Optimization Models for Designing Spatially Compact Ecological Reserve Systems

Over the past decades, a number of mathematical models and solution techniques have been developed to preserve reserve sites for species and their natural habitats. Two optimization models for designing spatially compact ecological reserve systems are addressed here as zero-one integer programming problems. These formulations have a bicriteria objective function that is a combination of both boundary length and distance. The two formulations cluster the sites into a relatively small number of compact groups while preserving a required number of sites that contain a certain species using a given amount of resources. Two general types of approaches have been developed to solve the resulting mathematical models: exact and heuristic algorithms

Approximation in Multiobjective Optimization with Applications

Over the last couple of decades, the field of multiobjective optimization has received much attention in solving real-life optimization problems in science, engineering, economics and other fields where optimal decisions need to be made in the presence of trade-offs between two or more conflicting objective functions. The conflicting nature of objective functions implies a solution set for a multiobjective optimization problem. Obtaining this set is difficult for many reasons, and a variety of approaches for approximating it either partially or entirely have been proposed. In response to the growing interest in approximation, this research investigates developing a theory and methodology for representing and approximating solution sets of multiobjective optimization problems. The concept of the tolerance function is proposed as a tool for modeling representation quality. Two types of subsets of the set being represented, covers and approximations, are defined, and their properties are examined. In addition, approximating the solution set of the multiobjective set covering problem (MOSCP), one of the challenging combinatorial optimization problems that has seen limited study, is investigated. Two algorithms are proposed for approximating the solution set of the MOSCP, and their approximation quality is derived. A heuristic algorithm is also proposed to approximate the solution set of the MOSCP. The performance of each algorithm is evaluated using test problems. Since the MOSCP has many real-life applications, and in particular designing reserve systems for ecological species is a common field for its applications, two optimization models are proposed in this dissertation for preserving reserve sites for species and their natural habitats

Trends in the Sri Lankan Longline Tuna Fishing Effort (2015-2019): A GIS-Based Spatial-Temporal Analysis

Abstract The Fishing industry play a major role in socio-economic context of Sri Lanka. Even though, there is a significant potential to develop the fishing industry in country, the current economic performances of the industry are not satisfactory due to poor management mechanisms. It is essential to implement sustainable management approaches in order to achieve socio-economic and environmental sustainability. The analysis of the spatial and temporal distribution of fishery resources is an important step toward sustaining the resources. However, acquiring data about the distribution and spatiotemporal allocation of catch and fishing efforts in commercial marine fisheries remains challenging. This study aims to investigate the distribution pattern of the longline tuna fishery and identify sustainable fishing grounds in Sri Lanka. The study uses the fisheries data from VMS and logbook between 2015 until 2019, obtained from the Department of fisheries and aquatic resources. The socio-economic data were collected from thirty multiday boat fishermen covering the south, west and east coasts using a semi-structured questionnaire. The study is based on Geographic Information System (GIS) and descriptive statistical analysis. The results of the GIS-based analysis show high variations in catch and catch per trip distribution patterns by years and seasons. Hotspots of fishing efforts, catches (quantity) and catch per trips (CPT) were identified. The results show the areas of clusters with high CPT values increased slightly after 2016. The hotspots map show that there is strong seasonal influences in the concentration of fishing efforts and catches. The socio-economic results confirm that Sri Lankan longline fishers predominantly use traditional ecological knowledge (TEK) to determine their potential fishing zone. Natural signs such as birds, floating, group information, and extreme oceanographic conditions such as waves, wind, and currents were the main factors that longline fishers use to decide where they will go fishing. The effective visualization and communication of identified and mapped seasonal, and annual as well as persistent and sustainable fishing grounds maps to stakeholders and managers may provide a great opportunity to sustainable management of fisheries in Sri Lanka. Moreover, the study shows the importance of integrating TEK to understand the fishers behavior in space and time and to support sustainable management of the fishery system

