• Journal of the Korean housing association
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• v.27 no.5
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• pp.45-54
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• 2016

This study aims to verify the effects of the apartment office managers' servant leadership on the residents' satisfactions and housing management company contract renewal ratio, and to examine whether the number of apartment units and the apartments' average size have the moderating effects upon the relationship between servant leadership and the residents's satisfaction and housing management company contract renewal ratio. For the purpose of testing the hypotheses, the questionnaire survey was conducted targeting 1,000 apartment office staffs and 8,000 apartment residents of 200 apartment complex in the region of Ulsan, Kyungnam, and Busan, and the statistical analyses were carried out for the useful questionnaires of 961 apartment office staffs and 7,119 apartment residents. The main results are as follows: First, the higher the office managers servant leadership is, the higher the residents' satisfactions. Second, the number of apartment units and the average size have moderating effects on the relationship between the office managers' servant leadership and housing management company contract renewal ratio. Finally, the summary, implications, and limitations of this study, and the future research direction were discussed in the conclusion.

• Journal of Communications and Networks
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• v.13 no.3
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• pp.240-249
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• 2011

Cooperative diversity protocols have attracted a great deal of attention since they are thought to be capable of providing diversity multiplexing tradeoff among single antenna wireless devices. In the high signal-to-noise ratio (SNR) region, cooperation is rarely required; hence, the spectral efficiency of the cooperative protocol can be improved by applying a proper cooperation selection technique. In this paper, we present a simple "cooperation selection" technique based on instantaneous channel measurement to improve the spectral efficiency of cooperative protocols. We show that the same instantaneous channel measurement can also be used for relay selection. In this paper two protocols are proposed-proactive and reactive; the selection of one of these protocols depends on whether the decision of cooperation selection is made before or after the transmission of the source. These protocols can successfully select cooperation along with the best relay from a set of available M relays. If the instantaneous source-to-destination channel is strong enough to support the system requirements, then the source simply transmits to the destination as a noncooperative direct transmission; otherwise, a cooperative transmission with the help of the selected best relay is chosen by the system. Analysis and simulation results show that these protocols can achieve higher order diversity with improved spectral efficiency, i.e., a higher diversity-multiplexing tradeoff in a slow-fading environment.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.4
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• pp.297-305
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• 2010

Employment number by areas is composed of various factors for groups and time series. In this paper, we use the panel data for finding various variables and using this, we analyzed the factors that is major influence to employment number by areas. For analysis we looked at employment number by areas, the region for analysis consist of seven groups, that is, the metropolitan city(such as Busan, Daegu, Incheon, Gwangiu, Daejeon, Ulsan.) and Seoul. Analyzing period be formed over a 63 time points(2005.01.- 2010.03). We examined the data in relation to the employment number by occupational job, unemployment rate, monthly household income, preceding business composite index, consumer price index, composite stock price index. In looking at the factors which determine employment number by areas job, evidence was produced supporting the hypothesis that there is a significant negative relationship between unemployment rate and monthly household income the consumer price index. The consumer price index and composite stock price index are significant positive relationship, preceding business composite index is positive relationship, it are not significant variables in terms of employment number by areas job.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.23-28
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• 2013

In this paper, we propose a simple bidirectional transmission protocol using network coding and digital Fountain codes. In particular, in the proposed scheme, two sources use digital Fountain codes to transmit their message to each other with the help of relays. Then, relays use Fountain codes and network coding to forward the source messages to both sources. To evaluate performance of the proposed protocols, we present the average total throughput over Rayleigh fading channels via Various Monte-Carlo simulations. Results show that the proposed protocol outperforms the two-way relaying transmission protocol without using network coding technique at high SNR region.

• Animal cells and systems
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• v.4 no.1
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• pp.23-30
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• 2000

Horizontal starch gel electrophoresis for 29 populations (n=543) of the wrinkled frog, Rana rugosa, from Korea and Japan was peformed to assess the degree of genic variation and genetic diversity, and to understand the biogeographic pattern of distribution and speciation. A sum of 22 presumptive loci was screened from 17 enzymes and general proteins. Four loci, Aco, Est-3, Me-2, and Pgm, demonstrated high levels of polymorphism. The degree of average genetic variation of R. rugosa was P=22.7% (9.1-40.9%), Ho=0.086 (0.048-0.165) and He=0.090 (0.042-0.168). In the south-eastern region of the Korean peninsula (Chongsong, Yongchon, Ulsan, Kyongju, Pohang, yongdok and Ulchin), a few unique alleles in the Mpi locus were detected and their biogeographic implications were considered. The degree of genetic differentiation among the Korean populations was moderate (S=0.900), whereas the degree of genetic diversity between Korean and Japanese populations was notably high (S=0.687, D=0.293). This result corresponds with the data obtained by the mitochondrial cytochrome b gene sequence (Lee et al., 1999) suggesting that the Korean and Japanese R. rugosa might have evolved a specific level of genetic differentiation since their geographic isolation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.4
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• pp.374-379
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• 2006

