• Korean Journal of Materials Research
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• v.14 no.9
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• pp.659-663
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• 2004

Magnetite was prepared by wet method and oil-based magnetic fluid also was prepared by its magnetite. Ahead of making magnetite, we investigated the variation of physical properties for changing $Fe^{3+}/Fe^{2+}$. Through the variation of the process mixing time, pH, magnetite content, we made magnetic fluid of magnetite. We examined the magnetic and frequency property by a toroidal mold. In result $Fe^{3+}/Fe^{2+}=1.2$, over the minute mixing time property of magnetite, Ms was 61.98 emu/g. Moreover, the B-H loop result indicated that the magnetic fluid followed paramagnetic behavior.

• Bulletin of the Korean Mathematical Society
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• v.50 no.1
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• pp.263-273
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• 2013

A mean-value result, saying that the difference quotient of a differentiable function in a real interval is a mean value of its derivatives at the endpoints of the interval, leads to the functional equation $$\frac{f(x)-F(y)}{x-y}=M(g(x),\;G(y)),\;x{\neq}y$$, where M is a given mean and $f$, F, $g$, G are the unknown functions. Solving this equation for the arithmetic, geometric and harmonic means, we obtain, respectively, characterizations of square polynomials, homographic and square-root functions. A new criterion of the monotonicity of a real function is presented.

• Bulletin of the Korean Mathematical Society
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• v.52 no.2
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• pp.557-570
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• 2015

Let $\mathbb{G}$ be a von Neumann algebraic locally compact quantum group, in the sense of Kustermans and Vaes. In this paper, as a consequence of a notion of amenability for actions of Lau algebras, we show that $\hat{\mathbb{G}}$, the dual of $\mathbb{G}$, is co-amenable if and only if there is a state $m{\in}L^{\infty}(\hat{\mathbb{G}})^*$ which is invariant under a left module action of $L^1(\mathbb{G})$ on $L^{\infty}(\hat{\mathbb{G}})^*$. This is the quantum group version of a result by Stokke [17]. We also characterize amenable action of Lau algebras by several properties such as fixed point property. This yields in particular, a fixed point characterization of amenable groups and H-amenable representation of groups.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.11
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• pp.898-903
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• 2001

In this study, we investigated amounts, distributions and sizes of pores of multilayer piezoelectric transformer, and predicted heat emission property and electrical characteristics according to designs of internal electrode. Forming densities of device having MLC, fingered and full filled internal electrode structure were 4.73 g/㎤, 4.80 g/㎤, 4.82 g/㎤ and forming porosities were 17.3737%, 13.1475%, 12.6121%, respectively. And sintered densities of MLC structured, fingered and full filled devices were 7.76 g/㎤, 7.75 g/㎤, 7.84 g/㎤ and sintered porosities were 4.0967%, 2.7132%, 2.5317%, respectively. Therefore, we concluded that fingered and full fi1led internal electrode devices, expecially, fingered internal electrode devices had cost-effective effect and maximum poling effect due to higher sintered density and lower porosity than MLC structured device. Also we can predict that they have an effect on good heat emission and high output properties of multilayer piezoelectric transformer.

• Herbal Formula Science
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• v.15 no.1
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• pp.137-144
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• 2007

