• Journal of the Korean Society of Radiology
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• v.9 no.2
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• pp.67-72
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• 2015

In diagnostic radiology, the use of automatic exposure control device is internationally recommended for diagnosis and optimization. However, if exposed to prolonged radiation is a complicated manufacturing process, there is a problem that occurs decrease of various performance overall brightness sensor, which is commercially available conventional. Therefore, in this study, absorption of X-ray is high, and I want to evaluate the AEC applicability of the sensor of the photoconductor-based production has an easy advantage. Experimental results confirms the possibility of fabrication of the sensor through an increase in the SNR, with the detection efficiency superior, accurate turn-off. In addition, it is confirmed that the experimental results of the transmittance and the latent image, Ghost effect by the light conductor does not appear, in the case of a photoconductor with the exception of the PbO, 80% - and it was confirmed good transmittance of 90%. Therefore, excellent mechanical stability and poor performance due to a change of the doping concentration than the existing products that have been put to practical use, the sensor easy photoconductor based, fabrication and can be applied as AEC sensor is expected.

• Journal of the Korean Society of Radiology
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• v.18 no.3
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• pp.257-265
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• 2024

In this study, we applied AEC(Auto Exposure Control), which is used in many chest examinations, to evaluate whether medical devices inserted into the body affect the dose and image quality of chest images. After attaching three HIMD(Human implantable medical devices) to the ion chamber, the Monte Carlo methodology-based program PCXMC(PC Program for X-ray Monte Carlo) 2.0 was applied to measure the effective dose by inputting the DAP(Dose Ares Product) value derived from the Pacemaker and CRT and Chemoport Additionally, to evaluate image quality, we set three regions of interest and one noise region on the chest and measured SNR and CNR. The final study results showed significant differences in DAP and Effective dose. There was a significant difference between Pacemaker and CRT when AEC was applied and not applied. (p<0.05) When applied, the dose increased by 37% for Pacemaekr and 52% for CRT. Chemoport showed a 10% increase in effective dose depending on whether AEC was applied, but there was no significant difference. (p>0.05) In the image quality evaluation, there was no significant difference in image quality between all HIMD insertions and AEC applied or not. (p>0.05) Therefore, when the HIMD was inserted into the chest during a chest x ray and overlapped with the ion chamber sensor, the effective dose increased, and there was no difference in image quality even at a low dose without AEC. Therefore, when performing a chest X-ray examination of a patient with a HIMD inserted, it is considered that performing the examination without applying AEC is a method that can be considered to reduce the patient's radiation exposure.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.7
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• pp.61-70
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• 2017

In this paper, an Ethernet equalizer that compensates for automotive temperature variations within a broad range is presented. Communications in automotive systems have become increasingly important because of the many electronics in vehicles. Ethernet protocols are a good candidate for automotive communications. However, they should satisfy the AEC-Q100 requirements that stipulate an operational temperature range from -40 to $150^{\circ}C$. This paper proposes an Ethernet equalizer that can recover data up until 100 m length of CAT-5 cable adaptively within a temperature range of -40 to $150^{\circ}C$. To support the wide temperature range, a feedback system is used. The proposed equalizer has a bandwidth of 31.25 MHz with a fully-differential structure and is implemented in a Hynix $0.13{\mu}m$ BCDMOS technology.

• Journal of the Korean Society of Radiology
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• v.10 no.5
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• pp.321-325
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• 2016

Dose creep is one of clinical errors that arises from the tester's inexperience or carelessness, and according to Task Group #116 of American Association of Physicists in Medicine, its continued occurrence is being reported in the digital method. At this point, the demand for an automatic exposure control device that minimizes the dose creep phenomenon and can improve reproducibility is increasing. In this study is to consider the automatic exposure control device sensor that can is not only easy to produce, but also reduce the dose creep phenomenon by conducting a research on high-efficient semiconductor sensor. As a result, the Intrinsic-type and PIN-type sensors have excellent optical property compared to Ref sensor, would have less shading effect, and have relatively low sensitivity, but would provide accurate feedback signals to automatic exposure control device with its consistent tendency according to exposure condition changes.

