• Journal of Digital Convergence
• /
• v.11 no.10
• /
• pp.379-385
• /
• 2013

MANET is not suitable to be applied to vehicle environments because of frequent path loss and path re-routing. To solve these problem, It is known that location-based routing protocol VANET is efficient. But, the VANET algorithm does not consider urban environments due to frequent vehicle movement and jamming by tall building. In this paper, we propose an efficient routing protocol to improve transfer efficiency and reduce transfer hop count. in urban networks.

• Journal of Digital Convergence
• /
• v.15 no.2
• /
• pp.369-374
• /
• 2017

The object of this study is to offer domestic and overseas travel informations efficiently for domestic tourists growing far beyond 15 million even now through user centered interface more convenient and accurate. In a method of research, 100 people were surveyed after recasting of evaluation questionnaire about UI design using 5-point Likert and nominal scale and additionally, the in-depth interviews were given to 10 people who use travel application frequently. In consequence, this interview revealed where users feel convenience and difficulty and want improvement of usability, information accuracy, etc. Finally, this study has a meaning to suggest new UI prototypes and various guideline about additional UI design on the basis of surveyed parts.

• Journal of Digital Convergence
• /
• v.17 no.12
• /
• pp.219-228
• /
• 2019

Thanks to the development of information technology and the vitalization of smart services, the Internet of Things (IoT) technology, in which various smart devices are connected to the network, has been continuously developed. In the legacy IoT architecture, data processing has been centralized based on cloud computing, but there are concerns about a single point of failure, end-to-end transmission delay, and security. To solve these problems, it is necessary to apply decentralized blockchain technology to the IoT. However, it is hard for the IoT devices with limited computing power to mine blocks, which consumes a great amount of computing resources. To overcome this difficulty, this paper proposes an IoT architecture based on the edge computing technology that can apply blockchain technology to IoT devices, which lack computing resources. This paper also presents an operaional procedure of blockchain in the edge computing-based IoT architecture.

• Journal of Information Technology and Architecture
• /
• v.10 no.4
• /
• pp.509-516
• /
• 2013

Cloud services are recognized the essential IT infrastructure in the optimal smart society which is changing rapidly as a low-cost and high-efficiency. This service of starting from prominent overseas companies such as Google, Amazon, had influenced on the introduction of the service for the various policies of foreign governments, including the United States and the United Kingdom. Such countries adopting to the cloud computing and make transform to the cloud service of existing public service for the effective management of information resources. In this study, we have proposed the main determining factors of cloud adoption, the model of cloud governance for the adoption of public cloud service.

• The KIPS Transactions:PartD
• /
• v.14D no.7
• /
• pp.719-726
• /
• 2007

Recently, NAND flash memory has been used for a storage device in various mobile computing devices such as MP3 players, mobile phones and laptops because of its shock-resistant, low-power consumption, and none-volatile properties. However, due to the very distinct characteristics of flash memory, disk based systems and applications may result in severe performance degradation when directly adopting them on flash memory storage systems. Especially, when a B-tree is constructed, intensive overwrite operations may be caused by record inserting, deleting, and its reorganizing, This could result in severe performance degradation on NAND flash memory. In this paper, we propose an efficient buffer management scheme, called IBSF, which eliminates redundant index units in the index buffer and then delays the time that the index buffer is filled up. Consequently, IBSF significantly reduces the number of write operations to a flash memory when constructing a B-tree. We also show that IBSF yields a better performance on a flash memory by comparing it to the related technique called BFTL through various experiments.

• Journal of the Korean association of regional geographers
• /
• v.14 no.2
• /
• pp.159-172
• /
• 2008

The purpose of this study is to analyse the content of regional learning in social studies textbooks for the 1st-year and 3rd-year middles school. The content of regional learning in social studies for middle school is described with not layered scale between local and global but segmented scale. So this study selected Andong city as an exemplary case and reconstructed the learning content and class to things necessary in the age of globalization. In the class for designing the local image of Andong, the students were advised to visit the homepage in Andong city. In the course. students showed increasing interest in local festivals, events, locality promotion, etc. executed by Andong. Many of the students were interested in activity designing new local images of Andong. In particular, According to the result of applying localization learning necessary in the age of globalization to 1st-year middle school students, the class was found to be understood adequately. It is needed to develop localization teaching-learning programs fit for the developmental stage of 1st-year middle school students.

• Journal of Navigation and Port Research
• /
• v.39 no.6
• /
• pp.515-521
• /
• 2015

The purpose of this study was to analyze the weights of obstacle factors against mutual access of towed trailers of car-ferry between South Korea and China using Fuzzy-AHP. To this end, factors were first selected through literature research and finally selected through in-depth interviews with a group of experts in cargoes who are currently in car-ferry companies. Selected high rank obstacle factors included unstable service provision, limited policy support, and additional costs being incurred and among them, unstable service provision was identified as the most serious obstacle factor through analysis. Eleven measurement variables selected include insufficient supply of container yard, trailer insurance and management issues, insufficient special equipment, insufficient specialized manpower, limited input service courses, insufficient marketing and public relations strategies, and increasing transportation costs and among them, increasing equipment returning costs due to unbalanced cargo gathering were identified as the most serious obstacle factor through analysis followed by limited input service courses, insufficient special equipment, delays in procedures, and occurrence of additional procedures in order of precedence.

• Journal of KIISE:Databases
• /
• v.29 no.2
• /
• pp.119-127
• /
• 2002

Video server which stores video streams should serve more users with the requested streams rapidly, satisfying their time constraints. However, the number of users supported and the response times for the requested services in video server are in the oppositional relationship with viewpoint of disk throughput. In this paper, we propose new policy that can provide not only rapid responses for the service requests but also increase the number of users supported in the storage system of video server. The policy admits the random movements of disk heads for urgent service requests but maintains the sequential or restricted movements of disk heads and eliminates rewind time of disk heads for less-urgent service requests in storage system of multiple disks environment so that it can not satisfy only the QoS of users but also support more users.

• The KIPS Transactions:PartA
• /
• v.8A no.4
• /
• pp.287-292
• /
• 2001

Multimedia service systems should have efficient capacity to serve the growing clients and new data. In the general streaming services, users can endure the small amount of time delay at the beginning of service. But they want to have good quality of service. A streaming server tries to transfer video files to clients from a repository of files in real time. The server must guarantee concurrent and uninterrupted delivery of each video stream requested from clients. To achieve its purpose, many stream servers adopt multi-processors, sufficient memory, and RAID or SAN in their systems. In this paper, we propose a Linux-based parallel media streaming server. It is superior to the other systems in the storing structure, fault-tolerance, and service capacity. Since this system supports the web interlace, users can operate easily through the www. This system uses unique striping policy to distribute multimedia files into the parallel storage nodes. If a service request occurs, each storage node transmits striped files concurrently to the client. Its performance is better than the single media streaming service because of the parallel architecture.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.22 no.3
• /
• pp.129-150
• /
• 2011

The study aims at discussing issues concerning the establishment of the cooperative repository libraries based on regional central libraries which not only support various types of regional libraries and conduct cooperative businesses with them, but also are responsible for collecting and preserving library materials. The study analyzes concepts and types of cooperative repository libraries by literature review and explores cooperative repository libraries in the United States. Futhermore, it conducts a survey and finds that the regional central libraries do not perform their preservation functions, due to the lack of their manpower and budget. As a result, the study provides an establishment plan for cooperative repository libraries which participant libraries hold ownership of transferred materials and regional central libraries own the right of management. Also, it suggests to expand cooperative repository libraries' service coverage from participants to regional communities.