• 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.

• 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.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.43-52
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• 2018

Livestock production is the second largest economic activity of Pakistan's rural population, more specifically; sixty-seven percent of Pakistan's total population that live in rural areas sources their income from livestock activities. As this subsector of agriculture within rural Pakistan is so critical to Pakistan's economy it is especially important to further develop the sector through the introduction of cost effective, efficient, and practical technologies. In an effort to improve such an important sector within the agriculture sector in Pakistan research has been carried out to better understand the capabilities and feasibility of leveraging Internet of Things based technologies, such as, microprocessors and microcontrollers within Pakistan's livestock production and management. The internet of Things can potentially allow for the scaling of small-scale rural livestock production to larger operations through cost effective and efficient livestock management through the application of IoT technologies. This paper discusses the architecture models of IoT based smart animal farms and delves into the pitfalls and advantages of applying IoT technologies in this sector. In this work we will explore the cheap sensors to monitor the internal activities of cattle farm with the aim of using these sensors as part of system to detect the important operations that need on the time response. This system should provide the feed and water as required, and control the temperature in sheds to protect the cattle being ill and on heat, and humidity level .internet connection used to connect these devices with smartphones or computers. In this paper we proposed the architecture model of IoT based smart animal farm.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.7 no.3
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• pp.41-48
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• 1993

본 논문에서는 신속하고 정확한 동특성 응답이 요구되는 직류 서보 전동기의 위치제어용 퍼지제어기의 설계 문제를 다루었다. 제안된 퍼지제어기는 PC 80386 마이크로 컴퓨터에 의한 Lyapnov 함수 연산부와 퍼지제어 루틴부로 구성되었다. 직류 서보 시스템에 적용시킨 결과, 종래의 P 및 PID 제어기등에 비해 도달시간과 오버슈트, 외란특성등의 제어 성능이 크게 향상되었다.

• Proceedings of the Korean Society for Information Management Conference
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• 1997.08a
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• pp.183-186
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• 1997

고문헌의 텍스트와 이미지를 디지털 방식으로 축적하여 제공하는 사례가 많아지고 있다. 전자화된 고문헌은 기존의 보존방안이었던 영인본이나 마이크로필름의 단점을 극복하고, 네트워크와 발달된 정보기술을 통해 매우 효율적인 정보이용수단을 제공할 수 있다. 본 연구에서는 영국 Electronic Beowulf와 한글과컴퓨터사의 삼국사기 CD 96의 사례를 분석하여 고문헌을 디지털 방식으로 축적하고자 할 때 고려해야 할 사항을 제시하고, 이렇게 축적된 정보자원이 어떻게 이용자의 정보요구를 충족시킬 수 있을지 활용방안을 논하고자 한다.

• Journal of the KSME
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• v.34 no.3
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• pp.168-176
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• 1994

축 이송운동의 오차를 측정할 수 있는 광전소자 측정시스템이 구현되었으며, 결론은 다음과 같다. 1) 광전소자와 레이저광원을 이용하여 축이송시에 발생하는 5개의 운동오차를 동시에 검출하는 측정방법이 개발되었으며, 이때의 정밀도는 마이크로미터오더이다. 2)광전소자에 대한 2차원 칼리브레이션이 수행되었으며, 비선형성을 고려할 때 더욱 정밀한 측 정값을 얻을 수 있었다. 3) 레이저간섭기 등에 의해서 측정이 어려운 롤(roll)오차의 측정방법이 구현되었으며, 이때 빔 분리기의 오차를 칼리브레이션할 때, 정밀한 측정값이 얻어질 수 있었다. 4)광전소자측정시스템을 마이크로 컴퓨터와 연계함으로써, 종래의 측정방법보다 매우 빠르며, 정밀한 측정시스템이 구현되었다.

• Journal of the Korean Society for Precision Engineering
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• v.5 no.3
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• pp.63-70
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• 1988

This paper presents the development of a microcomputer-aided design program for a SISO control system. The program has been written in GWBASIC language which is suitable for Intel 80861 CPU with 640KB memory. By utilizing this program, sampling time, the number of bits for the A/D and D/A converter, and the stability for the digital control system can be determined. To demonstrate the utility of this program, a microcomputer controlled precision temperature control system has been employed as an example.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.61-63
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• 2002

컴퓨터 및 네트워크 기술의 눈부신 성장은 PDA, MP3 플레이어, 디지털 카메라와 같은 임베디드 시스템의 급성장을 가져왔다. 이러한 임베디드 시스템에는 그 시스템의 목적에 맞도록 특화된 실시간 운영체제가 탑재되게 되고, 그에 맞게 각 저장 장치들을 제어할 수 있는 파일 시스템도 필요하다. 본 논문에서는 삼성전자에서 개발한 CalmRISC16 마이크로 프로세서 코어를 사용하는 임베디드 시스템에 탑재될 실시간 운영체제를 위한 임베디드 파일 시스템을 구현하였다. 부 논문에서 구현된 임베디드 파일 시스템은 가상 과인 시스템으로 동작하며 In-memory 파일 시스템과 FAT를 사용하는 SmartMedia를 지원한다.