Background and Objectives : There are three kinds of formulas for purging the spleen to cure its sthenic syndrome based on the types of preparation formulas : Sabeetang, Sabeehwan, Sabeesan and Sabeeeum. Another formulas called Sahwangtang, Sahwangsan. Sahwangeum is to purge the yellow colour of spleen. There are 8 kinds of Sabeetang, 3 kinds of Sabeehwan, 3 kinds of Sabeesan, 1 kind of Sabeeeum, 4 kinds of Sahwangtang, 7 kinds of Sahwangsan, and 1 kind of Sahwangeum. Combination of herbal medicines, carried out in formulas for purging the spleen, consists of various kinds depending on medical scientists' personal experience in medical treatment without any general principles, which makes it difficult to apply it to clinical use. The objectives of this study lie in theoretical establishment of Sabeetang for curing the sthenic syndrome of spleen through analyzing the component medicines and combination principles of Hyeongok's Sabeetang, and furthermore, maximizing the clinical use of Sabeetang. Methods : This study analyzed the component medicines and combination principles of Hyeongok's Sabeetang based on the theory for properties and tastes of herbal medicines from the ${\ulcorner}$Yellow Emperor's Canon of Internal Medicine${\lrcorner}$ , the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine, and the five elements doctrine. Hyeongok's Sabeetang is an odd prescription, composed of 7 kinds of ingredients : No.1 Rhizoma Coptidis (2don;7.5g), No.2 Fructus Gardeniae (1don;3.75g), No.3 Ramulus Cinnamomi (1don), No.4 Gypsum Fibrosum (1don), No.5 Fructus Aurantii Immaturus (1don), No.6 Cortex Magnoliae Omcinalis (1don), and No.7 Radix Et Rhizoma Rhei (1don) Results : There are three methods for curing the sthenic syndrome of spleen according to the five elements doctrine : purging the spleen, purging the lung and invigorating the liver. First, if you suffer from the sthenic syndrome of the spleen, you need to purge your spleen. There are two available methods, including taste and property purgation according to the theory for properties and tastes of herbal medicines. They each imply the bitter taste and the cool property purge the spleen. In the case of taste purgation, two herbal medicines with bitter taste. Rhizoma Coptidis and Fructus Gardeniae, are combined into the principal and assistant herbal medicine, respectively. For property purgation, three herbal medicines with the cool property, Gypsum Fibrosum, Fructus Aurantii Immaturus and Radix Et Rhizoma Rhei, are combined into adjuvant herbal medicines. Secondly, if you suffer from the sthenic syndrome of the spleen, you need to purge your lung which is child in the mother-child relationship in inter-promotion among the five elements. There are two methods to purge the lung, including taste and property purgation according to the theory for properties and tastes of herbal medicines. They each mean the pungent taste and the warm property purge the lung. Therefore, it is important to use pungent herbal medicines for taste purgation and warm ones for property purgation. Both pungent and warm herb and property invigoration to invigorate the liver with warm property. Therefore, it is important to use pungent herbal medicines for taste invigoration and warm ones for property invigoration. Both pungent and warm herbal medicines, Ramulus Cinnamomi and Cortex Magnoliae Officinalis, were combined to invigorate the liver and purge the lung. In addition, Gypsum Fibrosum are combined as dispatcher herbal medicine, leading all the herbal medicines composing the formula to the spleen. Conclusions : First, to cure the sthenic syndrome of the spleen, the methods of purging the spleen and the lung, and invigorating the liver should be used according to the five elements doctrine. Secondly, herbal medicines appropriate for those treatment methods should be chosen according to the theory for properties and tastes of herbal medicine and thirdly, the combination of those herbal medicines should be carried out according to the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine. As a good example, Hyeongok's Sabeetang is combined according to the above theories. In conclusion, this formula was created by applying to the theory for properties and tastes of herbal medicines.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.3
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• pp.591-595
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• 2007

There are eight kinds of formulas for invigorating the liver to cure its asthenic syndrome based on the types of preparation formulas Began-tang, Boganhwan, Bogansan, Bogandan, Boganeum, Boganjoo, Boganjeon and Bogango. Another formula called Bocheonghwan is to invigorate the green colour of liver. There are 22 kinds of Bogan-tang, 12 kinds of Boganhwan, 25 kinds of Bogansan, one kind of Bogandan, one kind of Boganeum, one kind of Boganjoo, one kind of Boganjeon, one kind of Bogango, and two kinds of Bocheonghwan. Combination of herbal medicines, carried out in formulas for invigorating the liver, consists of various kinds depending on medical scientists' personal experience in medical treatment without any general principles, which makes it difficult to apply it to clinical use. The objectives of this study lie in theoretical establishment of Bogan-tang for curing the asthenic syndrome of liver through analyzing the component medicines and combination principles of Hyeongok's Bogan-tang, and furthermore, maximizing the clinical use of Began-tang. This study analyzed the component medicines and combination principles of Hyeongok's Bogan-tang based on the theory for properties and tastes of herbal medicines from the ${\ulcorner}$yellow Emperor's Canon of Internal Medicine${\lrcorner}$ , the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine, and the five elements doctrine. Hyeongok's Began-tang is an odd prescription, composed of 7 kinds of ingredients No.1 Radix Angelicas Sinensis (2don;7.5g), No.2 Rhizoma Chuanxiong (1don;3.75g), No.3 Radii Polygoni Multiflori (1don), No.4 Fructus Lycii (1don), No.5 Cortex Cinnamomi (1don), No.6 Rhizoma Gastrodiae (1don), and No.7 Radix Glycyrrhizae (1don). There are three methods for curing the asthenic syndrome of liver according to the five elements doctrine invigorating the liver, invigorating the kidney and purging the lung. First, if you suffer from the asthenic syndrome of the liver, you need to invigorate your liver. There are two available methods, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each imply the pungent taste and the warm property invigorate the liver. In the case of taste invigoration, two herbal medicines with pungent taste, Radix Angelicas Sinensis and Rhizoma Chuanxiong, are combined into the principal and assistant herbal medicine, respectively. For property invigoration, two herDal medicines with the warm property, Cortex Cinnamomi and Rhizoma Gastrodiae, are combined into adjuvant herbal medicines. Secondly, if you suffer from the asthenic syndrome of the liver, you need to invigorate your kidney which is mother in the mother-child relationship in inter-promotion among the five elements. There are two methods to invigorate the kidney, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each mean the bitter taste and the cold property invigorate the kidney. Therefore, it is important to use bitter herbal medicines for taste invigoration and cold ones for property invigoration. Both Differ and cold herbal medicines, Radix Polygoni Multiflori and Fructus Lycii, are combined into adjuvant herbal medicines. Lastly, if you suffer from the asthenic syndrome of the liver, you need to purge your lung which is an element being surpassed in the relationship between the elements surpassed and ones not surpassed in inter-restraint among the five elements. There are two methods to purge the lung, which include taste and property invigoration according to the theory for properties and tastes of herbal medicines. Taste invigoration means to purge the lung with pungent taste and property invigoration to purge the lung with warm property. Therefore, it is important to use pungent herbal medicines for taste invigoration and warm ones for property invigoration. Both pungent and warm herbal medicines, Radix Angelicas Sinensis and Rhizoma Chuanxiong, were combined to invigorate and purge the lung. In addition, Radix Glycyrrhizae are combined as dispatcher herbal medicine, harmonizing all the herbal medicines composing the formula. First, to cure the asthenic syndrome of the liver, the methods of invigorating the liver and the kidney, and purging the lung should be used according to the five elements doctrine. Secondly, herbal medicines appropriate for those treatment methods should be chosen according to the theory for properties and tastes of herDal medicine and thirdly, the combination of those herbal medicines should be carried out according to the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine. As a good example, Hyeongok's Bogan-tangon is combined according to the above theories. In conclusion, this formula was created by applying to the theory for properties and tastes of herbal medicines.

