scholarly journals Symbolic Top-k Planning

2020 ◽  
Vol 34 (06) ◽  
pp. 9967-9974
Author(s):  
David Speck ◽  
Robert Mattmüller ◽  
Bernhard Nebel
Keyword(s):  
Empirical Analysis ◽  
Decision Problem ◽  
State Of The Art ◽  
Np Hard ◽  
Current State ◽  
Novel Approach ◽  
Planning Task ◽  
Ordinary Case

The objective of top-k planning is to determine a set of k different plans with lowest cost for a given planning task. In practice, such a set of best plans can be preferred to a single best plan generated by ordinary optimal planners, as it allows the user to choose between different alternatives and thus take into account preferences that may be difficult to model. In this paper we show that, in general, the decision problem version of top-k planning is PSPACE-complete, as is the decision problem version of ordinary classical planning. This does not hold for polynomially bounded plans for which the decision problem turns out to be PP-hard, while the ordinary case is NP-hard. We present a novel approach to top-k planning, called sym-k, which is based on symbolic search, and prove that sym-k is sound and complete. Our empirical analysis shows that sym-k exceeds the current state of the art for both small and large k.

scholarly journals Knocking on IPs: Identifying HTTPS Websites for Zero-Rated Traffic

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Mariano Di Martino ◽  
Peter Quax ◽  
Wim Lamotte
Keyword(s):  
Experimental Analysis ◽  
Service Providers ◽  
State Of The Art ◽  
Domain Name ◽  
Internet Service ◽  
Ip Address ◽  
Identification Methods ◽  
Current State ◽  
Novel Approach ◽  
Current Zero

Zero-rating is a technique where internet service providers (ISPs) allow consumers to utilize a specific website without charging their internet data plan. Implementing zero-rating requires an accurate website identification method that is also efficient and reliable to be applied on live network traffic. In this paper, we examine existing website identification methods with the objective of applying zero-rating. Furthermore, we demonstrate the ineffectiveness of these methods against modern encryption protocols such as Encrypted SNI and DNS over HTTPS and therefore show that ISPs are not able to maintain the current zero-rating approaches in the forthcoming future. To address this concern, we present “Open-Knock,” a novel approach that is capable of accurately identifying a zero-rated website, thwarts free-riding attacks, and is sustainable on the increasingly encrypted web. In addition, our approach does not require plaintext protocols or preprocessed fingerprints upfront. Finally, our experimental analysis unveils that we are able to convert each IP address to the correct domain name for each website in the Tranco top 6000 websites list with an accuracy of 50.5% and therefore outperform the current state-of-the-art approaches.

ON THE HARDNESS OF THE BORDER LENGTH MINIMIZATION PROBLEM ON A RECTANGULAR ARRAY

2010 ◽  
Vol 21 (06) ◽  
pp. 1089-1100 ◽  
Author(s):  
VAMSI KUNDETI ◽  
SANGUTHEVAR RAJASEKARAN
Keyword(s):  
Gene Expression ◽  
Expression Profiling ◽  
State Of The Art ◽  
Combinatorial Problem ◽  
Np Hard ◽  
Microarray Technology ◽  
Rectangular Grid ◽  
Rectangular Array ◽  
Current State ◽  
Invaluable Tool

DNA microarray technology has proven to be an invaluable tool for molecular biologists. Microarrays are used extensively in SNP detection, genomic hybridization, alternative splicing and gene expression profiling. However the manufacturers of the microarrays are often stuck with the problem of minimizing the effects of unwanted illumination (border length minimization (BLM)) which is a hard combinatorial problem. In this paper we prove that the BLM problem on a rectangular grid is NP-hard – this however does not mean the BLM problem on a square grid is NP-hard. We also give the first integer linear programming (ILP) formulation to solve BLM problem optimally. Experimental results indicate that our ILP method produces superior results (both in runtime and cost) compared to the current state of the art algorithms to solve the BLM problem optimally.

