• Journal of the Korea Society of Computer and Information
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• v.23 no.2
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• pp.35-43
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• 2018

In this paper, we propose a grid-based efficient routing protocol for a mobile sink in wireless sensor networks. In the proposed protocol, the network is partitioned into grids and each grid has a grid head. For the efficient routing to a mobile sink, the proposed protocol uses a mobile sink representative node to send the data to a mobile sink and grid heads are used as a mobile sink representative node. Furthermore, the proposed protocol uses nodes in the boundary of the center grid as position storage nodes. The position storage nodes store the position of a mobile sink representative node and provide source nodes with it for data delivery. With these features, the proposed protocol can reduce a lot of overhead to update the position information and improve the delay of data delivery to a mobile sink. The proposed protocol performs better than other protocols in terms of the delay and the energy consumption per node in the performance evaluation.

• ETRI Journal
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• v.33 no.4
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• pp.476-486
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• 2011

The quality of navigation service is determined by the accuracy of the available data. For existing navigation services, a full map update is provided in order to keep the map data of mobile devices current. As content and services of mobile devices have recently been diversifying, the size of map data managed in mobile devices has increased, reaching several gigabytes in size. It generally takes tens of minutes to write several gigabytes of data into mobile device storage. For traditional navigation systems, a complicated storage structure called a physical storage format (PSF) is used to assure maximum processing performance of map data in mobile devices within limited resources. Consequently, even though modified navigation map data actually affects only a portion of a map, the full map data is updated because partial updates are not possible. In this paper, a navigation system is studied to solve this difficult partial map update problem. The map air update navigation system, which is the result of this study, provides real-time partial map updating using wireless communications.

• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.107-114
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• 2005

The next generation of 3D mobile games market is becoming increasingly active, more as a result of improvement in the CPU speed of hardware phone, embarkation of 3D engines and high memory capacity, In response to this trend, popular 3D games of PS2 (PlayStation2) and popular online games are being launched as mobile games. However, mobile units have different hardware characteristics compared to those of other platforms such as the PC or the game console. Therefore, mobile game versions of the popular PC games face many limitations in many aspects such as in battery capacity, size of display, capacity of the game, and other user interface issues. Among these many limitations, study for allowing low capacity storage of the game is becoming important. In addition, realistic animation of the 3D character on the small screen of the mobile unit is more important than any other matter. The purpose of this study is to find a solution to providing realistic 3D character animation, and for decreasing the storage capacity of character animation for application in 3D mobile games.

• The KIPS Transactions:PartC
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• v.11C no.6 s.95
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• pp.843-850
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• 2004

As mobile devices prevail, requests for various services using mobile devices have increased. Requests for application services that require large data space such as multimedia, game and database [1] specifically have greatly increased. However, mobile appliances have difficulty in applying various services like a wire environment, because the storage capacity of one is not enough. Therefore, research (5) which provides remote storage service for mobile appliances using iSCSI is being conducted to overcome storage space limitations in mobile appliances. But, when iSCSI is applied to mobile appliances, iSCSI I/O performance drops rapidly if a iSCSI client moves from the server to a far away position. In the case of write operation, $28\%$ reduction of I/O performance occurred when the latency of network is 64ms. This is because the iSCSI has a structural quality that is very .sensitive to delay time. In this paper, we will introduce an intermediate target server and localize iSCSI target to improve the shortcomings of iSCSI performance dropping sharply as latency increases when mobile appliances recede from a storage server.

• International Journal of Computer Science & Network Security
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• v.23 no.10
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• pp.73-80
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• 2023

The recent growth in the use of mobile devices has contributed to increased computing and storage requirements. Cloud computing has been used over the past decade to cater to computational and storage needs over the internet. However, the use of various mobile applications like Augmented Reality (AR), M2M Communications, V2X Communications, and the Internet of Things (IoT) led to the emergence of mobile cloud computing (MCC). All data from mobile devices is offloaded and computed on the cloud, removing all limitations incorporated with mobile devices. However, delays induced by the location of data centers led to the birth of edge computing technologies. In this paper, we discuss one of the edge computing technologies, i.e., cloudlet. Cloudlet brings the cloud close to the end-user leading to reduced delay and response time. An algorithm is proposed for scheduling tasks on cloudlet by considering VM's load. Simulation results indicate that the proposed algorithm provides 12% and 29% improvement over EMACS and QRR while balancing the load.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.495-498
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• 1998

Mobile computers have restrictions for size, weight, and power consumption that are different from traditional workstations. Storage device must be smaller, lighter. Low power consumed storage devices are needed. At the present time, flash memory device is a reasonable candidate for such device. But flash memory has drawbacks such as bulk erase operation and slow program time. This causes of worse average write performances. This paper suggests a storage method which improves write performance.

