• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.42-53
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• 2020

With the development of social network services, graph structures have been utilized to represent relationships among objects in various applications. Recently, a demand of subgraph matching in real-time graph streams has been increased. Therefore, an efficient approximate Top-k subgraph matching scheme for low latency in real-time graph streams is required. In this paper, we propose an approximate Top-k subgraph matching scheme considering data reuse in graph stream environments. The proposed scheme utilizes the distributed stream processing platform, called Storm to handle a large amount of stream data. We also utilize an existing data reuse scheme to decrease stream processing costs. We propose a distance based summary indexing technique to generate Top-k subgraph matching results. The proposed summary indexing technique costs very low since it only stores distances among vertices that are selected in advance. Finally, we provide k subgraph matching results to users by performing an approximate Top-k matching on the summary indexing. In order to show the superiority of the proposed scheme, we conduct various performance evaluations in diverse real world datasets.

• Journal of Korean Association for Spatial Structures
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• v.10 no.3
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• pp.49-56
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• 2010

In this study, the control performance of a smart top-story isolation system for tall buildings subjected to wind excitation was investigated. To this end, a 77-story tall building structure was employed and wind loads obtained from wind tunnel test were used for numerical simulations. The top-story of an example structure is separated from the main structure by a smart base isolation system composed of friction pendulum systems (FPS) and MR dampers. The primary purpose of the smart top-story isolation system is to mitigate the dynamic responses of the main structure, but the excessive movement of the isolated top story may cause the unstableness of the building structure. Therefore, the skyhook control algorithm was used to effectively reduce both responses of the isolated top story and the main structure. The control performance of the proposed smart top-story isolation system was investigated in comparison with that of the passive top-story isolation system. It has been shown from numerical simulation results that the smart top-story isolation system can effectively reduce wind-induced responses of the example building structure compared to the passive top-story isolation system with reduction of the top-story movement.

• Journal of KIISE:Databases
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• v.36 no.3
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• pp.189-197
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• 2009

Top-k queries are important to many wireless sensor applications. Conventional Top-k query processing algorithms install a filter at each sensor node and suppress unnecessary sensor updates. However, they have some drawbacks that the sensor nodes consume energy extremely to probe sensor reading or update filters. Especially, it becomes worse, when the variation ratio of top-k result is higher. In this paper, we propose a novel Top-k query processing algorithm for energy-efficiency. First, each sensor determines its priority as the order of data gathering. Next, sensor nodes that have higher priority transmit their sensor readings to the base station until gathering k sensor readings. In order to show the superiority of our query processing algorithm, we simulate the performance with the existing query processing algorithms. As a result, our experimental results show that the network lifetime of our method is prolonged largely over the existing method.

• Smart Media Journal
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• v.9 no.4
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• pp.162-169
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• 2020

Design is a key factor that determines the competitiveness of products in the textile and fashion industry. It is very important to measure the similarity of the proposed design in order to prevent unauthorized copying and to confirm the originality. In this study, a deep learning technique was used to quantify features from images of textile designs, and similarity was measured using Spearman correlation coefficients. To verify that similar samples were actually detected, 300 images were randomly rotated and color changed. The results of Top-3 and Top-5 in the order of similarity value were measured to see if samples that rotated or changed color were detected. As a result, the VGG-16 model recorded significantly higher performance than did AlexNet. The performance of the VGG-16 model was the highest at 64% and 73.67% in the Top-3 and Top-5, where similarity results were high in the case of the rotated image. appear. In the case of color change, the highest in Top-3 and Top-5 at 86.33% and 90%, respectively.

• Journal of KIISE:Databases
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• v.41 no.4
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• pp.256-261
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• 2014

The problem of top-${\kappa}$ set similarity joins finds the top-${\kappa}$ pairs of records ranked by their similarities between two sets of input records. We propose an efficient algorithm to return top-${\kappa}$ similarity join pairs using a sampling technique. From a sample of the input records, we construct a histogram of set similarity joins, and then compute an estimated similarity threshold in the histogram for top-${\kappa}$ join pairs within the error bound of 95% confidence level based on statistical inference. Finally, the estimated threshold is applied to the traditional similarity join algorithm which uses the min-heap structure to get top-${\kappa}$ similarity joins. The experimental results show the good performance of the proposed algorithm on large real datasets.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.12
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• pp.543-548
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• 2015

