1,515 research outputs found
Strongly Refuting Random CSPs Below the Spectral Threshold
Random constraint satisfaction problems (CSPs) are known to exhibit threshold
phenomena: given a uniformly random instance of a CSP with variables and
clauses, there is a value of beyond which the CSP will be
unsatisfiable with high probability. Strong refutation is the problem of
certifying that no variable assignment satisfies more than a constant fraction
of clauses; this is the natural algorithmic problem in the unsatisfiable regime
(when ).
Intuitively, strong refutation should become easier as the clause density
grows, because the contradictions introduced by the random clauses become
more locally apparent. For CSPs such as -SAT and -XOR, there is a
long-standing gap between the clause density at which efficient strong
refutation algorithms are known, , and the
clause density at which instances become unsatisfiable with high probability,
.
In this paper, we give spectral and sum-of-squares algorithms for strongly
refuting random -XOR instances with clause density in time or in
rounds of the sum-of-squares hierarchy, for any
and any integer . Our algorithms provide a smooth
transition between the clause density at which polynomial-time algorithms are
known at , and brute-force refutation at the satisfiability
threshold when . We also leverage our -XOR results to obtain
strong refutation algorithms for SAT (or any other Boolean CSP) at similar
clause densities. Our algorithms match the known sum-of-squares lower bounds
due to Grigoriev and Schonebeck, up to logarithmic factors.
Additionally, we extend our techniques to give new results for certifying
upper bounds on the injective tensor norm of random tensors
Eupsychian Management: Organizational Change, Behavior, Motivation, And Trust
In Part 1 of this real-life incident, Professor Carson is teaching the customary material associated with the multiple theories of leadership, motivation, and organizational behavior. He deviates slightly from the way he normally presents these standard concepts and theories and divulges the concept of Eupsychian Management â a culture in which self-actualizing people behave in ways where trust begets trust and work is viewed as natural as play or rest. The class is given the following website www.interpolis.nl which demonstrates how the built environment of Interpolis relates to its organizational culture and behavior. In Part 2, the content of a personal interview that he conducted in Tilburg, The Netherlands â the home of Interpolis is elaborated. A new organizational culture based on âtrustâ â both of employees and customers is revealed. The end performance results and the productivity metrics are unbelievably high. The reader is challenged to address the content of seven penetrating questions and instructions which are part of the learning module; then, is asked to complete the case log and administrative journal entry
Conservation and Land Use Planning: Linking Municipal Capacity and Biodiversity Outcomes
CaRDI Research & Policy Brief Issue 7
"Grass" By Any Other Name - Xeriscaping And Sustainability
With water conservation and use policy considered to be among the greatest challenges facing contemporary society, this case takes on the enduring issues associated with water and how it impacts urban planning, land use, water conservation, economic development, and sustainability. Conflicted on the uses of natural and artificial turf, Jerard Leon, director of Blue Havens Planning Commission recommends that Joseph Teaberry, landscape architect, contact a premier program on xeriscape in the United States the Southern Nevada Water Authority (SNWA). Teaberry prepares for an in-depth, structured interview with Doug Bennett, conservation manager of SNWA. He reviews the relevant academic and professional literature on the hydrologic cycle, and the economics and geological concerns that affect water use policy, including the meaning of Water quality, Watershed, and the sundry metrics used to assess water quality under the Clean Water Act, 1972. As the structured interview reveals, Teaberry learns about the history of water policy in the Colorado Basin, the multiple uses and costs associated with water consumption in the SNWA, and the conservation practices and water policy pricing policies and how they impact water utilization. In the final analysis, Teaberry discusses the various strategic management practices employed by SNWA and their attendant efficacies, successes/failures pertaining to water policy education, pricing, inducement, enforcement, and the future water policy concerns. The case has several take-away points associated with xeriscape policy, followed by six poignant questions that stimulate broad discussion on the general areas of water resource policy
Explorations, Vol. 2, No. 3
Cover image: Ezra Pound
Dedication: With affection and respect, this issue of EXPLORATIONS is dedicated to Carroll Terrell, Professor Emeritus of English.
Articles include: Carroll Terrell and the Great American Poetry Wars, by Burton Hatlen
Adventures in China, by H.Y. Forsythe, Jr.
Harry Kern and the Making of the New Japan, by Howard B. Schonberger
From the Dispatch Case: update on malnutrition in Maine, by Richard Cook
Changing Approaches to Protein Structure Determination, by Robert Anderegg
The Search of Effective Policy: Meeting the Challenge of an Aging Society, by Dennis A. Watkins and Julia M. Watkins
Citizen Survey of the Maine State Police, by Robert A. Stron
A Broadband Study of the Emission from the Composite Supernova Remnant MSH 11-62
MSH 11-62 (G291.1-0.9) is a composite supernova remnant for which radio and
X-ray observations have identified the remnant shell as well as its central
pulsar wind nebula. The observations suggest a relatively young system
expanding into a low density region. Here we present a study of MSH 11-62 using
observations with the Chandra, XMM-Newton, and Fermi observatories, along with
radio observations from the Australia Telescope Compact Array (ATCA). We
identify a compact X-ray source that appears to be the putative pulsar that
powers the nebula, and show that the X-ray spectrum of the nebula bears the
signature of synchrotron losses as particles diffuse into the outer nebula.
Using data from the Fermi LAT, we identify gamma-ray emission originating from
MSH 11-62. With density constraints from the new X-ray measurements of the
remnant, we model the evolution of the composite system in order to constrain
the properties of the underlying pulsar and the origin of the gamma-ray
emission.Comment: 12 Pages, 12 figures. Accepted for publication in the Astrophysical
Journa
Canagliflozin retards age-related lesions in heart, kidney, liver, and adrenal gland in genetically heterogenous male mice.
Canagliflozin (Cana), a clinically important anti-diabetes drug, leads to a 14% increase in median lifespan and a 9% increase in the 90th percentile age when given to genetically heterogeneous male mice from 7 months of age, but does not increase lifespan in female mice. A histopathological study was conducted on 22-month-old mice to see if Cana retarded diverse forms of age-dependent pathology. This agent was found to diminish incidence or severity, in male mice only, of cardiomyopathy, glomerulonephropathy, arteriosclerosis, hepatic microvesicular cytoplasmic vacuolation (lipidosis), and adrenal cortical neoplasms. Protection against atrophy of the exocrine pancreas was seen in both males and females. Thus, the extension of lifespan in Cana-treated male mice, which is likely to reflect host- or tumor-mediated delay in lethal neoplasms, is accompanied by parallel retardation of lesions, in multiple tissues, that seldom if ever lead to death in these mice. Canagliflozin thus can be considered a drug that acts to slow the aging process and should be evaluated for potential protective effects against many other late-life conditions
Rapamycinâmediated lifespan increase in mice is dose and sex dependent and metabolically distinct from dietary restriction
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107367/1/acel12194.pd
Acarbose, 17âαâestradiol, and nordihydroguaiaretic acid extend mouse lifespan preferentially in males
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106661/1/acel12170.pd
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