Theory of quantum frequency translation of light in optical fiber: application to interference of two photons of different color

We study quantum frequency translation and two-color photon interference enabled by the Bragg scattering four-wave mixing process in optical fiber. Using realistic model parameters, we computationally and analytically determine the Green function and Schmidt modes for cases with various pump-pulse lengths. These cases can be categorized as either "non-discriminatory" or "discriminatory" in regards to their propensity to exhibit high-efficiency translation or high-visibility two-photon interference for many different shapes of input wave packets or for only a few input wave packets, respectively. Also, for a particular case, the Schmidt mode set was found to be nearly equal to a Hermite-Gaussian function set. The methods and results also apply with little modification to frequency conversion by sum-frequency conversion in optical crystals

The linear Fokker-Planck equation for the Ornstein-Uhlenbeck process as an (almost) nonlinear kinetic equation for an isolated N-particle system

It is long known that the Fokker-Planck equation with prescribed constant coefficients of diffusion and linear friction describes the ensemble average of the stochastic evolutions in velocity space of a Brownian test particle immersed in a heat bath of fixed temperature. Apparently, it is not so well known that the same partial differential equation, but now with constant coefficients which are functionals of the solution itself rather than being prescribed, describes the kinetic evolution (in the infinite particle limit) of an isolated N-particle system with certain stochastic interactions. Here we discuss in detail this recently discovered interpretation.Comment: Minor revisions and corrections (including the title

Operation Diagnosis for Buildings Connecting Building Management Systems with Energy Management Systems

Reducing energy consumption of buildings is a good contribution to protect the environment and to reduce costs. The first and most important step to operate a building most efficiently is to make aware of most of the technical parameters. Connecting or installing a Building Automation Sys-tem with an Energy Management System helps to analyze the flow of material, build up an integrated Alarm Management and create an excellent documentation of the installed base. To pick the best of each and connect the two professional systems is the principle for a successful Operation Diagnosis

Owl and Lizard: Patterns of Head Pose and Eye Pose in Driver Gaze Classification

Accurate, robust, inexpensive gaze tracking in the car can help keep a driver safe by facilitating the more effective study of how to improve (1) vehicle interfaces and (2) the design of future Advanced Driver Assistance Systems. In this paper, we estimate head pose and eye pose from monocular video using methods developed extensively in prior work and ask two new interesting questions. First, how much better can we classify driver gaze using head and eye pose versus just using head pose? Second, are there individual-specific gaze strategies that strongly correlate with how much gaze classification improves with the addition of eye pose information? We answer these questions by evaluating data drawn from an on-road study of 40 drivers. The main insight of the paper is conveyed through the analogy of an "owl" and "lizard" which describes the degree to which the eyes and the head move when shifting gaze. When the head moves a lot ("owl"), not much classification improvement is attained by estimating eye pose on top of head pose. On the other hand, when the head stays still and only the eyes move ("lizard"), classification accuracy increases significantly from adding in eye pose. We characterize how that accuracy varies between people, gaze strategies, and gaze regions.Comment: Accepted for Publication in IET Computer Vision. arXiv admin note: text overlap with arXiv:1507.0476

Major flaws in conflict prevention policies towards Africa : the conceptual deficits of international actors’ approaches and how to overcome them

Current thinking on African conflicts suffers from misinterpretations oversimplification, lack of focus, lack of conceptual clarity, state-centrism and lack of vision). The paper analyses a variety of the dominant explanations of major international actors and donors, showing how these frequently do not distinguish with sufficient clarity between the ‘root causes’ of a conflict, its aggravating factors and its triggers. Specifically, a correct assessment of conflict prolonging (or sustaining) factors is of vital importance in Africa’s lingering confrontations. Broader approaches (e.g. “structural stability”) offer a better analytical framework than familiar one-dimensional explanations. Moreover, for explaining and dealing with violent conflicts a shift of attention from the nation-state towards the local and sub-regional level is needed.Aktuelle Analysen afrikanischer Gewaltkonflikte sind häufig voller Fehlinterpretationen (Mangel an Differenzierung, Genauigkeit und konzeptioneller Klarheit, Staatszentriertheit, fehlende mittelfristige Zielvorstellungen). Breitere Ansätze (z. B. das Modell der Strukturellen Stabilität) könnten die Grundlage für bessere Analyseraster und Politiken sein als eindimensionale Erklärungen. häufig differenzieren Erklärungsansätze nicht mit ausreichender Klarheit zwischen Ursachen, verschärfenden und auslösenden Faktoren. Insbesondere die richtige Einordnung konfliktverlängernder Faktoren ist in den jahrzehntelangen gewaltsamen Auseinandersetzungen in Afrika von zentraler Bedeutung. Das Diskussionspapier stellt die große Variationsbreite dominanter Erklärungsmuster der wichtigsten internationalen Geber und Akteure gegenüber und fordert einen Perspektivenwechsel zum Einbezug der lokalen und der subregionalen Ebene für die Erklärung und Bearbeitung gewaltsamer Konflikte

