• 한국컴퓨터정보학회논문지
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• 제19권10호
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• pp.1-12
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• 2014

본 논문에서는 단일 명령어, 다중 데이터 처리 기반의 매니코어 프로세서를 이용하여 높은 계산량이 요구되는 차감 클러스터링 알고리즘을 병렬 구현하고 성능을 향상시킨다. 또한 차감 클러스터링 알고리즘을 위한 최적의 매니코어 프로서서 구조를 선택하기 위해 다섯 가지의 프로세싱 엘리먼트 (processing element, PE) 구조 (PEs=16, 64, 256, 1,024, 4,096)를 모델링하고, 각 PE구조에 대해 실행시간 및 에너지 효율을 측정한다. 두 가지 의료 영상 및 각 영상의 세 가지 해상도(($128{\times}128$, $256{\times}256$, $512{\times}512$)를 이용하여 모의 실험한 결과, 모든 경우에 대해 PEs=4,096구조에서 최고의 성능 및 에너지 효율을 보였다.

• 한국정보전자통신기술학회논문지
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• 제10권1호
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• pp.46-56
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• 2017

최근 IoT 기술의 확산이 본격화 되면서, 홈/가전/의료등 전 산업 분야에 적용되고 있는데, IoT의 저 사양, 저 전력 소모 특성과 통신 데이터 특성으로 인하여, 기존 암호화 알고리즘의 적용이 용이하지 않으며, 따라서 보안 위협에 대한 우려가 커지고 있다. 이에 대응하여 본 연구에서는, 기존의 고정비트에 대한 XOR연산을 이용한 스트림 암호화 방식에 비하여, 해당 기준 비트에서 상위 방향의 비트 패턴에 따라 불규칙적으로 결정되는 특정한 바이너리 클러스터를 기준으로 암호 키 값에 따라 자리내림, 자리올림 방식을 이용하여, 비트 값에 변화를 주는 일종의 가변 길이 비트 XOR연산 방식을 도입하여 암호화 및 복호화가 진행될 수 있음을 처음으로 제시하였다. 제안 알고리즘의 특징상 암호화 전후의 데이터 크기 변화가 없고, IoT 디바이스/QR코드/RFID/NFC가 빈번히 처리하는 짧은 메시지 데이터에 대해서도 암호화하는 실용성을 확인하였다.

• 대한의용생체공학회:의공학회지
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• 제28권6호
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• pp.768-776
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• 2007

A new type of the fluid circulation blood pressure simulator was proposed to enhance the blood pressure simulator used for the development and evaluation of automatic sphygmomanometers. Various pressure waveform of fluid flowing in the pipe was reproduced by operating the proportional control valve after applying a pressure on the fluid in pressurized oil tank. After that, appropriate fluid was supplied by operating the proportional control valve, which enabled to reproduce various pressure wave of the fluid flowing in the tube. To accomplish this work, the mathematical model was carefully reviewed in cooperating with the proposed simulator. After modeling the driving signal as input signal and the pressure in internal tube as output signal, the simulation on system parameters such as internal volume, cross-section of orifice and supply pressure, which are sensitive to dynamic characteristic of system, was accomplished. System parameters affecting the dynamic characteristic were analyzed in the frequency bandwidth and also reflected to the design of the plant. The performance evaluator of fluid dynamic characteristic using proportional control signal was fabricated on the basis of obtained simulation result. An experimental apparatus was set-up and measurements on the dynamic characteristic, nonlinearity, and rising and falling response was carried out to verify the characteristic of the fluid dynamic model. Controller was designed and thereafter, simulation was performed to control the output signal with respect to the reference input in the fluid dynamic model using the proposed proportional control valve. Hybrid controller combined with an proportional controller and feed-forward controller was fabricated after applying a disturbance observer to the control plant. Comparison of the simulations between the conventional proportional controller and the proposed hybrid simulator indicated that even though the former showed good control performance.

• 센서학회지
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• 제15권3호
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• pp.179-185
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• 2006

We have developed a noncontact temperature sensor using a silver halides infrared optical fiber. An infrared radiation from a heat source is transferred by a silver halides infrared optical fiber and measured by infrared sensors such as a thermopile and a thermal optical power-meter. The relationships between the temperature of a heat source and the output voltage of the thermopile and the optical power of a thermal optical power-meter are determined. The measurable temperature range using a thermopile and a thermal optical power-meter are from 100 to $750^{\circ}C$ and from 30 to $750^{\circ}C$ respectively. It is expected that a noncontact temperature sensor using infrared optical fiber can be developed for medical and industrial usages based on the results of this study.

• 대한디지털의료영상학회논문지
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• 제14권1호
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• pp.7-12
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• 2012

The purpose of this study was to examine usefulness of 3T equipment-based time-of-flight magnetic resonance angiography (3T-TOF MRA) by comparing standard technique (ST) with high resolution technique (HRT) in evaluation of cerebral blood vessel. The 3T-TOF MRA was performed for 31 patients who were suspected of having cerebrovascular disease from March to July 2010. For evaluation of cerebral blood vessel, classification was conducted randomly: group I that included vertebral artery and basilar artery, group II that ranged from 2.5cm before basin part of common carotid artery to basin part of internal and external carotid arteries and to genu part of internal carotid artery, group III that ranged from vertebral part of internal carotid artery to the first basin art of anterior and middle cerebral through education recognizes the importance of dose reduction and examine if their efforts and further reduce patient dose could achieve optimization of the medical exposure is considered.

