Symbolic and Structural Model-Checking

Brute-force model-checking consists in exhaustive exploration of the state-space of a Petri net, and meets the dreaded state-space explosion problem. In contrast, this paper shows how to solve model-checking problems using a combination of techniques that stay in complexity proportional to the size of the net structure rather than to the state-space size. We combine an SMT based over-approximation to prove that some behaviors are unfeasible, an under-approximation using memory-less sampling of runs to find witness traces or counter-examples, and a set of structural reduction rules that can simplify both the system and the property. This approach was able to win by a clear margin the model-checking contest 2020 for reachability queries as well as deadlock detection, thus demonstrating the practical effectiveness and general applicability of the system of rules presented in this paper.

Closest Pair Algorithms in 2D space,a commentary on complexity and reductions

One of the most challenging problems in computational geometry is closest pair of points given n points. Brute force algorithms[1] and Divide and conquer[1] have been verified and the lowest complexity of attributed to latter class of algorithms, with worst case being for the former being . We propose a method of partitioning the set of n-points based on the least area rectangle that can circumscribe these points

Counting Non-Convex 5-Holes in a Planar Point Set

Let S be a set of n points in the general position, that is, no three points in S are collinear. A simple k-gon with all corners in S such that its interior avoids any point of S is called a k-hole. In this paper, we present the first algorithm that counts the number of non-convex 5-holes in S. To our best knowledge, prior to this work there was no known algorithm in the literature except a trivial brute force algorithm. Our algorithm runs in time O(T+Q), where T denotes the number of 3-holes, or empty triangles, in S and Q that denotes the number of non-convex 4-holes in S. Note that T+Q ranges from Ω(n2) to O(n3), while its expected number is Θ(n2logn) when the points in S are chosen uniformly and independently at random from a convex and bounded body in the plane.

nature family

Man is a subject with liberty, truth; An individual is a creative person. The existence of individuals is not separate from the means of living. The means of subsistence is the end, the person is the means, so helplessness, unhappiness, and falsehood appear. Removing falsehoods makes standards defining functions and duties of grandparents, parents, spouses, brothers, and children appear. Standards appear to be meaningful in the ownership, binding, and mutual use of individuals. The existence of standards makes the family the living organization of individuals. Patriarchal habits, brute force, violence, taking advantage of families to hurt each other. Parents defending and protecting their children is an animal instinct, and compliance with standards is irresponsible. The norm that binds individuals to only use each other in the family is not to have universal humanity. Money appears to abolish the false norm becomes to abolish the family. Abolish family norms expressed in separation, divorce, eliminate violence, sexual weakness, respect men, and despise women so that people can relate to each other with common humanity, that is, bring individuals back to life return to a life of freedom, truth, and creativity.

The Foundational Lawlessness of the Law Itself: Racial Criminalization & the Punitive Roots of Punishment in America

Empirical researchers and criminal justice practitioners have generally set aside history in exchange for behavioral models and methodologies that focus primarily on crime itself as the most measurable and verifiable driver of American punitiveness. There are innumerable legal and political questions that have arisen out of these approaches. Everything from the social construction of illegality to the politicization of punishment to the stigmatization of physical identities and social statuses have long called into question the legal structures that underpin what counts as crime and how punishment is distributed. And yet, until quite recently, the question of what history has to offer has mostly been left to historians, historically minded social scientists, critical race and ethnic studies scholars, community and prison-based activists, investigative journalists, and rights advocates. What is at stake is precisely the foundational lawlessness of the law itself. At all times, a White outlaw culture that rewarded brute force and strength of arms against racialized others unsettles basic assumptions about how we are to understand criminalization and punitiveness over time: that is, who has counted as a criminal and to what end has the state used violence or punishment?

Toward Responsible AI: An Overview of Federated Learning for User-centered Privacy-preserving Computing

With the rapid advances of Artificial Intelligence (AI) technologies and applications, an increasing concern is on the development and application of responsible AI technologies. Building AI technologies or machine-learning models often requires massive amounts of data, which may include sensitive, user private information to be collected from different sites or countries. Privacy, security, and data governance constraints rule out a brute force process in the acquisition and integration of these data. It is thus a serious challenge to protect user privacy while achieving high-performance models. This article reviews recent progress of federated learning in addressing this challenge in the context of privacy-preserving computing. Federated learning allows global AI models to be trained and used among multiple decentralized data sources with high security and privacy guarantees, as well as sound incentive mechanisms. This article presents the background, motivations, definitions, architectures, and applications of federated learning as a new paradigm for building privacy-preserving, responsible AI ecosystems.

