• 전자공학회논문지A
• /
• 제33A권11호
• /
• pp.140-151
• /
• 1996

In this study, we designed the routing structure and logic block of a SRAM cell-based FPGA with symmetrical-array architecture. The designed routing structure is composed of switch matrices, routing channels and I/O blocks, and the routing channels can be subdivided into single length channels, double length channels and global length channels. The interconnection between wires is made through SRAM cell-controlled pass transistors. To reduce the signal delay in pass transistors, we proposed a scheme raising the gate-control voltage to 7V. The designed SRAM cells have built-in shift register capability, so there is no need for separate shift registers. We designed SRAM cells in the LUTs(look-up tables) to enable the wirte operations to be performed synchronously with the clock for ease of system application. Each logic block (LFU) has four 4-input LUTs, flip-flops and other gates, and the LUTs can be used a sSRAM memory. The LFU also has a dedicated carry logic, so a 4-bit adder can be implemented in one LFU. We designed our FPGA using 0.6.mu.m CMOS technology, and simulation shows proper operation of a 4 bit counter at 100MHz.

• 한국임상수의학회지
• /
• 제4권2호
• /
• pp.463-472
• /
• 1987

Although there are many reports on the bovine electroacupuncture anesthesia, its application to clinical cases needs much to be verified. In order to apply the electroacupuncture anesthesia to bovine species, a new anesthesia technique, which is safe and effective, must be developed. In the present study, 11 meridian points were selected and 11 kinds of meridian points were prescribed to develop an effective and safe electroacupucture methods in the bovine species. The results obtained are summarized as fellows : 1. When the maximun electric current (30Hz at 5.3-5.6V ) was applied, anesthesia was attained with the signs of tetany and tremor : When the electric current was continued for 15-20 minutes, the signs of tetany and tremor diminished markedly. 2. If the electric current was adjusted to 30Hz at 3.5-4.0V and continued, the tetany and tremor disappeared. The skin was slackened, thus suitable for surgical operation. The continuation of anesthesia could be regulated at operator's own will. 3. The same anesthesia effect could be attained by using any one meridian point when the points were symmetrical. 4. Transient changes of clinical signs and blood pictures were noted during the stages of acupuncture anesthesia. However, the red blood cell counts, white blood cell counts and hematocrit values were always within the normal range.

• 한국세라믹학회지
• /
• 제42권12호
• /
• pp.787-792
• /
• 2005

A symmetrical LSCF $(La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-\delta})\;ScSZ(89ZrO_2-10Sc_2O_3-1CeO_2)/LSCF$ electrochemical cell with a GDC (Gadolinium-Doped Ceria, $90CeO_2-10Gd_2O_3$) interlayer that was inserted between the LSCF cathode and ScSZ electrolyte was fabricated, and the electrochemical performance of these cells was evaluated. The GDC interlayer was deposited on a ScSZ electrolyte using a screen-printing technique. The GDC interlayer prevented the unfavorable solid-state reactions at the LSCF/ScSZ interfaces. The LSCF cathode on the GDC interlayer had excellent electrocatalytic performance even at $650^{\circ}C$. The Area Specific Resistance (ASR) was strongly dependent on the thickness and heat-treatment temperature of the GDC interlayer. The impedance spectra showed that the cell with a $15\~27{\mu}m$ thick GDC interlayer heat-treated at $1200^{\circ}C$ had the lowest ASR.

• Korean Membrane Journal
• /
• 제10권1호
• /
• pp.46-52
• /
• 2008

Optimization of ionomer solution was conducted in order to improve the performance of MEAs in PEMPC. The interface between membrane and electrodes in MEAs is crucial region determining fuel cell performance as well as ORR reaction at cathode. Through the modification of Nafion ionomer content at the interface between membrane and electrodes, an optimal content was obtained with Nafion 115 membranes. Two times higher current density was obtained with the outer Nafion sprayed MEA compared with the non-sprayed one. In addition, the symmetrical impedance spectroscopy mode (SM) exhibited that the resistances of membrane area, proton hydration, and charge transfer decreased as the outer Nafion is sprayed. From the polarization curves and SM, the highest current density and the lowest resistance was obtained at the outer ionomer content of $0.15\;mg\;cm^{-2}$.

