Papers by Phan Thi Cam Tu B1911431
Asian fisheries science, Mar 30, 2022
The increased frequency and intensity of extreme rainfall events attributed to global climate cha... more The increased frequency and intensity of extreme rainfall events attributed to global climate change could lead to changes in salinity and turbidity levels in coastal waters which may negatively impact the survival of organisms, particularly during the early developmental stages. In this study, the influences of salinity and turbidity on the early life stage of Japanese sea cucumber, Apostichopus japonicus (Selenka, 1867), were studied in a series of small-scale laboratory experiments. During the first half of the experiments, A. japonicus fertilised eggs were exposed to various levels of salinity stresses (34: control, 30, 26, 22, 18, 14 PSU) for a single period of 3 h. In the second half of the experiments, following the same duration as the first experiment, fertilised eggs were exposed to different levels of turbidity, 0 (control), 100, 300, 500, and 700 NTU. The results showed that the hatching and survival rates significantly decreased as salinity dropped. As for turbidity, there were significant adverse effects on hatching and survival rates of A. japonicus. This study shows that short-term low salinity and high turbidity influenced events could potentially reduce larvae survival of A. japonicas. These factors could affect the robustness of future adult populations.
Fisheries Science, 2019
The embryonic developmental response of two abalone species (disk abalone Haliotis discus discus,... more The embryonic developmental response of two abalone species (disk abalone Haliotis discus discus, giant abalone Haliotis gigantea) to a drop in salinity with different exposure times was investigated to gain a better understanding of the reasons for the decrease in natural stock populations. Two experimental designs-first, combinations of two salinities (34 and 17 psu) and four exposure times (0, 1, 2 and 4 h), and second, combinations of three salinities (34, 24 and 14 psu) and four exposure times (0, 1, 3 and 6 h)-were tested on disk and giant abalone eggs to determine the effects on hatching onset time, hatching success, percentage of abnormality and survival rate. Hatching onset time increased significantly for both species as salinity dropped and exposure time increased. Both species followed a decreasing trend in terms of hatching success as exposure time increased at low salinity levels. As for abnormality, both species showed a significant negative effect of low salinity and long exposure times. Giant abalone showed better adaptability to long exposure time at low salinity levels, and hence a higher survival rate, than disk abalone.
Journal of Artificial Intelligence Research, 2007
In this paper, we present two alternative approaches to defining answer sets for logic programs w... more In this paper, we present two alternative approaches to defining answer sets for logic programs with arbitrary types of abstract constraint atoms (c-atoms). These approaches generalize the fixpoint-based and the level mapping based answer set semantics of normal logic programs to the case of logic programs with arbitrary types of c-atoms. The results are four different answer set definitions which are equivalent when applied to normal logic programs. The standard fixpoint-based semantics of logic programs is generalized in two directions, called answer set by reduct and answer set by complement. These definitions, which differ from each other in the treatment of negation-as-failure (naf) atoms, make use of an immediate consequence operator to perform answer set checking, whose definition relies on the notion of conditional satisfaction of c-atoms w.r.t. a pair of interpretations. The other two definitions, called strongly and weakly well-supported models, are generalizations of the ...
An approximation of action theories of AC and its application to conformant planning
Lecture Notes in Computer Science, 2005
Techniques for Data Aggregation, Analysis, and Distribution
Developing Agents for Bioinformatics Applications: A Preliminary Design
Parallel and Distributed Processing Techniques and Applications, 2003
Lecture Notes in Computer Science
We describe the development of a constraint logic programming based system, called CPP, which is ... more We describe the development of a constraint logic programming based system, called CPP, which is capable of generating most preferred plans with respect to a user's preference and evaluate its performance.
European Management Review, 2014
Prior work on corruption has largely overlooked personal relationships as an essential determinan... more Prior work on corruption has largely overlooked personal relationships as an essential determinant of bribery incidence in transition economies. In these countries, relationships with public officials are instrumental in enabling transactions and lowering transaction costs, due to incoherent and ever-changing business regulations. Our study examines the impact of personal relationships on bribery incidence in Vietnam, finding that relationships with central government officials decreases the likelihood of bribery, while relationships with local government officials increases the likelihood of bribery. The results provide convincing support for the alleged importance of public-private relationships in contemporary transition economies.
