Students’ Free Speech Rights Shed At The Cyber Gate

Education is one of the most important functions of the government. Because public schools are under the control of state and local authorities, the administrators and teachers of these schools are subject to requirements established in the United States Constitution. For example, for more than thirty years, the Supreme Court has supported the due process rights of students facing a deprivation of liberty and property interests in education

Forgive or Buy Back: An Experimental Study of Debt Relief

A large share of the debt claims owed by the world’s poorest countries has been cancelled through the HIPC (highly indebted poor countries) debt relief initiative. It is believed that, with less debt burden, the HIPC will be able to devote more resources to investment and thus promote their own growth and benefit their creditors in the long run. But does debt forgiveness really provide the best incentive for those countries who suffers from debt overhang? In this paper, we adopt experimental methods to study the impact of two different schemes for relieving debt. The two schemes we consider here are debt forgiveness and debt buyback, with the latter being more market-based since it allows indebted countries to repurchase their own debt on the secondary market at a discount. We find that creditors tend to reduce more debt when the relief takes the form of debt forgiveness than that of buyback. Debtors under the scheme of forgiveness are not significantly more reciprocal than those of buyback. After controlling for the amount of debt relief, creditors are significantly worse off under forgiveness whereas debtors are indifferent between the two schemes. Overall, debt forgiveness yields less desirable outcomes than debt buybacks.Laboratory Experiments

Competition vs. communication: An experimental study on restoring trust

International audienc

Nonspeculative bubbles in experimental asset markets: Lack of common knowledge of rationality vs. actual irrationality

We report the results of an experiment designed to study the role of speculation in the formation of bubbles and crashes in laboratory asset markets. In a setting in which speculation is not possible, bubbles and crashes are observed. The results suggest that the departures from fundamental values are not caused by the lack of common knowledge of rationality leading to speculation, but rather by behavior that itself exhibits elements of irrationality. Much of the trading activity that accompanies bubble formation, in markets where speculation is possible, is due to the fact that there is no other activity available for participants in the experiment

Post assembly process development for Monolithic OptoPill integration on silicon CMOS

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.Includes bibliographical references (leaves 108-110).Monolithic OptoPill integration by means of recess mounting is a heterogeneous technique employed to integrate III-V photonic devices on silicon CMOS circuits. The goal is to create an effective fabrication process that enables the volume production of high performance optoelectronic integrated circuits (OEICs). This thesis focuses on the development of post-assembly processes and technologies, in which InGaAs/InP P-i-N photodiodes were integrated as long wavelength photodetectors with an optical clock receiver circuit. Fabrication procedures, challenges experienced, and results accomplished are presented for each process step including the formation of alloyed and non-alloyed ohmic contacts on n-type and p-type InGaAs contact layers, active area definition by dry-etching InGaAs/InP with ECR-enhanced RIE, BCB passivation and planarization, via opening by dry-etching BCB with RIE, and top contact metallization. In conjunction, an InP-based test heterostructure was fabricated into discrete photodiodes. Decoupling the fabrication and benchmarking of III-V photonic device from the Si-CMOS electronic circuit allowed for the independent electrical and optical characterization of the photodetectors. Measurements and analysis of the P-i-N photodiodes will assist the forthcoming analysis of the final OEIC. Preliminary results and discussions of the calibration sample are presented in this thesis.by Yi-Shu Vivian Lei.S.M

Desarrollo y validación de una escala PLEs desde la perspectiva del alumno y el aprendizaje en la educación terciaria

The study's goal is to create and validate a Personal Learning Environment Scale (PLEs) from the learner and learning perspective (named PLEsS-LL) to ensure effective learning in Chinese tertiary education. 657 undergraduates participated in the study after completing scale development steps. Six factors were extracted from the PLEsS-LL using Exploratory Factor Analysis (EFA). Confirmatory Factor Analysis (CFA) supported the six-factor scale with 22 items. Furthermore, the PLEsS-LL was redesigned as a questionnaire to assess learners' readiness for PLE learning. The findings indicated that participants were comfortable learning in PLEs in general. They were mostly positive in terms of learning motivation and problem-solving abilities. They did, however, report less confidence in self-directed learning. Meanwhile, male participants outperformed female participants in all categories except learning motivation. The reasons were explained, and suggestions for future PLE design were made. The PLEsS-LL could be used as a resource or guide for learner preparation in the PLE context in higher education around the world.El objetivo del estudio es crear y validar una Escala de Entornos Personales de Aprendizaje (PLEsS) desde la perspectiva del alumno y el aprendizaje (llamada PLEsS-LL) para garantizar un aprendizaje efectivo en la educación terciaria china. 657 estudiantes universitarios participaron en el estudio después de completar los pasos de desarrollo de escala. Se extrajeron seis factores del PLEsS-LL mediante Análisis Factorial Exploratorio (EFA). El Análisis Factorial Confirmatorio (AFC) apoyó la escala de seis factores con 22 ítems.  Además, el PLEsS-LL fue rediseñado como un cuestionario para evaluar la preparación de los alumnos para el aprendizaje PLE. Los hallazgos indicaron que los participantes se sentían cómodos al aprender en PLE en general. En su mayoría fueron positivos en términos de motivación de aprendizaje y habilidades para resolver problemas. Sin embargo, informaron menos confianza en el aprendizaje autodirigido. Mientras tanto, los participantes masculinos superaron a las participantes femeninas en todas las categorías, excepto en la motivación de aprendizaje. Se explicaron las razones y se hicieron sugerencias para el diseño futuro de PLE. El PLEsS-LL podría utilizarse como un recurso o guía para la preparación del alumno en el contexto de los PLEs en la educación superior de todo el mundo

