• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.2
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• pp.13-20
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• 2009

Recently there is growing interest in LBS requiring real-time services and the spatial main memory DBMS for efficient Telematics services. In order to optimize existing disk-based spatial indexes of the spatial main memory DBMS in the main memory, spatial index structures have been proposed, which minimize failures in cache access by reducing the entry size. However, because the reduction of entry size requires compression based on the MBR of the parent node or the removal of redundant MBR, the cost of MBR reconstruction increases in index update and the efficiency of search is lowered in index search. Thus, to reduce the cost of MBR reconstruction, this paper proposed the RSMB (relative-sized MBR)compression technique, which applies the base point of compression differently in case of broad distribution and narrow distribution. In case of broad distribution, compression is made based on the left-bottom point of the extended MBR of the parent node, and in case of narrow distribution, the whole MBR is divided into cells of the same size and compression is made based on the left-bottom point of each cell. In addition, MBR was compressed using a relative coordinate and size to reduce the cost of search in index search. Lastly, we evaluated the performance of the proposed RSMBR compression technique using real data, and proved its superiority.

• Journal of Korea Spatial Information System Society
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• v.9 no.2
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• pp.13-23
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• 2007

Recently there is growing Interest in LBS(Location Based Service) requiring real-time services and the spatial main memory DBMS for efficient Telematics services. In order to optimize existing disk-based multi-dimensional Indexes of the spatial main memory DBMS in the main memory, multi-dimensional index structures have been proposed, which minimize failures in cache access by reducing the entry size. However, because the reduction of entry size requires compression based on the MBR of the parent node or the removal of redundant MBR, the cost of MBR reconstruction increases in index update and the efficiency of search is lowered in index search. Thus, to reduce the cost of MBR reconstruction, this paper proposed the RSMBR(Relative-Sized MBR) compression technique, which applies the base point of compression differently in case of broad distribution and narrow distribution. In case of broad distribution, compression is made based on the left-bottom point of the extended MBR of the parent node, and in case of narrow distribution, the whole MBR is divided into cells of the same size and compression is made based on the left-bottom point of each cell. In addition, MBR was compressed using a relative coordinate and size to reduce the cost of search in index search. Lastly, we evaluated the performance of the proposed RSMBR compression technique using real data, and proved its superiority.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.2
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• pp.219-230
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• 2023

Cities are continued to be highly advanced and metropolitanized. Lands adjacent to road make entry/exit connection increase along with construction of facilities for various purposes. However, in the absence of specific installation standards of entry and exit connection, inappropriate access location, types of access, and operation methods are deteriorating the level of traffic services at existing roads and intersections. Therefore, in order to minimize the traffic impact from entrances connected to minor arterial roads and colletor roads, first, this study re-established the waiting length in the intersection of upstream and downstream and length required for changing lanes and between entrance/exit and connection, considering the road and traffic environment in contact with the entrance. Second, it is suggested that the operation method depending on the connection type and whether to install left turn lane and acceleration and deceleration lane can be determined quantitatively by relation with the service level of nearby intersection after calculating the threshold amount of business site through negative social cost, which is the difference between the installation cost of the left turn lane and the acceleration and deceleration lane according to the type of access to the entrance and exit.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.5
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• pp.422-428
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• 2013

Recently, many unmanned aerial vehicle (UAV) studies have focused on small UAVs, because they are cost effective and suitable in dangerous indoor environments where human entry is limited. Map building through distance measurement is a key technology for the autonomous flight of small UAVs. In many researches for unmanned systems, distance could be measured by using laser range finders or stereo vision sensors. Even though a laser range finder provides accurate distance measurements, it has a disadvantage of high cost. Calculating the distance using a stereo vision sensor is straightforward. However, the sensor is large and heavy, which is not suitable for small UAVs with limited payload. This paper suggests a low-cost distance measurement system using a laser pointer and a monocular vision sensor. A method to measure distance using the suggested system is explained and some experiments on map building are conducted with these distance measurements. The experimental results are compared to the actual data and the reliability of the suggested system is verified.

