The effect of spacer length on the polymerization of diacetylenes in sams on gold surfaces

The influence of the molecular architecture of diacetylene disulfides on the structure and polymerizability of self assembled monolayers on gold was investigated. The position of the diacetylene group was varied systematically by adjusting the length of the tail and the spacer. For the structures studied, the longer the tail, the higher the akyl chain crystallinity as sensed by IR spectroscopy, and the higher the polymerization efficiency as probed by resonance Raman spectroscopy. The influence of the spacer on the polymerizability is more complicated. It is conjectured that the spacer reduces the lattice strain due to the misfit of the arrangement of the anchor groups and the arrangement of the diacetylene units and the polydiacetylene backbone, respectively. Simple modeling reveals that the number of the methylene units (odd or even) and the overall length both influence the arrangement. The highest polymerization efficiency is found for the longest, odd numbered spacer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106993/1/19991420105_ftp.pd

Phonon emission and absorption in the fractional quantum Hall effect

We investigate the time dependent thermal relaxation of a two-dimensional electron system in the fractional quantum Hall regime where ballistic phonons are used to heat up the system to a non-equilibrium temperature. The thermal relaxation of a 2DES at $\nu=1/2$ can be described in terms of a broad band emission of phonons, with a temperature dependence proportional to $T^4$. In contrast, the relaxation at fractional filling $\nu=2/3$ is characterized by phonon emission around a single energy, the magneto-roton gap. This leads to a strongly reduced energy relaxation rate compared to $\nu=1/2$ with only a weak temperature dependence for temperatures 150 mK $< T <$ 400 mK.Comment: 4 pages, 3 figures; 14th International Conference on High Magnetic Fields in Semiconductor Physics, September 24-29, 2000, Matsue, Japa

Does Protest Matter? The Impact of Rights-Related Protest on the Legislative Agenda

I will address two research questions: (1) Do rights-related protest events affect the congressional agenda? (2) Does political party condition the relationship between rights-related protest events and the congressional agenda? To examine these questions, I will use a crosscutting approach by distinguishing between two forms of protest – institutional and extra-institutional forms – to see if disruptive tactics had a greater impact on agenda-setting in the context of rights-related issues from 1960 until 1995. I found that extra-institutional protests related to LGBT rights as well as rights to free speech and religion had a significant impact on related congressional hearings. In addition, institutional protest was highly significant in the case of free speech and religion. However, the empirical findings provide little support for the hypothesis that hearings on rights-related issues will increase when Democrats are in control of Congress and the Presidency

Improved cultural algorithms for job shop scheduling problem

This paper presents a new cultural algorithm for job shop scheduling problem. Unlike the canonical genetic algorithm, in which random elitist selection and mutational genetics is assumed. The proposed cultural algorithm extract the useful knowledge from the population space of genetic algorithm to form belief space, and utilize it to guide the genetic operator of selection and mutation. The different sizes of the benchmark data taken from literature are used to analyze the efficacy of this algorithm. Experimental results indicate that it outperforms current approaches using canonical genetic algorithms in computational time and quality of the solutions

Visual Firewall Log Analysis -- At the Border Between Analytical and Appealing

In this paper, we present our design study on developing an interactive visual firewall log analysis system in collaboration with an IT service provider. We describe the human-centered design process, in which we additionally considered hedonic qualities by including the usage of personas, psychological need cards and interaction vocabulary. For the problem characterization we especially focus on the demands of the two main clusters of requirements: high-level overview and low-level analysis, represented by the two defined personas, namely information security officer and network analyst. This resulted in the prototype of a visual analysis system consisting of two interlinked parts. One part addresses the needs for rather strategical tasks while also fulfilling the need for an appealing appearance and interaction. The other part rather addresses the requirements for operational tasks and aims to provide a high level of flexibility. We describe our design journey, the derived domain tasks and task abstractions as well as our visual design decisions, and present our final prototypes based on a usage scenario. We also report on our capstone event, where we conducted an observed experiment and collected feedback from the information security officer. Finally, as a reflection, we propose the extension of a widely used design study process with a track for an additional focus on hedonic qualities

Data Mining In Oil Price Time Series Analysis

This paper sums up the applications of statistic models such as ARCH-family models, cointegration theory and Granger causality etc in oil price time series analysis and introduces the method of data mining combined with statistic knowledge to analysis oil price time series. In addition, the paper also explains advantages, functions, relevant technologies of this method and its potential applications in hedging the oil shock risk

A Method for Filling up the Missed Data in Information Table

Almost algorithms based on the rough sets, such as mean value method, maximum frequency method, mode method are week in supporting the hidden rules in the information tablel. By the breaking point sets in the information system, a new method for packing the missed attribute value is provided in the paper,. The method is more efficient for indicating the decision rules

Low-field diffusion magneto-thermopower of a high mobility two-dimensional electron gas

The low magnetic field diffusion thermopower of a high mobility GaAs-heterostructure has been measured directly on an electrostatically defined micron-scale Hall-bar structure at low temperature (T = 1.6 K) in the low magnetic field regime (B < 1.2 T) where delocalized quantum Hall states do not influence the measurements. The sample design allowed the determination of the field dependence of the thermopower both parallel and perpendicular to the temperature gradient, denoted respectively by Sxx (longitudinal thermopower) and Syx (Nernst-Ettinghausen coefficient). The experimental data show clear oscillations in Sxx and Syx due to the formation of Landau levels for 0.3 T < B < 1.2 T and reveal that Syx is approximately 120 times larger than Sxx at a magnetic field of 1 T, which agrees well with the theoretical prediction.Comment: 4 pages, 4 figure