• Journal of Korea Multimedia Society
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• v.8 no.10
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• pp.1383-1390
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• 2005

Mobile Multimedia Storage Server should provide to store and transfer a data that the number of concurrent datum by Personal Digital Assistant(PDA) requests in real time. simultaneously. But, While the large number of a PDA request connect to MTS (Mobile Translation Storage) server with BottleNeck problem in mobile internet environment by many constraints such as limited bandwidth can be introduced. This paper introduces an optimal method of new DVDS (Dynamic Variable Disk Scheduling) for MTS server which is based on the Weight Value to solve the BottleNeck problems that occur when transfer and store capture images through mounted digital camera on the PDA in real time simultaneously. The comparison with previous research shows that the proposed scheme provides better.

• The KIPS Transactions:PartA
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• v.16A no.5
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• pp.357-368
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• 2009

Mobile IP storage has been proposed to overcome storage limitation in the flash memory and hard disks. It provides almost capacity-free space for mobile devices over wireless IP networks. However, battery lifetime of the mobile devices is reduced rapidly because of power consumption with continuous use of a WLAN device when multimedia contents are being streamed through the mobile IP storage. This paper proposes an energy-efficient WLAN device power control technique for streaming multimedia contents with the mobile IP storage. The proposed technique consists of a prefetch buffer input/output module, a WLAN device power control module, and a reconfigurable prefetch buffer module. Besides, it adaptively determines the size of the prefetch buffer according to a quality of the multimedia contents, and it dynamically controls the power mode of the WLAN device on the basis of power on-off operations while streaming the multimedia contents. We evaluate the performance of the proposed technique on a PXA270-based mobile device that employs the embedded linux 2.6.11, Intel iSCSI reference codes, and a WLAN device. Extensive experiments reveal that the proposed technique can save the energy consumption of the WLAN device up to 8.5 times with QVGA multimedia contents, as compared with no power control.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3916-3936
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• 2014

Smartphone applications like games, image processing, e-commerce and social networking are gaining exponential growth, with the ubiquity of cellular services. This demands increased computational power and storage from mobile devices with a sufficiently high bandwidth for mobile internet service. But mobile nodes are highly constrained in the processing and storage, along with the battery power, which further restrains their dependability. Adopting the unlimited storage and computing power offered by cloud servers, it is possible to overcome and turn these issues into a favorable opportunity for the growth of mobile cloud computing. As the mobile internet data traffic is predicted to grow at the rate of around 65 percent yearly, even advanced services like 3G and 4G for mobile communication will fail to accommodate such exponential growth of data. On the other hand, developers extend popular applications with high end graphics leading to smart phones, manufactured with multicore processors and graphics processing units making them unaffordable. Therefore, to address the need of resource constrained mobile nodes and bandwidth constrained cellular networks, the computations can be migrated to resourceful servers connected to cloud. The server now acts as a bridge that should enable the participating mobile nodes to offload their computations through Wi-Fi directly to the virtualized server. Our proposed model enables an on-demand service offloading with a decision support system that identifies the capabilities of the client's hardware and software resources in judging the requirements for offloading. Further, the node's location, context and security capabilities are estimated to facilitate adaptive migration.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1033-1034
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• 2005

High resolution 2.1” QVGA LTPS LCD (190ppi) having high aperture ratio of 65% could be successfully developed using state-of-the-art SLS technology and active/gate storage structure. Cost effective P-MOS 6-Mask structure was used. Full gate and transmission gate circuits are integrated in the panel. The high aperture ratio was obtained by using active/gate capacitance structure, which can reduce storage capacitance area. The aperture ratio was increased to 65% from 49% of conventional gate/data capacitance structure. The brightness was increased from 180cd to 270cd without any degradation of optical properties such as contrast ratio, flicker or crosstalk.