• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.4
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• pp.437-448
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• 2000

In this study, a numerical analysis method for soil-pile interaction in frequency domain problem is presented. The total soil-pile interaction system is divided into two parts so called near field and far field. In the near field, beam elements are used lot a pile and plain strain finite elements for soil. In the far field, dynamic fundamental solution for multi-layered half planes based on boundary element formulation is adopted lot soil. These two fields are coupled using FE-BE coupling technique. In order to verify the proposed soil-pile interaction analysis, the dynamic responses of pile on multi-layered half planes are simulated and the results are compared with the experimental results. Also, various numerical analyses of piles considering different conditions of soil-pile interaction system are performed to examine the dynamic behavior of the system. It has been found that the developed method which satisfies the radiation conditions of multi-layered half planes can be applied to various structure systems effectively in frequency domain.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.1
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• pp.75-85
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• 2000

When applying a system identification technique, which incorporates an experimental model to a corresponding finite element model of a structure, one of the major problems is the large difference in the numbers of degrees of freedom (dof) between the two models. While there are large number of dofs in a finite element model, the number of measurement points is practically limited. So it is very difficult to incorporate them. Especially rotational dofs are hard to measure. In this study a method is presented for estimating structural dynamic responses at unmeasurable locations in frequency domain. The proposed method is tested numerically and the feasibility for practical application has been demonstrated through an example structure under moving loads, where translational and rotational dofs of beam at a center point are estimated from the partial measurements of responses at accessible points.

• Animal cells and systems
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• v.4 no.3
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• pp.299-304
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• 2000

In the present paper, the immunostimulatory effects of the extracellular products (ECP) from Mycobacterium spp. and various adjuvants on the non-specific immune responses of Nile tilapia, Oreochromis nilotica, were examined. Nile tilapia were immunized by injecting ECP of Mycobacterium spp. (strain TB40, TB267 or the type strain Mycobacterium marinum) into their swim bladders. A variety of adjuvants like as Freund s complete adjuvant (FCA), Freund's incomplete adjuvant (FIA) and Titremax were similarly injected into additional groups of tilapia. The number of nitroblue tetrazolium (NBT)-positive cells observed in the swim bladder of the immunized fish was signigicantly increased by the fourth day post-immunization. By day 8, the numbers of NBT-positive cells were fewer in fish immunized with ECP from mycobacteria strains TB40 or TB267 than those immunized with ECP from M. marinum or fish injected with FCA or FIA. The level of Iysozyme activity detected in the serum of fish 40 alter immunization with ECP from various Mycobacterium spp. was also significantly higher than that found in the serum of the control fish. Head kidney macrophages showed enhanced reduction of NBT when cultured in vitro with 1 $\mu$ g/ml of ECP. Concentrations greater than this (10 or 100 $\mu$g/ml) were found to suppress the reduction of NBT by the macrophages. ECP from Mycobacterium spp. and the various adjuvants used in the study all appear to be good activators of the non-specific immune responses of Nile tilapia.

• Journal of Veterinary Clinics
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• v.17 no.2
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• pp.359-367
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• 2000

The aim of this study was to evaluate the effects of propofol on cortical electroencephalogram (EEG) in seven dogs. Propofol infusion was accomplished from low concentration to high concentration in series, and each concentration was infused for 20 minutes (M0: 0, M0.5: 0.5, M1.0:1.0, and M1.5: 1.5 mg/kg/min of infusion rate). EEG was recorded via needle electrode placed at Cz, which was applied to International 10-20 system. Arterial blood pressure. blood gas analysis and ECG were also measured. Hoemodynamics, Pa$CO_2$, PaO$_2$, heart rate and respiratory rate were variable, but were net significant(p>0.05). The power spectra of EEG in every concentration was compared wish those of control (MO). The powers at a1l frequencies at M1.0 and Ml.5 were decreased. Especially, the powers of the frequencies over 20 Hz were significantly decreased (p<0.O5). Powers at frequencies between 8 and 15Hz at MO.S were significantly increased (p<0.05) in response to the painful stimuli. It was inferred that they may reflect activity of the brain which is consciously processing the external Stimuli. Like the Power spectra, al1 the band powers of He EEG ($\delta$ 1-4, $\theta$4-8, $\alpha$ 8-13, $\beta$L13-21. $\beta$H 21-30, \ulcorner 30-50, and total 1-5OHz) were decreased in proportion to the increase of infusion rate at M1 .0 and M1.5. Especially, decrease of $\beta$H and ${\gamma}$ were significant(p<0.01). At M0.5, $\alpha$ band was significantly increased(p<0.05) among all the bands. Seizure activities which were concide with occurrence of spike wave were shown in all dogs at Ml .0 and M1.5.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11
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• pp.3534-3543
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• 2000

