• Title/Summary/Keyword: Computer Studies

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MediaCloud: A New Paradigm of Multimedia Computing

  • Hui, Wen;Lin, Chuang;Yang, Yang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.4
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    • pp.1153-1170
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    • 2012
  • Multimedia computing has attracted considerable attention with the rapid growth in the development and application of multimedia technology. Current studies have attempted to support the increasing resource consumption and computational overhead caused by multimedia computing. In this paper, we propose $MediaCloud$, a new multimedia computing paradigm that integrates the concept of cloud computing in handling multimedia applications and services effectively and efficiently. $MediaCloud$ faces the following key challenges: heterogeneity, scalability, and multimedia Quality of Service (QoS) provisioning. To address the challenges above, first, a layered architecture of $MediaCloud$, which can provide scalable multimedia services, is presented. Then, $MediaCloud$ technologies by which users can access multimedia services from different terminals anytime and anywhere with QoS provisioning are introduced. Finally, $MediaCloud$ implementation and applications are presented, and media retrieval and delivery are adopted as case studies to demonstrate the feasibility of the proposed $MediaCloud$ design.

A Novel Feature Selection Method in the Categorization of Imbalanced Textual Data

  • Pouramini, Jafar;Minaei-Bidgoli, Behrouze;Esmaeili, Mahdi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.8
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    • pp.3725-3748
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    • 2018
  • Text data distribution is often imbalanced. Imbalanced data is one of the challenges in text classification, as it leads to the loss of performance of classifiers. Many studies have been conducted so far in this regard. The proposed solutions are divided into several general categories, include sampling-based and algorithm-based methods. In recent studies, feature selection has also been considered as one of the solutions for the imbalance problem. In this paper, a novel one-sided feature selection known as probabilistic feature selection (PFS) was presented for imbalanced text classification. The PFS is a probabilistic method that is calculated using feature distribution. Compared to the similar methods, the PFS has more parameters. In order to evaluate the performance of the proposed method, the feature selection methods including Gini, MI, FAST and DFS were implemented. To assess the proposed method, the decision tree classifications such as C4.5 and Naive Bayes were used. The results of tests on Reuters-21875 and WebKB figures per F-measure suggested that the proposed feature selection has significantly improved the performance of the classifiers.

Content Adaptive Watermarkding Using a Stochastic Visual Model Based on Multiwavelet Transform

  • Kwon, Ki-Ryong;Kang, Kyun-Ho;Kwon, Seong-Geun;Moon, Kwang-Seok;Lee, Joon-Jae
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1511-1514
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    • 2002
  • This paper presents content adaptive image watermark embedding using stochastic visual model based on multiwavelet transform. To embedding watermark, the original image is decomposed into 4 levels using a discrete multiwavelet transform, then a watermark is embedded into the JND(just noticeable differences) of the image each subband. The perceptual model is applied with a stochastic approach fer watermark embedding. This is based on the computation of a NVF(noise visibility function) that have local image properties. The perceptual model with content adaptive watermarking algorithm embed at the texture and edge region for more strongly embedded watermark by the JND. This method uses stationary Generalized Gaussian model characteristic because watermark has noise properties. The experiment results of simulation of the proposed watermark embedding method using stochastic visual model based on multiwavelet transform techniques was found to be excellent invisibility and robustness.

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Recent advances in dental implants

  • Hong, Do Gia Khang;Oh, Ji-hyeon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.39
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    • pp.33.1-33.10
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    • 2017
  • Dental implants are a common treatment for the loss of teeth. This paper summarizes current knowledge on implant surfaces, immediate loading versus conventional loading, short implants, sinus lifting, and custom implants using three-dimensional printing. Most of the implant surface modifications showed good osseointegration results. Regarding biomolecular coatings, which have been recently developed and studied, good results were observed in animal experiments. Immediate loading had similar clinical outcomes compared to conventional loading and can be used as a successful treatment because it has the advantage of reducing treatment times and providing early function and aesthetics. Short implants showed similar clinical outcomes compared to standard implants. A variety of sinus augmentation techniques, grafting materials, and alternative techniques, such as tilted implants, zygomatic implants, and short implants, can be used. With the development of new technologies in three-dimension and computer-aided design/computer-aided manufacturing (CAD/CAM) customized implants can be used as an alternative to conventional implant designs. However, there are limitations due to the lack of long-term studies or clinical studies. A long-term clinical trial and a more predictive study are needed.

A Consideration of the Optimal Thinning Algorithm For Contour Line Vectorizing in the Geographic Information System (지리정보시스템에서 등고선 벡터화를 위한 최적 세선화 알고리즘에 대한 고찰)

  • Won, Nam-Sik;Jeon, Il-Soo;Lee, Doo-Han;Bu, Ki-Dong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.2 no.1
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    • pp.45-53
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    • 1999
  • Geographic Information System(GIS) which facilitates efficient storage and retrieval of geographic information is very useful tools. It is of extreme importance to develop automated vectorizing system as input method for GIS, because it takes a large amount of time and effort in constructing a GIS. In all kinds of map processed by GIS, contour line map specially takes a large amount of effort. In this paper we have considered an optimal thinning algorithm for the contour line vectorizing in the GIS. Based on the experimental results, it has been proved that thinning algorithm using the connection value is most excellent algorithm in the similarity and connectivity.

