• 한국방사선학회논문지
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• 제17권7호
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• pp.1179-1187
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• 2023

최신 이동수단 발달과 관련하여 다양한 생체 신호 및 의료영상 측정용 의료기술 개발이 활발히 이루어 지고 있다. 특히, 인지/신경과학 분야에서 뇌파(electroencephalography, EEG) 측정의 중요성과 이동 중 차량에서의 정확한 뇌파 측정기술 개발은 매우 도전적인 분야이다. 본 연구에서는, 운전 중 뇌파를 이용한 기술에 대해 광범위하게 조사하고, 기술 연구의 동향을 분석하고자 하였다. 이를 위해, Scopus 데이터베이스를 활용하여 2000년 이후 진행된 뇌파 관련 연구를 탐색하였으며, 약 40여편의 논문을 선정하였다. 이를 통해 신호처리 기술, EEG 측정 디바이스 개발, 차량 내 운전자 상태 모니터링 기술의 현재 동향과 미래 방향을 조명하였다. 또한, 이를 위한 초소형 32채널 뇌파 측정 시스템을 설계해 보았으며, 간단히 이를 구현하여 뇌파 신호를 측정 분석함으로써 검토해 보았다. 본 연구는 운전 중 생체신호 측정 및 분석 기술이 자율주행 시대에 맞추어 운전자 케어와 건강 모니터링에 기여할 것으로 기대한다.

• 한국광학회지
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• 제11권6호
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• pp.452-456
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• 2000

동맥혈의 맥동성분에 의한 파장별 광흡수도를 측정하여 비침습적으로 산소포화도 값을 알수 있는 펄스옥시미터 장치와 신호처리방법을 개발하고 예측 알고리즘을 적용하였다. 본 장치는 광원 및 검출기로 구성된 프로브와 광신호 처리부, LED 구동회로 PC 인터페이스부로 구성되었고 데이터의 수집을 위한 구동소프트웨어 및 데이터 처리 소프트웨어를 개발하였다. 개발된 산소포화도 측정장치의 성능을 평가하는데에는 Bio-Tek 사의 펄스 옥시미터 시뮬레이터를 사용하여 다양한 알고리즘 및 데이터처리 방법들을 비교분석한 결과 맥동파형의 $In(I_p/I_v) 값을 I_{avr}$값으로 보정하는 계산 알고리즘의 방법과 진폭비보다 면적비를 이용한 계산방법이 산소포화도와의 상관관계가 우수한 것으로 나타났다. 정확한 신호 획득을 위해 개발된 맥동의 기저선 보상처리 프로그램을 inv-vivo 테스트의 데이터 처리방법에 적용하여 결과가 향상되는 것을 확인하였고 광원으로 660nm(Red)와 805nm(IR)파장을 이용한 경우보다 660nm(Red)와 940nm(IR) 파장을 이용했을 때 산소포화도와의 상관관계 및 정밀도에서 더 우수한 결과를 얻을 수 있었다.

• Transactions on Electrical and Electronic Materials
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• 제12권6호
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• pp.253-257
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• 2011

This study was carried out to solve problems such as radio frequency band depletion, confusion risk, and security loss in existing visible wireless communication systems, and to determine the applicability of next-generation networks. A light-emitting diode (LED) light communication system was implemented with a controlling switching light module using the ATmega16 micro-controller. To solve the existing modulation effect and disturbance in visible light communication, an integrated interface was evaluated with a driving light module and analyzes its reception property. A transmitter/receiver using the ATmel's micro-controller, high-intensity white LED-6 modules, and infrared sensor KSM60WLM and visible sensor TSL250RD were designed. An experiment from the initial value of distance to 2.5 m showed 0.46 V of the voltage loss, and if in long distance, external light interference occurred and light intensity was lost by external impact and thus data had to be modified or reset repeatedly. Additionally, when we used 6 modules through the remote controller's lighting dimming, data could be transmitted up to 1.76 m without any errors during the day and up to 2.29 m at night with around 2~3% communication error. If a special optical filter can reduce as much external light as possible in the integrated interface, the LED for lighting communication systems may be applied in next generation networks.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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• pp.2835-2838
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• 2003

We study the characteristics of oscillating in non-autonomous condition and the conducted noise generation in a RL-photocoupler circuit. This circuit may be shown a period-doubling and a chaos dynamics under any specific conditions of input circuit. But, the relationship between input signals and output signals is different according to the amplitude of driving input voltage. Then, the oscillation noise was analyzed with respect to both the frequency and the amplitude of an external ac signal and do values. The results show that the noise-induced oscillations for falling and rising cycles induced by kick-back effect in an inductor, nonlinear capacitance, nonlinear resistance and charge storage time in a diode and an LED. We also compared the simulation with the experimental results.

