• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.853-871
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• 2012

The location based service is divided into GPS that uses the artificial satellite or base transceiver station in order to cover the wide area and RTLS(Real Time Location System) using the Zigbee, RFID, CSS(Chirp Spread Spectrum), UWB, Bluetooth and Wi-Fi equipment in the space(close range) limited like the building inside or park. Moreover it also repeats the technical development upon through the acceleration of the development of the wire and wireless infrastructure and determination technology, the development of the Internet, diversification of the contents, and etc. As a result, it is expected to develop around the determination technology, witch is common core technology element, contents technology, Internet and mobile communication technology, and etc. afterward. In this research, the direction we investigate was to find and analyze new technology and standardization trend of LBS in order to contribute to the related industry.

• Convergence Security Journal
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• v.5 no.3
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• pp.15-22
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• 2005

The spread of Internet and the appear of Downsizing, SI(System Integration) is chaning centralized computing to distributed computing. Also distributed computing is rapidly changing to Ubiquitous computing escape from hard wire connected network. CORBA(Common Object Request Broker Architecture) is a middleware that used for smoothness communication between application program and operation system in a different environment. However distributed computing environment is not safe from the danger, the attack like virus, worm is too intellectual and variety. In this paper, we design a new DB security model and suggest efficiency of it in Ubiquitous environment base on CSS(CORBA Security Service) that present ed from OMG(Object Management Group).

• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.55-61
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• 2006

Multimedia title needs player that depends upon operate system. This raises problems of data compatibility and resource consumption by overlapping development of player. To solve problems, we propose a method which produce multimedia title contents to internet document and then display on internet browser. Contents in multimedia title are transcoded to internet pages, having greate quality, based on CSS Layer for spatial synchronization of multimedia data. This method converts existing DB into XML for multimedia title including personal information. Therefore, XML data and resource information is playable by private multimedia player. Consequently, user can display multimedia content without player using internet browser in anytime.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5B
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• pp.370-376
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• 2012

The CSS(Chirp Spread Spectrum) technology is used for developing various WPAN(Wireless Personal Area Network) application fields in general, and it can be adapted to implement localization systems especially using SDS-TWR(Symmetric Double Sided - Two Way Ranging). But the ranging errors are occurred in many practical applications due to some interferences by some experiments. Thus, the compensation algorithm for localization is required for developing localization applications. The suggested compensation algorithm that is named KF_EDR(Kalman Filter and Equivalent Distance Rate) for localization in order to reduce the ranging errors is suggested in this paper. The KF_EDR compensation algorithm for localization is mainly composed of the AEDR(Algorithm of Equivalent Distance Rate) and the Kalman Filter. It is confirmed that the improved error ratio of the KF_EDR are 10.5% and 4.2% compared with the AEDR algorithm in lobby and stadium. From the results, it is analyzed that the KF_EDR can be widely used for some localization system in ubiquitous society.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7A
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• pp.669-681
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• 2010

In this paper, we analyze the active RFID system ISO/IEC 18000-7. In order to apply to USN, which consists active RFID tags and sensor nodes, we propose UWB-based Class 4 active RFID protocol using active RFID relay tag as relay AP. To compare the performance between the existing ISO/IEC 18000-7 system and the proposed system, we introduce sensitivity-based measurement of achieved coverage and system efficiency. Also, we analyze the performance of the proposed system and compare it with that of the existing system through MCL analysis and SLS analysis.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.49-54
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• 2016

In this paper, we propose an Arduino-based effective home security monitoring system. Proposed home security monitoring system consists of arduino which is inexpensive main processor, ultrasonic sensor and human body detection sensor to detect whether someone breaks into home. Data from ultrasonic sensor and human body detection sensor are transmitted to web server via ethernet shield connected to arduino. Web server checks whether someone breaks into home by using stored data from ultrasonic sensor and human body detection sensor. Snapshot is photographed via webcam connected by using JQuery. Photographed snapshot is stored in web server as image file. A user can monitor in web or smart device environment by using HTML5, CSS and Canvas. When examining efficiency of proposed home security monitoring system, it was found that proposed system is easier to be made than existing home security system and is cost effective by using arduino and is efficient and convenient and stable as it enables a user to handle an error in person and it uses reliable data.

