• Journal of Computing Science and Engineering
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• v.5 no.2
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• pp.141-149
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• 2011

Many distributed and heterogeneous services and devices are accessible in ubiquitous computing environment, so interoperating those services and devices is one of the key tasks in implementing ubiquitous applications. We used to use script languages in integrating such interoperating components and services. However currently available most script languages are not suitable for ubiquitous environment because there are so diverse forms of interoperation targets such as service objects, web, legacy objects and programmable devices. So it is worthwhile designing a new script language well-suited to ubiquitous environment. In this paper, we propose a new script language, called Ubiscript, for the ubiquitous environment. We develop and adopt several unique language features such as remote scope, multiple contexts, web and legacy objects, remote exception handling, etc. in Ubiscript to overcome the limitations of conventional script languages. In this paper, we also describe the implementation of Ubiscript and its runtime system. A couple of ubiquitous applications were developed in Ubiscript, and the applications are tested on the runtime system. According to our experiences and evaluation, Ubiscript turned out to have a high potential in its expression power and contribution to improving ubiquitous application developers' productivity.

• The Journal of Society for e-Business Studies
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• v.21 no.4
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• pp.151-159
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• 2016

The user interface is an important factor in providing efficient services to application users. In particular, mobile applications that can be executed anytime and anywhere have a higher priority of usability than applications in other domains.Previous studies have used prototype and storyboard methods to improve the usability of applications. However, this approach has limitations in continuously identifying and improving the usability problems of a particular application. Therefore, in this paper, we propose a usability analysis method using touch gesture data. It could identify and improve the UI / UX problem of the application continuously by grasping the intention of the user after the application is distributed.

• Smart Structures and Systems
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• v.1 no.4
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• pp.325-338
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• 2005

Utilizing robotic based reconfigurable nodal structural health monitoring systems has many advantages over static or human positioned sensor systems. However, creating a robot capable of traversing a variety of civil infrastructures is a difficult task, as these structures each have unique features and characteristics posing a variety of challenges to the robot design. This paper outlines the design and implementation of a novel robotic platform for deployment on ferromagnetic structures as an enabling structural health monitoring technology. The key feature of this design is the utilization of an attachment device which is an advancement of the common magnetic base found in the machine tool industry. By mechanizing this switchable magnetic circuit and redesigning it for light weight and compactness, it becomes an extremely efficient and robust means of attachment for use in various robotic and structural health monitoring applications. The ability to engage and disengage the magnet as needed, the very low power required to do so, the variety of applicable geometric configurations, and the ability to hold indefinitely once engaged make this device ideally suited for numerous robotic and distributed sensor network applications. Presented here are examples of the mechanized variable force magnets, as well as a prototype robot which has been successfully deployed on a large construction site. Also presented are other applications and future directions of this technology.

• Spatial Information Research
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• v.19 no.1
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• pp.127-133
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• 2011

Recently, with the advances in sensor techniques and net work computing, Ubiquitous Sensor Network (USN) has been received a lot of attentions from various communities. The sensor nodes distributed in the sensor network tend to continuously generate a large amount of data, which is called stream data. Sensor stream data arrives in an online manner so that it is characterized as high-speed, real-time and unbounded and it requires fast data processing to get the up-to-date results. The data stream has many application domains such as traffic analysis, physical distribution, U-healthcare and so on. Therefore, there is an overwhelming need of a USN middleware for processing such online stream data to provide corresponding services to diverse applications. In this paper, we propose a novel USN middleware which can provide users both context-aware service and meaningful sequential patterns. Our proposed USN middleware is mainly focused on location based applications which use stream location data. We also show the implementation of our proposed USN middleware. By using the proposed USN middleware, we can save the developing cost of providing context aware services and stream sequential patterns mainly in location based applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.732-735
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• 2011

Cloud computing is a new paradigm that adopts a pay-as-you-go business model. So, clients can ues the various resources, although they have not own the resources. Already, three big players of IT industry, namely Amazon, Google and Microsoft, develop the many applications for cloud computing. In this paper, we describe the data consistency requirements for cloud computing. Data characteristics of cloud computing is replicated, distributed and large-scaled. And consistency and availability of data cannot be satisfied simultaneously. In this paper, we categorized the applications of cloud computing, and describe requirements of consistency criteria for applications. With this result, we can make the base of consistency criteria that can be adapted for cloud computing, in the near future.

• Journal of the Korean Society of Combustion
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• v.9 no.3
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• pp.27-35
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• 2004

Diode laser absorption sensors are advantageous because they may provide fast, sensitive, absolute, and selective measurements of species concentration. These systems are very attractive for practical applications owing to its compactness, resonable cost, robustness, and ease of use. In addition, diode lasers are fiber-optic compatible and thus enable simultaneous measurements of multiple species along a line-of-sight. Recent advances of room-temperature, near-IR and visible diode laser sources for telecommunication, optical data storage applications make it possible to be applied for combustion diagnostics based on diode laser absorption spectroscopy. Therefore, combined with fiber-optics and high sensitive detection strategies, compact and portable sensor systems are now appearing for variety of applications. The objectives of this research are to develope a new gas sensing system and to verify feasibility of this system. Wavelength and power characteristics as a function of injection current and temperature are experimentally found out. Direct absorption spectroscopy has been demonstrated in these experiments and has a bright prospect to this diode laser system.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.1
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• pp.26-36
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• 2021

