5,907 research outputs found
Measuring and analyzing German and Spanish customer satisfaction of using the iPhone 4S Mobile Cloud service
No full textThis paper presents the customer satisfaction analysis for measuring popularity in the Mobile Cloud, which is an emerging area in the Cloud and Big Data Computing. Organizational Sustainability Modeling (OSM) is the proposed method used in this research. The twelve-month of German and Spanish consumer data are used for the analysis to investigate the return and risk status associated with the ratings of customer satisfaction in the iPhone 4S Mobile Cloud services. Results show that there is a decline in the satisfaction ratings in Germany and Spain due to economic downturn and competitions in the market, which support our hypothesis. Key outputs have been explained and they confirm that all analysis and interpretations fulfill the criteria for OSM. The use of statistical and visualization method proposed by OSM can expose unexploited data and allows the stakeholders to understand the status of return and risk of their Cloud strategies easier than the use of other data analysis
Why are CSPs Based on Partition Schemes Computationally Hard?
No full textMany computational problems arising in, for instance, artificial intelligence can be realized as infinite-domain constraint satisfaction problems (CSPs) based on partition schemes: a set of pairwise disjoint binary relations (containing the equality relation) whose union spans the underlying domain and which is closed under converse. We first consider partition schemes that contain a strict partial order and where the constraint language contains all unions of the basic relations; such CSPs are frequently occurring in e.g. temporal and spatial reasoning. We identify three properties of such orders which, when combined, are sufficient to establish NP-hardness of the CSP. This result explains, in a uniform way, many existing hardness results from the literature. More importantly, this result enables us to prove that CSPs of this kind are not solvable in subexponential time unless the exponential-time hypothesis (ETH) fails. We continue by studying constraint languages based on partition schemes but where relations are built using disjunctions instead of unions; such CSPs appear naturally when analysing first-order definable constraint languages. We prove that such CSPs are NP-hard even in very restricted settings and that they are not solvable in subexponential time under the randomised ETH. In certain cases, we can additionally show that they cannot be solved in O(c^n) time for any c >= 0
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A Norwegian grey zone: Knut Rød, Victor Lind and 'The crucial year, 1942'
No full textThis article uses Primo Levi’s concept of “the grey zone” to explore Knut Rød’s involvement in the transfer of 532 Norwegian Jews from Oslo to Auschwitz in 1942. Rød, the police chief in charge of the operation, was subsequently exonerated of any crime on the grounds that he had simultaneously used his position to help members of Milorg – the Norwegian Resistance. The legal and moral basis of this verdict has been questioned by the artist Victor Lind in a series of artworks, including his “countermonument” The Perpetrator (2005)
Reasoning Short Cuts in Infinite Domain Constraint Satisfaction: Algorithms and Lower Bounds for Backdoors
No full textA backdoor in a finite-domain CSP instance is a set of variables where each possible instantiation moves the instance into a polynomial-time solvable class. Backdoors have found many applications in artificial intelligence and elsewhere, and the algorithmic problem of finding such backdoors has consequently been intensively studied. Sioutis and Janhunen (KI, 2019) have proposed a generalised backdoor concept suitable for infinite-domain CSP instances over binary constraints. We generalise their concept into a large class of CSPs that allow for higher-arity constraints. We show that this kind of infinite-domain backdoors have many of the positive computational properties that finite-domain backdoors have: the associated computational problems are fixed-parameter tractable whenever the underlying constraint language is finite. On the other hand, we show that infinite languages make the problems considerably harder
Victor LaValle
