• Journal of radiological science and technology
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• v.3 no.1
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• pp.49-55
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• 1980

To know the effect of tube voltage to X-ray film image, authors made an experimental study on the exponential value of applied voltage and the effect of scattered ray in photographic contrast, and obtained the results as follows: 1. The exponential value of tube voltage was under the control of the applied voltage, the kinds of screens and grids, and its existence. The range of its value was from 1.03 to 5.3. 2. The efficiency of X-ray production was directly proportional to the applied voltage, and to oftain the same density, the tube current(mAs) was inversely proportional to applied voltage 3. The production of scattered rays was in proportion to the tube voltage, and the photographic contrast was mainly influenced by the scattered rays.

• Journal of radiological science and technology
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• v.16 no.2
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• pp.45-50
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• 1993

In this paper, the PAE of tube voltage of 93 diagnostic X-ray units those are using at the 19 general hospitals and 9 local clinics in the area of Sungnam, Inchun, and Seoul have been surveyed. The results are summarized as following. 1. PAE of tube Voltage 70, 100KV at the 56 (60%) X-ray units were ${\pm}7%$ below, at the 8 units (9%), were ${\pm}7%$ above, and those 29 X-ray units (31%) were ${\pm}7%$ below or above with the 70, 100KV tube Voltage in a unit. 2. PAE ${\pm}7%$ below were 68 X-ray units, at the low tube voltage (70KV), and 76 X-ray units at the high tube Voltage (100KV). 3. For six year-use abofe, used X-ray units were PAE ${\pm}7%$ above, and so, the longer used years the more X-ray units became declined in those performance. 4. PAE of tube Voltage were better efficiency at the large capacity 30 X-ray units than small capacity 10. 5. PAE ${\pm}7%$ abovein were only 8 units among 84 diagnostic X-ray units in the general hospitals.

• Journal of radiological science and technology
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• v.44 no.4
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• pp.295-300
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• 2021

This study aims to present new chest AP examination exposure conditions through a study on the effect on image quality and patient dose by applying high tube voltage and scatter ray post-processing software during chest AP examination in digital radiography equipment. This study was used a human body phantom and in the chest AP position, the dosimeter was placed horizontally at the thoracic spine 6. The experiment was conducted by dividing into a low tube voltage (70 kVp, 400 mA, 3.2 mAs) group and a high tube voltage (100 kVp, 400 mA, 1.2 mAs) group. The collimation size (14″× 17″) and the source to image receptor distance(110 cm) were same applied to both groups. Radiation dose was presented to dose area product and entrance surface dose. Image quality was compared and analyzed by comparing the difference between the signal-to-noise ratio and the contrast-to-noise ratio of the image according to the application of the scatter ray post-processing software under each condition. The average value of the entrance surface dose in the low and high tube voltage conditions was 93.04±0.45 µGy and 94.25±1.51 µGy, which was slightly higher in the high tube voltage condition, but the dose area product was 0.97±0.04 µGy and 0.93±0.01 µGy. There was a statistically significant difference in the group mean value(p<0.01). In terms of image quality, the values of the signal-to-noise ratio and the contrast noise ratio were higher in the high tube voltage than in the low tube voltage, and decreased when the scattering line post-processing function was used, but the contrast resolution was improved. If there is a scatter ray post-processing function during chest AP examination, it is helpful to actively utilize it to improve the image quality. However, when this function is not available, I thought that applying a higher tube voltage state than a low tube voltage state will help to realize images with a large amount of information without changing the dose.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.1
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• pp.36-41
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• 2011

Medical X-ray has been brought many changes according to the rapid development of high technology. Especially, for high-voltage generator which is the most important in X-ray generation the traditional way is to use high-voltage electric transformers primarily. However, since it is large and heavy and the ripple rate of DC high-voltage applied to X-ray tube is too big, it has a disadvantage of low X-ray production efficiency. To solve these problems, the studies about high-voltage power supply are now proceeding. At present, the high-voltage generator that generates high-voltage by making high frequency using inverter control circuit consisting of semiconductor device is mainly used. High-voltage generator using inverter has advantages in the diagnosis using X-ray including high performance with short-term use, miniaturization of power supply and ripple reduction. In this study, the X-ray high-voltage device with inverter type using pulse width modulation scheme to the control of tube voltage and tube current was designed and produced. For performance evaluation of produced device, the control signal analysis, irradiation dose change and beam quality depending on the load variation of tube voltage and tube current were evaluated.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.E1
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• pp.29-38
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• 2007

A cylindrical tube connection that has a voltage difference and is separated electrically by an insulator was modelled. The penetration efficiencies of charged particles passing through the connector tube were investigated. Typically, as the particle size decreases and the applied voltage difference increases, the penetration efficiency decreases. To assess the effect of the electrode geometry, various lengths of electric insulator and aerosol flow rate with a fixed tube length and tube diameter were used when calculating penetration efficiencies. The comparison of penetration efficiencies for various electrode geometry setups suggests that the penetration efficiency can be described as a function of the product of applied voltage and electrical mobility of charged particles. The diffusion loss from this and previous studies are compared. Further, an explicit form for penetration efficiency is provided as a function of a new non-dimensional parameter, $Es(=Z_pV/U_{avg}W);\;P_{es}=0.2{\cdot}{\exp}(-Es/0.6342)+0.8{\cdot}{\exp}(-Es/4.7914)$.

