Resource Information Retrieval Using SENS - A Scalable and Expressive Naming System

We design a scalable and expressive naming system called SENS, which can retrieve information of computing and content resourcesdistributed widely on the Internet by exact queries and multi-attributerange queries over resource names. Our system utilizes a descriptive nam-ing scheme to name resources and a multi-dimensional resour ce ID spacefor message routing through the overlay network of name servers (NSs). The resource ID space is constructed on the overlay network based on CAN routing algorithm. We propose a novel mapping scheme between resource names and resource IDs, which can preserve the locality of resource IDs while still achieving a good degree of load balancing regarding resource information distribution. We also propose a multicast routing algorithm todeliver resource information and a broadcast routing algorithm to routequery messages to corresponding NSs at small cost. Our simulation re-sults show that our system can achieve good routing performance and loadbalancing.
http://repository.vnu.edu.vn/handle/VNU_123/14457

Verifying Specifications with Proof Scores in CafeOBJ

Verifying specifications is still one of the most important undeveloped reseach topics in software engineering. It is important because quite a few critical bugs are caused at the level of domains, requirements, and/or designs. It is also important for the cases where no program codes are generated and specifications are analyzed and verified only for justifying models of problems in real world. Formal methods is not the “silver bullet”, but is still expected to improve the practice of constructions/analyses/verifications of domain/requirement/design speci- fications.
http://repository.vnu.edu.vn/handle/VNU_123/14458

UML design verification based on model checking techniques

The advance of embedded computing technologies makes our society increasingly depend on these systems, and the reliability of the systems becomes more and more important for our daily life. Against this background, we have been examining the application of model checking techniques to embedded software design verification, and also developing a tool to support UML design verification. In my talk, I will explain our approach and tool, then emphasize the necessity of developing modeling techniques for design verification.

http://repository.vnu.edu.vn/handle/VNU_123/14460

Degradation of diferent types of polyethylene using for lining system exposed to hydro chloride acid solution

This paper focuses on degradation behavior of a maleic anhydride modified and another new modified polyethylene used for lining system as anti-corrosion agent when exposed to hydrochloric acid solution environment. Different concentrations of HCl solution ： 0, 10, and 20 mass％at temperatures of 40, 60, and 80°C were set to investigate the degradation behavior of the two types of modified polyethylene. Virgin PE was also subjected to the same conditions for comparison. Weight change, chloride element penetration, and changes in chemical structure were measured. The immersion test result showed that the diffusion of water and the HCl solution into the neat PE obeyed Fickian diffusion model while those into both modified PE obeyed Fickian mode at low temperatures only. Two-saturation stages were observed for the samples immersed in HCl solutions at 80°C . The modified PE samples were degraded bythe HCl solutions while there was no change of chemical structure for the case of the PE resin. The high temperatureenhanced the order of degradation. IR spectra showed structural changes, which maybe attributed to the modifiercomponents in the polymers.
http://repository.vnu.edu.vn/handle/VNU_123/14461

Diffusion behaviour of corrosive solution environments in carbon black filled modified polyethylene linings

The diffusion behaviour of water and HCl solution at different temperatures and concentrations into a modified polyethylene filled with carbon black used for lining is presented. It has shown the predominant role of nature of environment and carbon black content. In the both environments, an increase of environmental temperature increased the capacity of environmental absorption and the diffusion rate. The lower sorption capacity was observed at 40 and 60 o C while a higher at 80o C in the water. The two-stage diffusion appeared for the case of the corrosive environment at 80o C. An increase of carbon black loading was increased both diffusion rate and saturation values. Diffusion of the environment into the polymer proposed by the following: environmental molecules diffusing into the polymer matrix through porous system, were trapped by functional groups on the carbon black surface and polymer molecule chain, and are immobilized. This explains the increase of sorption capacity when increase carbon black loading.
http://repository.vnu.edu.vn/handle/VNU_123/14462

Accelerated Parallel Magnetic Resonance Imaging with Multi-Channel Chaotic Compressed Sensing

Fast acquisition in magnetic resonance imaging (MRI) is considered in this paper. Often, fast acquisition is achieved using parallel imaging (pMRI) techniques. It has been shown recently that the combination of pMRI and compressed sensing (CS), which enables exact reconstruction of sparse or compressible signals from a small number of random measure- ments, can accelerate the speed of MRI acquisition because the number of measurements are much smaller than that by pMRI per se. Also recently in CS, chaos filters were designed to obtain chaotic measurements. This chaotic CS approach potentially offers simpler hardware implementation. In this paper, we combine chaotic CS and pMRI. However, instead of using chaos filters, the measurements are obtained by chaotically undersampling the k -space. MRI image reconstruction is then performed by using nonlinear conjugate gradient optimization. For pMRI, we use the well-known approach SENSE – sensitivity encoding –, which requires an estimation of the sensitivity maps. The performance of the proposed method is analyzed using the point spread function, the transform point spread function, and the reconstruction error measure.
http://repository.vnu.edu.vn/handle/VNU_123/14442

