• Medical Lasers
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• 제8권2호
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• pp.64-73
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• 2019

Background and Objectives The effectiveness of many physiotherapy modalities in reducing subcutaneous fat has been investigated in numerous previous studies. However, to the best of our knowledge, there have been no attempts to determine the effectiveness of physiotherapy modalities in body contouring. The present report determined the effect of 448-kHz capacitive resistive monopolar radiofrequency (CRMRF) in a porcine model. Materials and Methods This study investigated the effect of selective destruction of the subcutaneous fat layer in abdominal fat tissue using CRMRF. The effects of two types of CRMRF (capacitive electric transfer (CET) and resistive electric transfer (RET)) treatment were evaluated using regular digital photography in addition to thermal imaging evaluation, ultrasound measurement, hematological evaluation, and histologic analyses (H&E (hematoxylin and eosin), Oil red O, and immunohistochemistry staining). Results Preclinical evaluation was performed to obtain the data for comparison of the safety and efficacy of the subcutaneous fat reduction after applying CRMRF using CET and RET. After treatment, the thermal transmission was effective, and a 42-47℃ temperature change was observed in the fat layer while an approximately temperature of 42℃ was confirmed on the skin surface. Moreover, after the application of both types of CRMRF treatment, fibrotic septa were observed in the adipose tissue induced by heat at the treatment sites. TUNEL staining was also performed to confirm the process of apoptosis in the adipocytes. Conclusion These results suggest that both CET and RET for CRMRF treatment are safe and effective for subcutaneous fat reduction in a porcine model.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1985년도 춘계학술대회
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• pp.9-12
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• 1985

This paper covers the design and implementation process of RF hypertermia system for cancer therapy. Among many hyperthermic methods, RF capacitive heating method is discussed because it can heat the deep-seated tumors selectively. The RF power oscillator and its applicators were designed and implemented. And the experiments were performed with agar phantom and dog to prove that the system can heat any depth selectively. And the electrical safety and appropriateness of clinical application was proved through the human living-body test.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.491.1-491.1
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• 2014

Heteroatom phosphorous-doped graphene aerogel (PGA) with high surface area is successfully synthesized via hydrothermal method for high power and energy supercapacitors, including the advantage of three dimensional internetwork and constitutive graphene skeletons. The morphology of PGA was investigated by the scanning electron microscope, transmission electron microscope. The chemical structure and circumstances were confirmed by Raman and X-ray photoelectron spectroscopy, the phosphorus is successfully incorporated with the graphene sheets. As evidenced by electrochemical measurements, cyclic voltammetry and galvanostatic charge discharge, the hierarchically PGA has an unprecedented high capacitance, which contributes to the excellent high-rate performance of this material for supercapacitor application.

• IEIE Transactions on Smart Processing and Computing
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• 제4권3호
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• pp.183-188
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• 2015

A 10-bit 10MS/s low power consumption successive approximation register (SAR) analog-to-digital converter (ADC) using a straightforward capacitive digital-to-analog converter (DAC) is presented in this paper. In the proposed capacitive DAC, switching is always straightforward, and its value is half of the peak-to-peak voltage in each step. Also the most significant bit (MSB) is decided without any switching power consumption. The application of the straightforward switching causes lower power consumption in the structure. The input is sampled at the bottom plate of the capacitor digital-to-analog converter (CDAC) as it provides better linearity and a higher effective number of bits. The comparator applies adaptive power control, which reduces the overall power consumption. The differential prototype SAR ADC was implemented with $0.18{\mu}m$ complementary metal-oxide semiconductor (CMOS) technology and achieves an effective number of bits (ENOB) of 9.49 at a sampling frequency of 10MS/s. The structure consumes 0.522mW from a 1.8V supply. Signal to noise-plus-distortion ratio (SNDR) and spurious free dynamic range (SFDR) are 59.5 dB and 67.1 dB and the figure of merit (FOM) is 95 fJ/conversion-step.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.77-78
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• 2003

The surface evenness and texture of textile products are closely related with the irregularity of yarn thickness which has an important role to influence the quality and the process efficiency. For measuring yam thickness the capacitive method is known to dominate the market, delivering results that are in a close relation with the mechanical properties of yarn, while the optical method offers information that seems related rather with the apparent quality of yarn. If a thin light beam is applied for the optoelectrical measurement, it is very possible that this method can provide us with important information which is not obtainable from the capacitive type measurement. This paper reports the results of a study about the yarn thickness and its variation on the basis of a new measurement system using a laser slit beam. Analysis of the new system confirms that we can extract new information on the yarn irregularity ranging into much short wavelengths. Even the visual shade created by the yam doubling and twisting can be measured and represented well. Depending on the yam types, the thickness measurements show their own characteristics.

