• The KIPS Transactions:PartC
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• v.11C no.4
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• pp.545-554
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• 2004

WebDAV is a protocol to support collaboration among the workers in geographically distant locations through the Internet. WebDAV extends the web communication protocol HTTP/1.1 to provide a standard infrastructure for supporting asynchronous collaboration for various contents across the Internet. To provide the WebDAV functionality in legacy applications such as web-based collaborative systems or document management systems, those systems need to be implemented additionally to handle the WebDAV methods and headers information. In this paper, we developed an Apache-based WebDAV server, named DAVinci(WebDAV Is New Collaborative web-authoring Innovation)which supports the WebDAV specification. DAVinci was implemented as a form of service provider on a mod_dav Apache module. Mod_day, which is an Apache module, is an open source module to provide WebDAV capabilities in an Apache web server. We used a file system for storing resources and the PostgreSQL database for their properties. In addition, the system provides a consistency manager to guarantee that both resources and properties are maintained without inconsistency between resources and their properties.

• Journal of Korea Spatial Information System Society
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• v.1 no.2 s.2
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• pp.33-46
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• 1999

In distributed computing platforms like CORBA, wrappers are used to integrate heterogeneous systems or databases. A spatial data provider is one of the wrappers because it provides clients with uniform access interfaces to diverse data sources. The individual implementation of spatial data providers for each of different data sources is not efficient because of redundant coding of the wrapper modules. This paper presents a new architecture of the spatial data provider which consists of two layered objects : independent wrapper components and dependent wrapper components. Independent wrapper components would be reused for implementing a new data provider for a new data source, which dependent wrapper components should be newly coded for every data source. This paper furthermore discussed the issues of implementing the representation of query results in the middleware. There are two methods of keeping query results in the middleware. One is to keep query results as non-CORBA objects and the other is to transform query results into CORBA objects. The evaluation of the above two methods shows that the cost of making CORBA objects is very expensive.

• The KIPS Transactions:PartC
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• v.12C no.1 s.97
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• pp.129-136
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• 2005

WebDAV extends the web communication protocol HTTP/1.1 to provide a distributed authoring and versioning across the Internet. A property management, the principal ability of WebDAV, has many advantages for managing and utilizing additional information of server resources as well as supports a role of storage. Most WebDAV Application systems currently available are using WebDAV for providing simple storage space, not for the functionality of property management. However, to develop an advanced application such as a collaborative system based on WebDAV, it is very important to design and utilize user-defined WebDAV properties. In this paper, we propose DavSUDP(WebDAV Simple User-defined Property Definition Protocol) that describes XML-based configurations representing WebDAV user-defined properties and their processing steps. DavSUDP enables WebDAV servers to effectively manage user-defined properties in developing WebDAV-based applications. To show this, we extended the Apache mod_dav module to support DavSVDP and developed the OpenSpace in the iPlace collaborative system using the extended Apache web server.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.6
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• pp.555-561
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• 2008

This paper describes an e-Engineering framework to support collaborative design of automotive suspension systems developed at KIMM(Korea Institute of Machinery and Materials). The e-Engineering framework is proposed and developed on the base of the multi-layered software agents including engineering task agent which is generated from the domain knowledge of experts. The developed framework is aim to widely spread application to the small and medium enterprises by adopting open source technologies such as JADE (Java Agent Development Framework) and by using the independent characteristics related with applicant H/W and 81W system. This framework can provide an integrated design environment to support distributed personnel, design activities and engineering resources during product development process. For the validation of the system's applicability and efficiency, the several practical design processes for automotive suspension systems of RR/FR lower arms and RR cross member are applied and discussed.

• Journal of the Korea Convergence Society
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• v.8 no.4
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• pp.25-36
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• 2017

As smartphone users have increased in recent years, various applications have been developed and used especially for Android-based mobile devices. However, malicious applications developed by attackers for malicious purposes are also distributed through 3rd party open markets, and damage such as leakage of personal information or financial information of users in mobile terminals is continuously increasing. Therefore, to prevent this, a method is needed to distinguish malicious apps from normal apps for Android-based mobile terminal users. In this paper, we analyze the existing researches that detect malicious apps by extracting the system call events that occur when the app is executed. Based on this, we propose a technique to identify malicious apps by analyzing the sequence similarity of kernel layer events occurring in the process of running an app on commercial Android mobile devices.