2010 IEEE 26th International Conference on Data Engineering (ICDE 2010), 2010
Information extraction systems are traditionally implemented as a pipeline of special-purpose pro... more Information extraction systems are traditionally implemented as a pipeline of special-purpose processing modules. A major drawback of such an approach is that whenever a new extraction goal emerges or a module is improved, extraction has to be reapplied from scratch to the entire text corpus even though only a small part of the corpus might be affected. In this demonstration proposal, we describe a novel paradigm for information extraction: we store the parse trees output by text processing in a database, and then express extraction needs using queries, which can be evaluated and optimized by databases. Compared with the existing approaches, database queries for information extraction enable generic extraction and minimize reprocessing. However, such an approach also poses a lot of technical challenges, such as language design, optimization and automatic query generation. We will present the opportunities and challenges that we met when building GenerIE, a system that implements this paradigm.
Logic Programming and Nonmonotonic Reasoning, 2003
We present a logic programming based conditional planner that is capable of generating both condi... more We present a logic programming based conditional planner that is capable of generating both conditional plans and conformant plans in the presence of sensing actions and incomplete information. We prove the correctness of our implementation and show that our planner is complete with respect to the 0approximation of sensing actions and the class of conditional plans considered in this paper. Finally, we present preliminary experimental results and discuss further enhancements to the program.
Theory and Practice of Logic Programming, 2007
We extend the 0-approximation of sensing actions and incomplete information in Son and Baral (200... more We extend the 0-approximation of sensing actions and incomplete information in Son and Baral (2001) to action theories with static causal laws and prove its soundness with respect to the possible world semantics. We also show that the conditional planning problem with respect to this approximation isNP-complete. We then present an answer set programming based conditional planner, called ASCP, that is capable of generating both conformant plans and conditional plans in the presence of sensing actions, incomplete information about the initial state, and static causal laws. We prove the correctness of our implementation and argue that our planner is sound and complete with respect to the proposed approximation. Finally, we present experimental results comparing ASCP to other planners.
Lecture Notes in Computer Science, 2005
We report on the development of an agent-based system, called ΦLOG, for the specification and exe... more We report on the development of an agent-based system, called ΦLOG, for the specification and execution of phylogenetic inference applications. We detail the implementation of the main components of the system. In the process, we discuss how advanced techniques developed in different research areas such as domain-specific languages, planning, Web services discovery and invocation, and Web services composition can be applied in the building of the ΦLOG system. Compiler Configuration Component Planning Execution Monitoring
cs.nmsu.edu
The goal of this paper is to demonstrate that parallel programming techniques can boost AI planni... more The goal of this paper is to demonstrate that parallel programming techniques can boost AI planning systems in various aspects. It shows that an appropriate parallelization of a sequential planning system often brings gain in performance and/or scalability. We start by describing general schemes for parallelizing the construction of a plan. We then discuss the applications of these techniques to two domain-independent heuristic search based planners-a competitive conformant planner (CPA) and a state-of-the-art classical planner (FF). We present experimental results which show that performance improvements and scalability are obtained in both cases. Finally, we discuss the issues that should be taken into consideration when designing a parallel planning system and relate our work to the existing literature.
Studia Logica, 2005
In this paper, we discuss the weakness of current action languages for sensing actions with respe... more In this paper, we discuss the weakness of current action languages for sensing actions with respect to modeling domains with multi-valued fluents. To address this problem, we propose a language with sensing actions and multi-valued fluents, called AMK , provide a transition function based semantics for the language, and demonstrate its use through several examples from the literature. We then define the entailment relationship between action theories and queries in AM K , denoted by |= AM K , and discuss some properties about AMK .
