• Journal of radiological science and technology
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• v.42 no.4
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• pp.271-277
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• 2019

CareDose 4D which is the Siemens's Automatic Exposure Control (AEC) can adjust the level of radiation dose distribution which is based on organ characteristic unlike other manufacturer's AEC. Currently, a wide scan range containing different organs is sometimes examined at once (defined as one scan). The purpose of this study was to figure out which organ characteristic option is suitable when one scan method is utilized. Two types of anthropomorphic phantoms were scanned in the same range which were from frontal bone to carina level according to three different organ characteristics such as Thorax, Abdomen, and Neck. All scans and image reconstruction parameters were equally applied and radiation dose were compared. Radiation dose with Thorax organ characteristic was lower than that with Neck. Also, that with Abdomen oran characteristic was lower than Thorax. There were significant differences in radiation dose according to different organ characteristics at the same parameters (P<0.05). Usage of Neck organ characteristic had a result of the highest radiation dose to all phantom. On the other hand, utilization of Abdomen organ characteristic showed the lowest radiation dose. As a result, it is desirable to set appropriate organ characteristic according to examined body part when you checkup patients. Also, when you implement one scan method, selection of Abdomen-based organ characteristic has reduced more radiation dose compared with two different organ characteristic.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.715-716
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• 2006

Nowadays, research of EMI/EMC is very important in electromagnetic wave surroundings generated from many electric and electronic devices. Especially, analysis of electromagnetic radiation characteristic and field have to be performed first of all. At the present most of EMI/EMC problems are solved by the method of practice and inspiration. Hence in this paper, will provide the first step for solving EMI/EMC problems in design process. Model of analysis is structure composed of PCB and Frame. By the first step, theory of dipole antenna is adapted to analyze electromagnetic radiation characteristic and field. Because it is fundamental of analysis of electromagnetic radiation. And it will be expanded for structure of PCB and Frame. Finally, it provide the basic method of analysis of electromagnetic radiation characteristic and field by making similar dipole antenna to PCB and Frame structure.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.4
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• pp.531-536
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• 2003

In order to control the railway noise. we should know the radiation characteristic of the noise during the train passage Generally, the railway noise sources for conventional trains are classified by the rolling noise and power unit noise in tangent track. In this Paper. we describe on a train model that is considered to be a row of point sources to calculate the radiation characteristic The calculation results are compared with short distance measurement of three kinds of trains (EMU, Mookungwha, Saemaul). It is shown that the radiation characteristic of the rolling noise that is major noise source of electric multiple unit is dipole type. We know that characteristic of the engine noise is radiated as the cosine type.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.11
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• pp.951-959
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• 2015

Ground radiation antenna in mobile devices is becoming an issue for satisfying both miniaturization and high performance. Ground radiation antenna controls the characteristic mode of the ground plane and couples this mode with the ground radiation antenna, thereby having good radiation performance. In this paper, the characteristic mode theory and applications of ground radiation antenna will be introduced. The operating mechanism of single band, wideband and dual-band ground radiation antennas are studied.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.811-812
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• 2007

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.379-386
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• 2018

A heat-sink has been widely used to cool down the heat generated from an electronic device, but it can bring unwanted electromagnetic radiation which may cause EMI problems. We propose a systematic method to reduce the electromagnetic radiation by using the multiple grounding technique based on the grounding criteria and the theory of characteristic mode analysis. Our proposed method provides the insight to find the specific grounding positions which can be effectively reduced the radiation from the heat-sink. Numerical experiments are accomplished to validate this approach.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.323-327
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• 2002

In order to control the railway noise, the radiation characteristic of the noise during the train passage should be analyzed. Generally, the major noise sources for Korean Train Express are the rolling noise and power unit noise up to 300km/h. In this paper, we describe on a train model that is considered to be a row of point sources to calculate the radiation characteristic. The calculation results are compared with short distance measurement. It is shown that the radiation characteristic of the rolling noise is dipole type. The noise generated by the power unit is radiated as the cosine type. The noise level at an observer is increased in the direction of motion and reduced in the direction opposite to the motion with increasing of the train speed. The calculation results including the moving effect of the noise source at 300km/h show in good agreement.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.7
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• pp.23-29
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• 1995

A characteristic mode theory for longitudinal slot of arbitrary width in the outer conductor of coaxial waveguide is applied for calculating the characteristic magnetic currents, the characteristic fields, radiation patterns, and the fields evershere(inside and outside the guide, and in the aperture region). Numerical results of the equivalent magnetic currents and the radiation patterns are compared with those obtained by use of the method of moments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.963-968
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• 2013

Ionizing Radiation effects on MOS devices provide useful information regarding the behavior of MOS based devices and circuits in the electronic instrumentation parts and instructive data for making the high sensitive sensors. The study presents the results of the analysis on the structural characteristics of MOS capacitor for sensing the ionizing radiation effect. We performed numerical modeling of Ionizing-radiation effect on MOS capacitor and simulation using Matlab program. Also we produced MOS capacitors and obtained useful data through radiation experiment to analyse the characteristic of ionizing radiation effect on MOS capacitor. Increasing the thickness of MOS capacitor's oxide layer enhanced the sensitivity of MOS capacitor under irradiation condition, but the sensitivity of irradiated MOS capacitor is uninfluenced by the area of MOS capacitor. The high frequency capacitance of the MOS capacitor is found to be strongly affected by incident ionizing radiation.

• Analytical Science and Technology
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• v.35 no.2
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• pp.69-81
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• 2022

The method of measuring and classifying the energy category of neutrons directly using raw data acquired through a CZT detector is not satisfactory, in terms of accuracy and efficiency, because of its poor energy resolution and low measurement efficiency. Moreover, this method of measuring and analyzing the characteristics of low-energy or low-activity gamma-ray sources might be not accurate and efficient in the case of neutrons because of various factors, such as the noise of the CZT detector itself and the influence of environmental radiation. We have therefore developed an efficient method of analyzing radiation characteristics using a neutron and gamma-ray analysis algorithm for the rapid and clear identification of the type, energy, and radioactivity of gamma-ray sources as well as the detection and classification of the energy category (fast or thermal neutrons) of neutron sources, employing raw data acquired through a CZT detector. The neutron analysis algorithm is based on the fact that in the energy-spectrum channel of 558.6 keV emitted in the nuclear reaction ¹¹³Cd + ¹n → ¹¹⁴Cd + in the CZT detector, there is a notable difference in detection information between a CZT detector without a PE modulator and a CZT detector with a PE modulator, but there is no significant difference between the two detectors in other energy-spectrum channels. In addition, the gamma-ray analysis algorithm uses the difference in the detection information of the CZT detector between the unique characteristic energy-spectrum channel of a gamma-ray source and other channels. This efficient method of analyzing radiation characteristics is expected to be useful for the rapid radiation detection and accurate information collection on radiation sources, which are required to minimize radiation damage and manage accidents in national disaster situations, such as large-scale radioactivity leak accidents at nuclear power plants or nuclear material handling facilities.