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51.
Many developing world cities have seen the emergence of informal markets where private tanker truck operators transport water extracted from peri-urban wells to urban consumers. This study adopted a systems-modelling approach to analyzing the informal tanker market in India. The results indicate that the demand for tanker supply was caused by lack of groundwater availability in private wells as well as unreliable piped supply. The study shows that two groundwater factors are relevant: depth to water and aquifer productivity. Together, these could explain the difference in spatial, temporal and consumer-specific variations in tanker dependence. 相似文献
52.
Stephen Muggleton Luc De Raedt David Poole Ivan Bratko Peter Flach Katsumi Inoue Ashwin Srinivasan 《Machine Learning》2012,86(1):3-23
Inductive Logic Programming (ILP) is an area of Machine Learning which has now reached its twentieth year. Using the analogy
of a human biography this paper recalls the development of the subject from its infancy through childhood and teenage years.
We show how in each phase ILP has been characterised by an attempt to extend theory and implementations in tandem with the
development of novel and challenging real-world applications. Lastly, by projection we suggest directions for research which
will help the subject coming of age. 相似文献
53.
Adsorption cryocoolers are among the possible options for obtaining cryogenic temperatures, in particular for small cooling capacity applications such as cooling of infra red detectors. They need to be optimized for liquid yield. The performance of thermal compressors therein pivots around the adsorption characteristics of the adsorbent + adsorbate combination and how effectively one could pack requisite amounts of adsorbent into a given volume of the compressor housing. In addition, the overall performance of the cooler is a function of limits of operating temperatures and pressures across the compressor. This paper proposes a performance indicator—the product of liquid yield and the uptake efficiency of the compressor—and evaluates its values for various possible operating conditions for one specimen of activated carbon. It is shown that there is a limited domain of operation and that there is a condition of best performance within that domain. 相似文献
54.
Phantom-based haptic interaction with virtual objects 总被引:1,自引:0,他引:1
In 1993, haptic interaction with computers took a significant step forward with the development of the Phantom haptic interface. This simple device has spawned a new field analogous to computer graphics-computer haptics-defined as the discipline concerned with the techniques and processes associated with generating and displaying synthesized haptic stimuli to the human user. Inspired by the authors' previous work in interpreting robot touch sensor information and study of human touch perception, the Phantom interface permits users to feel the forces of interaction they would encounter while touching objects with the end of a stylus or the tip of their finger. The resulting sensations prove startling, and many first-time users are quite surprised at the compelling sense of physical presence they encounter when touching virtual objects. To appreciate why the Phantom system succeeded where others failed, you need to understand the nature and functioning of the human haptic system. 相似文献
55.
V. S. Srinivasan R. Sandhya M. Valsan K. Bhanu Sankara Rao S. L. Mannan 《International Journal of Fatigue》2004,26(12):1384-1302
The effect of 20% prior cold work on low cycle fatigue (LCF) behaviour of type 316L(N) stainless steel (SS) was studied at 873 K by conducting total axial strain controlled tests in air with strain amplitudes in the range ±0.25% to ±1.0%. The cyclic deformation behaviour of 20% prior cold worked (PCW) material was compared with the LCF response of solution annealed (SA) alloy tested under similar conditions. The cyclic stress response (CSR) of 316L(N) SS in the PCW condition was characterized by a short period of hardening followed by prolonged softening prior to failure, whereas SA material exhibited a significant hardening regime followed by stress saturation. Interrupted tests on PCW material were carried out at different stages of CSR in order to determine the underlying mechanisms as reflected in substructural changes. The fatigue life in the solution annealed condition was similar to that of the PCW material at higher strain amplitudes of testing (≥±0.5%) while at lower strain amplitudes, the PCW material exhibited longer life. 相似文献
56.
Heungsoon Felix Lee Mandyam M. Srinivasan Candace Arai Yano 《International Journal of Flexible Manufacturing Systems》2006,18(4):239-268
We consider the problem of simultaneously determining the number of machines (and/or workers), the assignment of tasks (and
related tools and components) to these machines, and the number of jobs circulating in a flexible assembly system (FAS), to
satisfy steady-state throughput requirements for a family of similar products at minimum cost. We focus on situations where
there are precedence relations among the various tasks, as is common in assembly systems. We present a framework for solving
this problem based on a heuristic decomposition approach which involves the solution of only a few types of sub-problems.
We demonstrate the efficiency and effectiveness of the overall procedure using a number of example problems. 相似文献
57.