Robust Feature Points Extraction Based on Harris and SIFT

2013 ◽  
Vol 347-350 ◽  
pp. 3500-3504
Author(s):  
Xiao Ran Guo ◽  
Shao Hui Cui ◽  
Fang Dan
Keyword(s):  
Video Sequence ◽  
State Of The Art ◽  
Image Motion ◽  
Video Sequences ◽  
Stabilization System ◽  
Feature Points ◽  
Image Stabilization ◽  
Current State ◽  
Novel Approach ◽  
Key Points

This article presents a novel approach to extract robust local feature points of video sequence in digital image stabilization system. Robust Harris-SIFT detector is proposed to select the most stable SIFT key points in the video sequence where image motion is happened due to vehicle or platform vibration. Experimental results show that the proposed scheme is robust to various transformations of video sequences, such as translation, rotation and scaling, as well as blurring. Compared with the current state-of-the-art schemes, the proposed scheme yields better performances.

scholarly journals LEO: Liquid Exploration Online

2020 ◽  
Vol 2 (1) ◽  
pp. 58-80
Author(s):  
Frank Hoeller
Keyword(s):  
Path Planning ◽  
State Of The Art ◽  
Simulation Experiments ◽  
Coverage Path Planning ◽  
Current State ◽  
Extensive Evaluation ◽  
Novel Approach ◽  
Local Navigation ◽  
Local Decision ◽  
Real Robot

This article introduces a novel approach to the online complete- coverage path planning (CCPP) problem that is specically tailored to the needs of skid-steer tracked robots. In contrast to most of the current state-of-the-art algorithms for this task, the proposed algorithm reduces the number of turning maneuvers, which are responsible for a large part of the robot's energy consumption. Nevertheless, the approach still keeps the total distance traveled at a competitive level. The algorithm operates on a grid-based environment representation and uses a 3x3 prioritization matrix for local navigation decisions. This matrix prioritizes cardinal di- rections leading to a preference for straight motions. In case no progress can be achieved based on a local decision, global path planning is used to choose a path to the closest known unvisited cell, thereby guaranteeing completeness of the approach. In an extensive evaluation using simulation experiments, we show that the new algorithm indeed generates competi- tively short paths with largely reduced turning costs, compared to other state-of-the-art CCPP algorithms. We also illustrate its performance on a real robot.

scholarly journals A System for Extracting Study Design Parameters from Nutritional Genomics Abstracts

2013 ◽  
Vol 10 (2) ◽  
pp. 82-93 ◽  
Author(s):  
Cassidy Kelly ◽  
Hui Yang
Keyword(s):  
Language Processing ◽  
Study Design ◽  
State Of The Art ◽  
Design Parameters ◽  
Regular Expressions ◽  
Journal Articles ◽  
Current State ◽  
Novel Approach ◽  
Algorithmic Framework ◽  
Nutritional Genomics

Summary The extraction of study design parameters from biomedical journal articles is an important problem in natural language processing (NLP). Such parameters define the characteristics of a study, such as the duration, the number of subjects, and their profile. Here we present a system for extracting study design parameters from sentences in article abstracts. This system will be used as a component of a larger system for creating nutrigenomics networks from articles in the nutritional genomics domain. The algorithms presented consist of manually designed rules expressed either as regular expressions or in terms of sentence parse structure. A number of filters and NLP tools are also utilized within a pipelined algorithmic framework. Using this novel approach, our system performs extraction at a finer level of granularity than comparable systems, while generating results that surpass the current state of the art.

Mining Largest Maximal Quasi-Cliques

2021 ◽  
Vol 15 (5) ◽  
pp. 1-21
Author(s):  
Seyed-Vahid Sanei-Mehri ◽  
Apurba Das ◽  
Hooman Hashemi ◽  
Srikanta Tirthapura
Keyword(s):  
Social Network ◽  
Social Network Analysis ◽  
Network Analysis ◽  
Heuristic Algorithm ◽  
State Of The Art ◽  
Experimental Results ◽  
Np Hard ◽  
Challenging Problem ◽  
Current State ◽  
Clique Enumeration

Quasi-cliques are dense incomplete subgraphs of a graph that generalize the notion of cliques. Enumerating quasi-cliques from a graph is a robust way to detect densely connected structures with applications in bioinformatics and social network analysis. However, enumerating quasi-cliques in a graph is a challenging problem, even harder than the problem of enumerating cliques. We consider the enumeration of top- k degree-based quasi-cliques and make the following contributions: (1) we show that even the problem of detecting whether a given quasi-clique is maximal (i.e., not contained within another quasi-clique) is NP-hard. (2) We present a novel heuristic algorithm K ernel QC to enumerate the k largest quasi-cliques in a graph. Our method is based on identifying kernels of extremely dense subgraphs within a graph, followed by growing subgraphs around these kernels, to arrive at quasi-cliques with the required densities. (3) Experimental results show that our algorithm accurately enumerates quasi-cliques from a graph, is much faster than current state-of-the-art methods for quasi-clique enumeration (often more than three orders of magnitude faster), and can scale to larger graphs than current methods.

