• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.10a
• /
• pp.313-315
• /
• 2013

Hand-held devices such as smart phones exploit flash memory based storages to store data for processing jobs. Since the flash memory, non-volatile memory, is able to store mass data, it is required to use the index for processing queries. However, the flash memory has the shortcomings that it does not support the overwrite operation and its write operation is very slow. In this paper, we build the fixed grid file, one of the multi-dimensional spatial index, on a flash memory and evaluate the performance test.

• Journal of Hydrogen and New Energy
• /
• v.27 no.1
• /
• pp.22-28
• /
• 2016

It is necessary to store and supply hydrogen isotopes for Tokamak operation. A storage and delivery system (SDS) is used for storing hydrogen isotopes as a metal hydride form. We designed and fabricated a depleted uranium (DU) bed to store hydrogen isotopes. The rapid storage of hydrogen isotopes is very important not only for safety reasons but also for the economic design and operation of the SDS. The delivery rate at the desorption temperatures without the operation of a dry pump was analyzed in comparison with that with the operation of the dry pump. The effect of the initial desorption temperatures on the dehydriding of the DU without the operation of the dry pump was measured. The effect of the initial desorption temperatures on the dehydriding of DU with the operation of the dry pump was also measured and analyzed. The primary pressure on the desorption temperatures without the operation of the dry pump was analyzed in comparison with that with the operation of the dry pump. The temperature gradient of the coil heater and the primary vessel was also analyzed. Our results will be used to develop pilot scale hydrogen isotope processes. It was confirmed that dehydriding of a medium-scale DU bed has enabled without the operation of the dry pump.

• Nuclear Engineering and Technology
• /
• v.43 no.6
• /
• pp.531-546
• /
• 2011

The backward differentiation formula (BDF) method is applied to a three-dimensional reactor kinetics calculation for efficient yet accurate transient analysis with adaptive time step control. The coarse mesh finite difference (CMFD) formulation is used for an efficient implementation of the BDF method that does not require excessive memory to store old information from previous time steps. An iterative scheme to update the nodal coupling coefficients through higher order local nodal solutions is established in order to make it possible to store only node average fluxes of the previous five time points. An adaptive time step control method is derived using two order solutions, the fifth and the fourth order BDF solutions, which provide an estimate of the solution error at the current time point. The performance of the BDF- and CMFD-based spatial kinetics calculation and the adaptive time step control scheme is examined with the NEACRP control rod ejection and rod withdrawal benchmark problems. The accuracy is first assessed by comparing the BDF-based results with those of the Crank-Nicholson method with an exponential transform. The effectiveness of the adaptive time step control is then assessed in terms of the possible computing time reduction in producing sufficiently accurate solutions that meet the desired solution fidelity.

• Journal of Korea Multimedia Society
• /
• v.10 no.2
• /
• pp.170-178
• /
• 2007

In restricted resources based on mobile environment, we can use an embedded database technology for management of MPEG-7 data. At this time, some XML clustering methods can be used. But, to improve the performance efficiency better, a new clustering method is need to store effective MPEG-7 document. In this paper, we have designed and implemented a MPEG-7 document management system to store MPEG-7 document effectively in mobile device such as PDA. The system used the 버클리 DB XML as a native embedded XML database system based on the clustering method of MPEG-7 data.

• Journal of the Korea Convergence Society
• /
• v.12 no.7
• /
• pp.1-6
• /
• 2021

Currently, virus infection such as Corona 19 has become commonplace, and interest in unmanned systems is increasing in the field for non-face-to-face ICT services. In this paper, the function and performance of remotely successfully controlling a store through video and audio using an IP PBX with a broadcasting function was verified through a test. And the fully unmanned system is not gaining credibility due to various technical problems, however the central control system is a very efficient and reliable system because the controller can directly control the customer while monitoring the access and the inside of the store through the video and audio. In the future, we plan to study a completely unmanned remote control system using A.I technology.

