4,162 research outputs found
Chryseobacterium indologenes improves survival of the Chromobacterium violaceum and violacein production
Chromobacterium violaceum is a human opportunistic pathogen which appears in soil and water environments. It produces a purple-colored bactericide named violacein. The aim of this study was to investigate the correlation between violacein production and the competitive ability of C. violaceum in co-culture with other soil bacteria. The C. violaceum (3), Chryseobacterium indologenes (1), Serratia marcescens (2), Pantoea agglomerans (4 and 5), Enterobacter asburiae (6) and Bacillus megaterium (7), were isolated together from a nest of Crematogaster biroi. In the duel species competition experiments, C. violaceum (3) inhibited the growth of C. indologenes (1), while being dramatically inhibited by S. marcescens (2). The growth of C. violaceum (3) was unaffected by P. agglomerans (4 and 5) and E. asburiae (6), but it was slightly reduced by B. megaterium (7) (after 48 h of incubation). In the multiple competition experiments, the survival of C. violaceum (3) was increased in the presence of C. indologenes (1). The production of violacein was reduced in co-culture with all the examined bacterial strains, except C. indologenes (1). The violacein degradation assay demonstrated that, S. marcescens (2), P. agglomerans (4 and 5) and E. asburiae (6) were capable of decolorizing violacein, while C. indologenes (1) and B. megaterium (7) had no effect on violacein stability in 24 h of incubation. Taken together, these results might be useful for industrial violacein production.Key words: Chromobacterium violaceum, Chryseobacterium indologenes, growth competition, violacein
Comparison of hybrid-excitation fault-tolerant in-wheel motor drives for electric vehicles
Paper no. DS2-23Hybrid-excitation in-wheel motor drive receives the attractive merit for its fault-tolerant operation. This paper gives the performance comparison of three types of hybrid-excitation in-wheel motor drives in electric vehicles (EVs) for their fault-tolerant operations. By using finite-time element analysis, the torque output is utilized as the fault indicator to investigate the performances of each motor drive under normal, faulty, and remedial operations.published_or_final_versio
Tracking advanced persistent threats in critical infrastructures through opinion dynamics
Advanced persistent threats pose a serious issue for modern industrial environments, due to their targeted and complex attack vectors that are difficult to detect. This is especially severe in critical infrastructures that are accelerating the integration of IT technologies. It is then essential to further develop effective monitoring and response systems that ensure the continuity of business to face the arising set of cyber-security threats. In this paper, we study the practical applicability of a novel technique based on opinion dynamics, that permits to trace the attack throughout all its stages along the network by correlating different anomalies measured over time, thereby taking the persistence of threats and the criticality of resources into consideration. The resulting information is of essential importance to monitor the overall health of the control system and cor- respondingly deploy accurate response procedures. Advanced Persistent Threat Detection Traceability Opinion Dynamics.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Preventing Advanced Persistent Threats in Complex Control Networks
An Advanced Persistent Threat (APT) is an emerging attack against Industrial Control and Automation Systems, that is executed over a long period of time and is difficult to detect. In this context, graph theory can be applied to model the interaction among nodes and the complex attacks affecting them, as well as to design recovery techniques that ensure the survivability of the network. Accordingly, we leverage a decision model to study how a set of hierarchically selected nodes can collaborate to detect an APT within the network, concerning the presence of changes in its topology. Moreover, we implement a response service based on redundant links that dynamically uses a secret sharing scheme and applies a flexible routing protocol depending on the severity of the attack. The ultimate goal is twofold: ensuring the reachability between nodes despite the changes and preventing the path followed by messages from being discovered.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Magnetic vibration analysis of a new DC-excited multitoothed switched reluctance machine
GQ - Electrical Machines for industrial and automotive applicationsThis journal issue contains selected papers from the 2014 IEEE International Magnetics (INTERMAG) ConferenceThis paper proposes a combined numerical and analytical approach for magnetic vibration analysis of a new dc-excited multitoothed switched reluctance (MSR) machine. First, the machine design is artfully to incorporate the dc-excited winding into the MSR topology, hence breeding a new flux controllable, high-torque, low-torque ripple, and doubly salient magnetless machine. Then, the finiteelement-method is used to calculate the machine force and torque. A series of analytical equations are formulated to calculate the magnetic vibration parameters of the proposed machine. The analysis process and the corresponding results are given to verify the validity of the proposed approach for magnetic vibration analysis of the new machine.published_or_final_versio
