• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권12호
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• pp.4451-4466
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• 2014

We present joint radio selection and relay scheme that delivers data from a source to a sink in heterogeneous stationary sensor networks consisting of various radio interfaces. The proposed scheme finds the optimal relay nodes and their corresponding radio interfaces that minimize energy consumption throughout the network while satisfying the end-to-end packet deadline requirement. We formulate the problem of routing through radio interface selection into binary integer programs, and obtain the optimal solution by solving with an optimization solver. We examine a trade-off relationship between energy consumption and packet delay based on network level simulations. We show that given the end-to-end deadline requirement, our routing algorithm finds the most energy-efficient routing path and radio interface across mesh hops. We demonstrate that the proposed routing scheme exploits the given packet delivery time to turn into network benefit of reducing energy consumption compared to routing based on single radio interface.

• 센서학회지
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• 제13권3호
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• pp.236-243
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• 2004

In this paper, we proposed a brain-computer interface system using EEG signals. It can generate 4 direction command signal from EEG signals captured during imagination of subjects. Bandpass filter used for preprocessing to detect the brain signal, and the power spectrum at a specific frequency domain of the EEG signals for concentration status and non-concentration one is used for feature. In order to generate an adequate signal for controlling the 4 direction movement, we propose a new interface system implemented by using a support vector machine and a time-multiplexing method. Moreover, bio-feed back process and on-line adaptive pattern recognition mechanism are also considered in the proposed system. Computer experimental results show that the proposed method is effective to recognize the non-stational brain wave signal.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권2호
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• pp.155-167
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• 2015

An adaptive equalization scheme based on all-digital jitter measurement is proposed for a continuous time linear equalizer (CTLE) preceding a clock and data recovery (CDR) in a receiver circuit for high-speed serial interface. The optimum equalization coefficient of CTLE is determined during the initial training period based on the measured jitter. The proposed circuit finds automatically the optimum equalization coefficient for CTLE with 20", 30", 40" FR4 channel at the data rate of 5 Gbps. The chip area of the equalizer including the adaptive controller is 0.14 mm2 in a $0.13{\mu}m$ process. The equalizer consumes 12 mW at 1.2 V supply during the normal operation. The adaptive equalizer has been applied to a USB3.0 receiver.

• 정보처리학회논문지D
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• 제15D권5호
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• pp.691-698
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• 2008

웹사이트의 구조를 표현하고 설계하는 일반적인 방법으로 스토리보드나 사이트 맵 또는 플로우 차트 등을 사용하거나 또는 이들을 조합하여 사용하는 방법이 있다. 그러나 이들은 웹사이트의 전체 구조를 표현하기 어렵고 웹페이지 간의 세부적인 흐름 관계를 표현하기에 부적절한 면이 있다. 이러한 문제점을 다소 해결하기 위하여 EMFG(Extended Mark Flow Graph)를 이용하여 웹사이트를 표현하고 설계하려는 연구가 진행되었다. 그런데 이러한 기존의 연구는 웹사이트의 정적인 부분들을 대부분 표현하였기 때문에 동적인 웹사이트의 인터페이스를 표현하고 설계하기에는 부족한 점이 있다. 그리고 현재 인터넷의 생활화가 가속화되어 감에 따라 웹사이트의 구조가 더욱 다양하고 복잡하게 되었을 뿐 아니라 인터페이스도 많은 부분에서 동적인 부분을 포함하게 되었다. 따라서 본 연구에서는 EMFG를 사용하여 복잡하고 다양한 웹사이트의 구조뿐만 아니라 동적인 인터페이스 - 예를 들어, 시간에 따라 변하는 페이지 구조 또는 마우스 동작에 따라 변하는 페이지 상태나 구조 등 - 를 표현하는 방법을 제시한다. 본 연구가 웹사이트를 설계하는데 많은 도움이 되고, 웹사이트의 유지보수에도 도움이 될 수 있을 것으로 기대한다.