• The Journal of the Convergence on Culture Technology
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• v.3 no.3
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• pp.37-42
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• 2017

We are designed to control the lipoid variation of the structure system with the stratum corneum on the skin. The skin structure is consisted of a morphology how to use the lipoid component, and the given skin structure is consisted of the mechanical shapes of the intercellular route and transcellular route, and is confirmed to control the variation state of the structure capacity. The skin impedance is appeared to result the value of measurement such as shapes of ${\lambda}-Lip-RSC$, ${\lambda}-Lip-RSL$, ${\lambda}-Lip-CSG$, ${\lambda}-Lip-CSS$ and ${\lambda}-Lip-RSB$. The condition is showed to the alteration difference value of the intercellular route and transcellular route. And, composition condition is established to separate the division parts for conversion system that is constructed with the alteration modeling. We will be possible to progress the improvement effectiveness of the continuous skin control system on the skin.

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.4
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• pp.73-86
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• 1998

The purpose of this paper is to evaluate the shear stiffness, hysteretic behavior, and ultimate behavior of HDRB(High Damping Rubber Bearing), which will be included in the seismic isolation design guideline as requirements. To do this, two 1/8 scaled HDRB are designed, fabricated, and tested to show the mechanical characteristics. The shear stiffness obtained from the proposed equation of the shear stiffness shows a good agreement with those of the experiments. For analysis of the hysteretic behavior of HDRB using the modified rate model, the parameter equations are obtained from the experiments. Using the obtained parameter equations for the modified rate model, the seismic response analyses are carried out for 1-D system. The results of analysis well follow the hysteretic behavior of HDRB obtained from the experiments. To evaluate the ultimate behavior of HDRB used in this paper, the analyses are carried out using the modified macro model, which can consider the large shear deflection. The critical shear strain(CSS) is defined to express the maximum allowable shear strain and vertical load. From the analyses, the CSS, showing the instability, decreases significantly as increased the vertical loads. The CSS is not appeared for the design vertical load in the used HDRB. In analysis using about 5 times of design vertical load, the HDRB start to show the instability transient and for about 7 times, the CSS is about 350%.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.26-36
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• 2009

Combined sewer system (CSS) has been built in the most urban areas across the nation. During dry weather conditions, CSS works fine. But during heavy rain storms, combined sewage frequently overflows into the stream. This study simulated the hydrologic cycle and pollutant loads (BOD, SS, TN and TP) in the Mokgamcheon watershed considering combined sewer overflows (CSOs). PC storm water management model (PCSWMM) was used for continuous simulation and CSOs are considered using the flow divider. Sensitivity analysis, calibration and verification for water quantity and quality are carried out. To verify CSOs, field measurements of CSOs are compared with simulated results. As a result, 41.3% of precipitation flows into the stream directly and 1.1% of water supply flows into stream as CSOs. 6.5% of BOD total loads, 12.0% of SS, 13.6% of TP, and 29.2% of TN are from CSOs. This result will be effective to the integrated watershed management for sustainability.

• Corrosion Science and Technology
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• v.20 no.6
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• pp.361-366
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• 2021

Localized corrosion behavior of Ni-based Inconel 718 alloy was investigated by electrochemical anodic polarization techniques in NACE TM 0177 A solution of 5 wt% NaCl + 0.5 wt% acetic acid at room temperature. After the solution heat treated at 1080 ℃ for 2.5 h, Inconel 718 was age-hardened at 780 ℃ for 8 h. The microstructure of the alloy surface was investigated by optical microscopic or scanning electron microscopic technique. The austenitic phase with the presence of metal carbides was observed on the surface of Inconel 718. Metal-carbides such as Nb-Mo and Ti-carbide with diameters of approximately 10 and 3 ㎛, respectively, were formed in Inconel 718. Anodic polarization results revealed that localized corrosion was observed at the interface between austenitic phase of a substrate and metal carbides. Difference in electrochemical property between a metal carbide and an austenitic substrate could provide an initiation site for localized corrosion of Inconel 718 surface.