• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.463-468
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• 2009

This paper proposes a method for extending simulating fluid on mobile device, which was only possible on desktop PC. Fluid simulation is done by solving Navier-Stokes equation numerically, and previous research were mainly focused on numerical stability [1], and realism [2]. However, such methods assume rich computational resources, which is not available on mobile devices. On the other hand, rigid-body solver is the mostly used physically-based technique [3], and only simple height field-based method is released for fluid simulation [4]. To overcome these problems, we proposes a modified incompressible fluid dynamics solver for the mobile device, and also we propose a technique for visualizing fluids on the mobile device.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.6-10
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• 2009

In these days, recommendation service in mobile environments is in the limelight due to the spread of mobile devices and an increase of information owing to advancement of computer network. The restaurant recommendation system reflecting user preference was proposed. This system uses Bayesian network to model user preference and analytical hierarchical process to recommend restaurants, but static inference model for user preference used in the system has some limitations that cannot manage changing user preference and enormous user survey must be preceded. This paper proposes a learning method for Bayesian network based on user requests. The proposed method is implemented on mobile devices and desktop, and we show the possibility of the proposed method through experiments.

• Journal of the Korea Computer Graphics Society
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• v.14 no.1
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• pp.27-33
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• 2008

Mobile systems have relatively limited resources such as low memory, slow CPU, or low power comparing to desktop systems. In this paper, we present a new 3D mesh connectivity coding algorithm especially optimized for mobile systems(i.e., mobile phones). By using adaptive octree data structure for vertex positions, a new distance-based connectivity coding is proposed. Our algorithm uses fixed point arithmetic and minimizes dynamic memory allocation, appropriate for mobile systems. We also demonstrate test data to show the utility of our mobile 3D mesh codec.

• Journal of Korea Multimedia Society
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• v.19 no.12
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• pp.2014-2023
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• 2016

Web presence is one of the key issues for extensive deployment of Internet-of-Things (IoT). An obstacle to overcome for Web presence is relatively low computing power of IoT devices. In this paper, we present implementation of an IoT platform based on Constrained Application Protocol (CoAP) which is a web transfer protocol proposed by Internet Engineering Task Force (IETF) for the low performance IoT devices such as Wireless Sensor Network (WSN) nodes and micro-controllers. To qualify the performance of CoAP-based IoT system for such an application as smart grid, we designed a test platform consisting of Raspberry Pi2, Kmote WSN node and a desktop PC. Using open source softwares, CoAP was implemented on top of the platform. Leveraging the GET command defined at CoAP specification, performance of the system was measured in terms of round-trip time (RTT) from web application to the Kmote sensor node. To investigate abnormal cases among the test results, hop-by-hop delays were measured to analyze resulting data. The average response time of CoAP-based communication except the abnormal data was reduced by 23% smaller than the previous research result.

• Journal of Advanced Navigation Technology
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• v.19 no.6
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• pp.587-594
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• 2015

Open operating system, Linux is the traditional Web, E-mail, DNS, FTP server, as well as being used in Cloud and Big data infrastructure. In addition, Linux is also used like a desktop or mobile devices, smart TV and cars. In particular, stepping up to the IoT era at this time is expected to be greater proportion occupied by Linux. As the use of Linux has increased security has emerged as an important factor. User management is core of Linux system security. In this paper, Classifying Linux user and analyzed the role of the user-specific file. Finally, we analyzed the linux management technologies and useful user security tools.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.8
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• pp.863-867
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• 2010

Multi-core processors are becoming increasingly popular. As they are widely adopted in embedded systems as well as desktop PC's, many multimedia applications are being parallelized on multi-core platforms. However, it is difficult to parallelize applications with inherent data dependencies such as encryption algorithms for multimedia data. In order to overcome this limit, we propose a technique to overlap computation and communication using an otherwise idle core in this paper. In particular, we interpret the problem of multimedia computation and communication as a pipeline design problem at the application program level, and derive an optimal number of stages in the pipeline.

• Journal of Korean Library and Information Science Society
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• v.34 no.4
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• pp.43-66
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• 2003

Nowadays many academic libraries have considered and some have implemented the just-in-time(access) approach to collection development especially of scholarly journals. The adaption of the scholarly electronic journal based on access paradigm has brought a number of advantages and disadvantages to academic libraries. Electronic journals have promised rapid delivery of the latest research to the desktop through the ubiquitous platform of the Internet. But the promise of the e-journal is not yet a reality, and there are many misconceptions about what is actually available today. The objective of this paper is to analyse the probabilities of digital achilles tendon of scholarly journals resulting from a decline of purchase power, absence of selection(evaluation) criteria, superfluities and abuses of impact factor, access paradigm and halo effects, mismatching of demand-supply, md insufficiency in subject gateway functions.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.211-218
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• 2004

Compared with the desktop, the MIDP on J2ME has many limitations on memory capacity, screen size, networking ability and processing speed. In addition, screens vary with device providers in size, and service platforms vary with mobile service providers. These factors require additional functions to server and cause overheads of the server. On this paper, we propose the wav to reduce overheads of the server and to overcome disadvantages of the J2ME clients, with the server that provides the service of data in XML document type and the client on MIDP that is developed including the kXML parser.

• The KIPS Transactions:PartD
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• v.15D no.3
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• pp.327-336
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• 2008

Many XML-compliant UIDLs(User Interface Description Languages) have been developed to specify user interfaces. Although previous UIDLs are helpful to describe user interfaces of web and desktop applications, they are not available of developing UI of mobile applications. In this paper, in order to effectively specify user interfaces of MIDlet which is application model on J2ME(Java Platform, Micro Edition), we propose MIML(Midlet Interface Markup Language) and present transformation rules to generate source codes from MIML. Further, we enhance the usability of MIML through J2MERenderer which is a tool using presented rules. The proposed method can specify user interfaces of mobile applications and allow developers to keep productivity and consistency in development phase.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.6
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• pp.1186-1193
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• 2009

Wearable ECG monitoring is regarded as one of the most essential part in the ubiquitous healthcare environment and subsequently day-life monitoring of a heart condition has been pursued especially for the elder people. However, there are many problems to accomplish this task such as; i) implementation of long-term monitoring device, ii) development of non-irritating electrode on skin and iii) stable signal acquisition. With these aims, we have focused on implementing a non-irritating electrode with an endurable monitoring device for day-life. To accomplish our tasks, we basically developed four different types of textile electrodes that are adapted by both shape and the composed material; flat or convex shape and Ag-conductive paste material or not. It turns out to be that a convex shape and Ag-paste textile electrode has the best performance in terms of both signal-to-noise ratio (SNR) and Impedance/Phase characteristics. Furthermore, ECG amplifier (35 ${\times}$ 35 mm) has developed to resolve the ECG signal and transfer the signal to desktop computing device or portable one by RF serial communication.