WCDMA 시스템에서 극성 변조를 이용한 빠른 셀 탐색 알고리즘

임재성,배성오 한국통신학회 2002 韓國通信學會論文誌 Vol.27 No.8B

내산화성 초미립 Fe-Co분말 제조와 자기적 특성에 관한 연구

임재성,강신우,김영삼 동아대학교 공과대학부설 생산기술연구소 1998 生産技術硏究所硏究論文集 Vol.3 No.2

Ultra fine Fe-Co particle with oxidation resistance was produced by reducing the silica coated Co-ferrite particle with H_2 at 500℃. When the silica coated Co-ferrite particle was reduced in H_2 at 500℃ for 6 hrs, the silica coated Fe-Co particle(SiO_2/Fe-Co=3.6wt%) showed following properties, e.g, high oxidation resistance below 150℃ , magnetization value of 154.4 emu/g and the size range between 30 and 290Å(mean particle size of 94Å)

부분 폐색 영역의 GAN 기반 복원을 통한 효과적 얼굴인식 기법

임재성,홍충표 한국차세대컴퓨팅학회 2022 한국차세대컴퓨팅학회 논문지 Vol.18 No.5

In the vision-based object recognition, there are practically various limitations to always proceed with the identification based on the optimal image. For example, a part of the object may be occluded due to the presence of an object causing interference when acquiring an image of the object of interest. Even in the face classification of a person, if there is an occlusion such as a mask, there may be a problem that the accuracy is lowered when the classification is performed through the conventional trained model. To overcome this, we propose a pipeline that combines the GAN-based occlusion area restoration technique and the ArcFace Loss model, a machine learning algorithm based on the distance of the embedding vector, to increase the recognition accuracy of partially occluded faces. In this paper, the performance is evaluated based on the classification of a mask-wearing person, a representative example of an occluded face image. As a result, performance improvements of 68% and 0.62 were confirmed in Accuracy and F-1 Score, respectively, compared to conventional face learning. 비전 기반의 객체 인식에 있어 항상 최적의 영상을 기반으로 식별을 진행하기에는 현실적으로 다양한 제약이 존재한다. 예를 들어, 관심 객체의 영상획득 시 간섭을 일으키는 물체의 존재와 같은 이유로 인해 객체의 일부가 가려져 있을 수 있다. 인물의 얼굴 분류에 있어서도 마스크와 같은 폐색물이 존재할 경우 원래의 학습된 모델을 통한 분류 진행시 정확도가 떨어지는 문제가 발생할 수 있다. 이를 극복하기 위하여 GAN 기반의 폐색 영역 복원 기법 및 임베딩 벡터의 거리에 따른 학습 알고리즘인 ArcFace Loss 모델을 결합한 파이프라인을 제안해 부분 폐색된 얼굴의 인식률을 높이고자 한다. 본 논문에서는 폐색된 얼굴 이미지의 대표적인 예인 마스크 착용 인물의 학습 및 분류를 바탕으로 성능을 평가한다. 결과로 Accuracy와 F-1 Score에서 일반적인 얼굴 학습에 비하여 각기 68%와 0.62의 성능향상을 확인하였다.

전립선 비대증 진단에 있어서 전립선 이행대 용적 지수의 유용성

임재성,노안식,김용웅,육승모 충남대학교 의과대학 의학연구소 2003 충남의대잡지 Vol.30 No.1

Purpose : Prostate volume has been poorly correlated to various parameters used to assess benign prostatic hyperplasia (BPH), including symptom score, peak urine flow and detrusor pressure at peak urine flow. The purpose of this study was 2-fold: 1) to determine if transrectal ultrasound measurement of the transition zone of the prostate served as a better proxy for determining prostate size and correlated better with IPSS, peak urine flow and detrusor pressure and 2) if the parameter transition zone index (the ratio between transition zone volume and prostate volume) was useful in evaluating clinical prostatism. Materials and Methods: We prospectively evaluated 30 men with symptomatic BPH (mean age 65.4 years) according to symptom sore, peak urine flow, pressure/flow study, transrectal ultrasound volume of the entire prostate and the transition zone and calculation of the transition zone index. Results : There was a week correlation between prostate volume and symptom score, peak urine flow and detrusor pressure at peak urine flow: a stronger correlation between volume of transition zone and symptom score (r=0.679 p=0.03), and peak urine flow (r=-0.672 p=0.05) and a significant correlation (p=0.001) between transition zone index and symptom score (r=0.868), and peak urine flow(r=-0.870). Conclusion : Transition zone index is a parameter that correlates siginificantly with parameters of BPH and may serve as a useful proxy for evaluating worsening obstruction. Studies are underway to determine whether transtion zone index can be used prospectively to predict and correlate response with therapies designed to ablate prostatic tissue medically or surgically.

