Four dimensional hyperchaotic communication system based on dynamic feedback synchronization technique for image encryption systems

<span>This paper presents the design and simulation of a hyperchaotic communication system based on four dimensions (4D) Lorenz generator. The synchronization technique that used between the master/transmitter and the slave/receiver is based on dynamic feedback modulation technique (DFM). The mismatch error between the master dynamics and slave dynamics are calculated continuously to maintain the sync process. The information signal (binary image) is masked (encrypted) by the hyperchaotic sample x of Lorenz generator. The design and simulation of the overall system are carried out using MATLAB Simulink software. The simulation results prove that the system is suitable for securing the plain-data, in particular the image data with a size of 128×128 pixels within 0.1 second required for encryption, and decryption in the presence of the channel noise. The decryption results for gray and colored images show that the system can accurately decipher the ciphered image, but with low level distortion in the image pixels due to the channel noise. These results make the proposed cryptosystem suitable for real time secure communications.</span>

Hospital management practices in county-level hospitals in rural China and international comparison

Background Although management is important in healthcare, low- and middle-income countries (LMICs) have little experience measuring the competence of hospital management. While improving hospital management is the main focus of hospital reform in China, few studies have empirically documented the baseline situation to inform policy design. Methods We assessed the management practices of county-level hospitals in Guizhou in southwest China during 2015. We used the Development World Management Survey (D-WMS) instrument to interview 273 managers in 139 hospitals. We scored the management practices of the sampled hospitals, overall and in four dimensions (operations, monitoring, targets, personnel management) and three processes (implementation, usage, monitoring). We then converted the scores to the WMS scale and compared these with data from two other LMICs and seven high-income countries (HICs). Results On a scale of 1 (‘worst practice’) to 5 (‘best practice’), the mean (SD) hospital D-WMS scores were 2.57 (0.46) overall; 2.71 (0.48), 2.64 (0.58), 2.40 (0.64), and 2.56 (0.40) for operation, monitoring, target, and personnel, respectively; and 2.43 (0.48), 2.62 (0.48), and 2.66 (0.47) for implementation, usage, and monitoring, respectively. After conversion to WMS scores, China ranked seventh of 10 countries, after six HICs and higher than one HIC and two other LMICs (Brazil and India). China ranked higher than the two LMICs in each of the four dimensional scores. Conclusions Chinese county-level hospitals should improve their low quality of management by prioritizing target-setting and process implementation, particularly in personnel management. Meanwhile, modern management training should be given to most clinical managers.

Validation of the Orgasm Rating Scale in Context of Sexual Relationships of Gay and Lesbian Adults

Currently, no validated instrument exists for assessing the subjective experience of orgasm in the gay population. The Orgasm Rating Scale (ORS), previously validated in the heterosexual population, comprises four dimensions: Affective, Sensory, Intimacy, and Rewards. This study validated it for sexual relationships in the gay population by obtaining its factorial invariance by sexual orientation and sex, its internal consistency reliability, and evidence of validity in its relationship with other variables. We assessed 1600 cisgender Spanish adults–heterosexuals, gays, and lesbians–divided into 4, sex-based groups of 400 each, according to the Kinsey scale scores. Participants reported recent experiences of orgasm in the context of sexual relationships and responded to the ORS and other scales assessing attitude toward sexual fantasies and sexual functioning. The ORS structure showed a strict multigroup-level invariance by sexual orientation and sex, confirming its four-dimensional structure. The subjective orgasm intensity was associated with a positive attitude toward sexual fantasies and sexual functioning. Scores obtained on the Affective, Intimacy, and Rewards dimensions confirmed the ability to discriminate between gay people with and without orgasmic difficulties. The ORS’s Spanish version presents good psychometric properties as a validated scale to evaluate the subjective experience of orgasm in the gay population.

Research on the Matching Relationship between the Supply of Urban Ecological Recreational Space and the Demand of Residents—A Case Study of an Urban Development Area in Wuhan

An urban ecological recreational space (UERS), which connects the natural environment with urban residents, is an important guarantee for developing a livable city and improving the well-being of residents. However, there is a serious imbalance between the supply of UERSs and the demand of residents in many big, rapidly developing cities. Previous studies usually used indicators such as scale or quantity to measure the supply level of UERS enjoyed by residents, ignoring its own quality differences. Therefore, taking the urban development area of Wuhan as the research object, we measured the quality of UERS from four dimensions using the entropy method and designed a method to measure the supply service level under the hierarchical travel threshold to analyze the supply level of UERSs based on a community unit. Finally, combined with the demand characteristics of different groups, the matching relationship between supply and demand of UERSs in each community is quantitatively analyzed. The results show the following: (1) The quality of UERS in urban development area of Wuhan varies greatly and its distribution is extremely uneven. (2) The level of supply services and the demand level vary greatly, and the overall performance has a trend of decreasing from the city center to the periphery. (3) The overall matching relationship between supply and demand of UERS is not ideal, and more than half of the communities are in supply deficit or without services. Our study provides a novel perspective on quantifying the supply–demand relationship of UERS. It can more accurately guide decision-makers and planners in determining areas with mismatches between the supply and demand of UERSs and in making targeted layouts of UERSs and relevant policies.

