• Journal of the Korean Data and Information Science Society
• /
• v.22 no.2
• /
• pp.287-296
• /
• 2011

Thirty six female students participated in the experiment of the fat mass weight loss. they kept diary for foods they ate every day, took a picture of the foods, transmitted the picture to the experimenter by the camera phone, and consulted him about fat mass loss once a week for 8 weeks period. Fat mass weight and its related factors of the students had been measured repeatedly every week during 8 weeks, The repeated measurement data were used for applying various random coefficient models. And hence optimal random coefficient model was selected. From the optimal model, the baseline, body mass index, diastolic blood pressure, total cholesterol and time of the fixed factors were very significant. The fixed quadratic time effect existed. The variance components corresponding to the subject effect, linear time effect of the random coefficients were all positive. Thus random coefficients up to the linear terms were considered as the optimal model. The treatment effect reduced the weight loss to an average of 2.1kg at the end of the period.

• Journal of Digital Contents Society
• /
• v.16 no.3
• /
• pp.355-363
• /
• 2015

In this paper, we propose a system for controlling the seat of the electric wheelchair depending on the slope of the terrain in real time by using the ATmega smart control based on the board. Smart control board includes a gyro sensor, an acceleration sensor and Tilt sensor, when the electric wheelchairs pass slope of the terrain, they use three sensors to identify terrain configuration in real time. We also applied the Complementary Filter in the gyro sensor and acceleration sensor, so the electric wheelchairs know the exact terrain by solving the interference during the movement. Based on this, the noise power wheelchair due to the movement will be reduced, the seat continues reliably movement without being vibration. In this paper, providing an application on the smart phone platform for the convenience of users who are not familiar with how to use electric wheelchairs, they can easily control wheelchairs. Control platform of the smart phone is able to monitor the electric wheelchair in real-time, with regard to pressure prevention, help the slope of the seat to be arbitrarily controlled.

• 유체기계공업학회:학술대회논문집
• /
• 2004.12a
• /
• pp.140-150
• /
• 2004

In this study, the effect of relative position of the blade for the fixed vane has been investigated on blade surface heat transfer. The experiments were conducted in a low speed stationary annular cascade, and heat transfer of blade was examined for six positions within a pitch. Turbine test section has one stage composed of sixteen guide vanes and blades. The chord length of the tested blade is 150 mm and the mean tip clearance of the blade having flat tip is about $2.5\%$ of the blade chord. For the detailed mass transfer measurements on the blade surfaces, a naphthalene sublimation technique was used. The inlet flow Reynolds number is fixed to $1.5{\times}10^5$. Complex heat transfer characteristics are observed on the blade surface due to various flow characteristics, such as separation bubble, relaminarization, transition to turbulence and leakage vortices. The distributions of velocity and turbulence intensity change significantly with the relative position due to the blockage effect of the blade. This causes the variation of heat transfer patterns on the blade surface. The results show that the flow near the leading edge get highly disturbed and deflected toward the either side of the blade when the blade leading edge is positioned close to the trailing edge of the vane. Therefore, separation bubble disappears on the pressure side and overall heat transfer on the relaminarization region is increased. But, due to reduced tip gap flow at the upstream region, the effect of leakage flow on the upstream region of the blade surface is weakened. Thus, the heat transfer characteristics significantly change with the blade positions.

• Solar Energy
• /
• v.18 no.3
• /
• pp.161-167
• /
• 1998

The effects of some additives(black liquor, wood and lignin) on the conversion of coal and product were investigated in the lab-scale, high pressure reacting system around $375^{\circ}C$. The addition of lignin to coal during liquefaction significantly increased the depolymerization of coal and enhanced the quality of the liquid products. Coprocessing of wood and coal at $400^{\circ}C$ increased yield of liquid product about 8%, but higher temperature above $400^{\circ}C$ reduced liquid product due to increase of gas products. The addition of black liquor resulted in an enhancement in coal conversion yields, however, the observed increase is lower than that obtained in the presence of NaOH because lignin present in black liquor is not very effective due to the $OH^-$ presence.

