3,889 research outputs found

    Entangling two distant non-interacting microwave modes

    Full text link
    We propose a protocol able to prepare two remote and initially uncorrelated microwave modes in an entangled stationary state, which is certifiable using only local optical homodyne measurements. The protocol is an extension of continuous variable entanglement swapping, and exploits two hybrid quadripartite opto-electro-mechanical systems in which a nanomechanical resonator acts as a quantum interface able to entangle optical and microwave fields. The proposed protocol allows to circumvent the problems associated with the fragility of microwave photons with respect to thermal noise and may represent a fundamental tool for the realization of quantum networks connecting distant solid-state and superconducting qubits, which are typically manipulated with microwave fields. The certifying measurements on the optical modes guarantee the success of entanglement swapping without the need of performing explicit measurements on the distant microwave fields.Comment: 7 pages, 3 figures; to appear in the special issue "Quantum and Hybrid Mechanical Systems - From Fundamentals to Applications" in Annalen der Physi

    The art of spacecraft design: A multidisciplinary challenge

    Get PDF
    Actual design turn-around time has become shorter due to the use of optimization techniques which have been introduced into the design process. It seems that what, how and when to use these optimization techniques may be the key factor for future aircraft engineering operations. Another important aspect of this technique is that complex physical phenomena can be modeled by a simple mathematical equation. The new powerful multilevel methodology reduces time-consuming analysis significantly while maintaining the coupling effects. This simultaneous analysis method stems from the implicit function theorem and system sensitivity derivatives of input variables. Use of the Taylor's series expansion and finite differencing technique for sensitivity derivatives in each discipline makes this approach unique for screening dominant variables from nondominant variables. In this study, the current Computational Fluid Dynamics (CFD) aerodynamic and sensitivity derivative/optimization techniques are applied for a simple cone-type forebody of a high-speed vehicle configuration to understand basic aerodynamic/structure interaction in a hypersonic flight condition

    The Newest African-Americans?: Somali Struggles for Belonging

    Get PDF

    In Limbo: Dependency, Insecurity, and Identity amongst Somali Refugees in Dadaab Camps

    Get PDF

    Les bouleversements induits par la guerre civile en Somalie : castes marginales et minorités

    Get PDF
    Par suite de l'incapacité à aboutir à une solution politique au conflit civil qui déchire la société somalienne depuis 1991, une partie importante de la population (waable et ka baxsanayaal bantou), traditionnellement discriminée par les deux grandes classes nobles somali (waranle et wadaad/guerriers et hommes de la connaissance religieuse), accède à une reconnaissance internationale de son statut particulier et en tient comme acquis les principes. On peut considérer qu'on assiste actuellement à un bouleversement de certaines données sociales en Somalie et principalement des faits structurant la nation et la normalité. (Résumé d'auteur

    Reversible optical to microwave quantum interface

    Full text link
    We describe a reversible quantum interface between an optical and a microwave field using a hybrid device based on their common interaction with a micro-mechanical resonator in a superconducting circuit. We show that, by employing state-of-the-art opto-electro-mechanical devices, one can realise an effective source of (bright) two-mode squeezing with an optical idler (signal) and a microwave signal, which can be used for high-fidelity transfer of quantum states between optical and microwave fields by means of continuous variable teleportation.Comment: 5 + 3 pages, 5 figure

    In Limbo: Dependency, Insecurity, and Identity amongst Somali Refugees in Dadaab Camps

    Get PDF
    The Somali civil war of 1991 left thousands of refugees scattered in neighbouring countries. This article examines the situation of the 130,000 Somalis in their second decade in Dadaab camps in Kenya, with a particular focus on the role and responsibilities of the refugee regime and the host state. It is argued that these camps are characterized by deprivations of both material and physical security. Research found that refugees’ dependency on inadequate aid is due to lack of alternative livelihoods rather than “dependency syndrome.” However, participants expressed diminished “self-esteem” resulting from their prolonged encampment. Finally, the paper presents a critique of the failure to explore solutions for protracted refugee situations on the part of the international refugee regime.La guerre civile de 1991 en Somali a laissé des milliers de réfugiés éparpillés dans les pays avoisinants. Cet article examine le sort des 130,000 somaliens qui sont à leur deuxième décennie dans les camps de Dadaab au Kenya, avec une emphase particulière sur le rôle et les responsabilités de la convention sur les réfugiés et du pays hôte. L’article soutient que ces camps sont caractérisés par un manque de sécurité tant au niveau physique que matériel. Des études ont démontré que la dépendance des réfugiés sur de l’assistance – quoique cette assistance est elle-même insuffisante – découle d’une absence de voies alternatives pour gagner sa vie plutôt d’un syndrome de dépendance. Toutefois, les participants ont exprimé un sens diminué d’estime de soi, résultant de leur séjour prolongé dans le camp. Pour terminer. L’article examine de façon critique le fait que la convention internationale sur les réfugiés ait failli dans son devoir de rechercher des solutions alternatives pour des gens se retrouvant comme réfugiés pour un laps de temps prolongé

    A test of general strain theory with Somali refugee youth: a consideration of police, teacher, and family strains

    Full text link
    This three-paper dissertation tests whether General Strain Theory (GST) can be helpful in explaining the relationship between strains experienced by refugee youth and youth’s anti-social behaviors such as delinquency and radicalization to violence and what factors mediate the relationship between strain and crime. Additionally, it uses mixed methods combining community meaning-making with quantitative research methods to provide multiple lenses to the issue of youth and negative outcomes. The first chapter presents the context in which Somali refugee youth experiences should be examined as well as relevant literature. The second chapter examines if GST can help us understand the experiences of Somali youth and delinquencies. It examines if three strains (procedural injustice, teacher punishment, and family conflict) are significantly related to crimes against people among this population and if this relationship is mediated by mental health symptoms and marginalization. The results show that both procedural justice and teacher punishment were able to predict crimes against people but the relationship between procedural injustice and crimes against people was fully mediated by mental health symptoms and by marginalization while the relationship between teacher mistreatment and crime remained significant even when mental health symptoms and marginalization were added to the equation. Surprisingly, while the family conflict was highly correlated with both marginalization and mental health symptoms, it was not significantly related to crimes against people. The third chapter applies GST to radicalization to violence among Somali youth. It examines whether three strains (procedural injustice, teacher punishment, and family conflict) predict youth radicalization to violence and whether this relationship is mediated by individual-level factors such as mental health, marginalization and gang attitudes. The analysis shows that only procedural injustice is significantly related to radicalization to violence and that both marginalization and gang attitudes fully mediated the relationship while mental health partially mediated it. The final chapter uses Interpretive Phenomenological Analysis (IPA) to examine community meaning making around youth radicalization. Qualitative interview results show that community members were able to identify important structural, cultural and individual level factors that led to youth radicalization and that many of the factors that they identified such as police and teacher mistreatment and gang presence where similar to the findings in the quantitative research
    • …
    corecore