•We present a multi-objective optimization to stabilize power systems using PSSs.•The PSSs locations and their numbers are optimized using participation factor and GA.•The optimization will maximize ...the damping ratio of the electromechanical modes.•The resulting stabilizer is tested on the 16-machine 68-bus under various operating conditions.•We compared the approach with two other methods, which use only GA.
This paper describes a method to determine the optimal location and the number of multi-machine power system stabilizers (PSSs) using participation factor (PF) and genetic algorithm (GA). The PF method is primarily used for number estimation and to identify the location of the PSSs, while the GA is applied to further reduce the number of PSSs, resulting in the optimization of their parameters and locations under different operating conditions. The problem is presented as a multi-objective optimization problem; maximizing the damping ratio of the electromechanical modes using different numbers of PSSs. The approach is successfully tested on the New England–New York interconnected system (16-machine and 68-bus), and its effectiveness in damping of local and inter-area modes of oscillations was proven. It is also compared to two other methods, which use only GA, in terms of damping ratio and computation time. In addition, the proposed approach demonstrates better performance compared to a fuzzy-based PSS when applied to the Iraqi National Super Grid System (INSGS).
Purpose – This study examined the types of written corrective feedback provided to ESL students in writing classes in Malaysian secondary schools, and their perceptions towards the provision of ...written corrective feedback in the Malaysian context. Methodology – A survey questionnaire was administered randomly among 720 Form Four students from 10 secondary schools in Penang. The questionnaire was based on a Likert scale and responses were analysed using descriptive statistics. Findings – Results showed that most learners benefited from and preferred direct feedback, and tended to focus on form such as grammar, paragraph organisation, content and clarity of ideas. Students preferred this form of feedback as they were able to understand errors more clearly. It was found that most students were unable to self-regulate their own errors; a majority could not locate their own errors and had become passive learners within the Malaysian schooling system. Significance – The study is significant to Malaysian secondary schools in its effects, depicting the many forms of corrective feedback available in the ESL context that can be employed in school besides the popularized direct feedback used within the syllabus.
Purpose – This study examined the types of written corrective feedback provided to ESL students in writing classes in Malaysian secondary schools, and their perceptions towards the provision of ...written corrective feedback in the Malaysian context. Methodology – A survey questionnaire was administered randomly among 720 Form Four students from 10 secondary schools in Penang. The questionnaire was based on a Likert scale and responses were analysed using descriptive statistics. Findings – Results showed that most learners benefited from and preferred direct feedback, and tended to focus on form such as grammar, paragraph organisation, content and clarity of ideas. Students preferred this form of feedback as they were able to understand errors more clearly. It was found that most students were unable to self-regulate their own errors; a majority could not locate their own errors and had become passive learners within the Malaysian schooling system. Significance – The study is significant to Malaysian secondary schools in its effects, depicting the many forms of corrective feedback available in the ESL context that can be employed in school besides the popularized direct feedback used within the syllabus.
Over groundwater exploitation owing to population, urbanization and industrialization make the groundwater unfavorable for living beings. This study deals with the assessment of groundwater quality ...in Gudiyattam and Vaniyambadi blocks of Vellore district, Tamil Nadu India, where groundwater is the major source of drinking due to deficiency in surface water. The significant physicochemical parameters such as pH, conductivity, total dissolved solids, chlorides, total alkalinity, calcium hardness, magnesium hardness and sulphate were assessed. Correlation matrix, box plot, multivariate statistical tools such as cluster analysis and principal component analysis were applied to groundwater quality analysis. The groundwater samples were assessed for its applicability in irrigation and drinking purposes and geographic information system techniques are used for mapping consequence. The parameters analyzed were compared with Bureau of Indian Standards and WHO standards. Box plot analysis revealed that total dissolved solids and electrical conductivity was strongly correlated. Correlation analysis exhibits strong correlation between total dissolved solids and electrical conductivity, anions such as Ca super( 2+) and Mg super( 2+) for both the study areas.
In this paper, we solve the general solution in vector space and prove the Hyers-Ulam stability of the following additive functional equationin paranormed spaces by using the direct and fixed point ...methods. Also we present its pertinent counter examples for instabilities.
Tuberculosis is an age old disease caused by Mycobacterium tuberculosis which has been a menace to public health and thwarting economic growth. Pulmonary tuberculosis being the most common type, ...extra pulmonary tuberculosis has a greater association with HIV and multidrug resistant tuberculosis. Cutaneous tuberculosis accounts for 1–1.5 % of extra pulmonary tuberculosis.
A 32 year old female presented to the outpatient department with a two month history of ulcer over the sole of the foot with multiple discharging sinuses and surrounding induration. Laboratory tests reported elevated total leukocyte counts. Magnetic Resonance Imaging of the foot showed diffuse intermuscular edema with an interconnecting sinus tract draining to the sole of the foot. Regular wound dressings and antibiotics showed no resolution. Patient eventually underwent near complete excision of the ulcer. The biopsy was suggestive of tuberculous etiology. She achieved complete resolution with antituberculous drugs by three months.
Cutaneous tuberculosis is often misdiagnosed as it can masquerade as many other commonly encountered dermatological conditions. Microbiological diagnosis plays a crucial role in the accurate diagnosis of cutaneous tuberculosis. These lesions are highly responsive to antituberculous drugs.
Cutaneous tuberculosis is a rare disease that should be considered in the differential diagnosis of patients with chronic non-healing wounds that are poorly responsive to conventional treatment methods.
•Cutaneous tuberculosis is an extremely rare disease often misdiagnosed•The diagnosis of true cutaneous tuberculosis is established by Acid Fast Bacilli staining, MGIT \ or CBNAAT \•The lesions of cutaneous tuberculosis are extremely responsive to antitubercular drugs.
Pattern Identification in Biogeography Ganapathy, G.; Goodson, B.; Jansen, R. ...
IEEE/ACM transactions on computational biology and bioinformatics,
10/2006, Letnik:
3, Številka:
4
Journal Article
Recenzirano
Identifying common patterns among area cladograms that arise in historical biogeography is an important tool for biogeographical inference. We develop the first rigorous formalization of these ...pattern-identification problems. We develop metrics to compare area cladograms. We define the maximum agreement area cladogram (MAAC) and we develop efficient algorithms for finding the MAAC of two area cladograms, while showing that it is NP-hard to find the MAAC of several binary area cladograms. We also describe a linear-time algorithm to identify if two area cladograms are identical
Soil bioengineering is the concept of utilizing plants, including its roots, to strengthen or stabilize soils with poor engineering properties such as soils in natural and manmade slopes. This ...technique is widely used in many countries and is also practised in India. Most of the research works done related to soil bio engineering are by ecological researchers, geotechnical research works related to utilizing the plant roots as reinforcement are few in India. In this research works, an attempt is made to study the strength variation in a landslide-affected soil by stabilizing the soil with plant roots obtained from readily available plants in the study area. The roots were obtained and a particular root mass (Lemon grass root) was introduced in the soil and the geotechnical property changes were verified. It was found that the incorporation of the plant roots in the soil matrix improved the stability of the soil. Consequently, the plant roots studied can be cheap materials for improving the stability of slopes, especially in landslide-affected areas.
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