Multiple-receptor wireless power transfer for magnetic sensors charging on Mars via magnetic resonant coupling
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A study of resiliency among Chinese health care workers: Capacity to cope with workplace stress
This paper reports a study of resiliency to cope with workplace stress among Chinese health care workers. We adopted a qualitative-quantitative-biomarker approach to conduct interviews, focus group discussions, and a two-wave longitudinal survey. Wave 1 survey was conducted among health care workers in Hong Kong and Mainland China (N = 773). Amongst them, 287 took part in Wave 2 survey. A confirmatory factor analysis consistently supported a 9-item scale. A sub-sample's (N = 33) resiliency was positively related to salivary IgA levels (an immune marker). Results from hierarchical regressions demonstrated that resiliency measured in Wave 1 was positively related to job satisfaction, work-life balance, and quality of life; and negatively related to physical/psychological symptoms and injuries at work in Wave 2. © 2009 Elsevier Inc. All rights reserved.postprin
The effect of cigarette price increase on the cigarette consumption in Taiwan: evidence from the National Health Interview Surveys on cigarette consumption
BACKGROUND: This study uses cigarette price elasticity to evaluate the effect of a new excise tax increase on cigarette consumption and to investigate responses from various types of smokers. METHODS: Our sample consisted of current smokers between 17 and 69 years old interviewed during an annual face-to-face survey conducted by Taiwan National Health Research Institutes between 2000 to 2003. We used Ordinary Least Squares (OLS) procedure to estimate double logarithmic function of cigarette demand and cigarette price elasticity. RESULTS: In 2002, after Taiwan had enacted the new tax scheme, cigarette price elasticity in Taiwan was found to be -0.5274. The new tax scheme brought about an average annual 13.27 packs/person (10.5%) reduction in cigarette consumption. Using the cigarette price elasticity estimate from -0.309 in 2003, we calculated that if the Health and Welfare Tax were increased by another NT$ 3 per pack and cigarette producers shifted this increase to the consumers, cigarette consumption would be reduced by 2.47 packs/person (2.2%). The value of the estimated cigarette price elasticity is smaller than one, meaning that the tax will not only reduce cigarette consumption but it will also generate additional tax revenues. Male smokers who had no income or who smoked light cigarettes were found to be more responsive to changes in cigarette price. CONCLUSIONS: An additional tax added to the cost of cigarettes would bring about a reduction in cigarette consumption and increased tax revenues. It would also help reduce incidents smoking-related illnesses. The additional tax revenues generated by the tax increase could be used to offset the current financial deficiency of Taiwan's National Health Insurance program and provide better public services
Study of motoring operation of in-wheel switched reluctance motor drives for electric vehicles
Author name used in this publication: X. D. XueAuthor name used in this publication: K. W. E. ChengAuthor name used in this publication: N. C. CheungAuthor name used in this publication: Z. ZhangAuthor name used in this publication: J. K. LinRefereed conference paper2008-2009 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
From counting to construction of BPS states in N=4 SYM
We describe a universal element in the group algebra of symmetric groups,
whose characters provides the counting of quarter and eighth BPS states at weak
coupling in N=4 SYM, refined according to representations of the global
symmetry group. A related projector acting on the Hilbert space of the free
theory is used to construct the matrix of two-point functions of the states
annihilated by the one-loop dilatation operator, at finite N or in the large N
limit. The matrix is given simply in terms of Clebsch-Gordan coefficients of
symmetric groups and dimensions of U(N) representations. It is expected, by
non-renormalization theorems, to contain observables at strong coupling. Using
the stringy exclusion principle, we interpret a class of its eigenvalues and
eigenvectors in terms of giant gravitons. We also give a formula for the action
of the one-loop dilatation operator on the orthogonal basis of the free theory,
which is manifestly covariant under the global symmetry.Comment: 41 pages + Appendices, 4 figures; v2 - refs and acknowledgments adde
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