We believe in terins of information service systems that one of the best ways to develop a large scale database service system is to integrate the service capability of the Web and the dta management facility of database management systems in a complementary fashion. In such integation a database gateway in the core component, the web-database gateway accesses database management systems to serve the requests represented by using the Web technology. We designd BADA/Web be independent from the Web and DBMS and much as possible, which minrrizes the performance overhead caused by connecting database management systems and makes BADA/Web portable. BADA/Web incorporates TCL into a ibrary of it and handles concurrent requests efficiently. In this paper we describe our desingn and implementation experience in integrating the Web and BADA-III We evaluate the performance of BADA/Web by measuring and companing the latency and average response time for a simple query and also explore the effects of BADA/Web with some synthetie queries .

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.6
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• pp.255-261
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• 2005

Recently, the RF inductive discharge or inductively coupled plasma continues to attract growing attention as an effective plasma source in many industrial applications, the best known of which are plasma processing and lighting technology. To the point of lighting sources, the ring-shaped electrodeless fluorescent lamps utilizing an inductively coupled plasma have been objects of interest and research during the last decades, mainly because of their potential for extremely long life, high lamp efficacies, rapid power switching response. In this paper, maxwell 3D finite element analysis program (Ansoft) was used to obtain electromagnetic properties associated with the coil and nearby structures. The electromagnetic emitting properties were presented by 3D simulation software operated at 250 kHz and some specific conditions. The electromagnetic field in the ferrite core was shown to be high and symmetric. An LS-100 luminance meter and a Darsa-2000 spectrum analyzer were used in the experiment. According to data on the lamp tested using high magnetic field ferrite, the optical and thermal wave fields were shown to be high around the ring-shaped electrodeless fluorescent lamp. The optical or light field was high at the center of the bulb rather than around the ferrite core. The light conditions of the bulb were assumed to be complex, depending on the condition of the filler gas, the volume of the bulb, and the frequency of the inverter. Our results have shown coupling between the gas plasma and the field of the light emitted to be nonlinear.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.65-72
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• 2000

The study investigated the effects of base curve radius art the fit of thin, mid-water contact lenses. It was found that central corneal curvature(as measured with the keratometer) was not predictive of the best fitting base curve. Proper lens fit may be the single most important factor that ultimately determines the success of contact lens wear. Comfort, vision, and physiological response are all dependent on the fit of the lens. The percent of optimal fits was highest with the 8.4 mm base curve lens for all three ranges of keratometry values. When fit with the 8.4 mm lens. For most eyes, fitting a flatter lens led to greater decentration, decreased comfort, and no increase in lens movement. The 8.4 mm lens was found to provide on "optimal" fit in over 60% of eyes tested and a fit of "good" or "better" in nearly 90% of eyes tested. Comparisons of different manufactures' lens found that similiar lenses do not always fit in the same way due to subtle design and production differences. Therefore, different products may require different base curve radii to fit the same patient. This is even true when water content, center thickness, and diameter are approximately the same. A praditioner fitting a new patient in this lenses should begin with the 8.4 mm base curve radius.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2006.02a
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• pp.116-123
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• 2006

