• Journal of Sensor Science and Technology
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• v.27 no.5
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• pp.311-316
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• 2018

An antenna-coupled bolometer-type terahertz sensor was designed, fabricated, evaluated, and utilized to obtain terahertz transmission images. The sensor consists of a thin film bowtie antenna that resonates accordingly in response to an incident terahertz beam, a heater that converts the applied current in the antenna into heat, and a microbolometer that converts the rise in temperature into a change in resistance. The device is fabricated by a bulk micromachining process on a 4-inch silicon wafer. The fabricated sensor chip has a size of $2{\times}2mm$ and an active area of $0.1{\times}0.1mm^2$. The temperature coefficient of resistance (TCR) of the bolometer film (VOx) is 2.0%, which is acceptable for bolometer applications. The output sensor signal is proportional to the power of the incident terahertz beam. Transmission images were obtained with a 2-axis scanning imaging system that contained the sensor. The small active area of the sensor will enable the development of highly sensitive focal plane array sensors in terahertz imaging cameras in the future.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.7
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• pp.65-75
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• 2011

As the technology of SoC design has been developed, the debugging is more and more important and users want a fast and reliable debugger. This paper deals with an implementation of the fast debugger which can reduce a debugging processing cycle by designing a modified JTAG suitable for a new RISC processor debugger. Designed JTAG is embedded to the OCD of Core-A and works with SW debugger. We confirmed the functions and reliability of the debugger. By comparing to the original JTAG system, the debugging processing cycle of the proposed JTAG is reduced at 8.5~72.2% by each debugging function. Further more, the gate count is reduced at 31.8%.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.12
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• pp.61-68
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• 2004

Wireless mobile communication systems request high speed mobility and high speed data transmission capability. In order to meet the requirements, OFDM(Orthogonal Frequency Division Multiplex) is mainly adopted in the physical layer of the wireless systems. In commercial wireless mobile systems, IEEE802.(11a, 16e, etc) series seem to be used as the modulation method. For supporting multiple air-interfaces in a wireless mobile system, different kinds of OFDM based modulation methods should be supported in one modem chip. It requires a variable point IFFT/FFT or reconfigurable IFFT/FFT processor. In this paper, we propose the design method of a reconfigurable IFFT/FFT processor. In addition, it is shown that a reconfigurable IFFT/FFT processor can he implemented by using the proposed method.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5513-5518
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• 2013

IFN-${\gamma}$ plays an indirect anti-cancer role through the immune system but may have direct negative effects on cancer cells. It regulates the viability of gastric cancer cells, so we examined whether it affects their proliferation and how that might be brought about. We exposed AGS, HGC-27 and GES-1 gastric cancer cell lines to IFN-${\gamma}$ and found significantly reduced colony formation ability. Flow cytometry revealed no effect of IFN-${\gamma}$ on apoptosis of cell lines and no effect on cell aging as assessed by ${\beta}$-gal staining. Microarray assay revealed that IFN-${\gamma}$ changed the mRNA expression of genes related to the cell cycle and cell proliferation and migration, as well as chemokines and chemokine receptors, and immunity-related genes. Finally, flow cytometry revealed that IFN-${\gamma}$ arrested the cells in the G1/S phase. IFN-${\gamma}$ may slow proliferation of some gastric cancer cells by affecting the cell cycle to play a negative role in the development of gastric cancer.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1797-1806
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• 1998

Future satellite communication systems will be developed at Ka-band (20/30 GHz) owing to the relatively wide frequency allocation and current freedom from terrestrial interference for multimedia services. A serious disadvantage of the Ka-band, however, is the very high atmospheric attenuation in rainy weather. Synchronous CDMA drastically redces the effect of self-noise with several interesting features of CDMA for mobile communications such as fixible freuqncy rese, the capability of performin soft-handover and a lower sensitivity to interference. This paper evaluates the performance of a synchronous CDMA reture link for a Ka-band geostationary satellite communication system. For a fixed satellite channel whose characteristics depend on weather conditions, the signal envelope and phase for this channel is modelled as Gaussian. The bit error and outage probability, and the detection loss due to imperfect chip timing synchronization is analytically evaluated and the system capacity degaradation due to the weather condition is estimated. The two cases consist of the general case in which all users are affected by rain condition, and the worst case in which the reference user is only affected by rain attenuation. the results for two cases of rain condition clearly show that synchronous CDMA eases the power control requirements and has less sensitivity to imperfect power control.

• Journal of Korea Foresty Energy
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• v.24 no.2
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• pp.1-9
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• 2005

After manufacturing fermentation system for degrading pig manure using environmentally friendly technique, performance of the system and characteristics of wood chips and pig manure fermented in the system were analyzed. Results from this study shows that proper fermentation temperature($55{\sim}60^{\circ}C$) reached 3days after the system started and degradation rate, which expresses fermentation performance of system, was $180{\iota}$/day. Even as progressing the fermentation of wood chips and pig manure mixture, the amount of extractives drawn out by alkali, and alcohol-benzene and lignin content was not varied. However, ash content in wood was increased. The inorganic compounds in pig manure seem to be transferred into wood chip. On the other hand holocellulose contents in wood were decreased a little. Holocellulose seems to be consumed as the second carbon source in fermentation process. Results through analysis of inorganic- and heavy metal elements contents in wood chips and pig manure fermented in long term process shows that inorganic elements($Ca^{2+},\;Mg^{2+},\;K^+,\;Na^+$ etc.) contents were increased with fermentation time and heavy metal elements(Cd, As, Cu etc.) which cause environmental pollution were not detected. Number of microorganisms including bacteria, actinomycetes, and fungi, the number of C.F.U(Colony Forming Unit) was increased while temperature in fermentation system was abruptly increased.

