• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.4
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• pp.762-768
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• 2015

D2D communication as an underlaying LTE-Advanced network has proven to be efficient in improving the network performance and decreasing the traffic load of eNodeB(enhanced NodeB). However large amount of interference can be caused by sharing the resources between the cellular users and D2D pairs. So, a resource allocation for D2D communication to coordinate the interference is necessary. Related works for resource allocation that D2D can reuse the resources of more than one cellular user with best CQI(Channel Quality Indicator) have been proposed. D2D communications may still cause interference to the primary cellular network when radio resource are shared between them. To avoid this problem, we propose a radio resource allocation algorithm with low computational complexity for D2D communication in OFDM-based wireless cellular networks. Unlike the previous works, the proposed algorithm utilizes unused ones of the whole resource. The unused resource allocate to on D2D pair can be shared only with other D2D pairs. In other words, if the distance between the D2D pairs is sufficient, we allowed more than two D2D pairs to share the same resources. The simulation results have proven that the proposed algorithm has up to 11 times lower computational complexity than the compared one according to the number of D2D.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9B
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• pp.876-882
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• 2009

In this paper, we propose a sub-cell coverage control algorithm for enhancement of the cell throughput in OFDMA based relay systems. Relay station (RS) is exploited for improved quality of the received signal in cellular communication systems, especially in shadow areas. However, since a RS requires additional radio resource consumption for the link between the base station (BS) and the RS, we have to carefully control the coverage areas if a mobile station (MS) is serviced via the BS or the RS considering the cell throughput. We consider radio resource reuse as well for the sub-cell coverage configuration by applying various reuse patterns between RSs. We also consider a time varying system by adaptively changing the threshold for coverage depending on the MSs' traffic in the cell. We initially determine the sub-cell coverage of the system depending on the ratio of received signal-interference-noise-ratio (SINR) of the MS from the BS and RSs, respectively. Then, the "sub-cell coverage threshold" varies based on the "effective transmitted bits per sub-channel" with time. Simulation result shows that the proposed "time varying coverage control algorithm" leads to throughput improvement compared to the fixed sub-cell coverage configuration.

• Journal of Digital Contents Society
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• v.17 no.3
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• pp.119-133
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• 2016

This paper is designed to study how public values of viewers impact on the necessity of public service broadcasters and the willingness to payment of TV license fee based on the public-opinion survey regarding raising KBS TV license fee which was submitted to the National Assembly in 2013. To investigate this influence, seven main projects presented by KBS are classified into five public values of public (service) broadcasters such as quality, diversity, universality, social value and global value. The seven key performance tasks were presented by KBS. The study results are summarized as follows. Firstly, the survey group who selected the digital welfare enlargement by free terrestrial multi-channel broadcasting among public values recognized as highest the necessity of public service broadcasting as the most highly. Secondly, regarding the question of raising license fee, 72.4 percent of respondents were in favor of 1,000 won and 43.9 percent of respondents were in favor of 1,500 won. The result of this study shows that public service broadcasting has the possibility of securing the legitimacy of license fee policy when public service broadcasters faithfully carry out the five public values as above.

• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.55-65
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• 2008

At these information age when the importance of news is of particular emphasis, the field of image-production for the news are being made rapid progressive by high-tech like multi-media, multi-channel digital system. Even experts who have engaged in the work of broadcasting in th field for a long time are perplexed with rapid development in Broadcasting equipments and expression techniques. The field of TV is characterized by the speed of change and the desire of viewers for new and interesting video images. The image expression system applying image line has ever existed as one of conventional image expression methods. Obsolete and old image expressions are paling into significance for viewers who want to access more information in a short time. but The change of image expression systems due to the progressive stream of time has forced existing imaginary to be changed constantly to accommodate the changing interests and expectations of the viewers. Therefore, in this treatise, we need a broad interpretation about the direction of this imaginary line for TV news image in that existing systems of image producing haven’t also been changed and adapted to the stream of time. In these days, image is defined as not only video, but also audio. also We need to reduce the confusion concerning the imaginary line and contribute to a correct understanding images of TV news for not only customers but also producer by extending and applying the concept of imaginary line to image producing.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.1
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• pp.71-79
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• 2011

The objective of the imaging pipeline is to transform the original scene into a display image that appear similar, Generally, gamma adjustment or histogram-based method is modified to improve the contrast and detail. However, this is insufficient as the intensity and the chromaticity of illumination vary with geometric position. Thus, MSR (Multi-Scale Retinex) has been proposed. the MSR is based on a channel-independent logarithm, and it is dependent on the scale of the Gaussian filter, which varies according to input image. Therefore, after correcting the color, image quality degradations, such as halo, graying-out, and dominated color, may occur. Accordingly, this paper presents a novel color correction method using a modified image formation model in which the image is divided into three components such as global illumination, local illumination, and reflectance. The global illumination is obtained through Gaussian filtering of the original image, and the local illumination is estimated by using JND-based adaptive filter. Thereafter, the reflectance is estimated by dividing the original image by the estimated global and the local illumination to remove the influence of the illumination effects. The output image is obtained based on sRGB color representation. The experiment results show that the proposed method yields better performance of color correction over the conventional methods.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.11
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• pp.226-233
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• 2013