Synergistic effects of polypropylene and glass fiber on mechanical properties and durability of recycled aggregate concrete

To better understand the synergistic effects of combined fibers on mechanical properties and durability of recycled aggregate concrete (RAC), different types of fibers with various lengths and mass ratios were adopted in this study. Experimental investigations were conducted to study the 28-day compressive strength and strength loss after exposed to salt-solution freeze–thaw cycles and the coupled action of mechanical loading and salt-solution freeze–thaw cycles. The microstructure was also characterized to evaluate the mechanism of this synergistic effect. To determine the effectiveness of the combined fibers on improving the mechanical properties and durability of RAC, the synergistic coefficient was proposed and applied for various combinations of fibers. The results indicate that the incorporation of fibers slightly decreased the 28-day compressive strength of RAC, but combining different sizes and types of fibers can mitigate this negative effect. Moreover, the incorporation of fibers greatly improves the freeze–thaw resistance of RAC. The combining different fibers exhibited a synergistic effect on the enhancement in properties of RAC, which could not be predicted with only one simplistic rule of fibre mixtures. In addition, microstructural characterization shows that the bonding strength of the interfacial transition zone (ITZ) between the fiber and cement matrix is mainly determined by the chemical bonding force which is due to the hydration reaction between fiber surface and cement matrix

Asset Bubbles and Rationality: Additional Evidence from Capital Gains Tax Experiments

[Introduction] The remarkable phenomenon of bubbles and crashes in laboratory asset markets was first discovered and reported in Smith et al (1988). Subsequent research inquired about the robustness of the phenomenon and how it might be explained. One interpretation of the data is that public knowledge of rationality is lacking in the subjects, which leads to a type of individually rational, bubble creating speculation as part of an attempt to acquire capital gains. A different interpretation is that subjects begin with a type of confusion or mistaken understanding about this particular environment and that such “irrationality” at the individual level initiates the bubble, which could be sustained by a lack of common knowledge of rationality even after all confusion becomes removed during the process of participating in the market. This paper explores these two ideas through the study of experiments in which a capital gains tax is imposed that makes speculation for capital gains unprofitable except under extreme circumstances

Performance enhancement of permeable asphalt mixtures with recycled aggregate for concrete pavement application

The incorporation of recycled concrete aggregate (RCA) in permeable asphalt mixtures (PAMs) is an efficient method of utilizing construction demolished waste. It not only conforms to the trend of building sponge cities, but also alleviates the problem of overexploitation of natural aggregate resources. As the performance of PAM containing recycled aggregate is not comparable to natural aggregate, modification treatments and the addition of hybrid fibers are adopted as two enhancement methods to improve the performance of PAM with RAC in this study. It is found that replacing natural aggregate with recycled aggregate increases the optimum asphalt content (OAC) but decreases the residual stability. The OAC is increased by 45% when the RCA ratio is 100%, whereas applying silicone resin can give a 16.2% decrease in the OAC. Enhancing RCA with silicone resin can increase the water stability to be comparable with natural aggregate. Moreover, with modification treatment using calcium hydroxide solution, the mechanical strength of PAM is enhanced to even higher than that of natural coarse aggregate mixture alone. Improvements in both mechanical strength and water stability are also achieved by strengthening recycled aggregate with cement slurry, although the performance is less effective than using silicone resin. With the increase in the content of RCA, the permeability coefficients of PAM first decrease and then exhibit an increasing trend. The results indicate that the PAM with RCA and modification treatments can perform satisfactorily as a pavement material in practice. Applying probable modification, PAM incorporating RCA meets the criteria for use in concrete pavement applications