• Microbiology and Biotechnology Letters
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• v.20 no.1
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• pp.96-101
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• 1992

Two strains of polyvinyl alcohol (PVA) utilizing bacteria were isolated from the waste water and soil. These strains, G5Y and PW, were able to utilize PVA symbiotically as a carbon source, but could not utilize PVA separately. In the mixed culture of these strains, 0.5 percent of PVA was almost completely degraded in 3 days. Effect of degree of PVA polymerization on the its utilization was examined, and there was no remarkable difference among three kind of PVA (PVA 500, 1500, a d 2000). These bacteria were able to utilize PV,4 in the desizing waste water of factory as well as enrichment PVA medium. These strains, C5Y and PW, were identified as Pseudomonas cepucia and Pseudomonus pseudomallei, respectively, based on morpholofical and biological characteristics.

• The Journal of the Korea Contents Association
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• v.17 no.7
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• pp.571-578
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• 2017

In order to approach information system through smart device and pc, user has to authenticate him or herself via user authentication. At that time when user tries reaching the system, well-used user authentication technologies are ID/PW base, OTP, certificate, security card, fingerprint, etc. The ID/PWbased method is familiar to users, however, it is vulnerable to brute force cracking, keylogging, dictionary attack. so as to protect these attacks, user has to change the passwords periodically as per password combination instructions. In this paper, we designed and implemented a user authentication system using smartphone's USIM without using password while enhancing security than existing ID / PW based authentication technology.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.4
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• pp.42-47
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• 2008

The power control system of Smart UAV is similar to the propeller pitch governing concept of turboprop aircraft. The pilot adjusts the engine power directly and the pitch governor controls the propeller pitch to maintain the propeller rotational speed. The electronic engine controller(EEC) of PW206C engine developed for helicopter is not fit for the power control concept of Smart UAV, and therefore the manual back-up system of PW206C engine is used for the engine power control of Smart UAV. Engine performance estimation program is used to predict the control range of power lever angle(PLA) according to the variation of engine output shaft speed, flight altitude and flight speed. These data provide a guide for the PLA control in manual mode operation.

• Communications of the Korean Mathematical Society
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• v.33 no.2
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• pp.571-580
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• 2018

The object of the present paper is to prove the non-existence of pseudo projective Ricci symmetric spacetimes $(PW\;RS)_4$ with different types of energy momentum tensor. We also discuss whether a fluid $(PW\;RS)_4$ spacetime with the basic vector field as the velocity vector field of the fluid can admit heat flux. Next we consider perfect fluid and dust fluid $(PW\;RS)_4$ spacetimes respectively. Finally we construct an example of a $(PW\;RS)_4$ spacetime.

• Journal of the Korean Chemical Society
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• v.52 no.1
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• pp.23-29
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• 2008

Simple Keggin type tungsten and molybdenum heteropoly acids, H3PW12O40 and H3PMo12O40, were usedas water-tolerant catalysts for the oxidation of alcohols with 34% hydrogen peroxide in normal drinking water. Accordingto our findings, H3PW12O40 may be used as a simple, effective, and cheap catalyst for this type of transformation in nor-mal drinking water with excelent yields. Efects of diferent solvents at 25-80oC and changing concentration of catalystand substrate on the reaction progress were also studied.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.563-565
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• 1993

This paper describes ozone concentration and discharge characteristics in flowing $O_2$ with variation of Re at high voltage nozzle(HVN). HVN type ozonizer is equipped with ten nozzle. The important conclusions obtained from this paper are as follows. For constant pulse width(Pw) and pulse frequency(Pf) the more Re increases, the higher corona onset voltage(Vc) rise. Vc is inversely proportional to Pw and Pf. Ozone concentration($O_{3con}$) increases with less Re for constant Pw and Pf. $O_{3con}$ increases with less Pw. $O_{3con}$ is proportional to Pf.

• Bulletin of the Korean Chemical Society
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• v.16 no.12
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• pp.1176-1179
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• 1995

1H NMR spectra of pyridine, α-, β-, and γ-picoline coordinated to the paramagnetic heteropolyanion [Ni3(PW9O34)2]12- (P2Ni3) are reported. NMR lines are assigned to [Ni3(ptl)n(PW9O34)2]12- (n=1, 2 or 3; ptl=pyridine-type ligand) on the basis of their [P2Ni3]/[ptl] dependence. The formation constants for γ-picoline complexes at 25 ℃ are K1=80, K2=610, and K3=190 L mol-1. The monopicoline complex has greater affinity for γ-picoline than P2Ni3. A degradation product, [Ni2(WO2)(PW9O34)2]12-, was also identified at low pH by measuring the NMR spectrum of pyridine coordinated to it. The isotropic NMR shifts come mainly from the contact interaction due to σ-electron delocalization.

