Sharing and Access Right Delegation for Confidential Documents: A Practical Solution

This paper addresses a practical problem in Document Management Systems for which no existing solution is available in the market. To store confidential documents in a Document Management System, a common approach is to keep only the encrypted version of the documents to ensure the confidentiality of the contents. However, how to share these encrypted documents and how to delegate the access rights of these documents are not straightforward while these operations are common in most companies. In this paper, we discuss the issues related to this problem and provide a practical and easy-to-implement solution for solving the problem. Our solution has been shown to be feasible by a prototype implementation. We also show how to extend our solution to take advantage of the hierarchical structure of a company to make it more scalable. As a remark, this problem was initiated by a local company based on its actual needs to fulfil a set of business objectives and requirements

Design, analysis, and testing of high frequency passively damped struts

Objectives of the research are: (1) to develop design requirements for damped struts to stabilize control system in the high frequency cross-over and spill-over range; (2) to design, fabricate and test viscously damped strut and viscoelastically damped strut; (3) to verify accuracy of design and analysis methodology of damped struts; and (4) to design and build test apparatus, and develop data reduction algorithm to measure strut complex stiffness. In order to meet the stringent performance requirements of the SPICE experiment, the active control system is used to suppress the dynamic responses of the low order structural modes. However, the control system also inadvertently drives some of the higher order modes unstable in the cross-over and spill-over frequency range. Passive damping is a reliable and effective way to provide damping to stabilize the control system. It also improves the robustness of the control system. Damping is designed into the SPICE testbed as an integral part of the control-structure technology

The automorphism group of separable states in quantum information theory

We show that the linear group of automorphism of Hermitian matrices which preserves the set of separable states is generated by \emph{natural} automorphisms: change of an orthonormal basis in each tensor factor, partial transpose in each tensor factor, and interchanging two tensor factors of the same dimension. We apply our results to preservers of the product numerical range.Comment: 15 page

A systematic review and meta-analysis of psychosocial interventions aiming to reduce risks of suicide and self-harm in psychiatric inpatients

Psychosocial interventions, such as Cognitive Behavioural Therapy (CBT), are often recommended in UK clinical guidelines to reduce suicidality and self-harm in service users with serious mental health problems, but the effectiveness of these interventions in acute mental health inpatient settings is not established. The aim of this study is to examine the types, and effectiveness of psychosocial interventions in inpatients settings in reducing the risk of self-harm and suicidality. A systematic review and meta-analysis was conducted of randomised controlled trials (RCTs) examining the efficacy of suicide and self-harm focused inpatient psychosocial interventions on suicidality (primary outcome), depression, hopelessness and suicide attempts (secondary outcomes). A total of ten studies met eligibility criteria were included in this review. All had low to moderate risk of bias for majority of the indicators, except for blinding of participants where all studies had high risk of bias. All studies examined psychosocial interventions for suicide reduction and none examined a psychosocial intervention for self-harm. The majority of the psychosocial interventions were CBT and Dialectical Behavioural Therapy (DBT). The interventions were no more effective than control treatments in reducing suicidality, depression, hopelessness or suicide attempts post-therapy and at follow-up. However, the majority were small pilot or feasibility RCTs. In conclusion, the findings from this review suggests that psychosocial interventions are not any more effective in reducing suicidality in acute mental health inpatient settings than control interventions. However, a large-scale RCT examining a psychosocial intervention for suicide is needed to provide conclusive findings. There were also no identified RCTs examining self-harm interventions indicating a need to conduct research in this area

Higher rank numerical ranges of normal matrices

The higher rank numerical range is closely connected to the construction of quantum error correction code for a noisy quantum channel. It is known that if a normal matrix $A \in M_n$ has eigenvalues $a_1, \..., a_n$, then its higher rank numerical range $\Lambda_k(A)$ is the intersection of convex polygons with vertices $a_{j_1}, \..., a_{j_{n-k+1}}$, where $1 \le j_1 < \... < j_{n-k+1} \le n$. In this paper, it is shown that the higher rank numerical range of a normal matrix with $m$ distinct eigenvalues can be written as the intersection of no more than $\max\{m,4\}$ closed half planes. In addition, given a convex polygon ${\mathcal P}$ a construction is given for a normal matrix $A \in M_n$ with minimum $n$ such that $\Lambda_k(A) = {\mathcal P}$. In particular, if ${\mathcal P}$ has $p$ vertices, with $p \ge 3$, there is a normal matrix $A \in M_n$ with $n \le \max\left\{p+k-1, 2k+2 \right\}$ such that $\Lambda_k(A) = {\mathcal P}$.Comment: 12 pages, 9 figures, to appear in SIAM Journal on Matrix Analysis and Application

Improving Query Performance by Clustering XML Documents

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Subinguinal microsurgical varicocelectomy for male factor subfertility: a ten-year experience

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Improving Query Performance by Clustering XML Documents

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Business intelligence systems and operational capability: an empirical analysis of high-tech sectors

202105 bchyAccepted ManuscriptRGC155009/15BPublishe