Magnetic resonance electrical properties tomography for small anomalies using boundary conditions: A simulation study

Lee, Joonsung,Choi, Narae,Seo, Jin Keun,Kim, Dong-Hyun Published for the American Association of Physicis 2017 Medical physics Vol.44 No.9

<P>Conclusions: The proposed reconstruction method not only determines electrical properties, but also circularly polarized component and longitudinal component of electric fields using an iterative process. The proposed method can quantitatively detect the conductivity of the small anomalies better than conventional methods. (C) 2017 American Association of Physicists in Medicine</P>

AI Basis Massive MIMO Performance Optimization

Joonsung Lee(이준성) 한국통신학회 2021 한국통신학회 학술대회논문집 Vol.2021 No.6

Massive MMO has become a key technology component in 5G networks for improving spectral efficiency, data rates and network coverage. Massive MIMO brings also new challenges and requires a set of new solutions for the mass market. This thesis illustrates Artificial Intelligence basis Massive MIMO beamforming optimization process and performance results. Improved spectral efficiency characteristics of the proposed method in comparison with the conventional methods are demonstrated through computer simulations to support the proposed method.

Determination of Optimal Scan Time for the Measurement of Downstream Metabolites in Hyperpolarized ¹³C MRSI

Lee, Hansol,Lee, Joonsung,Joe, Eunhae,Yang, Seungwook,Choi, Young-suk,Wang, Eunkyung,Song, Ho-Taek,Kim, Dong-Hyun Korean Society of Magnetic Resonance in Medicine 2015 Investigative Magnetic Resonance Imaging Vol.19 No.4

Purpose: For a single time-point hyperpolarized $^{13}C$ magnetic resonance spectroscopy imaging (MRSI) of animal models, scan-time window after injecting substrates is critical in terms of signal-to-noise ratio (SNR) of downstream metabolites. Pre-scans of time-resolved magnetic resonance spectroscopy (MRS) can be performed to determine the scan-time window. In this study, based on two-site exchange model, protocol-specific simulation approaches were developed for $^{13}C$ MRSI and the optimal scan-time window was determined to maximize the SNR of downstream metabolites. Materials and Methods: The arterial input function and conversion rate constant from injected substrates (pyruvate) to downstream metabolite (lactate) were precalibrated, based on pre-scans of time-resolved MRS. MRSI was simulated using two-site exchange model with considerations of scan parameters of MRSI. Optimal scan-time window for mapping lactate was chosen from simulated lactate intensity maps. The performance was validated by multiple in vivo experiments of BALB/C nude mice with MDA-MB-231 breast tumor cells. As a comparison, MRSI were performed with other scan-time windows simply chosen from the lactate signal intensities of pre-scan time-resolved MRS. Results: The optimal scan timing for our animal models was determined by simulation, and was found to be 15 s after injection of the pyruvate. Compared to the simple approach, we observed that the lactate peak signal to noise ratio (PSNR) was increased by 230%. Conclusion: Optimal scan timing to measure downstream metabolites using hyperpolarized $^{13}C$ MRSI can be determined by the proposed protocol-specific simulation approaches.

A simplified reverse beamforming algorithm based on simplex downhill optimization method for DS/CDMA Communication

