Laboratory Experiment of Checkerboard Pupil Mask Coronagraph

We present the results of the first laboratory experiment of checkerboard shaped pupil binary mask coronagraphs using visible light, in the context of the R&D activities for future mid-infrared space missions such as the 3.5 m SPICA telescope. The primary aim of this work is to demonstrate the coronagraphic performance of checkerboard masks down to a $10^{-6}$ peak-to-peak contrast, which is required to detect self-luminous extra-solar planets in the mid-infrared region. Two masks, consisting of aluminum films on a glass substrates, were manufactured using nano-fabrication techniques with electron beam lithography: one mask was optimized for a pupil with a 30% central obstruction and the other was for a pupil without obstruction. The theoretical contrast for both masks was $10^{-7}$ and no adaptive optics system was employed. For both masks, the observed point spread functions were quite consistent with the theoretical ones. The average contrast measured within the dark regions was $2.7 {\times} 10^{-7}$ and $1.1 {\times} 10^{-7}$. The coronagraphic performance significantly outperformed the $10^{-6}$ requirement and almost reached the theoretical limit determined by the mask designs. We discuss the potential application of checkerboard masks for mid-infrared coronagraphy, and conclude that binary masks are promising for future high-contrast space telescopes.Comment: 6 pages, 6 figure

Inter Laboratory Experiment

談話

A Laboratory Experiment of Knowledge Diffusion Dynamics

This paper aims to study, by means of a laboratory experiment and a simulation model, some of the mechanisms which dominate the phenomenon of knowledge diffusion in the process that is called ‘interactive learning’. We examine how knowledge spreads in different networks in which agents interact by word of mouth. We define a regular network, a randomly generated network and a small world network structured as graphs consisting of agents (vertices) and connections (edges), situated on a wrapped grid forming a lattice. The target of the paper is to identify the key factors which affect the speed and the distribution of knowledge diffusion. We will show how these factors can be classified as follow: (1) learning strategies adopted by heterogeneous agents; (2) network architecture within which the interaction takes place; (3) geographical distribution of agents and their relative initial levels of knowledge. We shall also attempt to single out the relative effect of each of the above factors.Knowledge, Network, Small world, Experiment, Simulation.

Can Competition Spoil Reciprocity? - A Laboratory Experiment

This paper investigates how group membership and competition among trustors interact with trust and trustworthiness in a laboratory one-shot trust game. To analyze these effects, we apply a 2x2 design. We induce group membership by letting subjects play coordination games with clear focal points, leading to higher investments and trustworthiness. Introducing competition leads to a decrease in trustworthiness, especially among partners. We argue that once competition comes into play, trustees perceive trustors’ investments as the outcomes of a competitive bidding process rather than good intentions, which reduces reciprocity.trust, reciprocity, investment game, group membership, competition

Reciprocity towards groups : a laboratory experiment on the causes

Field studies of conflict report cycles of mutual revenge between groups, often linked to perceptions of intergroup injustice. We test the hypothesis that people are predisposed to reciprocate against groups. In a computerized laboratory experiment, subjects who were harmed by a partner’s uncooperative action reacted by harming other members of the partner’s group. This group reciprocity was only observed when one group was seen to be unfairly advantaged. Our results support a behavioral mechanism leading from perceived injustice to intergroup conflict. We discuss the relevance of group reciprocity to economic and political phenomena including conflict, discrimination and team competition

A laboratory experiment in calculus for the high school

Thesis (M.A.)--Boston Universit

Sabotage in Tournaments: Evidence from a Laboratory Experiment

Although relative performance schemes are pervasive in organizations reliable empirical data on induced sabotage behavior is almost non-existent. We study sabotage in tournaments in a controlled laboratory experiment and are able to confirm one of the key insights from theory: effort and sabotage increase with the wage spread. Additionally, we find that even in the presence of tournament incentives, agents react reciprocally to higher wages, which mitigates the sabotage problem. Destructive activities are reduced by explicitly calling them by their name 'sabotage'. Communication among principal and agents curbs sabotage due to agreements on flat prize structures and increased output.sabotage, tournament, reciprocity, relative performance scheme, experiment

Selective Circuits - Laboratory Experiment

Cílem této bakalářské práce je popsat rozdělení a chování selektivních obvodů a způsoby jejich realizace. Jsou zde uvedeny vztahy pro výpočet hodnot součástek vybraných kmitočtových filtrů RLC druhého řádu. Dále jsou zde popsány možnosti výběru součástek kmitočtových filtrů a výpočetní vztahy potřebné pro konstrukci cívek. Práce dále obsahuje popis a kompletní informace potřebné pro výrobu měřícího přípravku pro měření pásmových propustí RLC druhého řádu. V příloze této práce veškeré materiály potřebné pro realizaci laboratorní úlohy využívající navržený měřící přípravek.The aim of this thesis is to describe the distribution and behavior of selective circuits and methods for their implementation. There are formulas provided for the calculation of the frequency components of selected second-order RLC filters. It further describes the choice of filter frequency components and computing relationships needed for the construction of coils. The work also includes a description and complete information needed for making measurements of the measurement of the RLC band-pass. The annex to this work includes all the materials needed for implementation of laboratory tasks designed to measure using the product.