• Fibers and Polymers
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• 제3권2호
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• pp.60-67
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• 2002

In the present study, the fluorescence behavior ova phenylethynyl-terminated imide (LaRC PETI-5) resin, a bismaleimide (BMI) resin, and various LaRC PETI-5/BMI blends with different blend compositions has been characterized as a function of heat-treatment temperature, using a steady-state fluorescence technique with a front-face illumination method far solid-state films. It is observed that there are distinguishable changes in the spectral shape, size, and position of fluorescence with varying heat-treatment temperature in the pure and blend samples. The result is qualitatively explained in terms of charge transfer complex formation as well as microenvironmental change with local mobility and viscosity occurring in the LaRC PETI-5, BMI, and their blends during the cure process. The result also implies that a steady-state fluorescence technique may be a useful tool to understand the processing conditions of polyimides and their blends in the film form on the basis of their thermo-photophysical responses.

• The Korean Journal of Pain
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• 제8권2호
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• pp.363-366
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• 1995

Blockade of the ganglion impar was performed as an alternertive means of managing intractable neoplastic perineal pain of sympathetic origin. We successively treated a patient who had suffered from excessive perianal sweating with ganglion impar block using pure alcohol. Eight months after block, the patient has no complaint of perianal sweating. Ganglion impar block is an effective method in the treatment of excessive perianal sweating as well as perineal pain of sympathetic origin.

• 한국미생물·생명공학회지
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• 제23권4호
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• pp.411-415
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• 1995

The dextranase (EC 3.2.1.11) produced by Aspergillus ustus GR-98 was purified by the following sequential methods; salting-out and dialysis, gel filtration on BIO-GEL P-100, ion exchange chromatography on DEAH-cellulose, affinity chromatography on hydroxyapatite, and preparative electrophoresis. Three active fractions, dextranases 1, 11 and 111, were isolated in electrophoretically pure states, and specific activities of the dextranases were 1,276, 1,154 and 1,125 units/mg, the degrees of yield were 9.0, 3.6 and 2.2%, having 145, 131.1 and 127.8 times as those of culture filtrate in degree of purification, respectively. The enzyme purity was confirmed by the PAGE, SDS-PAGE and get permeation-HPLC.

• ETRI Journal
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• 제34권2호
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• pp.159-167
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• 2012

In this paper, a new distributed resource allocation algorithm is proposed to alleviate the cross-tier interference for orthogonal frequency division multiplexing access macrocell and femtocell overlay. Specifically, the resource allocation problem is modeled as a non-cooperative game. Based on game theory, we propose an iterative algorithm between subchannel and power allocation called distributed resource allocation which requires no coordination among the two-hierarchy networks. Finally, a macrocell link quality protection process is proposed to guarantee the macrocell UE's quality of service to avoid severe cross-tier interference from femtocells. Simulation results show that the proposed algorithm can achieve remarkable performance gains as compared to the pure waterfilling algorithm.

• 한국해양공학회지
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• 제13권2호통권32호
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• pp.1-10
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• 1999

This study is concerned with the application of new criterion for membrane/shell mixed element in the rigid-plastic finite element analysis and elastic-plastic finite element analysis. The membrane/shell mixed element can be selctively adapted to the pure stretching condition by using membrane or a shell element in the bending effect areas. Thus, membrane/shell mixed element requires a efficient criterion for a distinction between membrane and shell element. In the present study introduce the criterion using the angle of between two element and confirm a generality of criterion from appling the theory to a rigid-plastic and elastic-plastic problems.

• Korean Chemical Engineering Research
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• 제44권2호
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• pp.129-135
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• 2006

본 연구에서는 용매로써 sulfolane을 사용하고 2기의 증류탑을 이용하여 톨루엔이 과량 함유된 비 방향족 혼합물로부터 고 순도의 톨루엔을 생산해 내는 추출증류공정에 대한 전산모사 작업을 수행하였다. Sulfolane 용매를 이용한 추출증류공정의 모사를 위한 열역학 모델식으로는 NRTL 액체 활동도계수 모델식을 사용하였으며 범용성 화학공정 모사기인 Aspen Plus 12.1을 사용하였다. 모사 결과 최종제품으로 얻어진 톨루엔의 순도는 99.8 wt％였으며, 원료에 대한 회수율은 99.65％로 나타남을 알 수 있었다.

• 생물정신의학
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• 제17권4호
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• pp.194-202
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• 2010

Alzheimer's disease(AD) is the most common neurodegenerative disorder and constitutes about two thirds of dementia. Despite a lot of effort to find drugs for AD worldwide, an efficient medicine that can cure AD has not come yet, which is due to the complicated pathogenic pathways and progressively degenerative properties of AD. In its early clinical phase, it is important to find the subtle alterations in synapses responsible for memory because symptoms of AD patients characteristically start with pure impairment of memory. Attempts to find the target synaptic proteins and their pathogenic pathways will be the most powerful alternative strategy for developing AD medicine. Here we review recent progress in deciphering the role of target synaptic proteins related to AD in hippocampal glutamatergic synapses.

• Bulletin of the Korean Chemical Society
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• 제28권11호
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• pp.2029-2033
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• 2007

Hydrotalcite, layered double hydroxides (LDH), with hexagonal morphology has been rapidly synthesized by microwave reaction within 1 hour by urea hydrolysis from homogeneous solution. Different synthesis parameters, Mg/Al molar ratio, microwave reaction temperature and microwave power were systematically investigated. Pure hydrotalcite phase was obtained for Mg/Al ratios of 2:1 and 3:1, and higher reaction temperature gave higher crystallinity. The hydrotalcite synthesized at 600W power shows the highest crystallinity and more homogeneous crystal size distribution. The hydrotalcite samples were characterized by powder X-ray diffraction (XRD), simultaneous thermogravimetric/differential thermal analysis (TG/DTA), Fourier Transform Infrared (FT-IR) and Scanning electron micrograph (SEM).

• 한국CDE학회논문집
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• 제22권2호
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• pp.162-171
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• 2017

Unmanned military vehicles (UMVs) are most commonly characterized as dealing with dull, dirty, and dangerous tasks with automation. Although most of the UMVs are designed to a high degree of autonomy, the human operator will still intervene in the robot's operation, and teleoperate them to achieve his or her mission. Thus, operator capacity, together with robot autonomy and user interface, is one of the most important design factors in the research and development of the UMVs. Further, communication may affect the operator task performance. In this paper, we analyze the operator performance and the communication effects on the operator performance by using the extended Petri nets, called OTSim nets. The OTSim nets was designed by the authors, being extended using pure Petri nets.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.144-151
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• 2006

Sound generated from a moving vehicle often carries information on the condition of vehicle, for example, whether it has faults or not, where the fault exists. The latter is possible especially by MFAH(moving frame acoustic holography) and beamforming method. MFAH is applicable to the sound source of pure tone or narrow band noise. For the beamforming method, we have to know what kind of wave the sound source radiates, for example, plane wave or spherical wave. That is, whether the above methods are applicable depends on the characteristics of sound source. To apply these methods to the fault detection, we have to know the characteristics of wave from faults. In this research, a machine diagnosis technique based on the above holographic approaches is introduced to find the position of faults. The signal due to faults is modeled based on the fact that the faults radiate impulsive noise, and analyzed in time and frequency domain. The way how MFAH and beamforming method can be used is introduced to find the position of source.