Development of a Web-based land evaluation system and its application to population carrying capacity assessment using .Net technology

The multi-disciplinary approach used in this study combines the state-of-the-art IT technology with an elaborated land evaluation methodology and results in a Web-based land evaluation system (WLES). The WLES is designed in such a way that the system operates both as a Web Application and as a Web Service. Implemented on top of the .NET platform, the WLES has a loosely coupled multi-layer structure which seamlessly integrates the domain knowledge of land evaluation and the soil database. The Web Service feature makes the WLES suitable to act as a building block of a larger system such as that of the population carrying capacity (PCC) assessment. As a reference application, a framework is made to assess the PCC on the basis of the production potential calculations which are available through the WLES Web Service interface

Population carrying capacity and sustainable agricultural use of land resources in Caoxian County (North China)

In this study, an attempt is made to assess the potential sustainable agricultural use of the land resources in Caoxian County in north China. Based on a land resources inventory (physiography, climate, soil, land use and management), the rotation of winter wheat-summer maize was selected as the major land utilization type of grain production in the study area. Land use requirements were adapted to the local conditions and hierarchical production potentials were estimated using the collected data. Satisfactory results have been achieved for six scenarios combining local management practices and input levels. The population carrying capacity has been obtained and guidelines for a sustainable use of land resources were formulated. Conclusions were drawn with regard to the methodologies applied

Durability and service life of concrete repairs in the presence of cracks

Engineered Cementitious Composite (ECC) has been proposed to be one of the most promising repair materials due to its unique high ductility and tight crack width control. In concrete repairs, the shrinkage of repair materials is restrained by concrete substrate, and the repair material therefore often cracks. When ECC is used as repair material, the crack width is much smaller compared to normal concrete. The tight crack width of ECC retards the penetration of water and harmful substances and thus enhances the durability of concrete repairs. This paper is aimed to explore the chloride penetration in cracked ECC repairs and to assess the service life of the repair systems. Rapid chloride migration tests was conducted to investigate the chloride penetration profile. Based on the experimental results, the service life of repair systems was evaluated

Service life design for infrastructure

In the past few years more and more attention has been devoted to the safety and serviceability as well as durability and sustainability of structures. Meanwhile there are intensive research and development activities going on, e.g. on materials properties, deterioration mechanisms, geometric- and structural design, execution aspect and maintenance. Furthermore, codes and standards on service life design are being discussed and partially established world wide. It is now time to present a focused picture of the current status and future trends in this field, including theory, practice and education. The aim of the symposium is to provide a forum to researchers and practitioners for presenting the newest findings and to discuss new ideas on service life design and serviceability of infrastructural Works, effectiveness of service life design methods and experiences from the practice

Discriminative Cooperative Networks for Detecting Phase Transitions

The classification of states of matter and their corresponding phase transitions is a special kind of machine-learning task, where physical data allow for the analysis of new algorithms, which have not been considered in the general computer-science setting so far. Here we introduce an unsupervised machine-learning scheme for detecting phase transitions with a pair of discriminative cooperative networks (DCN). In this scheme, a guesser network and a learner network cooperate to detect phase transitions from fully unlabeled data. The new scheme is efficient enough for dealing with phase diagrams in two-dimensional parameter spaces, where we can utilize an active contour model -- the snake -- from computer vision to host the two networks. The snake, with a DCN "brain", moves and learns actively in the parameter space, and locates phase boundaries automatically

Discrete particle simulation of the homogeneous fluidization of Geldart A particles

The homogeneous fluidization of Geldart A particles has been studied with a 2D soft-sphere discrete particle model. We find that the homogeneous fluidization regime represents a quasi-equilibrium state where the force balance exists at the macroscopic-level, but not at the level of individual particles. The velocity fluctuation of particles is an exponential function of the squared superficial gas velocity in the homogeneous fluidization regime, not a linear function as found by\ud Cody et al

Effect of impurities on the transition between minority ion and mode conversion ICRH heating in (3He)-H tokamak plasmas

Hydrogen majority plasmas will be used in the initial non-activated phase of ITER operation. Optimizing ion cyclotron resonance heating (ICRH) in such scenarios will help in achieving H-mode in these plasmas. Past JET experiments with the carbon wall revealed a significant impact of intrinsic impurities on the ICRH performance in (3He)-H plasmas relevant for the full-field initial ITER phase. High plasma contamination with carbon impurities resulted in the appearance of a supplementary mode conversion layer and significant reduction in the transition concentration of 3He minority ions, defined as the concentration at which the change from minority heating to mode conversion regime occurs. In view of the installation of the new ITER-like wall at JET, it is important to evaluate the effect of Be and W impurities on ICRH scenarios in (3He)-H plasmas. In this paper, an approximate analytical expression for the transition concentration of 3He minority ions is derived as a function of plasma and ICRH parameters, and accounting for typical impurity species at JET. The accompanying 1D wave modeling supports the analytical results and suggests a potential experimental method to reduce 3He level needed to achieve a specific heating regime by puffing a small amount of 4He ions additionally to (3He)-H plasma.Comment: 23 pages, 9 figure

Are waves all localized in two dimensional random media?

It has been the dominant view for over two decades that all waves are localized in two dimensions for any given amount of disorder. Here, I would like to raise questions about this assertion. The discussion leads to the conclusion that there is a lack of the conclusive and definite support of the claim. Rather, the recent evidence tends to indicate that waves are not necessarily always localized in two dimensional random systems. Reasons are elaborated

Magneto-quantum oscillations of the conductance of a tunnel point-contact in the presence of a single defect

The influence of a quantizing magnetic field $H$ to the conductance of a tunnel point contact in the presence of the single defect has been considered. We demonstrate that the conductance exhibits specific magneto-quantum oscillations, the amplitude and period of which depend on the distance between the contact and the defect. We show that a non-monotonic dependence of the point-contact conductance results from a superposition of two types of oscillations: A short period oscillation arising from electron focusing by the field $H$ and a long period oscillation of Aharonov-Bohm-type originated from the magnetic flux passing through the closed trajectories of electrons moving from the contact to the defect and returning back to the contact.Comment: 13 pages, 3 figure