• The Journal of Korean Medicine
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• v.38 no.4
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• pp.62-81
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• 2017

Objectives: As interests in the beauty of skin is growing continuously, more people are focusing on white and clean skin. Melanin is the major factor that determines skin color. The abnormal concentration of melanin causes various skin diseases such as vitiligo, freckles, and melasma. This study investigated the inhibitory effect of Eriobotryae Folium extracts (EF) with phreatic water (PW) on the melanin synthesis. Methods: The effect of EF on melanin synthesis was evaluated by using mouse melanoma cells (B16F10). To define the mechanisms, real-time PCR and western blot were used. We also evaluated the inhibitory effects of EF and PW on melanin synthesis by using HRM-2 melanin-possessing hairless mice. After UVB irradiation, melanin differences between the skin parts that were treated and untreated with EF and PW. Levels of mRNA were measured by real-time quantitative PCR and histological analysis of the dorsal skin was conducted by hematoxylin and eosin staining. Results: EF inhibited various mechanisms of melanogenesis, and the effect was increased when combined with PW. In vitro experiments have shown that EF inhibited the expressions of tyrosinase related protein-1 (TRP-1) mRNA, tyrosinase mRNA, microphthalmia-associated transcription factor (MITF) mRNA and the tyrosinase inhibitory activation, but it stimulated the extracellular regulated kinase (ERK) mRNA expression. In vivo experiments have shown that EF prevented melanogenesis in the mice dorsal skin and inhibited TRP-1 mRNA expression. Also these effects were increased when combined with PW. Conclusions: EF and PW might be a new and effective treatment for whitening and treating pigmentation of skin.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.469-479
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• 2003

A novel branched wax has been developed for the control of the hardness of oil-wax gels. Using this wax, glossier application and smoother texture but tough lipstick can be obtained. Oil-wax gels are oily solids composed of liquid and crystalline solid oils (waxes). They are widely used in various cosmetic products, especially lipsticks. The control of gel hardness is one of the most important techniques in improvement of the lipstick quality. Addition of small amounts of commercial branched paraffin wax (e.g. microcrystalline wax, b-PW) to n-paraffin wax (n-PW) has been commonly used to increase gel hardness. However, gel hardness is very sensitive to the quantity of b-PW and the gel obtained is not always hard enough for practical use. In this study we examined the relationship between the gel hardness and the properties of the wax crystal in the gel. We have found that, when b-PW is added to n-PW, the wax crystal size becomes smaller (hardening the gels) and its crystallinity is decreased (softening the gels) simultaneously. Considering this result, we have developed a novel branched wax, Bis(polyethylenyl)- tetramethyldisiloxane (named ESE). ESE molecules are composed of a central tetramethyldisiloxane unit (branch unit) with polyethylene units at both ends. The central unit may suppress crystal growth while the ends are expected to prevent a decrease in wax crystallinity during crystallization. When ESE is added to n-PW, the wax crystal obtained becomes smaller without decreasing in crystallinity; consequently, the gel hardness is dramatically increased. By using ESE, the total amount of wax in a lipstick can be decreased by 30％ without spoiling the stick toughness, thereby achieving glossy application and smooth texture.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.205-214
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• 2017

In this paper, we proposed an iris-based authentication for smart healthcare service in secure telemedicine system. The medical and healthcare information's are very important data in telemedicine system from privacy information. thus, the proposed system provides a secure and convenient authentication method than the traditional ID/PW authentication method to a telemedicine system for age-related chronic diseases. When considering the peculiarities of the use of age-related chronic diseases convenience and healthcare environments, the proposed approach is difficult to secure than traditional ID/PW authentication method with the appropriate means to easily change when stolen or lost to others. In addition, the telemedicine system for the smart healthcare services is one of the types of privacy sensitive medical and health data. it is very important security needs in telemedicine system. Thus we protocol are offer high confidentiality and integrity than existing ID/PW method.