• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 한국에너지공학회 2000년도 추계 학술발표회 논문집
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• pp.115-120
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• 2000

The analysis of flux distribution under stead-state in large power reactors with assymetry reactivity insertions requires the use of three-dimensional diffusion calculations. For the purpose, consistently formulated modern nodal methods based on higher order interface techniques have become popular tools for flux distributions in large commercial nuclear reactors. Among the earlier developments, the nodal Green's function method obtains its nodal interface equation from the transverse-integrated integral diffusion equation using a finite-medium Green's function. In this method, the outgoing current from a node surface is formulated as a response of the incoming currents and the spatially integrated neutron source within the same node. The well-known nodal expansion method is also based on an interface partial current formulation. Nodal methods high-level interface variables, i.e., interface net current and flux, may be more computationally efficient than the nodal Green's function method because they have one fewer unknown per interface. The Analytic Nodal Method(ANM), which can be classified as an interface net current technique and, was faster in solving some standard benchmark problems than the other two methods.(omitted)

• Archives of Pharmacal Research
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• 제23권4호
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• pp.267-282
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• 2000

Cytochrome P45O (CYP) 2E1 catalyzes the metabolism of a wide variety of therapeutic agents, procarcinogens, and low molecular weight solvents. CYP2E1-catalyzed metabolism may cause toxicity or DNA damage through the production of toxic metabolites, oxygen radicals, and lipid peroxidation. CYP2E1 also plays a role in the metabolism of endogenous compounds including fatty acids and ketone bodies. The regulation of CYP2E1 expression is complex, and involves transcriptional, post-transcriptional, translational, and post-translational mechanisms. CYP2E1 is transcriptionally activated in the first few hours after birth. Xenobiotic inducers elevate CYP2E1 protein levels through both increased translational efficiency and stabilization of the protein from degradation, which appears to occur primarily through ubiquitination and proteasomal degradation. CYP2E1 mRNA and protein levels are altered in response to pathophysiologic conditions by hormones including insulin, glucagon, growth hormone, and leptin, and growth factors including epidermal growth factor and hepatocyte growth factor, providing evidence that CYP2E1 expression is under tight homeostatic control.

• Preventive Nutrition and Food Science
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• 제5권2호
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• pp.109-113
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• 2000

In this study, a potential mechanism through which the hesperidin might work on the effect was examined in vivo. Male rats were fed a high cholesterol synthetic diet (1%, wt/wt) with hesperidin (0.1%, wt/wt) for 42 days. Activity of hepatic HMG-CoA reductase was significantly lowered by the hesperidin supplement compared to the control. Hesperidin did not significantly alter plasma or hepatic lipids, but tended to lower those lipid levels. Hesperidin also subsequently reduced the fecal neutral sterols compared to the control(253.3mg/d vs.521.9 mg/d). The inhibition of HMG-CoA reductase resulting from the hesperidin supplementation could count for the reduction in fecal neutral sterols that appears to compensate for the decreased cholesterol biosynthesis. The dose of hesperidin in a high choles-terol diet should apparently be more than 0.1% to exhibit the hypocholesterolemic response in these rats. It remains to be determined whether the observed alterations in cholesterol metabolism are specific to the rat or also could be applied to the humans.

• Structural Engineering and Mechanics
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• 제86권1호
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• pp.29-48
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• 2023

Pounding happens when contiguous structures with differing heights vibrate out of line caused by a seismic activity. The situation is aggravated due to the insufficient separation gap between the structures which can lead to the crashing of the buildings or total collapse of an edifice. Countries around the world have compiled building standards to address the pounding issue. One of the strategies recommended is the introduction of the separation gap between structures. AS1170.4-2007 is an Australian standard that requires 1% of the building height as a minimum separation gap between buildings to preclude pounding. This article presents experimental and numerical tests to determine the adequacy of this specification to prevent the occurrence of seismic pounding between steel frame structures under near-field and far-field earthquakes. The results indicated that the recommended minimum separation gap based on the Australian Standard is inaccurate if low-rise structure in a coupled case is utilised under both near and far field earthquakes. The standard is adequate if a tall building is involved but only when a far-field earthquake happens. The research likewise presents results derived by using the ABS and SRSS methods.

