Does Agglomeration Account for Process Innovation in Vietnamese Small and Medium Enterprises?

Although small and medium enterprises (SMEs) play a crucial role in the Vietnamese economy, this sector’s growth is hindered by low level of technology and innovation. This paper uses firm-level panel data to examine whether process innovation activities in SMEs are influenced by their industrial environments. It measures the effects that agglomeration, the geographic concentration of firms within the same locality, has on firms’ total outputs and their propensity to introduce new technology. Using a logistic model with firm fixed-effects, I find that agglomeration decreases outputs of informal firms and the likelihood of new technology introduction in all firms. However, there are evidence of positive lagged effects of agglomeration on innovation and heterogeneous effects across industries

Analysis of LTE-A Heterogeneous Networks with SIR-based Cell Association and Stochastic Geometry

This paper provides an analytical framework to characterize the performance of Heterogeneous Networks (HetNets), where the positions of base stations and users are modeled by spatial Poisson Point Processes (stochastic geometry). We have been able to formally derive outage probability, rate coverage probability, and mean user bit-rate when a frequency reuse of $K$ and a novel prioritized SIR-based cell association scheme are applied. A simulation approach has been adopted in order to validate our analytical model; theoretical results are in good agreement with simulation ones. The results obtained highlight that the adopted cell association technique allows very low outage probability and the fulfillment of certain bit-rate requirements by means of adequate selection of reuse factor and micro cell density. This analytical model can be adopted by network operators to gain insights on cell planning. Finally, the performance of our SIR-based cell association scheme has been validated through comparisons with other schemes in literature.Comment: Paper accepted to appear on the Journal of Communication Networks (accepted on November 28, 2017); 15 page

On the existence and exponential attractivity of a unique positive almost periodic solution to an impulsive hematopoiesis model with delays

In this paper, a generalized model of hematopoiesis with delays and impulses is considered. By employing the contraction mapping principle and a novel type of impulsive delay inequality, we prove the existence of a unique positive almost periodic solution of the model. It is also proved that, under the proposed conditions in this paper, the unique positive almost periodic solution is globally exponentially attractive. A numerical example is given to illustrate the effectiveness of the obtained results.Comment: Accepted for publication in AM

The Development of a Novel Polymer Based System for Gene Delivery

Gene therapy involves the use of nucleic acids, either DNA or RNA for the treatment, cure, or prevention of human diseases. Synthetic cationic polymers are promising as a tool for gene delivery because of their high level of design flexibility for biomaterial construction and are capable of binding and condensing DNA through electrostatic interactions. Our lab has developed a novel polymer (poly (polyethylene glycol-dodecanoate) (PEGD), a polyester of polyethylene glycol (PEG) and dodecanedioic acid (DDA). PEGD is a linear viscous polymer that self-assembles into a vesicle upon immersion in an aqueous solution. A copolymer of dodecanedioc acid and polyethylene glycol (PEG) was synthesized at a 1:1 ratio. Furmaric (FA) or itaconic acid (IA) was used to suppress DDA in the PEGD copolymer at an 80:20 ratio (DDA: furmaric/itaconic acid) to form the PEGDF/I variant. PEGDF/I are then modified through the Michael addition of Protamine Sulfate (PEGDF/I-PS) and Cys-Arg8 (PEGDF/I-CA) peptide to the carbon-carbon double bond on the polymer backbone to introduce a positive charge. The modified PEGDF/I polymers were capable of binding and condensing DNA. Transfection of HEK 293 cells with pTurboGFP plasmid using modified PEGDF/I polymers was successful but showed varied efficiency. The PEGDF/I-CA polymer had around 30% transfection efficiency and was shown to be non-cytotoxic

Soviet Legacy of Vietnam's Intellectual Property Law: Big Brother is (No Longer) Watching You

How did intellectual property (IP), a private right born out of European Enlightenment ideals, take root in Vietnam's socialist legal framework, and what influence does Vietnam's Soviet legacy still have on its IP law? The clandestine triumph of IP rights in Vietnam is remarkable, given the system's former propensity for collective ownership and limited private property rights. Vietnam's approach to IP rights has changed with economic liberalisation: while external pressure prompted the initial adoption of IP laws, national interest and global reputation enhancement are now driving the effort. At the height of communism in the 1980s and under Soviet domination, IP laws reflected socialist ideology and the characteristics of a command economy. Amid Vietnam's quest for technological advancement, the importance of patents has grown. However, public perceptions of the unreliability of the legal system to resolve IP disputes persist, pushing civil disputes towards the government rather than the judiciary. As Vietnam opened economically, its IP regime moved away from overt communism, but communist values are still implicitly incorporated in general principles. Today, adherence to free trade agreements, which require robust IP protection, is driving the modernisation of Vietnam's IP infrastructure

Some new analytical results for plastic buckling and initial post-buckling of plates and cylinders under uniform compression

International audienceThis paper is devoted to the theoretical aspects of the elastoplastic buckling and initial post-buckling of plates and cylinders under uniform compression. The analysis is based oil the 3D plastic bifurcation theory assuming the J(2) flow theory of plasticity with the von Mises yield criterion and a linear isotropic hardening. The proposed method is shown to be a systematic and unified way to obtain the critical loads, the buckling modes and the initial slope of the bifurcated branch for rectangular plates under uniaxial or biaxial compression(-tension) and cylinders under axial compression, with various boundary conditions