Is Vietnam economic paradigm sustainable for catch up

In the course of catching-up, Vietnam faces risks in two sectors: in real sector and in financial sector. In this paper we focus mostly on risk in real sector: the risk of getting stuck in middle-income trap. Vietnam is still far lagged behind her neighbors and much more further to developed economies. Does the economic paradigm that Vietnam follows in the last two decades allow her to catch up with those economies? We show that Vietnam’s economic growth in the last two decades based essentially on cheap but low skill labor and physical capital. Participation in international and regional production network probably lock Vietnam in low-tech position, hence low value added. If Vietnam keeps on growing in present paradigm, hardly can it catch up the neighboring economies.Flying geese paradigm, VAR models, TFP, Technological improvement, catch-up, Vietnam.

Optimization in microgrid design and energy management

The dissertation is composed of three papers, which cover microgrid systems performance characterization, optimal sizing for energy storage system and stochastic optimization of microgrid operation. In the first paper, a complete Photovoltaic-Vanadium Redox Battery (VRB) microgrid is characterized holistically. The analysis is based on a prototype system installation deployed at Fort Leonard Wood, Missouri, USA. In the second paper, the optimal sizing of power and energy ratings for a VRB system in isolated and grid-connected microgrids is proposed. An analytical method is developed to solve the problem based on a per-day cost model in which the operating cost is obtained from optimal scheduling. The charge, discharge efficiencies, and operating characteristics of the VRB are considered in the problem. In the third paper, a novel battery operation cost model is proposed accounting for charge/discharge efficiencies as well as life cycles of the batteries. A probabilistic constrained approach is proposed to incorporate the uncertainties of renewable sources and load demands in microgrids into the UC and ED problems --Abstract, page iv

Institutional Changes for Private Sector Development in Vietnam : Experience and Lessons

Vietnam, Centrally Planned Economies, Transition, reform, institutions

Generating Natural Language Explanations For Entailments In Ontologies

Building an error-free and high-quality ontology in OWL (Web Ontology Language)---the latest standard ontology language endorsed by the World Wide Web Consortium---is not an easy task for domain experts, who usually have limited knowledge of OWL and logic. One sign of an erroneous ontology is the occurrence of undesired inferences (or entailments), often caused by interactions among (apparently innocuous) axioms within the ontology. This suggests the need for a tool that allows developers to inspect why such an entailment follows from the ontology in order to debug and repair it. This thesis aims to address the above problem by advancing knowledge and techniques in generating explanations for entailments in OWL ontologies. We build on earlier work on identifying minimal subsets of the ontology from which an entailment can be drawn---known technically as justifications. Our main focus is on planning (at a logical level) an explanation that links a justification (premises) to its entailment (conclusion); we also consider how best to express the explanation in English. Among other innovations, we propose a method for assessing the understandability of explanations, so that the easiest can be selected from a set of alternatives. Our findings make a theoretical contribution to Natural Language Generation and Knowledge Representation. They could also play a practical role in improving the explanation facilities in ontology development tools, considering especially the requirements of users who are not expert in OWL

Rice cultivation and soil properties as affected by Alternative Wetting and Drying irrigation in Chau Thanh, An Giang province

The study that was carried out in winter-spring 2018 in Thoai Son, An Giang province, include experiments: Effects of (AWDI) to (i) Characters in soil; (ii) rice yield and (iii) water use and water use efficiency of Jasmine rice. The experiment was carried out with 4 treatments, 4 replications. The treatments ranged from continuous submergence (NT1) of the field to a number of delayed irrigations (NT2, NT3, NT4) denoting application of 4 cm irrigation water when water level in the perforated PVC pipe fell 18, 14 and 10 cm below ground level. The study revealed that NT1 attributed by the highest total water use (118 cm) and the lowest WUE (60.3 kg/ha/cm) produced the highest grain yield (8,10 t/ha). On the contrary, the yields in NT3 (6.80 t/ha) and NT2 (5.80 t/ha) were significantly lower at 0,5 times level of significance compared to that of NT1 and NT4 (7.83 t/ha)

With exhaustible resources, can a developing country escape from the poverty trap ?

This paper studies the optimal growth of a developing non-renewable natural resource producer, which extracts the resource from its soil and produces a single consumption good with man-made capital. Moreover, it can sell the extracted resource abroad and use the revenues to buy an imported good, which is a perfect substitute of the domestic consumption good. The domestic technology is convex-concave, so that the economy may be locked into a poverty trap. We study the optimal extraction and depletion of the exhaustible resource and the optimal paths of accumulation of capital and of domestic consumption. We show that the extent to which the country will optimally escape from the poverty trap and the exhaustible resource will be a blessing depends on the characteristics of its technology and of the revenues from the resource function, on its impatience, on the level of its initial stock of capital and on the abundance of the natural resource. If the marginal productivity of capital at the origin is greater than the sum of the social discount rate and the depreciation rate, the country will accumulate capital along the entire growth path and will escape from the poverty trap, whatever its initial stocks of capital and resource, and provided that the marginal revenue obtained from the exportation of the resource is finite at the origin. On the contrary, if the marginal productivity of capital is lower than the depreciation rate whatever the level of capital and if moreover the initial stock of capital is small, then the country will never accumulate ; it will consume the revenues obtained from selling abroad the extracted resource, until there is no resource left and the economy collapses. We also show that any optimal path may be decentralized in a competitive equilibrium by using a tax/subsidy scheme for firms.Optimal growth, exhaustible resource, convex-concave technology, poverty trap, competitive equilibrium with tax/subsidy.

With Exhaustible Resources, Can A Developing Country Escape From The Poverty Trap?

This paper studies the optimal growth of a developing non-renewable natural resource producer. It extracts the resource from its soil, and produces a single consumption good with man-made capital. More- over, it can sell the extracted resource abroad and use the revenues to buy an imported good, which is a perfect substitute of the domes- tic consumption good. The domestic technology is convex-concave, so that the economy may be locked into a poverty trap. We show that the extent to which the country will escape from the poverty trap depends, besides the interactions between its technology and its impatience, on the characteristics of the resource revenue function, on the level of its initial stock of capital, and on the abundance of the natural resource.optimal growth;non-renewable resource;convex-concave technology;poverty trap;resource curse

Neural Network Verification as Piecewise Linear Optimization: Formulations for the Composition of Staircase Functions

We present a technique for neural network verification using mixed-integer programming (MIP) formulations. We derive a \emph{strong formulation} for each neuron in a network using piecewise linear activation functions. Additionally, as in general, these formulations may require an exponential number of inequalities, we also derive a separation procedure that runs in super-linear time in the input dimension. We first introduce and develop our technique on the class of \emph{staircase} functions, which generalizes the ReLU, binarized, and quantized activation functions. We then use results for staircase activation functions to obtain a separation method for general piecewise linear activation functions. Empirically, using our strong formulation and separation technique, we can reduce the computational time in exact verification settings based on MIP and improve the false negative rate for inexact verifiers relying on the relaxation of the MIP formulation