Miracle-dz/UniFAR-FTUs huggingface dataset:
Learning GMM Using Elliptically Contoured Distributions

Model order selection and parameter estimation for Gaussian mixture model (GMM) are important issues for clustering analysis and density estimation. Most methods for model selection usually add a penalty term in the objective function that can penalize the models and choose an optimal one from a set of candidate models. This paper presents a simple and novel approach to determine the number of components and simultaneously estimate the parameters for GMM. By introducing the degenerating model, the proposed approach overcomes the drawback of likelihood estimate that is a non-decreasing function and can not be used to select the number of components. The degenerating model is a more general form of mixture component density and it can degenerate into the component density or a crater-like density when its parameter K varies from 1 to a bigger value. The likelihood of the crater-like density evaluated for the training data approximates to zero. This characteristic of the degenerating model forms the foundation of the proposed approach. The experimental results show robust and evident performance improvement of the approach.
Optimal atomic broadcast and multicast algorithms for wide area networks

In this paper, we study the atomic broadcast and multicast problems, two fundamental abstractions for building fault-tolerant systems. As opposed to atomic broadcast, atomic multicast allows messages to be addressed to a subset of the processes in the system, each message possibly being multicast to a different subset. We require atomic multicast algorithms to be genuine, i.e., only processes addressed by the multicast message are involved in the protocol. Our study focuses on wide area networks where groups of processes, i.e., processes physically close to each other, are inter-connected through high latency communication links. In this context, we capture the cost of algorithms, denoted latency degree, as the number of inter-group message delays between the broadcasting (multicasting) of a message and its delivery. We present an atomic multicast algorithm with a latency degree of two and show that it is optimal. We then present the first fault-tolerant atomic broadcast algorithm with a latency degree of one. To achieve such a low latency, the algorithm is proactive, i.e., it may take actions even though no messages are broadcast. Nevertheless, it is quiescent: provided that the number of broadcast messages is finite, the algorithm eventually ceases its operation. As a consequence, in runs where the algorithm becomes quiescent too early, its latency degree is two. We show that this is unavoidable, and establish a lower bound on the quiescence of atomic broadcast algorithms. These two lower bound results stem from a common cause, namely the reactiveness of the processes at the time when the message is cast (broadcast or multicast). This reveals an interesting link between the quiescence of total order algorithms and the genuineness of atomic multicast, two problems which seemed to be unrelated at first sight.
Risperidone: Treatment Response in Adult and Geriatric Patients

Objective: to Compare the Efficacy and Side Effects of Risperidone in Younger Adult and Geriatric Patients. Methods: Open Retrospective Study of 102 Consecutive Intakes, prescribed risperidone, by a mental health team. All patients were non-hospitalized community residents. Prior to initiation of risperidone, and at termination of study period, Clinical Global Impression (CGI) scores were used to track progress. Variables monitored were: concurrent use of other antipsychotics, compliance, side effects, and maintenance dosage. Results: The most common DSM-IV diagnoses were schizophrenia in the younger adult group and late onset delusional disorders in the geriatric group. Compliance was good for both groups. The geriatric group demonstrated a greater treatment response which was reached at a significantly lower dosage. There was no statistically significant difference in the occurrence of side effects. Examination of response by diagnostic category indicated that geriatric patients with late onset delusional disorder showed the best response while adults with either schizophrenia or affective syndromes also showed positive response. Conclusions: Risperidone, at lower than recommended doses, shows promise in the treatment of late onset delusional disorders and behavior syndromes of dementia. The side effect profile was benign, as was suggested by experience in treating schizophrenia. Scientifically more rigorous prospective studies for the indications and efficacy of risperidone in late onset psychotic disorders and psychoses and behavior syndromes associated with dementing illness are overdue.
Computer-Aided Evaluation of Screening Mammograms Based on Local Texture Models

We propose a new approach to diagnostic evaluation of screening mammograms based on local statistical texture models. The local evaluation tool has the form of a multivariate probability density of gray levels in a suitably chosen search window. First, the density function in the form of Gaussian mixture is estimated from data obtained by scanning of the mammogram with the search window. Then we evaluate the estimated mixture at each position and display the corresponding log-likelihood value as a gray level at the window center. The resulting log-likelihood image closely correlates with the structural details of the original mammogram and emphasizes unusual places. We assume that, in parallel use, the log-likelihood image may provide additional information to facilitate the identification of malignant lesions as untypical locations of high novelty.
ACL 2 VHDL Translator : A Simple Approach to Fill the Semantic Gap

