Emptiness Problem Research Articles

Implementation Of Green Economy In Apartment Building In Surabaya

Approach to urban green economy to apartment buildings. Surabaya is the largestmetropolitan city in East Java Province and the capital of the province. By population, it isthe second largest city in Indonesia after Jakarta. According to data from the Surabaya CityCentral Statistics Office (BPS), Surabaya's population is currently growing rapidly, and isexpected to have more than 2 million residents by 2021. With faster population growth, theactivity population also becomes more productive. Aside from growing populationactivities, the need for housing is also growing and is becoming a problem, especially inurban areas. The high cost of land and the shrinking number of vacant lots make it hard forimmigrants and local communities to buy houses or land in Surabaya. Therefore, a verticalhousing concept or apartment is needed to solve the expensive and difficult problem ofempty land in Surabaya. The concept of green city development emerged as a result of thisproblem. A network or system of urban green building uses nature to reduce or cope withurban issues and climate change.

Decomposing Temporal Equilibrium Strategy for Coordinated Distributed Multi-Agent Reinforcement Learning

The increasing demands for system complexity and robustness have prompted the integration of temporal logic into Multi-Agent Reinforcement Learning (MARL) to address tasks with non-Markovian properties. However, incorporating non-Markovian properties introduces additional computational complexities, as agents are required to integrate historical data into their decision-making process. Also, optimizing strategies within a multi-agent environment presents significant challenges due to the exponential growth of the state space with the number of agents. In this study, we introduce an innovative hierarchical MARL framework that synthesizes temporal equilibrium strategies through parity games and subsequently encodes them as individual reward machines for MARL coordination. More specifically, we reduce the strategy synthesis problem into an emptiness problem concerning parity games with optimized states and transitions. Following this synthesis step, the temporal equilibrium strategy is decomposed into individual reward machines for decentralized MARL. Theoretical proofs are provided to verify the consistency of the Nash equilibrium between the parallel composition of decomposed strategies and the original strategy. Empirical evidence confirms the efficacy of the proposed synthesis technique, showcasing its ability to reduce state space compared to the state-of-the-art tool. Furthermore, our study highlights the superior performance of the distributed MARL paradigm over centralized approaches when deploying decomposed strategies.

Complexity of the emptiness problem for graph-walking automata and for tilings with star subgraphs

This paper proves the decidability of the emptiness problem for two models which recognize finite graphs: graph-walking automata, and tilings of graphs by star subgraphs (star automata). Furthermore, it is proved that the non-emptiness problem for graph-walking automata (that is, whether a given automaton accepts at least one graph) is NEXP-complete. For star automata, which generalize nondeterministic tree automata to the case of graphs, it is proved that their non-emptiness problem is NP-complete.

Uniform Restricted Chase Termination

The chase procedure is a fundamental algorithmic tool in database theory with a variety of applications. A central problem concerning the chase procedure is uniform (a.k.a. all-instances) chase termination: for a given set of tuple-generating dependencies (TGDs), is it the case that the chase terminates for every input database? In view of the fact that this problem is, in general, undecidable, it is natural to ask whether known well-behaved classes of TGDs ensure decidability. We focus on the main paradigms that led to robust TGD-based formalisms, namely guardedness and stickiness, that have been introduced in the context of knowledge-enriched databases. Although uniform chase termination is well understood for the oblivious version of the chase (2EXPTIME-complete for guarded, and PSPACE-complete for sticky TGDs), the more subtle case of the restricted (a.k.a. the standard) chase is rather unexplored. We show that uniform restricted chase termination under guarded single-head TGDs and sticky single-head TGDs is decidable in elementary time. In the case of guardedness, we provide a reduction to the satisfiability problem of monadic second-order logic over infinite trees of bounded degree, while for stickiness we provide a reduction to the emptiness problem of deterministic Büchi automata. Those reductions build on a series of technical results of independent interest related to the notion of fairness of the restricted chase, and the existence of critical databases that characterize nontermination of the restricted chase via databases of a certain form.

A Subclass of Mu-Calculus with the Freeze Quantifier Equivalent to Register Automata

Register automaton (RA) is an extension of finite automaton by adding registers storing data values. RA has good properties such as the decidability of the membership and emptiness problems. Linear temporal logic with the freeze quantifier (LTL↓) proposed by Demri and Lazić is a counterpart of RA. However, the expressive power of LTL↓ is too high to be applied to automatic verification. In this paper, we propose a subclass of modal µ-calculus with the freeze quantifier, which has the same expressive power as RA. Since a conjunction ψ1 ∧ ψ2 in a general LTL↓ formula cannot be simulated by RA, the proposed subclass prohibits at least one of ψ1 and ψ2 from containing the freeze quantifier or a temporal operator other than X (next). Since the obtained subclass of LTL↓ does not have the ability to represent a cycle in RA, we adopt µ-calculus over the subclass of LTL↓, which allows recursive definition of temporal formulas. We provide equivalent translations from the proposed subclass of µ-calculus to RA and vice versa and prove their correctness.

