Development of Diamond-like Carbon Film as Passivation Layers for Power Transistors

Chang, Hoon,Lee, Hae-Wang,Chung, Suk-Koo,Shin, Jong-Han,Lim, Dae-Soon,Park, Jung-Ho The Korean Ceramic Society 1997 The Korean journal of ceramics Vol.3 No.2

Because of the novel characteristics such as chemical stability, hardness, electrical resistivity and thermal conductivity, diamond-like carbon (DLC) film is a suitable material for the passivation layers. For this purpose, using the PECVD, DLC films were synthesized at room temperature. The adhesion and the hardness of the DLC films deposited on Si an SiO2 substrate were measured. The resistivity of 5.3$\times$$10^8$$\Omega$.cm was measured by automatic spreading resistance probe analysis method. The thermal conductivities of different DLC films were measured and compared with that of phospho silicate glass (PSG) film which is commonly used as passivation layers. The thermal conductivity of DLC film was improved by increasing hydrogen flow rate up to 90 sccm and was better than that of PSG film. The patterning techniques of the DLC film developed using the RIE and the lift-off method to form 5$\mu\textrm{m}$ line. Finally, the thermal characteristics of the power transistor with the DLC film as passiviation layer was analyzed.

청소년의 휴대전화의존이 학교생활적응에 미치는 영향 -진로정체감의 매개효과를 중심으로-

이창훈 ( Lee¸ Chang Hoon ),김현수 ( Kim¸ Hyunsoo ) 한국가족사회복지학회 2021 한국가족복지학 Vol.68 No.3

본 연구의 목적은 청소년이 지각하는 휴대전화의존 정도가 학교생활적응에 어떠한 영향을 미치는지, 그리고 청소년이 지각하는 휴대전화의존 정도와 학교생활적응의 관계에서 진로정체감의 매개효과를 살펴보는 데 있다. 이를 위해 한국 아동·청소년 패널연구의 제6차 패널데이터인 중학교 3학년 학생 2,061명 중, 본 연구의 주제인 휴대전화의존도, 진로정체감, 학교생활적응과 관련된 각 문항에 성실하게 응답한 1,990명의 자료를 대상으로 분석을 실시하였고 그 결과는 다음과 같다. 첫째, 청소년이 지각하는 휴대전화의존도가 학교생활적응에 유의미한 영향을 미치는 것으로 나타났다. 둘째, 청소년이 지각하는 휴대전화의존도가 진로정체감에 유의미한 영향을 미치는 것으로 나타났다. 셋째, 진로정체감은 청소년이 지각하는 휴대전화의존도와 학교생활적응의 관계에서 부분매개효과를 가지는 것으로 확인되었다. 본 연구의 제언에서 연구 결과에 따른 시사점과 제한점을 제시하였다. The purpose of this study is to investigate the effects of mobile phone dependency perceived by adolescents on their adjustment to school life and the mediating effects of career identity on their influential relations. For this purpose, the study examined the data of 2,061 ninth graders in middle school from the sixth panel data of “Korean Children and Youth Panel Survey 2015,” selected the data of 1,990 that provided sincere answers to each of the items related to the topics of the study including mobile phone dependency, career identity, and adjustment to school life, and conducted the three-step mediated regression analysis by Baron and Kenny(1986). The analysis results were as follows: First, mobile phone dependency perceived by adolescents had significant effects on their adjustment to school life; secondly, mobile phone dependency perceived by adolescents had significant effects on their career identity; and finally, career identity had partial mediating effects on influential relations between mobile phone dependency perceived by adolescents and their adjustment to school life. The section of suggestions discussed the implications and limitations of the findings.

Flat-Plate구조에서 장기변형 예측에 관한 연구

성창훈 ( Sung¸ Chang-hoon ),김선영 ( Kim¸ Sun-young ),송진규 ( Song¸ Jin-gyu ) 한국구조물진단유지관리공학회 2002 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.6 No.2

To study on the long-time deflections of Flat-plate slabs considering the removal time of shores, four specimens were manufactured. The days of removal of shores were 6, 12, 18, and 28 day. The current ACI Code and CEB-FIP(1990) Code for one-way slabs were compared with test results. 2 dimensional FEM program using the effective beam width model was applied to analysis of Flat plate slabs. The comparison of the current code with test results was that ACI Code was resemblant in long span but estimated low in short span and CEB-FIP( 1990) Code was estimated a little high at the early ages but was inclined to predict low as time goes on. Furthermore, FEM frame analysis using the effective beam model was reasonable to predict long-term deflections.

