• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.565-568
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• 2000

This paper describes on the temperature characteristics of a SDB(silicon-wafer direct bonding) SOI(silicon-on-insulator) Hall sensor. Using the buried oxide $SiO_2$ as a dielectrical isolation layer, a SDB SOI Hall sensor without pn junction isolation has been fabricated on the Si/$SiO_2$/Si structure. The Hall voltage and the sensitivity of the implemented SOI Hall sensor show good linearity with respect to the applied magnetic flux density and supplied current. In the temperature range of 25 to $300^{\circ}C$, the shifts of TCO(temperature coefficient of the offset voltage) and TCS(temperature coefficient of the product sensitivity) are less than $\pm 6.7$$\times$$10^{-3}$/$^{\circ}C$ and $\pm 8.2$$\times$$10^{-4}$/$^{\circ}C$respectively. These results indicate that the SDB SOI structure has potential for the development of a silicon Hall sensor with a high-sensitivity and hip high-temperature operation.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.73-76
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• 2000

A Scene Based Technique(SBT) that corrects linear array infrared detector's nonuniformity is proposed. Basically, this technique dispenses with using temperature references on a linear array infrared detector. To correct the nonuniformity of infrared images, we use three methods. Firstly, we detect bad channels by using the information which is cumulated all the same line pixels. Secondly, a variable window method is applied to compensate more accurately. Thirdly, an adaptive method which updates gain and offset coefficient is used only on a stationary region. These results are demonstrated on a computer simulation with various images. As a result, the nonuniformity is corrected completely, so that images are enhanced and PSNR(peak signal to noise ratio) is improved much.

• Journal of Technology Innovation
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• v.15 no.2
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• pp.1-24
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• 2007

In this study, we estimated a CES production function for the Korean economy. We have found in the empirical results that the elasticity of the factor substitution is less than one and that the Korean economy exhibits labor-saving technological progress. In addition, we obtained the regression coefficient of R&D investment on technological change, i.e., the elasticity of R&D investment with respect to the technological change was 0.26% point. It implies that if R&D stock increases by 1%, labor efficiency increases 0.26% point through technological progress which is Hicksian non-neutral. It confirms that innovation-based growth strategy by increasing R&D investment would be effective on the one hand. Some policy consideration on the other might be needed for an increase in employment which is offset by technological progress.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1688-1690
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• 2001

The mechanical characteristics of XLPE cable is basic to the installation design. Especially, snake and offset design require accurate coefficient of linear expansion($\alpha$), Young's modulus(E) and bending stiffness(El) of the cable. In this paper, $\alpha$, E and El of 345kV XLPE cable was measured by experimental setup, and verified by measuring axial tension and lateral displacement in snake installation.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.73-76
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• 2002

In this paper we present an integrated Hail sensor It for fan motors, fabricated in industrial bipolar process. As a discrete Hall sensor and signal processing circuitry In the fan motor system were Integrated into single chip a temperature dependence of Hall sensitivity and Hall offset voltage can be compensated and cancelled by on-chip circuitry. We Propose a novel temperature compensation of Hall sensitivity with negative temperature coefficient (TC) using the differential amplifier gain with Positive TC. After a package of the chip was sealed using a plastic Package 20 Pins, the thermal and magnetic characteristics were investigated. The obtained experimental results are in agreement with analytical predictions and have more excellent performance than\ulcorner conventional the fan motor system using discrete Hall sensor.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.8
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• pp.99-103
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• 2004

Aperture has been employed on the ground plane in the Hairpin resonator. Aperture made by etching the part of the ground effected coupling coefficient and then quality factor of Hairpin resonator has been increased. When the hair pin oscillator using aperture has been compared with the conventional hair pin oscillator using microstrip, it has been improved the phase noise about 19dBc ＠100KHz. Oscillation frequency of the hair pin oscillator using aperture has been 5.83GHz band and output power is -4.33dBm.

• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.69-73
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• 2008

초분광영상을 이용한 정량적인 분석이나 분광라이브러리를 이용한 목표물의 탐지를 위해서는 복사보정이 필수적이지만 사전 검보정 자료가 없는 센서의 경우 절대 복사 보정을 실시할 수 없다. 본 연구의 목표는 사전 검보정 자료가 없는 지상 초분광 카메라 (SOC700) 영상의 화소값을 spectroradiometer의 radiance로 변환하기 위한 상대 변환계수(gain, offset coefficient)를 산출하고 그 적합성을 판단하는 것이다. 초분광영상의 DN과 동시에 측정된 radiance의 밴드별 선형 회귀분석을 통하여 상대 radiance 변환계수를 산출하였다. 산출된 선형 회귀식의 적합도($R^2$)는 대부분이 0.9 이상으로 매우 양호하였으며 상대 radiance를 이용할 경우 상대 분광반사율 획득이 가능하며 이를 통해 보다 초분광영상에 적합한 정량적인 분석을 할 수 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4324-4342
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• 2014

Previous papers analyzed the throughput performance of the CDMA ALOHA system in Rayleigh fading channel, but they assume that the channel coefficient of Rayleigh fading was the same in the whole packet, which is not realistic. We recently proposed the finite-state Markov channel (FSMC) model to the throughput analysis of DS uncoded CDMA/unslotted ALOHA networks for fixed length data traffic in the mobile environment. We now propose the FSMC model to the throughput analysis of coded DS CDMA/unslotted ALOHA networks with variable length data traffic and one or two user classes in the mobile environment. The proposed DS CDMA/unslotted ALOHA wireless networks for two user classes with access control can maintain maximum throughput for the high priority user class under high message arrival per packet duration.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.2
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• pp.1-9
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• 1995

This paper suggests a numerical method that creates and varies hull form geometry of underwater vehicle. That is, it induces the cylindrical underwater vehicle from principal dimensions-total length, the length of parallel middle body, the coefficient defining entrance & run parts etc.-and represents using NURBS curve. Also, each section of hull form is varied by user interface and Sectional Area Curve is generated.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.85-89
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• 2004

The wave interactions with fully submerged and floating dual buoy/vertical porous membrane breakwaters has been investigated in experimentally to validate the developed theory and numerical method in the previous study, in which multi-domain hydro-elastic formulation was carried out in the context of linear wave-body interaction theory and Darcy's law. It is found that the experimental results agrees well with the numerical prediction. Transmission and reflection can be quite reduced simultaneously especially in the region of long waves. The properly tuned system to incoming waves can effectively dissipate wave energy and also offset each other between incident and scattered waves using its hydro-elasticity and geometry.