Integer Weighted Automata on Infinite Words

In this paper we combine two classical generalisations of finite automata (weighted automata and automata on infinite words) into a model of integer weighted automata on infinite words and study the universality and the emptiness problems under zero weight acceptance. We show that the universality problem is undecidable for three-state automata by a direct reduction from the infinite Post correspondence problem. We also consider other more general acceptance conditions as well as their complements with respect to the universality and the emptiness problems. Additionally, we build a universal integer weighted automaton with fixed transitions. This automaton has an additional integer input that allows it to simulate any semi-Thue system.

Adversarial Formal Semantics of Attack Trees and Related Problems

Security is a subject of increasing attention in our actual society in order to protect critical resources from information disclosure, theft or damage. The informal model of attack trees introduced by Schneier, and widespread in the industry, is advocated in the 2008 NATO report to govern the evaluation of the threat in risk analysis. Attack-defense trees have since been the subject of many theoretical works addressing different formal approaches. In 2017, M. Audinot et al. introduced a path semantics over a transition system for attack trees. Inspired by the later, we propose a two-player interpretation of the attack-tree formalism. To do so, we replace transition systems by concurrent game arenas and our associated semantics consist of strategies. We then show that the emptiness problem, known to be NP-complete for the path semantics, is now PSPACE-complete. Additionally, we show that the membership problem is coNP-complete for our two-player interpretation while it collapses to P in the path semantics.

On the decidability of finding a positive ILP-instance in a regular set of ILP-instances

The regular intersection emptiness problem for a decision problem P ({{textit{int}}_{{mathrm {Reg}}}}(P)) is to decide whether a potentially infinite regular set of encoded P-instances contains a positive one. Since {{textit{int}}_{{mathrm {Reg}}}}(P) is decidable for some NP-complete problems and undecidable for others, its investigation provides insights in the nature of NP-complete problems. Moreover, the decidability of the {{textit{int}}_{{mathrm {Reg}}}}-problem is usually achieved by exploiting the regularity of the set of instances; thus, it also establishes a connection to formal language and automata theory. We consider the {{textit{int}}_{{mathrm {Reg}}}}-problem for the well-known NP-complete problem Integer Linear Programming (ILP). It is shown that any DFA that describes a set of ILP-instances (in a natural encoding) can be reduced to a finite core of instances that contains a positive one if and only if the original set of instances did. This result yields the decidability of {{textit{int}}_{{mathrm {Reg}}}}(ILP).

Parallel computational tree logic model‐checking on pushdown systems

SummaryModel checking and static analysis have been well studied for program verification. Because of the ability to describe the stack, the pushdown system (PDS) has become a perfect model that is able to accurately model procedure calls and mimic the program's stack. Thus, it is not only a good model for sequential programs but for malware detection as well. However, with the increase of the complexity of programs, the size of models becomes huge as well. Thus, the model‐checking problem is expensive to solve. The computational tree logic (CTL) is a widely used logic and its model checking problem of PDSs can be reduced to the emptiness analysis of an alternating Büchi pushdown system (ABPDS) by determining whether there is an accepting run. When the size of a PDS is huge, the computations can be time‐consuming. To overcome this limitation, we propose a parallel solution. We propose a parallel framework based on the Compute Unified Device Architecture and the corresponding parallel algorithms to solve the emptiness problem of ABPDSs. Moreover, in order to effectively utilize the graphics processing unit, we design a new data structure of variables and an algorithm of management of thread scheduling for the parallel model. We implement our algorithms in a tool and compare our tool to a CTL model checker for PDS as a benchmark. The comparison results indicate an encouraging performance speedup.

Trial Proving in Electronic Criminal Case Trial Based On the Dignified Justice Perspective

Trial proving in Indonesia has always been limited to Criminal Procedural Law and other regulations. Following the recent development of electronic criminal case trials, there has not been any precise regulation aside from Supreme Court Regulation 4 of 2020. The contradiction between KUHAP and Supreme Court Regulation causes problems, especially regarding trial proving. The purpose of the paper is to provide a legal solution to the problem of the legal emptiness regarding the regulation of trial proving in electronic criminal case trials from the perspective of Dignified Justice that will provide advantageous, responsive, and adaptive justice towards the needs of the community. The methodology of this research is based on normative research. The normative research methods used in this research are the statute, normative, and comparative approaches. The result shown there shouldn't be a conflict between the effect of KUHAP and Supreme Court Regulation. Yet, the regulation of trial proving in an electronic criminal trial should be regulated at a statute level.