• Journal of Multimedia Information System
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• v.3 no.3
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• pp.63-68
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• 2016

Environmental downtime produces a significant cost to organizations and makes them unable to do business because what happens in the data center affects everyone. In addition, the amount of electrical energy consumed by data centers increases with the amount of computing power installed. Installation of physical Information Technology and facilities related to environmental concerns, such as monitoring temperature, humidity, power, flood, smoke, air flow, and room entry, is the most proactive way to reduce the unnecessary costs of expensive hardware replacement or unplanned downtime and decrease energy consumed by servers. In this paper, we present remote system for monitoring datacenter implementing using open-source hardware platforms; Arduino, Raspberry Pi, and the Gobetwino. The sensed data displayed through Arduino are transferred using Gobetwino to the nearest host server such as temperature, humidity and distance every time an object hitting another object or a person coming in entrance. The raspberry Pi records the sensed data at the remote location. The objective of collecting temperature and humidity data allows monitoring of the server's health and getting alerts if things start to go wrong. When the temperature hits $50^{\circ}C$, the supervisor at remote headquarters would get a SMS, and then they would take appropriate actions to reduce electrical costs and preserve functionality of servers in data centers.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.121-126
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• 2010

Regarding HEMP has been studied as few thousand of paper by major nuclear bomb holding countries with USA for the self protection against nuclear bomb attract. Major HEMP protection facilities are consist of the shielding, filtering, grounding and high voltage protection circuits. Shielding room construction required a highest cost among the key protective facilities. Most of a theoretical formulas listed on the paper and related books has a little correlations in the certain frequency band between the theoretical formulas and field measuring results. For the reasons we proposed the advanced new theoretical formulas and developed the computer simulation S/W as enough as apply to the cost effective shielding room design for HEMP considering the various structural constants.

• Current Optics and Photonics
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• v.1 no.2
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• pp.90-94
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• 2017

Visible light identification (VLID) is a user identification system for a door lock application using smartphone that adopts visible light communication (VLC) technology with the objective of high security, small form factor, and cost effectiveness. The user is verified by the identification application program of a smartphone via fingerprint recognition or password entry. If the authentication succeeds, the corresponding encoded visible light signals are transmitted by a light emitting diode (LED) camera flash. Then, only a small size and low cost photodiode as an outdoor interface converts the light signal to the digital data along with a comparator, and runs the authentication process, and releases the lock. VLID can utilize powerful state-of-the-art hardware and software of smartphones. Furthermore, the door lock system is allowed to be easily upgraded with advanced technologies without its modification and replacement. It can be upgraded by just update the software of smartphone application or replacing the smartphone with the latest one. Additionally, wireless connection between a smartphone and a smart home hub is established automatically via Bluetooth for updating the password and controlling the home devices. In this paper, we demonstrate a prototype VLID door lock system that is built up with LEGO blocks, a photodiode, a comparator circuit, Bluetooth module, and FPGA board.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.197-201
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• 2001

Output and cost efficiency in the production of hot-rolled strip depend to a large content on the uniformity of geometric and mechanical properties over the length and width of the rolled end product. To ensure the homogeneous temperatures required for this during the rolling process a system to measure and evaluate the transverse temperature profile was developed and implemented in production. The systems used consist of temperature scanners and computers for measurement and data evaluation. The systems have been installed in Kwangyang hot strip mills, in the cases at the exit of the finishing train and at the entry of the coiler. They are used in production to determine the effect of the finishing train and the cooling zone on the technological properties of the hot rolled strip.

• Journal of Information Technology Applications and Management
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• v.13 no.1
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• pp.95-116
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• 2006

Many SMEs have adopted ASP models which have brought various benefits to SMEs such as decreasing the total cost, using new IT technology, enhancing the maintenance, and implementing the information systems rapidly. Ministry of Information and Communication had implemented the ASP diffusion project for the ASP venders and SMEs between 2001 and 2003. As results of this project, various industries adopted the ASP applications of which the performance was enhanced, and then the competitiveness of the ASP vendors in Korea was increased. The purpose of this study is to make a strategy of the penetration into China market for ASP services which have competitive advantages. This study uses various research methods such as questionnaire survey, visiting SMEs in china and making interviews. This study shows the current status of Chines ASP market, the several cases of using ASP services, and questionnaire analyses(service recognition, service requirement and factors and infrastructure, business environment and supporting organizations etc) of ASP demand. And finally this study proposes several strategic considerations in entering China market and suggests several support policies for supporting Korean ASPs.

• Journal of information and communication convergence engineering
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• v.1 no.1
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• pp.48-52
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• 2003

A cost efficient IPSec Accelerator board utilizing a crypto chip and an entry-level Linux PC for the high performance VPN is presented in this paper. The IPIP (IP-over-IP tunneling) processing, encryption & decryption processing, HASH processing, and the integrity test functions of IPSec are processed in the IPSec Accelerator board. The proposed IPSec Accelerator has demonstrated successful execution of the required functions of the IPSec packet processing and verified its performance by processing the IPSec packets at the rate of over 1 Gbps.