• Fire Science and Engineering
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• v.28 no.6
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• pp.62-68
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• 2014

The high predictive performance of fire detector models is essentially required for the reliable design of evacuation safety using the fire modeling. The main objective of the present study is to measure input information in order to predict the accurate activation time of photoelectric smoke detector adopted in fire dynamics simulator (FDS) recognized a representative fire model. To end this, the fire detector evaluator (FDE) which could be measured the device properties of detector was used, and the input information of Heskestad and Cleary's models was obtained for a spot-type photoelectric smoke detector. In addition, the activation times of smoke detector predicted using default values into FDS and measured values in the present study were quantitatively compared. As a result, the Heskestad model could result in an inaccurate the activation time of photoelectric smoke detector compared to the Cleary model. In addition, there was a distinct difference between the default values used into FDS and the measured values in terms of device properties of smoke detector, and thus the activation time also showed a significant difference.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.4
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• pp.273-287
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• 2001

In this paper, we introduce our experience for designing and implementing a media manager in the Integrated Streaming Service Architecture (ISSA) developed by the authors. The media manager is regarded as a necessary module in the ISSA framework for the following reasons. It realizes that from which locations of the media source devices, the media streams are coming. Once it knows where the origin is, the media manager should recognizes what types of stream are. After that, it performs how to chose an appropriate CODEC to handle the recognized input streams efficiently, and what type of media playback device should be selected. In order to do such a job efficiently, the proposed media manager consists of two modules source module and sink module. The major role of a media source module is to make an abstraction for the media streams that are coming from various types of media device. This, in consequence, enables a media manager to consistently handle tlle media streams without considering wherever they come from. On the other hand, the media sink module distributes the input streams to an appropriate media device to playback. One of the remarkable virtues of the proposed media manager is an ability to supporting high value-added database services since it provides an interface between the ISSA and real-time multimedia database. Also, it provides the RTP!RTSP source filter and Winamp gateway modules which allow the flexibility to the system. Moreover, the media manager can adopt any types of new media which in fact will provide scalability to the ISSA.

• Journal of Technology Innovation
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• v.12 no.1
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• pp.25-48
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• 2004

The relative efficiency of loan projects of information technology promotion fund is measured using Data Envelopment Analysis. Information technology promotion project is supervised by the Ministry of Information and Communication and is managed by the Institute of Information Technology Assessment. Among all the projects of information technology supported by this fund, this study deals with the themes that have been completed from 2000 to 2002. With multiple input and output data including the amount of fund, the period of study, the rate of increase in revenue, the increase in the amount of export and the increase in the number of patent, the relative efficiency scores of all the 119 subjects were calculated in CCR and BCC models of DEA. From the reference sets of some inefficient Decision Making Units, the causes of their inefficiency were analyzed. To compare the relative efficiencies among various DMUs, Super-Efficiency Ranking Method and Logistic Regression Model were used. As the result of this study, it was shown that W promotion funds in the fields related to mobile technology, visual equipment and communication device were used most efficiently.

• Journal of Biomedical Engineering Research
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• v.40 no.5
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• pp.179-188
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• 2019

In ultrasound telemedicine, it is important to reduce the size of the data by compressing the ultrasound image when sending it. Ultrasound images can be divided into image context and other information consisting of patient ID, date, and several letters. Between them, ultrasound context is very important information for diagnosis and should be securely preserved as much as possible. In several previous papers, ultrasound compression methods were proposed to compress ultrasound context and other information into different compression parameters. This ultrasound compression method minimized the loss of ultrasound context while greatly compressing other information. This paper proposed the method of automatic segmentation of ultrasound context to overcome the limitation of the previously described ultrasound compression method. This algorithm was designed to robust for various ultrasound device and to enable real-time operation to maintain the benefits of ultrasound imaging machine. The operation time of extracting ultrasound context through the proposed segmentation method was measured, and it took 311.11 ms. In order to optimize the algorithm, the ultrasound context was segmented with down sampled input image. When the resolution of the input image was reduced by half, the computational time was 126.84 ms. When the resolution was reduced by one-third, it took 45.83 ms to segment the ultrasound context. As a result, we verified through experiments that the proposed method works in real time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.3
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• pp.371-377
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• 2020

