그래핀에 담지된 Fe₃O₄와 CuO 나노입자의 리튬이차전지 음극성능

정재훈,정동원,한상욱,김광현,오은석,Jeong, Jae-Hun,Jung, Dong-Won,Han, Sang-Wook,Kim, Kwang-Hyun,Oh, Eun-Suok 한국전기화학회 2011 한국전기화학회지 Vol.14 No.4

본 연구에서는 에틸렌글리콜을 사용한 polyol reduction 방법으로 나노크기의 $Fe_3O_4$와 CuO가 각각 그래핀에 분산된 $Fe_3O_4$/graphene, CuO/graphene 복합체를 합성하였으며, 이를 리튬이차전지의 음극활물질로 사용한 전극의 성능을 평가하였다. 합성된 복합체의 물리적 특성은 SEM, XRD, TGA 등으로 분석하였으며, 반쪽전지를 제조하여 충/방전, cyclic voltammetry, 교류 임피던스 등의 전기화학적 특성평가를 수행하였다. 그래핀 표면에 분산된 금속산화물 나노입자들에 의한 용량증가 및 전기적 네트워크 향상 등의 효과로 $Fe_3O_4$/graphene 및 CuO/graphene 복합체의 전극성능이 그래핀 전극보다 우수하였다. 복합체의 경우 30회 충/방전 후에도 600 mAh/g 용량을 유지하였다. In this study, $Fe_3O_4$/graphene and CuO/graphene composites were synthesized by the polyol reduction method using ethylene glycol, and their performances as the anodes of lithium ion batteries were evaluated. The physical characteristics of the synthesized composites were analyzed by SEM, XRD, and TGA. In addition, their electrochemical properties were examined by the electrochemical analysis techniques such as charge/discharge performance, cyclic voltammetry, and AC impedance spectroscopy. The cells composed of $Fe_3O_4$/graphene and CuO/graphene composites showed better performance than the graphene electrode, due to the dispersion of nanosized $Fe_3O_4$ or CuO on the surface of graphene and the formation of good electrical network in the electrode. Their composites kept the reversible capacity more than 600 mAh/g even after the charging/discharging of 30 cycles.

갑상설관낭종에서 발생한 유두상암종 4예

정재훈,한명월,노종렬,최승호,김상윤,남순열,Jung, Jae Hoon,Han, Myung Woul,Roh, Jong-Lyel,Choi, Seung-Ho,Kim, Sang Yoon,Nam, Soon Yuhl 대한기관식도과학회 2012 大韓氣管食道科學會誌 Vol.18 No.1

Carcinoma arising in a thyroglossal duct cyst is a not common disease. It is detected in approximately 1% of thyroglossal duct cyst, therefore the clinical manifestation of the patient with carcinoma is undistinguishable from the common cystic lesion. Clinically, it may be confounded with a benign lesion and diagnosed after operation. The mainstream of treatment is the Sistrunk operation, however, there is no definite agreement regarding further treatment in addition to an excision of the cyst. The role of total thyroidectomy and the radioactive iodine therapy have been discussed for adjuvant treatment. We have experienced four cases of papillary carcinoma arising in thyroglossal duct cyst. In the three of the cases, the patients underwent Sistrunk operation, while the other one had additional total thyroidectomy and postoperative radioactive iodine therapy. There was no complication in the perioperative period and no signs of recurrence or metastasis during follow-up period.

