Secure image encryption scheme using 4D-Hyperchaotic systems based reconfigurable pseudo-random number generator and S-Box

This paper introduces the design of a hardware efficient reconfigurable pseudorandom number generator (PRNG) using two different feedback controllers based four-dimensional (4D) hyperchaotic systems i.e. Hyperchaotic-1 and -2 to provide confidentiality for digital images. The parameter's value of these two hyperchaotic systems is set to be a specific value to get the benefits i.e. all the multiplications (except a few multiplications) are performed using hardwired shifting operations rather than the binary multiplications, which doesn't utilize any hardware resource. The ordinary differential equations (ODEs) of these two systems have been exploited to build a generic architecture that fits in a single architecture. The proposed architecture provides an opportunity to switch between two different 4D hyperchaotic systems depending on the required behavior. To ensure the security strength, that can be also used in the encryption process in which encrypt the input data up to two times successively, each time using a different PRNG configuration. The proposed reconfigurable PRNG has been designed using Verilog HDL, synthesized on the Xilinx tool using the Virtex-5 (XC5VLX50T) and Zynq (XC7Z045) FPGA, its analysis has been done using Matlab tool. It has been found that the proposed architecture of PRNG has the best hardware performance and good statistical properties as it passes all fifteen NIST statistical benchmark tests while it can operate at 79.101-MHz or 1898.424-Mbps and utilize only 0.036 %, 0.23 %, and 1.77 % from the Zynq (XC7Z045) FPGA's slice registers, slice LUTs, and DSP blocks respectively. Utilizing these PRNGs, we design two 16 × 16 substitution boxes (S-boxes). The proposed S-boxes fulfill the following criteria: Bijective, Balanced, Non-linearity, Dynamic Distance, Strict Avalanche Criterion (SAC) and BIC non-linearity criterion. To demonstrate these PRNGs and S-boxes, a new three different scheme of image encryption algorithms have been developed: a) Encryption using S-box-1, b) Encryption using S-box-2 and, c) Two times encryption using S-box-1 and S-box-2. To demonstrate that the proposed cryptosystem is highly secure, we perform the security analysis (in terms of the correlation coefficient, key space, NPCR, UACI, information entropy and image encryption quantitatively in terms of (MSE, PSNR and SSIM)).     

The influence of textese on adolescents’ perceptions of text message writers

Text messages are characterised by a casual language style, ‘textese’ (e.g., c u on thurs). This study investigated adolescents’ perceptions of the use of different levels of textese in digital messages which varied in their intended recipient (friend, teacher). Grade 8 students in Australia (N = 90, aged 13–14 years) each read six text messages purportedly written by a fellow student, and rated the extent to which they agreed (on a 7-point Likert scale) that the message writer was intelligent, paid attention to detail, used an appropriate writing style, and was friendly. Overall, participants rated message senders most favourably on all measures when they used no textese, and least favourably when they used high levels of textese. This pattern was even stronger when messages were addressed to teachers rather than same-aged friends. The findings suggest that adolescents are sensitive to both writing style and recipient when considering digital messages.     

Determinants of the intention to use non-medical insertable digital devices: The case of Chile and Colombia

In the past, thinking of carrying electronic devices inside our bodies was only posed by non-real scenarios. The emergence of insertable devices has changed this. Since this technology is still in its initial development stages, few studies have investigated factors that influence its acceptance. This paper analyzes the predictors of the intention to use non-medical insertable devices in two Latin American contexts. We used partial least squares structural equation modeling to examine whether six constructs predicted intention to use insertable devices. A questionnaire was administered to undergraduate students located in Colombia and Chile (n = 672). We also examined whether these predictors influenced intention differently for both of them. Four common constructs significantly and positively influenced both Chilean and Colombian respondents to use insertable devices (hedonic motivation, habit, performance expectancy, and social influence). Also, the habit has a complementary mediating effect on the relationship between social influence and behavioral intention. By contrast, effort expectations were a positive and significant predictor, but only among Chilean respondents. Findings suggest that when technologies are emerging, well-known predictors of intention (e.g., performance and effort expectations) are less influential than predictors related to self-efficacy (e.g., habit and hedonic motivation). The use of insertable devices has a significant impact on society. Thus, a better understanding of what motivates their use has implications for both academia and industry.     

Digital twin-based analysis of volumetric error mapping procedures

The evaluation of the volumetric accuracy of a machine tool is an open challenge in the industry, and a wide variety of technical solutions are available in the market and at research level. All solutions have advantages and disadvantages concerning which errors can be measured, the achievable uncertainty, the ease of implementation, possibility of machine integration and automation, the equipment cost and the machine occupation time, and it is not always straightforward which option to choose for each application. The need to ensure accuracy during the whole lifetime of the machine and the availability of monitoring systems developed following the Industry 4.0 trend are pushing the development of measurement systems that can be integrated in the machine to perform semi-automatic verification procedures that can be performed frequently by the machine user to monitor the condition of the machine. Calibrated artefact based calibration and verification solutions have an advantage in this field over laser based solutions in terms of cost and feasibility of machine integration, but they need to be optimized for each machine and customer requirements to achieve the required calibration uncertainty and minimize machine occupation time.This paper introduces a digital twin-based methodology to simulate all relevant effects in an artefact-based machine tool calibration procedure, from the machine itself with its expected error ranges, to the artefact geometry and uncertainty, artefact positions in the workspace, probe uncertainty, compensation model, etc. By parameterizing all relevant variables in the design of the calibration procedure, this simulation methodology can be used to analyse the effect of each design variable on the error mapping uncertainty, which is of great help in adapting the procedure to each specific machine and user requirements. The simulation methodology and the analysis possibilities are illustrated by applying it on a 3-axis milling machine tool.     