Toward an Adaptive Learning System Framework: Using Bayesian Network to Manage Learner Model

This paper represents a new approach to manage learner modeling in an adaptive learning system framework. It considers developing the basi c components of an adaptive learning system such as the learner model, the course content model and the adaptation engine. We use the overlay model and Bayesian network to evaluate learners’ knowledge. In addition, we also propose a new content modeling method as well as adap tation engine to generate adaptive course based on lear ner’s knowledge. Based on this approach, we developed an adaptive learning system named is ACGS-II, that teaches students how to design an Entity Relationship model in a database system course. Empirical testing results for students who used the application indicate that our proposed model is very helpful as guidelines to develop adaptive learning system to meet learners’ demands.
http://repository.vnu.edu.vn/handle/VNU_123/14444

Bayesian Network to Manage Learner Model in Context-Aware Adaptive System in Mobile Learning

Ubiquitous learning is of interest to many researchers and developers to build adaptive course for learners at anytime and in anywhere. To create personalized learning content suitable for each learner, one challenge is to manage and ev aluate the learning model, known as the learner's profile. Our previous study represented a model of CAMLES [1] system which is a personalized context – aware adaptive system in mobile learning to support students to learn English as a foreign language in order to prepare for the TOEFL test as a case study in Vietnam. This paper represents how to apply Bayesian Network in order to manage learner model which is a key factor to determine the learning content adaptation for the learner’s demands and knowledge of individual learners. Uncertainty factors used to determine the level of understanding of learners for each concept in the content mode
http://repository.vnu.edu.vn/handle/VNU_123/14445

Preparedness Assessment for the Integration of Sustainability Criteria in the Public Procurement of Infrastructure in Vietnam

In line with the country's current examination of "Green Growth", it is needed to conducting a policy research in the field of public procurement, to examine how Viet Nam's legal and policy framework for environmental protection may be optimized to allow for the successful introduction of green procurement. To support this process, this research aims to explore the prevailing framework for Public Procurement of infrastructure and to make recommendations on how it can be greened. A lack of efficient infrastructure is currently listed by many investors as the number one problem when operating in Vietnam, and can potentially slow down Vietnam's growth. As investment efficiency will have to increase to maintain rapid growth, it is both an opportunity and necessity to include sustainability standards in new or adjusted institutional frameworks and legislation. This paper presents the result of a joint research between the Institute of Strategy and Policy on Natural Resources and Environment (ISPONRE), Ministry of Natural Resources and Environment of Vietnam (MONRE), and the International Institute for Sustainable Development (IISD), Canada. The two institutes carried out a feasibility study and preparedness assessment of Sustainable Public Procurement (SPP) of infrastructure in Vietnam. It analyzed the legal and institutional framework of traditional public procurement and public-private partnerships for the procurement of infrastructure, as well as the hurdles and opportunities for integrating sustainability criteria in both methods of public procurement in the future. At the same time, the study paid specific attention to market readiness in order to make sound and implementable sustainable development policy recommendations that are inclusive of both environmental concerns and socio-economic development of Vietnam.
http://repository.vnu.edu.vn/handle/VNU_123/14211

Environmental Management System for Small- and Medium-sized Enterprises

1. Develop and provide socially beneficial and safe goods and services that give satisfaction to consumers and customers. 2. Engage in fair, transparent and free competition and ensure that transactions are appropriate. Also, maintain a sound and proper relationship with political bodies and government agencies. 3. In addition to communicating with shareholders, interact extensively with the public, and disclose corporate information actively and fairly. Also, protect and properly manage personal and customer data and other types of information. 4. Respect diversity, character and personality of employees and ensure a safe and comfortable working environment, thereby providing a sense of comfort and richness. 5. Proactively initiate measures in acknowledgment of environmental issues, the common challenges they pose to humanity and their importance to its existence and livelihood. 5.1 Promote efforts to build a low-carbon society on a global scale. 5.2 Promote efforts to build a material-cycle society. 5.3 Take measures against environmental risks. 5.4 Promote efforts to conserve biodiversity and sustainable utilization of resources. 6. Actively engage in community involvement activities including philanthropy as a "good corporate citizen." 7. Resolutely confront antisocial forces and organizations that pose a threat to the order and security of civil society and sever all relations with such individuals and groups.
http://repository.vnu.edu.vn/handle/VNU_123/14212