• Journal of Biomedical Engineering Research
• /
• v.22 no.3
• /
• pp.285-291
• /
• 2001

In this paper, we designed two preprocessing adaptive filter - high pass filter and notch filter - using FPGA. For minimizing the calculation load of multi-channel and high-resolution ECG system, we utilize FPGA rather than digital signal processing chip. To implement the designed filters in FPGA, we utilize FPGA design tool(Altera corporation, MAX-PLUS II) and CSE database as test data. In order to evaluate the performance in terms of processing time, we compared the designed filters with the digital filters implemented by ADSP21061(Analog Devices). As a result, the filters implemented by FPGA showed better performance than the filters based on ADSP21061. As a consequence of examination, we conclude that FPGA is a useful solution in multi-channel and high-resolution signal processing.

• Proceedings of the IEEK Conference
• /
• 2000.11c
• /
• pp.153-156
• /
• 2000

A novel silicon retina chip based on the information processing in the vertebrate retina was designed. The chip has a novel wiring structure in which all pixels are connected through the channel of MOS transistors, which simplifies a wiring structure compared with conventional resistive networks. The proposed structure minimizes the pixel area and certainly increases a fill factor since each pixel consists of only two photodiodes and three MOS transistors. It also enables the chip to operate over a wide range of light intensity by adjusting its conductance with the gate voltage. Simulation results with SPICE showed that the chip could extract the edge of input images successfully.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.6
• /
• pp.181-186
• /
• 2007

UBM (Under Bump Metallurgy) of flip chip assemblies consists of several layers such as the solder wetting, the diffusion barrier, and the adhesion layers. In addition, IMC layers are formed between the solder wetting layers (e.g. Cu, Ni) and the solder. The primary failure mechanism of the solder joints in flip chips is widely known as the fatigue failure caused by thermal fatigues or electromigration damages. Sometimes, the premature brittle failure occurs in the IMC layers. However, these phenomena have thus far been viewed from only experimental investigations. In this sense, this paper presents a method for solid modeling of IMC layers in flip chip assemblies, thus providing a pre-processing tool for finite element analysis to simulate the IMC failure mechanism. The proposed modeling method is CSG-based and can also be applied to the modeling of UBM structure in flip chip assemblies. This is done by performing Boolean operations according to the actual sequences of fabrication processes

• Transactions of Materials Processing
• /
• v.20 no.1
• /
• pp.17-22
• /
• 2011

Recently, analyzing system is studying for applying to biomedical engineering field, actively. Micro fluidics control system has been manufactured using LIGA (Lithographie Galvanoformung und Abformung), Etching, Lithography and Laser etc. However, it is difficult that above-mentioned methods are applied to fabrication of precision mold master efficiently because of long processing time and rising cost of equipments. Therefore, in this study, micro EDM and micro WEDG system were developed to analyze machining characteristics with tool wear, surface roughness and process time. Then, optimal machining conditions could be obtained from the results of analysis. As the results, mold master of staggered herringbone mixer which has a high mixing efficiency, one of passive mixer of Lab-on-a-chip, could be fabricated from micro pattern(< 50um) using micro EDM successfully.

• Journal of the Institute of Convergence Signal Processing
• /
• v.1 no.1
• /
• pp.89-96
• /
• 2000

In this paper, we propose a vision algorithm for the inspection of very small RF-chip inductor which is used in mobile-communication terminal. The proposed method divides coil part from the inductor body by local adaptive thresholding and integral projection method. After dividing work, the coil components are extracted by thinning and labelling techniques. The test items are the number of turns, the intervals in coil, and the measure of uniformity between the extracted lines. If the values of these are more than the specific value a tested product is decided bad one. In the simulation, the proposed method has a good performance.

• Journal of Information Processing Systems
• /
• v.17 no.1
• /
• pp.191-202
• /
• 2021

In an Internet of Things (IoT)-configured system, each device executes on-chip software. Recent IoT devices require fast execution time of complex services, such as analyzing a large amount of data, while maintaining low-power computation. As service complexity increases, the service requires high-performance computing and more space for embedded space. However, the low performance of IoT edge devices and their small memory size can hinder the complex and diverse operations of IoT services. In this paper, we propose a remote on-demand software code execution unit using the cloudification of on-chip code memory to accelerate the program execution of an IoT edge device with a low-performance processor. We propose a simulation approach to distribute remote code executed on the server side and on the edge side according to the program's computational and communicational needs. Our on-demand remote code execution unit simulation platform, which includes an instruction set simulator based on 16-bit ARM Thumb instruction set architecture, successfully emulates the architectural behavior of on-chip flash memory, enabling embedded devices to accelerate and execute software using remote execution code in the IoT environment.

• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.1153-1156
• /
• 1998

We describe a design of a simple but efficient floatingpoint processing architecture expoiting concurrent execution of scalar instructions for high performance in general-purpose microprocessors. This architecture employs 3 stage pipeline asyncronously working with integer processing unit to regulate instruction flows between two arithmetic units.

• Journal of Adhesion and Interface
• /
• v.13 no.2
• /
• pp.58-63
• /
• 2012

CFRP chip is the byproduct from carbon fiber reinforced plastic (CFRP) processing. CFRP chip is not simply a waste mainly composed of fine carbon fiber and epoxy resin. CFRP chip keeps matrix to maximize their reinforcing effect. To obtain a uniform length of carbon fiber in CFRP chip, chip was chopped ina mortar. CFRP chip should be purified to get better interface adhesion. Epoxy resin on the carbon fiber was removed by $H_2O_2$ surface etching treatment. Optimal dispersion and fabrication conditions of CFRP chip embedded in phenolic resin were determined by thermal stability for fire retardant applications. CFRP chip-phenolic composite exhibits better mechanical and thermal properties than neat phenolic resin. Surface condition of CFRP chip-phenolic composite was evaluated by static contact angle measurement. Contact angle of CFRP chip-phenolic composite was greater than neat phenolic due to heterogeneous condition of fine carbon fibers. From the evaluation for fire retardant (ASTM D635-06) test, thermal stability of CFRP chip-phenolic composite was found to be improved with higher concentration of CFRP chip.

• International Journal of Precision Engineering and Manufacturing
• /
• v.8 no.1
• /
• pp.11-15
• /
• 2007

Composite materials are widely used to make all kinds of machine parts, internal and structural materials of cars, aerospace components, building structures, ship materials, sporting goods and others, It is worth while to use composite space substitute material in various applications when compared with others. But the use of composite material is limited in the field of the mechanical processing because of the difficulties in processing. Thus, it is proved that the surface is rough at the in and out sections of the hole processing when the GFRP is machined with HSS drill in the vertical machining center. And it is observed that the more it is processed, the more the fluid type long chip is changed into the powdered chip.

• Food Science and Biotechnology
• /
• v.16 no.6
• /
• pp.889-893
• /
• 2007

The demand of quality green banana chips is increasing in the world snacks market, therefore, the preparation of quality chips and their subsequent shelf life in packaging were evaluated in this study. Banana slices were fried in hot oil to the desired moisture content (2-3%) and oil content (40%) in chips at 3 different temperatures, and the impact of different pretreatments were compared by sensory assessment. A linear relationship between time and temperature was used to achieve the optimal processing conditions. Banana slices fried at the lower temperature of $145^{\circ}C$ took longer to reach the desired chip qualities, but gave the best results in terms of color and texture. Blanching was the most effective pre-treatment for retaining the light yellow color in finished chips. For extending the shelf life of chips, moisture proof packaging in double layer high density polyethylene was more effective than single layer low density polyethylene.