A CMOS Hysteretic DC-DC Buck Converter with a Constant Switching Frequency

Jeong, Taejin,Yoon, Kwang S. The Institute of Electronics and Information Engin 2015 Journal of semiconductor technology and science Vol.15 No.4

This paper describes a CMOS hysteretic DC-DC buck converter with a constant switching frequency for mobile applications. The inherent problems of a large output ripple voltage that the conventional hysteretic DC-DC buck converters has faced have been resolved by using the proposed DC-DC buck converter which employed a ramp generator circuit to be able to increase a switching frequency. The proposed architecture enables the settling response time of charge pump circuit within the converter to become less than 6us suitable for mobile applications. The proposed DC-DC buck converter was implemented by using 0.35 um BCDMOS process and die size was $1.37mm{\times}1.37mm$. The measurement results showed that the proposed circuit received the input of 3.7 V and generated output of 1.2 V with the output ripple voltages less than 20 mV under load currents of 100~400 mA at the fixed switching frequency of 2 MHz. The maximum efficiency of the proposed hysteretic buck converter was measured to be around 93%.

A CMOS Hysteretic DC-DC Buck Converter with a Constant Switching Frequency

Taejin Jeong,Kwang S. Yoon 대한전자공학회 2015 Journal of semiconductor technology and science Vol.15 No.4

This paper describes a CMOS hysteretic DC-DC buck converter with a constant switching frequency for mobile applications. The inherent problems of a large output ripple voltage that the conventional hysteretic DC-DC buck converters has faced have been resolved by using the proposed DCDC buck converter which employed a ramp generator circuit to be able to increase a switching frequency. The proposed architecture enables the settling response time of charge pump circuit within the converter to become less than 6us suitable for mobile applications. The proposed DC-DC buck converter was implemented by using 0.35 um BCDMOS process and die size was 1.37 mm x 1.37 mm. The measurement results showed that the proposed circuit received the input of 3.7 V and generated output of 1.2 V with the output ripple voltages less than 20 mV under load currents of 100~400 mA at the fixed switching frequency of 2 MHz. The maximum efficiency of the proposed hysteretic buck converter was measured to be around 93%.

Overexpression of Neuron-Specific Enolase as a Prognostic Factor in Patients with Gastric Cancer

Park, Taejin,Lee, Young-Joon,Jeong, Sang-Ho,Choi, Sang-Kyung,Jung, Eun-Jung,Ju, Young-tae,Jeong, Chi-Young,Park, Miyeong,Hah, Young-Sool,Yoo, Jiyun,Ha, Woo-Song,Hong, Soon-Chan,Ko, Gyung Hyuck The Korean Gastric Cancer Association 2017 Journal of gastric cancer Vol.17 No.3

Purpose: Enolase is a cytoplasmic enzyme that catalyzes the conversion of 2-phosphoglycerate to phosphoenolpyruvate in the glycolytic pathway. The aim of this study was to investigate whether the overexpression of neuron-specific enolase (NSE) can serve as a prognostic factor in patients with gastric cancer (GC). Materials and Methods: To assess its prognostic value in GC, NSE expression was measured by immunohistochemistry in a clinically annotated tissue microarray comprising of 327 human GC specimens. Cytoplasmic NSE expression was scored from 0 to 4, reflecting the percentage of NSE-positive cells. Results: In terms of histology as per the World Health Organization criteria (P=0.34), there were no differences between the NSE overexpression (NSE-OE) and NSE underexpression (NSE-UE) groups. The NSE-OE group showed a significantly lower rate of advanced GC (P<0.01), lymph node metastasis (P=0.01), advanced stage group (P<0.01), cancer-related death (P<0.01), and cancer recurrence (P<0.01). Additionally, a Kaplan-Meier survival analysis revealed that the NSE-OE group had longer cumulative survival times than the NSE-UE group (log-rank test, P<0.01). However, there were no significant differences in the serum levels of NSE expression in patients with GC and healthy volunteers (P=0.28). Conclusions: Patients with NSE overexpressing GC tissues showed better prognostic results, implying that NSE could be a candidate biomarker of GC.

Squamous cell carcinoma occurring in site of A-V fistula ulcer lesion

( Haebong Jeong ),( Yunsun Moon ),( Doseon Jeong ),( Seokrim Kim ),( Chiyeon Kim ),( Taejin Yoon ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

End-stage renal disease patients have an increasedincidence of skin cancers, predominantly on sun-exposed surfaces. Clinical observation identified some patients with an increased number of viral warts, keratosis, and skin malignancies on the side of the arteriovenous fistula. The risk of squamous cell carcinoma(SCC) is significantly increased in chronic cutaneous ulcers. Non-melanoma skin cancer is not only the most common malignancy in transplant patients but is also substantially more aggressive with higher rates of recurrence. We describe the clinical presentation, imaging and pathological findings of squamous cell carcinoma of the arteriovenous fistula ulcer lesion.

