• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.3
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• pp.227-231
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• 2008

A latchup-free design based on the lateral diffused MOS (LDMOS) adopting the "Darlington" approaches was designed. The use of Darlington configuration as the trigger circuit results in the reduction of the size of the circuit when compared to the conventional inverter driven RC-triggered MOSFET ESD power clamp circuits. The proposed clamp was fabricated using a $0.35{\mu}m$ 60V BCD (Bipolar CMOS DMOS) process and the performance of the proposed clamp was successfully verified by TLP (Transmission Line Pulsing) measurements.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.97-98
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• 2006

High current behaviors of extended drain n-type metal-oxide-semiconductor field effects transistor (EDNMOS) with double polarity source (DPS) for electrostatic discharge (ESD) protection are analyzed. Simulation based contour analyses reveal that combination of bipolar junction transistor operation and deep electron channeling induced by high electron injection gives rise to the second on-state. Therefore, the deep electron channel formation needs to be prevented in order to realize stable and robust ESD protection performance. Based on our analyses, general methodology to avoid the double snapback and to realize stable ESD protection is to be discussed.

• Journal of the Korean Society of Safety
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• v.13 no.3
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• pp.80-87
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• 1998

This paper presents a study on the development of discharge model and computer program for assessing the risk of electrostatic discharge(ESD) of charged human body This ESD event is modelled as a two-body problem using spherical conductors, simulating the approach of a charged conductor (human body) to a second conductor (electronic equipment). The charge/discharge process for the model is formulated as a matrix of equations by Maxwell's method. Body potentials, energies and the charge transfer during a discharge are calculated. The developed program, based on the suggested scheme in this paper, is applied to a sample system. The results provide a better understanding of ESD event and demonstrate the usefulness of two-body model in practical applications.

• Journal of Power Electronics
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• v.12 no.6
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• pp.947-953
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• 2012

The latch-up immunity of the high voltage power clamps used in high voltage ESD protection devices is very becoming important in high-voltage applications. In this paper, a stacking structure with a high holding voltage and a high failure current is proposed and successfully verified in 0.18um CMOS and 0.35um BCD technology to achieve the desired holding voltage and the acceptable failure current. The experimental results show that the holding voltage of the stacking structure can be larger than the operation voltage of high-voltage applications. Changes in the characteristics of the stacking structure under high temperature conditions (300K-500K) are also investigated.

• Journal of IKEEE
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• v.26 no.2
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• pp.196-204
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• 2022

Electrostatic discharge (ESD) protection devices of P-type embedded silicon-controlled rectifier (PESCR) structure were analyzed for high-voltage operating input/output (I/O) applications. Conventional PESCR standard device exhibits typical SCR characteristics with very low-snapback holding voltages, resulting in latch-up problems during normal operation. However, the modified device with the counter pocket source (CPS) surrounding N⁺ source region and partially formed P-well (PPW) structures proposed in this study could improve latch-up immunity by indicating high on-resistance and snapback holding voltage.

• Journal of Digestive Cancer Research
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• v.11 no.1
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• pp.15-20
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• 2023

Endoscopic submucosal dissection (ESD) is a minimally invasive and effective treatment for early gastric cancer. The criteria for determining the suitability and success of ESD have expanded, with changes in the histopathological classification of gastric carcinoma, including results from molecular research. Treatment methods have also diversified to include targeted therapies and immuno-oncology agents. To improve communication between clinicians and pathologists, it is crucial to understand the standardized diagnostic forms of gastric cancer. This study aims to examine the handling method of ESD specimens and describe the pathological findings of gastric tumors.

• Clinical Endoscopy
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• v.55 no.1
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• pp.15-21
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• 2022

Endoscopic submucosal dissection (ESD) is the standard treatment method for esophageal, gastric, and colorectal cancers. However, it has not been standardized for duodenal lesions because of its high complication rates. Recently, minimally invasive and simple methods such as cold snare polypectomy and underwater endoscopic mucosal resection have been utilized more for superficial nonampullary duodenal epithelial tumors (SNADETs). Although the rate of complications associated with duodenal ESD has been gradually decreasing because of technical advancements, performing ESD for all SNADETs is unnecessary. As such, the appropriate treatment plan for SNADETs should be chosen according to the lesion type, patient condition, and endoscopist's skill.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.903-909
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• 2023

