• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.1
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• pp.8-15
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• 2005

This study concerns the characteristics of helical flow in a concentric and eccentric annulus with a diameter ratio of 0.52 and 0.9, whose outer cylinders are stationary and inner ones are rotating. Pressure losses and skin friction coefficients have been measured for fully developed flows of water and $0.2\%$ aqueous of sodium carboxymethyl cellulose(CMC), respectively, when the inner cylinder rotates at the speed of $0\~500$ rpm. The effect of rotation on the skin friction coefficient is significantly dependent on the flow regime. In all flow regimes, the skin friction coefficient is increased by the inner cylinder rotation. This study shows the change of skin friction coefficient and wall shear stress corresponding to the variation of rotating speed of the inner cylinder, radius ratio, eccentricity, and working fluids.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.769-772
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• 2000

Fish oil has abundant highlly unsaturated fatty acids such as EPA and DHA. Therefore, fish oil is very susceptible to peroxidation. Adding any antioxidants to fish oil is acceptable to prevent the peroxidation. However, nontoxic and strong naturally occurring antioxidants for fish oil was not developed. ${\alpha}-tocopherol$ is one of useful natural antioxidants, but it is not good to prevent the fish oil peroxidation. In this study, we examined the development of microencapsulated squid liver oil product to prevent effectively peroxidation of the fish oil. The acceptable materials for encapsuling the squid liver oil were gum arabic and gelatin. The ultimate encapsulation rate of squid liver oil was 45.5%.

• Journal of Power Electronics
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• v.17 no.1
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• pp.88-95
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• 2017

To reduce common-mode voltage (CMV), various reduced CMV pulse width modulation (RCMV-PWM) algorithms have been proposed, including active zero state PWM (AZSPWM) algorithms, remote state PWM (RSPWM) algorithms, and near state PWM (NSPWM) algorithms. Among these algorithms, AZSPWM algorithms can reduce CMV, but they increase the number of switchings compared to the conventional space vector PWM (CSVPWM). This paper presents a new AZSPWM algorithm for reductions in both the CMV and total number of switchings in BLAC motor drives. Since the proposed AZSPWM algorithm uses only active voltage vectors for motor control, it reduces CMV by 1/3 compared to CSVPWM. The proposed AZSPWM algorithm also reduces the total number of switchings compared to existing AZSPWM algorithms by eliminating the switchings required from one sector to the next. The performance of the proposed algorithm is verified by analyses, simulations, and experimental results.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.693-704
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• 2007

지금까지 사이버문화에 대한 연구는 해당 문화의 가장 큰 특성 중인 익명성과 그것이 개별 이용자들의 정체성에 미치는 영향에 대한 많은 관심이 있어왔다. 최근 주목을 받고 있는 싸이월드나 블로그 등 CMC환경에서 매체가 일반적으로 여성의 라이프스타일 및 여성성과 연관되어 정체성의 구성에 영향을 미치게 되며, 이러한 이용 형태를 마케팅과 접목하여 높은 여성 참여와 구매력을 이끌어내고 있다. 반면 온라인게임은 남성 중심의 매체로써의 특징을 가지고 있으며, 상대적으로 여성의 온라인게임 이용 행태 분석 및 마케팅 전략 연구가 미흡하였다. 온라인게임에서 여성 이용자의 참여나 구매력을 이끌어 내기 위해서는 우선적으로 남성 중심적 매체에서 여성 온라인게임 유저의 이용 행태 분석 이 선행되어야 하며, 이를 통하여 여성의 온라인게임 소비 패턴과 특성을 파악하고, 나아가 고객 충성도, 구매력과의 관련성 속에서 마케팅적 시사점을 도출하여야 할 것이다. 본 연구는 온라인게임 여성 유저의 심층 인터뷰를 통하여 우선적으로 연령별 게임 이용 패턴 - 게임이용 장소, 초기 진입 방식, 커뮤니티 활동, 아이템 구매 형태 등 - 에 대해 알아보고, 다음으로 여성 유저의 게임 플레이 방식으로 게임 내 캐릭터의 전유 방식(몰입)과 게임 플레이 스타일을 고찰하고자 한다. 이때 여성의 온라인게임 이용 방식이 남성적 매체라는 구조적 공간 내에서 여성의 성적 특성이 온라인게임 소비 행태에 어떠한 영향을 미치며, 또한 여성 유저의 이용 방식에 따라 고객 충성도에 미치는 효과에 대해 알아보도록 한다.

• KSBB Journal
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• v.14 no.6
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• pp.737-741
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• 1999

Phenanthrene degrading bacteria were isolated from the petroleum contaminated soil near an oil tank. Four of 15 strains decreased surface tension of culture broth of phenanthrene-containing minimal media. H6, one of the isolated bacteria decreased surface tension of culture broth below 33 dyne/cm during growth on glucose. H6 was identified as Bacillus subtilis and biosurfactant produced by H6 was lipopeptide. The biosurfactant was produced at 0.13 g/L in the mineral medium containing 2% glucose. Critical micelle concentration(CMC) of the biosurfactant was 52 mg/L. Foaming power was similar to Tween 80 and dispersing power was superior to Tween 80m SDS and Brij30. High thermal stability and emulsion index were also observed.

