• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.534-538
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• 2009

Japanese apricot (Prunus mume) "Okboseok" was released from a cross between "Nanko" and "Yoseibai" in 1993 at the Pear Research Station of National Institute of Horticultural and Herbal Science, Rural Development Administration. It was preliminarily selected in 2001 and named in 2006. It produces high yield with a flesh about average 88.3% of fruit, although the fruit size is small (approximately 14.0g). Horticultural and physiological harvest time of this cultivar is mid and late June respectively. It has single flowers with pink petal color and its flowering time is about 4 days later than that of "Nanko". Its fruit is tolerant to bacterial shot hole (Xanthomonas arboricola pv. Pruni) and pear scab (Venturia nashicola). "Okboseok" has abundant pollen grains (about 96 mg/100 flowers), thus it could be a pollinizer. To obtain stable yields, however, its compatibility with major cultivars is needed to be confirmed as pollinizer cultivar. "Okboseok" is recommended for being preserved in sugar and liquor.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.1
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• pp.43-52
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• 2010

In this paper, the mobile-WiMAX (m-WiMAX) using the Smart antenna technique is implemented. Experiments are performed to compare Smart antenna system with conventional single antenna system. To implement the m-WiMAX smart antenna system there are many considerations, key issues of which are symbol time acquisition, beamforming, calibration. In the paper, symbol time acquisition, beamforming, calibration are implemented in WiMAX Smart antenna system and we verified that Smart antenna system is superior to single antenna system. The experimental results show 5.5 dB performance enhancement of implemented Smart antenna system in throughput compared with a single antenna system. The experimental result is almost same as theoretical result of 6 dB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.11
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• pp.2298-2304
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• 2015

In this paper, we provide a new approach which optimizes the vertical tilting angle of the base station for multi-cell multiple-input single-output (MISO) downlink active antenna systems (AAS). Instead of the conventional optimal algorithm which requires an exhaustive search, we propose simple and near optimal algorithms. First, we represent a large system approximation based vertical beamforming algorithm which is applied to the average sum rate by using the random matrix theory. Next, we suggest a signal-to-leakage-and-noise ratio (SLNR) based vertical beamforming algorithm which simplifies the optimization problem considerably. In the simulation results, we demonstrate that the performance of the proposed algorithms is near close to the exhaustive search algorithm with substantially reduced complexity.

• Journal of Ocean Engineering and Technology
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• v.12 no.3 s.29
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• pp.1-8
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• 1998

The purpose of this study is to determine the distribution of the suspended matter caused by dredging at the northeastern part of Kwangyang Bay and to determine the effect of the single silt protector for it. According to the direction of the tidal current, six sampling stations were chosen from the dredging site to the southeast. At the high tide, the high concentration of the suspended matter was observed below the mid-depth near the dredging site. As the tidal currents were stronger. its concentrations below the mid-depth at the inner stations of the single silt protector were rapidly increased, but those of the outer stations did not show any significant change. The concentrations at the inner stations of the silt protector at that time were from 20~140mg/l and those of the outer stations, which was only about 30 m apart from the inner station, were from 20~30mg/l. It suggests that the large amount of suspended matter caused by dredging were moved to the inner stations near the silt protector at the ebb tide and that the silt protector is very effective for the suspended matter.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.389-392
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• 2008

This paper predicts the changes of natural frequencies due to the changes of mass at different point mass stations by using iterative calculation Transfer Matrices Method for different boundary conditions of a single beam structure (fixed-free and fixed-fixed beam). Firstly, the first three natural frequencies of an original beam are obtained using Transfer Matrices Method to verify the accuracy of the obtained results. The results are then compared with the exact solutions before purposely changing the parameter of mass. Both beams are modeled as discrete continuous systems with six-lumped-mass system. A single beam is broken down into a point mass and a massless beam which represent a single station and expressed in matrix form. The assembled matrices are used to determine the value of natural frequencies using numerical interpolation method corresponding to their mode number by manipulating some elements in the assembled matrix.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.4
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• pp.1-11
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• 1997

In this paper, modeling of the communication channel occupancy characteristics at the base station in the wide area radio trunking syste has been performed. Using the results, mathematical analysis for the switching capacity at the network switch has also been done. Specificatlly, we propose a G/M/m queueing model for the single service area modeling, and analyze changes in call blockingprobabilities accoridng to changes in the burstness characteristics of group paging calls. As a result, we have observe dthat the channel occupancy variations become larger as the burstness characteristics become more apparent, to make the call blocking probability higher. Next, based on the single service area analysis, we have anayzed mathematically the average switching capacity required to serve mobile subscribers for a wide area radio trunking sytem, where multiple switching port assignments are required when the people in the same group are distributed over several base stations. Accordingly, we have observed that the average and the variance of switching channel occupancy are closely related to the mobility characteristics of subscribers, and that we need a netowrk switch having bigger capacity as subscribers show wider distribution. Especially, with the call dropping probability within 0.2%, a switch having about 5 to 6 times bigger can be required, compared with the one when the mobility of subscribers is mostly restricte dto a single service area.

