3,249 research outputs found
A New Approximation Technique for Resource-Allocation Problems
We develop a rounding method based on random walks in polytopes, which leads
to improved approximation algorithms and integrality gaps for several
assignment problems that arise in resource allocation and scheduling. In
particular, it generalizes the work of Shmoys and Tardos on the generalized
assignment problem to the setting where some jobs can be dropped. New
concentration bounds for random bipartite matching are developed as well.Comment: Journal version in Random Structures & Algorithms, Conference version
in Proceedings of Innovations in Computer Science (ICS) 201
Evo* 2020 -- Late-Breaking Abstracts Volume
This volume contains the Late-Breaking Abstracts submitted to the Evo* 2020
Conference, that took place online, from 15 to 17 of April 2020. These papers
where presented as short talks and also at the poster session of the conference
together with other regular submissions. All of them present ongoing research
and preliminary results investigating on the application of different
approaches of Bioinspired Methods (mainly Evolutionary Computation) to
different problems, most of them real world ones.Comment: LBAs accepted in Evo* 2020. Part of the Conference Proceeding
The Anatomy of Large-Scale Distributed Graph Algorithms
The increasing complexity of the software/hardware stack of modern
supercomputers results in explosion of parameters. The performance analysis
becomes a truly experimental science, even more challenging in the presence of
massive irregularity and data dependency. We analyze how the existing body of
research handles the experimental aspect in the context of distributed graph
algorithms (DGAs). We distinguish algorithm-level contributions, often
prioritized by authors, from runtime-level concerns that are harder to place.
We show that the runtime is such an integral part of DGAs that experimental
results are difficult to interpret and extrapolate without understanding the
properties of the runtime used. We argue that in order to gain understanding
about the impact of runtimes, more information needs to be gathered. To begin
this process, we provide an initial set of recommendations for describing DGA
results based on our analysis of the current state of the field
Towards Bin Packing (preliminary problem survey, models with multiset estimates)
The paper described a generalized integrated glance to bin packing problems
including a brief literature survey and some new problem formulations for the
cases of multiset estimates of items. A new systemic viewpoint to bin packing
problems is suggested: (a) basic element sets (item set, bin set, item subset
assigned to bin), (b) binary relation over the sets: relation over item set as
compatibility, precedence, dominance; relation over items and bins (i.e.,
correspondence of items to bins). A special attention is targeted to the
following versions of bin packing problems: (a) problem with multiset estimates
of items, (b) problem with colored items (and some close problems). Applied
examples of bin packing problems are considered: (i) planning in paper industry
(framework of combinatorial problems), (ii) selection of information messages,
(iii) packing of messages/information packages in WiMAX communication system
(brief description).Comment: 39 pages, 18 figures, 14 table
08071 Abstracts Collection -- Scheduling
From 10.02. to 15.02., the Dagstuhl Seminar 08071 ``Scheduling\u27\u27 was held
in the International Conference and Research Center (IBFI), Schloss Dagstuhl.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
The 9th Workshop on Models and Algorithms for Planning and Scheduling Problems
This volume contains extended abstracts of papers presented at the 9th Worksho
Recommended from our members
Constant-time cost evaluation for behavioral partitioning
Given a system behavioral specification, partitioning can be used to distribute among chips the processes, procedures, and storage elements that comprise the specification. We introduce a technique for constant-time recomputation of pin, area, and execution-time estimates for a behavioral partitioning move. The technique permits fast, accurate estimations of a large number of partitionings, thus enabling better results than approaches which attain tractable computation time by using gross estimates or less thorough partitioning algorithms. The key to our technique is the isolation and extraction before partitioning of the basic design attributes needed for estimation, and the updating of this information in constant-time for each move. The estimation models are almost as detailed as those presented in previous estimation approaches not intended for constant-time update. The results we provide indicate the speed and practicality of our estimation approach in conjunction with sophisticated partitioning algorithms
Approximate and Incremental Network Function Placement
The virtualization and softwarization of modern computer networks introduces
interesting new opportunities for a more flexible placement of network
functions and middleboxes (firewalls, proxies, traffic optimizers, virtual
switches, etc.). This paper studies approximation algorithms for the
incremental deployment of a minimum number of middleboxes at optimal locations,
such that capacity constraints at the middleboxes and length constraints on the
communication routes are respected. Our main contribution is a new, purely
combinatorial and rigorous proof for the submodularity of the function
maximizing the number of communication requests that can be served by a given
set of middleboxes. Our proof allows us to devise a deterministic approximation
algorithm which uses an augmenting path approach to compute the submodular
function. This algorithm does not require any changes to the locations of
existing middleboxes or the preemption of previously served communication pairs
when additional middleboxes are deployed, previously accepted communication
pairs just can be handed over to another middlebox. It is hence particularly
attractive for incremental deployments.We prove that the achieved
polynomial-time approximation bound is optimal, unless P = NP. This paper also
initiates the study of a weighted problem variant, in which entire groups of
nodes need to communicate via a middlebox (e.g., a multiplexer or a shared
object), possibly at different rates. We present an LP relaxation and
randomized rounding algorithm for this problem, leveraging an interesting
connection to scheduling
Local search in physical distribution management
Physical distribution management presents a variety of decision making problems at three levels of strategic, tactical and operational planning. The importance of effective and efficient distribution management is evident from its associated costs. Physical distribution management at the operational level, which is considered in this paper is responsible for an important fraction of the total distribution costs. Not surprisingly, there is a growing demand for planning systems that produce economical routes. Enormous theoretical as well as practical advances have been made, in the last decade. Some of the resulting vehicle and scheduling models will be discussed in this paper, like vehicle routing problem with time window and the pickup and delivery problem with time window
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