• Journal of the Korea Society of Computer and Information
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• v.20 no.8
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• pp.85-92
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• 2015

Due to the advancements in the capabilities of smart devices and home networks, we are able to easily access multimedia contents stored in a home server. In this paper, we present a wireless media content sharing mechanism for home networks that utilizes UPnP-based DLNA technology. We also present a novel Peer-to-Peer content sharing system that is able to operate on the client as well as server. Our system supports multiple push/pull services simultaneously via a multi-thread technique, and our intuitive user interface facilitates ease of use. Future studies would explore the feasibility of implementing our system in a multi-hop environment or providing a community-wide service.

• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.1
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• pp.29-38
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• 2010

It is highly requested that the more complicated embedded software is used for high performance and multiple functions of the systems. This is inevitably increasing the errors. Therefore the embedded software testing is getting important recently. There are not general testing methods which are able to be applied for any embedded systems, but via this research, we introduce a testing method which is based on TTCN-3, a testing standard, for embedded systems. A testing environment for network-based embedded software is implemented with considering the features of TTCN-3 testing which is based on message exchange. The testing environment has two additional parts with TTCN-3 test system, the network analyzer to access the network-based systems and the communication interface which is suggested for embedded systems in previous work, and we have implemented the whole testing environment with interacting these two parts. In addition to the normal testing domain, called single node testing as a unit testing of V-model, we suggest another concept to test multiple nodes in network. It could be achieved by adding keywords such as supervisor and object which are describing the feature of TTCN-3 testing component and generating the TTCN-3 Executable code which contains new keywords. The testing has done for embedded software which is based on CAN network and the demonstration of the testing environment has been shown in this paper.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.71-80
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• 2014

Recently, most mobile nodes, such as smartphones, will have multiple wireless radio interfaces. This feature allows a mobile node to access a multi-network through multiple wireless radio interfaces simultaneously. Accordingly, various networking technology has been studied to use wireless multi-interface more efficiently. In this paper, MPTCP based handover scheme is proposed to reduce data loss and end-to-end latency during the handover in PMIPv6 domain. The proposed scheme performs 2-step flow mobility on the multi-path established through the multi-interface of mobile node in the handover procedure and uses MPTCP subflow function to overcome end-to-end disconnection during the handover. Therefore, the proposed scheme takes the advantage of being able to minimize data loss and a latency generated during performing the handover of mobile node.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1A
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• pp.65-71
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• 2006

In IEEE 802.11b wireless network, the access point(AP) sends beacons periodically to manage stations when they are running in low power mode. Stations contend for the transmission medium after they receive a beacon and continuously check its state until it becomes available. Thus the energy consumption of each station increases as the load of wireless network. In this paper, we propose a method to reduce energy consumption controlling virtual bitmap in wireless network with multiple stations. The problems of low power mode in IEEE 802.11b wireless interface are described and a new method to reduce energy consumption is proposed. The proposed method is simulated with the network simulator, ns2, and compared with the low power mode of the IEEE 802.11b. The result measured in terms of station's wakeup time shows some enhancement in energy consumption when multiple stations are communicating through the AP in wireless network.

• Smart Media Journal
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• v.8 no.1
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• pp.43-50
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• 2019

As numerous devices are connected through a wireless network, there exist many studies conducted to efficiently connect the devices. While earlier studies often use clustering for efficient device management, there is a load-intensive cluster node which may lead the entire network to be unstable. In order to solve this problem, we propose a scheduling model for centralized unequal chain clustering for efficient management of sensor nodes. For the cluster configuration, this study is based on the cluster head range and the distance to the base station(BS). The main vector projection technique is used to construct clustering with concentricity where the positions of the base stations are not the same. We utilize a multiple radio access interface, multiple-input multiple-output (MIMO), for data transmission. Experiments show that cluster head energy consumption is reduced and network lifetime is improved.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.179-186
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• 2012

Nowadays, the multihomed host equipped with multiple network interfaces has been interested research in next generation wireless network, because the mobile users expect that they can be able to access services not only anywhere, at any time and from any network but also simultaneously. This paper addresses the mobility simulation model of the multihomed node for supporting MIPv4 and MIPv6 function in an interworking of Worldwide Interoperability for Microwave Access (WiMAX) and IEEE 802.11 WLAN. The multihomed node with two air interfaces has been developed based on WiMAX and WLAN workstation node model in simulation software. The main point of the developed model is to support both MIPv4 and MIPv6 function, and provide network selection policy for the multihomed node between WiMAX and WLAN network. Based on the received Router Advertisement along with the interface number, we can manage the access interfaces in ordered list to make handover decision while the multihomed node is moving. In the end of this paper, the simulation scenarios and results are shown for testing MIPv4 and MIPv6 function.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.135-135
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• 2017