No full textVictor LaValle is the author of the short story collection Slapboxing with Jesus, four novels, The Ecstatic, Big Machine, The Devil in Silver, and The Changeling and two novellas, Lucretia and the Kroons and The Ballad of Black Tom. He is also the creator and writer of a comic book Victor LaValle’s DESTROYER. He has been the recipient of numerous awards including a Whiting Writers’ Award, a United States Artists Ford Fellowship, a Guggenheim Fellowship, a Shirley Jackson Award, an American Book Award, and the key to Southeast Queens. He was raised in Queens, New York. He now lives in Washington Heights with his wife and kids. He teaches at Columbia University. The free, public program begins at 6:00 p.m. at Burns Belfry.https://egrove.olemiss.edu/grisham_vis/1002/thumbnail.jp
Time Complexity of Constraint Satisfaction via Universal Algebra
No full textThe exponential-time hypothesis (ETH) states that 3-SAT is not solvable in subexponential time, i.e. not solvable in O(c^n) time for arbitrary c > 1, where n denotes the number of variables. Problems like k-SAT can be viewed as special cases of the constraint satisfaction problem (CSP), which is the problem of determining whether a set of constraints is satisfiable. In this paper we study the worst-case time complexity of NP-complete CSPs. Our main interest is in the CSP problem parameterized by a constraint language Gamma (CSP(Gamma)), and how the choice of Gamma affects the time complexity. It is believed that CSP(Gamma) is either tractable or NP-complete, and the algebraic CSP dichotomy conjecture gives a sharp delineation of these two classes based on algebraic properties of constraint languages. Under this conjecture and the ETH, we first rule out the existence of subexponential algorithms for finite domain NP-complete CSP(Gamma) problems. This result also extends to certain infinite-domain CSPs and structurally restricted CSP(Gamma) problems. We then begin a study of the complexity of NP-complete CSPs where one is allowed to arbitrarily restrict the values of individual variables, which is a very well-studied subclass of CSPs. For such CSPs with finite domain D, we identify a relation SD such that (1) CSP({SD}) is NP-complete and (2) if CSP(Gamma) over D is NP-complete and solvable in O(c^n) time, then CSP({SD}) is solvable in O(c^n) time, too. Hence, the time complexity of CSP({SD}) is a lower bound for all CSPs of this particular kind. We also prove that the complexity of CSP({SD}) is decreasing when |D| increases, unless the ETH is false. This implies, for instance, that for every c>1 there exists a finite-domain Gamma such that CSP(Gamma) is NP complete and solvable in O(c^n) time
CSPs with Few Alien Constraints
No full textThe constraint satisfaction problem asks to decide if a set of constraints over a relational structure is satisfiable (CSP()). We consider CSP( ∪ ℬ) where is a structure and ℬ is an alien structure, and analyse its (parameterized) complexity when at most k alien constraints are allowed. We establish connections and obtain transferable complexity results to several well-studied problems that previously escaped classification attempts. Our novel approach, utilizing logical and algebraic methods, yields an FPT versus pNP dichotomy for arbitrary finite structures and sharper dichotomies for Boolean structures and first-order reducts of (ℕ, =) (equality CSPs), together with many partial results for general ω-categorical structures
[Diary Entry for Saturday, April 13, 1940]
No full textThis page is part of a diary by Sir Ellice Victor Elias Sassoon. He wrote that he slept a lot and read a book about the Burma Road for which the author got the idea at his garden party in 1937. He then said he went to bed at 8 and that Edna came in to ask how he was
OneVerse Ache NT Dedication & Celebration: Dr. Victor Gomez
No full textVictor Antonio Gomez celebrates, dedicates, and shares about OneVerse’s translation of New Testament in the language of the Ache people.
Victor Antonio Gomez, Paraguayan, is married to Cristina Flores and has two daughters: Rocio (22) and Jazmin (Taylor ’16). He has a Ph.D. in theology and served as Baptist pastor and professor of several seminaries before becoming a Bible Translator for the Ache people and Director of LETRA Paraguay. Author and editor of several books, he also serves as Wycliffe Global Alliance Bible Translation Coordinator and Sub-director for the Americas
Letter from JV [John Victor] Carson, Dominguez Estate Company to J.S. Yoshinobu, June 3, 1938
No full textLetter making final request for information no Mr. Kuda's lease information. Signed by JV [John Victor] Carson
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