전기화학적 도금을 이용한 wrap-around 게이트 나노구조의 제작

안재현,홍수헌,강명길,황성우,Ahn, Jae-Hyun,Hong, Su-Heon,Kang, Myung-Gil,Hwang, Sung-Woo 한국전기전자학회 2009 전기전자학회논문지 Vol.13 No.2

To overcome short channel effects, wrap-around field effect transistors have drawn a great deal of attention for their superior electrostatic coupling between the channel and the surrounding gate electrode. In this paper, we introduce a bottom-up technique to fabricate a wrap-around field effect transistor using silicon nanowires as the conduction channel. Device fabrication was consisted mainly of electron-beam lithography, dielectrophoresis to accurately align the nanowires, and the formation of gate electrode using electrochemical deposition. The electrolyte for electrochemical deposition was made up of non-toxic organic-based solution and liquid nitrogen was used as a method of maintaining the shape of polymethyl methacrylate(PMMA) during the process of electrochemical deposition. Patterned PMMA can be used as a nano-template to produce wrap-around gate nano-structures. Wrap-around 전계효과 트랜지스터는 채널과 전극간의 커플링을 매우 커서 채널길이가 짧아지면서 생기는 단채널효과(short channel effect)를 개선시킬 수 있는 이유로 많은 관심을 불러왔다. 본 논문에서는 실리콘 나노와이어를 이용하여 상향식의 wrap-around 전계효과 트랜지스터(FET)의 제작 공정을 소개한다. 소자의 제작 공정은 크게 전자빔 리소그래피, 유전영동(dielectrophoresis)을 이용한 나노와이어의 효과적 정렬 그리고 게이트 전극의 전기 화학적 도금(electrochemical deposition)을 이용한 생성 등의 방법들로 이루어진다. 전기 화학적 도금을 위한 용액은 독성을 띄지 않는 유기물 용액을 사용하였다. 액체 질소를 이용하여 polymethyl methacrylate(PMMA)가 전기화학적 도금시 형태를 잃지 않게 함으로써, 패터닝된 PMMA가 wrap-around 게이트 나노구조를 제작하기 위한 나노 템플릿으로 사용될 수 있도록 하였다.

도시침수 대응 및 복구계획 수립 연구

안재현,김학열,유승혁,Ahn,Jae-Hyun,Kim,Hag-Yeol,Yoo,Seung-Hyuk 한국방재학회 2008 한국방재학회 학술발표대회논문집 Vol.2008 No.1

Response and recovery plan is necessary to protect against urban flood which can cause damage on property and human life. In this research, urban flood response and recovery plans were studied to improve an establishment method for local autonomous entities. The result of this research will be applied to make a manual for forming response and recovery plan in Korea.

골다공증 한약제제 임상시험 참여자의 골다공증 한의치료에 대한 인식 : 질적 연구

안재현,조예은,김지혜,이승훈,강중원,이재동,Ahn, Jae-hyun,Cho, Ye-eun,Kim, Ji-hye,Lee, Seung-hoon,Kang, Jung-won,Lee, Jae-dong 대한한방내과학회 2017 大韓韓方內科學會誌 Vol.38 No.2

Objective: This research aimed to understand patients' perceptions of Korean medicine treatment for osteoporosis in a clinical trial setting. Methods: Ten patients participating in a clinical trial of a herbal medicine drug for osteoporosis were invited to an interview. Data were collected by in-depth interviews and patient observations. This qualitative study adopted the case study research method, and within-case and cross-case analyses were conducted. Results: A model of the patients' osteoporosis management planning was derived from the study. The results showed that the patients' perceptions of osteoporosis were derived from their knowledge and experience during diagnosis and treatment of the condition. Two groups of patients were recognized: those who overlooked the importance of osteoporosis and those who recognized the importance of osteoporosis. Before making treatment decisions about osteoporosis, the patients evaluated the treatment options and weighed the advantages and disadvantages of each option. When evaluating their treatment, the patients combined their knowledge and experience of Korean and western medicine treatments. Their experience of participating in the clinical trial influenced the management planning of osteoporosis. Two major reasons for low compliance with osteoporosis treatment were ignorance of the disease and insufficient information provided by doctors. Conclusion: The results of this qualitative study pointed to four strategies that could be employed to improve accessibility to Korean medicine treatment for osteoporosis: the dissemination of comprehensive information on osteoporosis in the clinic and mass media, promotion of Korean medicine therapies for osteoporosis, management of clinical trial participants, and insurance coverage for Korean medicine.

