• Tribology and Lubricants
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• v.38 no.4
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• pp.152-161
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• 2022

Chemical mechanical planarization (CMP) is a technology that planarizes the surfaces of semiconductor devices using chemical reaction and mechanical material removal, and it is an essential process in manufacturing highly integrated semiconductors. In the CMP process, a conditioning process using a diamond conditioner is applied to remove by-products generated during processing and ensure the surface roughness of the CMP pad. In previous studies, prediction of pad wear by CMP conditioning has depended on numerical analysis studies based on mathematical simulation. In this study, using an artificial neural network, the ratio of conditioner coverage to the distance between centers in the conditioning system is input, and the average conditioning density, standard deviation, nonuniformity (NU), and conditioning density distribution are trained as targets. The result of training seems to predict the target data well, although the average conditioning density, standard deviation, and NU in the contact area of wafer and pad and all areas of the pad have some errors. In addition, in the case of NU, the prediction calculated from the training results of the average conditioning density and standard deviation can reduce the error of training compared with the results predicted through training. The results of training on the conditioning density profile generally follow the target data well, confirming that the shape of the conditioning density profile can be predicted.

• Korean Journal of Clinical Pharmacy
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• v.10 no.3
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• pp.101-106
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• 2000

Menopausal women experience urogenitory and vasomotor symptoms with increased risk of osteoporosis and cardiovascular diseases, which can be reduced by hormone replacement therapy. However unopposed estrogen therapy has been associated with an increased risk of endometrial hypeiplasia or cancer. The objectives of this study were to compare effects of continuous vs. sequential hormone replacement therapy (HRT) on lipid profile, bone mineral density and menopausal symptoms of postmenopausal women and to assess how they perceive the menopause and HRT culturally. In this retrospective study, women in menopause longer than 6 months, normal in the mam-mogram and Papanicolaou smear, cholesterol level lower than 190 mg/dL or triglyceride level lower 4han 500 mg/dL were treated with Srogen (conjugated equine estrogen 0.625 mg tablet) and Provera (medroxyprogesterone acetate 2.5 mg tablet) for continuous treatment(CT) or Cycloprogynova (Estradiol valerate 2 mg and Norgestrel 0.5 mg complex tablet) for sequential treatment(ST). They were evaluated for lipid profile, bone mineral density, menopausal symptoms, side effects and their perception of menopause and HRT. As results, total sixty-seven patients out of ninety-four enrollees were included in final analysis (33 in continuous therapy, 34 in sequential therapy). There were significant decrease in total cholesterol ($15.04\pm3.17$, p=0.0001), LDL ($19.72\pm3.27$, p=0.0001), and increase in HDL ($5.89\pm1.63$, p=0.0001). Bone minora) density increased significantly with HRT ($0.02\pm0.11$, p=0.0001). But, there were no significant differences in change of lipid profile between continuous and sequential therapy: Total cholesterol, $13.12\pm4.7\;vs.\;16.91\pm4.3;\;LDL\;20.53\pm4.1\;vs.\;18.93\pm5.12:HDL\;7.15\pm2.3\;vs.\;4.67\pm2.2,\;p>0.05$. Incidences of flush reduced from $75\%\;(CT)\;to\;3.13\%\;and\;71.88\%\;(ST)\;to\;9.35\%$. The change of endometrium and breast were found 3 (CT) and 5 (ST) women, respectively. Most of women recognized that HRT is necessary $(70\%)$ for postmenopausal period but did not understand well the cardiovascular protective effect. In conclusion, hormone replacement therapy was effective in improving lipid profile, bone mineral density and menopausal symptoms in both continuous and sequential treatments with similar efficacy.

• Journal of Korean Society for Quality Management
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• v.43 no.3
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• pp.273-288
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• 2015

Purpose: In this study, we apply environmental stress screening (ESS) to battle management system (BMS) of a tank and use the ESS profile based on production process data, guided by MIL-HDBK-781/344/2164. Methods: To optimize ESS Profile of the BMS of a tank, we estimate ESS model parameters (e.g., defect density, screening strength) using primary production failure reporting and corrective action system (FRACAS) data of military supply contract firm. Results: First, we collect the Primary production FRACAS data of military supply contract firm. Second, we compute curve fitting approach to find patent defect density and latent defect density using FRACAS data. Third, we solve the equation of Defect Density(patent defect density + latent defect density)($D_{IN}$) and Screening Strength(SS) Using second step data. As a result of analysis according to the order, we calculate $D_{IN}$(Temperature stress case : 74.02, Vibration stress : 10.252) and : SS(Temperature stress case : 0.4632, Vibration stress : 0.4142) and confirm the Condition II-D based on MIL-HDBK-344. According to Condition II-D, it is necessary to modify existing ESS profile through decreasing the $D_{IN}$ and increasing the SS. Conclusion: Identification of defect causes through ESS approach reduce defect densities for production. It provides feedback to a lessons-learned data base to avoid similar problems on next generation tank BMS.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.413-416
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• 2008

Effects of extracts obtained from the flowers of Elsholtzia splendens on the serum lipid profile and hepatotoxicity in mice were investigated. Female ICR mice were given E. splendens ethanolic extract (ESEs) orally at a dose of 10 or 50 mg/kg BW for 50 days. Significant dose-dependent decreases in triglyceride and low-density lipoprotein (LDL)-cholesterol of serum were observed. In addition, ESEs prolonged the lag-time of LDL oxidation in vitro. In the serum of ICE mice given ESEs orally at 10 and 50 mg/kg BW, the serum levels of aspartate aminotransferase (AST) and lactic dehydrogenase (LDH) increased significantly, while total protein, albumin, creatinine, alanine aminotransferase (ALT), and total bilirubin did not change. Therefore, ESEs may be beneficial to human health, although it has some hepatotoxicity.

