• Journal of the Korean Society of Radiology
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• v.11 no.6
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• pp.459-466
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• 2017

The purpose of this study was to evaluate the difference of dose and image quality according to the material of the additional filter plate by selecting copper and nickel. First, the absorbed dose was measured using a Rando phantom setting the additional filter plates of copper and nickel None, 0.1 mm, 0.2 mm, and 0.3 mm under 120 kVp, and 6.3 mAs. Second, We acquired image according to filter thickness of copper and nickel. by changing the tube voltage of 90 kVp, 100 kVp, 110 kVp, 120 kVp and exposure indexes of 400, 800 and 1600. Third, we obtained the SNR and CNR values using the Image J program and evaluated quantitatively and then evaluated image quality. As a result, Absorbed dose measurements showed that nickel was higher than copper, and the absorbed dose decreased as the thickness increased(p<0.05). Furthermore, Quantitative analysis of images showed no significant difference between the two images according to change the voltage and the exposure index(p>0.05). In conclusion, this study confirms that the nickel addition plate can maintain the current image quality while reducing the exposure dose compared to copper.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.685-691
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• 2023

This study aims to raise awareness of the exposure index according to the Sub-ROI in clinical use by studying the effect of Sub-ROI's change on exposure index and dose during Chest PA examination. In this study, to examine the changes in EI and ESD according to the Sub-ROI setting, the irradiation conditions were set to 120 kVp, 200 mA, 2 mAs, and the SID was fixed to 180cm. Five types of Sub-ROI were used. The average value of EI according to the Sub-ROI's change was 135.58 ± 0.89 in AEC, 100.80 ± 0.80 in VR, 143.43 ± 0.76 in HR, 103.22 ± 0.68 in LS, and 102.79 ± 0.84 in SS. The mean value of ESD was 30.28±0.50 µGy in AEC, 30.16 ± 0.44 µGy in VR, 30.30 ± 0.46 µGy in HR, 30.23 ± 0.46 µGy in LS, and 30.28 ± 0.51 µGy in SS. As a result of this study, based on the AEC mode recommended by the manufacturer, the VR (25.7%), LS (23.9%), and SS (24.2%) modes decreased, and the HR mode increased by 5.7%. However, ESD was not affected by the Sub-ROI's change. Therefore, Sub-ROI may change EI during the Chest PA examination, it is considered that Sub-ROI should be used appropriately when setting protocols in clinical use.

• Journal of radiological science and technology
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• v.14 no.1
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• pp.23-28
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• 1991

Automatic exposure control systems are now readily available and widly used in radiography. A device that automatically determines the amount of radiation required to produce an acceptable level of film blackness is called a phototimer, or automatic exposure control. There are limitations in the use of phototimers ; however, equipment can be used much more effectively if one recognize these limitations, and the goal of obtaining a properly exposed, reproducible radiography can be achieved. We have some results in this experimental study. The variations of film density due to kVp are in propotion to below 80 kVp range. But indicate constant level above 80 kVp to 120 kVp. The characteristic density variation by phantom thickness shows the higher the thiner in exit type. AEC system have a density control that is designed to make adjustments increase or decreas the density 10% per step or 25% per step. The automatic exposure control circuits must meet the several regulations of the HEW. Some forms of technique chart is recomened for use of AEC.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.421-426
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• 2011

This research was accomplished to assess dose effects on image quality at computed radiography (CR). The ultimate target of the research was finding optimized exposure that provides necessary image quality for the clinical chest diagnosis. Modulation transfer function (MTF), normalized noise power spectrum (NNPS), and Noise equivalent quanta (NEQ) corresponding to the different doses were measured for the assessment of image quality. The preparation of "edge test device" used in MTF measurement and experimental geometry setup were followed by the recommendations of International Electrotechnical Commission (IEC). The experimental results show the necessary image quality can be achieved even at a half of the automatic exposure control (AEC) setting dose for chest diagnosis. It means that the patient exposure can be reduced dramatically by using optimized dose.

• Journal of radiological science and technology
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• v.42 no.1
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• pp.25-30
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• 2019

Whole Spine Scanography (WSS) using the Digital Radiography (DR) system is an examination that requires whole body X-ray exposure, which involves more exposure to radiation for patients than other general radiographies. This can affect the occurrence of breast cancer. This research measured radiation dose when breasts were shield and not shield using the Auto Exposure Control (AEC) mode. The radiation dose without a shield was 1.540 mGy, and that using a collimator was measured 0.506 mGy. Moreover, 0.733 mGy was measured when 1 shield (0.3 mm) was used, and $0.523{\mu}Gy$ when 5 of them (1.5 mm) were used. The results showed that the radiation dose with 5 shields and the radiation dose with a collimator were similar. Moreover, 0.233 mGy was measured when 8 shields (2.4 mm) were used. The standard deviation were 0.081 when using collimator and 0.014 when 5 shields were used. Also, when 8 shields were used, it was found to be 0.002. Most patients who go under a scoliosis test are children or young people who are highly sensitive to radiation. In the research results, the case where the organs sensitive to radiation, women's breasts, were shielded showed more distinct differences compared to without shields. It is considered that using shields can provide more constant shield than using a collimator and lower the risk of breast cancer caused by exposure to radiation.