갑상선 미세유두상암의 임상적 특성

안재현,최재영<SUP>1<.SUP>,박원서,송정윤,김용호,이상목,고석환,Jae Hyun Ahn,M.D.,Jae Young Choi,M.D.<SUP>1<.SUP>,Won Seo Park,M.D.,Jeong Yoon Song,M.D.,Yong Ho Kim,M.D.,Sang Mok Lee,M.D. and Suck Hwan Koh,M.D. 대한갑상선-내분비외과학회 2008 The Koreran journal of Endocrine Surgery Vol.8 No.2

<B>Purpose:</B> PTMC is defined as a papillary thyroid cancer smaller than 10 mm in its greatest diameter. It is the most common form of differentiated thyroid cancer and its prognosis is known to be very favorable. The aim of this study is to identify its biologic behavior and to formulate a reasonable therapeutic strategy for the treatment of PTMC. <B>Methods:</B> 379 patients with papillary thyroid cancer were analyzed. Each patient was diagnosed preoperatively or postoperatively and treated between Jan. 2000 and Dec. 2007. Among these patients, 143 had been identified as having PTMC (37.7%) with a mean tumor size of 0.72 cm in diameter. <B>Results:</B> There were no significant differences of the clinical characteristics such as gender, age, the operative methods, or multicentricity between the PTMC group and the non-PTMC group, except for LN metastases. Also, there were fewer symptoms of palpable neck mass and preoperative findings such as capsular invasion and microcalcification in the PTMC group. We performed unilateral lobectomy with or without central compartment neck node dissection for the early stage diseases, but for the later stages of disease we performed near-total or total thyroidectomy with routine central compartment neck node dissection. And for the patients with lateral node enlargement, we performed ipsilateral modified radical neck dissection (MRND). <B>Conclusion:</B> This study shows that PTMC is quite similar to conventional papillary thyroid cancer in its biological behavior, and we conclude that total thyroidectomy with central compartment neck node dissection is the proper therapeutic strategy to treat PTMC. However, further study is necessary for identifying the low-risk and high-risk patients with PTMC. <B>(Ko</B><B></B><B>rean J Endocrine Surg 2008;8:101-105)</B>

경쟁 기반 MAC에서의 반복적 톤 기반 경쟁 기법

안재현,윤정균,박세웅,Ahn, Jae-Hyun,Yun, Jeong-Kyun,Bahk, Sae-Woong 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.5A

IEEE 802.11의 DCF는 경쟁 기반 방식으로 폴링 기반 방식의 PCF에 비해 알고리즘이 단순하고 나쁘지 않은 성능을 보여주기 때문에 실질적으로 많이 쓰이고 있다. 하지만 DCF는 경쟁을 통하여 채널을 할당받기 때문에 데이터 전송 시에 다른 노드들과 충돌의 위험이 있다. 이러한 충돌을 줄이기 위해서 CSMA/CA의 충돌 회피 방식을 사용하지만 그 성능에는 한계가 있다. 본 논문에서는 이런 문제를 해결하기 위해 톤을 사용한 새로운 경쟁 기법 TAR(Tone-based Access scheme with Repetitive contention)를 제안한다. TAR에서는 데이터 전송 채널(data transmission channel)외에도 적은 구간의 경쟁 채널(contention channel)을 두어 데이터 전송과 경쟁을 병렬적으로 처리함으로써 기존의 CSMA/CA가 가지고 있는 충돌에 대한 문제를 줄이고자 하였다. 경쟁 기법의 큰 개념은 기존의 CSMA/CA 기법을 이용하지만 경쟁 채널이라는 개념을 도입하여 반복적인 경쟁을 통해 데이터 전송 채널에서의 충돌 확률을 크게 줄이는 장점이 있다. 제안한 TAR 기법은 모의실험을 통해 기존의 기법에 비해 크게 좋은 성능을 보임을 확인하였다. There are two coordination functions in IEEE 802.11 standard. One is PCF, polling based function, and the other is DCF, contention based function. DCF is simpler than PCF but the performance is similar with the latter. That's the reason why DCF is more popular than PCF. However, DCF has a risk of collision with other nodes in the network because the function is a distributed contention based one. CSMA/CA of DCF has collision avoidance algorithm in it, but the performance of avoidance algorithm has limitations. In this paper we proposed a new scheme called TAR(Tone-based Access scheme with Repetitive conention). In TAR, there is narrow contention-only channel other than original data transmitting channel, so that both a data transmission and the contention can be performed simultaneously. The TAR uses the same contention concept with the CSMA/CA, but it has the originality for the narrow contention channel and the repetitive contention scheme which greatly reduce the collision probability. We proved the performance of TAR by some simulations, and it showed good results.

화재 예방을 위한 태양광 접속반의 지능형 진단 시스템

안재현,양오,Ahn, Jae Hyun,Yang, Oh 한국반도체디스플레이기술학회 2021 반도체디스플레이기술학회지 Vol.20 No.3

To prevent accidents caused by changes in the surrounding environment or other factors, various protection facilities are installed at the photovoltaic connection module. The main causes of fire are sparks due to foreign substances inside the photovoltaic connection module through high temperature rise and dew condensation in the photovoltaic connection module, and fire due to heat from the power diode. The proposed method can predict the fire by measuring flame, carbon dioxide, carbon monoxide, temperature, humidity, input voltage, and current on the photovoltaic connection module, and when the fire conditions are reached, fire alarm and power off can be sent to managers and users in real time to prevent fire in advance.