We wrote an ACL2 to VHDL translator for our verification purpose. One major problem of translation between programming languages and the ACL2 language is the semantic gap caused by the translation; it is not easy to translate one language to another while precisely preserving its semantics. Our approach is to write a translator for a small subset of the ACL2 language for which there is no loss of semantic correctness. This seemingly restricted translator turned out to be a promising approach for combining ACL2 and VHDL testing/verification tools. This paper discusses the details of the translator and the bit-vector libraries used in the translatable ACL2 functions.
How to learn an unknown environment. I: the rectilinear case

We consider the problem faced by a robot that must explore and learn an unknown room with obstacles in it. We seek algorithms that achieve a bounded ratio of the worst-case distance traversed in order to see all visible points of the environment (thus creating a map), divided by the optimum distance needed to verify the map, if we had it in the beginning. The situation is complicated by the fact that the latter off-line problem (the problem of optimally verifying a map) is NP-hard. Although we show that there is no such “competitive” algorithm for general obstacle courses, we give a competitive algorithm for the case of a polygonal room with a bounded number of obstacles in it. We restrict ourselves to the rectilinear case, where each side of the obstacles and the room is parallel to one of the coordinates, and the robot must also move either parallel or perpendicular to the sides. (In a subsequent paper, we will discuss the extension to polygons of general shapes.) We also discuss the off-line problem for simple rectilinear polygons and find an optimal solution (in the L1 metric) in polynomial time, in the case where the entry and the exit are different points.
An experimental investigation of spin-up from rest of a stratified fluid

We examine the spin-up from rest of a stratified fluid with initial Brunt–Väisälä frequency N bound within a cylindrical container of height 2H and radius R which is set to rotate impulsively with angular speed f/2. Particular attention is given to characterizing the dependence of the form of the resulting flow on the governing parameters. Our experimental study reveals a wealth of flow behaviours and instabilities. In all experiments, the initial phase of motion is marked by the establishment of mixed axisymmetric corner regions fed by radial Ekman transport, a process detailed in Flór et al. (Flór, J.B., Ungarish, M. and Bush, J.W.M., “Spin-up from rest of a stratified fluid: boundary flows”, J. Fluid Mech., 472, 51–82 (2002). ). The subsequent evolution of the central vortex depends critically on the Burger number , where is the buoyancy frequency of the central core following the establishment of the corner regions. For B > 1.0, the axisymmetry of the system is retained throughout the spin-up process: the central vortex attains a state of near solid body rotation by the diffusion of vorticity from the sidewalls. For B < 1.0, the central core becomes baroclinically unstable, and its streamlines strained from circles into ellipses. Subsequently, for Nc/f < 1 (and B < 1.0), the symmetry of the central core is broken in a manner reminiscent of the elliptical instability. For short tanks (2H/R < 1), the instability is marked by a simple tip-over of the central core in the laboratory frame that is resisted by the core stratification. For 2H/R > 1, the centreline of the stratified core is deflected into a helical form before the core breaks into a series of stacked vortices. A Burger number criterion, , for the baroclinic instability of the central core is derived and found to be consistent with the experimental observations.
How are Java software developers using the Elipse IDE?

The Eclipse integrated development environment continues to gain popularity among Java developers. Our usage monitoring approach allows tool builders to sample how developers are using their tools in the wild. The data gathered about tool use can be used to prevent feature bloat and to evolve the environments according to user needs. Information about how developers work in a development environment can also provide a baseline for assessing new software development tools. We hope this report provides a start in defining which in formation to collect and distribute on an on going basis to help improve Eclipse and other similar platforms and tools
Flicker noise upconversion mechanisms in K-band CMOS VCOs

This paper analyzes the flicker noise upconversion mechanisms in CMOS LC-VCOs, focusing on the bias circuitry and core cross-coupled pair. In contrary to what is widely understood, a current-biased VCO does not necessarily have more upconverted flicker noise compared to a resistor-biased VCO. Resistor biasing obviously does not generate 1/f noise itself, but it allows for a transfer of the core transistors flicker noise to phase noise through AM-PM conversion and the Groszkowski effect. The high impedance of a tail current source improves the phase noise because the amplitude noise is controlled by the bias current source which can be designed with low flicker noise. On the other hand, flicker noise from the cross-coupled pair becomes a main contributor of phase noise at low offset frequency. An analytical expression is proposed to describe such mechanism. To verify the theory, three 25GHz VCOs are taped out in a CMOS 28nm process. The measurement results show that all VCOs have averaged FoM of -187dB at 10MHz offset while the current-biased VCO has 1~2dB better phase noise/FoM at 1MHz offset due to the better amplitude noise control.
What makes the difference? Practitioner views of success and failure in two effective psychiatric rehabilitation approaches

