Earticle

In semiconductor memory, the kinds of voltage generator are high voltage generator, negative voltage generator, drain voltage generator and etc. The relevant circuits supported voltage generator, are clock generator, sense amplifier, voltage regulator and etc. The voltage generator consists of MOS diodes and MOS capacitors. To get the out voltage with sufficient charge, the MOS capacitors are big size. These MOS transistors can be adapted only on the EEPROM process. Thus, in this paper, we designed stacked metal capacitor. This capacitor is small size but can get much capacitance. This capacitor is designed to comb type using metal-line and poly-line. The size of designed capacitor is 208×52㎛2 and the capacitance is about 4㎊. The stacked metal capacitor can get much capacitance of 5～6 times than single plane capacitor. Also this capacitor will be easy adapted in sub-micro process technology of semiconductor memory. And this capacitor can be adapted on all memory process.

Although the compact capacitance model of point tunneling types of tunneling field-effect transistors (TFET) has been proposed, those of line tunneling types of TFETs have not been reported. In this study, a compact capacitance model of an L-shaped TFET (LTFET), a line tunneling type of TFET, is proposed using the previously developed surface potentials and current models of P- and L-type LTFETs. The Verilog-A LTFET model for simulation program with integrated circuit emphasis (SPICE) was also developed to verify the validation of the compact LTFET model including the capacitance model. The SPICE simulation results using the Verilog-A LTFET were compared to those obtained using a technology computer-aided-design (TCAD) device simulator. The current-voltage characteristics and capacitance-voltage characteristics of N and P-LTFETs were consistent for all operational bias. The voltage transfer characteristics and transient response of the inverter circuit comprising N and P-LTFETs in series were verified with the TCAD mixed-mode simulation results.

In this paper we developed density measurement equipment for Asphalt Pavement based on the electromagnetic capacitance. This kind of Non-Nuclear Density Gauges technology and products is used or studied in USA, Finland, Sweden as standardization of authorized method for pavement density measurement. Effective permitivity of pavement asphalt is characterized in electromagnetic capacitance by the asphalt material, mixed ratio, and harden grade of pavement asphalt. We can get a density value of asphalt by replacing value of electromagnetic capacitance with standard density value and characteristic transformation curve. We are conformed that measurement data according to temperature, humidity, and real field asphalt of our density measurement equipment can be a precise value.

In the paper, a proposed VCO based on bondwire inductances and nMOS varactors was implemented in a standard CMOS process. Using the new drain current model and a propagation delay time model equations, the operation speed of CMOS gate will predict the dependence on the load capacitance and the depth of oxide, threshold voltage, the supply voltage, the channel length. This paper describes the result of simulation which calculated a gate propagation delay time by using new drain current model and a propagation delay time model. At the result, When the reverse bias voltage on the substrate changes from 0 voltage to 3 voltage, the propagation delay time is appeared the delay from 0.8 nsec to 1 nsec. When the reverse voltage is biased on the substrate, for reducing the speed delay time, a supply voltage has to reduce. The value of MOSFET is calculated by using new drain current model.

This paper presents the development of a collocated capacitance sensor and its application to the controller design for magnetic bearing supported rotor systems. The main feature of the sensor is that it is made of a compact printed circuit board(PCB) so that it can be built into the actuator coil of the magnetic bearing unit. The singnal processing unit hax been also developed. The experi- mental results of the sensor performance evaluation on sensitivity, bandwidth and resolution are presented. Then, simulation study shows the advantages of the collocated sensor for magnetic bearings over the nonco- llocated sensor. Finally, the experimental result on the performance of the collocated sensor based contrl- ler for a magnetic bearing rotor system is presented.

The water leak in water-cooled generator stator windings can generate the serious accidents such as insulation breakdown and it brings a generator to the unexpected sudden outage. Accordingly, it is important to diagnose the water absorption of them for the effective operation of power plant. Especially, the capacitance value which is measured for diagnosis is very small so the special diagnosis methods like stochastic theory are needed. KEPRI developed the water absorption test equipment and diagnosis technology for them. The developed diagnosis technology is applied to the real system and the results of water absorption test for stator windings are agreed to them of water leak test.

