• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.334-336
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• 2000

In Korea, the CCGTs have been installed to about 25% of the total generating capacity. Generally CCGTs determine the System Marginal Prices(SMP) in Cost Based Generation Pool. So the scheduling of CCGTs is very important in daily generation scheduling. This paper describes the scheduling of CCGTs which considers the operating characteristics of them. We use lagrangian relaxation method which decomposes the unit committment problem into the subproblems of the individual unit. In the CCGT subproblem, we define the cost function of CCGT in two way. In Case study, the daily generation scheduling is performed using the data of Korean thermal system.

• Journal of Magnetics
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• v.20 no.4
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• pp.342-346
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• 2015

The nuclear magnetic resonance of the $^{23}Na$ nucleus in a $NaBrO_3$ single crystal was investigated at the temperature range of 200 K~410 K. The tendencies of temperature dependence of the nuclear quadrupole coupling for the two magnetically inequivalent Na(I) and Na(II) centers are found to be opposite to each other. The nuclear spin-lattice relaxation mechanism of $^{23}Na$ in the $NaBrO_3$ crystal is investigated, and the result revealed that the Raman process is dominant in the temperature range investigated. The relaxation process of the $^{23}Na$ nuclear spins was well described by a single exponential function in time. The $T_1$ values of the $^{23}Na$ nuclei in the $NaBrO_3$ single crystal decreased with increasing temperature. The calculated activation energy for the $^{23}Na$ is $0.032{\pm}0.002eV$.

• Journal of the Korean housing association
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• v.1 no.1
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• pp.49-64
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• 1990

Studies on housing concept currently activated by environmental psychology are in its early stage of developement. The trends can be characterized as case oriented, phenomenological, and exploratory. The purpose of this research was to explore empirically the housing concept from residents living in multi family housing complex through their verbal expressions. Subjects were 63 housewives of middle class households in Junggae area. Interview technique with open questions about housing concept and images was used. The responses were analyzed using content analysis in which episode was the analysis unit. Relaxation appeared the most important aspect of housing concept This seemed to imply the need for escaping from the modern city life with too much stimulus or stress. Answers on specific images considered desirable to keep and continue from past traditional housing to future housing showed their strong need for natural green environment such as garden and park. This supported the concept of relaxation as a major function of modern housing and showed a specific alternative mean to satisfy the relaxation concept.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.7
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• pp.279-286
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• 2002

Linear and nonlinear complex permittivities were measured for copolymers of vinylidene cyanide(VDCN) with vinyl acetate(VAc), vinyl propionate(VPr), vinyl bezoate(VBz), styrene(St) and methyl methacrylate(MMA). Experimental results are well fitted by the function (equation omitted) except at low frequency where dc conduction dominates. The analysis of dielectric relaxation mechanism by combined knowledge about linear and nonlinear dielectric permittivities and dipoles give us informations about electrical and thermal motions in these copolymers. According to the analysis it could be found that the variation for temperature of the dielectric relaxation strength in these copolymers is related to the interaction between dipoles and the nonlinear dielectric effect factor R$_{s}$ is proportional to square of the dipolar correlation factor R$_{p}$././.

• Journal of Magnetics
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• v.19 no.2
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• pp.116-120
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• 2014

The spin-lattice relaxation time, $T_1$, for $^{69}Ga$, $^{71}Ga$, and $^{75}As$ nuclei in GaAs:$Mn^{2+}$ single crystals was measured as a function of temperature. The values of $T_1$ for $^{69}Ga$, $^{71}Ga$, and $^{75}As$ nuclei were found to decrease with increasing temperature. The $T_1$ values in GaAs:$Mn^{2+}$ crystal are similar to those in pure GaAs crystal. The calculated activation energies for the $^{69}Ga$, $^{71}Ga$, and $^{75}As$ nuclei are 4.34, 4.07, and 3.99 kJ/mol. It turns out that the paramagnetic impurity effect of $Mn^{2+}$ ion doped in GaAs single crystal was not strong on the spin-lattice relaxation time.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.230-232
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• 1987