In this study, In Laver's automatic drying device, laver thickness measurement and control devices that are associated with. Disconnect the water and steam, after put a certain amount of the mixture(water and laver) in the mold. In process, Laver of the size and thickness (weight) to determine, constant light source to detect and image LED Lamp occur Vision Sensor (Camera) prepare, then the values of these state of the image is transmitted in real time embedded computers. Built-in measurement and control with the purpose of the application of each of the channels separately provided measurements are displayed on a monitor, And servo signals sent to each of the channels and it become so set function should be. In this paper, the laver drying device, prior to the laver thickness measurement and control devices that rely on the experience of existing workers directly laver manually adjust the thickness of the lever, but the lever by each channel relative to the actuator by installing was to improve the quality. In addition, The effect of productivity gains and labor savings are.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.2C
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• pp.192-199
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• 2008

In ultra-wideband (UWB) systems, conventionally, the synchronization is to align time phases of a locally generated template and any of multipath components to within an allowable range. However, the synchronization with a low-power multipath component could incur significant performance degradation in receiver operation (e.g., detection) after the synchronization. On the other hand, the synchronization with a high-power multipath component can improve the performance in receiver operation after the synchronization. Generally, the first one among multipath components has the largest power. Thus, the synchronization with the first path component can make better performance than that with low-power component in receiver operation after the synchronization, Based on which, we first propose an optimal decision rule based on a maximum likelihood (ML) approach, and then, develope a simpler suboptimal decision rule for selecting the first path component. Simulation results show that the system has good demodulation performance, which uses new synchronization definition and the proposed decision rules have better performance than that of the conventional decision rule in UWB multipath channels. Between macroblocks in the previous and the current frame. On video samples with high motion and scene change cases, experimental results show that (1) the proposed algorithm adapts the encoded bitstream to limited channel capacity, while existing algorithms abruptly excess the limit bit rate; (2) the proposed algorithm improves picture quality with $0.4{\sim}0.9$dB in average.

• Journal of Digital Convergence
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• v.11 no.7
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• pp.237-242
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• 2013

When abdomen and pelvic were scanned with 128 channel MDCT, the gonadal exposure dose was measured with and without gonadal shield and the obtained images were evaluated. As a result, during abdominal MDCT scan, the gonadal exposure dose was measured $16.5{\pm}0.5$ mGy when the gonad shield was not used, and it was $7.5{\pm}0.3$ mGy when the large gonad shield($650m^2$) was used, which showed the effect of reduction in the gonadal exposure dose by 54%. During pelvic MDCT scan, the gonadal exposure dose was $9.5{\pm}0.3$ mGy when the gonad shield was not used, and it was $2.8{\pm}0.2$ mGy when the large gonard shield($650m^2$) was used, which showed the effect of reduction in the gonadal exposure dose by 70%. The images were obtained when using the gonad shield and when not using it during MDCT scan, and as a result of analyzing them with 5-point Likert scale, in the abdominal image, it was 4.1 points irrespective of whether using the gonad shield or not. And also, in pelvic scan, it was 1.2 points when the gonad shield was used, and 4.1 points when it was not used. With the results above, it is considered that during the abdominal 128-MDCT scan, by using the gonad shield, the images should be obtained without being degraded and the exposure dose must be reduced.

• Polymer(Korea)
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• v.33 no.6
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• pp.561-568
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• 2009

Small injection molded articles are generally molded by multi-cavity injection molding. The most important thing in multi-cavity molding is flow imbalance among the cavities because it affects the physical property and the quality of products. The cavity filling balance can be achieved by flow balance in the runner through the thermal balance. In this study, novel screw type runner or helical type runner has been developed for the flow balance in the runner and performed experiment and computer simulation. Flow balance has been observed using various screw type runners for several resins such as amorphous and crystalline polymers including low and high viscosities grades. Flow balance experiments have been performed for various injection speeds since the flow balance can be affected by injection speed among the injection conditions. Experimental results have been compared with computational results and they showed good agreement. The cavity filling balance can be achieved by the screw runner where the temperature distribution is uniform through the circulation flow along the screw channel in the screw runner. It has been verified that the novel screw runner is very effective device in flow balance in the multi-cavity injection molding. cavity filling imbalance, multi-cavity injection molding, runner design, screw runner, thermal balance.

• 한국지구물리탐사학회:학술대회논문집
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• 1999.08a
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• pp.48-64
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• 1999

For quantitative evaluation of geotechnical engineering properties such as rippability and diggability, clear interpretation on the subsurface velocity structures should be preceded by figuring out top soil, weathered and soft rock layers, shape of basement, fracture zones, geologic boundary and etc. from the seismic refraction data. It is very important to set up suitable field parameters, which are the configuration of profile and its length, spacings of geophones and sources and topographic conditions, for increasing field data quality Geophone spacing of 3 to 5m is recommended in the land slope area for house land development and 5 to 10m in the tunnel site. In refraction tomography technique, the number of source points should be more than a half of available channel number of instrument, which can make topographic effect ignorable. Compared with core logging data, it is shown that the velocity range of the soil is less than 700m/s, weathered rock 700${\~}$1,200m/s, soft rock 1,200${\~}$1,800m/s. And the upper limit of P-wave velocity for rippability is estimated 1,200 to 1,800m/s in land slope area of gneiss. In case of tunnel site, it is recommended in tunnel design and construction to consider that tunnel is in contact with soft rock layer where three lineaments intersecting each other are recognized from the results of the other survey.