Two Factor Authentication Berbasis SMS pada Layanan Single Sign-On Universitas Mataram

Keamanan merupakan bagian yang penting dalam hal transaksi elektronik. Sistem informasi di Universitas Mataram secara umum menggunakan metode username dan password untuk melakukan autentikasi (Single Factor Authentication - SFA). Metode SFA rentan dengan serangan brute force terhadap layanan Single Sign On (SSO). Untuk menangkal serangan brute force, penelitian ini mengusulkan implementasi Two Factor Authentication (TFA) berbasis SMS pada SSO. Penelitian ini menemukan pengujian yang dilakukan dengan melakukan analisa pada simulasi serangan brute force tidak dapat menembus akses dari akun pengguna. Pengujian lainnya dengan menggunakan metode User Experience Questionnaire (UEQ) menemukan skor pada aspek Pragmatis adalah 1,927 (Excellent), pada aspek Hedonis adalah 1,667 (Excellent), dan secara keseluruhan adalah 1,797 (Excellent).

Attacks on Graphical Password: A Study on Defense Mechanisms and Limitations

User authentication is mostly reliant on password-based based verification. Users generally used text-based passwords, which are user-friendly but often predictable and vulnerable to some common attacks. To overcome these shortcomings, graphical authentication methods have emerged. Here, users choose a sequence of images as passwords. Though such methods help users to better remember their passwords, they too suffer from attacks seen in the case of textual passwords. This paper presents a comprehensive summary of the vulnerabilities state of the art graphical password schemes against the following well-known attacks - Dictionary, Guessing, Brute force, Shoulder surfing, Spyware, and Social engineering. We believe the findings of this study can help researchers design more secure graphical password schemes making them more usable and a realistic replacement for text-based passwords.

Analisis Keamanan Sistem Informasi Akademik (SIAKAD) Universitas XYZ Menggunakan Metode Vulnerability Assessment

The use of academic information systems (siakad) has become mandatory for universities in providing user convenience in online academic administrative activities. However, sometimes college siakad has security holes that irresponsible people can take advantage of by hacking. This study aims to identify security vulnerabilities at XYZ Siakad University. The method used in this study is a vulnerability assessment method. A university syakad will conduct an initial vulnerability assessment by doing footprinting to get information related to XYZ syakad after that a vulnerability scan is carried out using vulnerability assessment tools to identify vulnerabilities and the level of risk found. Based on the vulnerability of the XYZ university's vulnerabilities, it is quite good, with a high risk level of 1, a medium risk level of 6 and a low risk level of 14. Researchers provide recommendations for improvements related to the findings of security holes in XYZ university Siakad from XSS (Cross Site Scripting) attacks, Clickjacking, Brute Force, Cross-site Request Forgery (CSRF) and Sniffing.

Energy cascades in rapidly rotating and stratified turbulence within elongated domains

We study forced, rapidly rotating and stably stratified turbulence in an elongated domain using an asymptotic expansion at simultaneously low Rossby number $\mathit {Ro}\ll 1$ and large domain height compared with the energy injection scale, $h=H/\ell _{in}\gg 1$ . The resulting equations depend on the parameter $\lambda =(h \mathit {Ro} )^{-1}$ and the Froude number $\mathit {Fr}$ . An extensive set of direct numerical simulations (DNS) is performed to explore the parameter space $(\lambda,\mathit {Fr})$ . We show that a forward energy cascade occurs in one region of this space, and a split energy cascade outside it. At weak stratification (large $\mathit {Fr}$ ), an inverse cascade is observed for sufficiently large $\lambda$ . At strong stratification (small $\mathit {Fr}$ ) the flow becomes approximately hydrostatic and an inverse cascade is always observed. For both weak and strong stratification, we present theoretical arguments supporting the observed energy cascade phenomenology. Our results shed light on an asymptotic region in the phase diagram of rotating and stratified turbulence, which is difficult to attain by brute-force DNS.