2,235 research outputs found
Maximum-likelihood coherent-state quantum process tomography
Coherent-state quantum process tomography (csQPT) is a method of completely
characterizing a quantum-optical "black box" by probing it with coherent states
and performing homodyne measurements on the output [M. Lobino et al, Science
322, 563 (2008)]. We present a technique for csQPT that is fully based on
statistical inference, specifically, quantum expectation-maximization. The
method relies on the Jamiolkowski isomorphism and iteratively reconstructs the
process tensor in the Fock basis directly from the experimental data. This
approach permits incorporation of a priori constraints into the reconstruction
procedure, thereby guaranteeing that the resulting process tensor is physically
consistent. Furthermore, our method is easier to implement and requires a
narrower range of coherent states than its predecessors. We test its
feasibility using simulations on several experimentally relevant processes.Comment: 17 pages, 4 figure
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From spring to summer? Revolutionary change in Tunisia, Egypt and Libya
This article offers an analysis of the early stages of the revolutions that have been taking place in Tunisia, Egypt and Libya. Here we consider the early stages of the revolutions from winter 2010-11 up until the summer of 2012 and offers a comparative study of the experiences of the early stage of the revolutions in each case study. In particular this study considers the roles of six variables on the process of regime change and transition as follows: 1) duration of the uprising up to regime change; 2) the initial outcome of the revolution/uprising; 3) the number of deaths and casualties; 4) the post-regime change status of key members of the former governing elite; 5) the existence and nature of post-regime change elections; and 6) levels of international involvement. This study finds that in all three case studies, considering these variables offers insight into the nature and effect of the early stages of the revolutions. Furthermore, in each case there are key similarities in some of these variables but significant differences in others which suggest that the processes of transition are not directly comparable with each other. This article also offers some thoughts on how the early stages of these revolutions could affect the direction and pace of change in each state
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Libya after the civil war: regime change and democratisation
This article examines changes in Libyaâs internal security, politics, economy and international relations since the start of the revolution in February 2011. Our main argument is that in order to transition from authoritarianism to democracy significant change in each of these four, mutually reinforcing, areas is needed. Drawing on data collected through media analysis and field work, we offer a discussion of the nature of change in Libya and how far the country has democratised. We claim that significant changes in Libyaâs political system and foreign relations have taken place since 2011 that reinforce the process of democratisation. Within the political system these changes include the conduct of free and fair elections, the formation of new political parties, the reinforcement of civil rights and liberties, governmental accountability and the emergence of a participant political culture. Within foreign relations they include deeper cooperation with regional and international actors, reintegration into the Arab League, and rapprochement with Western states. However, we also observe that structural economic changes, in particular raising personal incomes and lowering poverty, and the normalisation of security provision are moving forward more slowly. We conclude that democratisation in Libya is taking place and there is a solid possibility that embedded democracy will emerge in Libya in the medium to long-term
Using a discrete choice experiment to estimate societal health state utility values
In this study we explore a novel application of the Discrete Choice Experiment (DCE) that resembles the Time Trade Off (TTO) task to estimate values on the health utility scale for the EQ-5D. The DCE is tested in a survey alongside the TTO in respondents largely representative of the Canadian general population. The study finds that the DCE is able to derive logical and consistent values for health states valued on the full health â dead scale. The DCE overcame some issues identified in the version of TTO currently used to value EQ-5D, notably whether to exclude respondents who fail to understand the task and incorporating values considered worse than dead without transformation. This has important implications for providing values that represent the preferences of all respondents
Analyzing supply response of fruit tree products in Tunisia: The case of peaches
In Tunisia, peaches have a significant place in the fruit tree sector. Planted areas have been expanding ever since the eighties as a result of irrigation water extension and the use of better yielding varieties. These factors resulted in high production levels and fruit exports thereof. However, important seasonal and annual variation of fruit supplies continues to characterize prices at both wholesale and consumption levels. To study the response of peach production an econometric model was developed. Modelling was carried out in two stages. First area variation was explained through new plantings and removals and second yield variation was analyzed. The methodological approach followed takes into account the characteristics and specificities related to perennial crops. Weak response of supply to variations in expected prices was obtained. Supply price elasticity was estimated about 0.13 suggesting a high degree of inelasticity.Supply response, modeling, price expectations, peaches, Demand and Price Analysis,
Pengembangan Model Pembelajaran Pendidikan Politik Berbasis Partisipasi Siswa Dalam Pkn (Studi Pada Siswa SMA Negeri 3 Sukoharjo)
This study aims to: (1) To develop a learning model based Political Education in civics student participation in accordance with the conditions of SMA Negeri 3 Sukoharjo. (2) Describe the steps Political Education learning models based on participation of students in Civics in accordance with the conditions of SMA Negeri 3 Sukoharjo. (3) Describe the feasibility of developing a learning model based on student participation Political Education in Civics in accordance with the conditions of SMA Negeri 3 Sukoharjo. This study uses the research or development of Research and Development. Data analysis is an interactive model of analysis of data reduction, data presentation and conclusion. Research procedures using the steps preliminary study phase, development and testing. Based on these results it can be concluded that: (1) High School Civics Teacher Interior 3 Sukoharjo desperately need civics learning models that optimize student participation in the learning of political education. These needs can be equipped with developing learning models that are tailored to the conditions of SMA Negeri 3 Sukoharjo. (2) The steps of Politics Partisipare learning model is as follows: (a) Planning Phase (b) Implementation Phase (c) Evaluation Phase. (3) Of all the due diligence has been carried out by researchers generate that the learning model is on average rated as excellent and worthy by a team of experts, teachers and students so as to promote student participation in politics with through civics education
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