Eales’ Disease: Case report

Eales’ disease is a retinal vasculopathy of unknown origin. Ischaemic step associated retinal perivasculitis. Neovascularisation step after the previous one, characterised by vitreous haemorrhage in relation with retinal neo vessels. This observation presents the first reported case of this pathology in Brazzaville. A man of 32 was followed for more than five episodes of vitreous haemorrhage over three years. These episodes had an average duration of two months, inter-spersed with complete clinical silence period of variable duration. During crises, visual acuity was under 2/10, and then it went back up to 10/10 spontaneously. Successive tests were normal: blood count, serologies (syphilis, HIV, Lyme), blood tests (converting enzyme, angiotensin II, calcium), tuberculin skin test, fluorescein angiography (FA), chest x-ray. The last episode was unusual, by the depth of visual impairment (light perception), by the existence of retinal neovascularisation (sea fan aspect). The outcome was favorable after retinal photocoagulation and corticotherapy

A Survey on Approximation Mechanism Design without Money for Facility Games

In a facility game one or more facilities are placed in a metric space to serve a set of selfish agents whose addresses are their private information. In a classical facility game, each agent wants to be as close to a facility as possible, and the cost of an agent can be defined as the distance between her location and the closest facility. In an obnoxious facility game, each agent wants to be far away from all facilities, and her utility is the distance from her location to the facility set. The objective of each agent is to minimize her cost or maximize her utility. An agent may lie if, by doing so, more benefit can be obtained. We are interested in social choice mechanisms that do not utilize payments. The game designer aims at a mechanism that is strategy-proof, in the sense that any agent cannot benefit by misreporting her address, or, even better, group strategy-proof, in the sense that any coalition of agents cannot all benefit by lying. Meanwhile, it is desirable to have the mechanism to be approximately optimal with respect to a chosen objective function. Several models for such approximation mechanism design without money for facility games have been proposed. In this paper we briefly review these models and related results for both deterministic and randomized mechanisms, and meanwhile we present a general framework for approximation mechanism design without money for facility games

Fast Neutron Profiling with Imazing Plate

開始ページ、終了ページ: 冊子体のページ付

Fast Neutron Profiling with Imaging Plate (2) - Response of IP with a Converter for Energy and the Converter Thickness -

開始ページ、終了ページ: 冊子体のページ付

Strategy-Proof Mechanism for Obnoxious Facility Location on a Line

LNCS v. 9198 entitled: Computing and Combinatorics: 21st International Conference, COCOON 2015, Beijing, China, August 4-6, 2015, ProceedingsIn the problem of obnoxious facility location, an obnoxious facility is located in an area. To maximize the social welfare, e.g., the sum of distances from all the agents to the facility, we have to get the true locations of each agent. However, each agent may misreport his/her location to stay far away from the obnoxious facility. In this paper, we design strategy-proof mechanisms on locating an obnoxious facility on a real line. Two objective functions, i.e., maximizing the sum of squares of distances (maxSOS) and maximizing the sum of distances (maxSum), have been considered. For maxSOS, a randomized strategy-proof mechanism with approximation ratio 5 / 3 is given, meanwhile the lower bound is proved to be at least 1.042. The lower bound of any randomized strategy-proof mechanisms w.r.t. maxSum is proved to be 1.077. Moreover, an extended model that each agent controls multiple locations is considered. For this model, we investigate deterministic and randomized strategy-proof mechanisms w.r.t. maxSum and maxSOS objectives, respectively. The deterministic mechanisms are shown to be tight for both objectives