• Journal of KIISE
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• v.42 no.6
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• pp.807-816
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• 2015

The Internet of Things (IoT) has recently been showered with much attention worldwide. Various kinds of devices, communicating with each other in the IoT, demand multiple communication technologies to coexist. In this environment, mobile devices may utilize the vertical handover between different wireless radio interfaces such as Wi-Fi and Bluetooth, for efficient data transfer. In this paper, an IoT broker is implemented to support the vertical handover, which can also support and manage heterogeneous devices and communication interfaces. The handover is activated based on RSSI, Link Quality values, and real time traffic. The experimental results show that the proposed handover system substantially improves QoS in Bluetooth and reduces power consumption in mobile devices as compared with a system using only Wi-Fi.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.796-808
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• 2018

The intracellular bacterium Wolbachia pipientis is widespread in arthropods. Recently, possibilities of novel Wolbachia-mediated hosts, their distribution, and natural rate have been anticipated, and the coconut leaf beetle Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae), which has garnered attention as a serious pest of palms, was subjected to this interrogation. By adopting Wolbachia surface protein (wsp) and multilocus sequence type (MLST) genotypic systems, we determined the Wolbachia infection density within host developmental stages, body parts, and tissues, and the results revealed that all the tested samples of B. longissima were infected with the same Wolbachia strain (wLog), suggesting complete vertical transmission. The MLST profile elucidated two new alleles (ftsZ-234 and coxA-266) that define a new sequence type (ST-483), which indicates the particular genotypic association of B. longissima and Wolbachia. The quantitative real-time PCR analysis revealed a higher infection density in the eggs and adult stage, followed by the abdomen and reproductive tissues, respectively. However, no significant differences were observed in the infection density between sexes. Moreover, the wsp and concatenated MLST alignment analysis of this study with other known Wolbachia-mediated arthropods revealed similar clustering with distinct monophyletic supergroup B. This is the first comprehensive report on the prevalence, infection dynamics, and phylogeny of the Wolbachia endosymbiont in B. longissima, which demonstrated that Wolbachia is ubiquitous across all developmental stages and distributed in the entire body of B. longissima. Understanding the Wolbachia infection dynamics would provide useful insight to build a framework for future investigations, understand its impacts on host physiology, and exploit it as a potential biocontrol agent.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.158-165
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• 2009

Counselling between a patient and a doctor is crucial in telemedicine. In order for the doctor to examine the patient accurately, it needs an auscultation, at least. Currently, some video conference systems are implemented but it is hard to use them in the case of an cardiac disorder, because the patients suffering from cardiac disorder cannot be examined by a stethoscope over Internet. To solve this problem, the remote counselling service has to support real time transmission of the heart sound of the patient. In this paper, we present a remote counselling system with stethoscope. We also design and implement the system in order for health monitor to connect the patient with his attending physician for the environment of u-healthcare service. The proposed system supports a mobility for doctor and patient by exchanging IP addresses at an user authentication protocol. The system implemented by this paper can be used for cardiac patients in remote clinical setting in the future.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.5
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• pp.260-270
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• 2007

Owing to the improved wireless communication technologies, it is possible to provide streaming service of multimedia with PDAs and mobile phones in addition to desktop PCs. Since mobile client devices have low computing power and low network bandwidth due to wireless network, the transcoding technology to adapt media for mobile client devices considering their characteristics is necessary. However, since mobile clients use wireless network and the wireless network have less stable bandwidth according to distance from AP and environments, it is hard to support stable QoS to mobile clients. In this paper, we propose a dynamic bit rate control method for transcoding in order to supprot stable QoS of streaming media service to mobile clients via wireless network. The proposed method is shown to serve seamless streaming media service with adaptive bit rate control according to state of wireless network in real time and to reduce transmission failure from experiment.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.458-463
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• 2015

This paper suggests detection system for the movement of patient on bed based on IEEE802.15.4 by using pressure pad and guard sensor. The system is designed to detect ordinary activities of patients on bed as well as patients' falling from the bed while sleeping at night. The node that is installed at bed sends data to gather when the pressure pad and sensor of guard detect patients' activities and falling. These data sent to gather are transmitted to monitor at help desk by TCP/IP communication. To remove unnecessary data that occurred due to switch chattering during tossing and turning, timer of MCU is used. Also, Communication module can change transmission power to apply this system to various environments of hospital room. Therefore, the nurse can take care of patients on bed in real time with data about patients' conditions.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.72-77
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• 2017

