• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1B
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• pp.9-18
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• 2006

Advances in wireless network are enabling the development of ubiquitous multimedia services. These multimedia services need efficient platforms to comply with the requirements of mobile computing. We introduce an adaptive service platform based on mobile agent and grid systems while specifying the challenges of ubiquitous multimedia services and focusing on frequent disconnections and scarce resources. We applied our platform to framework RtoA (Ready-to-Attend) which supports mobile users to access compute-intensive multimedia service, specifically, mobile education and video conferencing. RtoA includes hand-off, speaker and listener service which enable people to attend a conference or a class with satisfying quality of multimedia service. ns-2 based simulation verifies that our scheme is an efficient way to reduce energy consumption of mobile devices and to improve the response time of mobile applications.

• Korean Institute of Interior Design Journal
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• no.23
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• pp.139-147
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• 2000

The cultural identity of design is very critical in the modern society which is called the society of complex culture and multi-culture. In addition, adopting a traditional lattice-like pattern as a composition element of interior space is an effective way in the context of adding a traditional touch to the modern interior space. Meanwhile, in the process of applying Korean traditional lattices to modern interior space, some problems occurred: it has not been properly embodied; or it has been mistaken for those of China and Japan sharing similar culture with Korea. Thus, this study is designed to have precise knowledge of Korea, Chinese and Japanese traditional lattices. Besides, typical patterns of each nation's lattices are comparatively analyzed from the geometrical viewpoint, in a bid to pave the way for th modernization of traditional lattices. In particular, standards are set and proposed to identify different nations's lattices mainly focusing on grid type lattices which are often used and confusing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8B
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• pp.1251-1258
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• 2010

Major utilities have been focusing on R&D and business of AMI system which plays a vital role in SmartGrid whose concept is to optimize energy efficiency with exchanging real time information between utilities and consumers based on IT technologies in power grid. In this paper, we introduce KEPCO's AMI business plan, the AMI System architecture, designed core devices, communication networks and value added services, and also explore technical and business characteristics of KEPCO's AMI system.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.1
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• pp.11-23
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• 2014

Wireless Mesh Network(WMN) has drawn much attention due to easy deployment and good scalability. Recently, major power utilities have been focusing on R&D to apply WMN technology in Smart Grid Network. Smart Grid is an intelligent electrical power network that can maximize energy efficiency through bidirectional communication between utility providers and customers with ICT(Information Communication Technology). It is necessary to guarantee QoS of some important data in Smart Grid system such as real-time data delivery. In this paper, we suggest QoS enhancement method for WMN based Smart Grid system using IEEE 802.11s. We analyze Smart Grid Application characteristics and apply IEEE 802.11s WMN scheme for Smart Grid in domestic power communication system. Performance evaluation is progressed using NS-2 simulator implementing IEEE 802.11s. The simulation results show that the QoS enhancement scheme can guarantee stable bandwidth irrespective of traffic condition due to IEEE 802.11s reservation mechanism.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.32-40
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• 2017

The current status of Performance-Based Design (PBD) implemented in 4 wide areas (Seoul, Gyeonggi, Incheon and Busan) over the past 5 years was reviewed with regard to the number of PBD implementation and target buildings. Then, detailed status related to fire scenarios, input information for fire simulation, and grid size were analyzed with the pre-review for the PBD. As a result, the domestic PBD was mainly applied to the mixed occupancy. In the fire simulations performed on the identical fire scenario and fire space, the maximum heat release rate (HRR) varied significantly depending on the PBD designer. Various combustibles were also considered for the identical fire source, and their combustion properties also showed considerable uncertainty. In addition, the applicability of accurate input information for predictive models of heat and smoke detectors was examined. Finally, the average grid size for the fire simulation using Fire Dynamics Simulator (FDS) was analyzed, and the improvement of PBD to minimize designer dependency was proposed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.266-267
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• 2017

A numerical investigation of the stage separation behavior of two-body vehicle focusing on its flow characteristics were carried out. For this simulation, separation of a booster from vehicle was modeled by a chimera grid system and calculated by using commercial code, CFD-FASTRAN$^{TM}$. Consideration of a spring force, gravity and relative acceleration of a booster was the essential factor that simulates the realistic situation. In this study, It was validated that the booster separation time decreases with increase in flight mach number and angle of attack. In view of the results so far achieved, it was expected that the dynamics modeling and boundary condition set up applied in this study will be helpful in a estimation of a safe stage separation and event sequence of flight test.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.4
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• pp.91-98
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• 2018

A numerical investigation of stage separation behavior of a two-body vehicle focusing on its flow characteristics is carried out. For this simulation, the separation of a booster from a vehicle is modeled using a chimera grid system and calculated with commercial code, $CFD-FASTRAN^{TM}$. Consideration of spring force, gravity and relative acceleration of a booster is the essential factor of a realistic simulation. In this study, it is validated that the booster separation time decreases with an increase in flight Mach number and angle of attack. In view of results thus far achieved, it is expected that the dynamics modeling and boundary condition set-up applied in this study will be useful for estimating safe stage separation and event sequencing of flight tests.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8C
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• pp.663-669
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• 2012

To solve the energy problem and finding new growth engines, interest for the smart grid is increasing and related technologies are making great efforts to secure in the world. AMI (Advanced Metering Infrastructure) Among them is the first to be constructed and getting attention as a key component of smart grid. A fusion of various technologies in technology development and demonstration is underway on Jeju Island Smart Grid Demonstration Complex in Korea, and focusing on broadband power line communication technology infrastructure is actively underway in Korea Electric Power Corporation. AMI system using power line communication technology without building a separate communication lines are available for power supply lines, but communication is impossible in occurs because admission to the power company or the ideal infrastructure for communication is not considered. In this paper, we analyze the requirements to build AMI system using Binary CDMA and powerline communications technology, and design the basic communication protocol based on Binary CDMA, implement network management and relay feature. By doing so, ways to apply Ad-hoc Binary CDMA indigenous technology to the AMI system were derived, and could build a system to make use of Wired (PLC) and wireless (Binary CDMA) simultaneously.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.3
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• pp.245-256
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• 1999

Watershed delineation is the process of tracing surface water flow across a landscape to identify hydrologic basins. Manual and automated techniques have been developed to trace surface waters and locate watersheds on a variety of landscape. Low topographic relief landscapes, however, are particulary problematic for automated watershed delineation techniques. Therefore, this study aims at focusing the watershed delineation algorithm of low topographic relief landscape. By using topogrid, which manages enforcement drainage algorithms and incorporates topographic data into stream data, this study delineates watershed boundary in low relief landscape. Based on this research, in a low topographic relief landscape, enforcement drainage algorithms using topogrid generate better source grid to delineate watershed boundary than using only TIN. Also, comparing automated watershed delineation which incorporates contours and elevations into stream data with manual watershed delineation, we can know that the incorporation of both elevation and stream data generate more effective results.

• International Area Studies Review
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• v.22 no.1
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• pp.261-284
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• 2018

Global changeover to renewable energy is an inaugurate initiatives as one of the UN sustainable development goals. But the State alone can not achieve its goal, in particular, countries classified as bad governance. However, when the combination of innovative public-private partnerships including technology and operational innovation can be made, it can provide with rural remote villages of developing countries with more sustainable environment. In other words, we tried to show examples of success in energy supply by reducing costs and increasing marketability through various partnerships(technological innovation benefits). Base on the question, this paper examines the cases of Steama.Co, Ewang'an in Kenya, and Grameen Shakti in Bangladesh, and analyzes the developmental effects of differences in partnership types.