• 반도체디스플레이기술학회지
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• 제6권4호
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• pp.43-47
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• 2007

In this paper, we propose a novel sensor system for measuring the arterial pulse in an oral cavity. In order to measure pulse wave in oral cavity, the proposed system is designed with reflection type arterial wave sensor, not by using transmission type arterial pulse wave sensor. Driving circuit through pulse current is designed for solving self-heating problem of LED. The effectiveness of the proposed sensor system is compared with pulse wave between pulse wave of oral cavity and other body parts as well as with characteristic measurements. The experiment shows that the proposed sensor system is adaptive to capturing consecutive and meaningful biometric signals through the variation of pulse wave changes in oral cavity when exercising. The study result expects to design and develop mobile sensors which could be adapted to healthcare devices.

• International Journal of Concrete Structures and Materials
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• 제6권3호
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• pp.199-207
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• 2012

Concrete is an economical construction material and for that reason it is widely used in buildings and infrastructures. The use of deicing salts, expansion joint failure, and freeze-thaw cycles have led to concrete bridge girders experiencing corrosion of steel reinforcement and becoming unsafe for driving. The goal of this research is to assess the effectiveness of current and possible repair techniques for the end region of damaged prestressed concrete girders. To do this, three American Association of State Highway and Transportation prestressed concrete girders were tested to failure, repaired, and retested. Three different repair materials were tested including carbon fiber, glass fiber, and surface mounted rods. Each different repair material was also tested with and without injected epoxy. Comparisons were then made to determine if injecting epoxy had a positive effect on stiffness and strength recovery as well as which repair type regained the largest percentage of original strength.

• 통상정보연구
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• 제9권4호
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• pp.91-104
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• 2007

The recent stabilization of the Internet is now driving every aspect of life into an Internet presence. In the coming years, the Internet will see growth in numbers unlike the world has ever seen. The subject of this study is the Research Study on the Products Purchase Type of On-line Shopping Mall Buyer. Also, this paper is to examine the relations between customer satisfaction and intensity of repurchase intention and complaining behavior in on-line context. On-line shopping customer depths interview it led and the online afternotes trust evaluation dimension was discovered the of useful characteristic, intention characteristic, exaggerating characteristic and on-line afternotes with or without. From these results, this paper suggests effective marketing strategy to the marketer who plans to run on-line shopping mall in the near future and also to the marketer who plans to sell products through the on-line shopping mall.

• 전기전자학회논문지
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• 제22권3호
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• pp.585-589
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• 2018

Consumer demand for high quality image/video services led to growing trend in image quality enhancement study. Therefore, recent years was a period of substantial progress in this research field. Through careful observation of the image quality after processing by image enhancement algorithms, we perceived that the dark region in the image usually suffered loss of contrast to a certain extent. In this paper, the low-light stretch preprocessing algorithm is, hence, proposed to resolve the aforementioned issue. The proposed approach is evaluated qualitatively and quantitatively against the well-known histogram equalization and Photoshop curve adjustment. The evaluation results validate the efficiency and superiority of the low-light stretch over the benchmarking methods. In addition, we also propose the 255MHz-capable hardware implementation to ease the process of incorporating low-light stretch into real-time imaging systems, such as aerial surveillance and monitoring with drones and driving aiding systems.

• Ocean and Polar Research
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• 제25권4호
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• pp.617-623
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• 2003

Organisms living in the Arctic and Antarctic regions are exposed to strong constraints, of which temperature is a driving factor. Evolution has led to special adaptations, some with important implications at the biochemical, physiological, and molecular levels. The northern and southern polar oceans have very different characteristics. Tectonic and oceanographic events have played a key role in delimiting the two polar ecosystems and influencing evolution. Antarctica has been isolated and cold longer than the Arctic; its ice sheet developed at least 10 million years earlier. As an intermediate system, the Arctic is a connection between the more extreme, simpler Antarctic system and the very complex temperate and tropical systems. By studying the molecular bases of cold adaptation in polar fish, and taking advantage of the information available on hemoglobin structure and function, we analysed the evolutionary history of the ${\alpha}\;and\;{\beta}globins$ of Antarctic and Arctic hemoglobin using the molecular clock hypothesis as a basis for reconstructing the phylogenetic relationships among species.

• Journal of Advanced Marine Engineering and Technology
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• 제33권5호
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• pp.662-671
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• 2009

In this paper, a robot was developed for in-pipe cleaning and inspecting a large number of circular in-pipes of sea plants, ships, and buildings. A pressure generation mechanism was devised to inspect circular in-pipes with different diameters and to move up and down slant or perpendicular slopes in-pipes. For inspection of the dark inner side of the pipe, a light system using LED which dissipats small electricity was developed. Also, a design method was analyzed to decide the capacity of driving motor for the robot when the mass and maximum velocity of the robot are identified. The robot developed based on the design specification, was tested to verify the performance of the pressure generation mechanism. In addition, a control system was developed for the test.