• Journal of Ginseng Research
• /
• v.38 no.1
• /
• pp.22-27
• /
• 2014

Background: Research has been conducted with regard to the development of methods for improving the pharmaceutical effect of ginseng by conversion of ginsenosides, which are the major active components of ginseng, via high temperature or high-pressure processing. Methods: The present study sought to investigate the anticancer effect of heat-processed American ginseng (HAG) in human gastric cancer AGS cells with a focus on assessing the role of apoptosis as an important mechanistic element in its anticancer actions. Results and Conclusion: HAG significantly reduced the cancer cell proliferation, and the contents of ginsenosides Rb1 and Re were markedly decreased, whereas the peaks of less-polar ginsenosides [20(S,R)-Rg3, Rk1, and Rg5] were newly detected. Based on the activity-guided fractionation of HAG, ginsenoside 20(S)-Rg3 played a key role in inducing apoptosis in human gastric cancer AGS cells, and it was generated mainly from ginsenoside Rb1. Ginsenoside 20(S)-Rg3 induced apoptosis through activation of caspase-3, caspase-8, and caspase-9, as well as regulation of Bcl-2 and Bax expression. Taken together, these findings suggest that heat-processing serves as an increase in the antitumor activity of American ginseng in AGS cells, and ginsenoside 20(S)-Rg3, the active component produced by heat-processing, induces the activation of caspase-3, caspase-8, and caspase-9, which contributes to the apoptotic cell death.

• Journal of Ginseng Research
• /
• v.38 no.4
• /
• pp.244-250
• /
• 2014

Background: Panax ginseng has distinct and impressive health benefits, such as improved blood pressure and immune system functioning. Rg3-enriched Korean Red Ginseng (REKRG) isolated from Korean Red Ginseng contains a high percentage of Rg3. Methods: In this study, we examined the effects of REKRG on endothelial cell nitric oxide synthase (eNOS) activation and adhesion molecules in endothelial cells and vascular function in rats. Results: REKRG dose-dependently increased eNOS phosphorylation and nitric oxide (NO) production in endothelial cells. In addition, REKRG markedly inhibited the tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$)-mediated induction of intercellular adhesion molecule (ICAM)-1 and cyclooxygenase (COX)-2 expressions in endothelial cells. REKRG improved endothelium-dependent vasorelaxation in the Wistar-Kyoto (WKY) rat and spontaneously hypertensive rats (SHRs) compared with controls. Furthermore, REKRG treatment for 6 weeks increased serum NO levels and reduced the mean aortic intima-media thickness compared with controls. Conclusion: Taken together, these results suggest that REKRG increased vascular function and improved immune system functioning. Therefore, REKRG is a very useful food for preventing or improving various cardiovascular diseases.

• Korean Journal of Computational Design and Engineering
• /
• v.13 no.2
• /
• pp.139-152
• /
• 2008

In order to survive worldwide competition, today's industries are experiencing strong pressure to introduce higher quality products with lower cost and shorter lead-time. Therefore, the role of design in the process of product development is increasing in significance. In this research, two methods for improving the design capability are proposed: construction of design environment and design automation using 3D CAD system. The designers and design process are the core of product design using 3D CAD system. In order to maximize the design performance, construction of the design environment including selection of a suitable system, designer training for best use of the system, establishment of an efficient design process, and stabilization of the environment are required. A method is suggested to construct design environment by systematizing the contents of the projects and consulting experiences carried out for various categories of business such as electronic devices, motorcycles, electricity parts, sanitary wares, injection molds, and die casing molds. Design automation helps reduce tedious and time-consuming jobs, simplify complicated and error-prone modeling and drawing works to shorten the lead time and improve the product quality. To develop a design automation system, understanding the process and the related knowledge on design are very important before implementing the system using API provided by 3D CAD system. In this research, an eight-step procedure is proposed for the development of a design automation system. These eight steps are analysis of needs, determination of specification, verification of specification using 3D CAD system, inspection of related API functions, programming, field test, application in practice, and maintenance. A case study in which five design automation systems in the design of turbine generators using the proposed method is introduced in detail. These systems play important roles in the generation of various output items including 3D models, drafts, material information, and NC data. The case study shows how effectively the design time is reduced and the quality improved using those systems.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.5
• /
• pp.399-402
• /
• 2000

