scholarly journals Efficient Temporal Planning Using Metastates

2019 ◽  
Vol 33 ◽  
pp. 7554-7561 ◽  
Author(s):  
Amanda Coles ◽  
Andrew Coles ◽  
J. Christopher Beck
Keyword(s):  
State Space ◽  
State Of The Art ◽  
The State ◽  
The Other ◽  
Temporal Constraints ◽  
State Space Explosion ◽  
Temporal Planning ◽  
State Space Search ◽  
Temporal Inconsistency

When performing temporal planning as forward state-space search, effective state memoisation is challenging. Whereas in classical planning, two states are equal if they have the same facts and variable values, in temporal planning this is not the case: as the plans that led to the two states are subject to temporal constraints, one might be extendable into at temporally valid plan, while the other might not. In this paper, we present an approach for reducing the state space explosion that arises due to having to keep many copies of the same ‘classically’ equal state – states that are classically equal are aggregated into metastates, and these are separated lazily only in the case of temporal inconsistency. Our evaluation shows that this approach, implemented in OPTIC and compared to existing state-of-the-art memoisation techniques, improves performance across a range of temporal domains.

scholarly journals ITSAT: An Efficient SAT-Based Temporal Planner

2015 ◽  
Vol 53 ◽  
pp. 541-632 ◽  
Author(s):  
Masood Feyzbakhsh Rankooh ◽  
Gholamreza Ghassem-Sani
Keyword(s):  
State Space ◽  
State Of The Art ◽  
Relation Extraction ◽  
The State ◽  
Parallel Execution ◽  
Temporal Constraints ◽  
Continuous Variables ◽  
Temporal Planning ◽  
Execution Semantics ◽  
Planning Problems

Planning as satisfiability is known as an efficient approach to deal with many types of planning problems. However, this approach has not been competitive with the state-space based methods in temporal planning. This paper describes ITSAT as an efficient SAT-based (satisfiability based) temporal planner capable of temporally expressive planning. The novelty of ITSAT lies in the way it handles temporal constraints of given problems without getting involved in the difficulties of introducing continuous variables into the corresponding satisfiability problems. We also show how, as in SAT-based classical planning, carefully devised preprocessing and encoding schemata can considerably improve the efficiency of SAT-based temporal planning. We present two preprocessing methods for mutex relation extraction and action compression. We also show that the separation of causal and temporal reasoning enables us to employ compact encodings that are based on the concept of parallel execution semantics. Although such encodings have been shown to be quite effective in classical planning, ITSAT is the first temporal planner utilizing this type of encoding. Our empirical results show that not only does ITSAT outperform the state-of-the-art temporally expressive planners, it is also competitive with the fast temporal planners that cannot handle required concurrency.

scholarly journals Density Guarantee on Finding Multiple Subgraphs and Subtensors

2021 ◽  
Vol 15 (5) ◽  
pp. 1-32
Author(s):  
Quang-huy Duong ◽  
Heri Ramampiaro ◽  
Kjetil Nørvåg ◽  
Thu-lan Dam
Keyword(s):  
Lower Bound ◽  
State Of The Art ◽  
The State ◽  
The Other ◽  
Exact Methods ◽  
Practical Solution ◽  
Novel Approach ◽  
Wide Range ◽  
Real World Datasets ◽  
Tensor Data

Dense subregion (subgraph & subtensor) detection is a well-studied area, with a wide range of applications, and numerous efficient approaches and algorithms have been proposed. Approximation approaches are commonly used for detecting dense subregions due to the complexity of the exact methods. Existing algorithms are generally efficient for dense subtensor and subgraph detection, and can perform well in many applications. However, most of the existing works utilize the state-or-the-art greedy 2-approximation algorithm to capably provide solutions with a loose theoretical density guarantee. The main drawback of most of these algorithms is that they can estimate only one subtensor, or subgraph, at a time, with a low guarantee on its density. While some methods can, on the other hand, estimate multiple subtensors, they can give a guarantee on the density with respect to the input tensor for the first estimated subsensor only. We address these drawbacks by providing both theoretical and practical solution for estimating multiple dense subtensors in tensor data and giving a higher lower bound of the density. In particular, we guarantee and prove a higher bound of the lower-bound density of the estimated subgraph and subtensors. We also propose a novel approach to show that there are multiple dense subtensors with a guarantee on its density that is greater than the lower bound used in the state-of-the-art algorithms. We evaluate our approach with extensive experiments on several real-world datasets, which demonstrates its efficiency and feasibility.