Joonsung Lee,Chungyong Lee,Daehee Yoon 한국통신학회 2002 한국통신학회 학술대회논문집 Vol.2002 No.7

인터렉티브 텍스타일패턴 생성 드로잉캔버스 개발

이준승(Lee, Joonsung) 한국디지털디자인협의회 2013 디지털디자인학연구 Vol.13 No.4

텍스타일패턴디자인은 패션텍스타일제품 뿐만 아니라 모션그래픽, 인터렉티브미디어에 이르기까지 다양한 소비자의 취향과 디자인 컨셉에 맞게 활용되어지고 있다. 본 연구는 기존의 텍스타일 패턴디자인방법을 탈피하여 컴퓨터의 계산능력을 이용하여 무작위적으로 조합되는 패턴, 그 변수를 조작하여 다양한 구조를 표현할 수 있는 새로운 방향의 텍스타일패턴생성 방법을 제시한다. 이를 위해 프로세싱을 코딩하여 텍스타일패턴디자인을 생성하는 캔버스를 개발하고 공유하여 텍스타일패턴디자인 방법의 새로운 방향을 제시하는데 그 목적이 있다. 텍스타일패턴 생성 캔버스는 프린트, 애니메이션, 인터렉티브 드로잉 세 분류로 개발하였다. x, y축의 시작점, 간격, 줄개수와 모티프개체의 변수, 각 모티프들의 크기, 컬러변수를 코딩하여 실행할 때마다 매번 다르게 패턴디자인을 생성한다. 이 코딩결과물은 오픈소스이기 때문에 저작권 문제없이 누구나 웹기반의 텍스타일패턴생성 어플리케이션이나 아트프로젝트의 소스로 활용할 수 있다. 또한 사용자의 제스처 및 변수에 따라 랜덤한 텍스타일 패턴구성을 만들어 낼 수 있기 때문에 사용자경험을 유도할 수 있도록 모바일, 타블렛, 웹용 어플리케이션 등 다양한 플랫폼으로 활용이 가능하다. 후속연구에서는 본 연구에서 개발된 텍스타일패턴생성 캔버스를 웹브라우져에 프로그래밍하여 웹기반 어플리케이션으로 제작하고 이를 통해 얻게 되는 무작위 패턴결과물을 활용하여 위빙과 자카드직물을 제직하고 섬유패션제품을 개발할 것이다. Textile pattern design has been utilizing not only for fashion textile product, also realized in motion graphic, interactive media which focusing on each every purpose of design concepts based on consumer"s behavior. This research tried to avoid artificial pattern design method existing so far, it suggest randomly generated pattern design using computer"s calculational ability that could be manipulated by variation number. To make it real thing, I was coding the canvas in processing which generate textile pattern, and share it to lead a new way of textile pattern design method that is main purpose of this research. Textile pattern generate canvas has been developed as print, animation and interactive drawing. Whenever it creates different pattern design according to several variation: starting point of pattern drawing from x and y axis, its spacing, number of grid and column, list of pattern motif, number of pattern will be used, size of each pattern motif, color. This canvas code is open source so that can be applied on web based pattern generate application or a certain art project by anyone without concern about copyright. Because of it generate random textile pattern structure according to user"s gesture and variation number, it will induce a user to this experience easily. Therefore, it can be utilized with multi-platform as mobile, tablet and web based application. In next research, this canvas will be programmed and placed on responsive web based application. The visual pattern results throughout in here will be made as weave and jacquard fabrics and develop textile fashion design product with the fabrics.

프로세싱자바스크립트를 활용한 패턴디자인 생성 인터렉티브 웹어플리케이션 개발

이준승(Lee, Joonsung) 한국디지털디자인협의회 2013 디지털디자인학연구 Vol.13 No.4

패턴디자인은 최근 용도에 따라 의류, 패션액세서리, 제품패키지, 카드, 장식물, 행사사인, 애니메이션, 광고영상에 사용되는 모션그래픽에 까지 빈번하게 활용되고 있고, 인터렉티브 미디어로써도 각광을 받고 있다. 본 연구에서는 패턴디자인이 인터렉티브 멀티미디어 콘텐츠로 적극 활용될 수 있도록 하는 데에 그 목적이 있었으며, 코딩을 통한 패턴생성 알고리즘을 바탕으로 컬러, 사운드와 같이 하이퍼미디어를 선택하여 경험할 수 있는 인터렉티브 패턴생성 웹어플리케이션을 개발하였다. 어플리케이션의 콘텐츠는 크리스마스 패턴, 컬러와 사운드 세 종류의 선택데이터가 연결되도록 HTML5, CSS3, WebGL, PHP, jquery, Java Script, Processing.js를 사용하여 프로그래밍하였다. 후속 연구에서는 웹어플리케이션의 인터렉션을 통한 패턴디자인결과물을 테스트 및 DB화하여 패브릭으로 적용한 연구가 진행될 것이다. 이 연구를 통해 HTML5 환경에서 세부화된 사용자를 대상으로 하이퍼미디어 웹어플리케이션의 다양한 개발시도가 이루어 질 것으로 기대한다. Currently christmas pattern design is often utilizing for clothes, fashion accessories, product package, card, decoration, season greeting sign, contents of animation, even applying on motion graphic related in advertisement film and getting the limelight by interactive media also. The purpose of this research is verify that pattern design can be actively utilized as an Interactive multi-media contents, So I produce development of interactive application let user have experience of select color and sound as a hypermedia based on algorithm generate pattern through coding. There are three main application contents: pattern, color and sound, in which are connected by programming with HTML5, CSS3, WebGL, PHP, jquery, Java Script, Processing.js language. Next coming study will be test of pattern design results through interaction of web application and build them as database for applying fabric products. Based on this study, expecting advanced developing attempt of hyper media web application dealing with various HTML5 environment for specified user as a future comsumer.