Complexity results on register context-free grammars and related formalisms

Register context-free grammars (RCFG), register pushdown automata (RPDA) and register tree automata (RTA) are extensions of their classical counterparts to handle data values in a restricted way. These extended models are paid attention as models of query languages for structured documents such as XML with data values. This paper investigates the computational complexity of the basic decision problems for the models. We show that the membership and emptiness problems for RCFG are EXPTIME-complete and also show the membership problem becomes PSPACE-complete and NP-complete for ε-rule free RCFG and growing RCFG, respectively while the emptiness problem remains EXPTIME-complete for these subclasses. The complexities of these problems for RPDA and RTA as well as their language expressive powers are also investigated.

LTL model checking of self modifying code

Self modifying code is code that can modify its own instructions during the execution of the program. It is extensively used by malware writers to obfuscate their malicious code. Thus, analysing self modifying code is nowadays a big challenge. In this paper, we consider the LTL model-checking problem of self modifying code. We model such programs using self-modifying pushdown systems, an extension of pushdown systems that can modify its own set of transitions during execution. We reduce the LTL model-checking problem to the emptiness problem of self-modifying Büchi pushdown systems. We implemented our techniques in a tool that we successfully applied for the detection of several self-modifying malware. Our tool was also able to detect several malwares that well-known antiviruses such as BitDefender, Kinsoft, Avira, eScan, Kaspersky, Qihoo-360, Baidu, Avast, and Symantec failed to detect.

Register Automata with Extrema Constraints, and an Application to Two-Variable Logic

We introduce a model of register automata over infinite trees with extrema constraints. Such an automaton can store elements of a linearly ordered domain in its registers, and can compare those values to the suprema and infima of register values in subtrees. We show that the emptiness problem for these automata is decidable. As an application, we prove decidability of the countable satisfiability problem for two-variable logic in the presence of a tree order, a linear order, and arbitrary atoms that are MSO definable from the tree order. As a consequence, the satisfiability problem for two-variable logic with arbitrary predicates, two of them interpreted by linear orders, is decidable.

Polynomially ambiguous probabilistic automata on restricted languages

We consider the computability and complexity of decision questions for Probabilistic Finite Automata (PFA) with sub-exponential ambiguity. We show that the emptiness problem for strict and non-strict cut-points of polynomially ambiguous commutative PFA remains undecidable, implying that the problem is undecidable when inputs are from a letter monotonic language. We show that the problem remains undecidable over a binary input alphabet when the input word is over a bounded language, in the noncommutative case. In doing so, we introduce a new technique based upon the Turakainen construction of a PFA from a Weighted Finite Automaton which can be used to generate PFA of lower dimensions and of sub-exponential ambiguity. We also study freeness/injectivity problems for polynomially ambiguous PFA and study the border of decidability and tractability for various cases.

Reachability and liveness in parametric timed automata

We study timed systems in which some timing features are unknown parameters. Parametric timed automata (PTAs) are a classical formalism for such systems but for which most interesting problems are undecidable. Notably, the parametric reachability emptiness problem, i.e., the emptiness of the parameter valuations set allowing to reach some given discrete state, is undecidable. Lower-bound/upper-bound parametric timed automata (L/U-PTAs) achieve decidability for reachability properties by enforcing a separation of parameters used as upper bounds in the automaton constraints, and those used as lower bounds. In this paper, we first study reachability. We exhibit a subclass of PTAs (namely integer-points PTAs) with bounded rational-valued parameters for which the parametric reachability emptiness problem is decidable. Using this class, we present further results improving the boundary between decidability and undecidability for PTAs and their subclasses such as L/U-PTAs. We then study liveness. We prove that: (1) deciding the existence of at least one parameter valuation for which there exists an infinite run in an L/U-PTA is PSpace-complete; (2) the existence of a parameter valuation such that the system has a deadlock is however undecidable; (3) the problem of the existence of a valuation for which a run remains in a given set of locations exhibits a very thin border between decidability and undecidability.

