• Korean Journal of Remote Sensing
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• v.35 no.3
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• pp.389-400
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• 2019

Level meters are non-invasively capable of measuring the level of the medium, and a growing variety of level meters are being used in the industry in connection with safety and maintenance. The level meter can be measured according to various kinds of medium such as solid medium such as coal, flour, rice and liquid medium such as water and petroleum. In order to reduce the error depending on the medium, the measurement using the Doppler Effect can compensate the measurement error, However, the number of signal processing steps is increased, the operation speed is further increased, the hardware complexity increases, and a high cost structure is required. In this paper, we propose a method to improve the signal processing operation structure of the remote measurement level meter to reduce the amount of computation and the resource usage of the required FPGA.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.1
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• pp.81-88
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• 2003

For driver's convenience, the ACC(Adaptive Cruise Control) requires a system which determines the direction of vehicles and controls the vehicle to keep the distance among the automobiles constant. This paper describes the microstrip array antennas designed to operate at 24 GHz, and used as a direction indicator of moving vehicles. 8${\times}$2 transmit array antenna with wide beamwidth, 8${\times}$4 receive center array antenna, and two 8${\times}$8 receive array antennas with narrow beamwidth were designed and fabricated. Measurement results for the arrays showed that the azimuthal beamwidth is 50$^{\circ}$and the gain is 16.7 dBi for the transmit array antenna. For the receive array antenna, the center, the left, and the right array antenna have beamwidths of 20$^{\circ}$, 13$^{\circ}$, 13$^{\circ}$respectively, and have gains of more than 20 dBi. The left and right array antenna have the beam tilt angle of ${\pm}$18$^{\circ}$. The measured radiation patterns showed a good agreement with the simulated patterns, and the designed array antennas are suitable fur detecting 3 directions of the vehicle within the scan angle area.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.9
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• pp.854-864
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• 2016

The use of small drone platform has become a popular topic in these days but its application for SAR operation has been little known due to the burden of the payload implementation. Drone platforms are distinguished from the conventional UAV system by the increased vulnerability to the turbulences, control-errors and poor motion stability. Consequently, sophisticated motion compensation may be required to guarantee the successful acquisition of high quality SAR imagery. Extremely limited power and mass budgets may prevent the use of additional hardwares for motion compensation and the difficulty of SAR focusing is further aggravated. In this paper, we have carried out a feasibility study of mico-SAR drone operation. We present the image acquisition results from the preliminary flight tests and a quality assessment is followed on the experimental SAR images. The in-flight motion errors derived from the unique drone movements are investigated and attempts have been made to compensate for the geometrical and phase errors caused by motions against the nominal trajectory. Finally, the successful operation of drone SAR system is validated through the focussed SAR images taken over test sites.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.3
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• pp.399-405
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• 2011

In this paper, we present the design of Q-band LC VCO and injection locking buffer for 77 GHz automotive radar sensor using 130 nm RF CMOS process. To improve the phase noise characteristic of LC tank, the transmission line is used. The negative resistance by the active device cross-coupled pair of buffer is used for high output power, with or without oscillation of buffer. The measured phase noise is -102 dBc/Hz at 1 MHz offset frequency and tuning range is 34.53~35.07 GHz. The output power is higher than 4.1 dBm over entire tuning range. The fabricated chip size is $510{\times}130\;um^2$. The power consumption of LC VCO is 10.8 mW and injection locking buffer is 50.4 mW from 1.2 V supply.

• Journal of Applied Biological Chemistry
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• v.65 no.3
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• pp.143-152
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• 2022

We investigated the serum cholesterol and visceral fat lowering effects of Momordica charanatia (MC) and Withania somnifera (WS) extracts in high-fat diet (HFD)-fed mice. Combination of fermented MC and WS extracts (FMCWS) as well as that of non-fermented extracts (MCWS) were orally administered to HFD-induced obese mice along with the HFD supplementation for 8 weeks. During the experiment, body weight, food intake, and levels of total cholesterol, triglyceride and HDL-cholesterol were analyzed. Body weight and the levels of total cholesterol and triglycerides were significantly increased in the HFD-fed mice compared with the normal control (NC) group. However, supplementation of the extracts showed a tendency to reduce body weight gain and suppressed the levels of total cholesterol and triglyceride with the increment of HDL-cholesterol levels. Abdominal fat weight was significantly increased in the HFD group, and the size of adipocytes within the epididymal adipose tissue was markedly expanded compared with the NC group. However, in the FMCWS and MCWS groups, the abdominal fat weight was significantly reduced and the sizes of the adipocytes were noticeably diminished compared with those of the HFD-fed mice. Moreover, the deposition of giant vesicular fat cells observed in the liver tissue of the HFD group was prominently reduced in these groups. These results indicate that the combination of extracts from MC and WS tends to have potent synergic effects in reducing body weight gain as well as significantly lowering the visceral fat and the serum lipid levels, and thus improving anti-obesity efficacy in HFD-induced obese mice.