카본 에어로겔을 이용한 초고용량 커패시터의 전기적 특성

한정우,이경민,이두희,이상원,윤중락,Han, Jeong-Woo,Lee, Kyeong-Min,Lee, Du-Hee,Lee, Sang-Won,Yoon, Jung-Rag 한국전기전자재료학회 2010 전기전자재료학회논문지 Vol.23 No.8

Carbon aerogels are promising materials as electrodes for electrical double layer capacitors (EDLCs). An optimum process is presented for synthesis of nanoporous carbon aerogels via pyrolyzing resorcinol-formaldehyde (RF) organic aerogels, which could be cost-effectively manufactured from RF wet gels. The major reactions between resorcinol and formaldehyde include an addition reaction to form hydroxymethyl derivatives ($-CH_2OH$), and then a condensation reaction of the hydroxymethyl derivatives ($-CH_2-$)- and methylene ether ($-CH_2OCH_2-$) bridged compounds. The textural properties of carbon aerogels obtained were characterized by nitrogen adsorption/desorption analysis and SEM and TEM. The application of the resultant carbon for electrodes of electric double layers capacitor (EDLC) in organic TEABF4/ACN electrolyte indicated that the ESR, as low as 55 $m{\Omega}$, was smaller than for commercially activated carbons. And EDLC with carbon Aerogel electrodes has an excellent stable more than for commercially activated carbons.

소아 중복 요관의 임상적 고찰

한정우,황대환,박지민,한상원,이재승,Han Jung-Woo,Hwang Dae-Hwan,Park Jee-Min,Han Sang-Won,Lee Jae-Seung 대한소아신장학회 2003 Childhood kidney diseases Vol.7 No.2

목적 : 중복 요관은 부검상 전인구의 0.9%에서 발견되는 비교적 흔한 비뇨기계 기형이다. 과거에는 발열, 복통, 혈뇨 등을 단서로 하여 발견되었으나, 최근에는 산전초음파에 의하여 조기 진단되고 있다. 저자들은 최근 5년간 본원에서 진단된 환아들의 임상 양상 및 산전초음파에 의한 조기 진단의 유용성에 대해 고찰하였다. 방법 : 1998년부터 2003년 7월까지 본원에 입원하여 진단된 18세 미만의 55례의 중복 요관 환아들을 대상으로 후향적 고찰을 시행하였다. 결과 : 진단 당시 평균 연령은 2.2세였고, 추적 기간의 평균은 14개월이었으며, 남녀비는 1:2.7이었다. 완전 중복 요관은 49례(89%)였다. 발열을 주소로 내원한 경우는 15례(27%)였고, 산전 진찰로 진단된 경우는 26례(47%)였다. 방광요관역류가 동반된 경우는 14례(28%)였고, 수신증은43례(88%)에서 동반되었다. 산전 진찰을 통해 진단된 군과 생후에 진단된 군의 비교시, DMSA 신주사상 결손의 비율은 각각 70.8%와 67.7%였으며, 환측 신장의 동위원소 섭취율은 각각 48.2%와 45.5%로 두 군간에 통계학적인 차이는 없었다. 결론 : 과거와 달리 최근 5년간 산전초음파로 중복 요관이 진단되는 비율은 47%로 증가하고 있으며, 이에 따라 진단시 연령이 낮아져(2.2세) 경과 추적이 조기에 시작될 수 있었다. 그 외의 임상적인 양상은 과거와 유사하였다. 산전초음파로 진단된 경우와 생후에 진단된 경우를 비교할 때, 두 군간에 신손상의 차이에 대한 통계적학적 유의성은 발견하지 못하였다. 산전 초음파가 조기 진단과 이에 따른 추적 관찰을 통해 치료시기를 적절히 결정하는 데에 도움이 될 것인지 알아보기 위하여 향후 광범위한 다기관 연구가 필요하다. Purpose : Ureteral duplication is a common urologic anomaly and early diagnosis may prevent irreversible renal damage. We thus aimed to evaluate the benefits of prenatal sonography in early detection. Methods : We retrospectively studied 55 children with duplicated systems who were admitted to Severance Hospital, Yonsei University, Seoul, Korea from January 1998 to July 2003. Results : The mean age at diagnosis was 2.3 years old. 89% of the children had complete duplicated ureter. 47% of the children visited the hospital with an initial complaint of abnormal prenatal sonographic findings. Among these patients, 70.8% had DMSA defects. The mean differential renal function(DRF) in the DMSA scan was 48.2% in the group diagnosed prenatally. In the postnatally-diagnosed group, DMSA defects were found in 67.7% patients and the mean DRF was 45.5%. Conclusion : In comparison with the past studies, the mean age at diagnosis is becoming younger, and the proportion of abnormal prenatal sonography as an initial complaint larger. Other clinical manifestations were similar. The difference of the renal damage between the prenatally diagnosed group and the postnatally diagnosed group was not statistically significant. A multi-center study may help to prove the importance of prenatal sonography in early diagnosis and treatment of ureteral duplication. (J Korean Soc Pediatr Nephrol 2003;7:189-196)