초기 골 접촉이 없는 순수 티타늄 임프란트 주위 골의 치유반응

안재현,김흥중,박주철,한경윤,김병옥,Ahn, Jae-Hyun,Kim, Heung-Joong,Park, Joo-Cheol,Han, Kyung-Yoon,Kim, Byung-Ock 대한치주과학회 1999 Journal of Periodontal & Implant Science Vol.29 No.1

Primary fixation is one of the most important factor in establishing adequate osseointegration between implant and bone. To evaluate the initial healing response of bone around implants without primary bone contact, this study was designed to create considerable space between implant and bone in 5 mongrel dogs, about 1-year old. After 3 holes of 6.0mm in diameter were prepared at the femur neck of the dogs, commercially pure titanium thread type implants(STERI-$OSS^{(R)}$), 8mm in length and 3.8mm, 5.0mm and 6.0mm in diameter, were inserted. Implants were supported by only nonresorbable membrane($Teflon^{(R)}$), and the penetration of upper soft tissue into the gap was inhibited by it. The each implant was positioned in the center of the drilled hole. 9 implants with different diameters were inserted in 3 dogs for histologic observation, and 12 were inserted in 2 dogs for mobility test and removal torque test.Fluorescent dyes were injected in order of Doxycycline, Alizarin Red S, and Calcein at intervals of 2 weeks. At 4-, 8-, and 12-week after placement, 3 dogs were sacrificed for histologic observation, and at 8- and 12-week after placement, 2 dogs were sacrificed for mobility test using $Periotest^{(R)}$ (Simens AG, Bensheim, Germany) and torque test using Autograph AGS-1000D $series^{(R)}$(Japan). The result were as follows: 1. The wider the gap between bone and implant was, the less bone maturity was, and the later osseointegration was occurred. Trabecular direction of new bone around implant was changed from parallel to perpendicular to the implant, and the gap was filled with new bone, over time. 2. There was a decreasing tendency over time in the mobility of all implants, but the wider gap between bone and implant was, the smaller decrease of the mobility was. 3. There was a increasing tendency over time in the removal torque gauge of all implants, and the wider gap was, the smaller increase of the removal torque gauge was. The results suggest that osseointegration in case of implant without primary bone contact may be obtained by guided bone regeneration technique with prolonged healing period, but the time of second surgery should be considered carefully.

다이오드 레이저를 이용한 광흡수 농도 계측 기법(Ⅰ)

안재현(Jae-Hyun Ahn),김용모(Yong-Mo Kim),김세원(Se-Won Kim) 한국연소학회 2004 한국연소학회지 Vol.9 No.3

과산화수소가 배합된 제제의 치아미백효과에 관한 연구

안재현 ( Jae Hyun Ahn ),김지혜 ( Ji Hye Kim ),김종훈 ( Jong Hoon Kim ),장종화 ( Jong Hwa Jang ),오윤종 ( Yoon Jong Oh ),박용덕 ( Yong Duk Park ) 한국치위생학회(구 한국치위생교육학회) 2014 한국치위생학회지 Vol.14 No.1

Objectives: The purpose of this study was to evaluate the tooth whitening effect of 0.74% and 2.80% hydrogen peroxide toothpastes and safety on tooth and gingival tissue. Methods: Toothpastes containing 0.74% and 2.80% hydrogen peroxide were evaluated. In in-vitro test, some additives (sodium metaphosphate, sodium pyrophosphate and titanium dioxide) were added to the toothpastes. Hydroxyapatite specimens (HAPs) were made and stained using modified Stookey`s methods. HAPs were treated for 1 hour at shaking incubator and brushed for 1,000 times as 250 gF with each diluted toothpaste. Before and after color was measured by colorimeter. Using double blind method, 99 Korean with natural maxillary anterior teeth were selected and the initial brightness (baseline) was measured by SHADEEYE-EX. Based on this measurement they were crossly distributed into control group (0% hydrogen peroxide), test 1 (0.74% hydrogen peroxide) and test 2 (2.80% hydrogen peroxide). After 2 weeks, people of each group were provided toothpaste and told to use 3 times a day right after every meal for 3 minutes. The brightness of teeth was measured 3 times for every one month. Results: ΔL was statistically significant among three groups in shaking test. ΔL of twotest groups was statistically significant compared with control group but not between each test group in brushing test. After using toothpaste for 3 months, test 1 group and test 2 group were 15.89% and 31.23% more whitened compared with control group respectively (p<0.05). Rate of more whitened person of each test group was 24.2% and 40.5% more than control group respectively (p<0.05). There was no difference in the hypersensitivity during 3 months using toothpastes and no side effect on teeth or gums. Conclusions: Toothpastes containing 0.74% and 2.80% hydrogen peroxide showed tooth whitening effect and both were safe enough to use for tooth whitening.

물수지 방정식을 이용한 댐 건설에 따른 수문환경의 변화 분석

안재현(Ahn Jae Hyun),유철상(Yoo Chulsang),박무종(Park Moo Jong),윤용남(Yoon Yong Nam) 대한토목학회 2000 대한토목학회 학술발표회 논문집 Vol.2000 No.3