생물체의 cDNA를 유리기판위에 고밀도로 첨착 시킨 유전자 칩과 정량적인 방법으로 개별 유전자 발현을 진단 가능한 Real- time PCR (실시간 고분자중합연쇄반응 기술) 기법은 첨단 의학분야와 신약개발 및 독성유전체 연구분야에 활발히 도입되고 있는 기술이다. 본 발표의 첫 번째 부분에서는 유전자칩 에서 얻어진 유전자 발현패턴분석에 기반한 바이오마커 선정 및 real time PCR에 의한 확증 관련 기술 과 유전자칩에서 얻어지는 수많은 데이터를 재정렬 및 다양한 분석기법과 display기술을 활용하여 광범위한 화학물질에 대한 독성효과 분석을 가능하게 해주며, 특정 독성물질에 대한 관련유전자 그룹 발견 및 독성영향에 따른 분류방법에 관한 결과를 발표할 것이다. 또한 바이오마커 활용의 하나로 박테리아세포 기반 바이오센서 제작및 세포칩 개발등에 대한 결과도 추가될 것이다. 두 번째 부분에서는 non-model organism(유전체정보가 확보되지 않은 생물체)인 송사리를 이용하여 새로운 2K 유전자칩을 개발하고, 여기서 각종 화학물질에 대하여 얻어진 수많은 유전자칩 분석 데이타를 활용하여 각각의 화학물질이 보여주는 독성효과를 매우 효과적이고 쉽게 이해할 수 있는 display기술을 개발, 적용함으로써 유전자칩 발현에 기반한 화학물질 독성 screening 및 specificity discrimination을 가능케 하는 예가 발표될 것이다. 이 연구에서 개발한 송사리 유전자칩은 간조직의 RNA를 직접 cDNA화 하는 방식을 취하고 있어 전체 송사리의 유전정보를 필요로 하지 않아 비용 및 효율에서 전체 송사리의 유전정보를 얻는 비용과 노력을 취하지 않고 간에서 발생하는 독성학적 영향 및 유전자의 발현정도를 정밀하고 효율적인 방법으로 얻어 낸다. 현재 2000여개의 cDNA유전자중 50%이상의 유전자가 17베타에스트라디올, 페놀, 노닐페놀, 비스페놀, 감마레이조사, 잔류약품중 이보프란, 다이클로펜악, 농약중의 파라???R, 돌연변이 유발물질 중의 이티비알, 금속류중의 카드뮴을 통해 발현양상과 특정 캐미칼별 발현 특이성이 조사되었고, 이들 유전자는 염기서열 분석을 통해 염기서열이 분석되었으며, 미국 NCBI의 유전자 은행과의 비교를 통해 일부유전자는 새로운 유전자로 밝혀지고 있다. 또한 이 발표에서는 소염진통제계열 의약품인 dichlofenac 이 송사리의 각종 조직에 미치는 독성영향을 Real-time PCR을 이용하여 대표적 스트레스 유전자의 발현에 미치는 영향에 대한 분석 예가 발표될 것이다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.8
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• pp.42-47
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• 2000

Long-wavelength infrared (LWIR) detectors made of self-assembled quantum dots embedded in the channel region of high electron mobility transistor (HEMT) is demonstrated. Above 180 K, the detector shows low dark currents due to strong confinement effect of electrons in InAs quantum dots and exhibits the broad spectral response ranging from 7 mm to 11 mm. The peak detectivity ($D^*$) of $1.93{\times}10^{10}cmHz^{1/2}/W$ is obtained at 9.4 mm. The photocurrent characteristics as a function of applied bias are similar to that of normal FETs, while the photocurrent decreases as the applied electric field exceeds $2{\times}10^3V/cm$ because of the increased dark current.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.9
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• pp.1-6
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• 2000

Utilizing impurity free vacancy diffusion (IFVD) method, area selective intermixing of InGaAs/InGaAsP multi-quantum well (MQW) structure was done. After this, wavelength division demultiplexing waveguide type photodetectoers was integrated and measured. It showed large blue shift in bandgap due to intermixing of MQW. Photodetectors are based on typical p-i-n structure and devices having large and small bandgap areas line up linearly. Width of waveguide and length of each photodetector are 20 and 250 ${\mu}m$, respectively, TE/TM polarized light from tunable laser was butt-coupled to the photodetector and spectral response was measured. Photodetectors can demultiplexing 1480 and 1550 nm wavelength.