scholarly journals Coinductive Algorithms for Büchi Automata

2021 ◽  
Vol 180 (4) ◽  
pp. 351-373
Author(s):  
Denis Kuperberg ◽  
Laureline Pinault ◽  
Damien Pous
Keyword(s):  
State Space ◽  
State Of The Art ◽  
The State ◽  
Specific Structure ◽  
Büchi Automata ◽  
Deterministic Automata ◽  
Buchi Automata ◽  
Language Equivalence ◽  
Art Techniques

We propose a new algorithm for checking language equivalence of non-deterministic Büchi automata. We start from a construction proposed by Calbrix, Nivat and Podelski, which makes it possible to reduce the problem to that of checking equivalence of automata on finite words. Although this construction generates large and highly non-deterministic automata, we show how to exploit their specific structure and apply state-of-the art techniques based on coinduction to reduce the state-space that has to be explored. Doing so, we obtain algorithms which do not require full determinisation or complementation.

The State of the Art in Management Education Applicable to Aerospace Activities

1967 ◽  
Vol 71 (677) ◽  
pp. 342-343
Author(s):  
F. H. East
Keyword(s):  
Research And Development ◽  
Management Education ◽  
State Of The Art ◽  
Development Project ◽  
The State ◽  
The Other ◽  
The Past ◽  
Defence Budget ◽  
The One ◽  
Almost All

The Aviation Group of the Ministry of Technology (formerly the Ministry of Aviation) is responsible for spending a large part of the country's defence budget, both in research and development on the one hand and production or procurement on the other. In addition, it has responsibilities in many non-defence fields, mainly, but not exclusively, in aerospace.Few developments have been carried out entirely within the Ministry's own Establishments; almost all have required continuous co-operation between the Ministry and Industry. In the past the methods of management and collaboration and the relative responsibilities of the Ministry and Industry have varied with time, with the type of equipment to be developed, with the size of the development project and so on. But over the past ten years there has been a growing awareness of the need to put some system into the complex business of translating a requirement into a specification and a specification into a product within reasonable bounds of time and cost.

The State of the Art in Management Studies Applicable to Aerospace Activities

1967 ◽  
Vol 71 (677) ◽  
pp. 338-342
Author(s):  
G. P. Dollimore
Keyword(s):  
State Of The Art ◽  
Integrated Management ◽  
The State ◽  
The Other ◽  
Medium Size ◽  
General Management ◽  
Management Techniques ◽  
A Company

Perhaps I should start as earlier speakers have done with a disclaimer to the effect that I am not putting my thoughts forward as those of an expert in all fields of management. I am perhaps fortunate in having been concerned with projects which lend themselves to experiments in the use of integrated management techniques, and also in the operation of a company which, because of its medium size—a thousand or so strong—and its type of business, is just large enough on one hand to justify a reasonably sophisticated approach to general management and, on the other, small enough for one to see the effects of changes in approach. It is on this basis that I shall make my comments.

Review of Hill (2019): The Historical Phonology of Tibetan, Burmese, and Chinese

2020 ◽  
Vol 46 (2) ◽  
pp. 299-311
Author(s):  
Giorgio (Georg) Orlandi
Keyword(s):  
Significant Contribution ◽  
State Of The Art ◽  
The State ◽  
The Other ◽  
General Introduction ◽  
Historical Phonology ◽  
Shared History ◽  
Systematic Exploration ◽  
History Of ◽  
The One

Abstract The book under review serves as a significant contribution to the field of Trans-Himalayan linguistics. Designed as a vade mecum for readers with little linguistic background in these three languages, Nathan W. Hill’s work attempts, on the one hand, a systematic exploration of the shared history of Burmese, Tibetan and Chinese, and, on the other, a general introduction to the reader interested in obtaining an overall understanding of the state of the art of the historical phonology of these three languages. Whilst it is acknowledged that the book in question has the potential to be a solid contribution to the field, it is also felt that few minor issues can be also addressed.

