• Bulletin of the Korean Chemical Society
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• 제10권1호
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• pp.39-51
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• 1989

The infrared and resonance Raman spectra are reported for nickel and zinc tetraphenylchlorins. It is found that the IR and RR spectra become more complicated compared with the corresponding porphyrin analogs due to the symmetry changes. Some vibrational parameters like the core size and the symmetry change are examined in accordance with vibrational spectra of other type of chlorins.

• Bulletin of the Korean Chemical Society
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• 제11권4호
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• pp.313-317
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• 1990

Geometries for several representative quinolone carboxylate type antibacterials have been calculated by computer graphics/molecular mechanics energy minimization procedures using both MM2 and AMBER force fields. The calculated geometries were found to be in reasonable agreements with the corresponding X-ray crystal structures. It has been pointed out that notwithstanding the weaknesses associated with calculating the resonance and hydrogen bonding contributions, the employed methods are capable of generating credible ring geometries and torsional angle dispositions of N(1)-ethyl and 3-carboxylate substituents of the quinolones.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.409.1-409.1
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• 2002

For the development of a biocompatible nano-scale drug carrier. hydrophilic polysaccharide pullulan was hydrophobized by the conjugation with fatty acid. The synthesized polymers were characterized by the measurements of fourier transform infrared (FT -IR) spectroscopy and 1H -nuclear magnetic resonance (NMR) spectroscopy. In aqueous solution. hydrophobically modified puliulan was self-assembled and structured into the core-shell type nanoparticles. (omitted)

• Investigative Magnetic Resonance Imaging
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• 제17권1호
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• pp.8-18
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• 2013

목적: 척추전이의 자기공명영상 소견들 중 특정 원발성 암에 특이적인 소견들이 있는지 알아보고자 한다. 대상과 방법: 본 연구에서는 자기공명영상을 시행한 총 169개의 척추전이암 병변들 (56개는 폐암, 29개는 유방암, 20개는 대장암, 17개는 간세포암, 그리고 47개는 위암으로부터 기원)을 후향적으로 분석하였다. 각 병변의 크기, 위치, 침범 정도, 신호강도, 경계, 조영증강 양상, 그리고 골융해/골경화 특성들을 분석하여 원발성 암의 기원에 따라 차이가 있는지 보았다. 결과: 간세포암의 전이 병변들은 대장암을 제외하고는 (P=0.268) 다른 암에 비하여 크기가 유의하게 컸다 (P < 0.05). 경계가 좋은 병변은 폐암과 유방암에서 기원한 경우에서 더 흔히 관찰되었다 (P < 0.01). 간세포암을 제외한 모든 암에서 전이를 할 때 척추의 후부요소보다 척추체를 더 자주 침범하였다(P < 0.02). 대장암과 간세포암은 골외 침범을 더 자주 보였으나 통계학적 의미는 없었다 (P > 0.05). 간세포암과 위암의 전이병변들은 특징적인 조영증강 양상을 보였다. 결론: 일부 자기공명영상 소견들은 척추전이 병변이 어떤 원발성 암에서 기원한 것이지 예측하는 데 도움이 될 수 있다.

• 한국전기전자재료학회논문지
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• 제19권7호
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• pp.644-649
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• 2006

This paper presents a new disk-type piezoelectric transformer. The input side of the transformer has a crescent-shaped electrode and the output side has a focused poling direction. The piezoelectric transformers operated in each transformer's resonance vibration mode. The electrodes and poling directions on commercially available piezoelectric ceramic disks were designed so that the planar or shear mode coupling factor $(k_p\;k_{15})$ becomes effective rather than the transverse mode coupling factor $(k_{31})$. ANSYS finite element code was used to analyze transformer behavior and to optimize electrode and poling configurations. The voltage step-up ratio of the proposed transformer has been markedly improved in comparison with that of the equivalent rectangular(Rosen) type. A single layer prototype transformer, $20\sim30mm$ in diameter and $1.0\sim3.5mm$ thick, was fabricated, such as step-up ratio, power transformation efficiency, and temperature were measured. While the transformer was driving a Cold Cathode Fluorescent Lamp(CCFL), the temperature field of the transformer was also observed.

