• Journal of KIISE:Software and Applications
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• v.34 no.3
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• pp.226-234
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• 2007

In this paper, we develop a speech recognition system using a throat microphone. The use of this kind of microphone minimizes the impact of environmental noise. However, because of the absence of high frequencies and the partially loss of formant frequencies, previous systems developed with those devices have shown a lower recognition rate than systems which use standard microphone signals. This problem has led to researchers using throat microphone signals as supplementary data sources supporting standard microphone signals. In this paper, we present a high performance ASR system which we developed using only a throat microphone by taking advantage of Korean Phonological Feature Theory and a detailed throat signal analysis. Analyzing the spectrum and the result of FFT of the throat microphone signal, we find that the conventional MFCC feature vector that uses a critical pass filter does not characterize the throat microphone signals well. We also describe the conditions of the feature extraction algorithm which make it best suited for throat microphone signal analysis. The conditions involve (1) a sensitive band-pass filter and (2) use of feature vector which is suitable for voice/non-voice classification. We experimentally show that the ZCPA algorithm designed to meet these conditions improves the recognizer's performance by approximately 16%. And we find that an additional noise-canceling algorithm such as RAST A results in 2% more performance improvement.

• Smart Media Journal
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• v.4 no.4
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• pp.24-32
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• 2015

Recently, SDN is actively used as datacenter networks and gradually increase its applied areas. Along with this change of networking environment, research of deploying network security systems on SDN becomes highlighted. Especially, systems for detecting network flooding attacks by monitoring every packets through ports of OpenFlow switches have been proposed. However, because of the centralized management of a SDN controller which manage multiple switches, it may be substantial overhead that the attack detection system continuously monitors all the flows. In this paper, a sampling based network flooding attack detection and prevention system is proposed to reduce the overhead of monitoring packets and to achieve reasonable functionality of attack detection and prevention. The proposed system periodically takes sample packets of network flows with the given sampling conditions, analyzes the sampled packets to detect network flooding attacks, and block the attack flows actively by managing the flow entries in OpenFlow switches. As network traffic sampler, sFlow agent is used, and snort, an opensource IDS, is used to detect network flooding attack from the sampled packets. For active prevention of the detected attacks, an OpenDaylight application is developed and applied. The proposed system is evaluated on the local testbed composed with multiple OVSes (Open Virtual Switch), and the performance and overhead of the proposed system under various sampling condition is analyzed.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.21-35
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• 2009

KOMPSAT-2 is the seventh high-resolution image satellite in the world that provides both 1m-grade panchromatic images of the GSD and 4m-grade multispectral images of the GSD. It's anticipated to be used across many different areas including mapping, territory monitoring and environmental watch. However, due to the complexity and security concern involved with the use of the MSC, the use of KOMPSAT-2 images are limited in terms of geometric images, such as satellite orbits and detailed mapping information. Therefore, this study aims to produce DEM and orthoimage by using the stereo images of KOMPSAT-2, and to explore the applicability of geo-spatial information with KOMPSAT -2. Orientation interpretations were essential for the production of DEM and orthoimage using KOMPSAT-2 images. In the study, they are performed by utilizing both RPC and GCP. In this study, the orientation interpretations are followed by the generation of DEM and orthoimage, and the analysis of their accuracy based on a 1:5,000 digital map. The accuracy analysis of DEM is performed and the results indicate that their altitudes are, in general, higher than those obtained from the digital map. The altitude discrepancies on plains, hills and mountains are calculated as 1.8m, 7.2m, and 11.9m, respectively. In this study, the mean differences between horizontal position between the orthoimage data and the digital map data are found to be ${\pm}3.081m$, which is in the range of ${\pm}3.5m$, within the permitted limit of a 1:5,000 digital map. KOMPSAT-2 images are used to produce DEM and orthoimage in this research. The results suggest that DEM can be adequately used to produce digital maps under 1:5,000 scale.

• Archives of design research
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• v.11 no.1
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• pp.291-302
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• 1998

This paper covers the development process of multimedia evaluation system, especially focused on customer satisfactory factors while customers navigating net-based Interactive multimedia system. Customers usually experience new level of interaction cased by newly developed web-based technology In ordinary multimedia system. However, if it gives customers satisfactory experience is a matter of question. To find out the relationship between customer satisfaction and interactivity factors exposed by multimedia system, a model has been developed which describes the structure of web-based multimedia system and its relation to customer satisfactory factors. Five different experiments, including 'semantic differential', 'focus group interview', and 'expert review', has been conducted and four customer satisfactory factors were identified. Those are 'customery value', 'structural perfectness', 'visual perfectness', and 'contemporaneity'. With these factors and newly delveoped evaluation system, 7 different web-site has been evaluated and analyzed at the end of this report.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.6
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• pp.221-228
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• 2018

With an increase in demand for the high added value of shipbuilding and marine industry based on the information and communications technology (ICT), software technology has become more important than ever in the industry. In this paper, we present the result of our preliminary investigation on the current software development environment in the shipbuilding and marine industry in order to develop reusable software component, which can enhance the competitiveness of software development. The investigation is performed based on the survey answers from 34 developers who are working in different shipbuilding and marine companies. The questionnaire is composed of items to gather the information of each company such as the number of employees and product domain, and actual software development environment such as operating system, programming languages, deployment format, obstacles for developing components, and the adoption of software development methods and tools. According to the results of the survey, the most important consideration to select their development platform was the number of available utilities and the technical supports, followed by performance, price and security problems. In addition, the requirements of various platforms supporting and the higher reliability, and the limitations of low development cost and manpower made it difficult for them to develop reusable software components. Finally, throughout the survey, we find out that only 15% of developers used software development processes and managed the quality to systematically develop their software products, therefore, shipbuilding and marine companies need more technical and institutional support to improve their ability to develop high qualified software.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.4
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• pp.53-65
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• 2011