On the Satisfiability and Model Checking for one Parameterized Extension of Linear-time Temporal Logic

Sequential reactive systems are computer programs or hardware devices which process the flows of input data or control signals and output the streams of instructions or responses. When designing such systems one needs formal specification languages capable of expressing the relationships between the input and output flows. Previously, we introduced a family of such specification languages based on temporal logics $LTL$, $CTL$ and $CTL^*$ combined with regular languages. A characteristic feature of these new extensions of conventional temporal logics is that temporal operators and basic predicates are parameterized by regular languages. In our early papers, we estimated the expressive power of the new temporal logic $Reg$-$LTL$ and introduced a model checking algorithm for $Reg$-$LTL$, $Reg$-$CTL$, and $Reg$-$CTL^*$. The main issue which still remains unclear is the complexity of decision problems for these logics. In the paper, we give a complete solution to satisfiability checking and model checking problems for $Reg$-$LTL$ and prove that both problems are Pspace-complete. The computational hardness of the problems under consideration is easily proved by reducing to them the intersection emptyness problem for the families of regular languages. The main result of the paper is an algorithm for reducing the satisfiability of checking $Reg$-$LTL$ formulas to the emptiness problem for Buchi automata of relatively small size and a description of a technique that allows one to check the emptiness of the obtained automata within space polynomial of the size of input formulas.

A localization strategy combined with transfer learning for image annotation.

This study aims to solve the overfitting problem caused by insufficient labeled images in the automatic image annotation field. We propose a transfer learning model called CNN-2L that incorporates the label localization strategy described in this study. The model consists of an InceptionV3 network pretrained on the ImageNet dataset and a label localization algorithm. First, the pretrained InceptionV3 network extracts features from the target dataset that are used to train a specific classifier and fine-tune the entire network to obtain an optimal model. Then, the obtained model is used to derive the probabilities of the predicted labels. For this purpose, we introduce a squeeze and excitation (SE) module into the network architecture that augments the useful feature information, inhibits useless feature information, and conducts feature reweighting. Next, we perform label localization to obtain the label probabilities and determine the final label set for each image. During this process, the number of labels must be determined. The optimal K value is obtained experimentally and used to determine the number of predicted labels, thereby solving the empty label set problem that occurs when the predicted label values of images are below a fixed threshold. Experiments on the Corel5k multilabel image dataset verify that CNN-2L improves the labeling precision by 18% and 15% compared with the traditional multiple-Bernoulli relevance model (MBRM) and joint equal contribution (JEC) algorithms, respectively, and it improves the recall by 6% compared with JEC. Additionally, it improves the precision by 20% and 11% compared with the deep learning methods Weight-KNN and adaptive hypergraph learning (AHL), respectively. Although CNN-2L fails to improve the recall compared with the semantic extension model (SEM), it improves the comprehensive index of the F1 value by 1%. The experimental results reveal that the proposed transfer learning model based on a label localization strategy is effective for automatic image annotation and substantially boosts the multilabel image annotation performance.

On computational complexity of set automata

We consider a computational model which is known as set automata.The set automata are one-way finite automata with additional storage—the set. There are two kinds of set automata—deterministic (DSA's) and nondeterministic (NSA's). The model was introduced by Kutrib, Malcher, Wendlandt in 2014. It was shown that DSA-recognizable languages look similar to DCFL's and NSA-recognizable languages look similar to CFL's.In this paper, we extend this similarity and prove that languages recognizable by NSA's form a rational cone, as do CFL's.The main topic of this paper is computational complexity: we prove that–languages recognizable by DSA's belong to P and there are P-complete languages among them;–languages recognizable by NSA's are in NP and there are NP-complete languages among them;–the word membership problem is P-complete for DSA's without ε-loops and PSPACE-complete for general DSA's;–the emptiness problem is PSPACE-complete for DSA's.

Tele-kiss. Nam-June Paik’s expanded media in the light of Zen Buddhism


 
 
 The article offers a broad overview of Nam-June Paik’s ideas of the expansion of video arts interpreted in the light of Zen Buddhism. His works recognized as the most significant examples of his marriage between the art theory and practice are marked by a thought-provoking vision of participatory culture, communicated in-between the networks in the post-industrial society. Our purpose is to reexamine his attitude to TV culture in the oscillation between Western and Eastern gaze considered in connection to the problems of emptiness and meditation drawn from Zen religious beliefs. In discussing his installations there is special stress to reconstruct his inner-insight into the subject of seeing and watching inscribed in a closed-circuit of the communication network.
 
 

When are emptiness and containment decidable for probabilistic automata?

The emptiness and containment problems for probabilistic automata are natural quantitative generalisations of the classical language emptiness and inclusion problems for Boolean automata. It is known that both problems are undecidable. We provide a more refined view of these problems in terms of the degree of ambiguity of probabilistic automata. We show that a gap version of the emptiness problem (known to be undecidable in general) becomes decidable for automata of polynomial ambiguity. We complement this positive result by showing that emptiness remains undecidable when restricted to automata of linear ambiguity. We then turn to finitely ambiguous automata and give a conditional decidability proof for containment in case one of the automata is assumed to be unambiguous. Part of our proof relies on the decidability of the theory of real exponentiation, proved, subject to Schanuel's Conjecture, by Macintyre and Wilkie.