동해에서 직접 수열 대역확산 수중음향통신 기법의 해상실험 결과

한정우,김기만,윤영중,문현욱,천승용,손권,Han, Jeong-Woo,Kim, Ki-Man,Yun, Yeong-Jung,Mun, Hyeon-Uk,Chun, Seung-Yong,Son, Kweon 한국음향학회 2012 韓國音響學會誌 Vol.31 No.7

대역확산 기법은 인접 심벌간의 간섭을 최소화 하고, 은밀성(LPI, Low Probability of Intercept)과 다중 접속기능을 제공할 수 있다. 본 논문에서는 동해에서 직접수열 방식의 대역확산 기법으로 신호를 전송하고, 왜곡된 수신신호를 보상하기 위해 반송파와 시간 동기 복원 및 등화기를 적용한 결과를 나타낸다. 해상실험을 수행한 결과 송수신기사이의 거리가 3 km이었을 때 일반적인 QPSK(Quadrature Phase Shift Keying) 기법의 경우 $1.46{\times}10^{-2}$의 비트 오류율을 보였으며, 대역확산기법이 적용된 경우 $5.17{\times}10^{-4}$ 비트 오류율을 보였다. Spread spectrum provides the minimized inter-symbol interference, the low probability of intercept and the multiple access capability. This paper presents a direct sequence spread spectrum with carrier/timing recovery and equalizer which compensates the delay spread caused by multipath transmission. When the sea trials were performed in Korean East Sea, the bit error rates of QPSK and direct sequence spread spectrum are $1.46{\times}10^{-2}$ and $5.17{\times}10^{-4}$ at 3 km source-receiver range, respectively.

수중통신에서 클리핑 기법을 적용한 OFDM 시스템 연구

한정우,김세영,김기만,정지원,김승주,천승용,손권,도경철,Han, Jeong-Woo,Kim, Se-Young,Kim, Ki-Man,Jung, Ji-Won,Kim, Seung-Joo,Chun, Seung-Yong,Son, Kwon,Dho, Kyoung-Cheol 한국음향학회 2009 韓國音響學會誌 Vol.28 No.5

최근 수중 음향 통신의 필요성과 음성 및 고해상도 영상 데이터와 같은 다양한 데이터 전송의 요구가 증가되고 있다. 수중 음향 통신 시스템의 성능은 수중채널의 특성에 영향을 받으며, 특히 잔향 및 다중경로 (Multi-path)로 인한 지연확산은 데이터 전송 시 인접심벌간의 간섭 (Inter Symbol Interference : ISI)을 발생시켜 통신의 성능을 저하시킨다. 본 논문에서는 수중 채널에서 지연 확산에 강한 성능을 나타내는 OFDM (Orthogonal Frequency Division Multiplexing) 기법을 연구하였다. 또한 PAPR (Peak-to-Average Power Ratio)이 높은 경우 발생하는 성능저하를 극복하기 위해 클리핑 기법을 적용하였다. 실제 수중 채널을 모의하는 모델 및 수조에서의 실험을 이용하여 수중 음향 통신의 성능을 확인하였다. 그 결과 클리핑 기법을 이용한 다중 반송파가 가장 낮은 비트 오차율을 나타내였으며, 단일 반송파를 이용한 전송이 가장 높은 비트 오차율을 나타내었다. Recently, the necessity of underwater acoustic communication and demand for transmitting and receiving various data such as voice or high resolution image data are increasing as well. The performance of underwater acoustic communication system is influenced by underwater channel characteristic. Especially, a delay spread caused by reverberation and multi-path induces the ISI (Inter-Symbol-Interference) and reduces the communication performance. In this paper, we study the OFDM (Orthogonal Frequency Division Multiplexing) technique for robust the delay spread in underwater channel. We also use the clipping method to overcome the performance degradation in high PAPR (Peak-to-Average Power Ratio). We confirm the performances of underwater communication system by the underwater channel model simulation model and experiment in small water tank. As a result, the multi-carrier modulation with clipping method presented low BER and the previous single carrier modulation had high BER.

