• Journal of the Institute of Convergence Signal Processing
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• v.12 no.1
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• pp.44-49
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• 2011

The need of data transmission in oceans and other underwater mediums are increasing day by day, so as the research. The underwater medium is very different from that of air. Propagation of electromagnetic wave in water or underground is very difficult because of the conductivity of the propagation materials. In this case, we usually use acoustic signals as ultrasonic but, they are not easy to transfer long distance with coherent method because of time varying multipaths, Doppler effects and attenuations. So, we use non-coherent methods such as FSK or ASK to communicate between long distances. But, as the propagation speed of acoustic wave is very slow, BW of the channel is narrow. It is very hard to guaranty the enough speed for the transmission of digital image data. In previous studies, we proposed this data communication protocol theoretically. In this paper, an underwater channel is modeled and this protocol is tested in this channel condition. The results show that the protocol is 4-6 times faster than ASK. Some relations and results are shown depending on the data length, channel length, bit rate etc.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.213-216
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• 2000

본 논문에서는 volume rendering 기법을 이용하여 2차원 MRI 영상들을 합성하여 3차원 영상 만들 때 보다 해상도를 높이기 위한 개선된 sampling방법을 소개한다 2차원 슬라이스 영상들이 3차원으로 재구성할 때 voxel 기반으로 렌더링을 하기 때문에 오브젝트의 내부 영역까지도 볼 수 있는 것이 volume rendering의 가장 큰 장점이다. 따라서 영상을 재구성하는 과정에서 보다 향상된 interpolation을 적용시켜서 공간 해상도를 향상시키면 보다 명확하게 오브젝트 내부 정보를 살펴 볼 수 있다. 본 논문에서는 nearest neighbor 이나 linear 같은 interpolation으로 sampling한 방법보다 cubic interpolation을 3차원 공간에서 적용 시켜서 보다 resampling이 잘 되도록 하여 해상도를 향상시켜 보았다. 이렇게 향상된 Interpolation 적용시켜서 렌더링할 때 얼마나 오브젝트 내부 영역이 잘 가시화가 되었는지 transfer function을 적용시켜서 오브젝트 내부 정보를 렌더링 해보았고, 임의의 축으로 오브젝트을 잘라서 2D 단면 영상으로 출력해 보았다. 보다 향상된 interpolation을 적용시켜서 resampling을 하면 영상 해상도가 개선되었음을 볼 수 있었다.

• International Journal of Computer Science & Network Security
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• v.23 no.9
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• pp.186-191
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• 2023

Neural Networks are widely used for huge variety of tasks solution. Machine Learning methods are used also for signal and time series analysis, including electrocardiograms. Contemporary wearable devices, both medical and non-medical type like smart watch, allow to gather the data in real time uninterruptedly. This allows us to transfer these data for analysis or make an analysis on the device, and thus provide preliminary diagnosis, or at least fix some serious deviations. Different methods are being used for this kind of analysis, ranging from medical-oriented using distinctive features of the signal to machine learning and deep learning approaches. Here we will demonstrate a neural network-based approach to this task by building an ensemble of 1D CNN classifiers and a final classifier of selection using logistic regression, random forest or support vector machine, and make the conclusions of the comparison with other approaches.

• Journal of Biomedical Engineering Research
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• v.16 no.1
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• pp.95-100
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• 1995

In this study, we have evaluated the effect of amplitude and frequency perturbation of EGG signal for single vowels associated with laryngeal pathology. The normal EGG signal was properly characterized by an autoregressive model which has an optimal order of ninth using the parametric method. This can be analyzed by determining the transfer function. Perturbations in the fundamental pitch and in the peak amplitude of EGG signal measured with a four-electrode system using the modulation/demodulation techniques were investigated for the purpose of developing a decision criteria for the laryngeal function analysis. The abnormal EGG signal has nonperiodic and unstable characteristics. It can be discriminated by the calculation of opening and closing time of glottis using the EGG signal. In case of normal and abnormal subjects, m$\pm$0.5*sd was discriminating line for frequency perturbation and m$\pm$2*sd for normal amplitude perturbations, respectively. Also, The normal and abnormal cases of the subjects can be discriminated effectively using the pattern of attractor derived with Hilbert transform of EGG signal.

• International Journal of Highway Engineering
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• v.14 no.2
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• pp.175-181
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• 2012

Under unsaturated capacity conditions with balanced approach flows, roundabout gives less delay and queue length than existing signalized intersections; however, over capacity conditions with unbalanced approach flows(flow above 450 pcu/h/lane), roundabouts efficiency drops due to the short gap between entering vehicles and circulating vehicles. This study provides a roundabout Signal Metering transfer standard and operation method. In this study, a four-way-approach with one-lane roundabout is selected to compare the Signal Metering performance for the case of unbalanced flow conditions. The performance is evaluated by using SIDRA software in terms of average delay and queue length. The result shows that the Signal Metering provides substantial improvements for the case of total approach flow is 1,800~2,000 pcu/h in which the main approach flow ratio is 60~70% gives 30~40% less delay and 30~60% less queue length than normal roundabout operation. Also, it is approved that operational performance saving can be achieved when the Metered Approach is selected adjoining to the main approach in pair.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.4
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• pp.342-348
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• 2013

In this paper, the evaluation method for the responsivity and noise characteristics of an infrared thermal imaging camera was presented. Signal transfer function and noise equivalent temperature difference of the infrared thermal imaging camera were obtained by using a differential mode blackbody that is able to control the temperature difference ${\Delta}$T between an infrared target and its background. And we verified the suitability of our evaluation method through comparison between the found noise equivalent temperature difference and the specification of the camera. In addition, the difference of 0.01 K of the two noise equivalent temperature differences calculated from with and without nonuniformity correction suggests that the nonuniformity correction is essential process for the evaluation of the infrared thermal imaging camera.