In recent years, internet of things (IoT) technology has developed rapidly and has been applied in many fields. IoT devices collect and analyze information in various environments and provide useful information to users. Due to the recent increase in IoT devices, many open source platforms based on hardware and software that are cheap and easy to use have been developed and provided. In this paper, we have studied the IoT system based on Arduino which can communicate Bluetooth wireless data with smart phone in real time. And we have developed a wireless system control app based on App Invertor 2 for communication with Android smart phone. Also, we propose an IoT system based on Arduino which can control the devices and implement the function of connectivity between devices.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.3
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• pp.405-417
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• 2001

In this paper, since we currently using surveillance system of analog type bring about waste of resource and efficiency deterioration problems, we describe new solution that design and implementation to the digital surveillance system of new type applying compression techniques and encoding techniques of image data using MPEG-2 international standard. Also, we proposed fast motion estimation algorithm requires much less than the convectional digital surveillance camera system. In this paper a fast motion estimation algorithm is proposed the MPEG-2 video encoding. This algorithm is based on a hybrid use of the block matching technique and gradient technique. Also, we describe a method of moving object extraction directly using MPEG-2 video data. Since proposed method is very simple and requires much less computational power than the conventional object detection methods. In this paper we don't use specific H/W and this system is possible only software encoding, decoding and transmission real-time for image data.

• Journal of Korea Multimedia Society
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• v.4 no.5
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• pp.377-389
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• 2001

It has a tendency to build Workflow Systems based on the web with the spread of web environment. The important function in Workflow Systems are to automatize job flow according to the predefined regulations, procedures or conditions. Hence, there needs to consider excluding passive jobs, supporting GUI and a migratory information processing for information flow. Distributed Workflow System for workflow of a distributed service system should perform transfer control and Fault-Tolerance between tasks based on process logic, and real time processing. However, the existing mail systems being used are just for transmission and it doesn't fit to automatize job flow. To solve the matter, there needs a Distributed Workflow Engine to design workflow and automatize its control. In this paper, we design a web browser with graphic interface using web mail, a browser creating a script code for a procedural performance. Also, we design a Process-engine has a Preprocessor which tolerates process scheduler for task transaction or server node's faults on distributed environment. The proposed system enhances the reliability and usability of a system reduces the cost rather than a workflow system based on database, for they execute as proxy for a server's fault or suers' absence.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11B
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• pp.1285-1296
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• 2011

Packet classification is one of the basic and important functions of the Internet routers, and it became more important along with new emerging application programs requiring real-time transmission. Since packet classification should be accomplished in line-speed on each incoming input packet for multiple header fields, it becomes one of the challenges in designing Internet routers. Various packet classification algorithms have been proposed to provide the high-speed packet classification. Hierarchical approach achieves effective packet classification performance by significantly narrowing down the search space whenever a field lookup is completed. However, hierarchical approach involves back-tracking problem. In order to solve the problem, set-pruning trie and grid-of-trie algorithms are proposed. However, the algorithm either causes excessive node duplication or heavy pre-computation. In this paper, we propose a smart set-pruning trie which reduces the number of node duplication in the set-pruning trie by the simple merging of the lower-level tries. Simulation result shows that the proposed trie has the reduced number of copied nodes by 2-8% compared with the set-pruning trie.

• Computers and Concrete
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• v.8 no.3
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• pp.293-309
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• 2011

A long-term structural health monitoring (SHM) system comprising over 700 sensors of sixteen types has been implemented on the Guangzhou Television and Sightseeing Tower (GTST) of 610 m high for real-time monitoring of the structure at both construction and service stages. As part of this sophisticated SHM system, 48 temperature sensors have been deployed at 12 cross-sections of the reinforced concrete inner structure of the GTST to provide on-line monitoring via a wireless data transmission system. In this paper, the differential temperature profiles in the reinforced concrete inner structure of the GTST, which are mainly caused by solar radiation, are recognized from the monitoring data with the purpose of understanding the temperature-induced structural internal forces and deformations. After a careful examination of the pre-classified temperature measurement data obtained under sunny days and non-sunny days, common characteristic of the daily temperature variation is observed from the data acquired in sunny days. Making use of 60-day temperature measurement data obtained in sunny days, statistical patterns of the daily rising temperature and daily descending temperature are synthesized, and temperature distribution models of the reinforced concrete inner structure of the GTST are formulated using linear regression analysis. The developed monitoring-based temperature distribution models will serve as a reliable input for numerical prediction of the temperature-induced deformations and provide a robust basis to facilitate the design and construction of similar structures in consideration of thermal effects.