• Spatial Information Research
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• v.5 no.1
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• pp.77-88
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• 1997

This paper presents the design and implementaion of an object-relational geographic information system. This system has been developed on top of a commercial object-relational database management system. It provides flexible spatial data model, spatial query language, visual user interface, and efficient spatial access methods(D0T) in which traditional primary-key access methods can be applied. We report on our design choices and describe the current status of Implementation. The conceptual model of the system is based on SDTS, and is mapped to the intemal obiect-oriented data model. Kevwords : object-oriented data model, GIS, spatial data model, spatial access method.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.5
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• pp.255-264
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• 2013

Resolving of memory access latency is one of the most important problems in modern embedded system design. Recently, tons of studies are presented to reduce and hide the access latency. Burst/page data transfer modes are representative hardware techniques for achieving such purpose. The burst data transfer capability offers an average access time reduction of more than 65 percent for an eight-word sequential transfer. However, solution of utilizing such burst data transfer to improve memory performance has not been accomplished at commercial level. Therefore, this paper presents a new technique that provides the maximum utilization of burst transfer for memory accesses with local variables in code by reorganizing variables placement.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.2
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• pp.40-46
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• 2022

Recently, as the need for data access by integrating information in a distributed cloud environment increases in enterprise-wide enterprises, interoperability for collaboration between existing legacy systems is emphasized. In order to interconnect independent legacy systems, it is necessary to overcome platform heterogeneity and semantic heterogeneity. To solve this problem, middleware was built using EMRA (Extended MetaData Registry Access) based on ISO/IEC 11179. However, the designed middleware cannot guarantee the efficiency of information utilization because it does not have an adjustment function for each node's resource status and work status. Therefore, it is necessary to manage and adjust the legacy system. In this paper, we coordinate the correct data access between the information requesting agent and the information providing agent, and integrate it by designing a cooperative agent responsible for information monitoring and task distribution of each legacy system and resource management of local nodes. to make efficient use of the available information.

• Journal of the Society of Disaster Information
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• v.17 no.4
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• pp.897-903
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• 2021

Purpose: Recently, ransomware damage that encrypts victim's data through hacking and demands money in exchange for releasing it is increasing domestically and internationally. Accordingly, research and development on various response technologies and solutions are in progress. Method: A secure storage area and a general storage area were created in the same virtual environment, and the sample data was saved by registering the access process. In order to check whether the stored sample data is infringed, the ransomware sample was executed and the hash function of the sample data was checked to see if it was infringed. The access control performance checked whether the sample data was accessed through the same name and storage location as the registered access process. Result: As a result of the experiment, the sample data in the secure storage area maintained data integrity from ransomware and unauthorized processes. Conclusion: Through this study, the creation of a secure storage area and the whitelist-based access control method are evaluated as suitable as a method to protect important data, and it is possible to provide a more secure computing environment through future technology scalability and convergence with existing solutions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6A
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• pp.820-831
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• 1999

In this paper, we have compared the performance of a D-TDMA protocol with that of a CDMA protocol, in radio access system for integrated voice/data services.The D-TDMA protocol is based on a generic dynamic channel assignment approach to be followed a combination of “circuit mode” reservation for voice calls, along with dynamic first-come-first served assignment of remaining capacity for data messages. In the CDMA protocol, we have used the voice activity detection to reduce the interface power of other mobiles in internal and external cells, and analyzed the interference power ratio. Also we have computed BER(Bit Error Rate) by using this interference power ratio and evaluated voice blocking probability(voice packet loss probability) and data transmission delay, according to average data length and average data arrival rate.We have found the CDMA protocol achieves comparatively higher performance for short data length, regardless of data arrival rate. Otherwise, the data transmission delay of D-TDMA protocol is shorter than that of the CDMA protocol for long data message.

• Journal of Korea Multimedia Society
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• v.7 no.5
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• pp.689-697
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• 2004

Rapid advances in mobile computing and the availability of wireless communications will soon provide mobile users with the ability to access data regardless of the location of the user or of the data. SRA(Static Replica Allocation) that is traditional scheme has been used for the replication method on the server. This replicates the data on the replica server after a moving host has been transferred to the cell. This strategy is simple and can easily relocate data. However, if a mobile user does not exist in the cell, the replicated data can be deleted in order to maintain data consistency. In addition to, if the mobile host leaves from replicated cell, it is difficult to access data in terms of replication route. Therefore, this paper proposes a new method of relocation based on data consistency strategy called USRAC(User Selection Replica Allocation based on Consistency) and also analyzes access cost according to the moving rate of mobile users, according to the access rate of mobile hosts, and according to the number of cells of mobile users and mobile hosts.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.63-72
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• 2011

Broadcast-based data dissemination has become a widely accepted approach of communication in the mobile computing environment. However, with a large set of data items, the expected delay of receiving a desired data increases due to the sequential nature of the broadcast channel. With the objective of minimizing this wait time, this paper explores the problem of data broadcast over multiple channels. In traditional approaches, data items are partitioned based on their access probabilities and allocated on multiple channels, assuming flat data scheduling per channel. If the data items allocated on the same channel are broadcast in different frequencies based on their access probabilities, the performance will be enhanced further. In this respect, this paper proposes a new broadcast scheduling scheme named two level dynamic programming(TLDP) which can reflect a variation of access probabilities among data items allocated on the same channel.

• Journal of Contemporary Eastern Asia
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• v.17 no.2
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• pp.200-221
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• 2018

Open Science is an umbrella term that involves various movements aiming to remove the barriers to sharing any kind of output, resources, methods or tools at any stage of the research process. While the study of open science is relatively advanced in Western countries, we know of no scholarship that attempts to understand open science in Hong Kong. This paper provides a broad-based background on the major research data management organisations, policies and institutions with the intention of laying a foundation for more rigorous future research that quantifies the benefits of open access and open data policies. We explore the status and prospects for open science (open access and open data) in the context of Hong Kong and how open science can contribute to innovation in Hong Kong. Surveying Hong Kong's policies and players, we identify both lost research potential and provide positive examples of Hong Kong's contribution to scientific research. Finally, we offer suggestions regarding what changes can be made to address the gaps we identify.

• Journal of the Korean Society for information Management
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• v.27 no.3
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• pp.125-146
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• 2010

This study developed a name access point control system for better performance of information retrieval from institutional repositories, which are equipped with authorgenerated metadata processes for self-archiving. In developing name access point control data for the system, the primary data were created from the existing authority. However, unlike the existing authority data, the primary data did not use any authority forms. Instead, the data utilized all the forms provided by the resources as access points. Specifically, field of activity(subject) and title information on authorship were used to distinguish between persons who have the same name. The result showed that the system improved the performance of the information retrieval. The system has been also expected to be utilized over other metadata provided by libraries, in addition to the institutional repositories, in order to provide better quality information.

• The KIPS Transactions:PartC
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• v.11C no.5
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• pp.671-676
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• 2004

In this paper, we propose ultra-fast multimedia optical subscriber access network using optical frequency domain CDMA method in order to access the multimedia with multiple data rates. We numerically analyze the effects of spectral power distortion in the light source for the optical CDMA system modified PN codes and FBG(Fiber Bragg Grating)s. In the proposed multiple-rate multimedia access optical networks, the performances such as BER(Bit Error Rate) are the same for all data regardless of data rates in the case of the same number of simultaneous ONU. In the proposed ultra-fast multimedia optical subscriber access network, the performances for all data are much more improved than those in the conventional system.