• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.575-584
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• 2003

Due to hardware resource limit and system incompatibility of the mobile device, and low bandwidth of wireless communication, there are a few difficulties in introducing the digital contract system based on wired communication to M-Commerce. To get over the difficulties, this paper defines a digital contract based upon XML and then addresses the design and implementation of M-XContract, a digital contract system for the mobile environment. M-XContract system has been constructed with the digital contract server, M-ESign module which contracts with the customer on the PDA and transfers the contract digitally signed to the server, M-EDecoder module which shows the contract to the customer from the server, and X-Auth which is a contract authoring tool. To evaluate the run-time performance of the M-XContract, we measured the digital signature generation time and transfer time to the server. The evaluation results show that the M-Xcontract is an efficient model for the mobile contract system.

• Journal of the Korea Convergence Society
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• v.7 no.6
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• pp.29-34
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• 2016

Nowadays, real-time devices that provide health care for a companion animal is being developed by IoT technology and its demand such as smart puppy tag is increasing. However, it is difficult for IoT devices of companion animals to process complex nature due to miniaturized hardware and constructive nature. There is a clear limit to custom advanced features like health care implementation. This paper designs an integrated platform with statistical analysis which makes it possible to customized services such as feed production, pharmaceutical production, and health care for each companion animal. Middleware that collects sensor information, customer's spending pattern and information from Social Network Service is also designed by making use of IoT devices which companion animals wear. Furthermore, the paper designed data analyzer which analyzes and refines data from collected information that can be applied to personalized services.

• Journal of the Korean Institute of Telematics and Electronics
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• v.17 no.4
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• pp.11-17
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• 1980

This paper describes realization of digital filter using $\mu$p controler and discusses measured characteristics of this filter, The idea of P. L. implementation[1] is used in realization, and in this system we utilize a DMA and arithmatic control program of $\mu$p. In this way, we can get more flexible capability than the basic PL method, and higher speed than a filter using general purpose $\mu$p in hardware, Furthermore, we get a 15 KHz sampling frequency(fs) as speed limit in real time processing, and know that this limitation is restricted by execution time (58$\mu$ sec) of DMA control statement. As for filter charateristics, maximum stop band frequencies (fsp) are 1665 Hz, 1445 Hz in Butterworth and Tchebichef approximation, respectively, when fs = 14 KHz. Measured errors between the design specification and the actual result are 0.2dB, 0.1 dB in pass band (when cufoff frequency is 500Hz),-1.1dB (when fsp is 1000Hz), 0.4dB(when fsp is 750 Hz) in stop band frequency of Butterworth and Tchebichef, respectively.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.95-101
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• 2009

As RFID technology has been developed rapidly, its technical potential has it be widely used in many industrial fields. Particularly, in the physical distribution industry, the introduction of RFID has enormously contributed to effectively monitoring locations and information of products in real-time. Also, a significant decline in tag prices and RFID related technical competitiveness enabled each tag to be managed much more minutely by attaching it to an item, not a pallet nor a container. However, if a very large volume of tag data are continuously flowed into a RFID middleware with limited hardware resources, its entire data processing time may become considerably longer. Therefore, specific technologies are in great demand to handle and further to reduce the load of the middleware. In this paper, we proposed a mobile agent-based software module to efficiently reduce the load of the middleware by pre-processing a lot of tag data while items are in transit. Simulation results show that using the proposed software module considerably enhances the speed of processing tag data than otherwise. This behavior increases the tag recognition rate in a certain time limit and improves reliability of RFID middlewares.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.654-659
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• 2009

As web based software has developed recently, service via web has increased gradually. For this, many research organizations and reports call web is the platform of software. While web based technologies have developed, middleware of WSN and its application service has been developed from desktop based operation system. So WSN's technology reached uppermost limit of desktop application. There's difficulty in integrating, distributing and maintaining & repairing for WSN due to a tightly-coupled structure which's related closely to the hardware of sensor nod. Unlike this, web has a loosely-coupled structure and an opened system, so web service or Rich internet application (RIA) is helpful to solve the above limits. Especially, RIA is web application but can be the platform of WSN' application because it gives us various methods to communicate with user interface similar to desktop application. In this study, I suggest Message System for WSN Using RIA, expanding WSN's interconnectedness and accessibility to internet.