• Journal of the Korean housing association
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• v.22 no.4
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• pp.93-102
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• 2011

The purpose of this study is to suggest unit design considerations for college student's rental houses. To achieve this purpose, life pattern, residential space usage and housing needs were investigated. Data were collected by in-person interviews. Interview participants were 37 single undergraduate students living near the Shinchon station subway line 2. Subjects were selected by housing types-a Gosiwon, a boarding house or an one-room house-. Qualitative approaching method was used, and quantitative analysis was additionally employed to count keyword found during the interviews. SPSS window version 14.0 was used for the descriptive statistics and the analysis of the items with multi-response analysis. The major findings are as follows; a personal space for each resident with a common kitchen and a bathroom was mostly desired for the unit. Therefore, Two diagrams would be used as examples to explain the new concept of unit planning.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.6
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• pp.437-452
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• 2002

The Metropolitan Tracer Experiment (METREX) was performed over the Washington, D.C. area using two inert, non-deposition perfluorocarbon gases for over 1 year period (November 1983∼December 1984). Two perfluorocarbon gas tracers (PDCH, PMCH) were released simultaneously at intervals of every 36 hours for 6 hours, regardless of the meteorological conditions in metropolitan area. Samples were collected continuously for 8 hours at a central downtown and two adjacent suburban locations. Monthly air samples were collected at 93 sites across the whole region (at urban, suburban, and rural locations). The purpose of this study is to simulate INPUFF and ISCST model using METREX data, and to compare calculated and observed concentrations. In the case of INPUFF simulation, two meteorological input data were used. One is result data from wind field model which was calculated by diagnostic wind model (DWM), the other is meteorological data observed at single station. Here, three kinds of model calculation were performed during April and July 1984; they include (1) INPUFF model using DWM data (2) INPUFF model using single meteorological data (3) ISCST model. The monthly average concentration data were used for statistic analysis and to draw their horizontal distribution patterns. Eight-hour-averaged concentration was used to describe movement of puff during the episode period. The results showed that the concentrations calculated by puff model (INPUFF) were better than plume model (ISCST). In the case of puff model (INPUFF), a model run using wind field data produced better results than that derived by single meteorological data.

• Journal of Communications and Networks
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• v.13 no.4
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• pp.327-338
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• 2011

With the incitation to reduce power consumption and the aggressive reuse of spectral resources, there is an inevitable trend towards the deployment of small-cell networks by decomposing a traditional single-tier network into a multi-tier network with very high throughput per network area. However, this cell size reduction increases the complexity of network operation and the severity of cross-tier interference. In this paper, we consider a downlink two-tier network comprising of a multiple-antenna macrocell base station and a single femtocell access point, each serving multiples users with a single antenna. In this scenario, we treat the following beamforming optimization problems: i) Total transmit power minimization problem; ii) mean-square error balancing problem; and iii) interference power minimization problem. In the presence of perfect channel state information (CSI), we formulate the optimization algorithms in a centralized manner and determine the optimal beamformers using standard convex optimization techniques. In addition, we propose semi-decentralized algorithms to overcome the drawback of centralized design by introducing the signal-to-leakage plus noise ratio criteria. Taking into account imperfect CSI for both centralized and semi-decentralized approaches, we also propose robust algorithms tailored by the worst-case design to mitigate the effect of channel uncertainty. Finally, numerical results are presented to validate our proposed algorithms.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.1
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• pp.13-19
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• 2002

In a different way of satellite image or aerial photo, the image acquired by terrestrial photogrammetry has to go through complicated management according to the desired precision and analysis range. In this study, digital surface model and ortho image for cultural asset, terrestrial structures, were made by reflectorless total station in order to increase the application of single photo, and that was analyzed and compared with the method using stereo image. Single photo is expected to be utilized as the measuring method for drawing cultural assets or examining the stability of slope in which high precision doesn't need by performing the various geometric and visual analysis using ortho image made by excluding the difficulties of acquisition and plotting of stereo image.