• 대한화학회지
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• 제24권2호
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• pp.91-100
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• 1980

축방향대칭을 갖는 팔면체 $[Ti(III)A_3B_3]$형태 착물의 자기모멘트를 계산하는 식을 유도하여 distortion parameter$({\delta})$, 스핀-궤도 상호작용상수$({\zeta}')$ 및 orbital reduction factor의 실험치를 사용하여 이들 착물의 자기모멘트를 계산하였다. 축방향으로 일그러진 팔면체 $[Ti(III)A_3B_3]$형태 착물의 계산한 자기모멘트가 실험치와 비교적 일치하였다. 팔면체로부터 축방향 일그러짐이 커짐에 따라 그리고 orbital reduction factor가 감소함에 따라 계산한 자기모멘트의 값이 크게 감소하였다. 축방향대칭보다 낮은 리간드장으로 일그러진 팔면체착물의 자기모멘트를 계산하는 방법을 발전시켰으며 계산한 자기모멘트를 기초로 하여 일그러진 팔면체 $[Ti(III)A_3B_3]$형태 착물의 구조를 논의하였다.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2011년도 자성 및 자성재료 국제학술대회
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• pp.14-14
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• 2011

Limited understanding of the surface properties of $Pt_3Ni$ for the oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cell (PEMFC) has motivated the study of magnetic properties and electronic structures of Pt segregated $Pt_3Ni$ (111) surface during adsorption of oxygen molecule on it. The first principle method based on density functional theory (DFT) is carried out. Nonmagnetic Pt has induced magnetic moment due to strong hybridization between Ni 3d and Pt 5d. It is found that an oxygen molecule prefers bridge site with Pt rich subsurface environment for adsorption on the surface of Pt segregated $Pt_3Ni$ (111). It is seen that there is very small charge transfer from $O_2$ to Pt. The curve of energy versus magnetic moment of the oxygen explains the magnetic moments in transition states. We found the dissociation barrier of 1.07eV significantly higher than dissociation barrier 0.77eV on Pt (111) suggesting that the dissociation is more difficult on Pt segregated $Pt_3Ni$ (111) surface. The spin polarized densities of states are presented in order to understand electronic structures of Pt and $O_2$ during the adsorption in detail.

• 한국전기전자재료학회논문지
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• 제12권1호
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• pp.62-68
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• 1999

Ferroelectric $Sr_{0.7}/B_{2.3}(Ta_{1-x}Nb_x)_2O_9$(x=0, 0.1, 0.2, 0.3) thin films were deposited on $Pt/SiO_2/Si$ substrate by MOD(Metalorganic Decomposition) process. Metal carboxylate and metal alkoxide were used as precursors, and 2-methoxyethanol, xylene as solvents. After spin coating, thin films were pre-annealed at $400^{\circ}C$, followed by RTA(Rapid Thermal Annealing) and final annealing at $800^{\circ}C$ in oxygen atmosphere. These procedures were repeated three times to obtain thin films with the thickness of $2000{\AA}$. To enhance the nucleation and growth of layered-perovskite phase, thin films were rapid-thermally annealed above $720^{\circ}C$ in oxygen atmosphere. As RTA temperature increased, fluorite phase was transformed to layered-perovskite phase. And the change of Nb contents affected dielectric / electrical properties and microstructure. The ferroelectric characteristics of $Sr_{0.7}/B_{2.3}(Ta_{1-x}Nb_x)_2O_9$ thin film were Pr=8.67 $\mu{C}/cm^2$, Ec=62.4kV/cm and $I_{L}=1.4\times10^{-7}A/cm^2$ at the applied voltage of 5V, respectively.