고차 다층구조 신경회로망을 이용한 LCD 모니터의 색 보정

정재훈,이동욱,안강식,조석제,Jung, Jae-Hoon,Lee, Dong-Wook,Ahn, Kang-Sic,Cho, Seok-Je 한국정보처리학회 2004 정보처리학회논문지B Vol.11 No.2

본 논문에서는 고차 다층구조 신경회로망을 이용한 LCD 모니터의 색 보정 방법에 관하여 제안하였다. LCD 모니터는 다양한 디스플레이 시스템 구성요소로 인해 비선형적인 특성을 지닌다. 이러한 비선형적 특성들을 해결하고 양질의 영상을 나타내기 위해서는 LCD 모니터좌표와 입력되는 색 자극치 사이의 비선형 색 좌표변환이 필요하다. 고차 다층구조 신경회로망은 학습을 통해 입력되는 색 자극치를 효과적으로 모니터에 가상한다. 실험을 통해 제안한 방법이 칼라 영상의 재현에 효과적임을 확인하였다. This paper presents a new color correction method for color reproduction on LCD-based monitor by means of high-order multilayer neural networks. LCD monitors have nonlinear characteristics from various displaying system components. To overcome these nonlinearities and produce quality image, we need a nonlinear transformer for color coordinate transformation between the LCD monitor coordinates and the input color stimulus values. A high-order multilayer neural network is effectively trained to learn a mapping to determine the required color value of monitors for producing a given color stimulus. From the experimental results, the proposed method is effective in reproducing the color images.

THEODOLITE로 측정한 14 m 전파망원경의 주경면 모양

정재훈,김현구,김태성,정현수,박용선,Jung, Jae-Hoon,Kim, Hyun-Goo,Kim, Tai-Seong,Chung, Hyun-Soo,Park, Yong-Sun 한국천문학회 1997 天文學論叢 Vol.12 No.1

In order to reduce the small scale fluctuation resulting from shearing holograpy(Park et. al. 1997), differential panel adjustments were performed for 14 m radio telescope of Taeduk Radio Astronomy Observatory with T2 theodolite It appears that this method improves the surface accuracy by about $50\;{\mu}m$. The measured surface accuracy is, at best, $170\;{\mu}m$. The beam efficiency at 86.2 GHz is estimated to be 44% We also found that the elevation at which Park et. al. performed holography was too low.

안와 상벽 골절과 광대뼈 골절의 임상 양상과 치료 및 동반된 안과적 진단

정재훈,이화,이종미,백세현,Jae Hoon Jung,Hwa Lee,Jongmi Lee,Sehyun Baek 대한안과학회 2012 대한안과학회지 Vol.53 No.4

Purpose: To investigate the clinical manifestations, management, and ophthalmologic complications of orbital roof fractures and zygoma fractures. Methods: A retrospective survey of 119 patients who visited Korea University Medical Center from June 2009 to June 2010 was performed. The sex, age, causes, fracture characteristics, neurologic injury, ocular injury, and combined facial bone fractures of patients who were diagnosed with orbital roof fracture and zygoma fracture were statistically analyzed. Results: The mean age of patients with orbital roof fracture was 33.0 years old. The most common cause of orbital roof fracture was traffic accident (36.1%) with 6 patients receiveing surgical treatement (9.8%). Among the ophthalmologic diagnoses of the patients with orbital roof fracture, traumatic iridocyclitis was the most common (7 eyes) followed by eyeball rupture (2 eyes). The mean age of patients with zygoma fracture was 36.6 years old. The most common cause of zygoma fracture was traffic accident (32.8%), with 51 patients receiving surgical treatement (87.9%). Among the ophthalmologic diagnoses of the patients with zygoma fracture, traumatic iridocyclitis was the most common (6 eyes), followed by commotio retina (4 eyes). Conclusions: The present study regarding clinical characteristics and treatment of orbital roof fracture and zygoma fracture is helpful for ophthalmologists regarding the treatment of accompanying ophthalmologic complications. J Korean Ophthalmol Soc 2012;53(4):577-581

단일 광섬유 브래그 격자와 EDFA를 이용한 온도와 스트레인의 동시 측정

정재훈,남희,이병호,Jung, Jae-Hoon,Nam, Hui,Lee, Byoung-Ho 대한전자공학회 1999 電子工學會論文誌, D Vol.d36 No.6