• Journal of Advanced Navigation Technology
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• v.18 no.5
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• pp.476-482
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• 2014

Recently, with the growth of various sensor applications, the need of wireless communication systems which can support variable data rate is increasing. IEEE 802.15.4 LR-WPAN system using 2.45 GHz frequency band is very popular for the sensor applications. However, since LR-WPAN only supports the data rate of 250 kbps, it has a limit to be applied to various sensor networks. Therefore, we define the preamble structure which can support the data rates of 31.25 kbps, 62.5 kbps, 125 kbps, and present the low-complexity hardware architecture for time synchronizer based on double-correlation algorithm which can resist the CFO (carrier frequency offset). Implementation results show that the proposed time synchronizer include the logic slice of 18.36 K and four DSP48s, which are reduced at the rate of 79.1% and 99.4%, respectively, compared with existing architecture.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.198-207
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• 2009

Recently, it was possible to represent the realistic clothes in the cloth simulation along with growth of 3D computer animation such as visual contents. In addition, because of the development of H/W(Hardware) and S/W(Software), the accessibility and participation are growing. However, in order to make the image of high quality of 3D animation, the optimized production pipeline was need. In this paper, in order to overcome the limitation of exiting 3D computer animation production pipeline, we propose the optimized production pipeline of the cloth simulation. Our production pipeline makes the optimization arrangement in consideration of the mobility in order to supplement the related structure limit toward each part of the existing pipeline. Moreover, by utilizing the dummy cloth the association nature with the animation part is solved and a performance is improved. The proposal pipeline actually introduced to the animation production. And then we can improve the performance production time and production manpower consumption. Consequently, our pipeline is guaranteed an optimized work by emphasizing a connection in the direct image production.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1184-1192
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• 2008

There have been a large number of trials of the experimental education in engineering using virtual laboratories implemented in virtual space, namely on the Web. Although virtual education is regarded as an effective educational means that overcomes the limit of time and space and bring high teaming effects, the problem of lack of reality must be solved. The present study proposed and implemented a real-time remote laboratory as a solution for the problem of lack of reality in virtual education. The remote laboratory provides functions with which learners can perform experiments by remote-controlling circuits and equipment related to experiments and practices on the Web and gets data and image information, so through it learners can make realistic experiments at any time and in any place. The remote laboratory module based on Internet open sources such as JAVA Web start technology, FTP technology and Telnet technology in server-client environment can be implemented at low cost, and is effectively applicable to engineering experiment education in various areas related to real-time hardware control.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.136-141
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• 2008

The rapid development of the information technology has passed over the implementation of the virtual reality. It is realizing information services that are form of the globalization, based on the Internet. In addition, the effort to apply IT to public administration for public services has been made. The remarkable development of computer hardware has overcome the limit of the information distribution and emerged for practical use in various fields such as public institution, underground facilities management, tourism industry development etc. However, the practical use of Virtual Reality with Three-Dimensional GIS on disaster management by Korea National Emergency Management Agency is very much low. Therefore, this studies focus on how to use 3-Dimensional GIS for the purpose of fire disaster prevention. The studies also discussed, through understanding of the limitations of 2-Dimensional GIS, the establishment of basis for fire prevention technology development and its utilization among those ubiquitous city paradigms, which have become so much issues these days.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.5
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• pp.438-444
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• 2016

In this paper, A real-time channel module which can apply the wireless propagation channel was developed using USRP and Lab-VIEW. When the proposed channel module is used in conjunction with the implemented HW(hardware) simulators for cognitive radio and frequency interference analysis and so on, it can increase the reliability about wireless propagation environments. In addition, the proposed module overcomes the limit of existing HW simulator that data transfer rate is limitative in communication system through the design of the inner parts. Along with this, it is possible to apply channel parameters necessary to estimate the easier communication performance. Also, this has the advantage that it can be flexibly applied in implementing the communication channel with the upcoming new scenarios. The proposed module can estimate the communication performance via constellation and BER using the implemented module.