THE QUALITY WATER ENVIRONMENT HAPPENING OF THE HUONG RIVER IN THE HUE CITY, PERIOD OF 2003-2006

Joint Research on Environmental Science and Technology for the Eart

New Technology, Human Capital and Growth in a Developing Country

In a developing country with three sectors: consumption goods, new tech- nology, and education, the productivity of the consumption goods depends on a new technology and skilled labor used to produce this new technology. There can be three stages of economic growth. In the …rst stage the country concentrates on the production of consumption goods; in the second the country must import both physical capital and new technology capital to produce consumption goods and new technology; in the third the country must import capital and invest in the training and education of high skilled labor.Optimal growth model; New technology capital;Human Capital; Developing country

New Technology, Human Capital and Growth for European Transitional Economies.

We consider a transitional country with three sectors in economy: con- sumption goods, new technology, and education. Productivity of the con- sumption goods sector depends on new technology and skilled labor used for production of the new technology. Then there might be three stages of economic growth. In the first stage the country concentrates on produc- tion of consumption goods; in the second stage the country imports both physical capital and new technology capital; in the last stage the country imports new technology capital and invests in training and education of high skilled labor in the same time.Optimal growth model, New technology capital, Human Capital, Developing country.

THE CONSUMER TRENDS OF SECONDHAND CLOTHING IN YOUNG PEOPLE – THE CASE OF THE GENERATION Z OF VIETNAM

In recent years, secondhand clothes have become a fashion trend that is enthusiastically supported by Vietnamese youth thanks to their fashionability and environmental friendliness. A series of second-hand shops, warehouses, and consignment events have sprung up in parallel with second-hand markets that have existed for many years, still attracting many visitors. In order to examine the trend of secondhand clothing consumption among young Vietnamese, the research team conducted this study. Through the results of the study, it can be seen that the main personal factors leading to the use of secondhand clothes by the survey subjects are spending savings and personal preferences. Most of the decisions to buy secondhand clothes are influenced by the uniqueness of the product and by friends and relatives. The most enabling aspect when using secondhand clothes is the product quality and the product's design, while the aspects that are the most concerns by both users and non-users of secondhand clothes are a matter of hygiene and health

Creating Fatigue Curve for Steel Machine Elements Using Fatigue Test Method with Gradually Increasing Stress Amplitude

In order to create a fatigue curve, the traditional fatigue test method is applied to specimens using a cyclic stress with constant amplitude. However, this method has disadvantages such as the experimental results could not be used because of specimens broken before reaching the expected stress amplitude, or the tests may be stopped before specimen broken because of limitation of time. To overcome this hurdle of the traditional method, a new experimental method using cyclic stress with gradually increasing amplitude was proposed to build the fatigue curve for steel machine elements

On the Discovery of Semantically Meaningful SQL Constraints from Armstrong Samples: Foundations, Implementation, and Evaluation

A database is said to be C-Armstrong for a finite set Σ of data dependencies in a class C if the database satisfies all data dependencies in Σ and violates all data dependencies in C that are not implied by Σ. Therefore, Armstrong databases are concise, user-friendly representations of abstract data dependencies that can be used to judge, justify, convey, and test the understanding of database design choices. Indeed, an Armstrong database satisfies exactly those data dependencies that are considered meaningful by the current design choice Σ. Structural and computational properties of Armstrong databases have been deeply investigated in Codd’s Turing Award winning relational model of data. Armstrong databases have been incorporated in approaches towards relational database design. They have also been found useful for the elicitation of requirements, the semantic sampling of existing databases, and the specification of schema mappings. This research establishes a toolbox of Armstrong databases for SQL data. This is challenging as SQL data can contain null marker occurrences in columns declared NULL, and may contain duplicate rows. Thus, the existing theory of Armstrong databases only applies to idealized instances of SQL data, that is, instances without null marker occurrences and without duplicate rows. For the thesis, two popular interpretations of null markers are considered: the no information interpretation used in SQL, and the exists but unknown interpretation by Codd. Furthermore, the study is limited to the popular class C of functional dependencies. However, the presence of duplicate rows means that the class of uniqueness constraints is no longer subsumed by the class of functional dependencies, in contrast to the relational model of data. As a first contribution a provably-correct algorithm is developed that computes Armstrong databases for an arbitrarily given finite set of uniqueness constraints and functional dependencies. This contribution is based on axiomatic, algorithmic and logical characterizations of the associated implication problem that are also established in this thesis. While the problem to decide whether a given database is Armstrong for a given set of such constraints is precisely exponential, our algorithm computes an Armstrong database with a number of rows that is at most quadratic in the number of rows of a minimum-sized Armstrong database. As a second contribution the algorithms are implemented in the form of a design tool. Users of the tool can therefore inspect Armstrong databases to analyze their current design choice Σ. Intuitively, Armstrong databases are useful for the acquisition of semantically meaningful constraints, if the users can recognize the actual meaningfulness of constraints that they incorrectly perceived as meaningless before the inspection of an Armstrong database. As a final contribution, measures are introduced that formalize the term “useful” and it is shown by some detailed experiments that Armstrong tables, as computed by the tool, are indeed useful. In summary, this research establishes a toolbox of Armstrong databases that can be applied by database designers to concisely visualize constraints on SQL data. Such support can lead to database designs that guarantee efficient data management in practice