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Confronting Intractability via Parameters [article]

Rodney G. Downey, Dimitrios M. Thilikos
2011 arXiv   pre-print
One approach to confronting computational hardness is to try to understand the contribution of various parameters to the running time of algorithms and the complexity of computational tasks.  ...  It is not hard to imagine that some parameters contribute more intractability than others and it seems reasonable to develop a theory of computational complexity which seeks to exploit this fact.  ...  If we have algorithms running in time n c , for some c that is independent of k, we regard this as being (fixed-parameter) tractable, and if c increases with k, then this problem is regarded as being intractable  ... 
arXiv:1106.3161v6 fatcat:6eqwtzfmunffzokn47lqyb6xwq

Confronting intractability via parameters

Rodney G. Downey, Dimitrios M. Thilikos
2011 Computer Science Review  
One approach to confronting computational hardness is to try to understand the contribution of various parameters to the running time of algorithms and the complexity of computational tasks.  ...  It is not hard to imagine that some parameters contribute more intractability than others and it seems reasonable to develop a theory of computational complexity which seeks to exploit this fact.  ...  If we have algorithms running in time n c , for some c that is independent of k, we regard this as being (fixed-parameter) tractable, and if c increases with k, then this problem is regarded as being intractable  ... 
doi:10.1016/j.cosrev.2011.09.002 fatcat:4efih5lobfbjdgyuu2ccbqlbbq

The factors driving self-efficacy in intractable chronic pain patients: a retrospective study

Hironori Tsuji, Tomoko Tetsunaga, Tomonori Tetsunaga, Keiichiro Nishida, Haruo Misawa, Toshifumi Ozaki
2019 Journal of Orthopaedic Surgery and Research  
On the other hand, self-efficacy influences whether patients view their pain optimistically, ultimately preventing the conversion of pain into intractable pain.  ...  Study participants included 147 outpatients (35 men, 112 women) with intractable chronic pain who visited our hospital between September 2014 and July 2015.  ...  As a protective factor against this vicious pain spiral, confrontation, which was assessed via PSEQ in this study, serves an important role.  ... 
doi:10.1186/s13018-019-1535-9 pmid:31888662 pmcid:PMC6936134 fatcat:5kaxupwgmzb2jbnip64anzmzuy

Telemedical Deep Brain Stimulation: Merits and Limitations

Chencheng Zhang, Yingying Zhang, Shikun Zhan, Dianyou Li, Haiyan Jin, Damiaan Denys, Bomin Sun
2018 Stereotactic and Functional Neurosurgery  
Lastly, we describe a 36-year-old male patient who had suffered from intractable OCD for 20 years.  ...  The patient completed all postsurgery programming via the Internet, except a threshold check session conducted in a hospital.  ...  Briefly, parameter adjustments can be delivered via a Bluetooth-enabled dedicated device or mobile smartphone, to patients in their home environment or local hospital, while the control of the DBS programming  ... 
doi:10.1159/000491603 pmid:30184552 fatcat:rqamaxhne5bxdju7lyw6nn66bm

Book Review: Deep Learning

Kwang Gi Kim
2016 Healthcare Informatics Research  
Approximate Inference This chapter introduces several of the techniques used to confront these intractable inference problems. Chapter 20.  ...  Confronting the Partition Function In this chapter, the authors describe techniques used for training and evaluating models that have intractable parti-tion functions. Chapter 19.  ... 
doi:10.4258/hir.2016.22.4.351 pmcid:PMC5116548 fatcat:oz5b4rswyfg5fgfhy4ya2u6qhy

New Method for Parameter Estimation in Probabilistic Models: Minimum Probability Flow

Jascha Sohl-Dickstein, Peter B. Battaglino, Michael R. DeWeese
2011 Physical Review Letters  
Fitting probabilistic models to data is often difficult, due to the general intractability of the partition function.  ...  We propose a new parameter fitting method, minimum probability flow (MPF), which is applicable to any parametric model.  ...  p ð1Þ i ðÞ usually involves an intractable sum over all system states.  ... 
doi:10.1103/physrevlett.107.220601 pmid:22182019 fatcat:7x6msu7zm5bidojity33e4hh5a

Page 5764 of Mathematical Reviews Vol. , Issue 2000h [page]

2000 Mathematical Reviews  
(NZ-VCTR-SMC; Wellington); Fellows, Michael R. (3-VCTR-C; Victoria, BC); Stege, Ulrike (CH-ETHZ-CBK; Ziirich) Parameterized complexity: a framework for systematically confronting computational intractability  ...  Such problems are called fixed parameter tractable.  ... 

Can f(R) gravity relieve $$H_0$$ and $$\sigma _8$$ tensions?

