124 research outputs found
The emerging legal framework for private sector development in Viet Nam's transitional economy
A major objective of Viet Nam's transition to a market economy has been to reactivate the private sector in a mixed economy. Several new laws have been introduced in the past five years to implement this policy and to create an enabling environment for the private sector. The author reviews some of the more important laws and regulations that affect Viet Nam's private sector activities, including laws on real property, intellectual property, companies, domestic investment, foreign investment, bankruptcy, contracts, and dispute resolution. Anti-monopoly law has not yet been introduced in Viet Nam. The issue of competition is addressed in the context of trade law, the relative roles of the state and private sector, and restrictions in company law. These areas all establish the foundation of a legal framework for a market economy. The author concludes that Viet Nam's legal framework, like China's, is still influenced by ideology, which causes problems in such areas as private ownership of real property and with such fundamental legal concepts as"due process of law."It is noted that the private sector is constrained by the lack of an independent judiciary, the absence of private land ownership, other uncertainties in property law that limit the develpoment of financial markets, and the inherent bias of the system in favor of the state sector (and collective ownership). Also noted is a law-abiding attitude, equally important to development has been slow to develop. The author goes on to point out that the foreign investment process is too complicated, and its company law too restrictive. A first priority should be to strreamline regulations, as well as liberalize trade policy and increase efforts in privatization of state enterprises. In this respect the author notes that export processing zones may be a useful interim instrument to attract foreign investment but should be phased out over time. More important in the long term is a good investment climate resting on a strong legal foundation.Legal Products,Environmental Economics&Policies,Banks&Banking Reform,Municipal Housing and Land,Municipal Financial Management,Environmental Economics&Policies,Banks&Banking Reform,Municipal Housing and Land,Legal Products,Municipal Financial Management
SOME PROPERTIES OF EF-EXTENDING RINGS
In [16], Thuyet and Wisbauer considered the extending property for the class of (essentially) finitely generated submodules. A module M is called ef-extending if every closed submodule which contains essentially a finitely generated submodule is a direct summand of M. A ring R is called right ef-extending if RR is an ef-extending module. We show that a ring R is right ef-extending and the R-dual of every simple left R-module is simple if and only if R is semiperfect right continuous with Sl = Sl ≤e RR. We also prove that a ring R is a QF-ring if and only if R is left Kasch and RR(ω)
is ef-extending if and only if R is right AGP-injective satisfying DCC on right (or left) annihilators and (R ⊕ R)R is ef-extending.</p
The Microstructural Revolution of Ti-6Al-4V Specimens Fabricated by Selective Laser Sintering of Pre-alloyed Powders
Selective laser sintering (SLS) is known as a cutting-edge technique to manufacture complex geometry products. Among various kinds of materials, Ti-6Al-4V is one of the most popular materials for the SLS process. The as-built Ti-6Al-4V products were widely applied in many applications such as aerospace, automobile, and especially in medical and implant parts. The purpose of this research is to investigate the microstructure and other properties of Ti6Al4V pre-alloyed powders produced by selective laser sintering technique. Through this research, the direct fabrication of Ti6Al4V metal object by SLS machine has been carried out using MetalSys250 machine. Different parameters of the SLS process were used to produce 1cm x1cmx1cm cubic samples and then microstructure, as well as mechanical properties of the as-built samples were investigated. Powder particles are fully dense, possess a spherical shape and are composed of acicular α phase. The as-build sample shows the oriented acicular martensitic phase with the defined columnar grain structures
Investigating Lateral Displacement of Pile Groups under Construction Loads and Excavation—A Case Study
Piles in weak soils are sensitive to adjacent excavation and construction loads. Excessive lateral displacement of piles during construction adds shear and bending moment to the piles. This is of great concern because these additional lateral loads are sometimes not accounted for when designing piles, and the horizontal bearing capacity as well as shear strength of the piles is low. This paper presents a case study of a recent project with severe pile damage and large soil displacement during construction due to the installation of adjacent piles and excavating foundation pits. With improper construction procedures, the piles were severely damaged and have almost no bearing capacity before the construction of the superstructure even begins. On-site measured data were used as inputs for numerical simulations, and analyses were carried out to study the behaviors of pile groups affected by construction activities. The simulation was for each construction activity/stage as well as the whole construction process to determine the effects of excavation and deep foundation construction equipment loadings used for pile installation. The effects on the lateral displacement of piles and surrounding soil were quantified. The results from finite element analysis on the lateral deformation of piles are in good agreement with the measured data, with differences of about 5%–10%. Several construction procedures are recommended, with recommendations made to mitigate pile damages and large soil displacement due to construction. With the recommended procedures, the lateral deformation of pile groups can be greatly reduced by at least 90% and pile damages can be eliminated