Currently used iris cameras are expensive and have many limitations in their use. Existing iris cameras are inconvenient in interworking with newly developed software, and light reflections generated during iris photography are inadequate for medical use. Therefore, it is impossible to utilize the existing camera to take an image by yourself. In this paper, the iris camera is newly constructed so that the iris can be photographed by ourselves and the area of interest can be seen well. Anyone can easily wear glasses-type iris cameras to acquire images using IoT devices, and the acquired images are linked to the iris analysis program and used to read genetic weak parts. The proposed iris camera module automatically provides light reflection, shake, and accurate focus when capturing images, increasing the accuracy of image analysis to 91.49%. In addition, we have proved through experiments that one image processing time is fast as 0.007ms due to accurate image input.

• Journal of Power System Engineering
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• v.13 no.2
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• pp.71-82
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• 2009

This paper presents a real-time haptic rendering method for a realistic force feedback in a remote environment with varying communication time-delay. The remote environment is assumed as a virtual environment based on a computer graphics, for example, on-line shopping mall, internet game and cyber-education. The properties of a virtual object such as stiffness and viscosity are assumed to be unknown because they are changed according to the contact position and/or a penetrated depth into the object. The DARMAX model based output estimator is proposed to trace the correct impedance of the virtual object in real-time. The output estimator is developed on the input-output relationship. It can trace the varying impedance in real-time by virtue of P-matrix resetting algorithm. And the estimator can trace the correct impedance by using a white noise that prevents the biased input-output information. Realistic output forces are generated in real-time, by using the inputs and the estimated impedance, even though the communication time delay and the impedance of the virtual object are unknown and changed. The generated forces trace the analytical forces computed from the virtual model of the remote environment. Performance is demonstrated by experiments with a 1-dof haptic device and a spring-damper-based virtual model.

• Journal of the Korean Institute of Telematics and Electronics
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• v.11 no.6
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• pp.38-43
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• 1974

A design problem is studied for a nonuniform transmission line (NUTL) section to be inserted between an arbitrary source impedance and an arbitary load impedance for the purpose of impedance matching or providing a minimum input reflection coefficient over a frequency ranee as wide as possible. A special class of NUTL's, yet comprehensive enough to include almost all smoothly varying lines, are considered. Power series expansions of the ABCD parameters of such lines are used in the calculation of the input reflection coefficient. The design problem is formulated as a nonlinear programming problem withnonlinear constraints and is solved by a combined use of the sequential unconstrained minimization technique and tile Fletcher-Powell method. As a result, a line section was obtained which shows a marked improvement over any one hitherto published as a wide-band impedance matching device.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.1-6
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• 2008

This paper proposes a game controller that provides user motion input and tactile feedback display, in addition to the traditional button-type input. The device utilizes both an accelerometer and an infrared camera in order to estimate 3D position and to recognize user motion. The information from the accelerometer and the camera are integrated for better performance. Various tactile sensations are presented using a voice-coil type vibrator. We apply the proposed controller to a motion-based game and validate its usability.

• Journal of Digital Convergence
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• v.13 no.6
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• pp.177-184
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• 2015

Brain-computer interface is (BCI) is a communication device that the brain activity is directly input to the computer without input devices, such as a mouse or keyboard. As the brain wave interface hardware technology evolves, expensive and large EEG equipment has been downsized cheaply. So it will be applied to various multimedia applications. Among BCI studies, we suggest the domestic and foreign research trend about how the BCI is applied about the game almost people use. Next, look at the problems of the game with the BCI, we would like to propose the future direction of domestic BMI research and development.

• 전자공학회논문지 IE
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• v.47 no.3
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• pp.47-52
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• 2010

In this paper, a frequency tripler has been designed with 100mW medium-power using P-HEMT. It is designed to obtain 7.2GHz frequency at the output that is an integer multiple of 2.4GHz input frequency by using nonlinear device that produces 3rd harmonic. The frequency tripler is designed by using load-pull simulation. To suppress the 2nd and fundamental, notch filter is used for the frequency tripler. The tripler is designed to obtain about 21dBm output power with 15dBm input, i.e., 6dB conversion gain and the suppression of 20dBc at fundamental, and 30dBc at the second harmonics.