Very little information is known on the canning of fishery products by vacuum pack. In this paper, some fundamental process conditions for the canning of fishery products were investigated. Moisture-controlled mackerel pike, shrimp and oyster were packed in lacquered cans with spice and additives. After sealing, pressure of the cans were reduced by do-aeration through specially designed gas-tight silicone rubber plug previously attacked to the lid. On this investigation, vacuum can prior to thermal processing were set up to 15, 30, 45 and 60 cmHg, The higher vacuum in cans showed the more quick heat transfer in thermal processing. tinder 60 cmHg vacuum, the heat transfer was more quick than that of the conventional water packed products, Under 15 cmHg, however, the heat transfer was markedly increased by air which acted as an insulator in conductive heat transfer. These results demonstrated that high vacuum was essential secure for the heat processing in vacuum pack.

• Journal of dental hygiene science
• /
• v.18 no.3
• /
• pp.147-154
• /
• 2018

This study aimed to evaluate the antimicrobial effects of Acanthopanax sessiliflorum fruit (ASF; Ogaza) extracts on Streptococcus mutans and Streptococcus sobrinus, which are agents that cause dental caries, and on Streptococcus mitis and Streptococcus salivarius, the microbial flora of the oral cavity. The ASF extracts obtained using 70% ethanol were fractionated in the order of ethyl acetate and n-Butanol, concentrated under reduced pressure, and lyophilized to give powdery solvent extracts. The antimicrobial activity of ASF extracts from each solvent was examined using the disk diffusion method. As a result, only those extracts obtained using an ethyl acetate solvent showed antimicrobial activity. These extracts were selected, and the minimum inhibitory concentration was measured by disk diffusion method at various extract concentrations. Results showed a minimum inhibitory concentration of 32 mg/ml. The viable cell count was measured to confirm the minimum bactericidal concentration. Results showed a minimum bactericidal concentration of 64 mg/ml. In the cytotoxicity test using normal human dermal fibroblast cells, the absorbance value of the test group was similar to that of the control group at 0.64, 1.28, and 6.4 mg/ml. The bacteria and their colonies were examined using a scanning electron microscope. Boundaries between the antimicrobial activity region and non-antimicrobial activity region were observed around the paper disk, which was immersed in the extract with 32 mg/ml concentration. Bacterial colonization was not observed in the area with antimicrobial activity. This finding suggests that ASF extracts can inhibit the growth of some microorganisms in the oral cavity, in addition to the effects of these extracts known to date. In particular, ASF extracts may be used as a preparation for preventing dental caries by adding the extract to the toothpaste or oral mouthwash.

• Journal of Korean Society of Water and Wastewater
• /
• v.21 no.1
• /
• pp.123-130
• /
• 2007

The effects of hydrogen peroxide treatment on the reduction of waterworks sludge were investigated in this study. Sludge treated by peroxidation $H_2O_2$ oxidation) was dewatered using a pressure filter at 3atm. It was observed that $H_2O_2$ treatment at the acidic condition significantly reduce both cake water content and specific resistance to filtration (SRF), indicating the enhancement of dewaterability and filterability. The filterability by hydrogen peroxide treatment at pH 3.5 was better than acidic treatment and became comparable with polymer conditioning. The sludge filterability evaluated by SRF was optimal at a dose 2ml $H_2O_2$/sludge($0.02g\;H_2O_2/gTS$) after adjusting of pH to 3.5. The $H_2O_2$ oxidation at pH 3.5 also produced even more dewatered cake when compared with polymer conditioning. The reduction rate of sludge mass at an optimal condition showed 34% compared with untreated sludge. The effects of peroxidation on sludge properties including zeta potential, bound water and particle size were also evaluated. Peroxidation at the acidic condition reduced both bound water and zeta potential. By $H_2O_2$ combined with sulfuric acid leached iron caused Fenton's reaction, which showed a potential to significantly reduce the amount of solids mass and to produce more compact cake with higher filterability.