Efficacy of Fulvestrant in Heavily Pretreated Postmenopausal Women with Advanced Breast Cancer: A Preliminary Report

Changhoon Yoo,Sung Bae Kim,Jin Hee Ahn,Kyung Hae Jung,Yongchel Ahn,Gyungyub Gong,Hak-Hee Kim,Hee-Jung Kim,손병호,Sei-Hyun Ahn 한국유방암학회 2011 Journal of breast cancer Vol.14 No.2

Purpose: Fulvestrant, a potent estrogen receptor (ER) antagonist with a novel mechanism of action, has shown efficacy in pretreated patients with advanced breast cancer. We assessed the efficacy and tolerability of fulvestrant in Korean postmenopausal women. Methods: Of the 25 candidates identified at Asan Medical Center, Seoul, Korea, six were deemed ineligible due to inadequate baseline and follow-up imaging. The 19 patients included in this retrospective analysis received the approved dose of fulvestrant (250 mg intramuscular injection, once per month) as second- (n=8), third- (n=7), or fourth-line (n=4) endocrine therapy. Results: At a median follow-up of 7.4 months (range, 1.2-34.8 months), the 19 patients received a median of four cycles (range, 1-34 cycles) of fulvestrant. Median time to progression was 5.5 months (95% confidence interval [CI], 0.4-10.7 months), and median overall survival was 17.9 months (95% CI, 2.7-33.1 months). Among 17 evaluable patients, one (5.3%) achieved a partial response, 10 (52.6%) showed stable disease, and six (31.6%) showed progressive disease. The clinical benefit rate was 26.3%. Four patients (21.1%) reported adverse events, but all were grade 1 or 2. Conclusion: Fulvestrant was effective and well tolerated in patients with advanced breast cancer who had been previously treated with several lines of endocrine and chemotherapeutic agents.

The effects of spin-Peierls distortion on thermoelectric properties: a first principle study of TiPO₄

Changhoon Lee,Taesu Park,Ji Hoon Shim 한국자기학회 2021 한국자기학회 학술연구발표회 논문개요집 Vol.31 No.1

We investigated the effects of spin-Peierls distortion on thermoelectric properties by density functional theory calculations. The titanium(III) phosphate, TiPO4, which crystallize in the CrVO4structure type (space group Cmcm), shows low-dimensional magnetic properties and it undergoes a phase transitions towards a dimerized spin-Peierls state driven by the strong spin-exchange interactions. The spin-Peierls distortion increases a bandgap and generates peaks in the density of states at the conduction band minimum (CBM) and valence band maximum (VBM) which evolves strongly enhanced Seebeck coeffcients. Consequently, a spin-Peierls distortion should be considered as an important factor to enhance the power factor (PF) of thermoelectric materials.

Comparison of long-term biliary complications between open and laparoscopic choledochal cyst excision in children

Changhoon Lee,Jeik Byun,Dayoung Ko,Hee-Beom Yang,Joong Kee Youn,Hyun-Young Kim 대한외과학회 2021 Annals of Surgical Treatment and Research(ASRT) Vol.100 No.3

Purpose: Cyst excision with hepaticojejunostomy has been the classic procedure for treating choledochal cysts, and the use of laparoscopic treatment has been favored recently. The purpose of this study was to compare the long-term biliary complication of laparoscopic operation with open surgery for choledochal cyst presenting in children. Methods: A retrospective study comparing the laparoscopic and open procedures was performed in 185 patients with choledochal cyst in a single children’s hospital. There were 109 patients who were operated with open surgery, and 76 patients operated with laparoscopic surgery. The primary outcome was long-term biliary complications and the secondary outcome included operative time, intraoperative transfusion, length of hospital stay, and other late postoperative complications. Results: In the patient’s demographics, there was no significant difference between the 2 groups. Notably, it was shown that the operative time was longer in the laparoscopic group. The number of patients requiring blood transfusion intraoperatively was lower in the laparoscopic group. It was noted that the hospital stay was not statistically different. The duration to resumption of diet and duration of drainage were longer in the laparoscopic group. Biliary complications were shown to be significantly higher in the open group. The risk factor for long-term biliary complications was noted with the intraoperative transfusion. Conclusion: The use of a laparoscopic choledochal cyst excision with hepaticojejunostomy is a safe and feasible technique in a young patient. The long-term biliary complication was lower compared to open surgery, rendering this a good option for pediatric patients.

