• The Journal of Engineering Geology
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• v.20 no.4
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• pp.401-407
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• 2010

This study was carried out to produce the characteristics of pollutant loads caused by a cherry tree plot as a nonpoint sources(NPS) unit in agricultural areas. The relationship between rainfall and runoff didn't show a good coefficient with 0.5. Despite precipitation amount was less than 20 mm, runoff occurred with $0.5\;m^3$ because of high rainfall intensity of 8.8 mm/hr. In contrast, runoff was not occurred when precipitation amount was 47.4 mm in one case. In that case the primal effect on runoff was not precipitation amount. Correlation between load of pollutants such as BOD, COD, TN and TP and runoff' volumes showed significantly positive values which were more than r = 0.92 for all pollutants except SS(r = 0.71). SS could be a proper factor for estimating pollutant loads of BOD, COD, TN and TP because of a high correlation more than r = 0.73 between SS load and pollutant loads of BOD, COD, TN and TP. Both Organics and nutrient pollutants could be reduced if we control SS in runoff. The highest concentration of TN was detected in the event which was affected by fertilization activities directly. Therefore fertilization must be considered as a function of impact parameters on TN load in agricultural areas.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.121-128
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• 2006

The results of COD researched on August of 2004 were 6.8 ppm in North Mokpo inner Bay, 4.4 ppm in front of YongSang Bank and 4.6 ppm in front of ShinAn Beach Hotel which is over III level Marine-Environmental Standard. The other five stations sea water quality of Mokpo inner bay were reached II-III level. Concentration of total nitrogen range from 1.23 ppm to 3.56 ppm and total phosphorous was range from 0.07 ppm to 0.12 ppm which were II-III level. This results show that the Mokpo inner bay is unsuitable for aquaculture and growth of fish and for use of marine resort, it can be only available for industrial and harbour use. In results of estimated point source flow into Mokpo inner bay, the occupation ratio from YoungSang river in total inflow of TN and TP were up to 49-89 % respectively. It is indicate that in order to improve the water quality of MokPo inner bay have to control the discharge from YoungSang river first of all, then control the discharge from North Harbour domestic wastewater treatment, InAm river and NamHae domestic wastewater treatment.

• Journal of Advanced Navigation Technology
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• v.20 no.6
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• pp.595-603
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• 2016

In the Republic of Korea, the LTE-based public safety (PS-LTE) network is being built for the 700 MHz frequency band. However, the same bands are also assigned to the LTE-based high-speed railway (LTE-R) network. Therefore, it is essential to utilize the co-channel interference management schemes for the coexistence of two LTE networks in order to increase the system throughput and to reduce the user outage probability. In this paper, we focus on the downlink (DL) system for the coexistence of PS-LTE and LTE-R networks by considering non radio access network (RAN) sharing and LTE-R RAN sharing by PS-LTE users (UEs) to analyze the UE throughput. Moreover, we also utilize the cooperative communications schemes, such as coordinated multipoint (CoMP) for the coexistence of PS-LTE and LTE-R networks in order to reduce the UE outage probability. We categorize the coexistence of PS-LTE and LTE-R networks into four different scenarios, and evaluate the performance of each scenario by the important performance indexes, such as UE average throughput and UE outage probability.

• International Journal of Highway Engineering
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• v.6 no.4 s.22
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• pp.75-89
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• 2004

Long term performance of concrete pavement significantly depends on the given construction and environmental condition. It means that random cracks and extreme crack width due to inappropriate quality control at the early age might lead to decreasing the pavement service life. The temperature and moisture during the construction, cement and aggregate types, curing condition are major components to affect the quality of the concrete pavement at the early age. First of all, the high temperature differential, that is made by increasing air temperature and the heat of cement hydration, is known as the major contributor to severe cracks. In this study, tent covering was used for controlling temperature of the concrete slab. The field measurement data indicates that the effect of the tent covering is very significant to decrease possibilities of random crack occurrence and curling stress and enhance the long-term concrete strength. HIPERPAV(High PERformance PAVing software), a program predicting the strength and stress of an earty-age concrete pavement (72 hour after placement), is used for simulating the effects of tent covering. The HIPERPAVE results showed that the section with the tent covering has higher reliability than the section without the tent covering by 22.5%. In details, reliability is increased 72.5% (without the tent covering) to 95% (with the tent covering).

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.65-72
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• 2008

Mobile Collaboration is an enabling technology that makes users share information between mobile devices and various Mobile P2P platforms have been designed and implemented for it. There are, however, few research papers on application of SIP protocol to spatial data sharing on mobile devices. In this paper, SIP based real time sharing framework is proposed to compose a mobile P2P platform on which spatial data can be trans(erred. A new protocol based on WKT and WKB is defined to send and receive spatial objects with SIP MESSAGE method. Base maps such as digital maps and parcel maps can be provided by a map server that is integrated with SIP server after a new SIP session established and client agents are registered. The framework proposed based onSIP enables users to transfer spatial data such as maps and satellite images directly between mobile devices during VoIP based voice call and therefore, mobile applications can be applied in various domains such asforest management and national defense.