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A Study on Structuring Method of Study Data Supporting Efficient Keyword Search (효율적인 키워드 검색을 지원하는 학습자료의 구조화 방법 연구)

  • Kim, Eun-Kyung;Choi, Jin-Oh
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.1063-1066
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    • 2005
  • Most reading systems that supply various study data generally support keyword search. But the usual keyword matching techniques have a problem to require the exact keyword matching, and could not find similar field materials. Futhermore, testing materials have too little information to apply the keyword matching search. To solve these problems, this thesis proposes the method to extract the important keyword from study data and to construct the database automatically when the data are stored at the storage. And using prepared similar terminology database, we suggest the intelligent and efficient technique to find study materials.

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Space-Stretch Tradeoff Optimization for Routing in Internet-Like Graphs

  • Tang, Mingdong;Zhang, Guoqiang;Liu, Jianxun
    • Journal of Communications and Networks
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    • v.14 no.5
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    • pp.546-553
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    • 2012
  • Compact routing intends to achieve good tradeoff between the routing path length and the memory overhead, and is recently considered as a main alternative to overcome the fundamental scaling problems of the Internet routing system. Plenty of studies have been conducted on compact routing, and quite a few universal compact routing schemes have been designed for arbitrary network topologies. However, it is generally believed that specialized compact routing schemes for peculiar network topologies can have better performance than universal ones. Studies on complex networks have uncovered that most real-world networks exhibit power-law degree distributions, i.e., a few nodes have very high degrees while many other nodes have low degrees. High-degree nodes play the crucial role of hubs in communication and inter-networking. Based on this fact, we propose two highest-degree landmark based compact routing schemes, namely HDLR and $HDLR^+$. Theoretical analysis on random power-law graphs shows that the two schemes can achieve better space-stretch trade-offs than previous compact routing schemes. Simulations conducted on random power-law graphs and real-world AS-level Internet graph validate the effectiveness of our schemes.

Leader Decision Protocol for Dynamic Changing Topology in Mobile Ad hoc Networks (모바일 ad hoc 네트워크에서 동적인 토폴로지 변화에 따른 리더 결정)

  • Kim, Young-Lan;Han, Hyun-Goo;Park, Sung-Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.11
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    • pp.4543-4552
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    • 2010
  • A leader is a special process who roles as the coordinator within multiple processes of a group. In a distributed system, leader election is the procedure of electing a coordinator. This is a very important issue for building fault-tolerant distributed systems. When two normal mobile ad hoc networks are merged, there are two leaders. This violates the safety property, so a mechanism to detect and handle are required. In mobile ad hoc distributed computing system, we propose a leader competition protocol and to prove the temporal logic to it. This solution is based on the group membership detection algorithm.

Attention Deep Neural Networks Learning based on Multiple Loss functions for Video Face Recognition (비디오 얼굴인식을 위한 다중 손실 함수 기반 어텐션 심층신경망 학습 제안)

  • Kim, Kyeong Tae;You, Wonsang;Choi, Jae Young
    • Journal of Korea Multimedia Society
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    • v.24 no.10
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    • pp.1380-1390
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    • 2021
  • The video face recognition (FR) is one of the most popular researches in the field of computer vision due to a variety of applications. In particular, research using the attention mechanism is being actively conducted. In video face recognition, attention represents where to focus on by using the input value of the whole or a specific region, or which frame to focus on when there are many frames. In this paper, we propose a novel attention based deep learning method. Main novelties of our method are (1) the use of combining two loss functions, namely weighted Softmax loss function and a Triplet loss function and (2) the feasibility of end-to-end learning which includes the feature embedding network and attention weight computation. The feature embedding network has a positive effect on the attention weight computation by using combined loss function and end-to-end learning. To demonstrate the effectiveness of our proposed method, extensive and comparative experiments have been carried out to evaluate our method on IJB-A dataset with their standard evaluation protocols. Our proposed method represented better or comparable recognition rate compared to other state-of-the-art video FR methods.

Cybercrime as a Discourse of Interpretations: the Semantics of Speech Silence vs Psychological Motivation for Actual Trouble

  • Matveev, Vitaliy;Eduardivna, Nykytchenko Olena;Stefanova, Nataliia;Khrypko, Svitlana;Ishchuk, Alla;PASKO, Katerina
    • International Journal of Computer Science & Network Security
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    • v.21 no.8
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    • pp.203-211
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    • 2021
  • The article studies the discourse and a legal uncertainty of the popular and generally understandable concept of cybercrime. The authors reveal the doctrinal approaches to the definition of cybercrime, cyberspace, computer crime. The analysis of international legal acts and legislation of Ukraine in fighting cybercrime is carried out. The conclusion is made about the need to improve national legislation and establish international cooperation to develop the tools for countering cybercrime and minimizing its negative outcomes. The phenomenon of nicknames is studied as a semantic source, which potentially generates a number of threats and troubles - the crisis of traditional anthroponymic culture, identity crisis, hidden sociality, and indefinite institutionalization, incognito style, a range of manifestations of loneliness - from voluntary solitude to traumatic isolation and forced detachment. The core idea is that it is the phenomenon of incognito and hidden name (nickname and other alternatives) that is the motivational stimulus for the fact of information trouble or crime.