The Quantum Modular Group in (2+1)-Dimensional Gravity

The role of the modular group in the holonomy representation of (2+1)-dimensional quantum gravity is studied. This representation can be viewed as a "Heisenberg picture", and for simple topologies, the transformation to the ADM "Schr{\"o}dinger picture" may be found. For spacetimes with the spatial topology of a torus, this transformation and an explicit operator representation of the mapping class group are constructed. It is shown that the quantum modular group splits the holonomy representation Hilbert space into physically equivalent orthogonal ``fundamental regions'' that are interchanged by modular transformations.Comment: 23 pages, LaTeX, no figures; minor changes and clarifications in response to referee (basic argument and conclusions unaffected

Living in several languages: Language, gender and identities

Living in several languages encompasses experiencing and constructing oneself differently in each language. The research study on which this article is based takes an intersectional approach to explore insider accounts of the place of language speaking in individuals’ constructions of self, family relationships and the wider context. Twenty-four research interviews and five published autobiographies were analysed using grounded theory, narrative and discursive analysis. A major finding was that learning a new language inducted individuals into somewhat ‘stereotyped’ gendered discourses and power relations within the new language, while also enabling them to view themselves differently in the context of their first language. This embodied process could be challenging and often required reflection and discursive work to negotiate the dissimilarities, discontinuities and contradictions between languages and cultures. However, the participants generally claimed that their linguistic multiplicity generated creativity. Women and men used their language differences differently to ‘perform their gender’. This was particularly evident in language use within families, which involved gendered differences in the choice of language for parenting – despite the fact that both men and women experience their first languages as conveying intimacy in their relationships with their children. The article argues that the notion of ‘mother tongue’ (rather than ‘first language’) is unhelpful in this process as well as in considering the implications of living in several languages for systemic therapy

Resting tachycardia, a warning sign in anorexia nervosa: case report

BACKGROUND: Among psychiatric disorders, anorexia nervosa has the highest mortality rate. During an exacerbation of this illness, patients frequently present with nonspecific symptoms. Upon hospitalization, anorexia nervosa patients are often markedly bradycardic, which may be an adaptive response to progressive weight loss and negative energy balance. When anorexia nervosa patients manifest tachycardia, even heart rates in the 80–90 bpm range, a supervening acute illness should be suspected. CASE PRESENTATION: A 52-year old woman with longstanding anorexia nervosa was hospitalized due to progressive leg pain, weakness, and fatigue accompanied by marked weight loss. On physical examination she was cachectic but in no apparent distress. She had fine lanugo-type hair over her face and arms with an erythematous rash noted on her palms and left lower extremity. Her blood pressure was 96/50 mm Hg and resting heart rate was 106 bpm though she appeared euvolemic. Laboratory tests revealed anemia, mild leukocytosis, and hypoalbuminemia. She was initially treated with enteral feedings for an exacerbation of anorexia nervosa, but increasing leukocytosis without fever and worsening left leg pain prompted the diagnosis of an indolent left lower extremity cellulitis. With antibiotic therapy her heart rate decreased to 45 bpm despite minimal restoration of body weight. CONCLUSIONS: Bradycardia is a characteristic feature of anorexia nervosa particularly with significant weight loss. When anorexia nervosa patients present with nonspecific symptoms, resting tachycardia should prompt a search for potentially life-threatening conditions