• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.6
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• pp.944-949
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• 1986

By improving the ability of arithmatic processing with an arithmatic processor in a microcomputer and realizing the data input system for real time analysis, an FFT analyzer that is usable within the range of audio frequency is designed and constructed. The input signal passes through a gain programmable pre-amplifier and anti-aliasing lowpass filter into an analogditital converter to be converted into digital form. The converted input data is processed by an Apple II microcomputer. The results of the processing are displayed using a microcomputer display unit and can be copied on a printer or stored in a floppy disk.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1298-1299
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• 2015

이동 로봇의 자기 위치 인식 방법으로 GPS를 많이 이용하지만 건물 내부공간에서는 위성신호 수신 장애가 있기 때문에 GPS 사용이 어렵다. 이에 대한 대안으로 다양한 형태의 실내 측위 기술에 관한 연구가 진행되어왔다. 최근에는 WiFi를 이용한 방법이 일부 상용화 되고 있으나 정밀도가 3~5m라는 한계가 있으며, LED 조명을 이용한 방법은 실용화 단계에 이르지는 못했지만 많은 연구가 진행되고 있다. 당 연구실에서도 LED조명을 기반으로 한 실내위치 인식 시스템을 개발하였으며, 지난 연구에서는 이를 이용한 이동로봇의 자율주행을 연구하였다. 본 연구에서는 지난 연구에 덧붙여 두개의 수신부를 이용하여 로봇의 방향인식오류 개선 및 이동 로봇의 자율주행을 보여주고자 한다. 제시된 시스템은 이동로봇, 조명제어장치 그리고 컴퓨터로 구성된다. 이동로봇은 상용화된 마이크로 마우스에 탑재된 조명신호 수신장치를 통하여 자신의 위치와 방향을 감지하며, 컴퓨터와의 Wi-Fi 통신으로 자신의 위치를 컴퓨터에 전송하거나 위치 명령을 수신한다. 컴퓨터에서는 수신 받은 이동로봇의 위치를 실시간으로 화면에 표시하며, 이동로봇에 전달할 위치명령을 사용자가 입력하는 기능을 제공한다. 사용자가 이동경로를 설정한 후 이동로봇으로 명령을 보내면 로봇은 자신의 위치와 목적지를 비교하며 자율주행을 하게 된다. 실험을 통하여 확인한 결과 지난연구의 방향인식의 문제점이 해결되어 제시된 시스템으로 실내공간에서도 이동로봇의 자율주행이 원만히 이루어짐을 확인하였다.

• Journal of the Korea Society of Computer and Information
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• v.18 no.6
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• pp.1-8
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• 2013

In this paper, we design and implement a firmware for low-cost small PCR devices. To minimize machine code size, the proposed firmware controls real-time tasks simultaneously only with support of the hardware interrupt, but without support of the operating system program. The proposed firmware has the host-local structure in which the firmware receives operation commands from PC and sends operation results to PC through usb communication. We implement a low-cost small PCR device with the proposed firmware loaded on microchip PIC18F4550 chip, and verify that the implemented PCR device significantly reduces cost and volume size of existing commercial PCR devices with a similar performance.

• Journal of the Korean Data and Information Science Society
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• v.25 no.6
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• pp.1467-1474
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• 2014

In this paper, we consider the two computer intensive methods for extended Euclidean algdrithm. Two methods we propose are C-programming based approach and Microsoft excel based method, respectively. Thses methods are applied to the derivation of greatest commnon devisor, multiplicative inverse for modular operation and the solution of diophantine equation. Concrete investigation for extended Euclidean algorithm with the computer intensive process is given. For the application of extended Euclidean algorithm, we consider the RSA encrytion method which is still popular recently.

• Journal of the Korea Society of Computer and Information
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• v.25 no.4
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• pp.79-86
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• 2020

In this paper, we propose an efficient emotional relaxation framework using Dijkstra algorithm based on anisotropic features. Emotional relaxation is as important as emotional analysis. This is a framework that can automatically alleviate the person's depression or loneliness. This is very important for HCI (Human-Computer Interaction). In this paper, 1) Emotion value changing from facial expression is calculated using Microsoft's Emotion API, 2) Using these differences in emotion values, we recognize abnormal feelings such as depression or loneliness. 3) Finally, emotional mesh based matching process considering the emotional histogram and anisotropic characteristics is proposed, which suggests emotional relaxation to the user. In this paper, we propose a system which can recognize the change of emotion easily by using face image and train personal emotion by emotion relaxation.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.898-901
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• 2010

