• The KIPS Transactions:PartA
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• v.13A no.4 s.101
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• pp.295-304
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• 2006

Java has been established as one of the most widely-used languages owing to its support of object-oriented concepts, safety, and flexibility. Garbage collection in the Java virtual machine is a core component that relieves application programmers of difficulties related to memory management. In this paper, we propose a memory manager and a garbage collector that is implemented on a embedded java virtual machine. The memory manager divide a heap into various-sized cells and manages it as blocks of same-sized cells. So it is possible to allocate and free memory fast. We adopted the 3-color based Mark & Sweep garbage collector as our base algorithm and we propose 4-color based Mark & Sweep garbage collector for supporting multi-threaded program. The proposed garbage collector occurs memory fragmentation but we show through a experiment that the fragmentation ratio is almost fixed according as we create objects continuously.

• Spatial Information Research
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• v.20 no.5
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• pp.111-118
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• 2012

Survey control points managed by national and local governments are associated with civilian's property and they are very important national facilities. Despite the importance of surveying results, Database and mark of survey control points, there are many problems noticed of the management aspects such as manpower, systems, and related law. Currently, each local government has built and operated Geographic Information System(GIS) independently by National Geographic Information Systems(NGIS) results. but it is still difficult to have the integration, linking and utilizing. Therefore, In this study proposed the functional improvement of GIS based control points integrated system for providing information and management and the establishment of first-payment system due to the moving of control points. Through this studies will be able to solve the problem of recovery charges according to unknown contractor and establish the basis of manager and user-centric one-stop integration system.

• Journal of Information Technology Applications and Management
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• v.9 no.1
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• pp.97-110
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• 2002

Many companies are using EDI (Electronic Data Interchange) for the electronic transmission of documents and information to and from other companies. The appearance of Internet can enhance existing EDI systems. Existing EDI systems have several problems such as poor system interoperability and high expense of VAN. This paper prognoses a new EDI system utilizing Internet to provide open communication environment by using XML (extensible Markup language) and this applies it to the EDI service for Hospital Demand. XML is a mark-up language extending HTML which is a standard language for the expression of WWW (World-Wide Web) pages. XML is more structural than HTML, thus it is more suitable for the repetitive tasks of EDI and for the maintenance of databases. XML can transmit EDI documents in the open communication environment of Internet and users can easily access the documents with web browsers. Therefore we can provide EDI services within more open environment and we can build an EDI system with lower expense.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.44-45
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• 2022

The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) has been developing the S-201 Aids to Navigation information standard since 2019 for the purpose of exchanging Aids to Navigation data. In this study, the navigation information managed in Korea was modeled using the IALA S-201 navigation information standard system for the management and service of smart navigation. By using the S-201 Aids to Navigation information standard system, the basis for reflecting the information standard system was prepared in the production, exchange, and collection of domestic navigational data. It also intends to contribute to the establishment of an information exchange system between the Aids to Navigation organization, IALA, and countries.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.4
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• pp.69-79
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• 2015

This research proposes a modified data hiding method to hide data in a slack space of an NTFS index record. The existing data hiding method is for anti-forensics, which uses traces of file names of an index entry in an index record when files are deleted in a direcotry. The proposed method in this paper modifies the existing method to make non-admittable ASCII characters for a file name applicable. By improving the existing method, problems of a file creation error due to non-admittable characters are remedied; including the non-admittable 9 characters (i. e. slash /, colon :, greater than >, less than <, question mark ?, back slash ${\backslash}$, vertical bar |, semi-colon ;, esterisk * ), reserved file names(i. e. CON, PRN, AUX, NUL, COM1~COM9, LPT1~LPT9) and two non-admittable characters for an ending character of the file name(i. e. space and dot). Two results of the two message with non-admittable ASCII characters by keyboard inputs show the applicability of the proposed method.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.516-519
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• 2014

