A multi-tier ensemble construction of classifiers for phishing email detection and filtering
- Authors: Abawajy, Jemal , Kelarev, Andrei
- Date: 2012
- Type: Text , Conference paper
- Relation: 4th International Symposium on Cyberspace Safety and Security, CSS 2012 Vol. 7672 LNCS, p. 48-56
- Full Text: false
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- Description: This paper is devoted to multi-tier ensemble classifiers for the detection and filtering of phishing emails. We introduce a new construction of ensemble classifiers, based on the well known and productive multi-tier approach. Our experiments evaluate their performance for the detection and filtering of phishing emails. The multi-tier constructions are well known and have been used to design effective classifiers for email classification and other applications previously. We investigate new multi-tier ensemble classifiers, where diverse ensemble methods are combined in a unified system by incorporating different ensembles at a lower tier as an integral part of another ensemble at the top tier. Our novel contribution is to investigate the possibility and effectiveness of combining diverse ensemble methods into one large multi-tier ensemble for the example of detection and filtering of phishing emails. Our study handled a few essential ensemble methods and more recent approaches incorporated into a combined multi-tier ensemble classifier. The results show that new large multi-tier ensemble classifiers achieved better performance compared with the outcomes of the base classifiers and ensemble classifiers incorporated in the multi-tier system. This demonstrates that the new method of combining diverse ensembles into one unified multi-tier ensemble can be applied to increase the performance of classifiers if diverse ensembles are incorporated in the system. © 2012 Springer-Verlag.
- Description: 2003010675
The discrete gradient evolutionary strategy method for global optimization
- Authors: Abbas, Hussein , Bagirov, Adil , Zhang, Jiapu
- Date: 2003
- Type: Text , Conference paper
- Relation: Paper presented at the Congress on Evolutionary Computation CEC 2003, Canberra : 8th December, 2003
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- Description: Global optimization problems continue to be a challenge in computational mathematics. The field is progressing in two streams: deterministic and heuristic approaches. In this paper, we present a hybrid method that uses the discrete gradient method, which is a derivative free local search method, and evolutionary strategies. We show that the hybridization of the two methods is better than each of them in isolation.
- Description: E1
- Description: 2003000440
Variations in accounting students' conceptions of learning
- Authors: Abhayawansa, Subhash , Bowden, Mark , Pillay, Soma
- Date: 2013
- Type: Text , Conference paper
- Relation: The Scholarship of Teaching and Learning, RMIT Accounting Educators Conference 2013, Melbourne, Australia, 18th November 2013 p. 1-30
- Full Text: false
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- Description: Students’ conceptions of learning or preconceived views of what learning means to students have been found to play a significant role in how they choose to approach their learning. This study investigates conceptions of learning held by accounting students in their second- and third-years in university. The study is based on phenomenographic and content-analytic approaches applied to survey responses of 207 accounting students from an Australian university. In the first phase of the analysis we identify 6 learning conceptions. Learning is conceived as: (1) increase of knowledge; (2) understanding; (3) knowledge acquisition for application; (4) a pathway to success; (5) seeing in new ways; and (6) self-development. Compared to similar studies we did not find evidence of the conception ‘learning as memorisation’. In contrast to prior research ‘learning as understanding’ emerged as a lower- order conception of learning in accounting students in this study. In the second phase we find that, after controlling for a range of factors that are likely to affect students’ conceptions of learning third-year students are more likely to adopt a higher-order conception. However, majority of the students, including third year students, continue to adopt low-order conceptions. These findings highlight the need to extend student learning beyond the acquisition of technical skills and knowledge to instil higher-order learning conceptions which underpin the development of generic skills much demanded of professional accountants. As a result, the findings of this study have implications for curriculum and assessment design, and learning and teaching practice in accounting degree programs.
Poster : Privacy protection for real world participatory sensing system
- Authors: Abrar, Nafeez , Iqbal, Anindya , Zaman, Shaolin , Murshed, Manzur
- Date: 2016
- Type: Text , Conference paper
- Relation: 14th Annual International Conference on Mobile Systems, Applications, and Services Companion
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- Description: Participatory Sensing System (PSS) is an emerging technology for collection of useful information as the use of smart-phones has been increasing lately among community people. It has a wide range of applications like environmental monitoring, product price sharing, health monitoring etc. But people have to share their location and other information which is a high privacy risk. Our main contribution of this work is to develop a technique for PSS which can provide privacy protection for the participants in manageable time in real world.
