Texture transitions in binary mixtures of 6OBAC with compounds of its homologous series

Recently we have observed in compounds of the 4,n-alkyloxybenzoic acid series, with the homologous index n ranging from 6 to 9, a texture transition in the nematic range which subdivides the nematic phase in two sub-phases displaying different textures in polarised light analysis. To investigate a persistence of texture transitions in nematic phases, we prepared binary mixtures of 4,6-alkyloxybenzoic acid (6OBAC) with other members (7-,8-,9-,12-, 16OBAC) of its homologous series. Binary mixtures exhibit a broadening in the temperature ranges of both smectic and nematic phases. A nematic temperature range of 75 C is observed. In the nematic phase, in spite of the microscopic disorder introduced by mixing two components, the polarised light optics analysis of the liquid crystal cells reveals a texture transition. In the case of the binary mixture of 6OBAC with 12OBAC and with 16OBAC, that is of compounds with monomers of rather different lengths, the texture transition temperature is not homogeneous in the cell, probably due to a local variation in the relative concentrations of compounds.Comment: 13 pages, 9 figure

Introducing probability in Colorwave

Technical Repor

Evaluation Criteria for Reader-to-Reader Anti-collision Protocols

Technical Repor

On Improving Automation by Integrating RFID in the Traceability Management of the Agri-Food Sector

Traceability is a key factor for the agri-food sector. RFID technology, widely adopted for supply chain management, can be used effectively for the traceability management. In this paper, a framework for the evaluation of a traceability system for the agri-food industry is presented and the automation level in an RFID-based traceability system is analyzed and compared with respect to traditional ones. Internal and external traceability are both considered and formalized, in order to classify different environments, according to their automation level. Traceability systems used in a sample sector are experimentally analyzed, showing that by using RFID technology, agri-food enterprises increase their automation level and also their efficiency, in a sustainable wa

Probabilistic DCS: An RFID reader-to-reader anti-collision protocol

The wide adoption of radio frequency identification (RFID) for applications requiring a large number of tags and readers makes critical the reader-to-reader collision problem. Various anti-collision protocols have been proposed, but the majority require considerable additional resources and costs. Distributed color system (DCS) is a state-of-the-art protocol based on time division, without noteworthy additional requirements. This paper presents the probabilistic DCS (PDCS) reader-to-reader anti-collision protocol which employs probabilistic collision resolution. Differently from previous time division protocols, PDCS allows multichannel transmissions, according to international RFID regulations. A theoretical analysis is provided in order to clearly identify the behavior of the additional parameter representing the probability. The proposed protocol maintains the features of DCS, achieving more efficiency. Theoretical analysis demonstrates that the number of reader-to-reader collisions after a slot change is decreased by over 30%. The simulation analysis validates the theoretical results, and shows that PDCS reaches better performance than state-of-the-art reader-to-reader anti-collision protocol

Banknote identification through unique fluorescent properties

The use of printed banknotes is widespread despite cashless payment methods: for example, more than 27 billion euro banknotes are currently in circulation, and this amount is constantly increasing. Unfortunately, many false banknotes are in circulation, too. Central banks worlwide are continuously striving to reduce the counterfeiting. To fight against the criminal practice, a range of security features are added to banknotes, such as watermarks, micro-printing, holograms, and embossed characters. Beside these well-known characteristics, the colored fibers inside every banknote have strong potential as a security feature, but have so far been poorly exploited. The mere presence of colored fibers does not guarantee the banknote genuineness, as they can be drawn or printed by counterfeiters. However, their random position can be exploited to uniquely identify the banknote. This paper presents a technique for automatically recognizing fibers and efficiently storing their positions, considering realistic application scenarios. The classification accuracy and fault tolerance of the proposed method are theoretically demonstrated, thus showing its applicability regardless of banknote wear or any implementation issue. This is a major advantage with respect to state-of-the-art anti-counterfeit approaches. The proposed security method is strictly topical, as the European Central Bank plans to redesign euro banknotes by 2024

Recognizing the Type of Mask or Respirator Worn Through a CNN Trained with a Novel Database

Since the onset of the coronavirus pandemic, researchers from all over the world have been working on projects aimed at countering its advance. The authors of this paper want to go in this direction through the study of a system capable of recognizing the type of mask or respirator worn by a person. It can be used to implement automatic entry controls in high protection areas, where people can feel comfortable and safe. It can also be used to make sure that people who work daily in contact with particles, chemicals, or other impurities wear appropriate respiratory protection. In this paper, a proof-of-concept of this system will be presented. It has been realized by using a state-of-the-art Convolutional Neural Network (CNN), EfficientNet, which was trained on a novel database, called the Facial Masks and Respirators Database (FMR-DB). Unlike other databases released so far, it has an accurate classification of the most important types of facial masks and respirators and their degree of protection. It is also at the complete disposal of the scientific community

A Quantum Adaptation for the Morra Game and some of its Variants

The Morra game is quite old. Back in time, traces of it can be found in ancient Egypt, ancient Rome, and even China. It involves two players who, for a limited number of turns, must try to suppose the sum of the number personally chosen with the number chosen by the opponent. The rules are simple, but it is rather difficult to play at a high level as there are multiple cognitive, motor, and perceptual processes involved. The goal of this paper is to illustrate the process of implementing a quantum random player for the Morra game and some of its variants. This can be done by using a quantum number generator circuit to generate two numbers and a quantum adder to obtain the supposed sum. The advantage of this proposal is that, unlike the implementations of the Morra game on classical computers, which only allow the generation of pseudo-random numbers, true randomness can be obtained through quantum computing. In addition to the description of the entire algorithms, the source code of the implementations is provided to give everyone the freedom to easily test both the quantum implementation of the Morra game and the variants discussed in the paper

Tampering in RFID: A Survey on Risks and Defenses

RFID is a well-known pervasive technology, which provides promising opportunities for the implementation of new services and for the improvement of traditional ones. However, pervasive environments require strong efforts on all the aspects of information security. Notably, RFID passive tags are exposed to attacks, since strict limitations affect the security techniques for this technology. A critical threat for RFIDbased information systems is represented by data tampering, which corresponds to the malicious alteration of data recorded in the tag memory. The aim of this paper is to describe the characteristics and the effects of data tampering in RFID-based information systems, and to survey the approaches proposed by the research community to protect against it. The most important recent studies on privacy and security for RFID-based systems are examined, and the protection given against tampering is evaluated. This paper provides readers with an exhaustive overview on risks and defenses against data tampering, highlighting RFID weak spots and open issues

Producing green computing images to optimize power consumption in OLED-based displays

Energy consumption in Organic Light Emitting Diode (OLED) depends on the displayed contents. The power consumed by an OLED-based display is directly proportional to the luminance of the image pixels. In this paper, a novel idea is proposed to generate energy-efficient images, which consume less power when shown on an OLED-based display. The Blue color component of an image pixel is the most power-hungry i.e. it consumes more power as compared to the Red and Green color components. The main idea is to reduce the intensity of the blue color to the best possible level so that the overall power consumption is reduced while maintaining the perceptual quality of an image. The idea is inspired by the famous “Land Effect”, which demonstrates that it is possible to generate a full-color image by using only two color components instead of three. experiments are performed on the Kodak image database. The results show that the proposed method is able to reduce the power consumption by 18% on average and the modified images do not lose the perceptual quality. Social media platform, where users scroll over many images, is an ideal application for the proposed method since it will greatly reduce the power consumption in mobile phones during surfing social networking applications