• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.1
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• pp.88-92
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• 2014

This paper presents an application of a multiphase interleaved converter in tracking maximum power points (MPPs) of a photovoltaic (PV) panel regardless of environmental variations. Maximum power from the panel was extracted by means of the well-known the perturb-and-observe (P&O) method. The switching control technique used an interleaving scheme based on multi-unit synchronization. The converter performed harmonic attenuation without affecting the tracking speed. This approach is straightforward, reliable and inexpensive, and could be applied to any higher number of switching cells without difficulty.

• Journal of Korea Spatial Information System Society
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• v.6 no.1 s.11
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• pp.51-58
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• 2004

Mobile Mapping System is an effective wav to obtain position and image using vehicle equipped with GPS(Global Positioning System), IMU(Inertial Measurement Unit), and CCD camera. It have been used various fields of load facility management, map upgrade and etc. It is difficult to upgrade Mobile Mopping System which is developed from abroad and add other sensors because we don't know the way to integrate and synchronize multi-sensors. In this paper, we present the effective way of the integration and synchronization method for multi sensors we designed and manufactured Synchronization equipment by considering sensors of laser, odometer and etc.

• ETRI Journal
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• v.30 no.1
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• pp.59-67
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• 2008

The necessity for the precise time synchronization of measurement data from multiple sensors is widely recognized in the field of global positioning system/inertial navigation system (GPS/INS) integration. Having precise time synchronization is critical for achieving high data fusion performance. The limitations and advantages of various time synchronization scenarios and existing solutions are investigated in this paper. A criterion for evaluating synchronization accuracy requirements is derived on the basis of a comparison of the Kalman filter innovation series and the platform dynamics. An innovative time synchronization solution using a counter and two latching registers is proposed. The proposed solution has been implemented with off-the-shelf components and tested. The resolution and accuracy analysis shows that the proposed solution can achieve a time synchronization accuracy of 0.1 ms if INS can provide a hard-wired timing signal. A synchronization accuracy of 2 ms was achieved when the test system was used to synchronize a low-grade micro-electromechanical inertial measurement unit (IMU), which has only an RS-232 data output interface.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1B
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• pp.86-92
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• 2011

In this paper, we propose a novel hardware MPI(Message Passing Interface) unit which supports message passing in multiprocessor system which use distributed memory architecture. MPI Hardware unit processes data synchronization, transmission and completion, and it supports processor non-blocking operation so it reduces overhead according to synchronization. Additionally, MPI hardware unit combines ready entry, request entry, reserve entry which save and manage the synchronized messages and performs the multiple outstanding issue and out of order completion. According to BFM(Bus Functional Model) simulation result, the performance is increased by 25% on many to many communication. After we designed MPI unit using HDL, with synopsys design compiler we synthesized, and for synthesis library we used MagnaChip $0.18{\mu}m$. And then we making prototype chip. The proposed message transmission interface hardware shows high performance for its increase in size. Thus, as we consider low-cost design and scalability, MPI hardware unit is useful in increasing overall performance of embedded MPSoC(Multi-Processor System-on-Chip).

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.57-61
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• 2006

As high speed internet users are tremendously increasing, three are keenly in need of development of high speed portable internet technology which can provide high quality wireless internet service cheaply even in the mobile. Unlike the FDD-CDMA, TDD-OFDMA has relatively poor wave environment with inducing interference, fading and delay because it agrees to multi-carrier modulation method and time-division radio telecommunication system. To solve this problem, it is necessary to develop repeater operating by digital signal processing method which have more strict wireless channel control and wave signal processing technology over TDD telecommunication equipments. This thesis is dealing with design and implementation of Digital RF Repeater which implemented 'Synchronization Acquisition Unit', 'TDD signal switching Unit', 'Feedback Signal Cancellation Unit'. Over this argument, we will develop digital RF repeater with more cheap, more adaptive in wave environment like oscillation control, adaptive wave monitoring and output increasing and having control function as a result it will be helpful for success in high speed portable internet service business.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.73-82
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• 2009

