• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2B
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• pp.225-231
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• 2010

In this paper, a sensor network system for providing u-health services is suggested and is implemented. It steadily collects biological data of resident people and automatically detects emergency situations. LEID (Lighting Embedded Information Device) nodes are the most essential component of the sensor network. They embed sensor network technology into lightening devices which are indispensable to most living spaces. To verify practicality of the proposed u-health system, a prototypical system is realized in the Smart Home Industrialization Support Center at Kookmin University, and is tested within many practical circumstances. The proposed u-health system can be used at various places where many patients are continuously cared.

• Journal of electromagnetic engineering and science
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• v.15 no.3
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• pp.134-141
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• 2015

The effect of a 60 Hz time-varying electric field was studied using a facing-electrode device (FED) and a coplanar-electrode device (CED) for further investigation of the genotoxicity of 60 Hz time-varying magnetic field (MF) from preceding research. Neither a single 30-minute exposure to the CED or to the FED had any obvious biological effects such as DNA double strand break (DSB) and apoptosis in cancerous SCC25, and HeLa cells, normal primary fibroblast IMR90 cells, while exposures of 60 Hz time-varying MF led to DNA damage with induced electric fields much smaller than those used in this experiment. Nor did repetitive exposures of three days or a continuous exposure of up to 144 hours with the CED induce any DNA damage or apoptosis in either HeLa or IMR90 cells. These results imply that the solitary electric field produced by time-varying MF is not a major cause of DSBs or apoptosis in cancer or normal cells.

• Journal of The Korean Association of Information Education
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• v.16 no.2
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• pp.189-199
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• 2012

Recently with the advent of smart devices, various educational apps are being developed for smart learning. However, the existing native apps to run on a particular device, the device is not compatible. A new way to develop apps, webapp written using the HTML5 has the advantage of cross-platform support. We developed the webapp using HTML5 for learning lever in elementary school science curriculum. We conducted an expert evaluation for the web app of educative usability. The expert group was comprised of elementary school teacher. In result, it was evaluated lever learning content and webapp have high educational value.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.2
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• pp.53-59
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• 2010

Android that was made by Google and Open Handset Alliance is the open source software toolkit for mobile phone. In a few years, Android will be used by millions of Android mobile phones and other mobile devices, and become the main platform of application developers. In this paper, we develop an application contents Booky based on Google Android flatform by using Webview merits and Google search engine. The features of the developed content are as follows. First, a mobile-based Web browser which has an advanced screen resolution and can support more faster viewer than normal web browser as it reduces the amount of data transmission. Second, efficient E-book search and reading functionality. In the performance evaluation, we show the results of simulation using AVD(Android Virture Device).

• International journal of advanced smart convergence
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• v.6 no.3
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• pp.29-37
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• 2017

The current behavior recognition system don't match data formats between sensor data measured by user's sensor module or device. Therefore, it is necessary to support data processing, sharing and collaboration services between users and behavior recognition system in order to process sensor data of a large capacity, which is another formats. It is also necessary for real time interaction with users and behavior recognition system. To solve this problem, we propose fog cloud based behavior recognition system for human body sensor data processing. Fog cloud based behavior recognition system solve data standard formats in DbaaS (Database as a System) cloud by servicing fog cloud to solve heterogeneity of sensor data measured in user's sensor module or device. In addition, by placing fog cloud between users and cloud, proximity between users and servers is increased, allowing for real time interaction. Based on this, we propose behavior recognition system for user's behavior recognition and service to observers in collaborative environment. Based on the proposed system, it solves the problem of servers overload due to large sensor data and the inability of real time interaction due to non-proximity between users and servers. This shows the process of delivering behavior recognition services that are consistent and capable of real time interaction.

• Journal of Korea Multimedia Society
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• v.8 no.2
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• pp.137-153
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• 2005

This paper presents a transcoding method that dynamically adapts Web pages to various devices. The proposed method is based on a CC/PP profile that is a standard description of a device's context information. Additionally, to support a sophisticated transcoding, we define an annotation schema for representing additional information about original contents. Since a mobile device has a screen of limited size, A Web page is splitted into many small ones. Our method constructs a navigation-map that represents the hierarchical relations among the splitted pages. Experimental results with various Web contents show that the proposed method is superior in terms of user's convenience of navigation and the transcoding Quality.

• Journal of Biomedical Engineering Research
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• v.26 no.4
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• pp.243-249
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• 2005

The number of people who have lost limbs due to amputation has increased due to various accidents and diseases. Numerous attempts have been made to provide these people with prosthetic devices. These devices are often controlled using myoelectric signals. Although the success of fitting myoelectric signals (EMG) for single device control is apparent, extension of this control to more than one device has been difficult. The lack of success can be attributed to inadequate multifunctional control strategies. Therefore, the objective of this study was to develop multifunctional myoelectric control strategies that can generate a number of output control signals. We demonstrated the feasibility of a neural network classification control method that could generate 12 functions using three EMG channels. The results of evaluating this control strategy suggested that the neural network pattern classification method could be a potential control method to support reliability and convenience in operation. In order to make this artificial neural network control technique a successful control scheme for each amputee who may have different conditions, more investigation of a careful selection of the number of EMG channels, pre-determined contractile motions, and feature values that are estimated from the EMG signals is needed.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.4
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• pp.436-445
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• 2011

As automation systems become intelligent and autonomous for productibility, industrial networks (fieldbuses) and network-based devices are essential components of intelligent manufacturing systems. However, there are obstacles for the wide acceptance of the network-based devices such as smart sensor and network-based actuator. First, there exist numerous fieldbus protocols that a network-based device should be able to support. Second, the whole network-based device has to be replaced when only the sensor of the module fails. In order to overcome these obstacles, a smart sensor/actuator is implemented as two units; one responsible for network communication and the other for sensor/actuator operations using IEEE 1451.0 standard. This paper presents a structure of the 1451.0-based smart sensor with multiple connectivity function designed by CANopen.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5253-5270
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• 2016

With device-to-device (D2D) communications, an inactive user terminal can be utilized as a relay node to support multi-hop communication so that connective experience of the cell-edge user as well as the capacity of the whole system can be significantly improved. In this paper, we investigate the spectrum sharing for a cooperative relay assisted D2D communication underlying a cellular network. We formulate a joint relay selection and channel assignment problem to maximize the throughput of the system while guaranteeing the quality of service (QoS) requirements of cellular users (CUs) and D2D users (DUs). By exploiting coalition formation game theory, we propose two algorithms to solve the problem. The first algorithm is designed based on merge and split rules while the second one is developed based on single user's movement. Both of them are proved to be stable and convergent. Simulation results are presented to show the effectiveness of the proposed algorithms.

• Journal of the Korean Solar Energy Society
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• v.33 no.2
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• pp.56-63
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• 2013

Daylighting system is an alternative lighting system using daylight collecting device, light transformer and light diffuser. In this paper, we developed a daylighting system in which the collecting device composed by dual parabolic reflectors, the silica optical fiber adapted to the light transformer and light diffuser made of the polyglass square sheet. We have estimated the system efficiency and general color rendering index(Ra) of the developed system. The system efficiency measured to 23.8% and Ra was revealed as 95. Ra number of the developed system is bigger than the number(65) of the previous fresnel lens based sunlight collector.