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.

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.

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.

Synchronized switch damping (SSD) techniques have recently been developed, as an alternative to active vibration control techniques, to address the problem of structure vibration control. In these techniques, a piezoelectric patch is bonded on the vibrating structure and shunted by a network of electrical elements. During the structure motion, the piezoelectric patch is connected and disconnected from the shunt circuit, according to the displacement extremum, through switching action controlled by a digital signal processing system. Thus the voltage in the piezoelectric patch is enhanced and time shifted in the time domain from the displacement of the vibrating structure. This voltage when shunted through electrical circuit results in increased energy dissipation with enhanced damping effect. This paper proposes to further increase the dissipated energy through a new technique called the synchronized switch damping on negative capacitance and voltage sources (SSDNCV). The idea is to further increase the value of voltage in the piezoelectric patch though the use of negative capacitance and two extra voltage sources in the shunt circuit. First theoretical expressions are derived for SSDNCV method to determine the maximum energy dissipated from the shunt circuit and the corresponding maximum damping. The effectiveness of SSDNCV method, as compared to the previous SSD methods, is then demonstrated in the first resonance mode control of a cantilever beam containing piezoelectric patch. The SSDNCV control reduced the vibration amplitude by 82 % as compared to 63 % and 29 % obtained from SSDNCI and SSDV controls respectively.

Sensitivity field distribution of the sensor in ECT system is affected by the distribution of the mixture, The "soft field" property of sensitive field bring great difficulty in image reconstruction, on the basis of analyzing capacitance tomography sensitive mechanism, by analyzing that sensor structure parameters in ECT system have influence on the uniformity of the sensitive field, this paper proposed a structural parameters optimization algorithm based on the ant colony algorithm. The algorithm first determines the parameter optimization design evaluation function, and then rapidly identifies several suboptimal paths by using particle swarm optimization and initializes the pheromones in the path, Ant colony algorithm finds the optimal solution according to the initialization pheromones and using the characteristics of rapid convergence. The experimental results show that, compared with the orthogonal algorithm, the performance of the sensor designed by using the structure parameters obtained by ant colony optimization algorithm is obviously improved, Alleviate the difficulty of data acquisition circuit design and improve the accuracy and uniformity of the sensitive field, the quality of image reconstruction is improved, the relative error of image reconstruction is reduced.

"Soft-field" nature and ill-posed problems to influence on the accuracy of image reconstruction in electrical capacitance tomography technology (ECT), in the analysis of ECT basic principle and imaging algorithm, a novel image fusion method based on edge feature detection using the feature of different frequency domains of wavelet decomposition is presented in this paper. The LBP algorithm and Landweber algorithm are used as the base of image reconstruction in the paper, the fusion rules based on the combination of Local gradient and local signal strength and the weighted averaging operator are used to fuse the high-frequency coefficients and low-frequency coefficients of the fused image, in this way , higher accuracy imaging results can be got. The simulation results show that the image fusion accuracy is improved, and reconstruction image effect is enhanced.

According to the image reconstruction accuracy influenced by the “soft field” nature and the limited projection data in electrical capacitance tomography, based on the working principle of the electrical capacitance tomography system, a Novel image reconstruction algorithm based on compressed sensing is proposed in the paper. The method based on ART (algebra reconstruction technique) organically combines the gradient sparse of image and ART, and reduces the norm of image gradient with full-variational method, and improves the accuracy and speed of image reconstruction. Experimental results and simulation data indicate that the imaging accuracy is markedly improved, and the image is closed to the prototype. This new algorithm presents a feasible and effective way to research on image reconstruction algorithm for Electrical Capacitance Tomography System.

To solve the "soft field" effect and the ill-posed problem in electrical capacitance tomography technology, a novel image reconstruction algorithm based on population entropy and adaptive differential evolution for Electrical Capacitance Tomography is proposed in this study. The algorithm uses all the gray pixels as the initial population’s individual. After finite iterations, the algorithm mutates and makes crossover of the population in order to obtain the optimal species populations. That is the optimal value for the ECT imaging pixels. The population entropy and the variation factor make the range of each searching generation decreasing. In the simulation, the improved adaptive differential evolution algorithm will be compared with the LBP algorithm. The result shows that the new algorithm has better image quality and more stable boundary than the LBP Algorithm, which provides a new way to reconstruct images for ECT.

This paper presents a design and implement method of battery management system about emergency light based on loose capacitance synchronous sampling measure technology and balanced technology. Through the real-time data acquisition, charge and discharge control, the low voltage detection and protection mechanisms of the system, the system achieves protecting the battery pack of emergency light successfully, collecting data accurately and processing the collected data.

나노입자를 이용하여 강화 효과를 높이기 위해서는 고분자 기지 내부의 균일한 분산 상태를 확보하여야 한다. 또한 균일분산 조건 확보 후 균일 분산상태를 증명할 평가자료가 필요하다. 본 연구는 에폭시 수지와 SiC 나노입자를 혼합한 SiC/에폭시 복합 수지를 제조할 경우 커패시턴스 측정법을 이용한 강화재 분산도 예측 연구를 진행하였다. 커패시턴스는 전기용량을 의미하며 측정 재료의 내부 전하량과 비례한다. 기존 에폭시 수지에 비해 나노 SiC 입자를 함유할 경우 전하량이 증가되는 이론을 바탕으로 구간별 커패시턴스 측정에 따른 분산도 평가를 진행하고, 커패시턴스 분산도 예측방법에 대한 타당성을 FE-SEM과 물리적 강도 증가 방법으로 평가하였다. 소니케이션 분산 방법과 교반기 분산 방법을 이용하여 분산 방법에 따른 SiC 나노입자 분산도 상태를 비교하였다. 인장강도와 커패시턴스 간의 상관관계가 있었으며, 파단면에 대한 비교를 할 때 분산성 향상에 대한 차이를 확인할 수 있었다.

The good dispersion of nano-materials in epoxy matrix was important parameter for the reinforcement effect, and the evaluation of dispersion degree was to prove it. This work was studied to predict the dispersion condition of nano-SiC powders in SiC/epoxy composites using capacitance measurement. Capacitance was defined to be the electric capacity in proportional to electron charge of the measuring section. In case of nano-SiC powders, the electron charge of SiC/epoxy composites was higher than that of neat epoxy resin. Capacitance was evaluated for each section of SiC/epoxy composites. The prediction of dispersion condition was verified by using capacitance measurement. Dispersion condition of nano-SiC powders in epoxy matrix was evaluated with two different dispersion methods, i.e., sonication and stirring methods. The dispersion degree was also verified with the tensile strength correlating to capacitance.