Due to the many advantages including low price, low power consumption, and miniaturization, the CMOS camera has been utilized in many applications, including mobile phones, the automotive industry, medical sciences and sensoring, robotic controls, and research in the security field. In particular, the 360 degree omni-directional camera when utilized in multi-camera applications has displayed issues of software nature, interface communication management, delays, and a complicated image display control. Other issues include energy management problems, and miniaturization of a multi-camera in the hardware field. Traditional CMOS camera systems are comprised of an embedded system that consists of a high-performance MCU enabling a camera to send and receive images and a multi-layer system similar to an individual control system that consists of the camera's high performance Micro Controller Unit. We proposed the SL-AVS (Small Size/Low power Around-View System) to be able to control a camera while collecting image data using a high speed synchronization technique on the foundation of a single layer low performance MCU. It is an initial model of the omni-directional camera that takes images from a 360 view drawing from several CMOS camera utilizing a 110 degree view. We then connected a single MCU with four low-power CMOS cameras and implemented controls that include synchronization, controlling, and transmit/receive functions of individual camera compared with the traditional system. The synchronization of the respective cameras were controlled and then memorized by handling each interrupt through the MCU. We were able to improve the efficiency of data transmission that minimizes re-synchronization amongst a target, the CMOS camera, and the MCU. Further, depending on the choice of users, respective or groups of images divided into 4 domains were then provided with a target. We finally analyzed and compared the performance of the developed camera system including the synchronization and time of data transfer and image data loss, etc.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.2
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• pp.16-22
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• 2008

So far, Korean command post vehicles(CPs) have used voice-only radio communication among the mechanized troop units such MBTs and IFVs, etc. But digital data communication technology should be introduced to improve mission success capabilities and accommodate integrated combat capabilities through increasing SA(situation Awareness), or spatiotemporal synchronization of military operation in battle field environment. Therefore, conventional CPs, which have been operated without digital network, urgently needs to mount a battle management system which furnish with tactical information network, considering that korean new MBTs or new IFVs will be fielded soon. This study suggests some performance enhancement method which might be applicable to CPs which have a role of connecting Battalion unit to Brigade C4I system.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.1
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• pp.99-103
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• 2012

This paper presents a new switch-control approach for multiphase interleaved converters. Development of the proposed technique is based on control-signal generation for multi-unit synchronization. Current sharing among the switching cells and voltage regulation are achieved by means of a multi-loop control scheme regardless of changes in input voltage and load. System stability is ensured by single-pole compensation. This proposed technique is straightforward, reliable and inexpensive, and can be applied to any higher number of cells without difficulty.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.167-172
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• 2004

모바일 매핑시스템은 차량에 GPS(Global Positioning System), IMU(Inertial Measurement Unit), CCD 카메라 등을 탑재하고 공간 및 속성 정보를 취득하는 효율적인 방법이다. 모바일 매핑시스템은 도로 시설물 관리, 지도 갱신 등 다양한 분야에 이용되고 있다. 국외에서 개발된 모바일 매핑 시스템을 업그레이드하거나 새로운 센서를 추가 하고자 할 때 기존 시스템의 센서 통합 및 동기화 방안을 알 수 없으므로 시스템의 개선 및 향상이 어렵다. 본 연구에서는 모바일 매핑시스템의 개선 및 센서추가를 위해서 모바일 매핑시스템에 기본적으로 필요한 GPS, IMU, 그리고 CCD 카메라 등의 효율적인 통합 및 동기화 구현 방안을 제시하고, 동기화에 필요한 각 센서의 요구사항을 파악한 후 동기화 장비를 설계 및 제작하였다. 또한, 향후 추가될 센서인 레이져, 오도미터(Odometer) 등을 센서가 추가될 경우를 고려하여 통합장비를 설계하였다.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.05a
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• pp.129-133
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• 2005

This paper describes the methodology of connecting MASTER (Multi-purpose Analyzer for Static and Transient Effects of Reactors) to simulator system, system configuration, and previous test. The actual simulator environment for Youngkwang Unit1 has been developed. It is impossible for the simulator server to execute MASTER code by limitation of computer performance. So, environment of distributed system was developed, and it had a synchronization task. As MASTER and simulator module should be synchronized in different device, the connection of communication was tested and verified.