• 한방재활의학과학회지
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• 제20권3호
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• pp.37-60
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• 2010

Objectives : The purpose of this study was to investigate the relationship between masseter and cervical muscle activity and temporomandibular disorder in female office workers. Methods : Experimental group of 24 healthy subjects complained of temporomandibular joint related to computer use which lasted more than 3 months in the past year and was present in the past 7 days as well as on the day of test. Control group of 20 healthy subjects had no complaints of minimal discomfort on the day of test, and had no discomfort in the past 7 days. If they had reported discomfort in the past 12 months, it was of a short duration(<3 months) and resolved at least 3 months prior to participation. Outcomes were assessed by meridian-electromyography(MEMG), whole spin x-ray, mandibular function impairment questionnaire(MFIQ), neck disability index(NDI), visual analog scale(VAS), Beck depression inventory(BDI), stress reaction inventory(SRI) and Holmes & Rahe social readjustment rating scale(SRRS). Results : The contraction power of masseter muscle, upper trapezius, sternocleido-mastoid muscle and erector spinae by MEMG was significantly higher in the experimental group. The muscle fatigue of masseter muscle and sternodeido-mastoid muscle by MEMG was significantly higher in the experimental group. SRI was significantly higher in experimental group. There was no significant difference between two groups in the Jackson's angle, Cobb's method and cranio-cervical posture. Conclusions : The results suggest that temporomandibular disorder related mental stress but physical stress does not change cervical structure significantly.

• 전기학회논문지
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• 제63권5호
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• pp.676-682
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• 2014

In this paper, precipitation echo(PRE) and non-precipitaion echo(N-PRE)(including ground echo and clear echo) through weather radar data are identified with the aid of neuro-fuzzy algorithm. The accuracy of the radar information is lowered because meteorological radar data is mixed with the PRE and N-PRE. So this problem is resolved by using RBFNN and judgement module. Structure expression of weather radar data are analyzed in order to classify PRE and N-PRE. Input variables such as Standard deviation of reflectivity(SDZ), Vertical gradient of reflectivity(VGZ), Spin change(SPN), Frequency(FR), cumulation reflectivity during 1 hour(1hDZ), and cumulation reflectivity during 2 hour(2hDZ) are made by using weather radar data and then each characteristic of input variable is analyzed. Input data is built up from the selected input variables among these input variables, which have a critical effect on the classification between PRE and N-PRE. Echo judgment module is developed to do echo classification between PRE and N-PRE by using testing dataset. Polynomial-based radial basis function neural networks(RBFNNs) are used as neuro-fuzzy algorithm, and the proposed neuro-fuzzy echo pattern classifier is designed by combining RBFNN with echo judgement module. Finally, the results of the proposed classifier are compared with both CZ and DZ, as well as QC data, and analyzed from the view point of output performance.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.167-170
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• 2001

The stochiometric mix of evaporating materials for the CdGa$_2$Se$_4$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, CdGa$_2$Se$_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were 630$^{\circ}C$ and 420$^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of CdGa$_2$Se$_4$ single crystal thin films measured from Hall erect by van der Pauw method are 8.27x10$\^$17/ cm$\^$-3/, 345 $\textrm{cm}^2$/V$.$s at 293 K, respectively. From the Photocurrent spectrum by illumination of perpendicular light on the c-axis of the CuInSe$_2$ single crystal thin film, we have found that the values of spin orbit splitting ΔSo and the crystal field splitting ΔCr were 106.5 meV and 418.9 meV at 10 K, respectively. From the photoluminescence measurement on CdGa$_2$Se$_4$ single crystal thin film, we observed free excition (E$\_$X/) existing only high quality crystal and neutral bound exiciton (D$\^$0/,X) having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy of neutral donor bound excision were 8 meV and 13.7 meV, respectivity. By Haynes rule, an activation energy of impurity was 137 meV,

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.163-166
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• 2001

The stochiometric mix of evaporating materials for the ZnGa$_2$Se$_4$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, ZnGa$_2$Se$_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were 61$0^{\circ}C$ and 45$0^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of ZnGa$_2$Se$_4$ single crystal thin films measured from Hall effect by van der Pauw method are 9.63x10$^{17}$ cm$^{-3}$ , 296 $\textrm{cm}^2$/V.s at 293 K, respectively, From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the ZnGa$_2$Se$_4$ single crystal thin film, we have found that the values of spin orbit splitting $\Delta$So and the crystal field splitting $\Delta$Cr were 251.9 MeV and 183.2 meV at 10 K, respectively. From the photoluminescence measurement on ZnGa$_2$Se$_4$ single crystal thin film, we observed free excition (E$_{x}$) existing only high quality crystal and neutral bound excition (A$^{0}$ ,X) having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy of neutral acceptor bound excition were 11 meV and 24.4 meV, respectivity. By Haynes rule, an activation energy of impurity was 122 meV.on energy of impurity was 122 meV.