• The Southeast Asian review
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• 제22권1호
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• pp.207-245
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• 2012

With rapid industrialization and urbanization, numerous cities are faced with urban slum phenomenon combined with housing shortage fueled by population explosion. In Kuala Lumpur, the capital city of Malaysia, the government hereby embarked on supply of public housing to resolve such pending issue. This study aims to understand the periodic changes of public housing as a common basis for basic housing policies with analysis specific features of site plan, block layout, and unit plans. For this purposes, the filed survey during January, 2011 were proceeded. We hereby visited and surveyed a total of 40 apartment complexes for the 1970s~the 2000s (10 complexes respectively on a decade basis). Consequently, Malaysian public apartments prove to offer a very uniform pattern based upon standard plans. Their early plans aren't fairly distincted from those of other countries, but their layouts of plan become differentiated compared with other nations as they actively apply a ventilator called 'air well' in response to tropical climate amid the change of times. This study is expected to broaden our understanding of Malaysia's unique housing culture and lifestyle.

• Journal of Korean Society of Rural Planning
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• 제29권4호
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• pp.183-189
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• 2023

As South Korea faces a general decline in population, similar to other regions, its rural areas are also experiencing a downward trend. This study examines how the scale and shifts in population within rural towns(eup·myeon) are affecting the number of essential services such as hospitals, laundry shops, and beauty salons. Our analysis encompassed the populations of 1,403 towns, excluding nine areas due to lack of data as of 2020. Since the availability of basic services can vary with population size, we normalized the figures to reflect the number of services per 10,000 people, allowing for a comparative analysis across different population sizes. Generally, areas with more people showed an increase in the number of services per capita. Our review of changes from 2000 to 2020 revealed patterns in how service numbers adjust with population variations. Future research should delve into more detailed trends of these facilities and forecast the rural population's future to ensure that residents in areas where service sustainability may be challenging will have full access to necessary services.

• Structural Engineering and Mechanics
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• 제90권1호
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• pp.51-70
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• 2024

Poorly designed reinforced concrete (RC) columns of actual moment-resisting frame (MRF) buildings can undergo Axial Compression Ratios (ACR) so high as their demand exceeds their capacity, even for serviceability gravity load combinations, this lack commonly leads to insufficient seismic strength. Nonetheless, many seismic design codes do not specify limits for ACR. The main contribution of this research is to investigate the need to limit the ACR in seismic design. For this purpose, three prototype 6 and 11-story RC MRF buildings are analyzed in this paper, these buildings have columns undergoing excessive ACR, according to the limits prescribed by standards. To better that situation, three types of alterations are performed: retrofitting the abovementioned overloaded columns by steel jacketing, increasing the concrete strength, and reducing the number of stories. Several finite element analyses are conducted using the well-known software SAP2000 and the results are used for further calculations. Code-type and pushover analyses are performed on the original and retrofitted buildings, the suitability of the other modified buildings is checked by code-type analyses only. The obtained results suggest that ACR is a rather reliable indicator of the final building strength, hence, apparently, limiting the ACR in the standards (for early stages of design) might avoid unnecessary verifications.

• Steel and Composite Structures
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• 제52권6호
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• pp.673-693
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• 2024

An advanced numerical method is proposed in this paper for the second-order inelastic dynamic analysis of cable-stayed bridges using rectangular concrete-filled steel tubular (CFST) columns under earthquake loadings for the first time. The proposed method can exactly predict the nonlinear response of the bridges by using only one element per member in simulating the structural model. This comes from considering both the geometric and material nonlinearities in a fiber beam-column element and a catenary cable element. In the fiber beam-column element, the geometric nonlinearities are captured by applying the stability functions, whereas the material nonlinearities are evaluated by tracing the uniaxial cyclic stress-strain curves of each fiber on the cross-sections, which are located at the integration points along the member length. A computer program was developed based on Newmark's average acceleration algorithm to solve the nonlinear equations of motion. The accuracy and computational efficiency of the proposed program were verified by comparing the predicted results with the experimental results, and the results obtained from the commercial software SAP2000 and ABAQUS. The proposed program is promising as a useful tool for practical designs for the nonlinear inelastic dynamic analysis of cable-stayed bridges.