A review on chemical diagnosis techniques for transformer paper insulation degradation
- Authors: Abu Bakar, Norazhar , Abu Siada, Ahmed , Islam, Syed
- Date: 2013
- Type: Text , Conference proceedings , Conference paper
- Relation: 2013 Australasian Universities Power Engineering Conference, AUPEC 2013; Hobart, Australia; 29th September-3rd October 2013 p. 1-6
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- Description: Energized parts within power transformer are isolated using paper insulation and are immersed in insulating oil. Hence, transformer oil and paper insulation are essential sources to detect incipient and fast developing power transformer faults. Several chemical diagnoses techniques are developed to examine the condition of paper insulation such as degree of polymerization, carbon oxides, furanic compounds and methanol. The principle and limitation of these diagnoses are discussed and compared in this paper.
Image processing-based on-line technique to detect power transformer winding faults
- Authors: Abu-Siada, Ahmed , Islam, Syed
- Date: 2013
- Type: Text , Conference proceedings , Conference paper
- Relation: 39th Annual Conference of the IEEE Industrial Electronics Society, IECON 2013; Vienna, Austria; 10th-14th November 2013 p. 1-6
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- Description: Frequency Response Analysis (FRA) has been growing in popularity in recent times as a tool to detect mechanical deformation within power transformers. To conduct the test, the transformer has to be taken out of service which may cause interruption to the electricity grid. Moreover, because FRA relies on graphical analysis, it calls for an expert person to analyse the results as so far, there is no standard code for FRA interpretation worldwide. In this paper an online technique is introduced to detect the internal faults within a power transformer by constructing the voltage-current (V-I) locus diagram to provide a current state of the transformer health condition. The technique does not call for any special equipment as it uses the existing metering devices attached to any power transformer to monitor the input voltage, output voltage and the input current at the power frequency and hence online monitoring can be realised. Various types of faults have been simulated to assess its impact on the proposed locus. A Matlab code based on digital image processing is developed to calculate any deviation of the V-I locus with respect to the reference one and to identify the type of fault.
Ganking, corpse camping and ninja looting from the perception of the MMORPG community: Acceptable behaviour or unacceptable griefing?
- Authors: Achterbosch, Leigh , Miller, Charlynn , Vamplew, Peter
- Date: 2013
- Type: Text , Conference paper
- Relation: 9th Australasian Conference on Interactive entertainment p. 19
- Full Text: false
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- Description: Every day in online games designed to entertain, an unknown percentage of users are experiencing what is known as 'Griefing'. Griefing is used to describe when a player within a multiplayer online environment intentionally disrupts another player's game experience for his/her own personal enjoyment or material gain. Unrestrained, griefing could lead to a downward spiral of the number of people playing Massively Multiplayer Online Role-Playing Games (MMORPG)s, and possibly the death of smaller MMORPGs. Big game publishers may not wish to risk supporting the genre. There have been studies conducted in the past that attempt to define griefing and the different forms it takes in MMORPGs. These were outlined from the perception of the general player, and so did not examine differences in perception of griefing by different types of players. The authors conducted an online survey with the intention to discover the perception of various in-game actions previously identified in research as griefing, among griefers and griefing victims. In general players who identified themselves as griefers were more likely to regard these actions as a part of the game people had to learn to accept and not griefing. However some patterns of commonality were also observed between griefers and subjects of griefing, with some actions previously identified as griefing in the literature less commonly regarded as griefing by both player types in this survey.