• Journal of radiological science and technology
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• v.44 no.1
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• pp.39-46
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• 2021

This study confirmed the usefulness of the copper filter according to the mode change by comparing and analyzing the energy change according to the application of the copper filter and the change in effective dose and image quality according to the distance to the subject in the DR(Digital Radiography) system. The average energy increased when the copper filter was applied and the reduction rate by 50% of mAs was increased as the thickness of the copper filter increased according to the application of the 10 kVp rule in AEC mode. The effective dose decreased as the thickness increased when the copper filter was applied in AEC(Automatic Exposure Control) mode and manual mode according to the application of the 10 kVp rule, and the decrease rate decreased with increasing 10 kVp increments. As a result of analyzing the dicom images for AEC mode and manual mode with Image J. the PSNR(Peak Signal to Noise Ratio) values were approximate values of less than 30 dB for each mode and for each copper filter thickness. When the copper filter was applied, the average energy increased, so when the 10 kVp rule was applied, the mAs for each mode could be reduced, and the effective dose could also be reduced. However, as the distance and tube voltage increased, the reduction rate of mAs decreased, and the quality of the image was found to decrease when the copper filter was applied, but there was no difference in quality of the image when the copper filter thickness increased.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.5
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• pp.490-499
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• 2002

Recently, gamma radiographic equipments have been used about 1,000 sets manually and operated by about 2,500 persons in Korea. In order for a radiography to work effectively with avoiding any hazard of the high level radiation from the source, many field workers have expected developing a wireless automatic remote exposure controller. The KlTCO research team has developed an automatic remote exposure controller that can regulate the speed of $0.4{\sim}1.2m/s$ by BLDC motor of 24V 200W which has output of $54kgf{\cdot}cm$, suitable torque and safety factor for the work. And the developed automatic remote exposure controller can control rpm of motor, pigtail position by photo-sensor and exposure time by timer to RF sensor. Thus, the developed equipment is expected that the unit can be used in many practical applications with benefits in economical advantage to combine the use of both automatic and manual type because attachment is possible existent manual remote exposure controller, AC and DC combined use.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.640-645
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• 2020

To produce an input device stably using the transparent electromagnetic pattern of an electromagnetic induction method, pattern inspection is required in advance in the production process. Various methods of inspecting the capacitive pattern for hand-touch have been proposed, but it is difficult to find the related technical data for the pattern inspection method of the transparent electromagnetic induction method. In this study, to develop an inspection system for a fused electromagnetic resonance pen sensor with a copper-etched metal mesh pattern, an inspection algorithm and method for measuring the antenna impedance inside the sensor was proposed by measuring only the exposed FPCB connector. The proposed method was configured as a control board consisting of a microprocessor that forms a loop between specific channels according to the command of a computer, a computer-controlled by the Windows program, an LCR meter measuring the impedance between specific channels, and transmitting the measurement results back to the computer. An evaluation of the proposed system and measurements of nine specimens showed that it could detect the defects of the sensor used in the actual product.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.6
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• pp.43-49
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• 2004

Electric pulp test is a method to examine the vitality of dental pulp using physical and chemical stimulation. During the pulp test, the current stimulates intradental nerve, and it makes patients painful. In this paper, we measured each activating response EMG in anterior belly of digastric muscle, voice, and finger movement during the pulp test by increasing stimulus intensity gradually. We also measured excessive stimulus time from the activating responses (EMG, voice, and finger movement) to the end of the stimulation. We measured and analyzed excessive stimulus time for each stimulus detecting method. As a result, we developed automatic stimulus breaker using the human responses to stimulus during electric pulp test. We reduced the excessive stimulus time by disconnecting the pulp tester stimulus output rapidly in 10 ms after activating human response.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.2
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• pp.83-90
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• 2023

Blurred image is an important factor in lowering image recognition rates in Computer vision. This mainly occurs when the camera is unstablely out of focus or the object in the scene moves quickly during the exposure time. Blurred images greatly degrade visual quality, weakening visibility, and this phenomenon occurs frequently despite the continuous development digital camera technology. In this paper, it replace the modified building module based on the Deep multi-patch neural network designed with convolution neural networks to capture details of input images and Attention techniques to focus on objects in blurred images in many ways and strengthen the image. It measures and assigns each weight at different scales to differentiate the blurring of change and restores from rough to fine levels of the image to adjust both global and local region sequentially. Through this method, it show excellent results that recover degraded image quality, extract efficient object detection and features, and complement color constancy.