PROPOSED MODIFICATIONS TO PARALLEL STATE SPACE SEARCH OF GAME TREES

1991 ◽  
Vol 05 (05) ◽  
pp. 809-833 ◽  
Author(s):  
RAJIAN SHINGHAL ◽  
SOFIA SHVED
Keyword(s):  
State Space ◽  
Search Algorithms ◽  
The Other ◽  
State Space Search ◽  
Game Trees ◽  
Pruning Algorithms ◽  
Better Than

Modifications have been proposed to state space search algorithms for pruning game trees in parallel.The performance of these modified algorithms is empirically shown to be better than the other known parallel pruning algorithms.

scholarly journals الكتابة اللسانية العربية من الرؤية الغربية إلى التأصيل الإسلامي للمنهج: قراءة وصفية في صور التلقي ونماذج الصياغة (The writing of Arabic linguistic from the western perspective until the attempt to establish the Islamic origin of its method)

1970 ◽  
Vol 1 (1) ◽  
Author(s):  
نعمان عبد الحميد (Nu'man Abdel Hamid Buqirah)
Keyword(s):  
State Of The Art ◽  
Arab World ◽  
The State ◽  
The Other ◽  
Development Method ◽  
Arabic Linguistics ◽  
Essential Question ◽  
Continuous Interaction ◽  
Western Perspective ◽  
Islamic View

ملخص البحث:تتنزل هذه الدراسة التي تصف أهم الدراسات العربية التي حاولت شرح النظرية اللسانية الغربية، وعرضها، والتعريف بأهم مبادئها واستثمارها في دراسة النحو العربي في سياق تمثل الآخر منهجيا ومعرفيا، قصد بلورة اللحظة الراهنة في الثقافة اللسانية العربية المعاصرة. والدراسة تستأنف أيضاً السؤال المحوري الذي تنزع إليه هذه الندوة وهو إلى  أي مدى يمكن أن نعيد طرح الأسئلة اللغوية الحاسمة التي ينهض عليها الفكر اللساني من زاوية إسلامية  تنطلق من تصور القرآن الكريم والسنة النبوية، ولعل هذا المسعى البحثي على إيجازه يحاول رصد حركة التغير المنهجي في صياغة المنظومة اللسانية التي واكبت تطور البحث في شؤون اللغة في المشرق العربي ومغربه مما يمكن من مدّ جسور أخرى للحوار مع الآخر قصد المشاركة الفعالة في بلورة إطار علمي يخدم قضايا التنمية اللغوية. الكلمات المفتاحية: النشأة- المنهج- المعرفة- المتوكل-الفهري. Abstract:This study focuses  to describe the most important Arabic linguistic studies that were based on western perspective with regard to their principles and applicability on the study of Arabic grammar in the context of “the representation of the other” in its method. The paper aims to explain the state of the art of the discipline in the field of Arabic linguistics. It deals with an essential question: to what extend can we still apply the Islamic view of language based on the holy Koran and the prophetic tradition on the current discipline? It is hoped that this study will provide the accounts for the development of the change of methodology in presenting the study of language in the Arab world that would enable a continuous interaction with other cultures to actively engage them in the context of discussing the issues related to language development.Keywords: Development- method- al-Mutawakkil- al-Fahri. Abstrak:Kajian ini membincangkan satu ilmu yang penting dalam bidang bahasa Arab iaitu teori linguistik barat dan prinsip-prinsipnya seterusnya melihat sejauh mana ia dapat diaplikasikan ke dalam kajian Nahu bahasa  Arab dari segi pengetahuan dan metodologi dengan hasrat untuk mendedahkan linguistik Arab Moden kepada isu- isu semasa dan terkini. Kajian ini  juga cuba membahaskan persoalan utama yang dibangkitkan oleh golongan barat tentang sejauh mana kita boleh melontarkan persoalan- persoalan mengenai bahasa yang menggalakkan pemikiran kritis menurut persepsi islam yang bersandarkan Al-Quran dan sunnah. Di samping itu, usaha daripada kajian yang ringkas ini diharapkan dapat membentuk satu pergerakan yang bakal mengubah sistem dan kaedah kajian linguistik Arab supaya lebih sistematik dan mengikuti arus dunia penyelidikan yang terkini. Justeru ia dapat dijadikan jambatan kepada perbincangan dengan dunia luar dan  membina kerjasama yang lebih efektif dalam bidang penyelidikan khusus untuk pembangunan bahasa.Kata kunci: Penubuhan – Metodologi – Pengetahuan -  Al-Mutawakkil – Al-Fahri. 

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