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1968-1976
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• 2006

Recombinant E. coli ACV 1003 (recA:: lacZ) was used to measure low concentrations of DNA-damaging chemicals, which produce $\beta$-galactosidase via an SOS regulon system. Very low $\beta$-galactosidase activities of less than 0.01 unit/ml, $\beta$-galactosidase produced through an SOS response corresponding to the 10 ng/ml (ppb) of DNA damaging chemicals in the environment, can be rapidly determined by using an alternative interferometric biosensor with optically flat thin films of porous silicon rather than by the conventional time-consuming Miller's enzyme assay as well as the ELISA method. fu order to enhance the sensitivity in the interferometry, it needs to obtain more uniform distribution and higher biolinking efficiency, whereas interferometric sensing is rapid, cheap, and advantageous in high throughput by using a multiple-well-type chip. In this study, pore size adjusted to 60 nm for the target enzyme $\beta$-galactosidase to be bound on both walls of a Si pore and a calyx crown derivative was apllied as a more efficient biolinker. Furthermore, anti-$\beta$-galactosidase was previously functionalized with the biolinker for the target $\beta$-galactosidase to be specifically bound. When anti-$\beta$-galactosidase was bound to the calyx-crown derivative-linked surface, the effective optical thickness was found to be three times as high as that obtained without using anti-$\beta$-galactosidase. The resolution obtained was very similar to that afforded by the time-consuming ELISA method; however, the reproducibility was still unsatisfactory, below 1 unit $\beta$-galactosidase/ml, owing to the microscopic non-uniform distribution of the pores in the etched silicon surface.

• Journal of Powder Materials
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• v.20 no.5
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• pp.355-358
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• 2013

Micro trench structures are applied in gratings, security films, wave guides, and micro fluidics. These micro trench structures have commonly been fabricated by micro electro mechanical system (MEMS) process. However, if the micro trench structures are machined using a diamond tool on large area plate, the resulting process is the most effective manufacturing method for products with high quality surfaces and outstanding optical characteristics. A nonferrous metal has been used as a workpiece; recently, and hybrid materials, including polymer materials, have been applied to mold for display fields. Thus, the machining characteristics of polymer materials should be analyzed. In this study, machining characteristics were compared between nonferrous metals and polymer materials using single crystal diamond (SCD) tools; the use of such materials is increasing in machining applications. The experiment was conducted using a square type diamond tool and a shaper machine tool with cutting depths of 2, 4, 6 and 10 ${\mu}m$ and a cutting speed of 200 mm/s. The machined surfaces, chip, and cutting force were compared through the experiment.

• Information and Communications Magazine
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• v.9 no.9
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• pp.72-85
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• 1992

The throughput requirement for many digital signal processing is such that multiple processing units are essential for real-time implementation. Advances in VLSI technology make it feasible to design and implement computer systems consisting of a large number of function units. The research on a very high throughput VLSI architecture for digital signal processing applications requires the development of an algorithm, decomposition scheme which can minimize data communication requirements as well as minimize computational complexity. The objectives of the research are to investigate computationally efficient algorithms for solution of the class of problems which can be modeled as DLSI systems or adaptive system, and develop VLSI architectures and associated multiprocessor systems which can be used to implement these algorithms in real-time. A new VLSI architecture for real-time 2-D digital signal processing applications is proposed in this research. This VLSI architecture extends the concept of having a single processing units in a chip. Because this VLSI architecture has the advantage that the complexity and the number of computations per input does not increase as the size of the input data in increased, it can process very large 2-D date in near real-time.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.1
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• pp.62-74
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• 2008

In this paper, we would like to propose the design of symmetric digital filter core in order to use in the radio astronomy. The function of FIR filter core would be designed by VHDL code required at the Data Acquisition System (DAS) of Korean VLBI Network (KVN) based on the FPGA chip of Vertex-4 SX55 model of Xilinx company. The designed digital filter has the symmetric structure to increase the effectiveness of system by sharing the digital filter coefficient. The SFFU(Symmetric FIR Filter Unit) use the parallel processing method to perform the data processing efficiently by using the constrained system clock. In this paper, therefore, for the effective design of SFFU, the Unified Synthesis software ISE Foundation and Core Generator which has excellent GUI environment were used to overall IP core synthesis and experiments. Through the synthesis results of digital filter core, we verified the resource usage is less than 40% such as Slice LUT and achieved the maximum operation frequency is more than 260MHz. We also confirmed the SFFU would be well operated without error according to the SFFU simulation result using the Modelsim 6.1a of Mentor Graphics Company. To verify the function of SFFU, we carried out the additional simulation experiments using the pseudo signal to the Matlab software. From the comparison experimental results of simulation and the designed digital FIR filter, we confirmed the FIR filter was well performed with filter's basic function. So we verified the effectiveness of the designed FIR digital filter with symmetric structure using FPGA and VHDL.