• 한국인터넷방송통신학회논문지
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• 제11권2호
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• pp.225-229
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• 2011

본 연구에서는 환경 모니터링을 위한 정전용량형 압력센서를 저온동시소성세라믹 (LTCC) 기술을 이용하여 제작하였다. LTCC 기술은 실리콘 기반의 기술에 비하여 낮은 생산 단가, 높은 수율, 3차원 구조물의 용이한 제작성 등으로 인하여 센서 응용분야에서 중요한 역할을 담당하고 있으며, 특히 열악한 외부환경에 적합한 물질이다. 400 ${\mu}m$ 두께 삼차원 구조의 LTCC 다이어프램은 NEG사의 MLS 22C 상용 파우더를 이용하여 100 ${\mu}m$ 두께의 그린쉬트를 적층하고 동시소결하여 제작하였다. 제작한 다이어프램은 공동의 면적에 따른 센싱특성을 평가하기 위하여 각각 25, 49 $mm^2$의 두 종류를 제작하였다. 정전용량형 압력센서를 구현하기 위하여 상부에는 열증착기를 이용하여 Au 금속박막을 증착하였고 하부에는 상용 알루미늄막을 압착하였다. 압력에 따른 센싱특성을 평가하기 위하여 제작된 측정시스템을 이용하여 0~30 psi의 압력을 가변하여 압력센서의 정전용량 변화를 측정한 결과 두 센서 모두에서 선형적인 센싱 특성을 나타냄을 확인하였다.

• 멤브레인
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• 제27권3호
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• pp.240-247
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• 2017

본 연구에서는 막 결합형 축전식 탈염공정에 적용을 위해 폴리비닐플루오라이드를 고분자 지지체로 사용하여 양이온 및 음이온교환수지를 배합하여 제작된 불균질 이온교환막을 탄소전극에 결합하여 염 제거 효율을 알아보고자 하였다. 불균질 이온교환막의 배합 조건은 용매, 고분자 지지체, 이온교환수지를 7 : 2 : 1의 무게 비율로 하였으며 탄소전극에 직접 캐스팅 하였다. 운전조건으로 공급액은 주로 NaCl 수용액에 대하여 흡착전압, 시간, 공급액의 농도, 유속, 탈착전압, 시간 등에 대하여 염 제거 효율을 측정하였으며 이 외에 $CaCl_2$과 $MgSO_4$ 수용액에 대하여서도 측정하였다. 대표적으로 NaCl 100 mg/L 용액의 15 mL/min에서 1.5 V, 3분의 흡착조건, -0.1 V, 3분의 탈착조건에서 98%의 염 제거 효율을 보였으며, $CaCl_2$과 $MgSO_4$는 100 mg/L, 15 mL/min에서 1.2 V, 3분의 흡착조건, -0.5 V, 5분의 탈착조건에서 각각 70, 59%의 염 제거 효율을 보였다.

• Radiation Oncology Journal
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• 제7권2호
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• pp.313-320
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• 1989

고주파유전가열 장치는 심부까지도 효과적인 가온이 가능하여 각족 심부암의 치료에 응용되고 있다. 그러나 한쌍의 전극을 평행으로 대칭 배열하는 현재의 방법은 신체의 일측으로 편재되어 있는 병소에는 배열 자체가 불안정할 뿐만 아니라, 노출된 동측 피부표면이 과열되며 종양의 가온 양상도 만족스럽지 못한 경우가 많아서 임상 적응에 난점으로 지적되고 있는 실정이다. 저자들은 상기와 같은 병소를 보다 안전하고_도 효과적으로 가온하기 위하여 두 전극간에 일정한 각도를 이루는 새로운 전극 배열을 시도하였다. 즉, 임상 적용 가능성을 고려한 $60^[\circ},\;90^{\circ}\;및\;120^{\circ}$로 전극을 배열하고 모형 (phantom)에서 가온 실험을 행하여 이같은 각도 배열에서의 온도 분포의 특성을 평가할 수 있었고, 일측에 편재된 병소를 가진 3예의 환자에게 각도 배열로 온열치료를 시행한 결과 환자의 수용성, 부작용 및 온도분포에 있어서 만족할 만한 결과를 얻을 수 있었다. 따라서 저자들이 시도한 전극의 각도배열은 일측에 편재된 병소를 유전 가열 장치로 가온 할 때 평행 배열이라는 한계점을 극복할 수 있는 새로운 방법으로서 매우 고무적으로 생각된다.

• Journal of Mechanical Science and Technology
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• 제20권4호
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• pp.554-560
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• 2006

This paper describes the demonstration of successful fabrication and initial characterization of micromachined pressure sensors and micromachined jets (microjets) fabricated for use in macro flow control and other applications. In this work, the microfabrication technology was investigated to create a micromachined fluidic control system with a goal of application in practical fluids problems, such as UAV (Unmanned Aerial Vehicle)-scale aerodynamic control. Approaches of this work include: (1) the development of suitable micromachined synthetic jets (microjets) as actuators, which obviate the need to physically extend micromachined structures into an external flow; and (2) a non-silicon alternative micromachining fabrication technology based on metallic substrates and lamination (in addition to traditional MEMS technologies) which will allow the realization of larger scale, more robust structures and larger array active areas for fluidic systems. As an initial study, an array of MEMS pressure sensors and an array of MEMS modulators for orifice-based control of microjets have been fabricated, and characterized. Both pressure sensors and modulators have been built using stainless steel as a substrate and a combination of lamination and traditional micromachining processes as fabrication technologies.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1371-1379
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• 2013

Application of induction machines in wind turbine driven generators is a good alternative due to their good characteristics such as efficiency, reliability and low cost. Nevertheless, when isolated operation is required, the application of external capacitive bank, connected to the stator windings, to provide self-excitation results in a rather complex analysis. This paper presents an analysis of self-excited induction generator connected to a load either directly or by an intermediate of a power converter. At first a dynamic model of the induction generator accounting for magnetic saturation is developed. Then a number of balanced and unbalanced capacitors, passive and active loads are verified. Experimental results obtained from laboratory tests are compared to those simulated; the two are shown to be in good agreement.