High-Performance Schottky Junction for Self-Powered, Ultrafast, Broadband Alternating Current Photodetector

임재성,KUMARMOHIT,서형탁 한국재료학회 2022 한국재료학회지 Vol.32 No.8

In this work, we developed silver nanowires and a silicon based Schottky junction and demonstrated ultrafast broadband photosensing behavior. The current device had a response speed that was ultrafast, with a rising time of 36 μs and a falling time of 382 μs, and it had a high level of repeatability across a broad spectrum of wavelengths (λ = 365 to 940 nm). Furthermore, it exhibited excellent responsivity of 60 mA/W and a significant detectivity of 3.5 × 1012 Jones at a λ = 940 nm with an intensity of 0.2 mW cm2 under zero bias operating voltage, which reflects a boost of 50%, by using the AC PV effect. This excellent broadband performance was caused by the photon-induced alternative photocurrent effect, which changed the way the optoelectronics work. This innovative approach will open a second door to the potential design of a broadband ultrafast device for use in cutting-edge optoelectronics.

계통 안정도 모의를 통한 전력계통의 무력화 방안

임재성,강현구,김택원,문승일,임완권,Lim, Jae-Sung,Kang, Hyun-Koo,Kim, Taek-Won,Moon, Seung-Il,Lim, Wan-Khun 한국군사과학기술학회 2009 한국군사과학기술학회지 Vol.12 No.4

When assailing some area, it is important to consider targeting power system. This paper describes effective method that power networks are incapacitated based on assessing TSI and VDI. For this, we compose realistic scenario and analyze the simulation results in a view of stability. The simulation results show the destruction effects when occur the contingency in the specified area. To perform this process, the simulation tool PSS/E and DSAT are used.

Organic Thin Film Transistors with Gate Dielectrics of Plasma Polymerized Styrene and Vinyl Acetate Thin Films

임재성,신백균,이붕주 한국전기전자재료학회 2015 Transactions on Electrical and Electronic Material Vol.16 No.2

Organic polymer dielectric thin films of styrene and vinyl acetate were prepared by the plasma polymerizationdeposition technique and applied for the fabrication of an organic thin film transistor device. The structural propertiesof the plasma polymerized thin films were characterized by Fourier-transform infrared spectroscopy, X-ray diffraction,atomic force microscopy, and contact angle measurement. Investigation of the electrical properties of the plasmapolymerized thin films was carried out by capacitance-voltage and current-voltage measurements. The organic thinfilm transistor device with gate dielectric of the plasma polymerized thin film revealed a low operation voltage of -10V and a low threshold voltage of -3 V. It was confirmed that plasma polymerized thin films of styrene and vinyl acetatecould be applied to functional organic thin film transistor devices as the gate dielectric.

GAN 마스크 제거 학습을 이용한 얼굴인식 기법

임재성,송민석,홍충표 한국차세대컴퓨팅학회 2022 한국차세대컴퓨팅학회 학술대회 Vol.2022 No.05

본 논문에서는 마스크를 착용한 얼굴 이미지에서 GAN을 통해 마스크를 제거한 이미지를 생성하고 신원을 확인하는 시스템을 제안한다. 이 시스템은 RetinaFace 모델을 이용하여 마스크를 착용한 얼굴을 탐지하고, 탐지된 얼굴의 마스크 영역을 GAN으로 생성한 다음, 생성한 얼굴을 ArcFace 모델로 임베딩 한다. 기존 데이터베이스에 등록된 얼굴과 GAN으로 생성한 얼굴의 임베딩 벡터 사이의 Angular Cosine Distance를 측정하여 동일 인물인지 판단하는 매칭 알고리즘을 제안한다.

전부요도손상환자에서 요도경하 일차적 요도정렬술의 임상적 고찰

임재성 충남대학교 의과대학 의학연구소 2003 충남의대잡지 Vol.30 No.1

Straddle injuries to the anterior urethra should always be managed by urinary diversion and delayed repair because the crush injury makes delineation of the healthy margin difficult. The trend towards primary urethral realignment may prevent the need for definitive urethroplasty in a these patients. Between May 2001 and Mar. 2003 among 7 patients with trauma of anterior urethra were treated by endoscopically guided primary urethra1 realignment. Of the 5 incomplete ruptures, 4 had excellent results without stricture from 3 months to 2 years. Then 1 had focal urethral stricture, which could be easily treated with visual internal urethrotomy. Of the 2 complete ruptures, focal urethral stricture, which could be easily treated with visual internal urethrotomy. Complications including acute pyelonephritis and urinary tract infection were seen in one patients respectively. Endoscopically guided primary urethral realignment offers more simple and effective than delayed repair.

(+-)-Ondansetron 합성연구

임재성,박규순 국민대학교 2001 기초과학연구소 논문집 Vol.20 No.-