Interactions Between Ketamine and Magnesium for the Treatment of Pain: Current State of the Art

2021 ◽  
Vol 20 ◽  
Author(s):  
Katarina Savić Vujović ◽  
Sonja Vučković ◽  
Radan Stojanović ◽  
Nevena Divac ◽  
Branislava Medić ◽  
...  
Keyword(s):  
State Of The Art ◽  
New Drugs ◽  
Nmda Receptor Antagonists ◽  
Dosing Regimen ◽  
Chronological Order ◽  
The Past ◽  
Current State ◽  
Novel Approach ◽  
Dosage Administration ◽  
Novel Therapeutic

Background: Over the past three decades, NMDA-receptor antagonists have been shown to be efficient drugs for treating pain and particularly pain that is resistant to conventional analgesics. Emphasis will be on the old-new drugs, ketamine and magnesium and their combination as a novel approach for treating chronic pain. Methods: The MEDLINE database was searched via PubMed for articles which were published up to March 1, 2020 with the key words ‘ketamine’, ‘magnesium’ and ‘pain’ (in the title/abstract). Results: Studies in animals, as well as humans have shown that interactions of ketamine and magnesium can be additive, antagonistic and synergistic. These discrepancies might be due to differences in magnesium and ketamine dosage, administration times and the chronological order of drugs administration. Different kinds of pain can also be the source of divergent results. Conclusion: This review explains why studies performed with a combination of ketamine and magnesium have given inconsistent results. Because of the lack of efficacy of drugs available for pain, ketamine and magnesium in combination provide a novel therapeutic approach that needs to be standardized with a suitable dosing regimen, including the chronological order of drug administration.

Behavioral Genetics: Concepts for Research and Practice in Language Development and Disorders

1995 ◽  
Vol 38 (5) ◽  
pp. 1126-1142 ◽  
Author(s):  
Jeffrey W. Gilger
Keyword(s):  
Language Development ◽  
Behavioral Genetics ◽  
State Of The Art ◽  
Genetic Research ◽  
Great Promise ◽  
Behavioral Genetic ◽  
Fine Grained ◽  
Future Goals ◽  
Current State ◽  
Research Designs

This paper is an introduction to behavioral genetics for researchers and practioners in language development and disorders. The specific aims are to illustrate some essential concepts and to show how behavioral genetic research can be applied to the language sciences. Past genetic research on language-related traits has tended to focus on simple etiology (i.e., the heritability or familiality of language skills). The current state of the art, however, suggests that great promise lies in addressing more complex questions through behavioral genetic paradigms. In terms of future goals it is suggested that: (a) more behavioral genetic work of all types should be done—including replications and expansions of preliminary studies already in print; (b) work should focus on fine-grained, theory-based phenotypes with research designs that can address complex questions in language development; and (c) work in this area should utilize a variety of samples and methods (e.g., twin and family samples, heritability and segregation analyses, linkage and association tests, etc.).

Schizophrenia Research: Current State of the Art

1976 ◽  
Vol 21 (7) ◽  
pp. 497-498
Author(s):  
STANLEY GRAND
Keyword(s):  
State Of The Art ◽  
Current State

Umbral Calculus

10.37236/24 ◽  
2002 ◽  
Vol 1000 ◽  
Author(s):  
A. Di Bucchianico ◽  
D. Loeb
Keyword(s):  
19Th Century ◽  
Finite Differences ◽  
State Of The Art ◽  
Umbral Calculus ◽  
Current State ◽  
Logical Foundation ◽  
Complete Bibliography ◽  
The 19Th Century ◽  
Mathematical Literature

We survey the mathematical literature on umbral calculus (otherwise known as the calculus of finite differences) from its roots in the 19th century (and earlier) as a set of “magic rules” for lowering and raising indices, through its rebirth in the 1970’s as Rota’s school set it on a firm logical foundation using operator methods, to the current state of the art with numerous generalizations and applications. The survey itself is complemented by a fairly complete bibliography (over 500 references) which we expect to update regularly.

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