Angiolipoma probably caused by vibratory machine

( Haebong Jeong ),( Yunsun Moon ),( Doseon Jeong ),( Seokrim Kim ),( Chiyeon Kim ),( Taejin Yoon ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

Angiolipoma is a morphological variation of the lipoma and is a benign tumour that consists of mature adiposetissue and proliferating blood vessels. The tumor resembles lipomas clinically, but develops in young adults, and favored sites for this tumor are the arms and trunk. The tumor itself is smooth, mobile, and slightly firmer than a subcutaneous lipoma, of rubbery consistency, and the overlying skin is unattached. Angiolipoma frequently occurred at sites of repeated pressure or trauma. We herein, report a case of a young male, presenting with multiple deep seated nodules over the both forearm and neck, Rt. axillary. He usually used vibratory machine in working place. Both arm lesion was histopathological examination revealed, encapsulated benign tumor, comprising of proliferated small-caliber vascular channels with microthrombi and variable amounts of mature adipose tissue. But other site was not. So we report a case that both arm lesion probably associated with vibratory machine with literature review.

Atypical case of demodecidosis

( Haebong Jeong ),( Yunsun Moon ),( Doseon Jeong ),( Seokrim Kim ),( Chiyeon Kim ),( Taejin Yoon ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

The importance of demodicids(Demodex folliculorum and D. brevis) infestation and their effect on skin lesions has been described based on literature data. These organisms reside in the hair follicle and the infundibulum of the sebaceous gland, respectively. Hair follicle mites have been detected in 45% of patients with rosacea, 27% of patients with perioral dermatitis, 28% of patients suffering from seborrheic dermatitis and some patients with chronic blepharitis. Clinical picture of demodecosis included erythemato-papulous and pustulous(rosacea-like) skin lesions together with erythemato-desquamative changes of the face. We describe the clinical presentation, imaging and pathological findings of atypical case of demodecidosis.

지방공무원 교육훈련 인식실태와 개선방안 연구

정태진 ( Taejin Jeong ),주상현 ( Sanghyeon Ju ) 한국정책연구원 2023 한국정책논집 Vol.23 No.0

지방자치시대 지방공무원의 역할은 나날이 증대되고 되고 있다. 따라서 지방공무원 역량강화를 위한 교육훈련은 지방자치단체의 지속적인 발전과 시민들에게 양질의 서비스를 제공하기 위해서 매우 중요하다. 이 연구는 지방자치단체의 성장·발전의 토대가 되는 지방공무원들의 교육훈련에 대한 인식조사를 통해 교육훈련 강화를 위한 효율적인 방안을 모색해 보는데 연구 목적을 두고 있다. 이를 위해 거제시청에 근무하는 지방공무원들을 대상으로 2023년 7월 25일부터 8월 8일까지 설문조사를 실시하였다. 설문대상은 248명이며, 분석변수는 교육만족도, 교육운영 내용, 집합 및 온라인교육, 통찰력 및 직관력 교육, 장기교육 등으로 구분하여 조사를 하였고, 빈도분석을 수행하였다. 분석결과 첫째, 교육훈련 만족도는 비교적 높은 것으로 나타났으며, 교육훈련의 필요성도 높게 인식하고 있는 것으로 나타났다. 둘째, 직무 역량강화와 개인 능력개발 등 두 가지를 교육훈련의 가장 중요한 요소로 여기고 있었다. 셋째, 응답자들의 절반 이상이 집합교육 방식을 선호하지만 온라인 위주의 교육훈련이 중심이었다. 넷째, 지방공무원들이 현안 문제의 중심을 통찰하고 대안을 제시할 수 있는 혜안을 기르는 것이 중요하다. 다섯째, 지방공무원들이 자기계발과 함께 지역문제 해결을 위한 안목이 필요하다. 이에따라 이 연구는 다음과 같은 정책적 시사점을 제시하였다. 첫째, 맞춤형 교육훈련 제공이 필요하다. 둘째, 리더십과 문제해결 능력 향상이 요구된다. 셋째, 실질적인 교육훈련 시간 보장이 필요하다. 넷째, 인문학적 소양 및 힐링 교육이 필요하다. 다섯째, 민간 참여를 통한 교육 거버너스 구축이 요구된다. In the era of local autonomy, the role of local public officials is increasing day by day. Therefore, education and training to strengthen the capabilities of local public officials is very important for the continuous development of local governments and to provide quality services to citizens. The purpose of this study is to find efficient ways to strengthen education and training through a survey of local public officials' perceptions of education and training, which is the foundation for the growth and development of local governments. For this purpose, a survey was conducted targeting local public officials working at Geoje City Hall from July 25 to August 8, 2023. The subjects of the survey were 248 people, and the analysis variables were divided into training satisfaction, training operation content, group and online training, insight and intuition training, and long-term training, and frequency analysis was performed. As a result of the analysis, first, satisfaction with education and training was found to be relatively high, and the need for education and training was also highly recognized. Second, job competency strengthening and personal competency development were considered the most important elements of education and training. Third, more than half of the respondents preferred group education, but online education and training were the main focus. Fourth, it is important for local public officials to develop insight into the core of pending problems and to suggest alternatives. Fifth, local public officials need self-development and insight into solving local problems. Accordingly, this study presented the following policy implications. First, it is necessary to provide customized education and training. Second, improvement in leadership and problem-solving skills is required. Third, it is necessary to guarantee practical education and training time. Fourth, humanities knowledge and healing education are needed. Fifth, the establishment of educational governance through private sector participation is required.

