• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.6
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• pp.116-126
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• 2013

Weather factor to affect driver's driving environment are due to changes in weather conditions is caused rainfall, snowfall, fog etc and the reducing of road capacity and because deteriorating weather could be affect the headway and vehicle speed and the decrease in lane caused by an accident occurs that was analyzed that bad weather occur congestion greater than on the clear day. Bad weather to reduce of the driver's visibility was analysed the sensitive to changes in travel speed and traffic accident to appears high characteristics according to weather conditions on the expressway(higher speed) than general road. As a result, visibility have been determined to be important factor in changes of the highway traffic flow characteristics. Therefore, in this study, we selected traffic volume and travle speed that have a major impact on high-speed expressway basic segments as importance effect factor and we selected to subject of analysis among the Metropolitan Expressway that it could be obtained certain level of traffic volume data and we studied the changing of expressway traffic flow due to change visibility after the collecting of meteorological and traffic data. In order to perform this study, data collection and analysis methods were established through the existing literature and we had selected level of visibility of the expressway and we had performed the statistical verification. Finally, we had calculated the rate of change of expressway traffic flow characteristics due to visibility and we had come up with a way to apply at capacity and service level analysis.

• Korean Business Review
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• v.12
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• pp.255-274
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• 1999

Electronic Commerce (EC) is a relatively new and has been attracting a considerable amount of attention. Even though it is still in an introductory stage, growth rates are impressively high and its economic importance will continue to grow. Electronic Commerce is born to be global because its connectivity using the Internet is universal. As Electronic Commerce accelerates the globalization, it will also increase both the interdependence of national economies in different countries and the need for international cooperation and coordination. Electronic Commerce is really a global challenge that requires global solutions. For this reason, Electronic Commerce becomes an important agenda in major international cooperative organizations including APEC, OECD, and G7 (G8). However, current international discussions on Global Electronic Commerce are initiated mostly by the United States and European Union (EU). The objective of this paper is to raise awareness creation activities in which the international cooperation is needed for promoting the global electronic marketplace in Asia. For this purpose, this paper reviews the approaches of U.S. and European countries (or European Union), and suggests an development framework on the basis of the reviews. The framework is used to analyze current issues around Electronic Commerce, and identify some fields which require coherent work among researchers in different countries.

• Journal of Broadcast Engineering
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• v.19 no.6
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• pp.767-788
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• 2014

The worldwide transition from analog to digital broadcasting has now been completed and the need to study next generation standards for Ultra High Definition TV (UHDTV) broadcasting, and broadcasting & communication convergence systems is rapidly growing. In particular, high resolution mobile broadcasting services are needed to satisfy recent consumers. Therefore, the development of highly efficient convergence broadcasting systems that provide fixed/mobile broadcasting through a single channel is needed. In this paper, a service scenario and requirements for providing 4K UHD & HD convergence broadcasting services through a terrestrial single channel are analyzed by employing the latest transmission and A/V codec technologies. Optimized transmission parameters for 6 MHz & 8 MHz terrestrial bandwidths are drawn, and receiving performances are measured under Additive White Gaussian Noise (AWGN) and time-varying multipath channels. From the results, in a 6 MHz bandwidth, the reliable receiving of HD layer data can be achieved when the receiver velocity is maximum 140 Km/h and is not achieved when the velocity is over 140 Km/h due to the limit of bandwidth. When the bandwidth is extended to 8 MHz, the reliable receiving of both 4K UHD and HD layer data is achieved under a very fast fading multipath channel.

• Journal of Wetlands Research
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• v.15 no.2
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• pp.251-264
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• 2013

There are some factors affecting the shorebirds in selecting a coastal inland roost site where they have to stay during the high tide when the entire intertidal zone is covered with water. We investigated eight species (Eastern Curlews Numenius madagascariensis, Green Shanks Tringa nebularia, Bar-tailed Godwits Limosa lapponica, Grey Plovers Pluvialis squatarola, Dunlins Calidris alpine, Whimbrels Numenius phaeopus, Eurasian Curlews Numenius arquata and Terek Sandpipers Xenus cinereus) to identify the spatial and temporal variability in coastal inland roost use in the area and the factors influencing the use. We considered the area and length of the standing water in the roost site, temperature, wind speed, the time of migration and the intensity of disturbance. As a result, number of individuals and type of species using the roost site varied across spatial and temporal scales. And the factors affecting the roost use was species-specific. The roost site of the study area was a closed shrimp farm however, it has been converted to a Salicornia herbacea, a salt marsh plant, farm recently. In a situation where coastal inland roost site is needed, we hereby describe a resolution for the juxtaposition of shorebirds and farming.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.3
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• pp.200-207
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• 2003

'||'||'||'&'||'||'||'quot;Overheating index'||'||'||'&'||'||'||'quot;, the normalized difference in incident solar energy between a target surface and a level surface, is helpful in estimating the spatial variation in daily maximum temperature at the landscape scale. It can be computed as the ratio of the 4-hour cumulative solar irradiance surplus or deficit from that over a level surface to the maximum possible deviation (15 MJ $m^{-2}$ ) during the midafternoon. Ecosystem models may, for simplicity, use an empirical proxy (exposure index) variable combining slope and aspect in place of the overheating index to account for the variation of midafternoon solar irradiance. A comparative study with real-world landscape data was carried out to evaluate the performance of exposure index in replacing the overheating index. Overheating indices for summer solstice, fall equinox and winter solstice were calculated at 573,650 grid cells constituting the land surface of Donggye-Myun, Sunchang County in Korea, based on a 10-m DEM. Exposure index was also calculated for the same area and fitted for the variation of overheating index to derive a 2$^{nd}$ -order linear regression equation. The coefficient of determination ($R^2$) was 0.50 on summer solstice, 0.56 on fall equinox, and 0.44 on winter solstice, respectively. These are much lower than the theoretically calculated $R^2$ values ranging from 0.7 in summer to 0.9 in autumn. According to our study, exposure index failed to accurately predict the cumulative solar irradiance over a complex terrain, hindering its application to daily maximum temperature estimation. We suggest direct calculation of the overheating index in preference to using the exposure index.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.12
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• pp.1292-1299
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• 2014