• 복식
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• 제52권6호
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• pp.41-50
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• 2002

The purpose of this study is to classify korean clothing image using brainstorming method. Brainstorming theme is selected 'The Land of Morning Calm 'which famed to foreigner about Korea. Brainstorming members were 10 persons for 1st. 9 persons for End. The 119 words of association from 'morning calm'were to extracted at 1st brainstorming. The group of senses image were to classified at End brainstorming. The results of this study were as follows : 1. The clothing image type of tactual sense implied feeling of that downy bedding in a soft spring and grandmother's hands as warm. rough. 2. The clothing image type of smelling sense associated smells of pleasant. mild. and fresh. 3. The clothing image type of auditive sense consisted mainly sense of indirect. resonance. small, and clear sounds. 4. The clothing image type of visual sense associated pure, passive, gentle, and lasting life-force as weeds and wild flowers. Korean line is pointless and rounded curve. Korean form is soft silhouette as streamy, not exaggerate and wavy detail of slim and short. Korean color is not dyed, just natural color and pastel tone. Korean textile is a natural material as linen, ramie. and coarse silk.

• 한국정밀공학회지
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• 제21권2호
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• pp.203-209
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• 2004

Compliant bi-stable mechanism allows two stable states within its operation range staying at one of the local minimum states of the potential energy. Energy storage characteristics of the bi-stable mechanism offer two distinct and repeatable stable states, which require no power input to maintain it at each stable state. This paper suggests an equivalent model of the chevron-type bi-stable microactuator using the equivalent spring stiffness in the rectilinear and the rotational directions. From this model the range of spring stiffness where the bi-stable mechanism can be operated is analyzed and compared with the results of the FEA (Finite Element Analysis) using ANSYS for the buckling analysis, both of which show a good agreement. Based on the analysis, a newly designed chevron-type bi-stable MEMS actuator using hinges is suggested for the latch-up operation. It is found that the experimental response characteristics of around 36V for the bi-stable actuation for the 60$mu extrm{m}$ stroke correspond very well to the results of the equivalent model analysis after the change in cross-sectional area by the fabrication process is taken into account. Together with the resonance frequency experiment where 1760Hz is measured, it is shown that the chevron-type bi-stable MEMS actuator using hinges is applicable to the optical switch as an actuator.

• 한국전자파학회논문지
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• 제15권5호
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• pp.467-472
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• 2004

본 논문은 80 ㎒ 이하의 주파수 대역에서 사용하는 강제 공진형 EMI 다이폴 안테나에 대한 정규화 시험장 감쇠량 이론곡선을 계산하고 있다. 이론 해석으로서는 안테나에 흐르는 전류분포에 관한 연립적분방정식을 유도하고 구분 정현함수를 사용한 Galerkin의 모멘트 법으로 그 해를 구하여 정규화 시험장 감쇠량을 검토하고 있다. 그 결과, 강제 공진형 EMI 다이폴 안테나는 80 ㎒ 이하 주파수 대역의 정규화 시험장 감쇠량 측정에 유용하게 사용할 수 있음을 확인할 수 있었다. 제시된 정규화 시험장 감쇠량 이론치는 강제 공진형 EMI 다이폴 안테나를 사용하여 야외시험장의 적합성을 평가할 때 기준이론 곡선으로 활용할 수 있다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.780-785
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• 2003

Recently the trends in information storage devices need small size, mobility, high capacity, and low power consumption etc. To satisfy those, the development of high performance actuator is an important issue. Compared with general linear actuator for optical disk drive, swingarm type rotary actuator is suitable to design in small form factor and has fast access time for random access. Swingarm actuator is designed considering the structural problem and the actuating force of VCM(Voice Coil Motor). The increase of mass caused by optical components makes vibration problems of swing-arm, therefore resonance frequency should be increased and inertia has to be reduced. ANSYS FEM tool is employed in optimizing swingarm. The VCM is designed using 3-D electro-magnetic analysis, and parameters of magnetic circuit are determined to matte large flux density. The large flux density enables to achieve low power consumption. VCM holder is designed to get the mass balance of total actuator and this balance reduces the magnitude of critical mode relative to pivot bearing, It is expected that swingarm type rotary actuator designed by this method is available to variable type of micro optical disk drives.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.303-312
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• 2003

This paper suggests a fuzzy expert system for fault diagnosis of rotating machinery, based on modulated databases. In the proposed system, alarm and trip levels are set based on ISO, considering operating condition, machinery type and maintenance history. Input signals for diagnosis, such as sub- and super-harmonic components of vibration and mean value, are normalized from 0 to 1 under the threshold level and otherwise equal to one so that chronic faults slightly below the threshold level can be monitored. The database for diagnosis consists of two modules: the well-known Sohre's chart module and if-then type rules. The Sohre's chart is utilized for the most common problems of high-speed turbomachinery, while the rule-based module, which was collected from many papers and reports, is for diagnosing peculiar faults according to the type of machinery. To infer the results from two modules, a fuzzy operation of Yager sum was adopted. Using a simulator constructed in laboratory, experimental verification was performed for the cases of resonance and housing looseness which were intended. The experimental results show that the proposed fuzzy expert system has feasibility in practical diagnosis of rotating machinery.