As the Information and Communication Technologies continue to advance, some sensitive services (e.g. e-commerce, on-line financial service, and etc.) have spread rapidly. Accordingly, ensuring the safety of the sensitive service itself using personal Information as well as the protection of personal Information Is becoming very important. In addition, with the popularization of smart phone and the universalized use of wireless Internet, many services that have been provided on the basis of the conventional wired network are increasingly propagating to wired and wireless converged network environment. These changes in the network environment requires new paradigm for the pursuit of safe and stable communication. In this paper, we propose seamless and secure service framework that can facilitate a sustainable secure connection between the user terminal and the sensitive service system by using both the personal and network Information. The proposed service framework is capable of isolating the source of authorized use by a third party of the personal Information as far as the user terminal is not lost, although some personal Information is disclosed. Besides, it can provide a seamless and safe service environment even if the access network is changed by relocation of terminals in the heterogeneous mobile network environment.

• KSBB Journal
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• v.17 no.6
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• pp.571-576
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• 2002

Recombinant E. coli DH5 ${\alpha}$/pSB311 was made by cloning the genes encoding bacterial luciferase and aldehyde substrate proteins from Photohabdus luminescense, to complement defects of Lumistox, which is normally used in bioassays to monitor toxic substances in water environmental systems. The conditions for stable light production by the recombinant strains were investigated with respect to cell growth stage, cell number, and buffer conditions. The optimum growth stage was a middle-exponential stage with an OD$_{660nm}$ value of 0.6-0.7. ADout 10$^{6}$-10$^{7}$ cells per test tube was optimum for stable light emission. The effect of buffer was not significant if an optimum viable cell number was maintained. The bioluminescence of the recombinant E. coli harboring the lux operon of Photohabdus luminescense was not affected by temperature, while the bioluminescence of Lumistox was temperature sensitive. The recombinant E. coli was more sensitive to heavy metals (Cd, Cu, Hg, Zn) than Lumistox, because it does not require high concentrations of NaCl in the buffer.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.2
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• pp.165-182
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• 2001

In this paper, we describe a design and implementation of the Wireless Markup Language(WML) compiler to deploy wireless Internet services effectively. The WML compiler translates textual WML decks into binary ones in order to reduce the traffic on wireless links that have relatively low bandwidth to wireline links and mitigate the processing overhead of WML decks on, wireless terminals that have relatively low processing power to fixed workstations. In addition, it takes over the overhead of eXtensible Markup Language(XML) well-formedness and validation processes. The WML compiler consists of the lexical analyzer and parser modules. The granunar for the WML parser module is LALR(1) context-free grammar that is designed based on XML 1.0 and WML 1.2 DTD(Document Type Definition) with the consideration of the Wireless Application Protocol Binary XML grammar. The grammar description is converted into a C program to parse that grammar by using parser generator. Even though the tags in WML will be extended or WML DTD will be upgraded, this approach has the advantage of flexibility because the program is generated by modifying just the changed parts. We have verified the functionality of the WML compiler by using a WML decompiler in the public domain and by using the Nokia WAP Toolkit as a WAP client. To measurethe compressibility gain of the WML compiler, we have tested a large number of textual WML decks and obtained a maximum 85 %. As the effect of compression is reduced when the portion of general textual strings increases relative to one of the tags and attributes in a WML deck, an extended encoding method might be needed for specific applications such as compiling of the WML decks to which the Hyper Text Markup Language document is translated dynamically.

• Information Systems Review
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• v.6 no.2
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• pp.285-305
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• 2004

This study is based on providing core infrastructure to make or extend an ERP strategy to make the proper model to cope effectively with various customer requirements and market changes through ERP improvement. The purpose of this study is to support making a competitive advantage by raising productivity and reducing costs as a result of making and applying the "mobile real time connection to ERP"model which is accessible anywhere and anytime using PDA and wireless LAN on the basis of mobile business concept. The model is implemented as the "mobile Material Management System" on the area of material management of ERP in the enterprise which already implemented ERP system. This model is also applied into other divisions of the enterprise. This case study shows that the proper application of ERP reduces costs by reducing business process lead time, increase productivity and customer satisfaction through mobility and instant connectivity and easiness of the system. It is recommended to apply this model into the ERP system which is used in most enterprise, to make a competitive advantage. To sum up, the model in this study can be applied into the enterprise which wants to reduce costs, increase productivity and customer satisfaction through ERP improvement.

• Korean Security Journal
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• no.15
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• pp.337-358
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• 2008

With the Japanese attacks on Pearl Harbor in 1941, approximately 2,500 people were killed. The terrorist attack on World Trade Center in the United States resulted in the heavy loss of people's lives, 2,749 in all. The 9.11 demonstrated that terrorist attack could be more serious problem than the war in our modern life. In addition, terrorist armed with new and high technologies have become more dangerous elements to the international community. Especially, the fact that the weapons of mass destruction are used by terrorist organizations is a matter of great concern. The strength of terrorist arsenal gives terrorist a decided advantage over us. The chances of success for terrorist have been increased due to the terrorist friendly environments. Terrorism has evolved without stopping from its birth, which is imposing a great burden on the authorities concerned. The counter-terrorism strategy and tactics used in the past have been useless in the fighting against new terrorism. To cope with the fast changing terrorism, comprehensive countermeasures should be developed. The purpose of this study is to know the enemy. To achieve the goal, the current situation on international terrorism as a whole is examined. Based on the result of the research, this paper also tried to give a perspectives on the future terrorism. At the same time, it provides a guidelines of the direction in the fighting against terrorism.