• Journal of the Korea Furniture Society
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• v.19 no.1
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• pp.22-32
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• 2008

Revolution of software and hardware technology changed TV from cathode-ray tube to a LCD or PDP. And this change calls for change of TV decoration cabinet. The flat panel TV stands market is very a world-wide enormous size with the function which is various and breed and design is forming. Nonetheless, Our flat panel TV stands production method and technique is to a phase which imitates the product of the foreign nation which precedes. Currently our country TV / AV decoration cabinet is staying to only the acceptance function which is simple. Consequently, the development of the new flat panel TV stands that matches in the house culture which is modernized with applies the visual effect which is various, effective design and function is necessary. The fact that it develops the product which equips the function characteristic which is new and convenient is objective of sample planning.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.118-121
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• 1991

The characteristics of magnetizing system considering the anisotropy and the nonlinearity are analyrized using PEM in This paper. The case of magnetizing the ferrite magnet with 12 poles is analyrized. The anisotropy characteristic is considered when ferrite magnet which is widely used as permanent magnet is magnetized. The Nonlinear characteristic of magnetizing yoke aid ferrite is considered because the current is in the saturation region. When the magnetizing current value is over the optimum value, the magnet is magnetized with 24 poles. This is not the case of our expectation. Thus, for the case of our expected magnetizing form, it is the conclusion that the optimum magnetizing current value is selected.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1219-1224
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• 2001

In this study, concrete what plenty of fly ash used as binder is left in three condition humid condition($35^{\circ}C$), normal condition($20^{\circ}C$) and cold condition($5^{\circ}C$). Fly ash concrete is tested in fresh properties and early strength. The result of tests could give the decisive factor of form side's stripping time. The purpose of this study is presenting the stripping time data to help the construction work. The result of this study is below. 1. The plain concrete specimen in humid condition developed high strength before 5 days, then strength development is declined. 10 day strength of plain specimen is smaller than the normal condition specimen's. 2. The strength of the concrete which plenty of fly ash used is more developed than the concrete in normal condition. It says that fly ash concrete is useful in the humid condition. 3. As fly ash substitution rate is downsizing and outdoor temperature degree is low, form stripping times is getting shorter.

• Journal of Environmental Science International
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• v.7 no.6
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• pp.875-881
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• 1998

Microemulsion is prepared by the method of phase inversion emulsification with d-limonene that is environmental friendly substance and nontoxic to human body as dispersed phase. Emulsifier used for preparation of microemulsion is nonionic surfactants, polyoxyethylene nonylphenyl ether. Stability of prepared microemulsion was estimated by the various method of ξ-potential, hydrodynamic diameter and electric conductivity. When d-limonene is emulsified by NP series, microemulsion is most stable and narrowly distributed at HLB value of 12.3(either one emulsifier or mixed emulsifiers). Stability of microemulsion is increased as the amount of emulsifiers is increased at same HLB value of 12.3. In the case of using the same amount of emulsifiers, number of produced micelle are relatively large as hydrodynamic diameter is small. Therefore, the state of microemulsion is stable and the electric conductivity is increased. One can determine that higher electric conductivity value means that microemulsion has more micelles and is more stable.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.620-623
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• 2000

A very simple control approach using neural network for the robust position control of a Permanent Magnet Synchronous Motor(PMSM) is presented The linear quadratic controller plus feedforward neural network is employed to obtain the robust PMSM system approximately linearized using field-orientation method for an AC servo. The neural network is trained in on-line phases and this neural network is composed by a fedforward recall and error back-propagation training. Since the total number of nodes are only eight this system can be easily realized by the general microprocessor. During the normal operation the input-output response is sampled and the weighting value is trained multi-times by error back-propagation method at each sample period to accommodate the possible variations in the parameters or load torque. And the state space analysis is performed to obtain the state feedback gains systematically. IN addition the robustness is also obtained without affecting overall system response. This method is realized by a floating-point Digital Singal Processor DS1102 Board (TMS320C31) The basic DSP software is used to write C program which is compiled by using ANSI-C style function prototypes.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1175_1176
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• 2009

