A self-learning rule base for command following in dynamical systems

In this paper, a self-learning Rule Base for command following in dynamical systems is presented. The learning is accomplished though reinforcement learning using an associative memory called SAM. The main advantage of SAM is that it is a function approximator with explicit storage of training samples. A learning algorithm patterned after the dynamic programming is proposed. Two artificially created, unstable dynamical systems are used for testing, and the Rule Base was used to generate a feedback control to improve the command following ability of the otherwise uncontrolled systems. The numerical results are very encouraging. The controlled systems exhibit a more stable behavior and a better capability to follow reference commands. The rules resulting from the reinforcement learning are explicitly stored and they can be modified or augmented by human experts. Due to overlapping storage scheme of SAM, the stored rules are similar to fuzzy rules

Constructed Borders in Higher Education: A Critical Policy Analysis of Undocumented College Students\u27 Access to Study Abroad

Abstract Between 2012 and 2017, undocumented youth in the United States with Deferred Action for Childhood Arrival status were able to apply for Advance Parole permissions to travel abroad for educational purposes. During this time, DACA students attending colleges and universities across the nation engaged in study abroad through established education abroad programs. This qualitative study examines undocumented students’ decision to pursue educational abroad opportunities during their undergraduate education in the context of national, state and institutional policies and climate and compares and contrasts the experiences of the undocumented college students who successfully studied abroad with those who either attempted but did not go or never accessed the opportunity. The study uses a Critical Policy Analysis methodological approach to uncover how the decision to study abroad impacts students’ undergraduate experience and future planning. Critical Policy Analysis examines power and privilege imbalances and goes beyond the linear fashion of a Traditional Policy Analysis approach. This temporary and now halted program shows the three main findings of how 1) the policies that intersect immigration and education can both be empowering and disempowering 2) through the consideration of study abroad, undocumented students question and challenge their place in the hierarchy that exist between them and other documented students and also between them and other undocumented youth, and 3) due to the gap that exists between policy rhetoric and practices, undocumented students exist by living within the limitations of policies while at the same time, finding ways to resist against those limitations

Optimal two-stage filtering of elastograms

In ultrasound elastography, tissue axial strains are obtained through the differentiation of measured axial displacements. However, during the measurement process, the displacement signals are often contaminated with de-correlation noise caused by changes in the speckle pattern in the tissue. Thus, the application of the gradient operator on the displacement signals results in the presence of amplified noise in the axial strains, which severely obscures the useful information. The use of an effective denoising scheme is therefore imperative. In this paper, a method based on a two-stage consecutive filtering approach is proposed for the accurate estimation of axial strains. The presented method considers a cascaded system of a frequency filter and a time window, which are both designed such that the overall system operates optimally as a minimum variance estimator. Experimentation on simulated signals shows that the two-stage scheme employed in this study has good potential as a denoising method for ultrasound elastograms

Preliminary Candidate Advanced Avionics System (PCAAS)

Specifications which define the system functional requirements, the subsystem and interface needs, and other requirements such as maintainability, modularity, and reliability are summarized. A design definition of all required avionics functions and a system risk analysis are presented

Succinct Dictionary Matching With No Slowdown

The problem of dictionary matching is a classical problem in string matching: given a set S of d strings of total length n characters over an (not necessarily constant) alphabet of size sigma, build a data structure so that we can match in a any text T all occurrences of strings belonging to S. The classical solution for this problem is the Aho-Corasick automaton which finds all occ occurrences in a text T in time O(|T| + occ) using a data structure that occupies O(m log m) bits of space where m <= n + 1 is the number of states in the automaton. In this paper we show that the Aho-Corasick automaton can be represented in just m(log sigma + O(1)) + O(d log(n/d)) bits of space while still maintaining the ability to answer to queries in O(|T| + occ) time. To the best of our knowledge, the currently fastest succinct data structure for the dictionary matching problem uses space O(n log sigma) while answering queries in O(|T|log log n + occ) time. In this paper we also show how the space occupancy can be reduced to m(H0 + O(1)) + O(d log(n/d)) where H0 is the empirical entropy of the characters appearing in the trie representation of the set S, provided that sigma < m^epsilon for any constant 0 < epsilon < 1. The query time remains unchanged.Comment: Corrected typos and other minor error

Observation and Numerical Simulation of Terrain-Induced Windshear at the Hong Kong International Airport in a Planetary Boundary Layer without Temperature Inversions

Terrain-induced windshear at Hong Kong International Airport (HKIA) could be hazardous to the landing and departing aircraft. Such windshear occurring in a planetary boundary layer without temperature inversions is studied in this paper by using the data from the Terminal Doppler Weather Radar and Light Detection and Ranging systems. A high resolution numerical model, called aviation model (AVM), is also employed to find out its capability to forecast the occurrence of such windshear. The model is found to have skills in capturing the terrain-induced windshear, including the terrain-induced microburst due to the mountains of Lantau Island. Moreover, the windshear detection algorithm as applied to the AVM output, called AVM-GLYGA, is able to give advance alert for the occurrence of low-level windshear. The model also offers new dataset, such as vertical velocity and vertical cross sections across the windshear feature, to study the terrain-induced windshear phenomena with new insights. The AVM is found to have good skills in depicting the terrain-disrupted airflow at the airport area, and more comprehensive study would be conducted to study the skills of AVM-GLYGA as compared with pilot windshear report as sky truth

The Independence of the Judiciary as the Base of Business and Economic Development

The rapid nature of information exchange, the increasingly porous nature of international boundaries through electronic communications and the movement of capital and labour have presented a range of new issues in the administration of justice. These have major implications for the Courts and the role of the Courts, particularly in newly liberalised economies. International trade has raised issues concerning both substantive law and procedure. Foreign investment in the Asia Pacific region and the increasing affluence of particular socio-economic groups in countries throughout Asia and the Pacific has seen increasing demands for the reform of the law and the methods of its enforcement in order to provide consistency and coherency in commercial relationships