• Journal of KIBIM
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• v.2 no.1
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• pp.7-17
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• 2012

In recent years, building information modeling (BIM) has been an important issue within the architect, engineering, and construction (AEC) industry. BIM provides a way to share and exchange semantically rich information about the buildings in order to achieve a successful level of collaboration, communication, and interaction between stakeholders throughout the life cycle of the project. However, despite the recognition of its potential, BIM has not yet been utilized in the construction, operation, and maintenance stages because of the need to reorganize the BIM by reflecting the as-built status of the buildings. In order to improve and increase the use of BIM at all phases of a project, several research efforts are exploring the creation of an as-built BIM that is based on advanced sensors. However, there is a lack of literature and investigation on this research area to date within the domestic AEC industry. The aim of this study is to suggest ways in which BIM can be utilized within the construction, operation, and maintenance stages based on advanced sensors so that it is an approach that might be usefully carried forward. This paper begins by presenting a review of the existing BIM research and achievement in order to determine the limitations of the use of BIM in the domestic AEC industry. Conclusively, this paper suggests a direction for the future applications of BIM and describes how it can benefit from additional research.

• Journal of the Korean Society of Radiology
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• v.9 no.3
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• pp.175-181
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• 2015

In this paper, we studied additional filter and Ion chamber combinations to reduce patient dose without decreasing image quality in digital chest x-ray projection. The experiment set 125 kVp, 320 mA, AEC mode. Ion chamber sensors was divided by 4 cases of combinations, then, we measured patient dose and calculated organ dose using PCXMC. Also, physical image assessment using MTF was performed. As a results, The surface entrance dose and organ dose were the lowest when selecting both left and right Ion chamber sensors under the same conditions of additional filter. In image quality assessment, The spatial frequency scored 2.494 lp/mm which was highest when selecting both right and left Ion-chambers and 0.1 mmCu filter. And to conclude, to select both right and left Ion chamber sensors and 0.1 mmCu filter will help for acquiring good quality image as well as reducing patient dose.

• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.275-283
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• 2013

The patient radiation dose is different depending on selection of Ion chamber when taking Chest PA which using AEC. In this paper, we studied acquiring the best diagnostic images according to selection of Ion chamber on AEC mode as well as minimizing patient radiation dose. Experimental methods were selection of Ion chamber and change of sensitivity under the same conditions as Chest PA projection. At AEC mode, two upper ion chambers sensors and one lower ion chamber sensor were divided into 7 cases according to selection of on/off. after measuring five times respectively, we obtained average value and calculated exposure dose. Image assessment was done with measured Modulation Transfer Function, Peak Signal to Noise Ratio, Root Mean Square, Signal to Noise Ratio, Contrast to Noise Ratio, Mean to Standard deviation Ratio respectively. In exposure assessment results, selection of two upper chambers was the lowest. In resolution assessment results, image of two upper chambers had the second high spatial frequency at sensitivity at 625(High) was 1.343 lp/mm. RMS value of image selecting two upper chambers was low secondly. SNR, CNR, MSR were the high value secondly. As the sensitivity was increased, radiation dose was decreased but better image could be obtained on image quality. In order to obtain the best medical images while minimizing the dose, usage of two upper ion chambers is considered to be clinically useful at sensitivity 625(High).

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.43-48
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• 2007

It is important to measure the rotational accuracy of lathe spindle as it affects to the qualities of all machines machined by the lathe using in industries. The bad rotational accuracy of lathe spindle are caused mainly by wearness of the spindle in using and quality of spindle when machining and using low level bearings. It occurs especially in case of lathes because the cutting force acting to work-piece act on one side to the spindle not to both sides symmetrically. Therefore in this study, constructing experimental apparatus for measuring of rotational accuracy by using eddy current type gap sensors AEC5706PS and sensors, s-06LN, data acquisition board DT9834(USB type) and software for data acquisition, DT Measure Foundry ver. 4.0.7 etc., error data acquired in the rotational accuracy test of lathe spindle are analysed in plots and statistical treatments.

• JSTS:Journal of Semiconductor Technology and Science
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• v.11 no.1
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• pp.1-5
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• 2011

To enter next process control, numerous approaches, including run-to-run (R2R) process control and fault detection and classification (FDC) have been suggested in semiconductor manufacturing industry as a facilitation of advanced process control. This paper introduces a novel type of optical plasma process monitoring system, called plasma eyes chromatic system (PECSTM) and presents its potential for the purpose of fault detection. Qualitatively comparison of optically acquired signal levels vs. process parameter modifications are successfully demonstrated, and we expect that PECSTM signal can be a useful indication of onset of process change in real-time for advanced process control (APC).