최근 소셜 네트워크 서비스가 새로운 커뮤니케이션의 패러다임이 되었다. 트위터 등의 마이크로블로 그 서비스 경우 사용하기 편리하고 단순하여 많은 사용자가 존재 한다. 그리고 주제가 특정되어 있지 않아 어떠한 정보도 공유 될 수 있기 때문에 많은 양의 정보가 공유되고 있다. 하지만 기존의 소셜 네트워크 서비스에서 사용자 간의 관계 형성은 상호 간의 신청과 허용이 이루어져야만 가능하기 때문에 관계를 형성 하고 정보를 공유 하는데 있어 이런 점은 다소 불편하게 작용 된다. 또한 다양한 주제의 정보가 다수 존재하기 때문에 사용자에게 불필요한 정보까지 노출이 되어 사용자가 원하는 정보를 찾는데 어려우며 않은 시간이 낭비 되는 문제점이 있다. 그리고 학교 자체적으로 운영 되고 있는 커뮤니티 사이트의 경우 학생들을 위한 시스템이지만 불편한 인터페이스, 낮은 접근성, 늦은 피드백 등으로 학생들의 참여도가 낮고 공유 되고 있는 정보의 양이 적은 문제점이 있다. 본 논문에서 기술하는 시스템은 사용자가 수강하는 특정 강의를 기반으로 사용자 간의 관계를 자동형성 한다. 그러므로 정보를 찾는데 있어 선행 되어야 할 많은 작업에 소요 되는 노력과 시간을 줄여준다. 또한, 강의 기반의 자동 관계 형성으로 인하여 공유되고 있는 많은 정보들 중에서 사용자가 원하는 정보를 찾기가 간편하다. 본 논문이 제안하는 시스템은 이미 형성 된 관계 혹은 조직에서 사용할 수 있는 소셜 네트워크 서비스로 발전될 것으로 사료 된다.

• Journal of Educational Research in Mathematics
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• v.15 no.4
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• pp.489-504
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• 2005

In this paper, we design a environment in computers and mathematics education. For this purpose, we study two different points of view about relations between computers and mathematics education. As theoretical background, we also study constructionism and microworld. Next, we introduce functionization as a basic principle for computers and mathematics education. The concept of functionization focuses on the variation of mathematical objects, and it is a basic concept of both mathematics and computer science. We consider the concept of functionization as a paradigm for the research and practice of the computers and mathematics education. We also present the concept of functionization as a principle for designing a computer environment. Finally, we use the concept of functionization to integrate two famous microworlds, LOGO and DGS by introducing such objects as tiles and folding nets. Combining LOGO and DGS, we design a new microworld that can be used under the internet environment. We present tiles and folding nets to introduce how the concept of functionization is used to design a new microworld and to integrate two microworids.

• Archives of design research
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• v.15 no.3
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• pp.213-222
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• 2002

Graphic User Interface has been playing a great role in giving people easy access of computer. The research of implementing graphic image on the computer display and inventing mouse were the threshold of GUI's birth in 1960s, and those were succeeded to developing the first GUI based-computer at the Xerox research center in 1970s. An education theory for the children and the visual metaphor of real life environment were adapted to implement GUI. They were continuously studied and tested in the beginning of creating the GUI concept and design method. In 1980s, the GUI concept and design method were generally applied to all personal computer development. Apple and Microsoft have led the commercialization of their GUI based-05, and also got their own positions in the market as GUI standards in 1990s. The first research for the GUI based-computer implementation in Xerox has established very clear concept and design methods. This GUI standards are evolving Into more convenient and natural ways in various computing environment and developing technologies these days.

• Journal of Energy Engineering
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• v.20 no.4
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• pp.353-357
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• 2011

An embedded two-axis solar tracking system was developed by using AVR micro controller for enhancing solar energy utilization. The system consists of an Atmega128 micro controller, two step motors, two step drive modules, CdS sensors, GPS module and other accessories needed for functional stability. This system is controlled by both an astronomical method and an optical method. Initial operation is performed by the result from the astronomical method, which is followed by the fine controlled operation using the signals from Cds sensors. The GPS sensor generates UTC, longitude and latitude data where the solar tracker is installed. A database of solar altitude, azimuth, and sunrise and sunset times is provided by UART (Universal Asynchronous Receiver/Transmitter).

• Journal of the Microelectronics and Packaging Society
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• v.30 no.3
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• pp.1-10
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• 2023

Recently, as the demand for high-performance computers and mobile products increases, semiconductor packages are becoming high-integration and high-density. Therefore, in order to transmit a large amount of data at once, micro bumps such as flip-chip and Cu pillar that can reduce bump size and pitch and increase I/O density are used. However, when the size of the bumps is smaller than 70 ㎛, the brittleness increases and electrical properties decrease due to the rapid increase of the IMC volume fraction in the solder joint, which deteriorates the reliability of the solder joint. Therefore, in order to improve these issues, a layer that serves to prevent diffusion is inserted between the UBM (Under Bump Metallization) or pillar and the solder cap. In this review paper, various studies to improve bonding properties by suppressing excessive IMC growth of micro-bumps through additional layer insertion were compared and analyzed.