11,568 research outputs found

    Secure end-to-end browsing system with mobile composition

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    To fix the more and more serious leakage problem in remote access to confidential data, the paper designs and implements a secure end-to-end browsing system with mobile composition. It enables mobile-authenticated users to browse confidential files stored at server side using their personal computers securely. The authentication function is in real-time such that the system can stop the browsing function once it detects that the authenticated mobile is out of the communication range of user's personal computer. © 2011 IEEE.published_or_final_versio

    Assessing photochemical ozone formation in the Pearl River Delta with a photochemical trajectory model

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    A photochemical trajectory model (PTM), coupled with the Master Chemical Mechanism (MCM) describing the degradation of 139 volatile organic compounds (VOCs) in the troposphere, was developed and used for the first time to simulate the formation of photochemical pollutants at Wangqingsha (WQS), Guangzhou during photochemical pollution episodes between 12 and 17 November, 2007. The simulated diurnal variations and mixing ratios of ozone were in good agreement with observed data (R2=0.80, P<0.05), indicating that the photochemical trajectory model - an integration of boundary layer trajectories, precursor emissions and chemical processing - provides a reasonable description of ozone formation in the Pearl River Delta (PRD) region. Calculated photochemical ozone creation potential (POCP) indices for the region indicated that alkanes and oxygenated organic compounds had relatively low reactivity, while alkenes and aromatics presented high reactivity, as seen in other airsheds in Europe. Analysis of the emission inventory found that the sum of 60 of the 139 VOC species accounted for 92% of the total POCP-weighted emission. The 60 VOC species include C2-C6 alkenes, C6-C8 aromatics, biogenic VOCs, and so on. The results indicated that regional scale ozone formation in the PRD region can be mainly attributed to a relatively small number of VOC species, namely isoprene, ethene, m-xylene, and toluene, etc. A further investigation of the relative contribution of the main emission source categories to ozone formation suggested that mobile sources were the largest contributor to regional O3 formation (40%), followed by biogenic sources (29%), VOC product-related sources (23%), industry (6%), biomass burning (1%), and power plants (1%). The findings obtained in this study would advance our knowledge of air quality in the PRD region, and provide useful information to local government on effective control of photochemical smog in the region. © 2010 Elsevier Ltd

    Applying a new interatomic potential for the modelling of hexagonal and orthorhombic YMnO3

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    We develop and apply an interatomic potential for YMnO3, based on the shell model together with the angular overlap model, which can model ligand field effects. The potential parameters accurately reproduce the complex structure of both hexagonal and orthorhombic phases of YMnO3. The rotation of the MnO6 octahedra in o-YMnO3 suggests the E-type AFM order. The potential is further employed to investigate the energies of intrinsic defects in the material. Lower defect energies were found in o-YMnO3. Oxygen Frenkel and Y2O3 partial Schottky are the most favourable defects in h-YMnO3 and o-YMnO3, respectively. The defect models proposed have implications for the properties of the related non-stoichiometric phases

    Efficient key integrity verification for quantum cryptography using combinatorial group testing

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    Quantum Information and Computation VIII 77020F (April 23, 2010)In quantum cryptography, the key can be directly distributed to the communicating parties through the communication channel. The security is guaranteed by the quantum properties of the channel. However, the transmitted key may contain errors due to the noise of the channel. Key integrity verification is an indispensable step in quantum cryptography and becomes an important problem in higher speed systems. Computing only one hash value for the key string does not provide an effective solution as it may lead to dropping all the bits once the hash values on both sides do not agree. In this paper, we introduce a new idea of using the technique of combinatorial group testing, which seems to be an unrelated topic, to design a scheme to identify the error bits to avoid dropping all the bits. Our scheme can precisely locate the error bits if the number of error bits is within the maximum set by the scheme while the overhead is insignificant based on our experiments (additional bits: 0.1% of the key; time for computing the hash values: 16ms; verification time: 22 ms). Also, even if the number of error bits is higher than the maximum set by the scheme, only some correct bits may be misclassified as error bits but not the vice versa. The results show that we can still keep the majority of the correct bits (e.g. the bits discarded due to misclassification is only 5% of the whole string even if the number of error bits is 10 times of the maximum). © 2010 SPIE.published_or_final_versionThe 2010 SPIE Conference on Defense, Security, and Sensing, Orlando, FL., 5 April 2010. In Proceedings of SPIE - The International Society for Optical Engineering, v. 7702, p. 77020F-1 - 77020F-

    Investigating and analyzing the web-based contents on Chinese Shanzhai mobile phones