We propose and demonstrate a novel sensor which can simultaneously measure strain and temperature. The sensor is composed of a single fiber Bragg grating and an erbium-doped fiber amplifier. Using linear variation in the amplified spontaneous emission power of an erbium-doped fiber amplifier with temperature, we determine the temperature. By subtracting the temperature effect from the Bragg wavelength shift, we determine the strain. Experiments show rms deviations of $18.2{\mu}{\varepsilon}$ and $0.7^{\circ}C$ for strain and temperature, respectively. 하나의 광섬유 브래그 격자와 EDFA를 이용하여 온도와 스트레인을 동시에 측정할 수 있는 센서를 제안하고 구현하였다. 혼도에 따른 EDFA 의 ASE파워의 선형적 변화를 이용하여 온도를 측정하고 전체 브래그 파장변화와 그 온도효과의 차로써 스트레인을 측정하였다. 측정값은 스트레인과 온도 각각에 대해서 $18.2{\mu}{\varepsilon}$과 $0.7^{\circ}C$의 rms 오차를 가진다.

조절 가능한 온도감도를 지닌 광섬유격자 온도센서

정재훈,남희,이병호,Jung, Jae-Hoon,Nam, Hui,Lee, Byoung-Ho 대한전자공학회 1999 電子工學會論文誌, D Vol.d36 No.9

온도 팽창률이 다른 두 개의 금속을 광섬유 브래그 격자에 부착하여 그 온도감도를 조절할 수 있는 새로운 온도센서를 제안하였다. 이러한 방법으로 온도감도를 기존의 브래그격자에 비해 3.3까지 향상시켰으며 금속의 길이를 변화시켜 그 온도감도를 여러 가지로 조절할 수 있었다. By attaching two metals with different thermal expansion coefficients to a fiber Bragg grating, we show that the temperature sensitivity is successfully improved to 3.3 times that of bare fiber Bragg grating and controlled by changing the metal length.

Simultaneous Measurement of Strain and Temperature by use of Fiber Bragg Grating Written in an Erbium: Ytterbium-Doped Fiber

정재훈,Jung, Jae-Hoon Institute of Korean Electrical and Electronics Eng 2004 전기전자학회논문지 Vol.8 No.1

단일 광섬유 격자와 Yb와 Er이 첨가된 광섬유를 이용한 스트레인 및 온도의 동시 측정을 시행하였다. 스트레인과 온도에 대해서 $1100\;{\mu}{\varepsilon}$ and $50-180\;^{\circ}C$ 범위에서 $55.8\;{\mu}{\varepsilon}$ 와 $3\;^{\circ}C$의 오차를 가지고 측정하였다. 본 센서의 소형 및 저가의 특성으로 미루어 볼 때 넓은 범위의 스트레인 센서로 활용가치가 높다고 사료된다. We demonstrate a fiber-optic sensor scheme, capable of the simultaneous measurement of strain and temperature using a single fiber Bragg grating written in an erbium: ytterbium-doped fiber. This novel and compact fiber grating based sensor scheme can be used for synchronous measurement of strain and temperature over ranges of $1100\;{\mu}{\varepsilon}$ and $50-180\;^{\circ}C$ with rms errors of $55.8\;{\mu}{\varepsilon}$ and $3^{\circ}C$, respectively. The simple and low-cost sensor approach has a considerable potential, particularly for wide-range strain sensing applications in which high resolution is not required.

플라스틱 기판을 이용한 고분자 청색 유기발광다이오드의 발광 특성

정재훈,문대규,Jung, Jae-Hoon,Moon, Dae-Gyu 한국전기전자재료학회 2013 전기전자재료학회논문지 Vol.26 No.9

We have fabricated blue phosphorescent organic light-emitting devices (OLEDs) on a plastic substrate. The solution coated poly (9-vinylcarbazole) (PVK) host doped with Bis (3,5-difluoro-2-(2-pyridyl)phenyl_(2-carboxypyridyl)irdium(III) (FIrPic) guest molecules was used as an hole transporting emission layer. The device structure was ITO/PVK:FIrpic (50 nm, xwt%)/TAZ 50 nm)/LiF (0.5 nm)/Al (100 nm). The concentration of FIrpic molecule was varied from 1 wt% to 10 wt%. The OLED on plastic substrate exhibited maximum current efficiency of 18 cd/A with 5 wt% FIrpic molecules were doped into the PVK layer.

