Hong-Quang Nguyen

Computational Science and Its Applications – ICCSA 2013

The smart phone usage and multimedia devices have been increasing yearly and predictions indicate drastic increase in the upcoming years. Recently, various wireless technologies have been introduced to add flexibility to these gadgets. As data plans offered by the network service providers are expensive, users are inclined to utilize freely accessible and commonly available Wi-Fi networks indoors. LTE (Long Term Evolution) has been a topic of discussion in providing high data rates outdoors and various service providers are planning to roll out LTE networks all over the world. The objective of this presentation is to compare usefulness of these two leading wireless schemes based on LTE and Wireless Mesh Networks (WMN) and bring forward their advantages for indoor and outdoor environments. We also investigate to see if a hybrid LTE-WMN network may be feasible. Both these networks are heterogeneous in nature, employ cognitive approach and support multi hop communication. The main motivation behind this work is to utilize similarities in these networks, explore their capability of offering high data rates and generally have large coverage areas. In this work, we compare both these networks in terms of their data rates, range, cost, throughput, and power consumption. We also compare 802.11n based WMN with Femto cell in an indoor coverage scenario, while for outdoors; 802.16 based WMN is compared with LTE. The main objective is to help users select a network that could provide enhanced performance in a cost effective manner. More information can be found at http://www.iccsa.org/invited-speakers Neoclassical Growth Theory, Regions and Spatial Externalities

Computational Science and Its Applications

The smart phone usage and multimedia devices have been increasing yearly and predictions indicate drastic increase in the upcoming years. Recently, various wireless technologies have been introduced to add flexibility to these gadgets. As data plans offered by the network service providers are expensive, users are inclined to utilize freely accessible and commonly available Wi-Fi networks indoors. LTE (Long Term Evolution) has been a topic of discussion in providing high data rates outdoors and various service providers are planning to roll out LTE networks all over the world. The objective of this presentation is to compare usefulness of these two leading wireless schemes based on LTE and Wireless Mesh Networks (WMN) and bring forward their advantages for indoor and outdoor environments. We also investigate to see if a hybrid LTE-WMN network may be feasible. Both these networks are heterogeneous in nature, employ cognitive approach and support multi hop communication. The main motivation behind this work is to utilize similarities in these networks, explore their capability of offering high data rates and generally have large coverage areas. In this work, we compare both these networks in terms of their data rates, range, cost, throughput, and power consumption. We also compare 802.11n based WMN with Femto cell in an indoor coverage scenario, while for outdoors; 802.16 based WMN is compared with LTE. The main objective is to help users select a network that could provide enhanced performance in a cost effective manner. More information can be found at http://www.iccsa.org/invited-speakers Neoclassical Growth Theory, Regions and Spatial Externalities

Mining Hierarchical Negative Association Rules

Abstract The negative association between items in databases is as important and interesting as the positive one. But, it has not been studied as much. We consider negative association in a hierarchical setting, in which we are able to generate negative association rules at different hierarchy levels. It allows to impose restrictions when we proceed to the next level and discover only most interesting negative association rules among the vast number of possible negative association rules. In this paper, we propose two algorithms for mining negative association rules by considering that items are organized in a hierarchy, and this hierarchy is reflected on the association rules we produce. In this way, we can mine for both general and specialized rules of negative association between items.

GeTFIRST: ontology-based keyword search towards semantic disambiguation

– This paper aims to improve the semantic-disambiguation capability of an information-retrieval system by taking advantages of a well-crafted classification tree. The unstructured nature and sheer volume of information accessible over networks have made it drastically difficult for users to seek relevant information. Many information-retrieval methods have been developed to address this problem, and keyword-based approach is amongst the most common approach. Such an approach is often inadequate to cope with the conceptualization associated with user needs and contents. This brings about the problem of semantic ambiguation that refers to the disagreement in meaning of terms between involving parties of a communication due to polysemy, leading to increased complexity and lesser accuracy in information integration, migration, retrieval and other related activities. , – A novel ontology-based search approach, named GeTFIRST (short for Graph-embedded Tree Fostering Information Retrieval SysTem), is proposed to disambiguate keywords semantically. The contribution is twofold. First, a search strategy is proposed to prune irrelevant concepts for accuracy improvement using our Graph-embedded Tree (GeT)-based ontology. Second, a path-based ranking algorithm is proposed to incorporate and reward the content specificity. , – An empirical evaluation was performed on United States Patent And Trademark Office (USPTO) patent datasets to compare our approach with full-text patent search approaches. The results showed that GeTFIRST handled the ambiguous keywords with higher keyword-disambiguation accuracy than traditional search approaches. , – The search approach of this paper copes with the semantic ambiguation by using our proposed GeT-based ontology and a path-based ranking algorithm.

