• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.3
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• pp.180-185
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• 2005

Microstrip antennas generally have a lot of advantages that are thin profile, lightweight, low cost, and conformability to a shaped surface application with integrated circuitry. In addition to military applications, they have become attractive candidates in a variety of commercial applications such as mobile satellite communications, the direct broadcast system (DBS), global positioning system (GPS), and remote sensing. Recently, many of the researches have been achieved for improving the impedance bandwidth of microstrip antennas. The basic form of the microstrip antenna, consisting of a conducting patch printed on a grounded substrate, has an impedance bandwidth of $1\~2\%$. For improvement of narrow bandwidth of microstrip patch, we were designed U-slot microstrip patch antenna in this paper. This antenna had wide bandwidth for all personal communication services (PCS) and IMT-2000. For the design of U-slot microstrip patch antenna using a finite difference time domain(FDTD) method. This numerical method could get the frequency property of U-slot patch antenna and the electromagnetic fields of slots.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.3
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• pp.299-310
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• 2000

In this paper, we designed and implemented a personal VOD server using multi-thread for the real-time services of video data to the users. The system consists of service manager, disk manager, and network manager. The service manager controls the user admission to the system using the VBR(Variable Bit Rate) characteristics of MPEG (Moving Picture Experts Group) video data. The disk manager provides the functions for VCR-like operations. The disk manager reads blocks from the disk by the size of GOP(Group of Pictures) and buffers the data to the user's thread. The network manager uses TCP/IP for the communication between the server and the client. The communication starts from the client and the VOD server must respond to this request. The implemented personal VOD system shows an acceptable performance.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.3
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• pp.235-242
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• 2020

This paper proposes a system that can manage and verify personal career information through a block chain to solve the problem of getting a job by forging an individual's career when hiring employees. Blockchain network uses private network, and inside the block, the user's academic and career information is kept. The functions of the block chain perform the functions of block creation, block internal data retrieval, career and academic verification, which works through chain code. As a result of the performance evaluation of the proposed system, the processing time per transaction was measured at approximately 110 ms and the search time was measured at 10 ms, and it was applied to the actual system to confirm that it was available.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.205-212
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• 2019

With the rapid spread of mobile phones, users are continuously interested in using the mobile phone in connection with personal activities. Also, increasingly users want to share (transmit and receive) and save data more easily and simply in the mobile environment. This paper suggests motion recognition of mobile phone to share personal information with any people located within a certain distance using location-based service with GCM service. The suggested application is based on Google Cloud Messaging which enables asynchronous communication with the mobile applications executed in Android operating system. The requirements of light-weight mechanism can be satisfied as it is possible to access sharing of personal information easily, simply and in real time through all mobile devices anywhere.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2292-2300
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• 2015

Car rear-view camera system supplies services for safe driving and easy parking by showing the rear-view of the vehicle through a monitor when reversing the car. In this paper we researched implementation methods and technology of a Car Rear-view Camera System based on the Binary CDMA technology-new technology of wireless personal area network developed by Korea - that makes free installation without wired cables restriction and reduces installation costs. Through this research we manufactured a prototype system, and researched the implementation of camera input and monitor output modules, Binary CDMA wireless communication and application programs for wireless video transmitter and relay server.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.1
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• pp.175-179
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• 2021

With the recent increase in the proportion of single-person households, the demand for reasonable personal mobility has increased, and the "Personal Mobility" industry that can be used conveniently and concisely has grown rapidly. In fact, according to data from the Korea Transport Institute, the scale of the electric kickboards rental industry, one of the personal mobility industry sectors, is expected to expand to 200,000 units in 2022. Due to the characteristics of electric kickboards that are powered by electricity, stable and efficient battery supply is the most basic and important issue. According to recent reviews from users who have used the electric kickboard, there were cases where the use of the electric kickboard is attempted, but the battery is in a discharged state or the battery charge level is low and thus cannot be used. Therefore, this paper proposes a solar charging system for stable battery use of electric kickboards. When this system is applied, it is expected that it will not only be an eco-friendly charging method for electric kickboards, but also stably supply and demand batteries while driving.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.347-351
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• 2008

This study is concerned with the design of the communication based evaluation simulator for the development of the operational control algorithm for PRT(Personal Rapid Transit) system which has very short headway and requires accurate speed control of the vehicles to avoid the impact between the vehicles. The evaluation simulator is composed of central control system, vehicle control system, communication control system, AP for wireless communication, and monitoring system. For the mobile characteristics of the PRT vehicles wireless communication is employed for the transmission of the control and status information between the central control system and the vehicle control system. By using simple test operational control algorithm the effectiveness of the proposed evaluation simulator is shown.

• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.171-174
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• 2000

In stead of RF module which has been used conventionally in many remote measurement applications, a new type of remote measurement system based on PCS(Personal communication system) and one chip Microcontroller is proposed in this work. PCS has many advantages with respect to cost reliability, communication quality, and so on. The proposed system consists of three different modules: PCS module, micro-controller module, and sensor module. System configuration as well as illustrative experiments will be described in detail.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1441-1444
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• 2009

In this paper a platform that makes it possible the simulations of the vehicle operational control for PRT (Personal Rapid Transit) is introduced. PRT system has very short headway and requires accurate speed control of the vehicles to avoid the impact between the vehicles. The proposed platform is composed of central control system, station control system, communication control system, AP for wireless communication, and monitoring system. Simple operational test scenarios are presented and the effectiveness of the proposed platform is shown using the test scenarios.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.3
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• pp.64-70
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• 1996

In this paper, we designed a low cost data logger system using single chip microcontroller. It detects the normal and abnormal current in distribution system. A sampled analog signals are stored on RAM card(4Mbit) after digitalized by internal A/D converter. Stored data can be transmitted to the personal computer either by internal serial communication port or by external parallel communication port. The transmitted data are analyzed and displayed on personal computer.