• Journal of the Korean Home Economics Association
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• v.29 no.3
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• pp.47-59
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• 1991

This study wa performed to investigate the effects of dietary protein and fiber on the lead and protein metabolism in lead poisoning rats. Seventy male rats of Sprague-Dawley strain weighing 172$\pm$2g were blocked into 14 gropus according to body weight. Protein(casein) was given at levels of 15 or 40%, and fibers(pectin, cellulose and CMC) were given at levels of 0, 4 or 10%. The results are summarized as follows: 1. Food intake, weight gain and food efficiency ratio(FER) in groups fed high protein diets were higher than those in low protein groups. Liver weight in groups fed no dietary fiber was higher than that of animals fed fiber. Kidney and femur weights were greater in high protein groups. Tibia and femur lengths, and tibia weight were not significantly different among groups. 2. Hemoglobin content and hematocrit values showed no significant differance with dietary factors. 3. Total protein contents of serum and liver showed no significant difference, but tended to increase with increasing dietary protein level. Both daily urinary and fecal nitrogen excretions in high protein groups were higher than those in low protein groups. Especially daily fecal nitrogen excretions in high dietary fiber groups were significantly high. Body nitrogen absorption rate was the highest in animals fed no fiber. 4. Pb levels in blood, liver, kidney and bone tended to decrease with high dietary protein and fiber levels. Especially Pb level of kidney was high in all groups. Daily urinary Pb excretion showed no significant difference with dietary factors, but fecal Pb excretion increased significantly in high protein and fiber groups.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.337-340
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• 2002

The present experimental and numerical investigations are performed for the characteristics of transitional flow in a concentric annulus with a diameter ratio of 0.52, whose outer cylinder is stationary and inner one rotating. The flow field of an annulus has been numerically solved using a finite volume method. The pressure losses and Skin-friction coefficients have been measured for the fully developed flow of water and $0.2{\%}$ aqueous solution of sodium carboximethy1 cellulose (CMC), respectively at inner cylinder rotational speed of $0{\~}600rpm$. The transitional flow has been examined by the measurement of pressure losses to reveal the relation of the Reynolds and Rossby numbers with the skin-friction coefficients. The occurrence of transition has been checked by the gradient changes of pressure losses and skin-friction coefficients with respect to the Reynolds numbers. Consequently the critical(axial-flow) Reynolds number decreases as the rotational speed increases. Thus, the rotation of inner cylinder promotes the early occurrence of transition due to the onset of Taylor vortices.

• Korean journal of food and cookery science
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• v.12 no.1
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• pp.92-98
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• 1996

This experiment was carried out to investigate the effective additives and amount of addition in order to improve the quality of chou made with rice flour. The four emulsifiers and four thickeners were used as the additives in this test. The chou was formed with rice flour without the additives. There were not significantly differences in the sensory evaluation between choux of rice flour of non-additives and the additives, but the emulsifiers treatment increased the expansion capacity of paste. Thickeners did not improve the quality of choux. The hardness of pastes were increased and the cavities in choux were not formed in addition of high amount of thickeners. The mixture of two kinds of emulsifiers, the mixture of emulsifiers and a thickener did not improve of choux quality compared to the addition of emulsifier. The best quality of chou was obtained from 0.6% of lecithin.

• YAKHAK HOEJI
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• v.35 no.4
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• pp.319-325
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• 1991

Aluminum phosphate gel was synthesized by reacting aluminum sulfate as a soluble aluminum salt to tribasic sodium phosphate in this study. The optimal synthesis conditions based on the yield of product were investigated by applying Box-Wilson experimental design. It was found that optimal synthesis conditions were as follows: Reaction temperature; $61~71^{\circ}C$, concentration of two reactants; 12.27~13.83%, concentration ratio of two reactants; [AI$_{2}$(SO$_{4}$)$_{3}$]/[Na$_{3}$PO$_{4}$]= 0.5, reaction time; 10.9~12.1 minutes, drying temperature of product; $60~72^{\circ}C$. Aluminum phosphate gel prepared by the optimal synthesis conditions was suspended with four types of natural and synthetic gums at the concentration of 0.375~1.5wv%. Their Theological properties of aluminum phosphate gels were examined with Haake-Rotovisco RV 20 rotational viscometer. It showed that the higher concentration of suspending agents and lower temperature, the higher viscosity. Aluminum phosphate gel suspended by pectin and agar showed plastic flow with rheopexy, and their gels suspended by sodium alginate and sod. CMC showed plastic flow with thixotropy.

• Journal of the Korea Society for Simulation
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• v.16 no.2
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• pp.9-15
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• 2007

As the Internet grows and the mass multimedia data become popular, the storage system migrates from DAS, where the storage and the server are directly connected, to SAN and NAS. SAN connects the storages with a separate network, and NAS provides only file services, connects the storages with IP network. However, SAN and NAS can not fulfill the needs for companies if used separately, thus are asked to be integrated. In this research, we propose an efficient data sharing method which employees the concept of GMC, Croup Master Cache for the integrated environment of SAN and NAS. GMC is based on MCI, Metadata server and Cluster system Integration, but tries to solve the high expansion cost problem with MCI. We introduce the basic concept of GMC, compare the performance of GMC with that of MCI using computer simulation.