• 미생물학회지
• /
• 제17권1호
• /
• pp.1-15
• /
• 1979

Mycoplasma pneumoniae strain CL-s attached to broth-covered surfaces was examined sequentially during growth from single cells for morphologic and ultrastructural changes using several different electron microscopic techniques. Changes in morphology revealed both round and spindle shapes and observation of cell transitions suggested some type of morphological cycle. The round to-ovoid cells observed in the early stages of growth appeared to be viable, and morphologically and ultrastructurally different from the spherical fors which were produced during the latter stage of growth. The spindle segments were detected appeared to be structurally the same as the terminal cored structure seen in thin sections and may be a growing point or an attachment site of the cell. A tubular structure was observed in the core of the terminal structure and a microtubule-like element appeared to bridge between some spindle segments. A matrix sunstance was observed around single cells as well in the intercellular space of the colonies prepared by critical point metrical triple-layered cytoplasmic mermbranes, surfaces, of which appeared to be structurally different each other, were observed in young cells, whereas symmetrical and thicker membranes were seen in older cells. Small bodies were found in 4d or older cultures and did not appear to contain any internal structures or an easily detectable unit membrane.

• Nuclear Medicine and Molecular Imaging
• /
• 제41권3호
• /
• pp.260-262
• /
• 2007

A 68-year-old man with small cell carcinoma of the lung and adenocarcinoma of the prostate underwent Tc-99m MDP bone scintigraphy for the evaluation of skeletal metastases. Bilateral symmetrical photon defects in both parietal bones of the skull were observed. The radiographs of the skull demonstrates biparietal thinning in the same area of the abnormality identified on bone scintigraphy. Although these findings in cancer patients can be mistaken for skeletal metastases, the symmetry and location of the photon defects are generally indicative of biparietal thinning.

• Journal of Power Electronics
• /
• 제17권5호
• /
• pp.1195-1202
• /
• 2017

This paper presents a novel topology named a modified capacitor-assisted Z-source inverter (MCA-ZSI) based on the traditional ZSI. The impedance network of the proposed MCA-ZSI consists of two symmetrical cells coupled with two capacitors with an X-shape structure, and each cell has two inductors, two capacitors, and one diode. Compared with other topologies based on switched ZSI with the same number of components used at impedance network, the proposed topology provides higher boost ability, lower voltage stress across inverter switching devices, and lower capacitor voltage stress. The improved performances of the proposed topology are demonstrated in the simulation and experimental results.

• 전자공학회논문지C
• /
• 제34C권6호
• /
• pp.28-36
• /
• 1997

In this work, a highly linear video-speed CMOS current-mode digital-to-analog converter (DAC) is proposed. A newswitching scheme for the current cell matrix of the DAC simultaneously reduces graded and symmetrical errors to improve integral nonlinearities (INL). The proposed DAC is designed to operate at any supply voltage between 3V and 5V, and minimizes the glitch energy of analog outputs with degliching circuits developed in this work. The prototype dAC was implemented in a LG 0.8um n-well single-poly double-metal CMOS technology. Experimental results show that the differential and integral nonlinearities are less than .+-. LSB and .+-.0.8LSB respectively. The DAC dissipates 75mW at a 3V single power supply and occupies a chip area of 2.4 mm * 2.9mm.

• Structural Engineering and Mechanics
• /
• 제59권5호
• /
• pp.901-920
• /
• 2016

MeshFree methods have become popular owing to the ease with which high stress gradients can be identified and node density distribution can be reformulated to accomplish faster convergence. This paper presents a strategy for nodal density refinement with strain energy as basis in Element-Free Galerkin MeshFree technique. Two popular flat plate problems are considered for the demonstration of the proposed strategies. Issue of integration errors introduced during nodal density refinement have been addressed by suggesting integration cell refinement. High stress effects around two symmetrical semi-circular notches under in-plane axial load have been addressed in the first problem. The second considers crack propagation under mode I and mode II fracture loading by the way of introducing high stress intensity through line crack. The computational efficacy of the adaptive refinement strategies proposed has been highlighted.

• International journal of advanced smart convergence
• /
• 제13권2호
• /
• pp.1-6
• /
• 2024

Reconfiguration and miniaturization of antennas have become key attributes in modern wireless communication systems. Reconfiguration of radiation pattern can alleviate the problems encountered in modern wireless communication systems such as multi-path problems. Physical limitation of miniaturization also can be overcome by using a zeroth-order resonance (ZOR) antenna based on metamaterial. In order to achieve reconfiguration and miniaturization of antennas at the same time, we propose a new pattern reconfigurable zeroth-order resonance (ZOR) antenna that reconfigures the radiation patterns by varying the position and the number of unit cells comprising the antenna. The antenna is fabricated in an equilateral triangular shaped symmetrical structure to increase pattern variety. This structure can easily provide eight different radiation patterns (two omnidirectional and six monopole like patterns).