• Imaging Science in Dentistry
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• v.42 no.1
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• pp.1-4
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• 2012

Purpose : Hand-held dental x-ray system is a self contained x-ray machine designed to perform intraoral radiography with one or two hands. The issue about its usage as general dental radiography is still in dispute. The aim of the present study was to assess the relationship between the amount of battery charge and the tube voltage in different handheld dental x-ray systems. Materials and Methods : Seven hand-held dental x-ray units were used for the study. Tube voltage was measured with Unfors ThinX RAD (Unfors Instruments AB, Billdal, Sweden) for 3 consecutive exposures at the different amount of battery charge of each unit. The average and the deviation percentage of measured kV from indicated kV of each unit were calculated. Results : Tube voltage of only 1 unit was 70 kV (indicated by manufacturer) and those of the others were 60 kV. Tube voltage deviation percentage from the indicated kV at the fully charged battery was from 2.5% to -5.5% and from -0.8% to -10.0% at the lowest charged battery. Conclusion : Tube voltages of all units decreased as the residual amount of the battery charge decreased. It is suggested that the performance test for hand-held x-ray system should be performed for the minimum residual charged battery as well as the full charged one. Persistent battery charging is suggested to maintain the proper tube voltage of the hand-held portable x-ray system.

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.278-281
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• 1999

The purpose of this study is to investigate the effect of the scattered x-rays on the subject contrast and image sharpness for various tube voltages. For the purpose, we measured the scatter-to-primary ratio(SPR) for the tube voltages f 50 to 100kV and obtained the tube voltage dependence of the subject contrast of an aluminum plate in a polymethyl methacrylate(PMMA) phantom. Furthermore, the overall modulation transfer functions(MTFs), which consist of MTFs of a screen-film system and scatter FTMs, were obtained for tube voltages of 50 to 100 kV. The subject contrast decreased with the tube voltage due to that the SPR increased with the tube voltage and that the difference in effective linear attenuation coefficients between the object and its surroundings decreased with the tube voltage. The maximum frequency of the overall MTF decreased from about 2 mm$\^$-1/ to 1 mm$\^$-1/ with the tube voltage increasing from 50 to 100 kV.

• Journal of the Korean Society of Radiology
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• v.11 no.2
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• pp.79-85
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• 2017

The purpose of this study is to investigate the cause analysis according to the difference between the pre exposure tube voltage and actual exposure tube voltage in mammography in connection with breast pressure thickness, breast size and body mass index and to find the improvement. The study tracked 377 women age 40 and older among the mammography examiners conducted by the National Health Insurance Corporation. It was analyzed that breast pressure thickness, breast size and body mass index according to the difference between the pre exposure tube voltage and actual exposure tube voltage among the parameters of dose report been sent to the picture archiving communication system with reference to the image with cranio-caudal projection in mammography. As are result, it shows that the thicker the breast thickness, smaller the breast size and lower body mass index, the higher the difference of tube voltage. In conclusion, the minimum tube voltage of mammography machine should be reset in order to set the tube voltage according to breast pressure thickness and breast size that are suitable for our country in mammography, in addition, it was considered that radiologist should make an effort to reduce radiation exposure and make a good quality image with reducing the difference of mammography condition by making a correct exposure condition in case of examining the patients with thin breast pressure and small breast size.

• Proceedings of the KIEE Conference
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• 2003.07e
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• pp.162-165
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• 2003

A resonant type voltage source and power device and a control method using Pulse Density Modulation(PDM) power control and Pulse Width Modulation(PWM)voltage control for plasma sterilization are described. For the stability of discharge in the generating tube, it is desirable that the peak apply voltage is constant. The PDM power control is employed for sustaining the voltage constant at any generating tube input power. Moreover, to avoid the influence of input AC voltage fluctuation etc., PWM voltage control with generating tube peak voltage feedback is used. Both functions were confirmed by the experiment with inverter and generating tube. The effect of input synchronous PDM method for input current stabilizing is confirmed also.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.139-142
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• 2002

A resonant type voltage source and power device and a control method using Pulse Density Modulation(PDM) power control and Pulse Width Modulation(PWM) voltage control for Ozone Generator are described. For the stability of discharge in the generating tube, it is desirable that the peak apply voltage is constant. The PDM power control is employed for sustaining the voltage constant at any generating tube input power. Moreover, to avoid the influence of input AC voltage fluctuation etc., PWM voltage control with generating tube peak voltage feedback is used. Both functions were confirmed by the experiment with 6.5[kHz], 1.8[kW] inverter and generating tube. The effect of input synchronous PDM method for input current stabilizing is confirmed also.