• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.6
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• pp.757-763
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• 2018

It is very difficult to achieve sufficient data rate and required quality of service due to the time-varying nature of the radio channel and various jammers such as path loss, delay, Doppler, shadowing and interference. Especially, the propagation path between the transmitting antenna and the tracking antenna mounted on the fuselage during the test and evaluation of the projectile system considered in this paper is based on the rapid movement of the projectile, the interference due to multipath fading due to the terrain, The propagation path may be blocked. In order to effectively improve the multipath fading occurring in the wireless communication system, a diversity combiner technique is required. In this paper, to derive the design and improvement schemes for the space diversity combiner technique among the diversity combiner schemes, the BER performance of maximum ratio combining (MRC) and selection combining (SC) In an adaptive SC / MRC diversity combiner that operates with MRC when it is lower than the specified threshold criterion when comparing the SNR between two signals received from the channel and operates with SC at high and combines the two received signals The BER performance of the system was compared and analyzed.

• 재활복지
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• v.22 no.3
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• pp.189-208
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• 2018

This case study investigated the changes in speech intelligibility of patients with head and neck cancers who participated in a therapeutic singing-based intervention. Three patients received a total of twelve 30-minute individual sessions. The intervention consisted of three steps: movements for relaxing breathing muscles, vocalization for increasing the range of articulatory movements, and therapeutic singing. In order to examine the changes in speech intelligibility, the voice quality parameters, diadochokinesis (DDK) and the quadrangle vowel space area (VSA) were measured at pre- and posttest. The recording of what each patient read a written paragraph, which were transcribed by blinded assessors, were also analyzed. The results demonstrated that all of the patients showed positive changes in the voice quality, the rate of repetitive syllable production measured by DDK, and the articulatory working space measured by VSA. Along with these measured changes, increases in positive mood and rehabilitation motivation reported by the patients support that the therapeutic singing-based intervention could induce meaningful changes in terms of speech intelligibility from patients with head and neck cancers. Given that this study was conducted with a small sample size, suggestions for further investigation on the effects of the intervention were also presented.

• Journal of Climate Change Research
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• v.4 no.2
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• pp.189-199
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• 2013

Using meteorological data collected from 60 observation stations during the last 38 years from 1973 through 2010, we have analysed the occurrence frequencies of abnormally low or high temperature leading to agrometeorological disasters. The analysis was made for 20 agro-climatic zones that had already been divided by the Rural Development Administration before. Since 1973, there have been an average of 1.8 frequency of abnormal air temperature occurrence per year. The frequency of abnormally high temperature occurrence has increased from an average of 0.2 per year in 1970s to 1.0 in 2000s. However, the frequency of abnormally low temperature occurrence has decreased from an average of 2.06 per year in 1970s to 0.63 in 2000s, which might be able to explain a recent global warming. The highest frequency of abnormally high temperature occurrence appeared in Taebaek Alpine zone with an average of 0.76 frequency per year. Meanwhile, abnormally low temperature was the highest in Western Sobaek Inland zone with an average of 1.43 frequency per year.

• Journal of Korea Water Resources Association
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• v.52 no.2
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• pp.163-172
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• 2019

The linear and cross-sectional shapes of the natural river channel are subjected to continuous changes in time and space due to the interaction with the flow of water and sediment transport. This study aims to investigate the morphological characteristics and change patterns of river channel quantitatively for the middle reach of Nakdong River, which has undergone large scale riverbed dredging and construction work, as Four Major River Restoration Project. A series of bathymetry and near-river survey has been conducted to obtain the detailed terrain information for the study area. The properties related to the linear and cross-sectional characteristics of river channel have been calculated based on the filed survey data and analyzed with comparing the survey data obtained in 2012 for the project completion. Since there has not been enough time for meaningful terrain change to take place, it was not possible to extract special tendency in the degree and aspect of terrain change. However, it is necessary to make regular examinations to the patterns and degree of river channel change using the proposed methodology.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.169-180
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• 2018

White light-emitting diodes (LEDs) are more economical than fluorescent lights, and provide high brightness, a high lifetime expectancy, and greater durability. As LEDs are closely connected with people's daily lives, dimming control of LED is an important component in providing energy savings and improving quality of life. In visible light communications systems using these LEDs, multiple input multiple output (MIMO) technology has attracted a lot of attention, in that it can attain the channel capacity in proportion to the number of antennas. This paper analyzes the power performance of three kinds of modulation in visible light communications (VLC) systems applied space-time block code (STBC) techniques. The modulation schemes are return-to-zero on-off keying (RZ-OOK), variable pulse position modulation (VPPM), and overlapping pulse position modulation (OPPM), and dimming control was applied. The power requirements and power consumption were used as metrics to compare the power efficiency in $2{\times}2$ STBC-VLC environments under the three kinds of modulation. We confirm that dimming control affects the communications performance of each modulation scheme. VPPM showed greater consumption among the three modulations, and OPPM showed energy savings comparable to VPPM.