걷기 운동 시 심박수와 가속도센서를 이용한 VO_2max 간접측정법 개발

박준성 ( Joonsung Park ),이병선 ( Byungsun Lee ),최현민 ( Hyunmin Choi ),박준성 ( Joonsung Park ),홍규석 ( Gyuseog Hong ),노호성 ( Hosung Nho ),( Joonsung Park ) 한국스포츠정책과학원(구 한국스포츠개발원) 2017 체육과학연구 Vol.28 No.1

[목적] 본 연구는 20대 남녀를 대상으로 일정속도로 걷기 시 심박수와 가속도센서를 이용하여 신뢰도와 타당도, 경제성이 높은 VO_2max 간접측정법을 개발하였다. [방법] 총 107명(남성: 55명, 여성: 52명)의 연구 대상자는 신체구성 측정 후 운동부하테스트와 두 번의 1,600 m 걷기(빠르게 걷기, 일정속도 걷기)에 참여하였다. 연구대상자의 연령과 신체적 특성, 그리고 걷기 시 측정된 시간, heart rate (HR), 또는 HR과 activity count per minute (ACM)의 비율(HR/ACM)을 변인으로 회귀분석을 시행하였다. 개발된 추정식의 타당도 검증을 위하여 직접법에 의한 VO_2max와 추정식에 의한 VO_2max의 상관관계분석과 예측잔차합제곱(predicted residual sum of squares)를 시행하였다. 또한, 직접법에 의한 VO_2max와 추정식에 의한 VO_2max의 차이를 분석하기 위하여 Bland-Altman plotting과 선형회귀분석을 실시하였다. [결과] 구간별(400 m, 800 m, 1,200 m, 1,600 m) HR/ACM과 걷기시간이 성별, 연령과 함께 직접법에 의한 VO_2max와 유의한 상관관계가 나타났다. 모든 구간에서 추정식이 개발되었으나 400m에서만 직접법에 의한 VO_2max와 차이가 없었다(R2: 0.675, %SEE: 10.7). VO_2max=121.659+6.656×Gender-0.865×Age-9.540×Time-2460.952×HR/ACM(Gender, 0=female, 1=male: Time, hundredth of a minute: HR, heart rate: ACM, activity count per minute). 모든 구간에서 빠르게 걷기보다 일정속도로 걷기 시 운동강도(%HRmax)가 낮게 나타났다. [결론] 따라서 본 연구를 통해 개발된 추정식을 통해 보다 짧은 거리 또는 보다 낮은 강도의 걷기를 통해 20대 성인의 VO_2max측정이 가능할 것으로 사료된다. [Purpose] The purpose of this study was to develop the new indirect method assessing maximal oxygen uptake (VO_2max) using heart rate (HR) and accelerometer during walk exercise. [Methods] One hundred seven participants (55 male, 52 female) performed a graded exercise test to determine VO_2max and two types of 1,600 m walk exercises (fast walk and pace controlled walk). The equations for estimating VO_2max was developed by stepwise multiple regression. The validity of developed equations tested through the correlation between measured VO_2max and estimated VO_2max, was assessed by predicted residual sum of squares, and Bland-Altman plotting. [Results] VO_2max was correlated with time, and HR/activity count per minute (ACM) measured in pace controlled walk exercise at all distance (400 m, 800 m, 1,200 m, 1,600 m). The equations were valid significantly and their multiple correlation coefficients or standard estimated error were similar to that Åstrand-Rhyming cycle ergometer test or Rockport 1 mile walk test. Using HR/ACM in pace controlled walk (400 m), it was possible to estimate VO_2max (R²: 0.675, %SEE: 10.7). The equation was: VO_2max=121.659+6.656×Gender-0.865×Age-9.540×Time-2460.952×HR/ACM (Gender, 0=female, 1=male: Time, hundredth of a minute: HR, heart rate: ACM, activity count per minute). [Conclusion] Estimation equations developed in this study are considered to estimate VO_2max through a shorter distance, or a lower intensity of walk exercise. It is required studies to target a wide range of ages or to develop walk test on a lower bpm.

