent containment of injected $CO_2$. Regulatory frameworks deal with entire processes of GS, including site selection, monitoring and post-closure environmental management. This review paper provides a summary of regulatory frameworks in USA (U.S. EPA Geologic Sequestration Rule) and EU (Geologic $CO_2$ Sequestration Directive). The regulatory framework to properly address environmental issues should be established for the deployment of CCS projects in Korea.