When micro holes are machined by EDM, machining characteristics of machined holes are changed according to the machining conditions. Typical machining conditions are the kind of dielectric fluids, capacitance and ultrasonic vibrations. They influence electrode wear, machining time, radial clearance and taper angle. In this paper, machined holes whose depths are 300, 500, $1000\;{\mu}m$ are observed for each machining conditions. Using deionized water as a dielectric fluid makes electrode wear small, machining time short, radial clearance large and taper angle small. High capacitance makes electrode wear high. Ultrasonic vibrations make electrode wear large, machining time short, radial clearance small and taper angle small. From the results of experiments, the optimal machining conditions were obtained to machine highly qualified micro holes.

In this paper, investigated are the machining characteristics such as material removal rate and machining time with respect to discharge area and capacitance in micro electrical discharge machining (MEDM). As discharge area determined by the electrode size and capacitance change, the optimal feedrate to allow the minimum machining time changes. The smaller discharge area is, the lower MRR becomes because of the area effect. As the capacitance increases, MRR also increases. However there is the limit capacitance beyond which the MRR does not increase anymore. As the discharge area increases, the limit capacitance also increases.

The aligning between the punch and die governs no only the burr formation characteristics but also the life time of the punch and die in the sheet metal blanking process. There are many ways to adjust the two elements in the general punching systems but in the case of micro punch system, the punch size is reduced to a few tenth of micrometer range and the general aligning methods are almost impossible to apply. The image processing is the most widely used method in micro punch aligning, but in order to apply the method, it needs quite a large space for visionary system to approach the punch-die aligning zone. In this paper, the new punch-die aligning method with using the total capacitance between the punch and die hole is proposed. In this method, the tip surface of the punch tool locates at the same plane of the die surface and the capacitance variation between the two elements are measured. When the center of the two elements are coincided, the capacitance is minimized, but when the align is changed to any direction, the capacitance between the two elements increase. In order to verify the feasibility of this method, the aligning and punching tests was performed.

DC/DC 컨버터 등의 전력변환장치와 같은 비선형부하에 대해 알루미늄 전해 커패시터는 에너지의 일시적 저장이나 전압 평활용으로 많이 사용되고 있다. 그러나 전해 커패시터는 사용 시간이 늘어나면서 온도 상승 및 전해액(electrolyte)의 증발 등으로 인하여 고장이 매우 빈번하게 나타난다. 따라서 본 논문에서는 이러한 사고에 대한 고장모드를 분류하고 이를 진단하기 위한 사전 단계로 전해 커패시터의 주파수 변화에 따른 특성 해석과 이를 바탕으로 한 커패시턴스 용량 추정 알고리즘을 제안하였다. 기본파에 해당하는 저주파의 주파수 분석 결과에 따른 모의 실험의 결과는 제안한 알고리즘의 타당성을 입증하였다

Due to the large capacity and low cost, electrolytic capacitors with of energy storage and voltage regulation are used for almost all types of non-linear load as the DC/DC converter. Electrolytic capacitor, which is the most of the time affected by the aging effect, plays very important role for the power converter system quality and reliability. Therefore, this paper proposes a new method to detect the changes the capacitance value of an electrolytic capacitor in order to analyze the internal characteristic and worn-out state of an electrolytic capacitor. Simulation results by frequency analysis show the validity of the proposed capacitance estimation algorithm.