• Journal of Advanced Marine Engineering and Technology
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• v.3 no.1
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• pp.19-31
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• 1979

Recently the adaptive control system, which keeps the control system always optimal by adjusting the control parameters automatically according to the variations of the plant parameters, have become very important in the field of control engineering. The adaptive control systems are usally composed of the plant identification, the decision of the optimal control parameters, and the adjustment of the control parameters. This paper deals with a method of the adaptive control system when PI or PID controller is used in the feed back control system. Its controlled object (the plant) is assumed to be described by the transfer function of $\frac{ke^{-LS}}{1+TS}$ where k, T and L are steady state gain, time constant and pure dead time respectively, and their values are variable in accordance with the change of environmental circumstance. It has been known that a pseudo-random binary signal is quite effective for the measurement of an impulse response of a plant. In adaptive control systems, however, the impulse response itself is not appropriate to determine the control parameters. In this paper, the authors propose a method to estimate directly the parameters of the plant k, T and L by means of the correlation technique using 3 level M-sequence signal as a test signal. The authors also propose a method to determine the optimal parameters of the PI or PID controller in the sense of minimizing the square integral of the control error in the feed back control system, and the values of the optimal parameters are computed numerically for various values of T and L, and the results are examined and compared with those of the conventional methods. Finally the above-mentioned two methods are combined and an algorithm to struct an adaptive control system is suggested. The experiments for the indicial responses by means of both the model of the temperature control system using SCR actuater and the analog simulations have shown good results as expected, and the effectiveness of the proposed method is verified. The M-sequence generator and the time delay circuit, which are manufactured for the experiments, are operated in quite a good condition.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.483-490
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• 1992

In order to understand the transfer behavior of a particular gene in water environments, kanamycin resistance ($Km^r$) gene was tracked by Southern hybridization with DNA probe in its conjugal transfer. A $Km^r$ natural bacterial isolate and genetically modified microorganisms (GMMs) constructed from the isolate were used as donor for conjugal transfer of the $Km^r$ gene. The transfer frequencies of the $Km^r$ gene from GMM strains were generally 10 to 100 times higher than those from the natural isolate. The conjugants obtained from GMM strains in LB broth had more plasmids newly appeared, and particularly the conjugants in A Wand FW waters revealed more rearrangement in their plasmids as a function of conjugation time. When plasmids of the conjugants obtained in LB broth were Southern hybridized with DNA probe of the $Km^r$ gene, the $Km^r$ plasmids in the conjugants were detected at the same position of the plasmids in donor cells, in spite of the fact that the plasmids were highly rearranged in conjugant cells. But the $Km^r$ plasmids in the donor of DKI and DKC601, and DKC600 were not identified in the conjugants obtained after 50 h conjugation in AW and after 30 h in AW, respectively. The size of the $Km^r$ plasmids showing hybridization signal were a little changed in the conjugants obtained in A Wand FW waters. Therefore, the method of Southern hybridization with DNA probe was proved to be very specific and useful for tracking of particular genes in water environments.

• International Journal of Oral Biology
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• v.32 no.1
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• pp.7-11
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• 2007

It is difficult to introduce DNA in non-invasive manner into oral cancer cells as well as primary cells for gene manipulation and expression in vivo. So far, several methods for a gene delivery have been performed to solve this problem. Magnetofection is one of the recent methods for gene transfer, and nanoparticles are applied under a magnetic field for DNA delivery. We investigated whether the magnetofection increases the efficiency of a gene delivery into several oral cell lines. By using a plasmid coding the green fluorescent protein (GFP), the efficiency of gene transfer by magnetofection was compared with those by using the calcium phosphate and the commercial transfection agent. Indeed, the magnetofection increased the green fluorescent signal in cells, suggested that this method apparently enhance the efficiency of gene delivery without any defects in various oral cancer cell lines. Finally, we have shown that magnetofection can be a useful technique for gene delivery to difficult-to-transfect cells to perform a functional study of genes in vivo.

• Journal of the Ergonomics Society of Korea
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• v.22 no.4
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• pp.1-13
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• 2003

This study has investigated psychological responses to various TV advertisements by using EEG(electroencephalogram). In particular, it was assumed that the brain wave would show different patterns depending upon the style of the advertisement that could be categorized into two such as 'information transfer' type and 'emotional reaction' type. Ten healthy males participated in the experiment. EEG signal was extracted from six lobes such as right and left frontal, right and left occipital, right and left temporal while the subjects were watching TV advertisements. Alpha and beta relative power spectrum, and beta/alpha parameter were calculated to compare two kinds of advertisement each other. Additionally, subjective questionnaire was used to examine subject's response by using adjective words and preference test. In result, significant differences were found in left frontal and right occipital lobe in terms of beta/alpha between two different advertisements. And, subjects showed different preference between two advertisements. It was shown that the current method could analyze the brain reaction to advertisement quantitatively, that presented the possibility of using it to marketing research.