• Spatial Information Research
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• v.7 no.2
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• pp.209-221
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• 1999

In this research, AVL-GIS(Automatic Vehicle Location System linked with Geographic Information System) system was developed using integration of core techniques of GIS engine written by Java language, GOS(Global Positioning System) and wireless telecommunication interfacing techniques. IDGPS(Inverted differential GPS) techniques was employed to estimate accurate position of mobile vehicle and to supervise their path from AVL-GLS control center system. Between mobile vehicle and AVL-GLS control center system which has spatial data analysis function, road network and rleate ddata base were connected wireless phone to communicate for position an dmessage in real time. The developed system from this research has more enhanced GIS functions rather than previous AVL oriented system which has MDT for message display and voice communication only. This system can support build-up application system such as fleet management like bus, taxi, truck, disaster and emergency and monitoring of transportation status for customer s order via web browser in filed of EC/CALS in low cost.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.279-286
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• 2010

Hypersonic aircraft technologies have been developed with increase in flight speeds. As hypersonic flight speeds increase, heat loads on an aircraft and it's engine increase. Researches on cooling technologies using endothermic fuels are progressing in the USA, France, and Russia to treat the heat loads. Endothermic fuels are liquid hydrocarbon aircraft fuels which are able to absorb the heat loads by undergoing endothermic reactions, such as thermal and catalytic cracking. In this study, methylcyclohexane, n-octane, and n-dodecane were selected as model endothermic fuels and experiments in endothermic properties were implemented. Experimental conditions were supercritical phase of each model fuels in which actual endothermic fuels were exposed. The object of this study is to identify endothermic properties of the model endothermic fuels and to predict endothermic properties of actual fuels such as kerosene fuels.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.820-824
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• 2010

The purpose of this study is to develop basic technology of hybrid rocket vehicle by constructed and launched. This small hybrid rocket using HDPE/LN2O and Aluminium steel for its body (weight : 12.5 kg, diameter : 114 mm, height : 1.8 m) was designed. The fuel grain and injector were designed for 50 kgf thrust and burning time 2.5 sec. This rocket was loaded the data acquisition device for obtaining data of pressure and velocity during its flying and equiped an automatic ejector system using spring/motor and timer to collect the rocket more safely after launching. It was launched successfully, but found some problem that the rocket's weight was heavier than expected and the thrust was not enough to reach the designed altitude and analyzed its flight path way.

• Journal of Aerospace System Engineering
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• v.12 no.2
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• pp.23-29
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• 2018

Contrail is type of clouds which are formed by a condensation of water vapour from the aircraft exhaust when the aircraft is flying the cold atmosphere. Since contrails have considerable effect on greenhouse-effect and military stealth efficiency, researches about contrail avoidance technology has been conducted for decades. However, none of the previous researches concerning contrail avoidance was carried out in Korea. Thus, review of the previous study regarding contrail reduction is absolutely needed. In this paper, researches conducted by several countries are categorically introduced, and practicabilities of their methods are analyzed. This paper also suggests some practical and systematized way to conduct future researches about contrail avoidance.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.5
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• pp.579-585
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• 2014

For the application of fuel cell systems on ship which is future eco-friendly ship technology, it is need that the modification of relevant laws and regulations with relevant technical development. This paper reviews the trend of fuel cell development, SOLAS and IACS UR/UI as a international regulations, international standardization trend such as IMO MEPC, IMO BLG and major classification rules, the consideration for the standard development of ship fuel cell systems, the implications for application of fuel cell systems on ships in Korea. The IGF Code which is developing in the IMO included fuel cell, and thus Korean government and related company should participate in the codification. The analysis of development of IMO's relevant regulations also needed for the preparations.

• Journal of Korea Society of Industrial Information Systems
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• v.8 no.4
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• pp.64-72
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• 2003

A Web crawler is an important Internet software technology used in a variety of Internet application software which includes search engines. As Internet continues to grow, implementations of high performance web crawlers are urgently demanded. In this paper, we study how to support dynamic scheduling for a multiprocess-based web crawler. For high peformance, web crawlers are usually based on multiprocess in their implementations. In these systems, crawl scheduling which manages the allocation of web pages to each process for loading is one of the important issues. In this paper, we identify issues which are important and challenging in the crawl scheduling. To address the issue, we propose a dynamic crawl scheduling framework and subsequently a system architecture for a web crawler with dynamic crawl scheduling support. And we analysed the behaviors of Web crawler. Based on the analysis result, we suggest the direction for the design of high performance Web crawler.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.3
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• pp.429-442
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• 2020

The proportion of attacks via office documents is increasing in recent incidents. Although the security of office applications has been strengthened gradually, the attacks through the office documents are still effective due to the sophisticated use of social engineering techniques and advanced attack techniques. In this paper, we propose a method for detecting malicious OOXML(Office Open XML) documents and a framework for detection. To do this, malicious files used in the attack and benign files were collected from the malicious code repository and the search engine. By analyzing the malicious code types of collected files, we identified six "suspicious object" elements that are meaningful in determining whether they are malicious in a document. In addition, we implemented an OOXML document-based malware detection framework based on the detection method to classify the collected files and found that 98.45% of malicious filesets were detected.

• Journal of the Korean Society for information Management
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• v.28 no.1
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• pp.89-104
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• 2011

Large-scaled information extraction plays an important role in advanced information retrieval as well as question answering and summarization. Information extraction can be defined as a process of converting unstructured documents into formalized, tabular information, which consists of named-entity recognition, terminology extraction, coreference resolution and relation extraction. Since all the elementary technologies have been studied independently so far, it is not trivial to integrate all the necessary processes of information extraction due to the diversity of their input/output formation approaches and operating environments. As a result, it is difficult to handle scientific documents to extract both named-entities and technical terms at once. In order to extract these entities automatically from scientific documents at once, we developed a framework for scientific core entity extraction which embraces all the pivotal language processors, named-entity recognizer and terminology extractor.

• Journal of KIISE:Databases
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• v.36 no.4
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• pp.321-326
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• 2009

Since the existing Web search engines don't sufficiently reflect user's search intent, it is very difficult to find out accurate information that users want to find. Therefore, a lot of researches, study for personalized search, to enhance satisfaction of Web search results by analyzing search pattern and applying it to search are in progress in these days. Web searchers can more efficiently find information and easily obtain appropriate information through the personalized search. In this paper, we propose the personalized search based on community through the analysis of web users' query patterns and interest. Consequently, when applying query frequency, interest and community to web search, we are able to the confirm that the search results which hit to the search intent of the individual are provided.

• Journal of Information Management
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• v.41 no.4
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• pp.141-163
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• 2010

It's getting popularized to collect information connecting web sites with massive information through the internet and advanced search engines. Users can handle digital materials like E-book wherever the internet is available and they will demand digital information increasingly. This study analyzes literature investigation, statistics analyses of the attached library of Kyushu University, drawings and field investigation to suggest a new model of a library which handles traditional paper-formed materials and digital-formed materials at one place with growing importance of digital materials. It results that a library performs a important role like a learning space and functions as a sociocultural communication space. Also it shows that it is required to basically reinvestigate the role of 'space' in the library with a great importance of digital materials. In the hybrid library combined with subjects and reorganized at one place, One-stop services like library materials and manpower can be provided for users staying at the same area.