• Journal of Power Electronics
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• v.8 no.4
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• pp.291-300
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• 2008

In this paper power system and drive-train for omni-directional autonomous mobile robots with multiple energy storage units are presented. Because in proposed system, which is implemented in soccer robots, the ability of power flow control from of multiple separated energy storage units and speed control for each motor are combined, these robots can be derived by more than one power source. This capability, allow robot to diversify its energy source by employing hybrid power sources. In this research Lithium ion polymer batteries have been used for main and auxiliary energy storage units because of their high power and energy densities. And to protect them against deep discharge, over current and short circuit, a protection circuit was designed. The other parts of our robot power system are DC-DC converters and kicker circuit. The simulation and experimental results show proposed scheme and extracted equations are valid and energy management and speed control can be achieved properly using this method. The filed experiments show robot mobility functions to perform the requested motion is enough and it has a high maneuverability in the field.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.676-678
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• 2002

In this work, we present the novel scheduling algorithm of the multimedia data retrieval for the mobile disk drive. Our algorithm is focused on minimizing the power consumption involved in data retrieval from the local disk drive. The prime commodity in mobile devices is the electricity. Strict restriction on power consumption requirement of the mobile device put unique demand in designing of its hardware and software components. State of the art disk based storage subsystem becomes small enough to be embedded in handhold devices. It delivers abundant storage capacity and portability. However, it is never be trivial to integrate small hard disk or optical disk drive in handhold devices due to its excessive power consumption. Our algorithm ARM in this article generates the optimal schedule of retrieving data blocks from the mobile disk drive while guaranteeing continuous playback of multimedia data.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.61-64
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• 2004

Recently, as the requirements of several mobile products come to the front, to cope with the market needs, various mobile storage applications have appeared. Therefore, the core components and technologies for mobile optical disc drives have been developed continuously. In case of the optical storage, the small sized optical pickup is necessary to realize the mobile optical disc drive, because the optical pickup height is determined by the optical parts and an actuator. In this paper, we propose the optical pickup actuator using the horizontally arranged magnetic circuit, and apply to 5mm height Small Form-factor Optical Drive.

• Transactions of the Society of Information Storage Systems
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• v.1 no.1
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• pp.1-22
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• 2005

There are two important trends in the modern information society, including digital networking and ubiquitous environment. Thus it is strongly required to develop new information storage devices such as high density storages to match the increased data capacity and small size storage devices to be applied to the mobile multimedia electronics. So far, many approaches have been studied for the high density memory, including the holographic memory, super-RENS and near-field recording using solid immersion lens (SIL) or nano-probe for the ODD (Optical Disk Drive) system, and the perpendicular magnetic recording and heat-assisted magnetic recording for the HDD (Hard Disk Drive) system. In addition, new mobile storage devices have been prepared using 0.85" HDD and 30mm ODD systems from a lot of foreign and domestic companies and institutes. In this paper, the recent technology trend for the next generation information storage system is summarized to offer a research motivation and encouragement to new researchers in this field with an emphasis on the technical issues of the increase of data capacity and decrease of device size.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.4
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• pp.32-40
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• 2007

A mobile device accesses large-sized data in object-based IP storage as an object unit over IP network. It relies heavily on a WLAN device, which has been known as one of the major power consumers. This paper designs and implements low-power object-based IP storage for mobile devices using an efficient WLAN power control. The proposed WLAN power control exploits prefetch buffer to maximize the idleness for incoming network traffic and controls available WLAN power modes to minimize the power consumption. Our experimental results reveal that the proposed WLAN control can save the total power consumption in a PXA270-based mobile device about 9% while playing the multimedia contents through an object-based IP storage device

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.16 no.3
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• pp.216-223
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• 2016

This paper proposes a new controller design method for a fork-type lifter (FTL) of a transportation mobile robot. The transportation robot needs to pick up a package from a stack on a storage shelf and move on by a planned path in a logistics center environment. The position of the storage shelf is recognized by reading a QR code on the floor, and using this position, the robot can move to reach the storage shelf and pick up the package. PID controllers and an adaptive controller are designed to control the velocity of two wheels and the position of the FTL. An adaptive controller for the lifter is designed to elevate up and down on a slideway to the correct height position of the package on the stack of the storage shelf. The simulation results show that the PID controllers can respond smoothly to the desired angular velocity and the adaptive controller can adapt quickly and correctly to the desired height.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.5-6
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• 2006

iSCSI is a block-oriented storage access protocol that enables a user to recognize a remote storage as their own local block device through general TCP/IP networks. This paper presents an alternative approach to overcome the limited storage space of mobile devices based on the iSCSI initiator driver in IPv6 environment, which was originally designed for wired networks.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.1344-1347
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• 2012

Mobile Cloud Computing services anywhere, anytime access to the Internet via a mobile terminal means to provide services, speakers are called Mobiloud. Computing processing power limitations of mobile devices, storage, due to space constraints, the tasks handled by mobile devices and data processing services to move to cloud environments. In recent years, smartphone, tablet PC and mobile device companies and individuals to spread and spread, and the content of the accelerating cloud painters, mobile cloud that can communicate with each other requires a standard service.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.711-714
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• 2004

A new design for improving the aperture ratio of bottom emission type AMOLED is investigated. In conventional, the TFT of AMOLED fabrication method is "Etch Stopper (7-mask)", so the aperture ratio is limited in 28${\sim}$33% by Cs(Storage Capacitor). A high aperture ratio TFT is designed by using BCE(Back Channel Etching 5-mask) fabrication way and the aperture ratio is up to 40% shown in 2.2"AMOLED display.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.2
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• pp.195-206
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• 1995

Higher utilization of warehouse space can be achieved by using automated mobile racking systems. Therefore, those systems may be employed for factories or distribution centers as a good option of increasing the storage capacity. In this paper, travel-time models are developed to estimate the average performance of the system assuming randomized storage. Expected travel times are determined for both single- and dual-command cycles. Two extreme input/output-point locations are considered. Some numerical results obtained from the models are given.