Weather radar systems can provide weather information of the ground, sea, and air in extensive spatial coverage in near real time. However, it becomes problematic when ground clutter signal exists around precipitation because strong signals of ground can cause a false precipitation report. A large percentage of land coverage of Korea consists of mountainous regions where ground clutter needs to be mitigated for more accurate prediction. Thus, it is considered necessary to introduce a new suitable ground clutter removal technique specifically adequate for Korea. In this paper, the C-Map(Clutter Map) method using raw radar signals is proposed for removing ground clutter using a terrain-adaptive clutter map. A clutter map is generated using raw radar signals(I/Q) of clear days, then it is subtracted from received radar signals in frequency domain. The proposed method is applied to the radar data acquired from Sobaeksan rain radar and the result shows that the clutter rejection ratio is about 91.17 %.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.3
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• pp.228-233
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• 1989

Successive changes of transpiration by the tobacco plant during the growing season with pot trial treated with 30cm and 100cm ground water tables were compared with change of soil moisture content in rhizospere of field under natural rainfall conditions. Transpiration from the 41st to the 60th day after transplanting was the highest showing about 50% of total transpiration of whole cultivation period. As the result, soil moisture condition in rhizospere of field was kept insufficiently during the above period. Transpiration by the plant was so remarkably affected by the meteorological environment that the transpiration on rain-cloudy day was one third of that on clear day at middle stage of the growth. Maximum transpiration in a clear day was obtained from 14:00 to 16:00 at the 58th day after transplanting.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.135-136
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• 2011

It is very crucial that small and medium-sized enterprises, called SMEs, should play a pivotal role in creating jobs and contributing to export. Day by day under the influence of the increment globalization of the world market and the rapid changes of business environment, our country has been heavily dependent on export to the foreign countries. Therefore, both enterprises' Marketing Mix such as Product, Price, Place and Promotion and global competitiveness are essential elements to raise the volume of export. The purpose of this research is to find out the relationships between Marketing Mix and Marketing Performance. The considerable number of 338 domestic export SMEs was surveyed to verify the hypothesis and research model through a covariance structure analysis via AMOS 18.0, accompanied by the confirmatory factor analysis to prove suggested potential variables. After the strenuous empirical analysis, the relationship between marketing mix elements and marketing performance, the place and promotion element of 4Ps' Mix proved to have a postive impact on marketing performance. This research focused on Marketing Mix as major elements in marketing performance. Theoretical and practical implications are generated to help both enterprises and policy-makers that cover comprehensive government policies for SMEs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.192-203
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• 2016

The purpose of this study is to investigate the effects of task conflict on job attitudes (organizational commitment & job satisfaction), focusing on the mediating effects of supervisory communication & co-worker communication. Recently, the importance of communication as a research topic has been increasing. According to prior research, communication satisfaction has a positive effect on job performance. However, studies which take into account the different types of communication are lacking. Therefore, this study considered two types of communication (supervisory communication and coworker communication). A research model and hypotheses were developed in order to examine the theoretical research issues and questions. The sample consisted of 280 survey data drawn from employees in firms located in Korea. The data was analyzed by the statistical packages, SPSS 21.0 & AMOS 21.0 for Windows. The findings of the analysis are as follows. Firstly, it was found that task conflict had a negative (-) effect on organizational commitment & job satisfaction. Therefore, H1a & H1b are supported. Secondly, it was found that task conflict had a negative (-) effect on supervisory communication. Therefore, H2a is supported. However, it did not have a significant effect on co-worker communication. Hence, H2b is not supported. Thirdly, as regards the mediating effect of supervisory communication, it was found that supervisory communication mediated the effect of task conflict on job attitudes (organizational commitment & job satisfaction). Therefore, H3a & H3b are supported. Finally, the mediating effect of co-worker communication was not significant. Therefore, none of the sub-hypotheses of H4 are supported. Based on these findings, this study suggested directions for future research.

• Journal of the Korean Wood Science and Technology
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• v.14 no.2
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• pp.43-49
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• 1986

In the light of real situation of Korean timber resources, it is no wonder that Korean economy depends on a lot of imported timber, however, we only need to draw attention how have they kept the balance of payment in the field of forest products trade for the last few decades, until the second oil crisis in 1979. Afterwards, the gap between imports and exports of forest products in terms of value has been widened so far, on account of various reasons inside and outside. However, according to national economic policy to drive more active exportation, new policy and strategy to expend world market of forest products urgently expectable in order to shorten the gap between imports and exports of forest products in the future. On the other hand, the current timber importation policy should be reconsidered, not only to support optimum domestic timber price level so as to compensate timber producers' cost but also to make suitable economic environment to induce new investments in the field of private forestry sector.