Angiosarcoma following irradiation therapy

( Haebong Jeong ),( Yunsun Moon ),( Doseon Jeong ),( Seokrim Kim ),( Chiyeon Kim ),( Taejin Yoon ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

Cutaneous angiosarcoma is a rare, aggressive malignant tumor of vascular endothelial cells difficult to differentiate from carcinoma or melanoma, with poor prognosis. It may occur in different organs, but 50% of the patients the cancer localized to the skin of the head and neck region and varies in clinical manifestations including purpuric macules, and/or papules and nodules of bright red or violaceous and even black color, and progresses rapidly for several months. Potentially arising in many anatomic sites and organs, they may be sporadic or the result of exposure to environmental conditions such as radiation, long-term lymphedema (Stewart-Treves syndrome), trauma, chronic infection or chemical agents(e.g.,vinylchloride, arsenic medication, steroids). Despite this variability, Angiosarcoma shares an invasiveness behavior consisting of local recurrence and an early hematogenous and lymphogenous dissemination. We describe the clinical presentation, imaging and pathological findings of secondary angiosarcoma of the abdomen after radiotherapy.

적외선 거리 센서를 이용한 시소형 볼 밸런서

정규만(Gyu-Man Jeong),김훈정(Hoon-Jeong Kim),오승택(Seung-Taek Oh),박태진(Taejin Park) 대한전기학회 2018 대한전기학회 학술대회 논문집 Vol.2018 No.-

Tumor-Suppressing Effect of Silencing of Annexin A3 Expression in Breast Cancer

Kim, Ju-Yeon,Jung, Eun Jung,Park, Hee Jin,Lee, Jeong-Hee,Song, Eun Jin,Kwag, Seung-Jin,Park, Ji-Ho,Park, Taejin,Jeong, Sang-Ho,Jeong, Chi-Young,Ju, Young-Tae,Lee, Young-Joon,Hong, Soon-Chan Elsevier 2018 Clinical breast cancer Vol.18 No.4

<P><B>Abstract</B></P> <P><B>Introduction</B></P> <P>Annexin A3 (ANXA3) participates in various tumor-associated biological processes, including tumor initiation, progression, and metastasis. The present study was designed to investigate the expression and function of ANXA3 in breast cancer cells.</P> <P><B>Materials and Methods</B></P> <P>Annexin A3 protein expression in breast cancer cell lines was evaluated using Western blot analysis. ANXA3 expression in MDA-MB 231 breast cancer cells was silenced by RNA interference, and the effects of RNA silencing on cell proliferation, colony forming ability, wound-healing, and invasiveness were evaluated. Levels of ANXA3 expression in 30 primary breast cancers were assayed using immunohistochemistry and correlated with patient survival.</P> <P><B>Results</B></P> <P>Levels of ANXA3 expression were higher in the basal subtype of breast cancer cells, such as MDA-MB 231, HCC-70, and HCC-1954 cells, than in other subtypes. ANXA3 silencing inhibited the activities of MDA-MB 231 and HCC-1954 cells, including their proliferation, invasion across transwell membranes, and wound-healing and colony forming abilities. ANXA3 small interfering RNA (siRNA) also reduced the expression of cycle-dependent kinase protein and increased the expression of E2F1 and p27 proteins compared with control siRNA. Expression of ANXA3 was closely correlated with tumor size, with higher ANXA3 expression associated with reduced disease-free survival in breast cancer patients.</P> <P><B>Conclusion</B></P> <P>These findings indicate that ANXA3 is associated with the natural progression of breast cancer and might be a potential prognostic marker of patient survival.</P>