• 한국정보통신학회논문지
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• 제19권4호
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• pp.948-953
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• 2015

최근, 생체 정보를 이용하여 개인의 신원을 확인하기 위해 근적외선 LED와 CCD 카메라를 이용한 지정맥 인식기술 연구되고 있다. 지정맥 인식은 손가락의 두께, 주변 광, 체온카메라 등의 잡음으로부터 정맥과 배경 이미지를 분리하는 방법에 따라 성능의 차이가 발생한다. 이러한 문제점을 개선하기 위해 본 연구에서는 NIR LED와 CCD 카메라로 촬영된 지정맥 영상으로부터 지정맥 회전, ROI 검출, 필터뱅크를 이용한 정맥 증강 기법을 제안하고 실험을 통하여 그 성능을 평가하였다. 이 실험의 결과에서 제안된 지정맥 회전과 ROI 검출의 정확도가 99.8%를 보였다. 그리고 필터뱅크를 이용한 정맥 증강처리에서는 제안된 방법이Retinex 알고리즘 보다 우수한 대비 성능을 보였다. 이 실험의 결과로부터 제안된 방법을 정맥인식의 전처리 과정에 적용한다면, 보다 나은 인식률을 제공할 것으로 사료된다.

• 대한의용생체공학회:의공학회지
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• 제38권4호
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• pp.163-167
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• 2017

The purpose of this study is to perform integrated body temperature cooling of the arteriovenous anastomosis site. In the arteriovenous anastomosis site, heart cooling was performed using the palm of the hand, Cooling was achieved by using Peltier and copper plates to cool the palm of the hand with the heat transferred. The control range of the conducted heat is adjustable from 25 degrees to 30 degrees. The experimental environment was to place the treadmill in the house, The temperature in the house was set at 40 degrees and the experimenter treadmill at a speed of 5 Km. The subjects were exercised until the body temperature reached about $39^{\circ}C$. As a method to lower the body temperature after the experiment, the data of the body temperature was obtained by the general rest, onehand cooling, two-hand cooling. Experiment result better than normal rest when Two hands cooling and an average decrease of 0.66 degrees. if you develop a cooling glove with Peltier, it will be an epoch-making athletic assistant to achieve thermal fatigue.

• Structural Engineering and Mechanics
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• 제63권4호
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• pp.429-438
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• 2017

Structural design has an imperative role in deciding the failure possibility of a Reinforced Concrete (RC) structure. Recent research works achieved the goal of predicting the structural failure of the RC structure with the assistance of machine learning techniques. Previously, the Artificial Neural Network (ANN) has been trained supported by Particle Swarm Optimization (PSO) to classify RC structures with reasonable accuracy. Though, keeping in mind the sensitivity in predicting the structural failure, more accurate models are still absent in the context of Machine Learning. Since the efficiency of multi-objective optimization over single objective optimization techniques is well established. Thus, the motivation of the current work is to employ a Multi-objective Genetic Algorithm (MOGA) to train the Neural Network (NN) based model. In the present work, the NN has been trained with MOGA to minimize the Root Mean Squared Error (RMSE) and Maximum Error (ME) toward optimizing the weight vector of the NN. The model has been tested by using a dataset consisting of 150 RC structure buildings. The proposed NN-MOGA based model has been compared with Multi-layer perceptron-feed-forward network (MLP-FFN) and NN-PSO based models in terms of several performance metrics. Experimental results suggested that the NN-MOGA has outperformed other existing well known classifiers with a reasonable improvement over them. Meanwhile, the proposed NN-MOGA achieved the superior accuracy of 93.33% and F-measure of 94.44%, which is superior to the other classifiers in the present study.

• Environmental Analysis Health and Toxicology
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• 제30권
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• pp.15.1-15.11
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• 2015

Objectives There has been a growing concern about the possible carcinogenic effects of the electromagnetic radiofrequency fields emitted from mobile phones. The purpose of this study was to investigate the association between mobile phone use and the development of gliomas in Korea. Methods Our study methods were based on the International Interphone study that aimed to evaluate possible adverse effects of mobile phone use. This study included 285 histologically-confirmed Korean patients 15 to 69 years of age, with gliomas diagnosed between 2002 and 2007 in 9 hospitals. The 285 individually matched controls were healthy individuals that had their medical check-up in the same hospitals. Unconditional logistic regression was used to calculate the adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for use of mobile phones. Results For the entire group, no significant relationship was investigated between gliomas and regular use of mobile phones, types of mobile phones, lifetime years of use, monthly service fee, and the other exposure indices. Analyses restricted to self-respondents showed similar results. For ipsilateral users, whose the body side for usual mobile phone use match the location of glioma, the aORs (95% CIs) for lifetime years of use and cumulative hours of use were 1.25 (0.55 to 2.88) and 1.77 (0.32 to 1.84), respectively. However, the contralateral users showed slightly lower risk than ipsilateral users. Conclusions Our results do not support the hypothesis that the use of mobile phones increases the risk of glioma; however, we found a non-significant increase in risk among ipsilateral users. These findings suggest further evaluation for glioma risk among longterm mobile phone users.

• 분석과학
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• 제7권3호
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• pp.301-313
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• 1994

X-선 광전자분광법(XPS)과 라더포드 후방산란법(RBS)은 첨가제 분석, 화학구조 규명은 물론 시료 표면 원소의 정성 및 정량, 결합에너지 준위, 수직분포 분석을 통한 동일성 판정 등에 응용할 수 있다. $XeF_2$와 C-F plasma로 표면을 처리한 polyethylene, acrylonitrile butadien rubber, polypropylene, glass, fiber 및 paper를 XPS와 RBS로 분석한 결과 불소원자가 시료의 표면에 침투한 것을 확인할 수 있었으며, 표면 원소의 분포가 미처리된 시료의 표면원소 분포와 차이가 있었다.