Non Linear Bilinear Type Models to Forecast Critical Dry Spell Lengths in Anamaduwa, Sri Lanka

2016 ◽  
Keyword(s):  
Sri Lanka ◽  
Dry Spell ◽  
Non Linear

scholarly journals An optimal lockdown relaxation strategy for minimizing the economic effects of covid-19 outbreak in Sri Lanka

2020 ◽  
Author(s):  
A.C. Mahasinghe ◽  
K.K.W.H. Erandi ◽  
S.S.N. Perera
Keyword(s):  
Sri Lanka ◽  
Optimization Model ◽  
Preventive Measures ◽  
Economic Effects ◽  
Gradual Transition ◽  
Separable Programming ◽  
Non Linear

AbstractIn order to recover the damage to the economy by the ongoing covid-19 pandemic, Sri Lanka is undergoing a gradual transition from strict lockdowns to partial lockdowns through relaxation of curfew and other moderated preventive measures. In this work, we propose an optimal lockdown relaxation strategy, which is aimed at minimizing the damage to the economy, while confining the covid-19 incidence to a level endurable by the available healthcare capacity in the country. The relevant optimization model turns out to be non-linear. We use the technique of separable programming to generate solutions and discuss the results.

scholarly journals Assessment of Climate Variability for Coconut and Other Crops: A Statistical Approach

CORD ◽  
2008 ◽  
Vol 24 (1) ◽  
pp. 19
Author(s):  
T.S.G. Peiris
Keyword(s):  
Sri Lanka ◽  
Climate Variability ◽  
Air Temperature ◽  
Agricultural Sector ◽  
Maximum Temperature ◽  
Climate Data ◽  
Dry Spells ◽  
Rate Of Increase ◽  
Dry Spell ◽  
Maximum Air Temperature

Public opinion in Sri Lanka has been seriously concerned about the possible impact of climate change on different sectors, and in particular for the agricultural sector. Annual and weekly climate data were analyzed to provide useful information to farmers, planners and scientists to assess the suitability of different types of crops. The statistical methodology of the analysis is illustrated using daily rainfall and air temperature from 1951 to 2001 for Hambantota, a major coconut growing district in Sri Lanka. The increase in maximum air temperature and decrease in the amount of rainfall per effective rainy day (> 5mm) are the significant features of the climate variability in the Hambantota area. The warming rate for maximum air temperature was significantly higher (p<0.005) than that for minimum, mean and diurnal temperature, irrespective of time scales. The annual rate of increase of maximum temperature after 1995 is 0.0260C. The intensity of rainfall per effective rainy day (> 5mm) decreased significantly (p<0.005). Distribution of weekly rainfall during January to September is uncertain. The probability of weekly rainfall greater than 20 mm does not exceed 50% in any week during this period. Long-term weekly rainfall was greater than 30 mm only during mid October to early December, but the probability of weekly rainfall greater than 30 mm exceeds 50% only during the first three weeks of November. The probability of occurrence of dry spells of duration greater than 60 days in a year is around 70%, but the time of occurrence of such dry spell is not consistent among years. These findings suggest that the expected future climate would not be suitable for coconut cultivation, if growers do not apply the recommended practices to face long dry spells. Also the increasing temperature could impact to dominate plant pest during dry periods.

Decision tree application for model built-up land fragmentation in urban areas

2021 ◽  
Author(s):  
Nesha Ranaweera ◽  
◽  
Amila Jayasinghe ◽  
Chethika Abenayake ◽  
◽  
...  
Keyword(s):  
Land Use ◽  
Sustainable Development ◽  
Sri Lanka ◽  
Decision Tree ◽  
Urban Areas ◽  
Land Use Changes ◽  
Land Fragmentation ◽  
Western Province ◽  
Linear Relationships ◽  
Non Linear