Nitesh K. Gupta Srinivasan Jayakumar Wen-Chieh Huang Pieter Leyssen Johan Neyts Sergey O. Bachurin Jih Ru Hwu Shwu-Chen Tsay 《International journal of molecular sciences》2022,23(20)
The yellow fever virus (YFV) is an emerging RNA virus and has caused large outbreaks in Africa and Central and South America. The virus is often transmitted through infected mosquitoes and spreads from area to area because of international travel. Being an acute viral hemorrhagic disease, yellow fever can be prevented by an effective, safe, and reliable vaccine, but not be eliminated. Currently, there is no antiviral drug available for its cure. Thus, two series of novel bis(benzofuran–1,3-imidazolidin-4-one)s and bis(benzofuran–1,3-benzimidazole)s were designed and synthesized for the development of anti-YFV lead candidates. Among 23 new bis-conjugated compounds, 4 of them inhibited YFV strain 17D (Stamaril) on Huh-7 cells in the cytopathic effect reduction assays. These conjugates exhibited the most compelling efficacy and selectivity with an EC50 of <3.54 μM and SI of >15.3. The results are valuable for the development of novel antiviral drug leads against emerging diseases. 相似文献
58.
Kathleen Louis-Gray Srinivasan Tupal Louis S. Premkumar 《International journal of molecular sciences》2022,23(17)
The most common medicinal claims for cannabis are relief from chronic pain, stimulation of appetite, and as an antiemetic. However, the mechanisms by which cannabis reduces pain and prevents nausea and vomiting are not fully understood. Among more than 450 constituents in cannabis, the most abundant cannabinoids are Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Cannabinoids either directly or indirectly modulate ion channel function. Transient receptor potential vanilloid 1 (TRPV1) is an ion channel responsible for mediating several modalities of pain, and it is expressed in both the peripheral and the central pain pathways. Activation of TRPV1 in sensory neurons mediates nociception in the ascending pain pathway, while activation of TRPV1 in the central descending pain pathway, which involves the rostral ventral medulla (RVM) and the periaqueductal gray (PAG), mediates antinociception. TRPV1 channels are thought to be implicated in neuropathic/spontaneous pain perception in the setting of impaired descending antinociceptive control. Activation of TRPV1 also can cause the release of calcitonin gene-related peptide (CGRP) and other neuropeptides/neurotransmitters from the peripheral and central nerve terminals, including the vagal nerve terminal innervating the gut that forms central synapses at the nucleus tractus solitarius (NTS). One of the adverse effects of chronic cannabis use is the paradoxical cannabis-induced hyperemesis syndrome (HES), which is becoming more common, perhaps due to the wider availability of cannabis-containing products and the chronic use of products containing higher levels of cannabinoids. Although, the mechanism of HES is unknown, the effective treatment options include hot-water hydrotherapy and the topical application of capsaicin, both activate TRPV1 channels and may involve the vagal-NTS and area postrema (AP) nausea and vomiting pathway. In this review, we will delineate the activation of TRPV1 by cannabinoids and their role in the antinociceptive/nociceptive and antiemetic/emetic effects involving the peripheral, spinal, and supraspinal structures. 相似文献
59.
Xiaoyu Che Christopher R. Brydges Yuanzhi Yu Adam Price Shreyas Joshi Ayan Roy Bohyun Lee Dinesh K. Barupal Aaron Cheng Dana March Palmer Susan Levine Daniel L. Peterson Suzanne D. Vernon Lucinda Bateman Mady Hornig Jose G. Montoya Anthony L. Komaroff Oliver Fiehn W. Ian Lipkin 《International journal of molecular sciences》2022,23(14)
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic and debilitating disease characterized by unexplained physical fatigue, cognitive and sensory dysfunction, sleeping disturbances, orthostatic intolerance, and gastrointestinal problems. People with ME/CFS often report a prodrome consistent with infections. Using regression, Bayesian and enrichment analyses, we conducted targeted and untargeted metabolomic analysis of plasma from 106 ME/CFS cases and 91 frequency-matched healthy controls. Subjects in the ME/CFS group had significantly decreased levels of plasmalogens and phospholipid ethers (p < 0.001), phosphatidylcholines (p < 0.001) and sphingomyelins (p < 0.001), and elevated levels of dicarboxylic acids (p = 0.013). Using machine learning algorithms, we were able to differentiate ME/CFS or subgroups of ME/CFS from controls with area under the receiver operating characteristic curve (AUC) values up to 0.873. Our findings provide the first metabolomic evidence of peroxisomal dysfunction, and are consistent with dysregulation of lipid remodeling and the tricarboxylic acid cycle. These findings, if validated in other cohorts, could provide new insights into the pathogenesis of ME/CFS and highlight the potential use of the plasma metabolome as a source of biomarkers for the disease. 相似文献
60.
In this paper, we consider a class of nonlinear fractional order control system with delay in state variable. Existence and uniqueness of solution are shown by using method of steps. The sensitivity of the state and control with respect to the parameters of the system is shown. Finally, analytical results are substantiated by numerical examples. 相似文献