Sticky behavior of whey protein isolate and lactose droplets during convective drying
- Authors: Adhikari, Benu , Howes, Tony , Shrestha, A. , Bhandari, Bhesh
- Date: 2006
- Type: Conference paper
- Relation: Paper presented at 2006 AIChE Spring National Meeting - 5th World Congress on Particle Technology, Orlando, Florida :
- Full Text: false
- Description: Stickiness of whey protein isolate (WPI) and spray dried lactose droplets was studied at two air temperatures (65±0.5°C, 80±0.5°C), 0.75 m/s air velocity and 2-2.5% relative humidity using an in situ stickiness testing device. A stainless steel probe with 50 mm/min contact/withdrawal speed was used. The moisture and temperature histories were measured through parallel experiments. In each case, the surface of the lactose droplet remained sticky and failed cohesively until the surface was completely surrounded with crystals. The crystal layer remained fragile, fractured upon the probe contact and a thin layer of solution came out to the probe surface even after the moisture (u, dry basis) was lower than 0.2. WPI droplets formed thin and smooth skin immediately after coming in contact with hot air. The tensile strength of this skin increased rapidly and peaked (u = 2.14 at 45°C and u = 1. 47 at 65.7°C) fairly early during drying process. WPI droplet surface became completely non-sticky soon after attaining the peak tensile strength (u =1.32 at 53.4 °C and u= 1.05 at 68.8°C), mainly due to transformation of the outer layer of the skin into glassy material. The skin forming and surface active nature of WPI was exploited to minimize the stickiness of honey during spray drying. Replacement of 5% (w/w) maltodextrin with WPI raised the powder recovery of honey solids from 28% to 80%. Stickiness of the WPI on glass, Teflon and polyurethane surfaces was studied by replacing the contact surface of the probe with these materials. It was found that the stickiness of glass surface was the highest at test temperatures. Teflon surface offered the lowest stickiness at the test temperatures making it suitable materials to minimize solution/particle stickiness through coating.
Theoretical study and empirical investigation of sentence analogies
- Authors: Afantenos, Stergos , Lim, Suryani , Prade, Henri , Richard, Gilles
- Date: 2022
- Type: Text , Conference paper
- Relation: 1st Workshop on the Interactions between Analogical Reasoning and Machine Learning at 31st International Joint Conference on Artificial Intelligence - 25th European Conference on Artificial Intelligence, IARML@IJCAI-ECAI 2022, Vienna, Austria, 23 July 2022, CEUR Workshop Proceedings Vol. 3174, p. 15-28
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- Description: Analogies between 4 sentences, “a is to b as c is to d”, are usually defined between two pairs of sentences (a, b) and (c, d) by constraining a relation R holding between the sentences of the first pair, to hold for the second pair. From a theoretical perspective, three postulates define an analogy - one of which is the “central permutation” postulate which allows the permutation of central elements b and c. This postulate is no longer appropriate in sentence analogies since the existence of R offers no guarantee in general for the existence of some relation S such that S also holds for the pairs (a, c) and (b, d). In this paper, the “central permutation” postulate is replaced by a weaker “internal reversal” postulate to provide an appropriate definition of sentence analogies. To empirically validate the aforementioned postulate, we build a LSTM as well as baseline Random Forest models capable of learning analogies based on quadruplets. We use the Penn Discourse Treebank (PDTB), the Stanford Natural Language Inference (SNLI) and the Microsoft Research Paraphrase (MSRP) corpora. Our experiments show that our models trained on samples of analogies between (a, b) and (c, d), recognize analogies between (b, a) and (d, c) when the underlying relation is symmetrical, validating thus the formal model of sentence analogies using “internal reversal” postulate. © 2022 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).
Analogies between sentences : theoretical aspects - preliminary experiments
- Authors: Afantenos, Stergos , Kunze, Tarek , Lim, Suryani , Prade, Henri , Richard, Gilles
- Date: 2021
- Type: Text , Conference paper
- Relation: 16th European Conference on Symbolic and Quantitative Approaches to Reasoning with Uncertainty, ECSQARU 2021 Vol. 12897 LNAI, p. 3-18
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- Description: Analogical proportions hold between 4 items a, b, c, d insofar as we can consider that “a is to b as c is to d”. Such proportions are supposed to obey postulates, from which one can derive Boolean or numerical models that relate vector-based representations of items making a proportion. One basic postulate is the preservation of the proportion by permuting the central elements b and c. However this postulate becomes debatable in many cases when items are words or sentences. This paper proposes a weaker set of postulates based on internal reversal, from which new Boolean and numerical models are derived. The new system of postulates is used to extend a finite set of examples in a machine learning perspective. By embedding a whole sentence into a real-valued vector space, we tested the potential of these weaker postulates for classifying analogical sentences into valid and non-valid proportions. It is advocated that identifying analogical proportions between sentences may be of interest especially for checking discourse coherence, question-answering, argumentation and computational creativity. The proposed theoretical setting backed with promising preliminary experimental results also suggests the possibility of crossing a real-valued embedding with an ontology-based representation of words. This hybrid approach might provide some insights to automatically extract analogical proportions in natural language corpora. © 2021, Springer Nature Switzerland AG.