• 한국산학기술학회논문지
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• 제11권3호
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• pp.821-826
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• 2010

도어락 스위치(Door-lock switch)는 드럼세탁기, 식기 세척기 등 회전이나 열이 발생되어 작동 할 때 임의로 열지 못하도록 하는 가전제품에 쓰이는 도어 안전잠금장치로 드럼세탁기에서는 없어서는 안 되는 중요한 부품 중의 하나이다. 드럼 세탁기 도어는 소비자가 사용 할 때 느낌을 가지는 부분으로 항상 안전성과 동시에 감성이 뒤따르는 부품이기도 하다. 본 논문은 드럼세탁기의 도어에 감성과 관련된 요소들을 조사하였으며, 도어락 스위치의 기구적인 구조들을 파악한 뒤 드럼세탁기에 장착하였을 때 열림력, 닫힘력을 측정할 수 있는 지그와 소프트웨어를 제작하고 측정한 힘의 그래프를 분석하여 사용자에 의해 평가한 후, 드럼세탁기 도어락 스위치의 구조에 따른 감성에 차이점을 찾아보고 시스템의 사용을 검증하였다.

• 한국IT서비스학회지
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• 제11권4호
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• pp.251-262
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• 2012

Unit testing is one of the test levels, which tests an individual unit or a group of related units. Recently, in Agile Development or Safety-critical System Development, the unit testing plays an important role for the qualities. According to the definition of unit testing, it is supposed to be done by the developers of units. That is because test models for the unit testing refers to the structure of units, and others but its original developers hardly can understand the structures. However, in practice, unit testing is often asked to be done without the original developers. For example, it is when faults are revealed in customer sites and the development team does not exit any more. In this case, instead of original developers, other developers or test engineers take a product and test it. The unit testing done by a non-developer, who is not the original developer, would cause some difficulties or cause more cost. In this paper, we tests an open source, JTopas, as a non-developer, with building test models, implementing test codes, and executing test cases. To fit this experiment to practical testing situations, we designed it based on the practices of unit testing, which were surveyed through SPIN(Software Process Improvement Network). This paper analyzes which part of unit testing done by non-developers needs more effort compared to the unit testing done by original developers. And it concludes that Agile Development contributes on reducing the extra effort caused by non-developers, since it implements test codes first before developing source code. That means all the units have already included their own tests code when they are released.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.179-180
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• 2007

Single crystal $AgGaSe_2$ layers were grown on thoroughly etched semi-insulating GaAs(100) substrate at $420^{\circ}C$ with hot wall epitaxy (HWE) system by evaporating $AgGaSe_2$ source at $630^{\circ}C$. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of single crystal $AgGaSe_2$ thin films measured with Hall effect by van der Pauw method are $4.05{\times}\;10^{16}/cm^3$, $139\;cm^2/V{\cdot}s$ at 293 K. respectively. The temperature dependence of the energy band gap of the $AgGaSe_2$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=1.9501\;eV\;-\;(8.79{\times}10^{-4}\;eV/K)T^2$/(T + 250 K). The crystal field and the spin-orbit splitting energies for the valence band of the $AgGaSe_2$ have been estimated to be 0.3132 eV and 0.3725 eV at 10 K, respectively, by means of the phcitocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}So$ definitely exists in the $\Gamma_5$ states of the valence band of the $AgGaSe_2$. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-, and $C_1$-exciton peaks for n = 1.