임베디드 커패시터용 세라믹(BaTiO₃)-고분자(에폭시) 필름의 세라믹 분말 형상 및 함량에 따른 전기적 특성

한정우,윤중락,제해준,이동호,이경민,Han, Jeong-Woo,Yoon, Jung-Rag,Je, Hae-June,Lee, Dong-Ho,Lee, Kyung-Min 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.6

The ceramic($BaTiO_3$)-polymer(epoxy) composites have been widely investigated as dielectric materials for embedded capacitors in printed circuit boards (PCBs). The dielectric properties of $BaTiO_3$/epoxy composites prepared using the agglomerated $BaTiO_3$ particles were investigated in the present study. The dielectric constants of the composites prepared using the agglomerated $BaTiO_3$ particles were about 2 times higher than those of the composites with the dispersed $BaTiO_3$ particles. The insulation resistance of the composites prepared using the agglomerated $BaTiO_3$ particles were lower than those of the composites with dispersed $BaTiO_3$ particles. As a result, there is tradeoff between high dielectric constant and insulation resistance in the $BaTiO_3$/epoxy composites. So it is important to select proper agglomerated or dispersed $BaTiO_3$ particles in accordance with needs.

과잉 간극 수압 모형 개발 및 적용

한정우,이승찬,박두희,Han. Jung-Woo,Lee. Seung-Chan,Park. Du-Hee 한국방재학회 2007 한국방재학회 학술발표대회논문집 Vol.2007 No.1

High excess pore water pressure may develop when loose saturated sand is subjected to earthquake excitation, resulting in reduction in the shear strength and stiffness, and ultimately can result in liquefaction. It is very important to accurately assess the level of the pore pressure generation for seismic design and to perform effective stress analysis. A simple numerical 모형 is developed for estimating the development of pore water pressure due to seismic loading. The method only uses two parameters and the length of the accumulated shear strain. The accuracy of the proposed 모형 is verified through a series of laboratory test data. Comparisons show that the modified 모형 is an improvement over existing 모형s.

수종(數種)의 한약재(韓藥材)와 보골탕(補骨湯)이 흰쥐의 실험적(實驗的) 골다공증(骨多孔症)에 미치는 영향(影響)

한정우,육태한,Han Jung-Woo,Yook Tae-Han 대한침구의학회 2001 대한침구의학회지 Vol.18 No.6

Objective : The purpose of this studies was to determine the effect of Carthami semen, Bogol-Tang and Rhynchosia volubilis Lour. on changes of trabecular area and physiological metabolites in the ovariectomized osteoporotic Rats. Methods : In order to induce estrogen deficient osteoporosis, ovariectomy was done on rats. Then the Carthami semen, Bogol-Tang and Rhynchosia volubilis Lour. were orally administerd: Such indexes were measured as the changes of body weight, bone mineral density, trabecular area in tibia, and levels of osteocalcin, bone alkaline phosphatase, calcium, phosphorus, cholesterol, triglyceride, aspartate aminotransferase and alanine aminotransferase in serum. Results : 1. The change of bone mineral density in Bogol-Tang group and Rhynchosia volubilis lour. group. was significantly increased compare to control group. 2. The change of trabecular area % in epiphysis of tibia in Carthami semen group was significantly increased compare to control group. 3. The change of trabecular area % in diaphysis of tibia in Bogol-Tang group was significantly increased compare to control group. 4. The change of serum osteocalcin in Bogol-Tang group was significantly decreased compare to control group. 5. The change of serum bone alkaline phosphatase in Bogol-Tang group was significantly decreased compare to control group. 5. The change of serum bone alkaline phosphatase in Bogol-Tang group was significantly decreased compare to control group. 6. The change of1 serum calcium in Rhynchosia volubilis lour. group was significantly decreased compare to control group. 7. The change of phosphorus in Carthami semen group and Rhynchosia volubilis Lour. group was significantly decreased compare to control group. 8. The change of serum cholesterol and triglyceride of experimental groups were decreased in comparison with control group. 9. The change of serum AST(Aspartate aminotransferase : GOT) in Rhynchosia volubilis Lour. group was decreased compare to control group. 10. The change of serum ALT(Alanine aminotransferase : GPT) in Bogol-Tang group was decreased compare to control group.