Improved switching scheme to reduce the junction temperature and power loss of CHB inverters
- Authors: Afrin, Sadia , Biswas, Suvra , Bin Islam, Md Sabbir , Islam, Md Rabiul , Shah, Rakibuzzaman
- Date: 2023
- Type: Text , Conference paper
- Relation: 2023 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices, ASEMD 2023, Tianjin, China, 27-29 October 2023, 2023 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices, ASEMD 2023
- Full Text: false
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- Description: Excessive heating and power loss due to high-frequency switching are always alarming issues in the case of multilevel inverter (MLI) based applications such as solar photovoltaic (PV) systems and industrial drives. Both the heating and power loss of power semiconductor switches significantly rely on the switching pulse width modulation (PWM) scheme employed. This paper proposes an improved switching technique for a solar PV-fed grid-tied 5-level cascaded H-bridge (CHB) inverter, which also reduces the power semiconductor losses of the inverter in relation to several existing switching schemes. The proposed switching scheme employs a modified discontinuous standard mode signal to develop the modulating signal of the proposed method. Level-shifted triangular carrier signals are considered with the proposed switching signal to produce the gate pulses for the 5-level CHB inverter. The performance of the proposed switching scheme is validated through MATLAB/Simulink and PLECS computer simulation environments. © 2023 IEEE.
Efficient low bit-rate intra-frame coding using common information for 360-degree video
- Authors: Afsana, Fariha , Paul, Manoranjan , Murshed, Manzur , Taubman, David
- Date: 2020
- Type: Text , Conference paper
- Relation: 22nd IEEE International Workshop on Multimedia Signal Processing, MMSP 2020
- Full Text: false
- Reviewed:
- Description: With the growth of video technologies, super-resolution videos, including 360-degree immersive video has become a reality due to exciting applications such as augmented/virtual/mixed reality for better interaction and a wide-angle user-view experience of a scene compared to traditional video with narrow-focused viewing angle. The new generation video contents are bandwidth-intensive in nature due to high resolution and demand high bit rate as well as low latency delivery requirements that pose challenges in solving the bottleneck of transmission and storage burdens. There is limited optimisation space in traditional video coding schemes for improving video coding efficiency in intra-frame due to the fixed size of processing block. This paper presents a new approach for improving intra-frame coding especially at low bit rate video transmission for 360-degree video for lossy mode of HEVC. Prior to using traditional HEVC intra-prediction, this approach exploits the global redundancy of entire frame by extracting common important information using multi-level discrete wavelet transformation. This paper demonstrates that the proposed method considering only low frequency information of a frame and encoding this can outperform the HEVC standard at low bit rates. The experimental results indicate that the proposed intra-frame coding strategy achieves an average of 54.07% BD-rate reduction and 2.84 dB BD-PSNR gain for low bit rate scenario compared to the HEVC. It also achieves a significant improvement in encoding time reduction of about 66.84% on an average. Moreover, this finding also demonstrates that the existing HEVC block partitioning can be applied in the transform domain for better exploitation of information concentration as we applied HEVC on wavelet frequency domain. © 2020 IEEE.
