• The Magazine of the IEIE
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• v.25 no.5
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• pp.31-41
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• 1998

With the advent of portable electronic systems, power consumption has recently become a major issue in circuit and system design. Furthermore, the sophisticated fabrication technology makes it possible to embed more functions and features in a VLSI chip, consequently calling for both higher performance and lower power to deal with the ever growing complexity of system algorithms than in the past. VLSI designers should cope with two conflicting constraints, high performance and low power, offering an optimum trade off of these constraints to meet requirements of system. Historically, VLSI designers have focused on performance improvement, and power dissipation was not a design criteria but an afterthought. This design paradigm should be changed, as power is emerging as the most critical design constraint. In VLSI design, low power design can be accomplished through many ways, for instance, process, circuit/logic design, architectural design, and etc.. In this paper, a few low power design examples, which have been used in 8 bit micro-controller core, and can be used also in 4/16/32 bit micro-controller cores, are presented in the areas of circuit, logic and architectural design. We first propose a low power guidelines for micro-controller design in SAMSUNG, and more detailed design examples are followed applying 4 specific design guidelines. The 1st example shows the power reduction through reduction of number of state clocks per instruction. The 2nd example realized the power reduction by applying RISC(Reduced Instruction Set Computer) concept. The 3rd example is to optimize the algorithm for ALU(Arithmetic Logic Unit) to lower the power consumption, Lastly, circuit cells designed for low power are described.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.544-545
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• 2015

오늘날 자동차에서 배출되는 유해 가스로 인한 지구 온난화를 막기 위하여 많은 환경규제를 받고 있다. 때문에 대부분의 국가들은 출시되는 자동차나 운행 중인 자동차에 대하여 배출가스 검사를 의무적으로 실시하여 배출가스에 의한 대기오염을 줄일 수 있도록 법제화하고 있다. 본 논문에서는 "배출가스 검사/진단시스템" 개발에 대한 고찰을 통하여 배출가스, RPM, 소음을 측정할 수 있는 MCU(micro controller unit) 기반의 데이터 계측기에 대한 설계방안을 제시하고자 한다. 또한, MCU를 기반으로 배출가스(HC, CO, CO2 등) 데이터 확보를 위한 광학 필터처리 기술 및 신호처리 알고리즘을 검토하였다. 자동차의 RPM을 측정할 수 있는 알고리즘에 대한 검토와 배출가스 및 소음을 측정할 수 있는 알고리즘을 개발하여 RS-485, TCP/IP 기반으로 데이터를 전송할 수 있는 배출가스 검사시스템을 제시하고자 한다.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.167-168
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• 2006

This paper is concerned about the development system that the bead width's size can be controlled. In order to control the bead width, DC motor driving slide on auto carriage is used. The adjustment of bead width is carried by amplitude and weaving shape is controlled by MCU(Micro Controller Unit). We confirmed the result by tracking experiments.

• Journal of Industrial Technology
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• v.32 no.A
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• pp.109-114
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• 2012

In this paper, We studied LED(Light Emitted Diode) sensor lights system using PIR(Pyroelectric Infrared Ray) sensor, CdS and MCU(Micro Controller Unit). And applied the valley fill circuit to improve the power factor. We designed the amplifier for each sensor and the LED driver for constant current which is the buck converter. Also, we proposed the algorithm of LED control by each sensors using MCU. Experimental results showed that power factor is 92% with valley fill circuit.

• Journal of the Korea Safety Management & Science
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• v.17 no.3
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• pp.363-370
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• 2015

In this paper, the control technique of the stepping motor using back electromotive force(B-EMF) without encoder is investigated. The stepping motor generally uses the rotary encoder to detect the rotor position. Since this method increases the cost and the motor configuration size, the new closed-loop control method applied for the B-EMF was implemented by using current detect circuit, AD-converter, and micro controller unit(MCU). The control loop of stepping motor became very simplified. The current change of stepping motor measured by the amplifier was measured and analyzed, when the missing step is occurred. Based on the data from current feedback, position errors were compensated and confirmed by using AD-converter.