Practices of Assessing Financial Conditions and Fiscal Health in Local Governments in the United States

Changhoon Jung 한국정부회계학회 2008 정부회계연구 Vol.6 No.1

본 연구는 미국 지방정부들이 어떻게 재정상태와 재정건강을 측정하고 있는 가에 대해서 알아본다. 본 연구에 의하면 미국 지방정부에서 어떻게 재정상태와 재정건강을 측정하는가에 대한 체계적인 연구가 많지 않고 특별히 재정상태를 측정하는데 어떤 지표를 사용하고 있는가에 대해서도 활발한 연구가 없는 실정이다. 이 연구에 의하면 주정부들이 그들의 지방정부에게 정기적으로 재정상태와 재정건강을 측정하고 보고할 의미를 부여하지 않는 한 대부분의 지방정부들은 지방정부차원에서 적극적으로 그들의 재정상태와 재정건강을 측정하지 않는 것으로 나타났다. 본 연구는 GASB Statement 34의통과와 함께 지방정부들에게 2002년부터 부과된 정부차원의 통합재무제표를 바탕으로 지방정부들이 그들의 재정상태와 재정건강을 측정한가를 아울러 살펴보았는데 결과에 의하면 이를 사용하여 정부전체의 자산이나 부채등의 변화상태를 측정하는 지방정부들이 많지 않아 아직까지 지방정부들이 새로운 지표를 이용하여 그들의 재정상태를 보고하기는 이른 것으로 판단한다. This study examines local practices of assessing financial conditions and fiscal health. It shows that not much is known about how local governments assess their financial condition and fiscal health. Likewise, little is known about the types of financial indicators that local governments are utilizing. A systemic survey asking local practices of assessing financial condition and fiscal health are long overdue. It appears that unless state government requires their local government to regularly assess financial condition, not many local governments are likely toassess their own financial condition. It also demonstrates that local governments are not ready to assess their overall government-wide financial condition in the wake of the implementation of new financial reporting requirement.

Birth of an `Asian cool` reference genome: AK1

( Changhoon Kim ) 생화학분자생물학회(구 한국생화학분자생물학회) 2016 BMB Reports Vol.49 No.12

The human reference genome, maintained by the Genome Reference Consortium, is conceivably the most complete genome assembly ever, since its first construction. It has continually been improved by incorporating corrections made to the previous assemblies, thanks to various technological advances. Many currently-ongoing population sequencing projects have been based on this reference genome, heightening hopes of the development of useful medical applications of genomic information, thanks to the recent maturation of high-throughput sequencing technologies. However, just one reference genome does not fit all the populations across the globe, because of the large diversity in genomic structures and technical limitations inherent to short read sequencing methods. The recent success in de novo construction of the highly contiguous Asian diploid genome AK1, by combining single molecule technologies with routine sequencing data without resorting to traditional clone-by-clone sequencing and physical mapping, reveals the nature of genomic structure variation by detecting thousands of novel structural variations and by finally filling in some of the prior gaps which had persistently remained in the current human reference genome. Now it is expected that the AK1 genome, soon to be paired with more upcoming de novo assembled genomes, will provide a chance to explore what it is really like to use ancestry-specific reference genomes instead of hg19/hg38 for population genomics. This is a major step towards the furthering of genetically-based precision medicine. [BMB Reports 2016; 49(12): 653-654]

A Study on Differential User Authentication Scheme based on Client in Home Network

Changhoon Lee,Woongryul Jeon,Dongho Won 보안공학연구지원센터 2013 International Journal of Security and Its Applicat Vol.7 No.5

Principle of Emulsion PCR and Its Applications in Biotechnology

Changhoon Chai 한국동물생명공학회(구 한국동물번식학회) 2019 Journal of Animal Reproduction and Biotechnology Vol.34 No.4

Emulsion polymerase chain reaction (PCR) is performed on compartmentalized DNA, allowing a large number of PCR reactions to be carried out in parallel. Emulsion PCR has unique advantages in DNA amplification. It can be applied in many molecular biological assays, especially those requiring highly sensitive and specific DNA amplification. This review discusses the principle of emulsion PCR and its applications in biotechnology. Related technologies are also discussed.