In comparison with different mass transportation systems, the streetcar is lower, both in speed and transportation capacity. However, it has the advantage of reducing the cost of construction, because it makes infrastructure simple, by using the road. It is proper in the city, where the population is few, to raise the efficiency of traffic. The convenience is high to passengers. On time accuracy and the commercial speed is influenced by operating condition. Generally that is organized into 21m degree in 6 quantity. All passengers in a streetcar are about 180 people. The maximum speed is 40~60km/h. When road traffic is considered, the speed can be reduced to 15km/h. To enhance the speed, the construction of a priority signaling system is necessary which is integrated with the road traffic operation information system. In order to develop a better Traffic Control System which is connected to a Traffic Control Center, a Priority Signaling System which incorporates Intersection Control Technics must be included.

• Korean Institute of Interior Design Journal
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• no.20
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• pp.91-97
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• 1999

Telecommuting becomes a new form of work according to the development of information technology. Therefore, the purpose of this study is to provide basic data for the interior space planning of telecommuting centers by means of surveying office workers' opinions. The major findings of this research are as follows. The opinion about whether to use telecommuting center if provided is showed highly positively. In the matter of space type of telecommuting center, 'mixing type I (open plan office but division with high partition)' is the most preferred, the next, is 'closed type'. The most preferred type of workstation is 'independent type', the next is 'X type' and the third is 'link type'. Preferred partition height is '1,300-1,500mm'. When planning telecommuting center, the most important element of space plan is 'size and layout of workstation' and the second is 'private space for confidential work'. In public workplace, the most important element 'refreshment space', and the second one is 'mailing system'.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.2
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• pp.303-311
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• 1996

The Self Healing Ring (SHR) is one of the most Intriguing schemes which provide survivability for telecommunication networks. To design a cost effective SONET ring it is necessary to consider load balancing problems by which the link capacity is determined. The load balancing problem in SONET ring when demand splitting is not allowed is considered in this paper. An efficient algorithm is presented which provides the best solution starting from various Initial solutions. The initial solution is obtained by routing ell demands such that no demands pass through an are In the ring. The proposed algorithm iteratively improves the Initial solution by examining each demand and selecting the maximum load are in its path. The demand whose maximum arc load is biggest is selected to be routed in opposite direction. Computational results show that the proposed algorithm is excellent both in the solution quality and in the computational time requirement. The average error bound of the algorithm is 0.11% of the optimum and compared to dual-ascent approach which has good computational results than other heuristics.

• Bulletin of the Korean Mathematical Society
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• v.42 no.4
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• pp.807-815
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• 2005

Let R be a ring with identity, X the set of all nonzero, nonunits of Rand G the group of all units of R. We will consider two group actions on X by G, the regular action and the conjugate action. In this paper, by investigating two group actions we can have some results as follows: First, if G is a finitely generated abelian group, then the orbit O(x) under the regular action on X by G is finite for all nilpotents x $\in$ X. Secondly, if F is a field in which 2 is a unit and F $\backslash\;\{0\}$ is a finitley generated abelian group, then F is finite. Finally, if G in a unit-regular ring R is a torsion group and 2 is a unit in R, then the conjugate action on X by G is trivial if and only if G is abelian if and only if R is commutative.

• Bulletin of the Korean Mathematical Society
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• v.43 no.2
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• pp.299-307
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• 2006

The following results ale extended from P-injective rings to AP-injective rings: (1) R is left self-injective regular if and only if R is a right (resp. left) AP-injective ring such that for every finitely generated left R-module M, $_R(M/Z(M))$ is projective, where Z(M) is the left singular submodule of $_{R}M$; (2) if R is a left nonsingular left AP-injective ring such that every maximal left ideal of R is either injective or a two-sided ideal of R, then R is either left self-injective regular or strongly regular. In addition, we answer a question of Roger Yue Chi Ming [13] in the positive. Let R be a ring whose every simple singular left R-module is Y J-injective. If R is a right MI-ring whose every essential right ideal is an essential left ideal, then R is a left and right self-injective regular, left and right V-ring of bounded index.