• The KIPS Transactions:PartD
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• v.8D no.6
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• pp.715-722
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• 2001

In recent years, we recognize a new paradigm in the development process：From object oriented development, to the development process which has focused on the use of standard components. In recent years a lot of research related to the component-based development has been done, especially in business domain. but still there are many open and unresolved problems in this area. such as established development process for a distributed environment, formal process, infrastructure for COTS, development and management tool considering maintenance to guarantee a proper treatment of components. It also required a service and an application integration for component. In this paper, we propose cooperative information systems (CIS) that supports component based development. It must address for component based systems to achieve their full potential. We identify a set of CIS organized 3-tier which is a presentation layer, business logic layer and data control layer. We also discuss the specific roles and activities for the layers. we also define the behavior and managed information for business logic layer as core level. As an illustration of the CIS, we present a successful considerations which is widely helpful to user when they make decision in component development and assemble. Also, we expect to component reusability and efficiency in business domain.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.411-413
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• 2010

Now, smart phone markets are grows quickly. So it is needed research of CDN(Contents Delivery Network) technology for contents transmission in mobile networks. Especially the services of smart phone are focused on open platform model. So P2P(Peer to Peer) protocols will be used for mobile network because it is a distributed network architecture composed of participants that make a portion of their resources directly available to other network participants, without the need for a central server. Current research of P2P protocols for mobile network are not activated. The reason is appropriate in the mobile P2P network simulation environment, since it is not provided. So, in this paper we design a mobile P2P simulation system for CDN based on mobile P2P.

• Journal of Korea Trade
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• v.23 no.6
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• pp.113-130
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• 2019

Purpose - This paper investigates applicability of blockchain based bill of lading under the current legal environment. Legal requirements of electronic bill of lading will be analyzed based on the Rotterdam Rules and recently enacted UNCITRAL Model Law on Electronic Transferable Records. Using comparative analysis with the previous registry model for electronic bill of lading, this paper examines the advantages of blockchain based bill of lading. Design/methodology - This research reviewed previous efforts for dematerializing bill of lading with its limitation. Main features of blockchain technology which can make up for deficiencies of registry model also be investigated to analyze whether these features can satisfy the requirements for the legal validity of the negotiable electronic transport record or electronic transferable records under the Rotterdam Rules and the MLETR. Findings - Main findings of this research can be summarized as follows: Blockchain system operated in an open platform can improve transparency and scalability in transfer of electronic bill of lading by assuring easy access for transaction. Distributed ledger technology of blockchain makes it more difficult to forge or tamper with transactions because all participants equally shares identical transaction records. Consensus mechanism and timestamp in a blockchain transaction guarantee the integrity and uniqueness of a transaction. These features are enough to satisfy the requirements of electronic transferable records under the Rotterdam Rules and MLTER. Originality/value - This study has significance in that it provided implications for the introduction of electronic bill of lading by analyzing whether the blockchain based electronic bill of lading model meets the legal requirements under the current legal system prepared prior to the introduction of blockchain technology, and by presenting the advantages of the blockchain based bill of lading model through comparative analysis with the existing registry model.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.519-521
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• 2022

As appearance of diverse electric power supplies and fuel cells have been emerging, UAVs have capacity to prolong their flight missions. Nowadays, the rotary based UAVs that are commonly distributed on the open market, adapt rechargeable batteries and have around 50 centimeters in width and generally within 30 minutes in hovering flight capacities. UAV's flight time highly depends on the capacity and the weight of its batteries. To cope with the flight time, recharging methods are also being researched. their researches are mainly divided into coupled and decoupled in manner. In this article, we propose the method to refine the position more effectivly and precisely adapting QR Code and 3-D position estimation so that UAVs enable to land on the recharging system successfully.

• Journal of KIISE:Information Networking
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• v.29 no.3
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• pp.286-298
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• 2002

The Remote Procedure Call(RPC) has been traditionally used for Inter Process Communication(IPC) among precesses in distributed computing environment. As distributed applications have been complicated more and more, the Mobile Agent paradigm for IPC is emerged. Because there are some paradigms for IPC, researches to evaluate and compare the performance of each paradigm are issued recently. But the performance models used in the previous research did not reflect real distributed computing environment correctly, because they did not consider the evacuation elements for providing security services. Since real distributed environment is open, it is very vulnerable to a variety of attacks. In order to execute applications securely in distributed computing environment, security services which protect applications and information against the attacks must be considered. In this paper, we evaluate and compare the performance of the Remote Procedure Call with that of the Mobile Agent in IPC paradigms. We examine security services to execute applications securely, and propose new performance models considering those services. We design performance models, which describe information retrieval system through N database services, using Petri Net. We compare the performance of two paradigms by assigning numerical values to parameters and measuring the execution time of two paradigms. In this paper, the comparison of two performance models with security services for secure communication shows the results that the execution time of the Remote Procedure Call performance model is sharply increased because of many communications with the high cryptography mechanism between hosts, and that the execution time of the Mobile Agent model is gradually increased because the Mobile Agent paradigm can reduce the quantity of the communications between hosts.