• Women's Health Nursing
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• 제6권4호
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• pp.549-565
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• 2000

Comprehensive review of the literature was conducted to determine 1) selected risk factors and its impact that affect pregnancy outcome such as smoking, alcohol consumption, and substance abuse 2) these factors can facilitate future strategies for health promotion and prevention for both pregnant women and fetus. Review of literature were extracted from searching MEDLINE(1966 - Oct. 2000). CINAHL (1982 - Oct. 2000) and the domestic literature. The following factors were identified: 1. The effects of risk behaviors on pregnancy. ${\cdot}$Maternal smoking was associated with the occurrence of premature or LBW delivery, fetal growth retardation, extremities defects, heart defects and sudden infant death syndrome. ${\cdot}$Maternal alcohol consumption was associated with spontaneous abortion, premature or LBW delivery, morphologic/neurologic problems, especially fetal alcohol syndrome. ${\cdot}$Heroin was associated with withdrawal after birth in which were born to heroine addicts for gestational age and lung maturation in animal studies. ${\cdot}$Cocaine was associated with spontaneous abortion, abruptio placenta and a poor response to environmental stimuli. ${\cdot}$So far, the effects of caffeine on pregnancy was controversial, but severe caffeine consumption was associated with premature or LBW delivery, spontaneous abortion, still birth and dystocia. 2. Intervention methods and its effects identified were as follows ${\cdot}$Conducted intervention for smoking, alcohol and drug consumption were single or combined. ${\cdot}$Intervention methods were counseling, phone contact, mailing, use of educational videotape, booklet, support person and alternatives such as nicotine patch. ${\cdot}$The interventions increased the rates of smoking cessation during pregnancy and awareness of the risk of drug consumption, and decreased amount of alcohol consumption. ${\cdot}$The intervention outcome found positive effect on birth weight and length. 3. Our recommendations were as follows ${\cdot}$The personal and social cognition should be enhanced through education and the mass media. ${\cdot}$It's necessary to educate and give information of preconceptional care, planned pregnancy and early prenatal care for optimal pregnancy outcome. ${\cdot}$It's necessary to develop comprehensive assessment tool which is reliable and valid on smoking, alcohol consumption and substance abuse to identify supportive or interventional program.

• Journal of the Institute of Electronics Engineers of Korea SD
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• 제37권8호
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• pp.28-34
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• 2000

Pyroelectric properties of the $Pb(Zr_{0.9}Ti_{0.1})O_3$ ceramics having the rhombohedral structure have been studied by using the dynamic measurement method. The pyroelectric responses of the $Pb(Zr_{0.9}Ti_{0.1})O_3$ ceramics are characterized in both low and high medulation frequency regions and their frequency depences are observed. In the low frequency region (2~200Hz), the change of polarization increases and shows the maximum since the reorientation rate of domains is higher than the modulation frequency. Inthe high frequency region (200~2000Hz), the pyroelectrci response decreases as the frequency increases, because the reorientation of domains is suppressed and so the change of polarization decreases. Pyroelectric coefficient, figure of merit, noise equivalent power and detectivity of the $Pb(Zr_{0.9}Ti_{0.1})O_3$ ceramics are measured as $1.6{\times}10^{-8}C/cm^2{\cdot},\;1.6{\times}10^{-11}C{\cdot}cm/J,\;2.4{\times}10^{-7}W/Hz^{1/2}\;and\;4.17{\times}10^6cm{\cdot}Hz^{1/2}/W$, respectively.