Recently top-k query processing has been extremely important along with the explosion of data produced by a variety of applications. Top-k queries return the best k results ordered by a user-provided monotone scoring function. As cloud computing service has been getting more popular than ever, a hot attention has been paid to cloud-based data outsourcing in which clients' data are stored and managed by the cloud. The cloud-based data outsourcing, though, exposes a critical secuity concern of sensitive data, resulting in the misuse of unauthorized users. Hence it is essential to encrypt sensitive data before outsourcing the data to the cloud. However, there has been little attention to efficient top-k processing on the encrypted cloud data. In this paper we propose a novel top-k processing algorithm that can efficiently process a large amount of encrypted data in the cloud. The main idea of the algorithm is to prune unpromising intermediate results at the early phase without decrypting the encrypted data by leveraging an order-preserving encrypted technique. Experiment results show that the proposed top-k processing algorithm significantly reduces the overhead of client systems from 10X to 10000X.

• KIISE Transactions on Computing Practices
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• v.21 no.1
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• pp.76-81
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• 2015

Research on top-k query processing algorithms for analyzing big data have been spotlighted recently. However, because existing top-k query processing algorithms do not provide an efficient index structure, they incur high query processing costs and cannot support various types of queries. To solve these problems, we propose a top-k query processing algorithm using a view selection method based on a grid index. The proposed algorithm reduces the query processing time by retrieving the minimum number of grid cells for the query range, by using a grid index-based view selection method. Finally, we show from our performance analysis that the proposed scheme outperforms an existing scheme, in terms of both query processing time and query result accuracy.

• Journal of the Korean GEO-environmental Society
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• v.23 no.12
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• pp.17-23
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• 2022

This paper analyze the precast panel retaining wall's safety factor changes based on the numerical analysis using PLAXIS 2D software. Numerical analysis conditions include construction method, nail and panel fixing method, backfill material compaction conditions, rainfall conditions. The classification according to the construction method of the precast panel retaining wall includes the top-down and bottom-up methods. The difference between the top-down and bottom-up methods is the presence or absence backfill material and the ground excavation method. The top-down method involves vertically excavating the ground and attaching the panel using mortar, but in the bottom-up method, the ground is vertically excavated and harden the backfill material. As a result of numerical analysis, the top-down method secured a higher safety factor in all cases except the rainfall conditions.

• Asia-Pacific Journal of Business
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• v.12 no.3
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• pp.251-269
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• 2021

Purpose & methodology - This study is to answer the following three questions, analyzing data on Top 50 Indian Billionaires, Top 50 Indian companies and Top 50 Indian start-ups. The first is whether or not traiditonal merchant caste like Vaisya's ability of creating wealth declined as some studies argue. The second is whether non-merchant caste like Brahmin, Kshatriya, OBC, Dalit, emerged as an India's new business elite. The third is whether the results of top 50 Indian companies and top 50 start-ups' analyses have similarities with that of top 50 Indian Billionaires analysis. Findings - The result is firstly, the ability of creating wealth of businessmen from the merchant caste was still overwhelming. Secondly, the big businessmen' rising from non-merchant castes as a new business elite was extremely rare. Thirdly, according to the analysis of top 50 Indian start-ups, the percentage of Vaisya has significantly declined while the the percentage of upper castes like Brahmin has noticeably increased. Fourthly, no evidence was found that businessmen from the lower castes like OBC or Dalit were increasing the expanding business influence. Research implications - The Studies mean that in big-sized Indian companies, the power of traditional merchant caste remains the same as before and is even reinforcing, while in small start-ups, Vaisya's power is considerably decreasing, and the upper castes like Brahmin who are highly educated are noticeably increasing.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.1
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• pp.123-130
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• 2012

The purpose of this study is to understand Skull Images in fashion trends and Skull Image Top Design for Female Teenagers. The methods of this study are an academic literature review as well as practical study through actual case studies about. The subjects of the study were 53 Female Teenagers who lived in Chuncheon. Data were collected during March, 2009. Statistical analyses used in the study were frequency. An adolescent period, they are rebellious, sensual and syntonic inclination. These days, Lots of Female Teenagers want unique fashion for herself and select Skull Image clothing. But they want fit and pretty style not big-look. In this study, I designed seven pieces of Top blouse while applying Skull Image, an important image of Hip-hop and Punk fashion, and the concepts of the continuance theory to them. This study will make a contribution to the designing of Top for Female Teenagers through reinterpretation of the Hip-hop and Punk fashion. In addition, there are practicable and unique Top design for Female Teenagers.