Fuzzy image restoration using modulation transfer function

The key difficulty of restoring a fuzzy image is to estimate its point spread function( PSF). In the paper,PSF is modelled based on modulation transfer function( MTF). The first step is calculating the image MTF. In the traditional slanted-edge method,a sub-block is always manually extracted from original image and its MTF will be viewed as the result of the whole image. However,handcraft extraction is inefficient and will lead to inaccurate results. Given this,an automatic MTF computation algorithm is proposed,which extracts and screens out all the effective sub-blocks and calculates their average MTF as the final result. Then,a two-dimensional MTF restoration model is constructed by multiplying the horizontal and vertical MTF,and it is combined with conventional image restoration methods to restore fuzzy image. Experimental results indicate the proposed method implementes a fast and accurate MTF computation and the MTF model improves the performance of conventional restoration methods significantly.

Assessing the effectiveness of disaster risk reduction strategies on the regional recovery of critical infrastructure systems

Communities depend on critical infrastructure systems to support their regular operations and future develop-ment.Destructive events,such as natural disasters,threaten to disrupt service to these systems and the commu-nities they support.Strategies designed to reduce the impacts from disasters and other events are therefore an important consideration for community planning.At a regional level,coordination between communities sup-ports the efficient use of resources for implementing disaster risk reduction(DRR)measures and completing post-disaster repairs to meet the needs of all residents.Coordination is challenging,however,due to the complex-ity of regional systems and competing stakeholder interests.This work presents a case study model of regional water,wastewater,and power systems,and demonstrates the effect of seismic hardening and increased resource availability on post-earthquake repair requirements and critical infrastructure recovery.Model results indicate that implementing DRR strategies can reduce required repair costs by over 40 percent and outage severity by approximately 50 percent for the studied sectors.Not all strategies are effective for all sectors and locations,how-ever,so this work discusses the importance of comprehensive,coordinated,and accessible emergency planning activities to ensure that the needs of all residents are considered.

Extended activated sludge model no. 1 (ASM1) for simulating biodegradation process using bacterial technology

Phosphorus is one of the most important nutrients required to support various kinds of biodegradation processes. As this particular nutrient is not included in the activated sludge model no. 1 （ASM1）, this study extended this model in order to determine the fate of phosphorus during the biodegradation processes. When some of the kinetics parameters are modified using observed data from the restoration project of the Xuxi River in Wuxi City, China, from August 25 to 31 in 2009, the extended model shows excellent results. In order to obtain optimum values of coefficients of nitrogen and phosphorus, the mass fraction method was used to ensure that the final results were reasonable and practically relevant. The temporal distribution of the data calculated with the extended ASM1 approximates that of the observed data.

Causes and Restoration of Degraded Alpine Grassland in Northern Tibet

Grassland in northern Tibet plays an important role in the eco-security of the Qinghai-Tibet Plateau and the restoration of deserte@and degraded grassland is now a focus for governments. We used remote sensing, simulations and field surveys to analyze the current status, trends and causes of grassland degradation across northern Tibet. We develop several recovery models for degraded grassland based on field experiments in the region. We found that slightly degraded grassland covers 62% and that moderate to severely degraded grassland occupied 15.1% in the Chang Tang Plateau. The amount of degraded alpine steppe increased from 1991, and the amount of area classified as severely degraded increased sharply from 2000. The cause of degraded steppe in northwestern Tibet may be the result of warming and an arid climate; the cause of severe degradation in mid and eastern regions was mainly from overgrazing. Three restoration models are proposed for different levels of degradation： ＂enclosures＂ for slightly degraded areas, ＂enclosures with fertilization＂ for moderately degraded areas, and ＂enclosure with oversowing and fertilization＂ for severely degraded areas.