• 한국철도학회논문집
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• 제13권3호
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• pp.309-316
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• 2010

철도선형에서 평면곡선과 종곡선의 경합은 차량의 주행안정성, 승차감, 그리고 궤도유지보수비에 많은 영향을 끼친다. 그러나 신선건설 혹은 기존선 개량 시 기존의 고정점(터널, 교량, 분기기, 전차선주 등)들과 예기치 않은 주위 환경조건들에 의해 부득이 부설될 경우가 발생된다. 본 연구에서는 평면곡선과 종곡선 경합 시 승차감 측면에서의 최적 평면선형 설계를 위한 승차감 목적함수를 도출하고 차량동역학 해석을 통해 검증하였다. 또한 제시된 승차감 목적함수를 이용해 승차감이 최대가 되는 선형조건을 간단히 평가할 수 있는 해법알고리즘을 제시하였다.

• 약학회지
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• 제55권1호
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• pp.45-48
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• 2011

Traditional medicines usually use combinational formula that are prepared by mixing different varieties of medicinal herbs and boiling them in water to yield a decoction. In recent years a modified method has been proposed and practiced wherein the individual herbs are boiled with water separately and later these extracts are mixed together for use. We attempted to evaluate their equivalence in terms of its polyphenol contents and DPPH radical scavenging activity. The polyphenol contents as well as the DPPH radical scavenging activities were very similar to each other.

• 통합자연과학논문집
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• 제3권2호
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• pp.117-121
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• 2010

Silicon quantum dots base on photoluminescent porous silicon were prepared from an electrochemical etching of n-type silicon wafer (boron-dopped<100> orientation, resistivity of 1~10 ${\Omega}-cm$) and used as a alcohol sensor. Silicon quantum dots displayed an emission band at the wavelength of 675 nm with an excitation wavelength of 480 nm. Photoluminescence of silicon quantum dots was quenched in the presence of alcohol vapors such as methanol, ethanol, and isopropanol. Quenching efficiencies of 21.5, 32.5, and 45.8% were obtained for isopropanol, ethanol, and methanol, respectively. A linear relationship was obtained between quenching efficiencies and vapor pressure of analytes used. Quenching photoluminescence was recovered upon introducing of fresh air after the detection of alcohol. This provides easy fabrication of alcohol sensor based on porous silicon.

• 통합자연과학논문집
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• 제3권2호
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• pp.78-83
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• 2010

DBR/Host dual porous silicons containing DBR and host structure were prepared and their optical properties were characterized using Ocean Optics spectrometer. In this dual porous silicon, single porous silicon layer was used as host layer for possible biomolecule and drug materials and DBR porous silicon layer was used for signal transduction due to the recognition of molecules. Optical reflection spectrum of dual porous silicon displayed only DBR reflection but Fabry-Perot fringe pattern. DBR reflection band of dual porous silicon shifted to the shorter wavelength as the etching time of host layer increased. Cross-sectional FE-SEM image of dual porous silicon displayed a thickness of about 20 micrometer for DBR porous silicon layer. Developed etching technology could be useful to prepare DBR porous silicon which exhibited specific reflection resonance at the required wavelength and to provide an label-free biosensors and drug delivery materials.

• 대한물리치료과학회지
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• 제6권2호
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• pp.997-1005
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• 1999

To evaluate the effect of winter intensive training on pulmonary function in high school baseball players, comparisons of various ventilatory parameters were made before and 3-3.5 months of winter intensive tranining. The subjects were 18 members of a high school baseball players with mean age and career of 6.3 and 7.3 years, respectively. The following were mainly observed by spirometry for the study ; respiratory rate, vital capacity(VC), maximum voluntary ventilation(MVV), forced vital capacity (FEV1%) and forced mid-expiratory flow (FEF25-75%). The result obtained are summarized as follow. 1) Resipratory rate, tidal volume, forced vital capacity, 1FEV%, FEF50% and FEF75% showed no significant difference between before and after. 2) MVV in after was significantly(p<0.001) increased to 166 L/min comparing with 136L/min in before. 3) 1FEV in after was significantly(p<0.05) increased to 4.46L comparing with 3.76L in before. 4) PEF in after was significantly(p<0.05) increased to 10.40 L/sec comparing with 9.18 L/sec in before.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.505-506
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• 2006