스테레오스코픽 애너글리프 3D효과를 적용한 패브릭패턴디자인연구

이준승(Lee, Joonsung) 한국디자인지식학회 2013 디자인지식저널 Vol.27 No.-

최근 패브릭디자인제품은 트렌드와 컬러 그리고 소비자의 기호도까지 반영된 디자인컨텐츠의 개발아래 생산되고 있다. 이 상황에서 수익성이 높은 패브릭디자인과 소재를 개선하기 위해 대중의 관심을 받는 모든 콘텐츠에 주목할 필요가 있다. 이 연구에서는 리얼 3D라고도 불리우며 3D모션픽쳐시스템에서 분류된 스테레오스코픽 3D 효과에 주목한다. 이 기술은 컴퓨터그래픽기술의 발달로 빠르게 진화하고 있다. 기본적인 이 연구의 핵심은 3D 효과가 적용된 패브릭패턴디자인을 개발하고 제안하는 것이다. 최종목표는 애너글리프 3D 효과의 수용성을 검토하고 제한성을 분석해내는 것이다. 애너글리프 3D효과를 적용하기 위해 실험에 사용한 패턴디자인은 연구자가 개발한 디자인들이 사용되었다. 이 패턴디자인들은 고채도 톤과 보색채도의 컬러가 두드러지게 나타나기 때문에 애너글리프 3D적용이 용이하고 식별하기 편리하기 때문이었다. 그리고 이러한 특징은 애너글리프 3D 이미지의 레드와 시안컬러 필터와 상반성과 가장 부합하기도 하다. 애너글리프 3D효과를 적용한 패브릭패턴디자인의 프린팅실험은 전사 DTP로 진행하였는데, 텐션이 크고 얇은소재 이외에는 3D효과가 구현됨을 확인하였다. 후속연구로 니트나 위빙 그리고 자카드방식으로도 3D효과를 테스트한다면, 애너글리프 3D 패브릭패턴디자인은 독특한 디자인컨텐츠로써의 차별성을 가질 것으로 기대된다. 유일한 애너글리프 3D의 제한성은 그린과 핑크계열의 컬러를 인식하기 어렵다는 것이다. Current fabric design goods has been produced upon development of design contents which applying by trends, colors and consumer"s preference. This moment need to focus on every popular contents for improvement of profitable fabric design and material. In this research, attention to Stereoscopic 3D effect also called Real 3D that categorized in 3D motion picture system which has been rapidly advanced by development of computer graphic technology. Basically, main core of this study is that making and suggesting knit pattern design applied anaglyph 3D. This research"s final goal is reviewing availability of anaglyph 3D effect and analyze the limitation also. For testing anaglyph 3d effect, the pattern designs used created by researcher. These pattern designs have vivid tone and opposite chroma colors which appropriate with anaglyph 3D effect and the most compatible with red and cyan color filter of anaglyph 3D image. Fabric pattern design products applied anaglyph 3D effect tested by transfer dying digital printing method. The result is that anaglyph 3D effect was embodied on testing fabric except some fabrics which has high tension or thin ones. Anaglyph 3D has discrimination as a unique design contents. If next research approach to testing 3D effect with knit, weaving and jacquard method. Only limitation of this anaglyph 3D is hard to notice some colors like green and pinkish objects.

지역난방 수요처 제어방법 개선에 따른 효과분석 연구

이태원(Taewon Lee),황지현(Jihyun Hwang),안준성(Joonsung Ahn),이재문(Jaemoon Lee) 대한설비공학회 2017 대한설비공학회 학술발표대회논문집 Vol.2017 No.6

Recently district heating system has evolved rapidly in Korea. But because of the system built on a massive scale, the pressure variation has been very serious and the user facility"s control had accordingly made it more difficult. In this study, the field test were carried out to verify the performance of the newly proposed control method with DPV, compared to the existing control method(PDCV and TCV). As results, it was proved that the averaged temperature difference between supply and return water increased to about 15℃, which yielded over 20% saving of mass flow rate per day of district hot water compared with the conventional control method.

A Four-Camera VGA-Resolution Capsule Endoscope System With 80-Mb/s Body Channel Communication Transceiver and Sub-Centimeter Range Capsule Localization

Jang, Jaeeun,Lee, Jihee,Lee, Kyoung-Rog,Lee, Jiwon,Kim, Minseo,Lee, Yongsu,Bae, Joonsung,Yoo, Hoi-Jun IEEE 2019 IEEE journal of solid-state circuits Vol.54 No.2

<P>A small form-factor, lightweight wireless capsule endoscope (WCE) system with body channel communication (BCC) transceiver ICs is proposed for VGA-resolution image transferring and capsule localization. The transceiver ICs are composed of capsule chip and receiver chip, implemented in a 65-nm CMOS process. In the capsule side, the proposed system provides 360° image capturing through four-camera integration to reduce the miss rate. Also, a dual-band pulse-shaping BCC transmitter is proposed to enable low-power (<1 mW), high-speed (80 Mb/s) image transmission. In the receiver side, contact attenuation compensated-received signal strength indicator (CAC-RSSI) is proposed to increase the capsule localization accuracy. The external system is composed of eight-receiver nodes that allow signal demodulation and localization of the capsule. To reduce transceiver payload and system power consumption, image encoder is implemented in the capsule. The transceiver IC is integrated into the capsule system and verified with body mimicking phantom. The proposed system satisfies compatibility with medical grade diagnosis by operating longer than 8 h with 4 fps and 12 h with 2 fps with conventional two silver oxide 55-mA · h coin batteries. The tested localization accuracy shows less than sub-centimeter range.</P>