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.1101-1117
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• 2018

The clear sky radiance (CSR) is one of the baseline products of the Himawari-8 which was launched on October, 2014. The CSR contributes to numerical weather prediction (NWP) accuracy through the data assimilation; especially water vapor channel CSR has good impact on the forecast in high level atmosphere. The focus of this study is the quality analysis of the CSR of the Himawari-8 geostationary satellite. We used the operational CSR (or clear sky brightness temperature) products in JMA (Japan Meteorological Agency) as observation data; for a background field, we employed the CSR simulated using the Radiative Transfer for TOVS (RTTOV) with the atmospheric state from the global model of KMA (Korea Meteorological Administration). We investigated data characteristics and analyzed observation minus background statistics of each channel with respect to regional and seasonal variability. Overall results for the analysis period showed that the water vapor channels (6.2, 6.9, and $7.3{\mu}m$) had a positive mean bias where as the window channels(10.4, 11.2, and $12.4{\mu}m$) had a negative mean bias. The magnitude of biases and Uncertainty result varied with the regional and the seasonal conditions, thus these should be taken into account when using CSR data. This study is helpful for the pre-processing of Himawari-8/Advanced Himawari Imager (AHI) CSR data assimilation. Furthermore, this study also can contribute to preparing for the utilization of products from the Geo-Kompsat-2A (GK-2A), which will be launched in 2018 by the National Meteorological Satellite Center (NMSC) of KMA.

• Journal of agriculture & life science
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• v.52 no.6
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• pp.89-101
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• 2018

The purpose of this study was to evaluate the variation of water quality in the Nakdong River by the Four major river projects. For this purpose, the nearest upstream water quality monitoring stations were selected and water quality data such as BOD, COD, SS, TN, TP, and TOC were collected for the before Four major river project(from January 2003 to November 2008), during the project(from September 2008 to April 2012) and after the project(from May 2012 to September 2017). As a result, the concentration of DO, BOD, COD, TN, and TOC after the project tend to be higher than the before project period. On the other hand, the SS and T-P values decreased after the project. Spatial analysis of BOD, COD, and TOC, which have large changes in water quality factor, by water quality grade, showed a tendency that water quality grade after the project was worse than before the project.

• Geophysics and Geophysical Exploration
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• v.21 no.4
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• pp.255-261
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• 2018

The purpose of this study was to obtain a large amount of saline groundwater around coastal aquaculture farms. Thus, we have proposed a method for evaluating the potential amount of saline groundwater resources through the combined analysis of geophysical methods. Refraction seismic survey and electrical resistivity survey were conducted in the vicinity of fish farm at Hadong, Gyeongnam Province. As the result, the velocity of layer in the range of 900 ~ 2,400 m/s was found to be saltwater aquifer with high water content. Geological drilling investigation and analysis of soil samples also showed that the soil at study area was the same as the texture of sandy loam layer in agricultural radial collector wells installed by KRC (Korea Rural Community Corporation). Futhermore, the study area turned out to be quite possible to develop saline groundwater from the coastal shallow aquifer. Therefore, parallel analysis of refraction seismic surveys and electrical resistivity surveys at coastal area are expected to be very useful for the detection of the aquifer composed of sand and gravel layers with high porosity in sandy sedimentary layers along the coastal area.

• Journal of Cadastre & Land InformatiX
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• v.48 no.2
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• pp.121-135
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• 2018

The ministry of land, Infrastructure and transport has revised the "National Land Planning and Utilization Act" in 2012. As a result, the regulation of floor area ratio for land covering two or more zoning area has been changed. This study conducted an analysis of the policy effects of changes in the criteria for the application of the floor area ratio by revising the "National Land Planning and Utilization Act". Land covering two or more zoning area means a street side commercial area and street side residential area that is generally understood. This study analyzed the policy effects in Gangnam-gu which has relatively large areas of street side commercial area and street side residential area. The 468 office building transaction cases were analyzed in Gangnam-gu from 2007 to 2017. The result shows that the office building, which has received incentive for policy changes, reported a 19.08% rise in price compared to the one that did not. It means that the economic effects of change of application standard were significant. The existing policy also served as a restriction on land use by landowners, which in turn contributed to the devaluation of the asset's intrinsic value. Therefore, this study may have contributed to the rational use of land and to provide an empirical basis for the change in policy to be assessed for its intrinsic value.

• The Journal of the Korea Contents Association
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• v.18 no.12
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• pp.332-342
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• 2018

This study is aimed at suggesting information about technical choices for designing LED camping lights based on emotional lighting contents of integrated IOT and design areas which take a central role in creation and knowledge based industries and the procedure for materializing them. 'i-Light,' a portable LED camping light, is 'connected lighting' connecting men, space and emotion and a smart camping light based on IOT and emotional lighting contents. 'i-Light' has two functions. One is about lighting for adjusting color and color temperature naturally and the other is about safety for detecting harmful gases. 'i-Light' also has various emotional functions for experiencing interaction and taste of light. For the purpose, portable LED camping lights were designed, first of all, and then a highly color rendering/full-color lighting module, a smart sensor module and an IOT device platform were developed. In addition, efforts were made to establish detailed data about emotional lighting contents and to develop a Web application based on them. Finally, prototypes of portable LED camping lights were made to get a test bench and usability evaluation from related organizations. According to the results, all of 12 developed emotional lighting contents and three IOT safety sensors were suitable and prototypes were satisfactory. This paper will suggest a direction about actual technical choices for development of contents and products integrating artificial intelligence and big data and about the procedure for materializing them.