• Journal of Welding and Joining
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• 제33권2호
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• pp.47-55
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• 2015

With using adaptive control of the resistance spot welding machine, the advantage on electrode life time for galvanized steels has been addressed. This study was aimed to evaluate the electrode life time of galvanized steels with applying the constant current control and the adaptive control resistance spot welding process for a comparison purpose. The growth in diameter of electrode face was similar for both the constant current and the adaptive control up to 2000 welds. The button diameter was decreased with weld numbers, however, sudden increase in button diameter with use of the adaptive control after 1500 welds was observed. The peak load was continuously decreased with increasing number of welds for both the constant current and the adaptive control. The current compensation during a weld was observed with using the adaptive control after 1800 welds since the ${\beta}$-peak on dynamic resistance curve was detected at later weld time. The current compensation with adaptive control during resistance spot welding enhanced the nugget diameter at the faying interface of steel sheets and improved the penetration to thinner steel sheet.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.717-722
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• 2003

A driving simulator is a computer-controlled tool to study an interface between a driver and vehicle response by enabling the driver to participate in judging vehicle characteristics. Using the driving simulator, human factor study, vehicle system development and other research can be effectively done under controllable, reproducible and non-dangerous conditions. An Adaptive Cruise Control (ACC) system is generally regarded as a system that can be achieved in the near future without the demanding infrastructure components and technologies. ACC system is an automatic vehicle following system with no human engagement in the longitudinal vehicle direction. And the influence of the driver is substantial in developing the system. Driving characteristic is very different according to the accident riskiness, gender, age and so on. In this research, experiments have been carried out to investigate driving characteristics with the ACC system, using a driving simulator. Participants are 21 male and 19 female. Driving characteristics such as preferred headway-time, lane keeping ability, eye direction, and head movement have been observed and compared between the driving with ACC and the driving without ACC.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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• pp.109-110
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• 2006

The performance of a digital baseband signal processing and data transmission rate depends on the modulation technique. In this paper, We implemented DSP communication system for Underwater acoustic communication using by adaptive BPSK modem technique. In order to implement adaptive modem, we suggested SNR detection block. SNR detection block has the reference SNR value that selects between window filter path and matched filter path. In this paper, suggested system is based on software interface and all Hardware(PLL, modem filter, equalizer etc) is implemented by software, exclusive of DSP, A/D, D/A converter, SDRAM and Flash memory.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.690-694
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• 1996

In order to regulate the cutting force at a desired level during peripheral end milling processes, a feedrate override Adaptive Control Constant system was developed. This paper presents an explicit pole-assignment PI-control law through spindle motor current monitoring and its application to cutting force regulation for feedrate optimization. An experimental set-up is constructed for the commercial CNC machining center without any major changes of the structure. A data transfer system is constructed with standard interface between an IBM compatible PC and a CNC of the machining center. Experimental results show the validity of the system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.537-539
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• 1998

In this paper, we construct the on-line model structure for the nonlinear process systems using the adaptive fuzzy-neural network. Adaptive fuzzy-neural network usually consists of two distinct modifiable structure, with both, the premise and the consequent part. These two parts can be adapted by different optimization methods, which are the hybrid learning procedure combining gradient descent method and least square method. To achieve the on-line model structure, we use the recursive least square method for the consequent parameter identification of nonlinear process. We design the interface between PLC and main computer, and construct the monitoring and control simulator for the nonlinear process. The proposed on-line modeling to real process is carried out to obtain the effective and accurate results.

• Structural Engineering and Mechanics
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• 제45권6호
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• pp.779-802
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• 2013

In this paper, adaptive neuro-fuzzy inference system (ANFIS) and artificial neural networks (ANNs) techniques are developed and applied to identify damage in a model steel girder bridge using dynamic parameters. The required data in the form of natural frequencies are obtained from experimental modal analysis. A comparative study is made using the ANNs and ANFIS techniques and results showed that both ANFIS and ANN present good predictions. However the proposed ANFIS architecture using hybrid learning algorithm was found to perform better than the multilayer feedforward ANN which learns using the backpropagation algorithm. This paper also highlights the concept of ANNs and ANFIS followed by the detail presentation of the experimental modal analysis for natural frequencies extraction.