Deng Wang
2021 European Physical Journal C: Particles and Fields  
parameters.  ...  We find that this model fails to relieve both $$H_0$$ H 0 and $$\sigma _8$$ σ 8 tensions, and that its two typical parameters $$\log _{10}f_{R0}$$ log 10 f R 0 and n are insensitive to other cosmological  ...  To some extent, one can predict its H 0 behavior via Eq. (7).  ... 
doi:10.1140/epjc/s10052-021-09264-9 fatcat:7pkkhxaebzhpfoopnybucmarlq

Refining Intractability: A Case Study of Entrapment in the Syrian Civil War

Siniša Vuković, Diane Bernabei
2019 International Negotiation  
Existing studies on intractability have emphasized the resistance to solution as a crucial indicator of intractability, and subsequently explored the phases through which intractability evolves and key  ...  What is largely missing is a nuanced explanation of at what point resistance turns into intractability.  ...  Downloaded from Brill.com05/05/2020 11:53:50PM via free access  ... 
doi:10.1163/15718069-24031191 fatcat:ghcqwtntknhzppiu2nitkohnli

Genomic Network Tomography

Michael G. Rabbat, Mario A.T Figueiredo, Robert D. Nowak
2007 2007 IEEE International Conference on Acoustics, Speech and Signal Processing - ICASSP '07  
., starvation, heat shock) via a sequence of intracellular protein-protein interactions, leading to the production of proteins which modify their fundamental operations.  ...  When using IS in place of the exact E-step, one is confronted with the question: what number of samples, L, is sufficient?  ...  Determining the global optimum would require exhaustive search which is also computationally intractable.  ... 
doi:10.1109/icassp.2007.366694 dblp:conf/icassp/RabbatFN07 fatcat:smh6pbazdvghjg2gvecpu5r6z4

Computing Bayes: From Then 'Til Now' [article]

Gael M. Martin, David T. Frazier, Christian P. Robert
2022 arXiv   pre-print
Beginning with the one-dimensional integral first confronted by Bayes in 1763, we highlight the key contributions of: Laplace, Metropolis (and, importantly, his co-authors!)  ...  , x, in addition to the smaller set of 'global' (or 'hyperparameters) parameters, θ.  ...  Exact solutions still invoke MCMC or IS principles to compute (4) in cases where one or more form of intractability obtains.  ... 
arXiv:2208.00646v1 fatcat:ewptq7piwbhatalturjvtnms7y

Use of a portable head mounted perimetry system to assess bedside visual fields

D A Hollander
2000 British Journal of Ophthalmology  
Each of the 11 fields (100%) classified with defects on confrontation testing was similarly categorised on head mounted perimetry. 26 out of 31 (84%) visual fields were normal on both confrontation and  ...  The patterns of visual field defects were categorised and compared with the results of confrontation testing.  ...  Via the individual screens in front of each eye, the headset provides the patients with a binocular view ( Fig 1) .  ... 
doi:10.1136/bjo.84.10.1185 pmid:11004108 pmcid:PMC1723249 fatcat:rnexvbosbvam3d5k7jwrxyaa2i

Accounting for sample selection in Bayesian analyses [article]

Samuel R. Hinton, Alex Kim, Tamara M. Davis
2017 arXiv   pre-print
In this paper we present a simple overview of a Bayesian consideration of sample selection, giving solutions to both analytically tractable and intractable models.  ...  Astronomers are often confronted with funky populations and distributions of objects: brighter objects are more likely to be detected; targets are selected based on colour cuts; imperfect classification  ...  The bias shown in the red 'Biased' contour can be corrected to via the techniques shown in Section 3.2 to recover unbiased surfaces.  ... 
arXiv:1706.03856v2 fatcat:kauboaeszjeknf5ofi7cdkdplq

Probabilistic Planning with Reduced Models

Luis Pineda
2014 PROCEEDINGS OF THE THIRTIETH AAAI CONFERENCE ON ARTIFICIAL INTELLIGENCE AND THE TWENTY-EIGHTH INNOVATIVE APPLICATIONS OF ARTIFICIAL INTELLIGENCE CONFERENCE  
However, solving MDPs is often intractable, which has led to the development of many approximate algorithms.  ...  In my dissertation work I introduce a new paradigm to handle this complexity by defining a family of MDP reduced models characterized by two parameters: the maximum number of primary outcomes per action  ...  The advantage of this approach is its ability to quickly generate partial plans, particularly in intractable probabilistic domains.  ... 
doi:10.1609/aaai.v28i1.8775 fatcat:36lsyqu27veork3cnsjcu55ohi

Approximating Bayes in the 21st Century [article]

Gael M. Martin, David T. Frazier, Christian P. Robert
2021 arXiv   pre-print
Such methods produce computational solutions to certain intractable statistical problems that challenge exact methods like Markov chain Monte Carlo: for instance, models with unavailable likelihoods, high-dimensional  ...  Being able to tackle intractable problems via an approximate method without compromising predictive accuracy is an attractive prospect for investigators, and suggests that approximate computation may play  ...  In such cases, the computational cost of simulating from p(θ|y), via MCMC for example, may simply be prohibitive, given the need to both explore a high-dimensional and complex parameter space and -at each  ... 
arXiv:2112.10342v1 fatcat:225euaxkqrcjzals2jluqrocbu
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