Unleading during a pandemic: Scrutinising leadership and its impact in a state of exception

Characterising COVID-19 pandemic as a ‘state of exception’, we might expect great hero models of leadership to come to the fore. Instead, drawing on a thematic analysis of 246 news articles, this paper illustrates something different: communities, companies, individuals picked-up the leadership mantle but were reluctant to frame their practices under a leadership rhetoric. The paper explores spontaneous initiatives and leaderly actions that were made visible during the pandemic and proposes practice-based implications for redrawing leadership conceptualisations. These practices, coined as unleading, are characterised under four dimensions: unconditionality and social intention; purposeful action in the absence of an achievement motivation; sensing and attending to local conditions; and confident connecting and collaborating. The analysis and discussion of the four dimensions affirm that while leading and unleading are always present when organising, they are more or less visible and practiced depending on organisational, social and individual circumstances. The paper concludes by surfacing questions and reflections for the future of unleading and implications for leadership theorising and practice.

The perception of success in the halal market: developing a halal entrepreneurship success scale

Purpose The purpose of this paper is to examine how Halal entrepreneurs perceive success and accordingly develop a novel scale to measure Halal entrepreneurship success. Design/methodology/approach A sequential mixed methodology was used to develop the Halal entrepreneurship success scale (HESS). The qualitative phase began with a literature review to gain insights into (Halal) entrepreneurship success and identify gaps. Ten respondents were then interviewed to understand how they perceive success. The scale items were then generated based on insights from the literature and the interview findings. The quantitative phase was carried out in two cycles. In the first cycle, a questionnaire was developed and pilot data were collected from a representative sample of 100 respondents. In the second cycle, the revised scale was tested on 300 respondents to confirm its final items and dimensions. Exploratory factor analysis and confirmatory factor analysis were used in the quantitative phase. Findings The final HESS scale contains 24 items divided into four dimensions: Islamic success (seven items), economic success (six items), social success (five items) and environmental success (six items). Originality/value This scale is perhaps the first to measure entrepreneurial success in its association with religion. It is expected to be a useful contribution to entrepreneurship theory and the Halal industry. The paper presents a foundation for future works on how to define the measures of success of Halal entrepreneurs.

Developing a pedagogical instrument for MIS fundamental course – embracing self-regulated learning strategies

Purpose Teaching management information systems (MIS) fundamental course remains a challenging task to date, encountering several continuing complaints from students as well as instructors, as per several studies. Several reasons are reported, some of which are related to little embrace of more innovative non-traditional techniques, and limited literature guidance on selection and effective use of appropriate strategies to various settings. Toward instructional innovation, this paper proposes and tests a pedagogical instrument. By introducing this tool, the ultimate objective is to minimize the confusion that students usually encounter during this course and to empower the instructors in the delivery of its interdisciplinary knowledge. Design/methodology/approach A triangulation of four methods is being employed: conceptual development, experimentation for 12 years, assessment in light of the self-regulated learning theory, and empirical analysis. For the latter method, an open-ended questionnaire as well as group interviewing were carried out. Findings The proposed instrument (need-function instrument [NFI]) was found to be in support of self-regulated learning to a promising extent in terms of its four core aspects. The participants were more inclined to accept as well as appreciate the instrument than report drawbacks. Yet, there are few complaints for the inability to distinguish between two introduced terms, ‘Information Problem’ and ‘Operations Problem’. Therefore, a future effort is deemed necessary to explore this aspect. Research limitations/implications The results are based on a single case of educational institution which is not enough to generalize for other educational environments. Future research is necessary for testing in a variety of settings in terms of type of classroom, number of students enrolled, type of institution (public or private), etc. Practical implications Whereas the instrument is anticipated to render improvements in the students’ understanding of MIS content and to alleviate the task of the course leader in delivering the course, there are possible practical implications that should be paid careful attention to. They were analyzed in terms of four dimensions: the Instructor, the Student, the Classroom and Time. Originality/value The paper introduces a new pedagogical instrument/tool for teaching the MIS fundamental course.

Literatura policial y policía: reflexiones a partir de dos intervenciones críticas (José Pablo Feinmann y Carlos Gamerro)

I propose a close reading on two critical interventions about crime fiction in Argentina: “Estado policial y novela negra argentina” (1991) by José Pablo Feinmann and “Para una reformulación del género policial argentino” (2006) by Carlos Gamerro. Beyond the time difference between the two, I observe aspects in common. Both texts elaborate a corpus of writers and fictions; propose an interpretative guide between the literary and the political-social series; maintain a specific interest in the relationship between crime fiction and police; and elaborate figures of enunciators who serve both as theorists of the genre and as writers of fiction. Among these four dimensions, the one that particularly interests me here is the third, since it allows me to investigate the link that is assumed between “detective fiction” and “police institution”. My conclusion is twofold: on the one hand, in both essays predominates a reductionist vision of the genre, since a kind of necessity is emphasized in the representation of the social order; on the other, its main objective seems to lie in intervening directly on the definitions of the detective fiction in Argentina (and, on this point, both texts acquire an undoubtedly prescriptive nuance).

Completing bases in four dimensions

Criteria for the completion of an incomplete basis of, or context in, a four-dimensional Hilbert space by (in)decomposable vectors are given. This, in particular, has consequences for the task of ``completing'' one or more bases or contexts of a (hyper)graph: find a complete faithful orthogonal representation (aka coordinatization) of a hypergraph when only a coordinatization of the intertwining observables is known. In general indecomposability and thus physical entanglement and the encoding of relational properties by quantum states ``prevails'' and occurs more often than separability associated with well defined individual, separable states.