본 논문에서는 이미지 데이터를 압축하는 여러 방식 중에 YUV색 공간을 이용하여 중요도에 따라 색상 비트를 줄이는 압축 알고리즘을 제안한다. 4:2:2 서브샘플링은 영상 분야에서 표준으로 사용되고 있다. 색 정보와 사람의 망막 이 가지는 특성을 이용하여 4:2:2 서브 샘플링으로 YUV의 색상 데이터를 줄였다. YUV와 RGB는 다음과 같은 변환 행 렬을 통해 서로의 색영역으로 변환하여 사용할 수 있다. 이미지 데이터를 YUV로 색 공간으로 변환하여 상대적으로 낮 은 U , V 비트를 다운 스케일작업을 수행 한 후 수행한 후 4:2:2 서브 샘플링을 통하여 데이터를 압축한다. 기존의 방식 들과의 비교를 통하여 제안한 알고리즘의 성능을 비교하고 분석한다. 분석한 결과 중요도가 낮은 색상 요소의 정보를 줄인 결과와 원본과 비교했을 때 품질의 큰 저하 없이 이미지를 압축 할 수 있었다.

In this paper, we propose a compression algorithm that reduces color bits according to importance by using YUV color space among various methods of compressing image data. 4: 2: 2 subsampling is the standard in the field of video. By using the color information and the characteristics of the human retina, YUV color data was reduced by 4: 2: 2 subsampling. YUV and RGB can be converted to each other by using the following transformation matrix. The image data is converted into color space by YUV, and the relatively low U and V bits are subjected to the downscaling operation, and then the data is compressed through 4: 2: 2 subsampling. The performance of the proposed algorithm is compared and analyzed through comparison with existing methods. As a result of the analysis, it was possible to compress the image without reducing the information of the low importance color element and without a significant deterioration in the quality compared with the original.

In this paper, we have designed an energy efficient wrist watch on 28nm FPGA. The code has been implemented in Xilinx ISE Design Suite 14.2. The device used is XC7K160T, package used is FBG676 and it is working on -3 speed grade. The wrist band will take the blood pressure as input and will tell about the state of the person wearing it. The design supports Internet of things service that’s why IP addresses are involved. This wrist band design is very helpful in biomedical areas. Research is in progress in this field. In this paper frequency is varied to obtain power consumption of Wrist Watch. Airflow has been kept 250 LFM and medium Heat sink. IO Standards has been varied in order to achieve an energy efficient device. Main emphasis has been done on MOBILE_DDR, LVTTL, HSUL_12, HSTL_I, LVCMOS33 and SSTL15 IO Standards. To design an energy efficient device we are using capacitance scaling and the capacitance is scaled down from 100pF to 20pF. During capacitance scaling, we observe that there is no change in clock power, logic power and signal power. Thermal Aware design is current research area. Analysis has been at two temperatures that is at 25 degree Celsius and at 50 degree Celsius. At the end we can conclude that the maximum power is consumed at 2.2GHz and minimum power is consumed at 1.2GHz. In respect of capacitance maximum power is consumed at 100pF and minimum power is consumed at 20pF at both temperatures at 25 degree Celsius and 50 degree Celsius.

In this paper we focused on mathematical formulation for capacitive pressure sensor. The most important parameter of every sensor are deflection on the application of applied pressure, variation of capacitance on deflection and sensitivity. Here we mathematically drive equation for every parameter. This article help researcher to develop MEMS based capacitive pressure sensor for particular application. For that purpose we also vary the thickness of sensing diaphragm. Our study in this article is mainly consider only case of pressure sensor in normal mode. Mostly researcher use FEM method for design and simulation of capacitive pressure sensor but using these equation they can easily design any sensor by changing the parameter of equation. The material for diaphragm is Si and for insulation layer is SiO₂ is taken in this article.

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 ㎛ 두께 삼차원 구조의 LTCC 다이어프램은 NEG사의 MLS 22C 상용 파우더를 이용하여 100 ㎛ 두께의 그린쉬트를 적층하고 동시소결하여 제작하였다. 제작한 다이어프램은 공동의 면적에 따른 센싱특성을 평가하기 위하여 각각 25, 49 mm2의 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.