Cloud computing is an up-and-coming paradigm shift transforming computing models from a technology to a utility. However, security concerns related to privacy, confidentiality and trust are among the issues that threaten the wide deployment of cloud computing. With the advancement of ubiquitous mobile-based clients, the ubiquity of the model suggests a higher integration in our day to day life and this leads to a rise in security issues. To strengthen the access control of cloud resources, most organizations are acquiring Identity Management Systems (IDM). This paper presents one of the most popular IDM systems, specifically OAuth, working in the scope of Mobile Cloud Computing which has many weaknesses in its protocol flow. OAuth is a Delegated Authorization protocol, and not an Authentication protocol and this is where the problem lies. This could lead to very poor security decisions around authentication when the basic OAuth flow is adhered to. OAuth provides an access token to a client, so that it can access a protected resource, based on the permission of the resource owner. Many researchers have opted to implement OpenlD alongside OAuth so as to solve this problem. But OpenlD similarly has several security flows. This paper presents scenarios of how insecure implementations of OAuth can be abused maliciously. We incorporate an authentication protocol to verify the identities before authorization is carried out.

• Journal of Internet Computing and Services
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• v.13 no.4
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• pp.33-43
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• 2012

Smart phones can be used in parking management to receive important notifications. An infrastructure based from such approach should consider message persistence which is currently supported through push notification systems. However, the broadcast method produces high overhead when sending notifications throughout the clients. This paper uses a filtering method to prevent unnecessary message overheads. The heuristic approach selects the mobile clients with corresponding preference values based on the notification tag values. The simulation result showed that the proposed filtering method was faster in re-establishing connections and had lower message overhead compared to conventional messaging frameworks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.8
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• pp.3068-3085
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• 2021

The economics of big data knowledge, especially cloud computing and statistical data of consumer preferences, has attracted increasing academic and industry practitioners' attention. Firms nowadays require purchasing not only external private patent knowledge from other firms, but also proprietary big data knowledge to support their new product development. Extant research investigates pricing strategies of external private patent knowledge and proprietary big data knowledge separately. Yet, a comprehensive investigation of pricing strategies of these two types of knowledge is in pressing need. This research constructs an overarching pricing model of external private patent knowledge and proprietary big data knowledge through the lens of firm profitability as a knowledge transaction recipient. The proposed model can help those firms who purchase external knowledge choose the optimal knowledge structure and pricing strategies of two types of knowledge, and provide theoretical and methodological guidance for knowledge transaction recipient firms to negotiate with knowledge providers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.760-767
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• 2015

First annulus formation and age determination of otoliths were examined for chub mackerel Scomber japonicus collected in Korean waters over the one year from January to December in 2009. Translucent zone was regarded as an annual mark. Age interpretation criteria was based on the data of the number of translucent zone, capture date, and edge type of the otolith, assuming the nominal birthday to be 1 January. Monthly changes in mean marginal index indicated that translucent zone was formed once a year, mainly in June. The otolith of 0-ring group was detected comparing the progression by month of the smaller fish length, appearing to be a single first opaque zone. The average distance from the core to the first translucent zone was ~1.77 mm, provided as supplementary information to increase ageing accuracy. The ageing criteria for chub mackerel was made to determine correct year-class with the purpose of effective stock assessment. This method using nominal birthdate and edge type analysis could estimate age of fish closer to the true age than purely counting the number of translucent zone on a whole otolith.

• Proceedings of the CALSEC Conference
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• 2005.11a
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• pp.78-84
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• 2005

As the research activities related to 'Ubiquitous Computing' whose concept was introduced by Mark Weiser are growing, RFID(Radio Frequency Identification) technology has recently gained attention as a technology to advance the ubiquitous computing and a lot of related researches are also in progress. Research works done so far are mainly linked to the situation that the research outputs apply to meet the requirements for asset tracking and data sharing with partners over supply chain by using fixed RFID readers. However, it is essential that users have access to real-time information about the tagged objects and services whenever and wherever they want in the era of ubiquitous computing, so mobile devices-including PDA, smart phone, cellular phone, etc - which are equipped with an RFID reader can be regarded as an essential terminal for users living in ubiquitous computing environment. As far as the application with mobile devices are concerned, there are many considerations due to their limited capabilities of data processing, battery consumption and so on. In this paper, we review the generic RFID network model and introduce the revised RFID network model in consideration of incorporation with mobile devices equipped with an RFID reader. Also, we derive the requirements for software embedded within an RFID- enabled mobile terminal and then discuss essential components for implementation. Moreover, we develop the applications for asset management at museum by using mobile RFID network model.