Nitrogen-14 quadrupolar relaxation has been observed in the amino proton nmr spectra of TA in acetone and methanol solutions over the temperature range $-83^{\circ}C\; to\;+35^{\circ}C.$ The proton nmr lineshapes were analyzed to yield a $^{14}N$ spin lattice relaxation time $(T_1)_N$ as a function of temperature. Activation energies and correlation times at $25^{\circ}C$ for the molecular reorientation in the two solution phases have been calculated and the results are discussed.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.33-37
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• 1992

Information about $^{14}N$ relaxation rates is obtained for thioacetamide (TA) in acetone from a detailed line-shape analysis of the $^1H$ resonance signal of $NH_2$ group. The effect of pressure and of temperature were investigated, and activation energies for molecular reorientation are given. And also $^1H$ relaxation rates of $NH_2$ group of TA as a function of pressure and temperature are obtained. These results are discussed with the results for the $^{14}N$ relaxation of amine group.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.3
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• pp.263-270
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• 2000

To evaluate the involvement of nitric oxide production on the endothelium-dependent relaxation in diabetes, we have measured vascular and endothelial function and nitric oxide concentration, and the expression level of endothelial nitric oxide synthase in the streptozotocin-induced diabetic rats. Diabetic rats were induced by the injection of streptozotocin (50 mg/kg i.v.) in the Sprague-Dawley rats. Vasoconstrictor responses to norepinephrine (NE) showed that maximal contraction to norepinephrine $(10^{-5}\;M)$ was significantly enhanced in the aorta of diabetic rats. Endothelium-dependent relaxation induced by acetylcholine was markedly impaired in the aorta of diabetic rats, these responses were little improved by the pretreatment with indomethacin. However, endothelium-independent relaxation induced by nitroprusside was not altered in the diabetic rats. Plasma nitrite and nitrate $(NO_2/_3)$ levels in diabetic rats were significantly lower than in non-diabetic rats. Western blot analysis using a monoclonal antibody against endothelial cell nitric oxide synthase (eNOS) revealed that the protein level was lower in the aorta of diabetic rats than in non-diabetic rats. These data indicate that nitric oxide formation and eNOS expression is reduced in diabetes, and this would, in part, account for the impaired endothelium-dependent relaxation in the aorta of streptozotocin-induced diabetic rats.

• The Journal of Korean Obstetrics and Gynecology
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• v.31 no.1
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• pp.43-56
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• 2018

Objectives: This study was designed to investigate the basis for developing the herbal decoction that may help promote healthy blood vessels in accordance with the basic principles of Korean medicinal materials. Methods: In this study, we investigated the vascular relaxation effects of fifty herbal decoctions on vascular response in isolated thoracic aorta of phenylephrine-preconracted rats. Results: The results of identify the vascular relaxation effect of fifty herbal decoctions provided by Korea Institute of Korean Medicine, twenty-one herbal decoctions showed vascular relaxation effects. Among them, four herbal decoctions, Mahwang-tang (麻黃湯), Samchulgeonbi-tang (參朮健脾湯), Cheonwangbosim-dan (天王補心丹), and Socheonglyong-tang (小靑龍湯), with showed significantly concentration-dependent vasodilation was examined. Vascular relaxation level are $84.02{\pm}4.70$, $79.39{\pm}13.9$, $51.26{\pm}12.56$, and $54.73{\pm}15.8%$, respectively (P<0.05, 0.01, and 0.001). Conclusions: Thus these results provide a basic data for the treatment of the impairment of vascular function and blood pressure in traditional Oriental medicine.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.426-429
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• 1999

Many similar class components are stored in object-storage but the object-storage has needed the retrieval function of correct component for reuse. Accordingly this paper designed the class component retrieval viewer of the object-storage by using the improved spreading activation strategy. Object-storage has made up of information of inheritance relation, superclass, subclass, and we defined the queries about each class function. Also we specified connectionist relaxation of the each class and query, finally we gained retrieval result which showed highest activation value order of class component information including the query function.