Actomyosin Contractility in Nonmuscle Cells

Forces and stresses generated by the action of myosin minifilaments are analyzed via simulation of their motion in idealized computer-generated random, isotropic actin networks and actin bundles. The networks and bundles are generated as random collections of actin filaments in two dimensions with constrained orientations, crosslinked and attached to fixed walls: four walls for isotropic networks, two for bundles). Myosin minifilaments are placed on actin filament pairs and allowed to move and deform the network so that it exerts forces on the walls. The stresses are overwhelmingly contractile in both cases, because minifilament equilibrium positions having contractile stress have lower energy than those for expansive stress. Mini-filaments rotate into these energetically stable contractile configurations. This process is aided by the bending of actin filaments, which accomodates mini-filament rotation. The presence of force chains leads to unexpectedly large stresses especially in the random networks. Stresses for bundles are greater than those for isotropic networks, and antiparallel filaments generate more tension than parallel filaments. The forces transmitted by the actin network to the walls of the simulation cell often exceed the tension in the minifilament itself

Evaluation of the coastal inundation and erosion process in the Mid-West coast of Western Australia

This study focused on the coastal inundation and erosion process in the Mid-West Coast of Western Australia. The process was evaluated for 1, 100 and 500 ARI events with future sea level rise using numerical modelling method. Statistical method was used to determine the extreme water level, wave and wind for selected ARI events. Overall modelling results clearly show that future climate change and sea level rise have adverse impacts on the selected coastal region

The Efficacy of Providing Counselling and Psychological Support To Employee Engagement At Work Places

In today’s data driven business climate, there is almost no company that does not have stressed workers. The global economyis considerably shifting and exponentially accelerating the need for organizations to address challenges imposed by technological,demographic and marketplace changes that are further affected by globalization. These shifts also require organizations tomaximize productivity with minimum workplace leading to reevaluation of costs associated with talent. Therefore, employeesare expected to professionally function with responsibility, new initiatives, effective time management and commitment, andthese expectations will result in employees being physically and mentally strained at their workplaces. Employee may becomeoverwhelmed outside the workplace. Employees are one of the most valuable assets of any organization. The active role they playtowards a company's success cannot be underestimated. Therefore, counseling intervention must play on employeeengagement in ABC Apparel Manufacturing Pvt Ltd. Two independent factors have been considered in this research. Theyare group counseling and individual counseling; therefore, the sole dependent variable is employee engagement. 150 employees were selected as the sample for this study. The analysis of findings revealed that there is a better relationship between groupcounseling, individual counseling and employee engagement. Counseling intervention is the most critical party in this situationto increase employee morale and, it is found that counseling intervention plays a role in enhancing employee engagement in acompany. DOI : http://doi.org/10.31357/fhss/vjhss.v06i01.11 &nbsp

Exploring Strategies for Minimizing Clinical and Medical Waste during the Covid-19 Pandemic with reference to the Colombo District, Sri Lanka

The COVID-19 pandemic seriously disrupted the waste management systems around the world and enhanced clinical and medical waste generation in most developing countries, including Sri Lanka. The present examines the upward trend in clinical waste of the Colombo District, contributed by prevailing practices, challenges, and environmental impacts stemming from poor waste management linked to the pandemic. A qualitative research methodology was adapted and, as population 63 Public and Private Hospitals in the Colombo District are included. Using purposive sampling technique nine In-Charge Officers and nine Overseers are selected as the sample. Accordingly, study sample comprising of 18 participants. Open-ended personal interviews and site visits are used as primary data collection methods. Secondary data is collected through research articles, journals, and custom department statistics, logbooks maintain by waste management department of each hospital. Studies have documented an increase in clinical waste by approximately 35% compared to the pre-pandemic era and infectious waste increased by 60%, inclusive of Personal Protective Equipment (PPE) such as masks, gloves, and gowns. Hazardous plastic waste surged 45%, partly due to single-use medical products. The majority of hospitals had conventional ways of managing the wastes, while more than 70% of facilities faced problems while adhering to guidelines pertaining to segregation at the source and waste disposal. In addition, only 30% of hospitals could show specific premises for waste treatment, as a result, up to 50% of medical waste was subjected to incineration without filtration or landfills, which increased the pollution burden. The study concludes with dire needs of practices that ensure sustainable waste management with proposals such as biodegradable personal protection equipment and reusable containers. To this end, this paper concludes that without new strategies, COVID-19 waste will leave behind a legacy that has a long-term impact on the environment. It is thus recommended that further studies in the area be carried out to expand the scope beyond the hospital’s setting by incorporating quantitative analyses that bear on improved understanding and policy. Keywords: Clinical Waste, Corona Virus, Covid-19 Pandemic, Medical Waste, Strategie

