• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.2
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• pp.97-104
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• 2011

This paper deals with the quick and precise disaster prevention automation system (DPAS) based on information communication technology (IT) that detects fire and disasters in the building automatically and quickly and then activates the facilities to extinguish fire and disasters, monitoring such situation in a real time through wire-wireless communication network. The proposed DPAS is applied a programmable logic controller (PLC) of one-chip type which is smallsize and lightweight and also has highly sensitive-precise reliabilities. The one-chip type PLC analyzes detected signals from sensors in a case of fire and disasters, then activates fire extinguishing facilities for rapid suppression. The detected data is also transferred to a remote situation room through wire-wireless network of RS232c and bluetooth communication. The transferred data sounds an emergency alarm signal, and operates a monitoring program. The proposed DPAS based on IT will minimize the life and wealth loss from rapid measures while prevents fire and disasters.

• Journal of Korea Multimedia Society
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• v.7 no.3
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• pp.438-449
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• 2004

More and more users are using the query e-mail according to the increment of use of internet. The operator of internet site desires the users to check the FAQ and Q＆A contents first before sending the query e-mail to the operator However the users try to get the solution for a problem easily by simply sending a query e-mail. Therefore the increment of query e-mail is inevitable, and the site operator is suffering from too heavy loads and spending too much time and cost to reply the query e-mail. In this paper, we are proposing an efficient method of classifying the query e-mail of users automatically by using a neural network. To verify the reasonability of our work, the query e-mails of KORNET are used as the test data, which is actually gathered in KT. A total of 210 learning data and 280 test data were used to test the performance of the proposed approach. From the experiments we got the encouraging result from the view point of application in real life. The proposed approach satisfied the request of users who wanted rapid response for their query e-mail.

• Journal of Advanced Navigation Technology
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• v.13 no.4
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• pp.551-558
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• 2009

Most of clustering schemes focusing on the energy efficiency have only a cluster head in each cluster, thus the energy consumption of cluster head in a cluster can rapidly increase. To reduce the energy consumption, recently, the dual-layered clustering which is separated a cluster ranges into two parts, i.e., data aggregation layer and data transmission layer, based on a sensor equipped with geographical positioning system (GPS), was proposed. However, the logical regions existing within the dual-layered clustering range can not distinguish efficiently. This scheme leads to many messages collision and transmission delay among member nodes. In this paper, to solve these problems, we propose a separated dual-layered routing scheme using the position information and the cluster radius. Proposed scheme clearly distinguish the dual-layered clustering range and gets the balanced number of member nodes in each cluster. Therefore, the proposed routing scheme could prolong the overall network life time about 10% compared to the previous two layered clustering scheme and LEACH.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12B
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• pp.2298-2319
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• 1999

In this paper, we propose a new moving mobile base station (MMBS) scheme for very low power and micro-size RMIMS (radio-interfaced micro information monitoring system) terminals. RMIMS terminals can be used in various application service areas such as pollution monitoring, environment surveillance, traffic monitoring, emergency monitoring (e.g., building, bridge, railroad breakdown), security monitoring (e.g., theft, alarm) and military application. For these applications based on wireless transmission technologies, sensor type RMIMS terminals must satisfy low cost and low power design (e.g., solar power, life limited battery) requirement. In RMIMS terminal design, this low power requirement limits transmission range of uplink or reverse link and means small cell size. Also these applications using RMIMS terminals may have a little bit non real-time traffic characteristic and low scattering density in service area.

• International Commerce and Information Review
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• v.4 no.2
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• pp.77-96
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• 2002

Through the new round DDA(Doha Development Agenda) negotiations which started in Doha/Qatar conference in November, 2001, service industries have been included in the category of international trades. An electronic commerce cannot be exceptional in this field. The 21st century is largely recognized as the era of globalization, knowledge, and information. To make effective and competitive strategy in this century, it is essentially required to organize Network. OPEN, and FU-PLEX. That is why our government also has been promoting this field since years before, now 10,000,000 people in Korea have joined superhighway internet networks. Korea became the top internet-developed country in the world. As a side-effect of this internet spread into our life, however, there is serious problem we are now faced against. That is the outflow of private information through electronic commerce and other cyber transactions. It has caused many social problems to be rapidly on the rise these days. We are now desperately required to struggle continuously to make a solution for that. Taking the precedent case of Germany and United States which are currently recognized as high-leveled country in protection of private information, we have to come up with legal and technical measures and at the same time, to escalate the social consciousness about private information protection.