• Journal of the Korean Electrochemical Society
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• v.19 no.4
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• pp.129-133
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• 2016

In this study, a polymer-carbon composite material is prepared for environmental-friendly organic anode. On poly(styrenesulfonate)(PSS)-carbon composite anode, the carbon is coated by PSS as a core-shell structure and the PSS-carbon composite anode has $524mAh\;g^{-1}$ theoretical capacity with <0.6V voltage. Moreover, the PSS-carbon composite anode shows $519.6mAh\;g^{-1}$, $461.2mAh\;g^{-1}$, $411.8mAh\;g^{-1}$ and $315.9mAh\;g^{-1}$ discharge capacities at 0.1, 0.5, 1 and 10 C, respectively, and stable cycle performance up to 30 cycles. The PSS-carbon composite anode, containing polystyrene and sulfonate functional groups, is suitable for high electrochemical properties organic rechargeable battery.

• Journal of Practical Agriculture & Fisheries Research
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• v.7 no.1
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• pp.55-63
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• 2005

Tuber yield and content of general component and diosgenin which is a main bioactive property were investigated in order to determine the growth characteristics of round typed yam(Dungeun-ma, Dioscorea opposita L.) and the potential of artificial culture at Suwon, Korea. Sprouting rates of segmented small tubers such as 3, 5, 7, 9, and 12g were respectively 60.3, 80.5, 85.3, 98.6 and 99.3% when they were investigated 30 days after planting. Segmented small tubers of 3, 5, 7, 9, and 12g enlarged respectively to 66, 87, 98, 120, and 140g in the green-house cultivation. Segmented small tubers of 3, 7, 12, 18, and 23g enlarged respectively to 35.2, 124.7, 142.7, 174.8, and 200,7g in the open-air field cultivation.

• Bulletin of the Korean Mathematical Society
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• v.26 no.2
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• pp.109-114
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• 1989

This paper deals with the classifying spaces of finite groups. To any finite group G we associate a space BG with the property that .pi.$_{1}$(BG)=G, .pi.$_{i}$ (BG)=0 for i>1. BG is called the classifying space of G. Consider the problem of finding a stable splitting BG= $X_{1}$$^{V}$ $X_{1}$$^{V}$..$^{V}$ $X_{n}$ localized at pp. Ideally the $X_{i}$ 's are indecomposable, thus displaying the homotopy type of BG in the simplest terms. Such a decomposition naturally splits $H^{*}$(BG). The main purpose of this paper is to give the classification theorem in stable homotopy theory for groups with periodic cohomology i.e. cyclic Sylow p-subgroups for p an odd prime and to calculate some universal stable element. In this paper, all cohomology groups are with Z/p-coefficients and p is an odd prime.prime.

• Journal of applied mathematics & informatics
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• v.6 no.1
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• pp.309-320
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• 1999

Models of single-server queues with vacations have been widely used to study the performance of many computer communi-cation and production systems. In this paper we analyze an M/G/1 queue with generalized vacations and exhaustive service. This sys-tem has been shown to possess a stochastic decomposition property. That is the customer waiting time in this system is distributed as the sum of the waiting time in a regular M/G/1 queue with no va-cations and the additional delay due to vacations. Herein a general formula for the additional delay is derived for a wide class of vacation policies. The formula is also extended to cases with multiple types of vacations. Using these new formulas existing results for certain vacation models are easily re-derived and unified.