3,837 research outputs found

    Mean Field Theory For Non-Equilibrium Network Reconstruction

    Full text link
    There has been recent progress on the problem of inferring the structure of interactions in complex networks when they are in stationary states satisfying detailed balance, but little has been done for non-equilibrium systems. Here we introduce an approach to this problem, considering, as an example, the question of recovering the interactions in an asymmetrically-coupled, synchronously-updated Sherrington-Kirkpatrick model. We derive an exact iterative inversion algorithm and develop efficient approximations based on dynamical mean-field and Thouless-Anderson-Palmer equations that express the interactions in terms of equal-time and one time step-delayed correlation functions.Comment: new version, accepted in PRL. For the Supp. Mat. (ref. 11), please contact the author

    Hair histology as a tool for forensic identification of some domestic animal species

    Full text link
    Animal hair examination at a criminal scene may provide valuable information in forensic investigations. However, local reference databases for animal hair identification are rare. In the present study, we provide differential histological analysis of hair of some domestic animals in Upper Egypt. For this purpose, guard hair of large ruminants (buffalo, camel and cow), small ruminants (sheep and goat), equine (horse and donkey) and canine (dog and cat) were collected and comparative analysis was performed by light microscopy. Based on the hair cuticle scale pattern, type and diameter of the medulla, and the pigmentation, characteristic differential features of each animal species were identified. The cuticle scale pattern was imbricate in all tested animals except in donkey, in which coronal scales were identified. The cuticle scale margin type, shape and the distance in between were characteristic for each animal species. The hair medulla was continuous in most of the tested animal species with the exception of sheep, in which fragmental medulla was detected. The diameter of the hair medulla and the margins differ according to the animal species. Hair shaft pigmentation were not detected in all tested animals with the exception of camel and buffalo, in which granules and streak-like pigmentation were detected. In conclusion, the present study provides a first-step towards preparation of a complete local reference database for animal hair identification that can be used in forensic investigations.Comment: 8 pages, 3 Figure

    Coupling of pinned magnetic moments in an antiferromagnet to a ferromagnet and its role for exchange bias

    Get PDF
    The interaction between uncompensated pinned magnetic moments within an antiferromagnetic (AFM) layer and an adjacent ferromagnetic (FM) layer responsible for the existence of exchange bias is explored in epitaxially grown trilayers of the form FM2/AFM/FM1 on Cu3Au(0 0 1) where FM1 is ~12 atomic monolayers (ML) Ni, FM2 is 21–25 ML Ni, and AFM is 27 ML or 50 ML Ni~25Mn~75. Field cooling for parallel or antiparallel alignment of the out-of-plane magnetizations of the two FM layers does not make a difference for the temperature-dependent coercivity (H C), magnitude of exchange bias field (H eb), AFM ordering temperature (T AFM), and blocking temperature for exchange bias (T b). We explain this by a model in which the uncompensated pinned magnetic moments distributed within the volume of the AFM layer interact with both of the FM layers, albeit with different strength. Parallel and antiparallel coupling between the magnetization of the pinned moments and the FM layers equally exists. This leads to the experimentally observed independence of H C, H eb, as well as of T AFM and T b on the magnetization direction of the FM layers during field cooling. These results provide new and detailed insight into revealing the subtle and complex nature of the exchange bias effect

    Softboiled Speech: A Contrastive Analysis of Death Euphemisms in Egyptian Arabic and Chinese

    Get PDF
    This contrastive study is geared towards investigating the euphemistic language of death in Egyptian Arabic and Chinese The results indicate that euphemisms are universal since they exist in every language and no human communication is without euphemisms Both Egyptian and Chinese native speakers regard the topic of death as a taboo Therefore they handle it with care Egyptian Arabic and Chinese employ euphemistic expressions to avoid mentioning the topic of death However Chinese has a large number of death euphemisms as compared with the Egyptian Arabic ones The results also show that death euphemisms are structurally and basically employed in both Egyptian Arabic and Chinese in metonymy as a linguistic device and a figure of speech Moreover they employ conceptual metaphor to substitute the taboo topic of deat

    Growth-mode investigation of epitaxial EuS on InAs(100)

    Get PDF
    A persistent challenge in the field of spintronics is the search for suitable materials that enable the circumvention of the impedance mismatch preventing efficient spin-injection from metallic ferromagnetic conductors into semiconductors. One promising material is europium sulfide (EuS), a ferromagnetic semiconductor below the Curie temperature of 16.5 K. Investigation and optimization of the conditions required for high-quality growth of epitaxial EuS films on suitable substrates are thus of particular interest for the creation of efficient devices. We present the results of a growth-mode study employing atomic force microscopy and spot-profile analysis low-energy electron diffraction (SPA-LEED) of epitaxial EuS thin films deposited by electron-beam evaporation on InAs(100) substrates with varying combinations of, respectively, growth and annealing temperatures, Tg and Ta, from room temperature to 400 °C. We observed Stranski-Krastanov-like growth featuring low-roughness surfaces with root mean square values between 0.4 – 0.9 nm for all temperature combinations. An increased tendency for nucleation into grains and islands was observed for higher Ta from 300 – 400 °C. The corresponding nucleation mode, defined by varying degrees of 2D and 3D nucleation, was dependent on Tg. A 2D island growth mode was observed for Tg = 150 °C and Ta = 400 °C featuring a sharp and bright SPA-LEED pattern. This suggests the formation of a highly ordered, smooth surface for these growth conditions thereby providing a good starting point for optimization attempts for potential future devices