• The Journal of the Korea Contents Association
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• v.10 no.11
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• pp.58-67
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• 2010

Data-centric storage schemes(DCS) are one of representative researches that efficiently store and manage sensor readings in sensor nodes in the sensor networks. In DCS, a sensor sends the sensed data to a specific node in order to store them. However, it has a problem that sensor nodes consume a lot of energy for transmitting their readings to remote sensor node. In this paper, we propose a novel sensor data compression algorithm to reduce communication costs for DCS. The proposed algorithm establishes a safe region and transmits the sensed data only when current measurement is out of the safe region, As a result, the proposed algorithm extends network life time and reduces data transmission. It is shown through performance evaluation that our proposed algorithm reduces energy consumption by about 60% over the conventional algorithm.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.271-276
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• 2014

The life-time and performance of a wireless sensor network is closely related to energy-efficiency of sensor nodes. In this paper, to increase energy-efficiency, each sensor node operates in one of three operational modes which are normal, power-saving, and inactive. In normal mode sensor nodes sense and transmit data with normal period, whereas sensor nodes in power-saving mode have three-times longer period. In inactive mode, sensor nodes do not sense and transmit any data, which makes the energy consumption to be minimized. Plus, the proposed algorithm can avoid unnecessary energy consumption by preventing transmitting duplicate sensed data. We implemented and simulated the proposed algorithm using Tiny OS based ZigbeX platfom and NS-2, respectively. Performance evaluation results show that the proposed algorithm can prolong sensor networks' lifespan by efficiently reducing energy consumption and its standard deviation of all sensor nodes.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.4
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• pp.513-525
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• 2019

In Seoul, the subway system has been in use since 1974 and is the most frequently used travel mode accounting for approximately 40% of passenger journeys in 2015. As such the subway system is widely adopted by people and therefore, can have great impacts on their everyday life. However, it is easily noted that transit resources are not distributed spatially uniform, in other words, not all parts of the city gain the same benefits from their networks. This study aims to examine the inequity of spatial distribution of subway networks based on accessibility. Accessibility of subway networks are calculated based on the time-distance between stations and then equity is measured using the Gini index. Resulted map of subway accessibility shows that the benefits are not evenly distributed in Seoul with a pattern of highly accessible core - less accessible periphery areas. Also the subway accessibility network has fairer distribution against the employees' distribution rather than the distribution of general population or possibly transit dependent groups.

• Korean Institute of Interior Design Journal
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• v.24 no.2
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• pp.58-66
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• 2015

This study was conducted to determine a 'platform' as a mean of interactions between users in contemporary spatial design and network(web) and to verify the similarity between the platform and space of Rem Koolhaas, one of the leading contemporary architects of our time. A platform, referring to tangible or intangible structures designed for common use in a variety of ways, is activated by the networking effect of participants. Aided by the recent development of the IT industry encompassing computers and smart phones, the concept of platforms is extending to all areas of modern life, in general. In this study, the similarity between architectural space and platforms after reviewing the computer-related platforms, ecological features that refer to virtuous circulation, and various cases applied with platform thinking. Through this process, the platform feature of architectural platforms is defined as the 'open spatial system combined with control and freedom that acts more than one function and facilitates direct/indirect exchanges between users regardless of its type or size'. Establishing the criteria for spatial analysis based on this definition, analysis was conducted on interior design projects that were planned and conducted by Rem Koolhaas after 2000. As a result of this analysis, it was learned that Rem Koolhaas designs space using dual space structures where the extension and mixture of the user group, mixture of various functions defined by users, loose control that induces voluntary participation, community reinforcement, and inducement of accidental events, and opening and closing coexist. In addition, this design approach was found to be a design strategy similar to the concept of platforms that began to be developed in the IT field.

• The KIPS Transactions:PartC
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• v.11C no.7 s.96
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• pp.951-958
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• 2004

Nowadays NGN is developed for supporting the e-Commerce, Internet trading, e-Government, e-mail, virtual-life and multimedia. Internet gives us the benefit of remote access to the information but causes the attacks that can break server and modify information. Since 2000 Nimda, Code Red Virus and DSoS attacks are spreaded in Internet. This attack programs make tremendous traffic packets on the Internet. In this paper, we designed and developed the Bandwidth Controller in the gateway systems against the bandwidth saturation attacks. This Bandwidth con-troller is implemented in hardware chipset(FPGA) Virtex II Pro which is produced by Xilinx and acts as a policing function. We reference the TBF(Token Bucket Filter) in Linux Kernel 2.4 and implemented this function in HDL(Hardware Description Language) Verilog. This HDL code is synthesized in hardware chipset and performs the gigabit traffic in real time. This policing function can throttle the traffic at the rate of band width controlling policy in bps speed.