Land fragmentation can define as the “situation where one area/unit is composed of a large number of parcels that are too small for their rational utilization” [5]. Land fragmentation affects sustainable development through its multiple impacts on environmental, economic, and social costs [13]. Effective land use management and policy decisions are always based on understanding, modeling, and predicting land-use changes in cities [9]. Therefore, the land fragmentation process should systematically investigate to provide a wide-ranging set of land use indicators to support sustainable development [12]. Built-up land fragmentation is the fragmentation or division of the built-up plots or units within the built-up land-use area horizontally. The objective of this study is to frame a Decision Tree (DT) model to identify the non-linear relationships between the Level of Built-up Land Fragmentation (LBLF) and its influencing factors in urban areas. The sub-objective is to quantify the LBLF in the Western Province, Sri Lanka. The study scope limits to LBLF and Decision Tree (DT) non-linear classifier. The study further quantifies the LBLF from 2000 to 2010 in Western Province, Sri Lanka as an initiation to frame the DT model.

Carbon limits non-linear response of nitrous oxide (N2O) to increasing N inputs in a highly-weathered tropical soil in Sri Lanka

2020 ◽  
Vol 292 ◽  
pp. 106808 ◽  
Author(s):  
Anuga Liyanage ◽  
Peter R Grace ◽  
Clemens Scheer ◽  
Daniele de Rosa ◽  
Sudheera Ranwala ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Sri Lanka ◽  
Linear Response ◽  
Tropical Soil ◽  
Non Linear

B. The Non-Linear Calculations for Pulsating Stars

1967 ◽  
Vol 28 ◽  
pp. 105-176
Author(s):  
Robert F. Christy
Keyword(s):  
Major Part ◽  
Afternoon Session ◽  
Discussion Session ◽  
Pulsating Stars ◽  
Fourth Symposium ◽  
Non Linear ◽  
Considerable Discussion ◽  
Informal Approach ◽  
Preceding Session

(Ed. note: The custom in these Symposia has been to have a summary-introductory presentation which lasts about 1 to 1.5 hours, during which discussion from the floor is minor and usually directed at technical clarification. The remainder of the session is then devoted to discussion of the whole subject, oriented around the summary-introduction. The preceding session, I-A, at Nice, followed this pattern. Christy suggested that we might experiment in his presentation with a much more informal approach, allowing considerable discussion of the points raised in the summary-introduction during its presentation, with perhaps the entire morning spent in this way, reserving the afternoon session for discussion only. At Varenna, in the Fourth Symposium, several of the summaryintroductory papers presented from the astronomical viewpoint had been so full of concepts unfamiliar to a number of the aerodynamicists-physicists present, that a major part of the following discussion session had been devoted to simply clarifying concepts and then repeating a considerable amount of what had been summarized. So, always looking for alternatives which help to increase the understanding between the different disciplines by introducing clarification of concept as expeditiously as possible, we tried Christy's suggestion. Thus you will find the pattern of the following different from that in session I-A. I am much indebted to Christy for extensive collaboration in editing the resulting combined presentation and discussion. As always, however, I have taken upon myself the responsibility for the final editing, and so all shortcomings are on my head.)

Abstract #604: Detection of Cardiovascular Risk Factors by Anthropometric Measures in Adults Living in an Urban Setting in Sri Lanka

2015 ◽  
Vol 21 ◽  
pp. 114-115
Author(s):  
Kavinga Gunawardane ◽  
Noel Somasundaram ◽  
Neil Thalagala ◽  
Pubudu Chulasiri ◽  
Sudath Fernando
Keyword(s):  
Risk Factors ◽  
Cardiovascular Risk ◽  
Sri Lanka ◽  
Cardiovascular Risk Factors ◽  
Urban Setting ◽  
Anthropometric Measures

A decomposition method in non-linear programmm

Optimization ◽  
1975 ◽  
Vol 6 (4) ◽  
pp. 549-559
Author(s):  
L. Gerencsér
Keyword(s):  
Decomposition Method ◽  
Non Linear
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