    Advances in Surgical and Anesthetic Techniques for Cochlear Implantation

    Get PDF
    Cochlear implantation (CI) is usually performed under general anesthesia using the classic surgical approach, the mastoidectomy posterior tympanotomy approach (MPTA), which was originally described by William House in 1961. Many alternative surgical approaches have been described for CI. Robotic image-guided cochlear implantation has also been described as a new advance in CI. Also, in some situations, CI can be performed under conscious sedation with local anesthesia (CS-LA) instead of general anesthesia (GA). With the ongoing advance in CI devices and surgical techniques, CI surgery nowadays could preserve hearing in ears with preoperative residual hearing. This chapter describes different approaches and techniques in CI surgery, whether classic or alternative technique, with special attention to advantages and disadvantages of each approach or technique. Also this chapter describes, in surgical points of view, the anesthetic techniques in CI, whether GA or CS-LA, with focus on indications, advantages, and disadvantages of CS-LA in CI

    Honeyword Generation Using a Proposed Discrete Salp Swarm Algorithm

    Get PDF
    إن كلمات العسل (Honeywords) هي كلمات مرور مزيفة مرافقة لكلمة المرور الحقيقية والتي تدعى كلمة السكر. يعد نظام كلمات مرور العسل نظامًا فعالاً لاكتشاف اختراق كلمات المرور مصمم لاكتشاف اختراق كلمة المرور بسهولة من أجل تحسين أمان كلمات المرور المشفرة. لكل مستخدم ، سيكون لملف كلمة المرور الخاص بنظام الكلمات العسلية كلمة مرور واحدة حقيقية مشفرة مصحوبة بالعديد من كلمات المرور المزيفة المشفرة. إذا قام شخص دخيل بسرقة ملف كلمات المرور من النظام ونجح في اختراق كلمات المرور محاولا تسجيل الدخول إلى حسابات المستخدمين ، فسيكتشف نظام كلمات المرور هذه المحاولة من خلال مدقق العسل. (Honeychecker) مدقق العسل هو خادمًا إضافيًا يميز كلمة المرور الحقيقية عن كلمات المرور المزيفة ويطلق إنذارًا إذا قام شخص دخيل بتسجيل الدخول باستخدام كلمة مرور العسل. تم اقتراح العديد من طرق توليد كلمات العسل خلال البحوث السابقة، مع وجود قيود على عمليات إنشاء كلمات العسل الخاصة بهم ، ونجاح محدود في توفير جميع ميزات كلمات العسل المطلوبة ، والتعرض للعديد من مشكلات كلمات العسل. سيقدم هذا العمل طريقة جديدة لتوليد كلمات العسل تستخدم خوارزمية سرب عنب البحر المتقطعة. خوارزمية سرب عنب البحر هي خوارزمية تحسين مستوحاة من الأحياء تحاكي سلوك سرب عنب البحر في بيئتها الطبيعية. تم استخدام  خوارزمية سرب عنب البحر لحل مجموعة متنوعة من مشاكل التحسين. ستعمل طريقة توليد الكلمات العسلية المقترحة على تحسين عملية توليد كلمات العسل وتحسين ميزات كلمات العسل والتغلب على عيوب التقنيات السابقة. ستوضح هذه الدراسة العديد من الاستراتيجيات السابقة لتوليد الكلمات العسلية، ووصف الطريقة المقترحة، وفحص النتائج التجريبية، ومقارنة طريقة إنتاج كلمات العسل الجديدة بالطرق السابقة.Honeywords are fake passwords that serve as an accompaniment to the real password, which is called a “sugarword.” The honeyword system is an effective password cracking detection system designed to easily detect password cracking in order to improve the security of hashed passwords. For every user, the password file of the honeyword system will have one real hashed password accompanied by numerous fake hashed passwords. If an intruder steals the password file from the system and successfully cracks the passwords while attempting to log in to users’ accounts, the honeyword system will detect this attempt through the honeychecker. A honeychecker is an auxiliary server that distinguishes the real password from the fake passwords and triggers an alarm if intruder signs in using a honeyword. Many honeyword generation approaches have been proposed by previous research, all with limitations to their honeyword generation processes, limited success in providing all required honeyword features, and susceptibility to many honeyword issues. This work will present a novel honeyword generation method that uses a proposed discrete salp swarm algorithm. The salp swarm algorithm (SSA) is a bio-inspired metaheuristic optimization algorithm that imitates the swarming behavior of salps in their natural environment. SSA has been used to solve a variety of optimization problems. The presented honeyword generation method will improve the generation process, improve honeyword features, and overcome the issues of previous techniques. This study will demonstrate numerous previous honeyword generating strategies, describe the proposed methodology, examine the experimental results, and compare the new honeyword production method to those proposed in previous research
    corecore