• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.3
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• pp.421-432
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• 2013

This paper describes implementation of functions for mobile robot localization, which is one of the vital technologies for autonomous navigation of a mobile robot. There are several function libraries for mobile robot navigation. Some of them have limited applicability for practical use since they can be used only for simulation. Our research focuses on development of functions which can be used for localization of indoor robots. The functions implement deadreckoning and motion model of mobile robots, measurement model of range sensors, and frequently used calculations on angular directions. The functions encompass various types of robots and sensors. Also, various types of uncertainties in robot motion and sensor measurements are implemented so that the user can select proper ones for their use. The functions are tested and verified through simulation and experiments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.3
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• pp.563-569
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• 2007

As the mobile communication and the semiconductor technology is improved continuously, mobile contents such as the multimedia service and the 2D/3D graphics which require high level graphics are serviced recently. Mobile chips should consume small die area and low power. In this paper, we design a truncated floating-point multiplier that is useful for the 2D/3D vector graphics in mobile devices. The truncated multiplier is based on the radix-4 Booth's encoding algorithm and a truncation algorithm is used to achieve small area and low power. The average percent error of the multiplier is as small as 0.00003% and neglectable for mobile applications. The synthesis result using 0.35um CMOS cell library shows that the number of gates for the truncated multiplier is only 33.8 percent of the conventional radix-4 Booth's multiplier.

• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.1
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• pp.24-33
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• 2012

This paper describes a multi-mode LDPC decoder which supports 19 block lengths and 6 code rates of Quasi-Cyclic LDPC code for Mobile WiMAX system. To achieve an efficient implementation of 114 operation modes, some design optimizations are considered including block-serial layered decoding scheme, a memory reduction technique based on the min-sum decoding algorithm and a novel method for generating the cyclic shift values of parity check matrix. From fixed-point simulations, decoding performance and optimal hardware parameters are analyzed. The designed LDPC decoder is verified by FPGA implementation, and synthesized with a $0.18-{\mu}m$ CMOS cell library. It has 380,000 gates and 52,992 bits RAM, and the estimated throughput is about 164 ~ 222 Mbps at 56 MHz@1.8 V.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.541-542
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• 2008

We propose an architecture for a lighting engine for mobile 3D graphics. The proposed architecture has a variable pipeline depending on lighting effects and the number of lighting sources so that unnecessary operations and power consumption are minimized. We design a lighting engine basedon the proposed architecture using Verilog-HDL and synthesized it using a 0.25um CMOS standard cell library at 100MHz. The synthesis results show that it occupies 180,000 and 260,000 gates for 24bit and 32bit formats, respectively.

• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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• pp.75-80
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• 2017

Nowadays, smart phone is being popularly used for communication, entertainment, and information retrieval. While demands on video traffic over mobile networks increases sharply, the wireless link capacity is often limited to fully support the traffic demand. Therefore, the size of video data needs to be reduced to provide high quality video with limited capacity. To handle this issue, we propose a video editing system using the ffmpeg library. The proposed system can provide a high quality video with a relatively small data size, thereby facilitating the mobile streaming services and live-video games.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06c
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• pp.98-103
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• 2007

본 논문에서는 기존 인터넷이 되는 곳에서만 할 수 있었던 도서 검색과 예약.대출을 모바일로 언제 어디서나 이용할 수 있고, 사용자의 편의를 보다 극대화 시키고 유동적, 실용적인 측면에서 연구발전 시켰다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.616-618
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• 2004

본 논문은 분산환경에서의 개인 디지털 도서관 서비스 시스템 구축을 위한 새로운 모바일 멀티 에이전트 시스템을 제안한다. 이 시스템은 모바일 시스템과 분산 처리 시스템을 조합한 시스템을 사용하였으며 멀티 에이전트간 협상 알고리즘과 스케줄링 방법을 개발함으로써 개인 디지털 도서관 구축이 효율적으로 동작하도록 하였다. 제안한 시스템을 구축하여 시뮬레이션한 결과, 검색속도나 검색문서의 재활용성이 기존의 클라이언트 서버 모델보다 훨씬 효율적임을 알 수 있었다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.6
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• pp.41-56
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• 2007

In this paper, we propose a specification-based intrusion detection system for WIPI(Wireless Internet Platform for Interoperability). In proposing the system, we focused on providing lightweight code, supporting multiple languages and hardware independence. The proposed system is based on an algorithm which detects an intrusion to main API of WIPI-HAL(Handset Adaptation Layer) and defines the prototype of mIDS(mobile IDS) API group that it can be added on the HAL. Moreover, we prove apply possibility through a WIPI emulator using java library.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.6
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• pp.21-30
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• 2017

Physical computing is performed through interaction with the real world making it suitable for cultivating student abilities in computing knowledge and thought processes. Furthermore, if users can develop programs under block-coding environment, it will be more easy and more intuitive. However, the existing block coding environment has a problem that the physical devices must be continuously connected to the computer. Blockly is an open source library that adds a visual code editor linked with graphic blocks to demonstrate coding concepts through web and mobile apps. Using Blockly, we describe a development environment for physical computing on mobile platform, which combines physical computing with an established block-coding environment, and activates it through wireless communication.

• Journal of Korean Library and Information Science Society
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• v.51 no.2
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• pp.355-379
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• 2020

Digital Library System(DLS) for the school library is a key access tool for school library materials. The purpose of this study was to find ways to improve the accessibility of materials through analysis of students' information search behavior in DLS. Data were collected through recording of 42 participants' DLS search process, and questionnaire. As a result, the search success rate and search satisfaction were found to be lower when the main purpose of DLS is simple leisure reading, information needs are relatively ambiguous, and when user experiences the complicated situations in the search process. The satisfaction level of search time sufficiency was the highest, and the search result satisfaction was the lowest. Besides, there was a need to improve DLS, such as integrated search of other library collection information, the recommendation of related materials, the print output of collection location, voice recognition through mobile apps, and automatic correction of search errors. Through this, the following can be suggested. First, DLS should complement the function of providing career information by reflecting the demand of education consumers. Second, improvements to DLS functionality to the general information retrieval system level must be made. Third, an infrastructure must be established for close cooperation between school library field personnel and DLS management authorities.