The emancipatory potential of digital entrepreneurship: A study of financial technology-driven inclusive growth

Digital entrepreneurship possesses immense societal implications beyond its commercial significance. Yet our knowledge of the emancipatory potential of digital entrepreneurship remains limited because few studies have gone beyond the conventional emphasis on profits and wealth creation. Drawing on the emancipatory perspective that views entrepreneurship as change creation through the removal of constraints, this article examines how emancipation can occur through the actions of digital entrepreneurs. Using an empirical investigation of entrepreneurial endeavours set against disadvantaged communities in Indonesia, we uncover constraints facing a developing economy and the role of digital technologies in ameliorating them. Through extensive fieldwork and in-depth case study analyses, we identify constraining societal norms and restrictive practices, as well as the three forms of digital enablement - to emulate services, aggregate capital and equalise opportunities – necessary for the enactment of digitally enabled emancipation. We present a framework to illustrate the enactment of emancipatory digital entrepreneurship for the inclusive development of businesses and communities.     

基于数值微分核脉冲信号数字处理方法

核反应堆核测量系统测量探测器输出的核脉冲信号，该信号后沿拖尾很长，在计数率较高时容易产生信号堆积和基线漂移等问题，导致源区计数率测量上限仅能达到105 Hz左右。文中基于数值微分方法，采用数字处理技术，在时域上分析了核脉冲信号经过前置放大、信号成形、低通滤波和脉冲甄别后的输出，并利用探测器实测信号进行了仿真。仿真结果表明，基于数值微分的数字处理方法可以实现相邻0.4 μs脉冲信号的识别和测量，将源区测量计数率上限提升到2×106 Hz以上。      

Changes in accommodative micro-fluctuations after wearing contact lenses of different optical designs

PurposeAccommodative micro-fluctuations (AMF) are small dioptric changes during accommodation. The aim of this study was to evaluate and compare changes in AMF when wearing silicone hydrogel contact lenses of two different optical designs.MethodsA multi-centre, randomised, cross-over, non-dispensing study was conducted on 68 adapted contact lens wearers aged 25–35 years to compare AMF responses to a spherical and aspheric silicone hydrogel (comfilcon A) lens designs. A Righton Speedy “i” series Auto Refractometer in accommodation analyser mode was utilized before and after reading a standard text in font size 8 on an iPhone 5 for 20 min at a 25 cm viewing distance. Phone screen brightness was set by automatic adjustment mode and ambient illumination was controlled at all sites.ResultsMean ± SD AMF change from before to after the reading task was 2.25 ± 5.6 and 0.13 ± 5.7 (relative values) for the spherical and aspheric lens designs, respectively. The difference was statistically significant (P = 0.017, Paired t-test).ConclusionsThe smaller change in AMF when using an aspheric lens design suggests reduced ciliary muscle stress when reading print on a smart phone at a close distance for short periods (20 min). Contact lens wearers who frequently use digital devices and are experiencing eye strain may benefit from switching from a spherical design to one that incorporates aspheric optics.     

Rainbow over the Internet: How Internet use curtails homophobia in China

China, despite its rapid economic modernization and the lack of powerful conservative institutions, is not known for embracing diverse sexual orientation. The present study investigates whether and how Internet use, a increasingly important part of contemporary people's daily life, leads to changes in people's attitudes toward homosexuality in China, and relevant policy implications. Analyzing the Chinese General Social Survey data from 2010 to 2015, this paper develops an ordered probit model to quantify the influence of Internet use on homosexuality tolerance, adopts a substitution variable method to conduct the robustness check, and utilizes instrument variables to address the potential endogeneity in the regressions. The results show that Internet use has a significant positive impact on Chinese people's homosexuality tolerance. Further studies have found that the influence of Internet use on homosexuality tolerance is also heterogeneous to different populations. Besides, compared with traditional media, the Internet has a more significant impact on homosexuality tolerance. This paper provides some explanations for the rise in China's homosexuality tolerance from 2010 to 2015, and additional impetus for the international community to push for a liberal Internet policy in China.     

Crowdwork platform governance toward organizational value creation

Crowdwork, a new form of digitally mediated employment and part of the so-called gig economy, has the capacity to change the nature of work organization and to provide strategic value to workers, job providers, and intermediary platform owners. However, because crowdwork is temporary, large-scale, distributed, and mediated, its governance remains a challenge that often casts a shadow over its strategic value. The objective of this paper is to shed light on the making of value-adding crowdwork arrangements. Specifically, the paper explores crowdwork platform governance mechanisms and the relationships between these mechanisms and organizational value creation. Building on a comprehensive review of the extant literature on governance and crowdwork, we construct an overarching conceptual model that integrates control system and coordination system as two complementary mechanisms that drive crowdwork platform governance effectiveness and the consequent job provider benefits. Furthermore, the model accentuates the role of the degree of centralization and the degree of routinization as critical moderators in crowdwork platform governance. Overall, the paper highlights the potential of crowdwork to contribute not only to inclusion, fair wages and flexible work arrangements for workers but also to organizations’ value and competitive edge.