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    Chinese Shanzhai mobile phone has had a huge commercial market in China and overseas and was found to be involved in criminal cases. In this paper, a MTK-based Shanzhai phone with private web browser was investigated to extract user's web browsing data in the form of sites visited, received emails, attempted Internet searches and etc. Based on the findings, extracting Internet search conducted and web email received from the binary image was demonstrated. Besides, deleted browsing history can be recovered from snapshots in memory help reconstruct user's browsing activity and timeline analysis.postprintThe 7th International Workshop on Systematic Approaches to Digital Forensic Engineering (IEEE/SADFE 2012), Vancouver, BC., 26-28 September 2012, p. 1297-130

    Why and how the work of Motor Neurone Disease Associations matters before and during bereavement: a consumer perspective

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    Background: Studies on the experiences of consumers with Motor Neurone Disease Associations at end of life and bereavement are lacking, and their role and capability within the broader sectors of health and disability are unknown. Objectives: To ascertain the experiences and views of bereaved motor neurone disease caregivers with Motor Neurone Disease Associations about service gaps and needed improvements before and during bereavement and to propose a model of care that fits with consumer preferences and where Motor Neurone Disease Associations are effective enablers of care. Methods: A national bereavement survey was facilitated in 2019 by all Motor Neurone Disease Associations in Australia. A total of 363 respondents completed the section on support provided by Motor Neurone Disease Associations. A mixed-method design was used. Results: Respondents were generally positive about support received before bereavement (73-76%), except for emotional support (55%). Positive experiences related to the following: information, equipment advice/provision, advocacy/linking to services, showing empathy/understanding, personal contact and peer social support. Negative experiences included lack of continuity in case management and contact, perceived lack of competence or training, lack of emotional support and a lack of access to motor neurone disease services in rural areas. Suggested improvements were as follows: more contact and compassion at end of life and postdeath; better preparation for end of life; option of discussing euthanasia; providing referrals and links for counseling; access to caregiver support groups and peer interaction; provision of a genuine continuum of care rather than postdeath abandonment; guidance regarding postdeath practicalities; and more access to bereavement support in rural areas. Conclusion: This study provides consumer perspectives on driving new or improved initiatives by Motor Neurone Disease Associations and the need for a national standardised approach to training and service delivery, based on research evidence. A public health approach to motor neurone disease end-of-life care, of international applicability, is proposed to address the needs and preferences of motor neurone disease consumers, while supporting the capability of Motor Neurone Disease Associations within a multidisciplinary workforce to deliver that care

    A dual cube hashing scheme for solving LPP integrity problem

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    In digital forensics, data stored in a hard disk usually contains valuable evidence. Preserving the integrity of the data in the hard disk is a critical issue. A single hash value for the whole hard disk is not appropriate as the investigation may take a long time and latent sector errors (LSEs) (bad sectors due to media imperfection, for example) which cause a sector suddenly unreadable will make the hash value inconsistent. On the other hand, using a hash per sector may need to store a lot of hash values. Previous research has been conducted to use fewer hash values, but can resist some of LSEs to decrease the number of unverifiable sectors even if there are LSEs. This integrity problem is more complicated in the presence of Legal Professional Privileged (LPP) data inside a seized hard disk in digital forensic as the hard disk has to be cloned once seized and the original hard disk will be sealed after cloning. Hash values need to be computed during this cloning process. However, the cloned copy will be returned to the suspect for the deletion of LPP data before the investigator can work on the sanitized copy. Thus, the integrity of unmodified sectors has to be verified using the hash values computed based on the original hard disk. This paper found that existing schemes are not good enough to solve the integrity problem in the presence of both LSEs and deletion of LPP data. We then propose the idea of a "Dual Cube" hashing scheme to solve the problem. The experiments show the proposed scheme performs better than the previous schemes and fits easily into the digital forensic procedure. © 2011 IEEE.published_or_final_versionThe 6th International Workshop on Systematic Approaches to Digital Forensic Engineering In conjunction with the IEEE Security and Privacy Symposium (IEEE/SADFE 2011), Oakland, CA., 26 May 2011. In IEEE/SADFE Proceedings, 2011, p. 1-

    Emotion-corpus guided lexicons for sentiment analysis on Twitter.

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    Research in Psychology have proposed frameworks that map emotion concepts with sentiment concepts. In this paper we study this mapping from a computational modelling perspective with a view to establish the role of an emotion-rich corpus for lexicon-based sentiment analysis. We propose two different methods which harness an emotion-labelled corpus of tweets to learn world-level numerical quantification of sentiment strengths over a positive to negative spectrum. The proposed methods model the emotion corpus using a generative unigram mixture model (UMM), combined with the emotion-sentiment mapping proposed in Psychology [6] for automated generation of sentiment lexicons. Sentiment analsysis experiments on benchmark Twitter data sets confirm the equality of our proposed lexicons. Further a comparative analysis with standard sentiment lexicons suggest that the proposed lexicons lead to a significantly better performance in both sentimentclassification and sentiment intensity prediction tasks
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