Structured content-aware discovery for improving XML data consistency

Abstract With the explosive growth of heterogeneous XML sources, data inconsistency has become a serious problem that leads to ineffective business operations and poor decision-making. To address such inconsistency, XML functional dependencies (XFDs) have been proposed to constrain the data integrity of a source. Unfortunately, existing approaches to XFDs have insufficiently addressed data inconsistency arising from both semantic and structural inconsistencies inherent in heterogeneous XML data sources. This paper proposes a novel approach, called SCAD, to discover anomalies from a given source, which is essential to address prevalent inconsistencies in XML data. Our contribution is twofold. First, we introduce a new type of path and value-based data constraint, called XML Conditional Structural Dependency (XCSD), whereby ( i ) the paths in XCSD approximately represent groups of similar paths in sources to express constraints on objects with diverse structures; while (ii) the values bound to particular elements express constraints with conditional semantics. XCSD can capture data inconsistency disregarded by XFDs. Second, our proposed SCAD is used to discover XCSDs from a given source. Our approach exploits the semantics of data structures to detect similar paths from the sources, from which a data summary is constructed as an input for the discovery process. This aims to avoid returning redundant data rules due to structural inconsistencies. During the discovery process, SCAD employs semantics hidden in the data values to discover XCSDs. To evaluate our proposed approach, experiments and case studies were conducted on synthetic datasets which contain structural diversity causing XML data inconsistency. The experimental results show that SCAD can discover more dependencies and the dependencies found convey more meaningful semantics than those of the existing XFDs.

GeTCo: an ontology-based approach for patent classification search

The main contribution of this paper is a method for creating a Graph-Embedded-Tree-based ontology, which utilizes domain knowledge from a patent classification scheme, for a patent classification process. Our contribution is twofold. First, we propose a novel definition of GeTCo ontology, which consists of four types of concept: Class, Document, Phrase, and Term. Depending on relationships of each pair of concepts, we further define their semantic information to give our classifier better reasoning capability whenever the semantic ambiguation occurs. Second, we propose a novel method to construct our ontology based on the United State Patent Classification Scheme (USPC) without relying on a rule-based method for concept extraction and thus, it can negate intensive-manual efforts in traditional ontology construction. We developed a prototype application on top of Rocchio classifier, called the GeTCo-enabled Rocchio classifier, to evaluate our proposed ontology. Our experiments with filtered 9703 single-class patents showed that the GeTCo-enabled Rocchio classifier, backed by our proposed directed-graph ontology, yields higher F1-score (i.e., +7%) than original Rocchio classifier without GeTCo supports.

MobiPDA: A Systematic Approach to Mobile-Application Development

The advent of mobile-computing platforms and profitable application-distributing channels has increasingly attracted a large number of non-professional people to mobile application development. They typically start with a simple idea about the applications of their interest; and to complete these applications, they often face two key problems: (i) the lack of a systematic method for exploring ideas and (ii) the lack of a method for organizing activities to keep balance between learning, designing and coding. Unfortunately, existing approaches have inadequately address these problems. In this paper, we propose a novel approach, named MobiPDA, to mobile application development targeting non-professional developers. Our systematic approach provides (i) conceptual tools for exploring an initial idea from different perspectives and (ii) an activities-organization process to apply these tools in software projects. We performed a comparative analysis with Mobile-D and Mobia, and evaluated MobiPDA on two pilot software projects.

MobiPSE: A scenario-based mobile-application development for end-user developers

Purpose – This paper aims to solve the stated limitations through (i) exploring usages of scenarios and (ii) proposing a lightweight iterative requirement exploration process that utilizes scenarios to transform the vague ideas of the developers into concrete application’s vision. The explosive growth in pervasiveness, programmability and computational capability of smartphones and tablets unlocks the possibility for many uses of technology, including end-user development (EUD) where end-users create applications as pragmatic tools for their work and hobbies. An extensive amount of research effort has been done to solve EUD challenges; however, the focus of such research lies mainly on designing and implementing software applications. Design/methodology/approach – Based on review on existing application of usage scenario in software application development, we proposed SRE – a scenario-based requirement exploration method and MobiPSE – a lightweight software process that applies SRE. Two EUD projects performed by undergraduate students were used as case studies to test and fine-tune methods. Findings – This paper proposes MobiPSE – a lightweight iterative software process that resolves around our proposed SRE method. Through case studies on MobiPSE, we confirmed that MobiPSE works in real-life scenarios and emphasized two points: ad hoc training has limited effect and lack of technical expertise can still leave a negative impact on requirement exploration process. Research limitations/implications – Because of the limited number of case studies performed for testing and tuning purpose, the proposed methods may not be able to satisfy all cases of EUD. MobiPSE can be fine-tuned further with additional case studies of different scale and team structure. Originality/value – This paper fulfils the need for a lightweight method for exploring requirements and ideas in a EUD project based on creating and analyzing possible usage scenarios.

SRE: A Scenario-based Requirement Exploration Process for End-user Mobile-Application Development

The world is going mobile. Explosive growth in popularity and functionality of mobile-computing allows more personal and professional tasks to be done on these portable devices, creating enormous opportunity for end-user development (EUD) -- a set of methods and techniques that allow application users to create and modify software products to support their works and hobbies. End-user developers face the same engineering challenges as professional developers, including (i) understanding their requirements, (ii) making design decisions, (iii) building application and (iv) debugging application; however, most of existing works on end-user development only focus on solving design and implementation problems. In this paper, we addressed the requirement problem of end-user developers by proposing a scenario-based iterative process for finding application requirements based on identifying different usage scenarios with the support of knowledge about background of the application topic. We evaluated our process with one comparative study and two case studies.