• Proceedings of the Korean Society of Computer Information Conference
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• 2024.01a
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• pp.141-144
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• 2024

이 논문은 현대의 불규칙한 기후 환경에 주요한 영향을 미치는 탄소 배출을 감소시키기 위한 현실적인 방안을제공하고자 한다. 우산 대여시스템은 일회용 우산구매 시 사용 절제를 장려할 수 있는 시스템으로, 사용 시 지속해서 탄소 배출을 감소시킬 수 있다. 사용자는 자신이 위치한 곳에 가까운 대여소를 애플리케이션으로 선택 후 대여가 가능하며 대여한 곳과 다른 대여소에도 반납할 수 있다. 지난 몇 년간 시행됐던 아날로그식에 단점인 회수율을 시민의식이라는 신념에만 의존하지 않고 NFC 보안과 Node MCU 통신 탑재를 통해 효율적으로 다양한 상업이나 공공기관에서 확장될 수 있을 것으로 기대한다.

• Journal of IKEEE
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• v.19 no.3
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• pp.304-310
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• 2015

A SCALDO(Supercapacitor Assisted LDO) regulator is a new regulator having advantages of a SMPS(Switch Mode Power Supply) which has a good efficiency and a LDO(Low Drop-out) regulator which has stable output characteristics and good EMI(Electro Magnetic Interference) characteristics. However, a conventional SCALDO regulator needs a lot of power consumption to control its switches and it drops an efficiency of the circuit. In this paper, to reduce switching power consumption and improve an efficiency of the circuit, a new SCALDO regulator adopting MOSFETs as its switching parts is proposed and it is found out that the proposed SCALDO regulator has the maximum 9.5% higher efficiency than the conventional SCALDO regulator. We also try to simplify production process of the circuit by changing switching control method of the circuit from MCU(Micro-controller unit) based firmware control to hardware control using a comparator and a T-F/F(Flip Flop).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.10
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• pp.728-737
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• 2019

In this study, the minimized on-board computer (OBC) module for integrated navigation is developed, which provides satellites' relative position information in formation flying and cluster operation situations. The scalability is considered to apply the user-selected wireless communication module and Global Positioning System (GPS) receiver for navigation, while considering to meet the structural design standard of nano-satellites. As a result of the product development and production, the processing speed of integrated navigation and real-time data synchronization is satisfied for cluster operation nano-satellites by using micro controller unit (MCU). From a heat/vacuum, vibration and radiation test, the OBC was confirmed to be operated in space environments. From these results, a mass production system of OBC was made which is a key part of development on satellite formation flying and cluster/constellation missions that the community demands are increasing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.29-36
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• 2009

In this paper, we proposed auto exposure(AE) algorithm and hardware implementation for apply to mobile phone camera. AE is a function that control camera exposure automatically for appropriate to object. Existing AE is using micro controller unit and there are some problems about high expense and slow processing speed. For improve these problems, we proposed AE algorithm for hardware implementation without micro controller unit therefor we can expect improvement about the content of a production and operation speed. We proposed the algorithm that is considered efficiency of hardware resource and the results of hardware implementation of proposed AE algorithm apply to mobile phone camera sensor, we verified proposed AE function.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.6
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• pp.375-382
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• 2022

This paper proposes a multi-core cooperative computing structure considering the heterogeneous features of automotive embedded on-chip software. The automotive embedded software has the heterogeneous execution flow properties for various hardware drives. Software developed with a homogeneous execution flow without considering these properties will incur inefficient overhead due to core latency and load. The proposed method was evaluated on an target board on which a automotive MCU (micro-controller unit) with built-in multi-cores was mounted. We demonstrate an overhead reduction when software including common embedded system tasks, such as ADC sampling, DSP operations, and communication interfaces, are implemented in a heterogeneous execution flow. When we used the proposed method, embedded software was able to take advantage of idle states that occur between heterogeneous tasks to make efficient use of the resources on the board. As a result of the experiments, the power consumption of the board decreased by 42.11% compared to the baseline. Furthermore, the time required to process the same amount of sampling data was reduced by 27.09%. Experimental results validate the efficiency of the proposed multi-core cooperative heterogeneous embedded software execution technique.