• Journal of The Korean Astronomical Society
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• v.42 no.2
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• pp.17-26
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• 2009

We estimate the enclosed mass profile in the central 10 pc of the Milky Way by analyzing the infrared photometry and the velocity observations of dynamically relaxed stellar population in the Galactic center. HST/NICMOS and Gemini Adaptive Optics images in the archive are used to obtain the number density profile, and proper motion and radial velocity data were compiled from the literature to find the velocity dispersion profile assuming a spherical symmetry and velocity isotropy. From these data, we calculate the the enclosed mass and density profiles in the central 10 pc of the Galaxy using the Jeans equation. Our improved estimates can better describe the exact evolution of the molecular clouds and star clusters falling down to the Galactic center, and constrain the star formation history of the inner part of the Galaxy.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.501-501
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• 2012

A 2.45 GHz electron cyclotron resonance (ECR) plasma source with a belt magnet assembly configuration (BMC) was developed for hyperthermal neutral beam (HNB) generation. A plasma source for high flux HNB generation should be satisfied with the requirements: low pressure operation, high density, and thin plasma. The ECR plasma source with BMC achieved high density at low operation pressure due to electron confinement enhancement caused by high mirror ratio and drifts in toroidal direction. The 2.45 GHz microwave launcher had a circularly bended WR340 waveguide with slits. The microwave E-field profile induced by the microwave launcher was studied in this paper. The E-field profile was a cups field perpendicular to B-filed at ECR zone. The optimized E-field profile and B-field were found for effective ECR heating.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.1 s.190
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• pp.37-46
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• 2007

The vibration environment essentially companied by vehicle operation on the ground is determined by the shape of road surface, which is called profile. This paper focuses on development of a profile and severity measurement system for unpaved test courses. In general, the profile and severity of unpaved road is an important issue in the reliability of endurance test. In order to measure unpaved road profile and severity, it is necessary to develop a profilometer system. The developed profilometer system is composed of data processing computer, power unit, air compressor and sensors(encoder, vertical gyro and laser displacement) This paper presents the measuring system configuration, measurement principle of road profile and analysis method of road characteristics used at CPG(Changwon Proving Ground) for this purpose.

• Journal of the Korea Furniture Society
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• v.23 no.4
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• pp.460-466
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• 2012

This study was conducted to investigate the surface hardness of thermally-compressed larch wood by compression set and temperature. The surface hardness of thermally-compressed larch wood increased with increasing compression set and temperature. For compression set 60%, the specific gravity was increased as 0.93. However, the surface hardness was lower value as 31.1 N/$mm^2$ compared with a similar specific gravity of the tropical timber. For density profile, less than compression set 40%, compression was observed mainly surface area. On the other hand, more than 50%, density profile variation was reduced by compression of central part. Results of this study indicate that thermally-compressed larch wood can be replace some imported hardwoods such as oak or cherry. However, thermally-compressed larch wood was difficult to replace the tropical timber being imported in terms of surface hardness.

• Korean Journal of Medicinal Crop Science
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• v.20 no.1
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• pp.42-46
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• 2012

Soy isoflavones have been suggested to improve bone loss and lipid profile in postmenopausal women and ovariectomized rats. In present study, we investigated the hypothesis that consumption of soybean, mung bean, cowpea and azuki bean has a beneficial effect on lipid profile which associates with bone mass in ovariectomized rats. Forty two female Sprague-Dawley rats were either sham-operated (Sham) or surgically ovariectomized (OVX). Sham and OVX groups were fed a regular AIN-93M diet, but ovariectomized rats with soybean (OS), mung bean (OM), cowpea (OC) or adzuki bean (OA) were fed AIN-93M diet replacing 35% of corn starch with powdered OS, OM, OC or OA for 10 weeks. Total- and LDL-cholesterol concentrations were significantly lower in Sham and OC groups than other OVX groups. There was significant negative association between total cholesterol concentration and bone mineral density (BMD) of tibia in only OC group. In conclusion, total-cholesterol concentration was significantly and negatively correlated with BMD in rats consumed cowpea, suggesting that the reduced cholesterol concentration may have a beneficial effect on bone mass.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.320-329
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• 2008

The influence of thermodynamic transition associated with transcritical nitrogen injection upon the flow structure was investigated to explore numerical simulation of the injectant dynamics of oxygen/hydrogen coaxial jet in liquid rocket engines. Single and coaxial nitrogen jets were treated by comparing the transcritical and perfect-gaseous conditions, wherein the numerical model was accommodative to the real-fluid thermodynamics and transport properties at supercritical pressures. The model was in the first place validated by comparing the results of transcritical nitrogen injection between calculations and available experiments. For a single jet under the transcritical condition, the nitrogen kept a relatively high density up to its pseudo-critical temperature inside the mixing layer, since it remains less expanding until heated up to its pseudo-critical temperature. Numerical analysis revealed that cryogenic jets exhibit strong dependence of specific enthalpy profile upon the associated density profile that are both dominated by turbulent thermal diffusion. In the numerical model, therefore, exact evaluation of turbulent heat fluxes becomes very important for simulating turbulent cryogenic jets under supercritical pressures. Concerning the coaxial jets due to transcritical/gaseous nitrogen injections, the density profile inside the mixing layer was again affected by the thermodynamic transition of nitrogen. However, hydrodynamic instability modes of the inner jet did not show significant differences by this thermodynamic transition, so that further study is needed for the mixing process downstream of the near injection position.