Despite the availability of advanced security software and hardware mechanisms available, still, there has been a breach in the defence system of an organization or individual. Social engineering mostly targets the weakest link in the security system <\/span>i.e.<\/span><\/i> “Humans” for gaining access to sensitive information by manipulating human psychology. Social engineering attacks are arduous to defend as such attacks are not easily detected by available security software or hardware. This article surveys recent studies on social engineering attacks with discussion on the social engineering phases and categorizing the various attacks into two groups. The main aim of this survey is to examine the various social engineering attacks on individuals and countermeasures against social engineering attacks are also discussed.
Highlights • The objective of this paper is to help designers review the causal relationships between software design elements. • In Design Association Theory, causal relationship is the basis of associating architectural design concerns, design problems and design solutions. • We propose an association-based five-step review procedure to systematically identify design reasoning issues. • We studied three industrial software architecture design cases, and found design reasoning issues in all three cases. • We generalize reasoning failures into eight different design reasoning failure scenarios. Abstract During the process of software design, software architects have their reasons to choose certain software components to address particular software requirements and constraints. However, existing software architecture review techniques often rely on the design reviewers’ knowledge and experience, and perhaps using some checklists, to identify design gaps and issues, without questioning the reasoning behind the decisions made by the architects. In this paper, we approach design reviews from a design reasoning perspective. We propose to use an association-based review procedure to identify design issues by first associating all the relevant design concerns, problems and solutions systematically; and then verifying if the causal relationships between these design elements are valid. Using this procedure, we discovered new design issues in all three industrial cases, despite their internal architecture reviews and one of the three systems being operational. With the newly found design issues, we derive eight general design reasoning failure scenarios.
Selective electron beam melting (SEBM) is a typical powder bed fusion based additive manufacturing (AM) technology. Compared with other AM technologies for metals, SEBM offers two distinct advantages: high vacuum environment and low residual stresses. Since the appearance of the technique in 1992, a number of strong improvements have been made to SEBM, and a wide variety of metallic materials have been processed and evaluated. To date, SEBM has proved to be competent in the manufacturing of complex metallic parts with excellent mechanical properties. As a result, it is being increasingly adopted by industry. However, from the point of research and industrial applications, the fundamental research of the technique is not enough and theoretical study of the metallurgical process is of particular importance. Meanwhile, developing advanced systems, new structures and alloys special for SEBM should be important for the future development.
Dong YE
Xiao-xiang WANG
Run-xian WANG
Xin LIU
Hui LIU
Hai-ning WANG
Mercury emission has become a great environmental concern because of its high toxicity, bioaccumulation, and persistence. Adsorption is an effective method to remove Hg0 from coal-fired flue gas, with adsorbents playing a dominant role. Extensive investigations have been conducted on the use of CuO-based materials for Hg0 removal, and some fruitful results have been obtained. In this review, we summarize advances in the application of CuO-based materials for Hg0 capture. Firstly, the fundamentals of CuO, including its crystal information and synthesis methods, are introduced. Then, the Hg0 removal capability of some typical CuO-based adsorbents is discussed. Considering that coal-fired flue gas also contains a certain amount of NO, SO2, H2O, NH3, and HCl, the impacts of these species on adsorbent Hg0 removal efficiency are summarized next. By generalizing the mechanisms dominating the Hg0 removal process, the rate-determining step and the key intermediates can be discovered. Apart from Hg0, some other air pollutants, such as CO, NOx, and volatile organic compounds (VOCs), account for a certain portion of flue gas. In view of their similar abatement mechanisms, simultaneous removal of Hg0 and other air pollutants has become a hot topic in the environmental field. Considering the Hg0 re-emission phenomena in wet flue gas desulfurization (WFGD), mercury capture performance under different conditions in this device is discussed. Finally, we conclude that new adsorbents suitable for long-term operation in coal-fired flue gas should be developed to realize the effective reduction of mercury emissions.
Additive manufacturing (AM),which is also known as three-dimensional (3D) printing,uses computer-aided design to build objects layer by layer.Here,we focus on the recent progress in the development of techniques for 3D printing of glass,an important optoelectronic material,including fused deposition modeling,selective laser sintering/melting,stereolithography (SLA) and direct ink writing.We compare these 3D printing methods and analyze their benefits and problems for the manufacturing of functional glass objects.In addition,we discuss the technological principles of 3D glass printing and applica-tions of 3D printed glass objects.This review is finalized by a summary of the current achievements and perspec-tives for the future development of the 3D glass printing technique.