The Internet was created as a decentralized and autonomous system of interconnected computer networks used for data exchange across mutually trusted participants. The element technologies on the Internet, such as inter-domain and intra-domain routing and DNS, operated in a distributed manner. With the development of the Web, the Web has become indispensable in daily life. The existing web applications allow us to form online communities, generate private information, access big data, shop online, pay bills, post photos or videos, and even order groceries. This is what has led to centralization of the Web. This centralization is now controlled by the giant social media platforms that provide it as a service, but the original Internet was not like this. These giant companies realized that the decentralized network's huge value involves gathering, organizing, and monetizing information through centralized web applications. The centralized Web applications have heralded some major issues, which will likely worsen shortly. This study focuses on these problems and investigates blockchain's potentials for decentralized web architecture capable of improving conventional web services' critical features, including autonomous, robust, and secure decentralized processing and traceable trustworthiness in tamper-proof transactions. Finally, we review the decentralized web architecture that circumvents the main Internet gatekeepers and controls our data back from the giant social media companies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1594-1617
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• 2018

In this paper, we consider a spectrum access scenario which consists of two groups of users, namely Primary Users (PUs) and Secondary Users (SUs) in Cooperative Cognitive Radio Networks (CCRNs). SUs cooperatively relay PUs messages based on Amplify-and-Forward (AF) and Decode-and-Forward (DF) cooperative techniques, in exchange for accessing some of the spectrum for their secondary communications. From the literatures, we found that the Conventional Distributed Algorithm (CDA) and Pragmatic Distributed Algorithm (PDA) aim to maximize the PU sum-rate resulting in a lower sum-rate for the SU. In this contribution, we have investigated a suit of distributed matching algorithms. More specifically, we investigated SU-based CDA (CDA-SU) and SU-based PDA (PDA-SU) that maximize the SU sum-rate. We have also proposed the All User-based PDA (PDA-ALL), for maximizing the sum-rates of both PU and SU groups. A comparative study of CDA, PDA, CDA-SU, PDA-SU and PDA-ALL is conducted, and the strength of each scheme is highlighted. Different schemes may be suitable for different applications. All schemes are investigated under the idealistic scenario involving perfect coding and perfect modulation, as well as under practical scenario involving actual coding and actual modulation. Explicitly, our practical scenario considers the adaptive coded modulation based DF schemes for transmission flexibility and efficiency. More specifically, we have considered the Self-Concatenated Convolutional Code (SECCC), which exhibits low complexity, since it invokes only a single encoder and a single decoder. Furthermore, puncturing has been employed for enhancing the bandwidth efficiency of SECCC. As another enhancement, physical layer security has been applied to our system by introducing a unique Advanced Encryption Standard (AES) based puncturing to our SECCC scheme.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.149-153
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• 2009

Physics-based distributed rainfall-runoff models are now commonly used in a variety of hydrologic applications such as to estimate flooding, water pollutant transport, sedimentation yield and so on. Moreover, it is not surprising that GIS has become an integral part of hydrologic research since this technology offers abundant information about spatial heterogeneity for both model parameters and input data that control hydrological processes. This study presents the development of a distributed rainfall-runoff prediction system for the Guem river basin ($9,835km^2$) using an Object-oriented Hydrological Modeling System (OHyMoS). We developed three types of element modules: Slope Runoff Module (SRM), Channel Routing Module (CRM), and Dam Reservoir Module (DRM) and then incorporated them systemically into a catchment modeling system under the OHyMoS. The study basin delineated by the 250m DEM (resampled from SRTM90) was divided into 14 midsize catchments and 80 sub-catchments where correspond to the WAMIS digital map. Each sub-catchment was represented by rectangular slope and channel components; water flows among these components were simulated by both SRM and CRM. In addition, outflows of two multi-purpose dams: Yongdam and Daechung dams were calculated by DRM reflecting decision makers' opinions. Therefore, the Guem river basin rainfall-runoff modeling system can provide not only each sub-catchment outflow but also dam inand outflow at one hour (or less) time step such that users can obtain comprehensive hydrological information readily for the effective and efficient flood control during a flood season.

• Journal of KIISE:Software and Applications
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• v.31 no.11
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• pp.1505-1518
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• 2004

We propose an extremely light DDXMI approach for semi-automated integration of both structurally and semantically heterogeneous distributed XML documents. In the proposed prototype, a DDXMI(Distributed Documents XML Metadata Interface) is defined and a user interface generator is developed. The prototype takes sources' DTDs as inputs and generates a friendly graphical user interface for the application users. The user can easily describe the semantic mapping between the integrated virtual database DTD and sources' DTDs through assigning index numbers and specifying associated function names so that the DDXMI based on the mappings is automatically generated. Quilt is selected as the XML query language which processes user queries according to the DDXMI. It is assumed that the application users know what they want from the different sources, that is, they have their own integrated database schema in their mind, and know the semantics of the involved XML databases. A small-size global DTD and a mid-size global DTB are generated to verify the rluery generation and retrieval results with 3 XML document databases, that is, Master/ph.D thesis, research reports, and journal databases. The system has been developed with JavaCC and Java Servelet.