The current study examined success in two vocational programs by interviewing practitioners in two philosophically different employment programs at a psychosocial rehabilitation agency. Practitioners' views of what constitutes success and factors facilitating success were analyzed using both qualitative and quantitative means. In general, practitioners viewed success as more than just obtaining a job, but maintaining employment over time and making life changes. Success was most often attributed to consumer motivation, and lack of success was attributed to mental health symptoms. Furthermore, practitioners from each program tended to view success in a manner consistent with their program's philosophy.
Classification of Different Therapeutic Responses of Major Depressive Disorder with Multivariate Pattern Analysis Method Based on Structural MR Scans

Background Previous studies have found numerous brain changes in patients with major depressive disorder (MDD), but no neurological biomarker has been developed to diagnose depression or to predict responses to antidepressants. In the present study, we used multivariate pattern analysis (MVPA) to classify MDD patients with different therapeutic responses and healthy controls and to explore the diagnostic and prognostic value of structural neuroimaging data of MDD. Methodology/Principal Findings Eighteen patients with treatment-resistant depression (TRD), 17 patients with treatment-sensitive depression (TSD) and 17 matched healthy controls were scanned using structural MRI. Voxel-based morphometry, together with a modified MVPA technique which combined searchlight algorithm and principal component analysis (PCA), was used to classify the subjects with TRD, those with TSD and healthy controls. The results revealed that both gray matter (GM) and white matter (WM) of frontal, temporal, parietal and occipital brain regions as well as cerebellum structures had a high classification power in patients with MDD. The accuracy of the GM and WM that correctly discriminated TRD patients from TSD patients was both 82.9%. Meanwhile, the accuracy of the GM that correctly discriminated TRD or TSD patients from healthy controls were 85.7% and 82.4%, respectively; and the WM that correctly discriminated TRD or TSD patients from healthy controls were 85.7% and 91.2%, respectively. Conclusions/Significance These results suggest that structural MRI with MVPA might be a useful and reliable method to study the neuroanatomical changes to differentiate patients with MDD from healthy controls and patients with TRD from those with TSD. This method might also be useful to study potential brain regions associated with treatment response in patients with MDD.
Innateness, AlphaZero, and Artificial Intelligence

The concept of innateness is rarely discussed in the context of artificial intelligence. When it is discussed, or hinted at, it is often the context of trying to reduce the amount of innate machinery in a given system. In this paper, I consider as a test case a recent series of papers by Silver et al (Silver et al., 2017a) on AlphaGo and its successors that have been presented as an argument that a "even in the most challenging of domains: it is possible to train to superhuman level, without human examples or guidance", "starting tabula rasa. " I argue that these claims are overstated, for multiple reasons. I close by arguing that artificial intelligence needs greater attention to innateness, and I point to some proposals about what that innateness might look like.
Agent-based honeynet framework for protecting servers in campus networks

Intrusion detection systems (IDSs) and intrusion prevention systems (IPSs) that use signatures cannot protect servers from new types of internet worms. Therefore it is important to collect information about new attacks because the detection rules employed by IDSs and IPSs are formulated using this information. Honeypots are valuable security resources that act as baits for attackers. They can monitor intrusions by being probed, attacked or compromised and can detect zero-day attacks and provide researchers intending to improve security with information about the attacks. However, it is almost impossible to immediately generate detection rules from the information collected by honeypots. This study presents an agent-based honeynet framework for protecting servers in a campus network. In this framework, agents remove malicious processes and executable files on servers infected by zero-day attacks as soon as the honeynet detects them. The proposed framework provides a novel defense mechanism that protects servers from new types of internet worms effectively, without the use of signatures.
Escaping Heuristic Hollows in Real-Time Search without Learning

Real-time search is a standard approach to solving search problems in which agents have limited sensing capabilities and must act quickly. It is well known that real-time search algorithms like LRTA* and RTA* perform poorly in regions of the search space in which the heuristic function is very imprecise. Approaches that use look ahead or learning are used to overcome this drawback. They perform more computation in the planning phase compared to LRTA* andRTA* . In this paper we propose Path Real-Time A* (PRTA* ), an algorithm that, like LRTA*, performs little computation in the planning phase, but that, unlike LRTA*, terminates even if the problem does not have a solution. We show that our algorithm outperforms LRTA* and RTA* in standard real-time benchmark problems. Furthermore, we show that in some cases, PRTA* may also outperform lookahead-orlearning-enabled algorithms but carrying out significantly less computation.
The use of phrases from query texts in information retrieval (poster session)