• Clean Technology
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• v.26 no.1
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• pp.13-21
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• 2020

Air pollutants in a subway are complexly caused by outdoor factors such as ventilating opening and indoor factors such as the movement of passengers on the subway. According to recent research results, most of the air pollutants generated in subway tunnels and stations are caused by indoor variables such as train movement. To control air pollutants such as particulate matter (PM), a prevention facility such as the electrostatic precipitator (EP) or bag filter collector was required in a subway station. In particular, the PM removed by the EP must be kept clean continuously to manage PM effectively. Therefore, a nano-bubbling washing system was developed in this study to clean a contaminated collecting plate in an EP at the main subway tunnel in Seoul. Removal efficiency compared with normal water and nano-bubbling water was likewise studied. As a result, the washing efficiency of collective PM increased in accordance with the increasing of injection pressure, with nano bubbling washing being 130.8% higher than tap water. According to increase in washing times, the maximum washing efficiency was 143.1% higher than tap water, but suitable washing times were less than 3 times. According to the results of the washing efficiency by variation of residence time, it was confirmed that the maximum residence time of nano-bubble water was maintained within 5 minutes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.381-385
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• 2010

An aging Society solitary life old mans are increasing. The nurses have to visit old mans and must confirm their disease, because they do not act well. It is very difficult to take care old man, because the number of Nurses are small. This problem is solved by collection of data about condition of old mans from long distance. Data communication with Ethernet have benefit to collection of measurement of old man's condition. The Data storage system an long distance place are storaged data and after several day data was transmitted to the DB over the Ethernet. For Miniaturization of such system the system must be OS-less Embedded Ethernet Server system. Such system manages the file management system only with H/W. The Storage device is used SD-card. SD Card is small size and operates with small power. By using 512MB sd memory card, it is possible to storage during 5~6 years, 10 byte of temperature value per second. In this paper, we make a Embedded Ethernet Server using W3100A, Atmega128 MCU and data stroage device using SD-Card. This system operates with O/S-less Embedded Ethernet Server. We talk about file System, Storage and Ethernet. We explained about MCU Atmega128, Interface between LAN LSIand W3100A, Interface between W3100A and Phyceiver RTL8201, data I/O between MCU and SD-Card and File System. We shows the experiment device and result of monitoring.

• The KIPS Transactions:PartD
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• v.13D no.6 s.109
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• pp.847-856
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• 2006

In this paper, we suggested a mobile collaboration framework for supporting mobile services among mobile devices, and designed and implemented on this environment. The suggested framework has three elements; groups of sensors and mobile devices(Fixed and Moving-typed PDAs) and a home server. We designed interfaces for interactions with each other in collaboration environment with three elements described above. The information collected by sensors can be share and exchanged by mobile devices or a home server in accordance with Push and Pull methods. This framework is based on the distributed object group framework(DOGF) we implemented before. Therefore the DOGF provides functions of object group management, storing information and security services to our mobile collaboration framework via application interfaces defined. The information collected by sensors is arranged according to user's security 'demands. And user profile information is used for checking authority of each service object. Each component for executing functions of mobile devices and a home server is implemented by TMO scheme. And we used the TMOSM for interactions between distributed components. Finally, we showed via GUI the executablity of a given healthcare application scenario on our mobile collaboration framework.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1091-1101
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• 2012

Device-to-device (D2D) communication is expected to offer local area services with low transmit power and short link distance, even not via any infrastructures. These advantages will lead to the deployment of D2D systems in a massive scale, where the order of magnitude of D2D user density is higher than that of cellular user density. Network-assisted D2D systems, where D2D resources are managed by cellular networks, are unable to support the large number of D2D devices, due to the signaling overhead for control signals. In this case, no coordination can be an answer. This paper considers uncoordinated D2D systems, which is implemented with a number of D2D devices in a large scale. By analyzing the transmission capacity of D2D systems, we found a feasibility condition under which the uncoordinated D2D communications possibly coexist within cellular networks, sharing the uplink spectrum. In addition, we provide guidelines for the operational points of massive D2D communications, giving some knowledge about proper transmit power level and link distance of uncoordinated D2D.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.2
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• pp.129-135
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• 1999

The telemetry system for the current speed and direction, the underwater ambient noise and the distribution ecology of fishes was constructed by the author and his collaborator in order to product and manage effectively in shallow sea culture and setnets fisheries, and then the experiments for the telemetry system carried out at set net fishing ground located Nungpobay in Kojedo from October 1996 to June 1997. As this results, the techniques suggested in the telemetry system gave full display its function even though far away 1.5 km from transmitting part, but with the suggested telemetry system could not be ascertained relationship between physical environment and distribution ecology of fishes.