The Gramene database (http://www.gramene.org) is a powerful online resource for agricultural researchers, plant breeders and educators that provides easy access to reference data, visualizations and analytical tools for conducting cross-species comparisons. Learn the benefits of using Gramene to enrich your lectures, accelerate your research goals, and respond to your organismal community needs. Gramene's genomes portal hosts browsers for 44 complete reference genomes, including crops and model organisms, each displaying functional annotations, gene-trees with orthologous and paralogous gene classification, and whole-genome alignments. SNP and structural diversity data, available for 11 species, are displayed in the context of gene annotation, protein domains and functional consequences on transcript structure (e.g., missense variant). Browsers from multiple species can be viewed simultaneously with links to community-driven organismal databases. Thus, while hosting the underlying data for comparative studies, the portal also provides unified access to diverse plant community resources, and the ability for communities to upload and display private data sets in multiple standard formats. Our BioMart data mining interface enable complex queries and bulk download of sequence, annotation, homology and variation data. Gramene's pathway portal, the Plant Reactome, hosts over 240 pathways curated in rice and inferred in 66 additional plant species by orthology projection. Users may compare pathways across species, query and visualize curated expression data from EMBL-EBI's Expression Atlas in the context of pathways, analyze genome-scale expression data, and conduct pathway enrichment analysis. Our integrated search database and modern user interface leverage these diverse annotations to facilitate finding genes through selecting auto-suggested filters with interactive views of the results.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.138-142
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• 2004

In this paper, we present a new method for monitoring of ECU's sensor signals of vehicle. In order to measure the ECU's sensor signals, the interfaced circuit is designed to communicate ECU and the Embedded Linux is used to monitor communication result through Web the Embedded Linux system and this system is said "ECU Interface Part". In ECU Interface Part the interface circuit is designed to match voltage level between ECU and SA-1110 micro controller and interface circuit to communicate ECU according to the ISO, SAE communication protocol standard. Because Embedded Linux does not allow to access hardware directly in application level, anyone who wants to modify any low level hardware must develop device driver. To monitor ECU's sensor signals the most important thing is to match serial level between ECU and ECU Interface Part. It means to communicate correctly between two hardware we need to match voltage and signal level, and need to match baudrate. The voltage of SA-1110 is 0 ${\sim}$ +3.3V and ECU is 0 ${\sim}$ +12V and, ECU's communication Line K does multiple operation so, the interface circuit is used to match voltage and signal level. In Addition to ECU's baudrate is 10400bps, it's not standard baudrate in computer environment. So, we need to develop a device driver to control the interface circuit, and change baudrate. To monitor ECU's sensor signals through web there's a network socket program is working in Embedded Linux. It works as server program and manages user's connections and commands. Anyone who wants to monitor ECU's sensor signals he just only connect to Embedded Linux system with web browser then, Embedded Linux webserver will return the ActiveX webbased measurement software. It works in web browser and inits ECU, as a result it returns sensor signals through web. All the programs are developed with GCC(GNU C Compiler) and, webbased measurement software is developed with Borland C++ Builder.

• Journal of Korea Multimedia Society
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• v.1 no.1
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• pp.98-108
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• 1998

In the multimedia tele-medical system the medical informations are stored and managed in multimedia database. Also, multimedia DBMS is essential in order to manage large scale medical informations, and the remote access function is necessary for the distributed processing at all around the hospital. For the multimedia tele-medical information that is composed of image/picture, data, video, and audio, a high-speed telecommunication network is necessary that can provide separated connections for each medical information type with different QoS. The commercial DBMSs are based on the TCP/IP socket API(Application Programming Interface) that does not provide multiple QoS. Also, each commercial DBMS has its own API that is incompatible with other DBMS. In this paper, we propose a multimedia DBMS agent for the remote access of the multimedia database in the tele-medical system. The proposed multimedia DBMS agent is based on the ATM API that can provide high-speed data transfer capability and multiple QoS connections. Also, the proposed multimedia DBMS agent is independent of the commercial DBMS. We explain the functional architecture of the multimedia DBMS agent, implementation technology on the ATM network environment, and the result of performance analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.6
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• pp.457-465
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• 2014

This paper introduces a test bed for communication protocol schemes of underwater acoustic sensor network, and also shows experimental results obtained from the test bed. As a testing protocol, carrier sense multiple access/collision avoidance (CSMA/CA) is evaluated on underwater acoustic channel. A sensor node is equipped with a DSP control board of ATmega2560 and a commercial underwater modem produced by Benthos. The control board not only manipulates a GPS signal to acquire the information of location and time, but also controls the underwater modem to operate according to the procedure designed for a given testing protocol. Whenever any event takes place such as exchanging control/data packets between underwater modems and acquiring location and timing information, each sensor node reports them through radio frequency (RF) air interface to a central station located on the ground. The four kinds of packets for CSMA/CA, RTS(Request To Send), CTS(Clear to Send), DATA, ACK(Acknowledgement) are designed according to the underwater communication environment and are analyzed through the lake experiment from the point of feasibility of CSMA/CA in underwater acoustic communications.