In this paper, the linearization technique for CMOS low-noise amplifier (LNA) using the derivative superposition method through the multiple gated transistors configuration is presented. LNA based on 0.13um RF CMOS process has been implemented with a modified cascode configuration using multiple gated common source transistors to fulfill a high linearity. Compared with a conventional cascode type LNA, the third order input intercept point (IIP3) per DC power consumption (IIP3/DC) is improved by 3.85 dB. The LNA achieved 2.5-dBm IIP3 with 13.4-dB gain, 3.6 dB NF at 2.4 GHz consuming 8.56 mA from a 1.5-V supply.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권4호
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• pp.383-390
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• 2014

This paper presents an excitatory CMOS neuron oscillator circuit design, which can synchronize two neuron-bursting patterns. The excitatory CMOS neuron oscillator is composed of CMOS neurons and CMOS excitatory synapses. And the neurons and synapses are connected into a close loop. The CMOS neuron is based on the Hindmarsh-Rose (HR) neuron model and excitatory synapse is based on the chemical synapse model. In order to fabricate using a 0.18 um CMOS standard process technology with 1.8V compatible transistors, both time and amplitude scaling of HR neuron model is adopted. This full-chip integration minimizes the power consumption and circuit size, which is ideal for motion control unit of the proposed bio-mimetic micro-robot. The experimental results demonstrate that the proposed excitatory CMOS neuron oscillator performs the expected waveforms with scaled time and amplitude. The active silicon area of the fabricated chip is $1.1mm^2$ including I/O pads.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제21권4호
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• pp.382-387
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• 1999

The concept of PCA(Patient Controlled Analgesia) was first described in 1968, by Sechzer. The earliest descriptions of actual self-administered PCA machines were by Forrest et al. In gastric bypass surgery, cesarian section, orthopedic surgery etc, PCA is widely used in the control of postoperative pain. Previous Studies have shown that PCA provides effective pain-control for the postoperative patient. The postoperative pain-control is a problem that should be solved in surgery. Especially in orthognathic surgery, it is not same as in the case of maxillofacial trauma surgery or of tumor surgery: most orthognathic surgery patients are under operation not accustomed to pains, and difficulties in pain-complaint due to IMF(Intermaxillary fixation), postoperative nausea, and vomiting are additional problem. In this study, we have compared PCA and IM analgesics with respect not only to time request but also to the quality of postoperative pain control.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제21권4호
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• pp.366-369
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• 1999

관골 골절을 분류할 때 주위의 해부학적인 구조물과 연관해서 기능적인 면에 중점을 두어야 하므로 복시나 내안증같은 합병증이 나타날 수 있는 안와골절을 포함하는 분류를 해야한다. 관골 골절의 변위에 따라 나타나는 합병증의 양상이 매우 다양하므로 진단에 도움이 될 수 있도록 지속적인 연구가 필요할 것으로 사료되며, 초창기에 이러한 임상적인 합병증이 나타나지 않더라도 추후에 발생할 가능성이 있기 때문에 이를 간과해서는 안될 것으로 사료된다.

• 가정과삶의질연구
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• 제29권1호
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• pp.21-40
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• 2011

This research is intended to find out the causes of the career interruption of highly-educated housewives, their experiences of caring for their children after career interruption, their psychological conflicts and coping strategies, and their attitudes toward reemployment. The participants were university-graduated housewives in their thirties who have pre-school children older than 2 years. The participants in this research consisted of twenty-nine participants. The essence of this study is the belief system that career and maternal roles are not compatible. Specifically, the participants possessed a certain motherhood ideology, so they gave up working in order to care for their children, deferring their careers for a while. The participants had ambivalent feelings about working mothers, and described their children by highlighting their negative aspects. Additionally, the participants experienced persistent conflicts about developing their careers and caring for their children during their period of career interruption. The participants seemed to possess a vague sense of hope about their careers, and their attitudes toward their careers were ambiguous in the past, present, and even in the future.