준공 BIM 구축을 위한 Graph-based SLAM 기반의 실내공간 3차원 지도화 연구

정재훈,윤상현,허준,Jung, Jaehoon,Yoon, Sanghyun,Cyrill, Stachniss,Heo, Joon 한국건설관리학회 2016 한국건설관리학회 논문집 Vol.17 No.3

현재 국내 대부분의 토목 건축 구조물이 BIM 정보가 부재한 상황에서 준공 BIM(as-built BIM)의 수요가 점차 증가하고 있다. 준공 BIM 구축을 위한 공간자료 취득에는 고밀도의 포인트 클라우드를 생성할 수 있는 레이저 스캐너가 주로 활용되고 있다. 하지만 기존의 고정식 스캔 시스템은 이동이 번거롭고, 정밀한 위치 선정이 필요 하며, 스캔 자료 정합을 위해 별도의 표지를 설치하거나 공액점을 추출하는 과정이 필요하다. 본 연구에서는 수작업을 최소화하기 위해 기존의 고정식 스캔 시스템을 대체할 수 있는 이동식 스캔 시스템을 제안하고자 하며, 기반 기술로 graph-based SLAM을 적용하였다. 테스트 장비는 총 세 개의 2차원 스캐너를 탑재하고 있으며, 중앙의 한 개는 수평으로 설치되어 graph 구축을 통한 이동경로취득에 사용되었고, 좌우 두 개는 수직으로 설치되어 시스템 진행의 연직 방향으로 주변 구조물에 대한 3차원 스캔 정보 취득에 사용되었다. 개발된 graph-based SLAM은 이동경로 상에 누적된 위치오차를 해소하기 위한 loop closure 처리 방법으로 Adaboost 기계학습을 적용하였다. 이는 특히 본 연구에서 사용한 장비와 같이 기계학습을 위한 다수의 feature 정보를 제공할 수 있는 멀티 스캐너 시스템에 적합한 방식이며, 두 실내공간을 대상으로 한 테스트에서 단일 스캐너 대비 false positive rate를 각각 7.9% 및 13.6%까지 줄일 수 있었다. 최종적으로 연구대상지역의 2차원 및 3차원 지도 구축을 통해 개발된 graph-based SLAM의 효용성을 확인하였다. In Korea, the absence of BIM use in existing civil structures and buildings is driving a demand for as-built BIM. As-built BIMs are often created using laser scanners that provide dense 3D point cloud data. Conventional static laser scanning approaches often suffer from limitations in their operability due to the difficulties in moving the equipment, the selection of scanning location, and the requirement of placing targets or extracting tie points for registration of each scanned point cloud. This paper aims at reducing the manual effort using a kinematic 3D laser scanning system based on graph-based simultaneous localization and mapping (SLAM) for continuous indoor mapping. The robotic platform carries three 2D laser scanners: the front scanner is mounted horizontally to compute the robot's trajectory and to build the SLAM graph; the other two scanners are mounted vertically to scan the profiles of surrounding environments. To reduce the accumulated error in the trajectory of the platform through loop closures, the graph-based SLAM system incorporates AdaBoost loop closure approach, which is particularly suitable for the developed multi-scanner system providing more features than the single-scanner system for training. We implemented the proposed method and evaluated it in two indoor test sites. Our experimental results show that the false positive rate was reduced by 13.6% and 7.9% for the two dataset. Finally, the 2D and 3D mapping results of the two test sites confirmed the effectiveness of the proposed graph-based SLAM.