Efficient scalable 360-degree video compression scheme using 3d cuboid partitioning
- Authors: Afsana, Fariha , Paul, Manoranjan , Murshed, Manzur , Taubman, David
- Date: 2022
- Type: Text , Conference paper
- Relation: 29th IEEE International Conference on Image Processing, ICIP 2022 p. 996-1000
- Full Text: false
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- Description: Video coding techniques minimize spatial and temporal redundancies inherent in video sequences based on non-overlapping block-based image partitioning. Due to depending on the information from already encoded neighboring blocks, these algorithms lack efficient techniques to exploit the overall global redundancies. Compared to the traditional block-based coding, the cuboid coding (2D) framework has been proven to be a more effective method of image compression that exploits global redundancy by considering homogeneous pixel correlation within a frame. In this paper, we improved the idea of 2D cuboid coding to exploit both local and global redundancy from a video sequence by adopting a three-dimensional (3D) cuboid partitioning scheme for SHVC compression improvement of 360-degree videos. The proposed method considers a group of successive frames as a 3D cuboid and recursively partitions it into sub-3D cuboids where static information over a selected GOP share the same cuboid and moving regions share new cuboids with better-defined objects. All the 3D cuboids are then encoded to create a coarse representation of the video stream. Experiments indicate that the proposed framework significantly outperforms its relevant benchmarks, notably by 17.18% (average) in BD-Rate reduction and 0.82 dB in BD-PSNR gain with respect to the standard SHVC codec. © 2022 IEEE.
Investigation of microgrid instability caused by time delay
- Authors: Aghanoori, Navid , Masoum, Mohammad , Islam, Syed , Nethery, Steven
- Date: 2017
- Type: Text , Conference proceedings , Conference paper
- Relation: 10th International Conference on Electrical and Electronics Engineering, ELECO 2017; Bursa, Turkey; 29th-2nd December 2017 Vol. 2018, p. 105-110
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- Description: This paper investigates the impact of time delay in the control of a grid-connected microgrid with renewable energy resources. The considered microgrid has a critical load that needs to be powered and protected in the event of grid voltage disturbance while the microgrid maintains connection to the grid. Three case studies are performed considering three different time delays to indicate the advantages of fast communication system in the performance of renewable microgrids. Detailed simulation results illustrate that the proposed communication system using IEC 61850 substation automation standard provides better voltage and current quality to the critical local load with larger phase and gain margins while keeping the microgid connected to main grid.
Security issues in statistical databases and implementation of audit expert
- Authors: Ahmad, Abeed , Miller, Mirka
- Date: 2004
- Type: Text , Conference paper
- Relation: Paper presented at ICCC 2004: International Conference on Computers and Communications, Baile Felix Spa-Oradea, Romania : 27th - 29th May, 2004
- Full Text: false
- Reviewed:
- Description: E1
- Description: 2003000899
Constraint-based evolutionary learning approach to the non-normal process performance evaluation
- Authors: Ahmad, S. , Huda, Shamsul , Bakir, S. , Abdollahian, Mali , Zeephongsekul, P.
- Date: 2009
- Type: Text , Conference paper
- Relation: Paper presented at 3rd International Conference on Informatics and Technology 2009: ICT Opportunities in the Current Global Recession, Kuala Lumpur, Malaysia : 27th-28th October 2009 p. 26-33
- Full Text: false
- Description: Performance of industrial products is very important for an industry. Conventional methods for performance analysis consider a normality assumption and limited to low dimensional data. Different manufacturing processes very often have products with quality characteristics that do not follow normal distribution. In such cases fitting a known non-normal distribution to these quality characteristics would lead to erroneous results while assessing the performance of products. In this paper, we propose a novel method for non-normal multivariate process performance analysis. We have proposed a Constraint-based Evolutionary Algorithm (EA) approach for optimal estimation of the parameters of non-normal multivariate process. Furthermore, a geometric distance based method has been employed to reduce higher dimensionality of data to lower dimension. The efficacy of the proposed method is assessed by using the proportion of nonconformance (PNC) criterion to summarize the performance of EA approach. The experimental results from constraint-based EA have been compared to those obtained using steepest descent and simulated annealing (SA) approaches.
- Description: 2003007898
Process performance evaluation using evolutionary algorithm
- Authors: Ahmad, S. , Huda, Shamsul , Bakir, S. , Abdollahian, Mali , Zeephongsekul, P.