• International Journal of Internet, Broadcasting and Communication
• /
• v.14 no.4
• /
• pp.121-131
• /
• 2022

We look at the initial stage of Meta (previous Facebook)'s new metaverse platform and investigate its platform design in pre-launch and ignition life stage. From the Rocket Model (RM)'s theoretical logic, the results reveal that Meta firstly focuses on investing in key content developers by acquiring virtual reality (VR), video, music content firms and offering production support platform of the augmented reality (AR) content, 'Spark AR' last three years (2019~2021) for attracting high-potential developers and users. In terms of three matching criteria, Meta develops an Artificial Intelligence (AI) powered translation software, partners with Microsoft (MS) for cloud computing and AI, and develops an AI platform for realistic avatar, MyoSuite. In 'connect' function, Meta curates the game concept submitted by game developers, welcomes other game and SNS based metaverse apps, and expands Horizon Worlds (HW) on VR devices to PCs and mobile devices. In 'transact' function, Meta offers 'HW Creator Funding' program for metaverse, launches the first commercialized Meta Avatar Store on Meta's conventional SNS and Messaging apps by inviting all fashion creators to design and sell clothing in this store. Mata also launches an initial test of non-fungible token (NFT) display on Instagram and expands it to Facebook in the US. Lastly, regarding optimization, especially in the face of recent data privacy issues that have adversely affected corporate key performance indicators (KPIs), Meta assures not to collect any new data and to make its privacy policy easier to understand and update its terms of service more user friendly.

• International Journal of Computer Science & Network Security
• /
• v.24 no.9
• /
• pp.150-156
• /
• 2024

With the advent of personalized search engines, a myriad of approaches came into practice. With social media emergence the personalization was extended to different level. The main reason for this preference of personalized engine over traditional search was need of accurate and precise results. Due to paucity of time and patience users didn't want to surf several pages to find the result that suits them most. Personalized search engines could solve this problem effectively by understanding user through profiles and histories and thus diminishing uncertainty and ambiguity. But since several layers of personalization were added to basic search, the response time and resource requirement (for profile storage) increased manifold. So it's time to focus on optimizing the layered architectures of personalization. The paper presents a layout of the multi agent based personalized search engine that works on histories and profiles. Further to store the huge amount of data, distributed database is used at its core, so high availability, scaling, and geographic distribution are built in and easy to use. Initially results are retrieved using traditional search engine, after applying layer of personalization the results are provided to user. MongoDB is used to store profiles in flexible form thus improving the performance of the engine. Further Weighted Sum model is used to rank the pages in personalization layer.

• Journal of Aerospace System Engineering
• /
• v.18 no.4
• /
• pp.89-95
• /
• 2024

This paper introduces an effective and convenient method for utilizing onboard memory space to process remote commands, telemetry, and interplanetary network protocol data in satellite onboard systems. By enhancing the doubly linked list data structure to store and make accessible variable-length communication protocol data either sequentially or at variable locations, the paper enhances memory capacity utilization. The concept of 'grape' is introduced into the doubly linked list data structure to manage variable-length data and its access, with performance verification conducted through its reference implementation. This novel approach to linked lists is termed 'grape.'

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.1
• /
• pp.135-142
• /
• 2013

This study is intended for bedding stores and finds management performance factors from providers' aspect. Henceforth this study can be used when bedding stores were considered to establish by determinations and bedding companies with statistics as a criterion and a tool so that make an accurate estimate. First, it was found that location and trade area are the most influential factor in the management performance. Second, the result of study showed that location placed first in the importance of management performance factors in bedding stores, consumer came second, followed by competition. Third, it was assumed that the large floating population around the bedding store was the most important variable in location factor, the large resident population was the most important one in the consumer factor and high quality product was the most important one in the economic factor.

• Journal of the Korean Society of Food Culture
• /
• v.19 no.1
• /
• pp.1-11
• /
• 2004

The specific purposes of this study are that ; 1) to investigate the distinguished selection attributes on performance of Japanese chain restaurant according to general characteristics of the respondent ; 2) to find out relationships between selection attributes on performance for Japanese restaurant and customer's satisfaction Frequency analysis. one-way ANOVA, reliability analysis, factor analysis, multiple regression were used to analyze the data. Total 350 questionnaires were distributed and 312 were replied(89.14%). Selection attributes on performance for Japanese chain restaurant was divided into 7 factors. There are Factor1 'Store Image & Kindness', Factor2 'Sanitation & Taste', Factor3 'Approximation & Children's Menu', Factor4 'Delivery & Business Hours', Factor5 'Food Quantity & Korean Food', Factor6 'Service & Parking' Factor7 'Price & Publicity'. Monthly income, eating-out expense per once and type of companion have significant influences on selection attributes for performance. Customer's total satisfaction is significantly affected by selection attributes on performance. Factor7 'Price & Publicity' has the most significant influence on customer's satisfaction. We expect that the results can be used to provide basic information to plan marketing strategies, and take improved customer's satisfaction for Japanese chain restaurants.