Optimal Design Construction with respect to Several Probability Distributions using Clustering Approach

Optimization has been a basic tool in most of the areas of theoretical and applied sciences. Optimal design theory focuses on identifying an experimental design that makes the variances of a model's parameter estimates as small as possible, thereby allowing the model to make the most accurate predictions. In this thesis, we have tried to address an important problem in optimal regression design, namely the application of a clustering approach to solve optimization problems with respect to several probability distributions and to further improve the convergence of a class of algorithms using the properties of directional derivatives. When we run a multiplicative algorithm to construct an optimal design, the design turns out to be a distribution de fined on a disjoint set of clusters of points. This situation arises when many design weights converge to zero at the optimum. We replace the single distribution by conditional distributions and a marginal distribution across the clusters. Motivated by this, we transform this clustering approach to a general problem of optimization with respect to several distributions. The number of probability distributions depends on the number of parameters in the model. We focus on constructing designs for two criteria of interest such as D-optimality and Ds-optimality criteria. The D-optimality is the most important and popular design criterion in the literature. The Ds-optimality is also quite important when we are interested in a subset of parameters. This situation arises when we are more interested in some of the terms (for example, the even or odd power terms) in the model. We also constructed some Ds-optimal designs using analytic approach. We explore several models both in one and two design variables. The graphical interpretation was carried out using the plots of weights versus design points as well as plots of variance functions versus design points. We did a powerful improvement in the convergence of the algorithms by combining the clustering approach and the properties of the directional derivatives. The results are promising. This approach is instrumental in improving the convergence of the algorithm and allowing the model to obtain the optimal design saving cost and time.October 202

The Influence of Mobile App Store Ratings and Reviews on Download Intentions: A Study of Sri Lankan Consumers

Purpose: This study aims to understand the impact of user reviews and ratings on mobile app download intention and the moderating impact of perceived usefulness on the strength of this relationship. Design/methodology/approach: A scenario-based survey method was selected following the positivism research paradigm. For this purpose, 304 responses were collected using different versions of the same scenario. Findings: The statistical results show that 37.5% of Sri Lankan consumers' mobile app download intention is explained by mobile app ratings and reviews, which have been found to be a significant influencing factor in potential users' intentions to download the app. However, perceived usefulness does not significantly moderate this relationship. Originality: This study is the first attempt to understand the impact of user reviews and ratings on mobile app download intention in the Sri Lankan context. Implications: The findings encourage Sri Lankan mobile app developers and owners to closely monitor and respond to user reviews and ratings to better meet user expectations and improve app ratings

COMPARATIVE STUDY OF CULTURAL CUSTOMS: CHINESE SPRING FESTIVAL AND SINHALA AND TAMIL NEW YEAR FESTIVAL

There was a gradual increase in the popularity of the Chinese language across the globe owing to China's economic and social developments. Thus, this resulted in a momentum of the teaching and learning of the Chinese language that elevated the number of Chinese language acquirers. It is obvious that culture grants a dual role in foreign language acquisition. Yet, many learners undergo obstacles in interpreting a foreign language and its cultural context by reminiscing through their native culture. On the other hand, the knowledge of the culture of the target language supports resolving misunderstandings and problems that arise within the learning context. Both learners and teachers should strive to view both the target and their native cultures from multiple perspectives, fostering an open-minded and rational understanding. In the scope of culture, festivals become a key component in every country. Therefore, this study focusses on comparing the traditional Spring festival in China with the Sri Lankan cultural festival, Sinhala and Tamil New year. The primary methodology employed in this regard is the survey method to denote a comprehensive understanding of similarities and discrepancies of these festivals. Furthermore, this study caters for three major objectives: to apply the findings of the study to Chinese language instruction, to promote cross cultural understanding between two countries and to explore the impact of technological development on festival culture.  Article visualizations