- Date: 2009
- Type: Text , Conference paper
- Relation: Paper presented at 2009 International Conference on Information & Knowledge Engineering, IKE 2009, Las Vegas, Nevada, U.S.A. : 13th-16th July 2009 p. 731-737
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- Description: Nowadays every business is using different quantitative measures and techniques to assess performance of their products / services. It is well known that different manufacturing processes very often manufacture products with quality characteristics that do not follow normal distribution. In such cases, fitting a known non-normal distribution to these quality characteristics would lead to erroneous results. Furthermore, there is always more than one characteristic Critical to Quality (CTQ) in the process outcomes and very often these quality characteristics are correlated with each other. In this paper, we assess performance of such a bivariate process data which is non-normal as well as correlated. We will use the geometric distance approach to reduce the dimension of the correlated non-normal bivariate data and then fit Burr distribution to the geometric distance variable. The optimal parameters of the fitted Burr distribution are estimated using Evolutionary Algorithm (EA). The results are compared with those using Simulated Annealing (SA) algorithm. The proportion of nonconformance (PNC) for process measurements is then obtained by using the fitted Burr distributions based on the two methods. The results based on both search algorithms are then compared with the exact proportion of nonconformance of the data. Finally, a case study using real data is presented.
- Description: 2003008140
Geographic constraint mobility model for ad hoc network
- Authors: Ahmed, Sabbir , Karmakar, Gour , Kamruzzaman, Joarder
- Date: 2008
- Type: Text , Conference paper
- Relation: Proceedings of the 2008 IEEE International Symposium on Modeling, Analysis & Simulation of Computer & Telecommunication Systems
- Full Text: false
- Reviewed:
- Description: In this paper, we propose a mobility model and present its simulation tool to generate realistic mobility traces for mobile ad hoc network. The mobility model is capable of creating realistic node movement pattern in the presence of geographic constraints by exploiting the concepts of anchors. The model dynamically places anchors depending upon the context of the environment through which nodes are guided to move towards the destination, and obstacles of arbitrary shapes with or without doorways and any existing pathways, in full or part of the terrain can be incorporated which makes the simulation environment more realistic. The characteristics of the proposed mobility model tested on a real world university campus map at various movement patterns are presented that illustrate the impact of the mobility model on the performance of a routing protocol and usefulness of the proposed scenario generation tool.
Benefit based transmission expansion planning for ASEAN power grid
- Authors: Ahmed, Tofael , Mekhilef, Saad , Shah, Rakibuzzaman
- Date: 2021
- Type: Text , Conference paper
- Relation: 31st Australasian Universities Power Engineering Conference, AUPEC 2021, Virtual, Online 26 to 30 September 2021, Proceedings of 2021 31st Australasian Universities Power Engineering Conference, AUPEC 2021
- Full Text: false
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- Description: This paper presents the cost-benefit assessment related to ASEAN Power Grid (APG) integration. This paper explores the benefit of investment in APG by means of cross-border electricity transmission investment in ASEAN region by 2030. The benefit of investing in the cross-border transmission is analyzed by considering the expected generation portfolio. The net market evaluation framework of APG interconnection is developed, including consumer, producer, and transmission owner benefit for APG interconnection. The impact of cross-border transmission capacity on the net market benefit is analyzed by considering the cross-border transmission capacity limit reported by the ASEAN Centre of Energy (ACE) and optimal transmission limits. The study has been conducted in Matlab/MATPOWER using the simulation model of APG. © 2021 IEEE.
A coarse representation of frames oriented video coding by leveraging cuboidal partitioning of image data
- Authors: Ahmmed, Ashe , Paul, Manoranjan , Murshed, Manzur , Taubman, David
- Date: 2020
- Type: Text , Conference paper
- Relation: 22nd IEEE International Workshop on Multimedia Signal Processing, MMSP 2020, Virtual Tampere, Finland 21-24 September 2020
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- Description: Video coding algorithms attempt to minimize the significant commonality that exists within a video sequence. Each new video coding standard contains tools that can perform this task more efficiently compared to its predecessors. In this work, we form a coarse representation of the current frame by minimizing commonality within that frame while preserving important structural properties of the frame. The building blocks of this coarse representation are rectangular regions called cuboids, which are computationally simple and has a compact description. Then we propose to employ the coarse frame as an additional source for predictive coding of the current frame. Experimental results show an improvement in bit rate savings over a reference codec for HEVC, with minor increase in the codec computational complexity. © 2020 IEEE.