PERFORMANCE OF A BASE-ISOLATED RC BUILDING SUPPORTED ON SQUARE UN-BONDED FIBER REINFORCED ELASTOMERIC ISOLATOR UNDER EARTHQUAKES
Un-bonded fiber reinforced elastomeric isolator (U-FREI) is a relatively new type of multi-layer elastomeric isolator in which fiber layers are used as reinforcement to replace steel sheets in conventional steel reinforced elastomeric isolators. It is installed directly between the substructure and superstructure without any connection at the interfaces. Most of the previous studies on the U-FREIs supported to the base-isolated buildings are masonry or stone structures. In this study, the dynamic responses of a reinforced concrete (RC) building supported on square U-FREIs under the action of recorded real time-history ground motions of earthquakes are investigated by finite element analysis using SAP2000 software. A hypothetical 4-storey reinforced concrete building constructed in Vietnam is selected for the study. Comparison of the dynamic responses of the base-isolated building and corresponding fixed-base building is carried out to evaluate the seismic vulnerability of the base-isolated building under earthquakes. Finite element analysis results show that peak values of floor acceleration and inter-storey drifts at different floor levels, and peak value of base shear of the base-isolated building are lower than those of the corresponding fixed-base building. The U-FREIs are found to be very effective in reducing seismic vulnerability of low and mid-rise RC buildings
Predicting Tensile Strength for Prestressed Reinforced Concrete-Driven Piles
Reinforced concrete piles installed by impact hammers have been used as a common solution for deep foundations because they are cost effective and require less time for construction. Driven piles are often used in large volumes for infrastructure and industrial projects in rural areas. Unlike other installation methods, installing piles using impact hammers can generate tensile stress during construction, which can result in pile failures. Induced tensile stress occurs when piles are being driven through a hard soil layer to a softer soil layer, and transverse cracks happen when induced tensile stress exceeds the pile tensile strength. This issue is not explicitly stated in most standards; the rare code that mentions this issue is AASHTO 2014. AASHTO 2014 uses correlations between the concrete tensile and compressive strengths to obtain the pile tensile strength. However, data collected from more than 1300 tests on the correlations between the concrete tensile and compressive strengths show that the concrete pile tensile strengths obtained using AASHTO 2014 are significantly conservative. This paper provides an adjustment in the correlation for the tensile strength based on previous data, and it proposes an approach to estimate the tensile strength for concrete-driven piles. A case study of the effects of pile failures on the tensile strength is also presented to verify the approach. The obtained tensile strength from the proposed approach agrees well with the measured field data. For the case study, the pile tensile strength obtained using the proposed approach is 38% and 59% higher than the tensile strength obtained using AASHTO 2014. These quantities are significant but may vary, depending on the compression strength of the concrete used and the pile configurations. The proposed approach better predicts the tensile strength of concrete piles and can lead to cost savings. View Full-Tex
Linear Approximation and Asymptotic Expansion of Solutions for a Nonlinear Carrier Wave Equation in an Annular Membrane with Robin-Dirichlet Conditions
This paper is devoted to the study of a nonlinear Carrier wave equation in an annular membrane associated with Robin-Dirichlet conditions. Existence and uniqueness of a weak solution are proved by using the linearization method for nonlinear terms combined with the Faedo-Galerkin method and the weak compact method. Furthermore, an asymptotic expansion of a weak solution of high order in a small parameter is established
MÔĐUN BẤT BIẾN ĐẲNG CẤU TRÊN VÀNH GOLDIE PHẢI
In this paper, we study some properties of automorphism invariant modules on the right Goldie ring and state some properties related to this class of modules. In addition, we confirmed some problems related to the nonsingular automorphism invariant ring.Trong bài báo này, chúng tôi nghiên cứu một số kết quả về môđun bất biến đẳng cấu trên vành Goldie phải, đồng thời nêu một số tính chất liên quan đến lớp các môđun này. Ngoài ra, chúng tôi cũng khẳng định một số vấn đề liên quan đến lớp vành bất biến đẳng cấu không suy biến
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