교정 치료를 받지 않은 측두하악관절원반변위가 있는 여성 환자의 두부계측방사선사진을 이용한 안모 및 치열 변화 연구

한정우(Jung-Woo Han),김태우(Tae-Woo Kim) 대한치과교정학회 2010 대한치과교정학회지 Vol.40 No.6

관절원반변위가 있는 여자 환자 중 초진 시와 일정 시간이 지난 기간 동안 교정 치료를 비롯한 교합에 변화를 줄 만한 치료를 받지 않은 여성 환자를 대상으로 두 시기의 측모두부계측방사선 사진을 비교하여 골격 및 치성 변화를 관찰할 목적으로 시행되었다. 1996년 1월부터 2006년 12월 사이에 서울대학교 치과병원 치과교정과에 내원한 여자환자 중 MRI를 촬영하여 관절원반변위가 있는 환자를 선별하였으며, 총 25명의 환자를 대상으로 연구를 하였다. 초진(T1) 시의 환자의 평균 연령(표준편차)은 18.1세(3.5세)이며 연령의 범위는 14.2 - 25.8세이고, 재진(T2)시 평균 연령(표준편차)은 21.1세(3.5세)이며 연령의 범위는 16.2 - 28.0세였다. 또한 평균 관찰 기간(표준편차)은 3.0년(1.9년)이었고 범위는 7개월부터 6.7년이었다. 초진(T1), 재진(T2) 시와 두 기간 사이 변화량에 대한 각 변수의 기술 통계량을 계산하였다. 이상의 결과로부터 다음과 같은 결론을 얻었다. MRI로 관절원반변위를 진단받은 환자 중 교정치료나 악관절 치료 등 교합에 변화를 줄 만한 치료를 받지 않은 환자의 약 64%에서 하악골의 골격적인 변화가 나타났다. L1 to Mandibular plane은 0.8 mm 유의성 있게 증가하였다 (p < 0.01). 그러나 이를 제외한 나머지 치성 계측 항목인 전치돌출도, 전치피개도 및 U1 to Palatal plane (mm)의 변화는 유의성이 없었다. 변화의 방향은 주로 하악의 후하방회전이었고, 그 비율은 FMA가 1˚ 증가 시 SNB는 약 0.43˚ 감소하는 정도였다 (Spearman"s rho = ?0.660, p < 0.01). 일부 환자들은 수평적인 하악골의 후방 양상 이동을 보이기도 하였다. (대치교정지 2010;40(6):398-410) Objective: The purpose of this study was to investigate the changes in dentofacial morphology of non-orthodontically treated female patients with TMJ disk displacement. Methods: The sample consisted of 25 Korean female patients with bilateral TMJ disk displacement who visited the Department of Orthodontics, Seoul National University Dental Hospital from 1996 to 2006. Disk displacements were diagnosed using the magnetic resonance imaging (MRI) of both TMJs. Baseline (T1) and follow-up (T2) lateral cephalograms were analyzed. The mean age of samples at T1 was 18.1 ± 3.5 years (range 14.2 - 25.8 years) and at T2, 21.1 ± 3.5 years (range 16.2 - 28.0 years). The mean observation period was 3.0 ± 1.9 years. Descriptive statistics for each variable were calculated at baseline (T1) and follow-up (T2) stages, and during the observation period (T2-T1). Results: Skeletal changes were found in 64% of the non-orthodontically treated female patients with TMJ disk displacement during the observation period. The L1 to Mandibular plane distance (mm) increased significantly by 0.8 mm (p < 0.01). But there were no significant differences in the other dental relationship variables (overjet, overbite, U1 to palatal plane) during the observation period. Most patients with skeletal changes showed a backward rotation of the mandible. The ratio of the rotation was a decrease of SNB by 0.43˚ for every 1˚ increase of FMA (Spearman rho = ?0.660, p < 0.01). A few patients showed a distal shift of the mandible without rotation or significant changes in the vertical dimension. Conclusions: During observation periods without orthodontic treatment, non-growing patients with TMJ disk displacement showed dentoskeletal changes, mainly backward rotation of the mandible. (Korean J Orthod 2010;40(6):398-410)

Polyorganosiloxane 변성 폴리우레탄의 유변 특성

한정우(Jung Woo Han),한미선(Mi Sun Han),이상문(Sang Moon Lee),박태석(Tae Suk Park),강두환(Doo Whan Kang),강호종(Ho Jong Kang) 한국고분자학회 2002 폴리머 Vol.26 No.5

Point-based Method 를 사용한 포인트 클라우드 연구 동향

한정우 ( Jung-woo Han ),김종국 ( Jong-kook Kim ) 한국정보처리학회 2021 한국정보처리학회 학술대회논문집 Vol.28 No.2

In recent years, the use of LiDAR sensors is increasing as autonomous driving, robot control, and drones are considered more. Contrary to ordinary cameras, LiDAR sensors make it possible to handle challenging problems by calculating the distance between objects. This crucial characteristic makes more active research on deep learning models dealing with point clouds which are data of LiDAR. In this paper, among the schemes of using the point cloud, the Point-based approach is mainly discussed. Furthermore, future streams and insights can be considered by looking at solving methods and the limitations.