Central granular cell odontogenic tumor(CGCOT) is a very rare lesion that consists of densely packed granular cells with numerous scattered strands of odontogenic epithelium interspersed throughout the tissue. CGCOT was initially reported in 1962 by Cough et al as central granular cell ameloblastic fibroma. But, recently, this term is inappropriate because of histologic and chronologic differences. CGCOT is usually present as painless swellings. Radiographs show a well-demarcated radiolucent or mixed radiopaque-radiolucent lesion. The average age on presentation of CGCOT is 47.3 and women are 75% more likely to develop this lesion than men. The tumor only occur in tooth bearing areas of the jaw with 88% of cases occurring in the mandible and 12% involving the maxilla, usually in an equal distribution between the caninepremolar-molar areas. This tumor is benign, and care is effected by localized surgical excision. We report an additional case of CGCOT that occurred in the Rt. Maxillar premolar/molar region of a 32-year old man with literature review.

• Journal of Environmental Science International
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• v.21 no.3
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• pp.327-337
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• 2012

Air pollution inventories are aggregated around south-eastern part of the Korean Peninsular including Busan, Ulsan, and Changwon cities. Because densely populated cities are concentrated in this region, air pollutants emitted from one of these cities tend to be impacted on the air quality of other cities. In order to clarify the seasonal movement pattern of emitted particles, several numerical simulations using WRF/FLEXPART were carried out. Four cases were selected for each season. The Weather Research and Forecasting model (WRF) reproduced atmospheric flow fields with nested grids. The seasonal pattern of air mass of study area was determined by backward and forward trajectories. As a result, the air parcel moves from northwest to southeast due to northwesterly winds in spring and winter. Also air parcel transports from south to north in summer, and moves from west to east. Because the air mass moves differently in each season, these characteristics should be considered when performing air quality analysis.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.12
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• pp.671-678
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• 1999

In this study, it has been aimed that the accuracy of position control be increased by microstep drive to the 2 phase 8 pole HB type prototype of linear pulse motor of which winding are applied sine wave current and the vibration and noise in the lower speed region be decreased. The fixed off-time method which controls the exciting current bandwidth, was applied to the microstep current controller. When the LPM was driven 1/8 microstep its accuracy of position was 0.109[mm] (=tooth pitch 3.5[mm] ). Also, the elimination method of harmonics in the static thrust force is proposed. It was confirmed that the position error range of the prototype LPM was $\pm$0.2[mm].

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.4
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• pp.416-425
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• 2011

To analyze the physical processes of sea-breeze development over a coastal urban area, numerical simulation for seabreeze (SB) and its frontogenesis was examined based on urbanized MM5 (uMM5) with urban canopy parameterization. On 6 August 2006, SB and its front were well developed in Busan under a weak offshore flow. As a result of wind vector, ZVB (Zero Velocity Boundary), potential temperature obtained the uMM5, at 0900 LST, SB advanced below 200 m height in the coastal areas and the internal boundary grew with the urban coastal region. At noon, the height of the SB head with updraft was approximately one and a half times (~600 m) higher than its depth in central urban. Applying the frontogenesis function, the SB structure for frontogenesis and frontolysis were complicated spatially; the dynamic effects of wind (i.e. convergence and tilting term) could play an important role in the growth of SB, especially the convergence effect.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.9
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• pp.739-743
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• 2011

Ga doped ZnO (GZO)/Cu bi-layer films were deposited with RF and DC magnetron sputtering on glass substrate and then the effect of post deposition annealing temperature on the structural, optical and electrical properties of the films was investigated. The post deposition annealing process was conducted for 30 minutes in gas pressure of $1{\times}10^{-3}$ Torr and the annealing temperatures were 150 and $300^{\circ}C$. With increasing annealing temperature, GZO/Cu films showed an increment in the prefer orientation of ZnO (002) diffraction peak in the XRD pattern and the optical transmittance in a visible wave region was also increased, while the electrical sheet resistance was decreased. The GZO/Cu films annealed at $300^{\circ}C$ showed the highest optical transmittance of 70% and also showed the lowest electrical resistance of $85\;{\Omega}/{\Box}$ in this study.