IEEE Transactions on Knowledge and Data Engineering, 2012
Information extraction systems are traditionally implemented as a pipeline of special-purpose pro... more Information extraction systems are traditionally implemented as a pipeline of special-purpose processing modules targeting the extraction of a particular kind of information. A major drawback of such an approach is that whenever a new extraction goal emerges or a module is improved, extraction has to be reapplied from scratch to the entire text corpus even though only a small part of the corpus might be affected. In this paper, we describe a novel approach for information extraction in which extraction needs are expressed in the form of database queries, which are evaluated and optimized by database systems. Using database queries for information extraction enables generic extraction and minimizes reprocessing of data by performing incremental extraction to identify which part of the data is affected by the change of components or goals. Furthermore, our approach provides automated query generation components so that casual users do not have to learn the query language in order to perform extraction. To demonstrate the feasibility of our incremental extraction approach, we performed experiments to highlight two important aspects of an information extraction system: efficiency and quality of extraction results. Our experiments show that in the event of deployment of a new module, our incremental extraction approach reduces the processing time by 89.64 percent as compared to a traditional pipeline approach. By applying our methods to a corpus of 17 million biomedical abstracts, our experiments show that the query performance is efficient for real-time applications. Our experiments also revealed that our approach achieves high quality extraction results.
Entrepreneurship Theory and Practice, 2010
This article investigates whether bribery in emerging economies matters and whether such bribery ... more This article investigates whether bribery in emerging economies matters and whether such bribery has a diminishing return to performance. Bribery allows entrepreneurs to develop and foster a network of informal relationships with public officials, and reap the accompanying benefits; but it may also have disadvantages, such as an inefficient allocation of resources. The relationship between bribery and performance was estimated using unique data derived from a survey of 606 Vietnamese entrepreneurs. We controlled for various entrepreneurial, organizational, and industrial characteristics. The exploratory results provide support for a hill–shaped non–monotonic relationship between bribery and revenues.
Proceedings of the 20th international joint …, 2007
In this paper we extend the logic programming based conformant planner described in [Son et al., ... more In this paper we extend the logic programming based conformant planner described in [Son et al., 2005a] to allow it to work on planning problems with more complex descriptions of the initial states. We also compare the extended planner with other ...
Artificial Intelligence, 2011
This paper describes our methodology for building conformant planners, which is based on recent a... more This paper describes our methodology for building conformant planners, which is based on recent advances in the theory of action and change and answer set programming. The development of a planner for a given dynamic domain starts with encoding the knowledge about fluents and actions of the domain as an action theory D of some action language. Our choice in this paper is AL-an action language with dynamic and static causal laws and executability conditions. An action theory D of AL defines a transition diagram T (D) containing all the possible trajectories of the domain. A transition s, a, s belongs to T (D) iff the execution of the action a in the state s may move the domain to the state s. The second step in the planner development consists in finding a deterministic transition diagram T lp (D) such that nodes of T lp (D) are partial states of D, its arcs are labeled by actions, and a path in T lp (D) from an initial partial state δ 0 to a partial state satisfying the goal δ f corresponds to a conformant plan for δ 0 and δ f in T (D). The transition diagram T lp (D) is called an 'approximation' of T (D). We claim that a concise description of an approximation of T (D) can often be given by a logic program π(D) under the answer sets semantics. Moreover, complex initial situations and constraints on plans can be also expressed by logic programming rules and included in π(D). If this is possible then the problem of finding a parallel or sequential conformant plan can be reduced to computing answer sets of π(D). This can be done by general purpose answer set solvers. If plans are sequential and long then this method can be too time consuming. In this case, π(D) is used as a specification for a procedural graph searching conformant planning algorithm. The paper illustrates this methodology by building several conformant planners which work for domains with complex relationship between the fluents. The efficiency of the planners is experimentally Preprint submitted to Elsevier Science evaluated on a number of new and old benchmarks. In addition we show that for a subclass of action theories of AL our planners are complete, i.e., if in T lp (D) we cannot get from δ 0 to a state satisfying the goal δ f then there is no conformant plan for δ 0 and δ f in T (D).
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Papers by Phan Thi Cam Tu B1911431