The purpose of this study is to compare and analyze the effect of changes in the patient's central position on the exposure dose and image quality of surrounding organs during a chest lateral examination using an Auto Exposure Control(AEC). The experiment was conducted on a human body phantom. A needle was attached to the lower part of the center of the coronal plane of the phantom, and a lead ruler was attached to the lower part of the detector so that the 50 cm point was located at the lower center of the AEC ion chamber. The exposure conditions were 125 kVp, 320 mA, the distance between the source and the image receptor was 180 cm, and the exposure field size was 14 × 17 inches. Only one AEC ion chamber was used at the bottom center, and the density was set to '0' and sensitivity to 'Middle', and the central X-ray was incident vertically toward the 6th thoracic vertebra. With AEC mode applied, the 50 cm point of the needle and lead ruler were aligned and the phantom was moved 5 cm toward the stomach (F5) and 5 cm toward the back (B5), and the dose factor was analyzed by measuring ESD. The ESD of the thyroid gland according to the change in patient center position was 232.60±2.20 μGy for Center, 231.22±1.53 μGy for F5, and 184.37±1.19 μGy for B5, and the ESD of the breast was 288.54±3.03 μGy for Center, F5 was 260.97±1.93 μGy, B5 was 229.80±1.62 μGy, and the ESD of the center of the lung was 337.02±3.25 μGy for Center, F5 was 336.09±2.29 μGy, and B5 was 261.76±1.68 μGy. As a result of comparing the average values of dose factors between each group, the difference in average values was statistically significant (p<0.01), and each group appeared to be independent. As a result of the study, there was no significant difference in the dose to the thyroid, breast, and center of the lung according to the change in the patient's central position, except for the breast (10%) when the patient moved forward about 5 cm. However, movement of about 5 cm posteriorly resulted in an average dose reduction of 23.7%. Additionally, when the patient's central position was moved to the rear, image quality deteriorated.

• Journal of radiological science and technology
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• v.39 no.3
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• pp.407-414
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• 2016

This study is to minimize the patient dose and maintain the image quality according to change of source to image receptor distance and applying additional filter. In this study, we used the DR system, the tissue-equivalent abdomen phantom and the aluminium filter. The exposure conditions were set to 80 kVp using AEC mode. The collimation size was $16{\times}16inch$. The exposure dose were measured 10 times when the SID was changed with 100, 110, 120 and 130 cm, respectively. The pirana 657 for dosimeter was located on center of radiation irradiation. The acquired images were analyzed by using the image J. In the results, the tube current was increased with increasing the SID but ESD was decreased with increasing the SID. The decrease of ESD attribute to use of filter that remove the photon of lower energy. In the histogram results using image J, there were differences between the ESD and the exposure conditions according to change of SID. However, there were not differences in histogram. Therefore, the exposure dose could reduced when set the longer SID. For pediatric exam, the exposure dose could reduced when used the aluminium filter.

• Journal of radiological science and technology
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• v.44 no.2
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• pp.85-90
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• 2021

The purpose of this study is to consider usefulness of using AEC mode and importance of patient center location in L-spine lateral radiography by comparing dose and image quality according to the change of patient center location with using AEC mode or not. In this study, guide wire is attached to the human body phantom's lumbar spine and the lead ruler is attached to the bottom of the wall detector to find out center location in detector. ESD, mAs, and EI were selected as dose factors, and image quality was compared through SNR. With the lumbar spine located center of the detector, dose factors and image quality were compared according to using AEC mode or not. Afterwards, phantom moved 4 cm and 8 cm back and forth and compared dose factors and image quality. The exposure parameters were 85 kVp, 320 mA, x-ray field size 10×17 inch, and the distance between the center X-ray and the detector was fixed at 100 cm. The center X-ray was perpendicular to the fourth lumbar spine and the only bottom AEC chamber was used. All data were analyzed by independent t-test and ANOVA. As a result of this study, with AEC when the center is matched, ESD was 1.31±0.01 mGy, without AEC was 2.12±0.01 mGy. SNR was shown to be 22.81±1.83, and 23.44±1.87 respectively. When the phantom's center moves 4 cm, 8 cm forward, and 4 cm, 8 cm backward, ESD were 1.09±0.004 mGy, 0.32±0.003 mGy, 1.19±0.017 mGy, 1.11±0.006 mGy respectively, SNR were 18.29±0.60 dB, 11.11±0.22 dB, 18.98±0.80 dB, 17.71±0.82 dB. Using AEC in L-spine lateral radiography reduced ESD by 38%, EI by 35%, and mAs by 38%, without any difference in SNR(p<0.05). When the phantom's center moves 4 cm, 8 cm forward, and 4 cm, 8 cm backward, ESD was decreasing each 16%, 75%, 9%, 15%, EI was decreasing each 14%, 77%, 15%, 20%, mAs was decreasing each 15% 75% 9%, 15%. SNR was decreasing each 19%, 51%, 17%, 22%.