1. In t roduct ion In this paper we examine the utility of phrases as search terms in information retrieval OR). We focus on linguistically motivated phrases as extracted from query texts by natural language processing. We use shallow syntactic processing instead of statistical processing to automatically identify candidate phrasal terms from query texts, on the assumption that syntactic phrases are expected to he more meaningful than statistically obtained word pairs, and thus more powerful for discriminating among documents. While StrT-qlkowski et el. [6] and Mitra et el . [4] have found phrases to be useful indexing units, we only use phrases for query construction, to avoid the computationally expensive process of identifying phrases for every document in a collection~ Phrases are represented using a proximity operator and issued to our IR system. To yield a "value-added" phrase representation, we investigated the effects of proximity variations on the retrieval effectiveness. We also tried to find a scheme to adjust phrasal term weights because finding an adequate term weighting scheme is critical in term-based statistical information retrieval By experimenting with weighting variations imposed on phra~! terms extracted from TREC-7 topics, we adopted a scheme to maximize the retrieval performance in our IR system. The rest of the paper is organized as follows. Section 2 presents our query constructing techniques, especially those which deal with phrasal terms. Section 3 descrihes the results of performance evaluation using TREC-8 topics. Section 4 concludes the paper.
Area- and Power-Efficient Monolithic Buck Converters With Pseudo-Type III Compensation

Monolithic PWM voltage-mode buck converters with a novel Pseudo-Type III (PT3) compensation are presented. The proposed compensation maintains the fast load transient response of the conventional Type III compensator; while the Type III compensator response is synthesized by adding a high-gain low-frequency path (via error amplifier) with a moderate-gain high-frequency path (via bandpass filter) at the inputs of PWM comparator. As such, smaller passive components and low-power active circuits can be used to generate two zeros required in a Type III compensator. Constant Gm/C biasing technique can also be adopted by PT3 to reduce the process variation of passive components, which is not possible in a conventional Type III design. Two prototype chips are fabricated in a 0.35-μm CMOS process with constant Gm/C biasing technique being applied to one of the designs. Measurement result shows that converter output is settled within 7 μs for a load current step of 500 mA. Peak efficiency of 97% is obtained at 360 mW output power, and high efficiency of 86% is measured for output power as low as 60 mW. The area and power consumption of proposed compensator is reduced by > 75 % in both designs, compared to an equivalent conventional Type III compensator.
Scoring hidden Markov models

MOTIVATION Statistical sequence comparison techniques, such as hidden Markov models and generalized profiles, calculate the probability that a sequence was generated by a given model. Log-odds scoring is a means of evaluating this probability by comparing it to a null hypothesis, usually a simpler statistical model intended to represent the universe of sequences as a whole, rather than the group of interest. Such scoring leads to two immediate questions: what should the null model be, and what threshold of log-odds score should be deemed a match to the model. RESULTS This paper analyses these two issues experimentally. Within the context of the Sequence Alignment and Modeling software suite (SAM), we consider a variety of null models and suitable thresholds. Additionally, we consider HMMer's log-odds scoring and SAM's original Z-scoring method. Among the null model choices, a simple looping null model that emits characters according to the geometric mean of the character probabilities in the columns modeled by the hidden Markov model (HMM) performs well or best across all four discrimination experiments.
The mouse visually evoked potential : neural correlates and functional applications

All human beings by nature desire to know. A sign of this is our liking for the senses; for even apart from their usefulness we like them for themselves – especially the sense of sight, since we choose seeing above practically all the others, not only as an aid to action, but also when we have no intention of acting. The reason is that sight, more than any of the other senses, gives us knowledge of things and clarifies many differences among them.
Connectivity percolation in suspensions of attractive square-well spherocylinders.

We have studied the connectivity percolation transition in suspensions of attractive square-well spherocylinders by means of Monte Carlo simulation and connectedness percolation theory. In the 1980s the percolation threshold of slender fibers has been predicted to scale as the fibers' inverse aspect ratio [Phys. Rev. B 30, 3933 (1984)PRBMDO1098-012110.1103/PhysRevB.30. 3933]. The main finding of our study is that the attractive spherocylinder system reaches this inverse scaling regime at much lower aspect ratios than found in suspensions of hard spherocylinders. We explain this difference by showing that third virial corrections of the pair connectedness functions, which are responsible for the deviation from the scaling regime, are less important for attractive potentials than for hard particles.