In this study, capacitive type pressure sensors based on low temperature co-fired ceramics (LTCC) technology for environmental monitoring were demonstrated. The LTCC is one of promising technology than si based one since it has many advantages (e.g., low cost production, high manufacturing yields and easy realizing 3D structure etc.) for sensor application. Especially, it has good mechanical and chemical properties for robust environmental application. The 3D LTCC diaphragm with thickness of 400 ㎛ were fabricated by laminating 4 green sheets using commercial powder (NEG, MLS 22C). To evaluate the sensing properties of the different cavity areas, two types of diaphragm which had different cavity areas with 25, 49 mm2 respectively, were fabricated. To realize capacitive type pressure sensor, the Au top electrode was fabricated using thermal evaporator and the bottome electrode was compressed using aluminium foil. The sensing properties of the fabricated sensors showed linear characteristic under different pressure (0~30 psi) using pressure measurement system.

Malayalam is Kerala's official language, south-western region of India mainly speak this language, and very less research has been done for designing Malayalam Unicode reader. The Unicode range of characters for Malayalam script is 0D00–0D7F. In this work, we are focusing on the script of Malayalam language and its Unicode required for coding in Hardware Descriptive Language. This paper covers the hardware design and implementation of Malayalam Unicode Reader (MUR) for Kairali scripts on Virtex-6 FPGA. This MUR design was tested with the device operating at frequency of 1THz, Capacitance has been varied from 1pF to 25pF with SSTL family (Stub Series Terminated Logic) with an interval of 5pf.

Electrical capacitance tomography (ECT) is an effective technique for visualizing the distribution of dielectric materials inside a closed pipe or vessel. The design of an ECT system based on LabVIEW is described in this paper. The system can be divided into three parts: sensor system, data acquisition system, and imaging computer. The data acquisition system designed takes C8051F700 MCU as the core to acquire capacitance data. The computer implements the functions such as data processing, image reconstruction, image display and system control. Serial communication is used between the data acquisition system and the computer. LabVIEW, a graphical programming language, is chosen as the development environment. An optimal thresholding scheme is proposed which can reduce low grey-level artifacts effectively. Equipped with a classic ECT sensor or a direct 3D ECT sensor, the system designed can work in 2D reconstruction mode or direct 3D reconstruction mode. The software design in LabVIEW is focused on.

This study considers the effect of anode capacitance as a mechanism to affect power and power quality from an MFC. A tubular MFC with a mixed culture biofilm on carbon veil electrode with a relatively high surface area was implemented. The influence of external loads (100, 500, 1k, 3k Ω) and switched open and closed circuit cycles on charge and energy were compared to the steady state load conditions. Furthermore, automated periodic discontinuous operation with short open and closed circuit cycles was applied (R = 100 Ω) and resulted in an increase in average power and current with prolonged open circuit and decreasing closed circuit periods. The capacitance effect was investigated by Electrochemical Impedance Spectroscopy (EIS) which resulted in a more than 10-fold higher double layer capacitance of the Helmholtz layer compared to the biofilm, as well as by dynamic step response of the anode and cathode potentials and their interaction during discontinuous operation. The results indicate that the capacitive behavior can be utilized to increase the power-quality, i.e. its availability/applicability with respect to the operation of low power consuming devices, however only at the expense of energy efficiency.

On the basis of analyzing the working principle of ECT data acquisition system and wavelet Kalman algorithm, the realization method of a new ECT data acquisition filter is proposed about the acquisition accuracy and real-time requirement of electrical capacitance tomography ECT (Electrical Capacitance Tomography) data acquisition system. The method uses the principle of multiplexing and folding structure to make the multi wavelet decomposition and reconstruction combined, parallelize high-pass filter and low-pass filter to meet the requirement of real-time. The simulation experiment results show that the processing speed of the improved ECT data acquisition filter is improved, the acquisition speed and the accuracy of the data are better than the traditional ECT data acquisition system, it provides a new filter realization method for ECT data acquisition system.