Investigation of cylinder deactivation and variable valve actuation on gasoline engine performance

Increasingly stringent regulations on gasoline engine fuel consumption and exhaust emissions require additional technology integration such as Cylinder Deactivation (CDA) and Variable valve actuation (VVA) to improve part load engine efficiency. At part load, CDA is achieved by closing the inlet and exhaust valves and shutting off the fuel supply to a selected number of cylinders. Variable valve actuation (VVA) enables the cylinder gas exchange process to be optimised for different engine speeds by changing valve opening and closing times as well as maximum valve lift. The focus of this study was the investigation of effect of the integration of the above two technologies on the performance of a gasoline engine operating at part load conditions. In this study, a 1.6 Litre in-line 4-cylinder gasoline engine is modelled on engine simulation software and simulated data is analysed to show improvements in fuel consumption, CO2 emissions, pumping losses and effects on CO and NOx emissions. A CDA and VVA operating window is identified which yields brake specific fuel consumption improvements of 10-20% against the base engine at engine speeds between 1000rpm to 3500rpm at approximately 12.5% load. Highest concentration of CO emissions was observed at between 4 to 5 bar BMEP at 4000rpm and highest concentration of NOx at the same load range but at 1000rpm.Findings based on simulation results point towards significant part load performance improvements which can be achieved by integrating cylinder deactivation and variable valve actuation on gasoline engines. Copyright © 2014 SAE International

An innovative approach to manage prosumers in smart grid

Smart Grid (SG) achieves bidirectional energy and information flow between the energy user and the utility grid, allowing energy users not only to consume energy, but also to generate the energy and share with the utility grid or with other energy consumers. This type of energy user is called the "prosumer". The sustainability of the SG energy sharing process depends on its participating prosumers. Hence the prosumer management schemes are crucial within the energy sharing field. However, the existing literature on SG energy sharing has shown little attention on prosumer participation and management. The contribution of this paper is twofold. First we critically analyze the prosumer management schemes used by existing approaches and identify the open research issues. Second, we introduce a novel concept to manage the prosumers in the form of goal oriented virtual prosumer-communities and we discuss the aspects of prosumer-community formation, growth and overall management. The main significance of this approach is that the prosumer-communities facilitate the prosumers with similar interest to join together and increase the quantity of energy to be auctioned to the SG and accordingly increase the bargaining power in the energy market. In addition, the prosumer communities can attain more sustainable energy sharing process in long-term

Social Listening Practices towards Social CRM and Customer Relationship Performance in the Fast-Food Industry in Sri Lanka

This study is carried out to identify the impact of social listening practices on social CRM and customer relationship performance in the fast-food industry in Sri Lanka. The target population for this study included the internal stakeholders from the organizations in the fast-food industry located in the Colombo metropolitan area which uses social media. The data was obtained via a structured questionnaire using a sample of 150 registered organizations. The time horizon was cross-sectional, and data were analyzed through both descriptive and inferential analysis. Based on the Resource-Based View (RBV) and the Capabilities Based Perspective, especially the dynamic capabilities theories, the conceptual model of this research study was developed by expecting that, organizations in the fast-food industry in Sri Lanka can exploit capabilities which are social listening practices and social CRM capabilities and resources which are customer relationship orientation and social media technology usage to obtain higher customer relationship performance.  Further, gain a competitive advantage over their competitors by effectively utilizing such resources. This is one of the few papers to exclusively focus on the impact of social listening practices on social CRM and customer relationship performance in the fast-food industry in Sri Lanka. The findings of this study have important implications for the fast-food industry in Sri Lanka. Keywords: Customer Relationship Management (CRM); Customer Relationship Orientation (CRO); Customer Relationship Performance; Social Customer Relationship Management (Social CRM) capabilities; Social media technology; Fast-food industr

Wireless Sensor Networks: Challenges Ahead

The aim of this paper is to analyze the different Wireless Sensor Network (WSN) transport protocols byidentifying various experimental parameters in order to undertake a comparative evaluation. To build the groundwork, we first discuss the generic design for a transport protocol based on three key concepts; congestion control, reliability support and priority support. The basis of this design was developed by assessing several aspects of numerous transport protocols. However they all using different set of parameters and settings and hence it is difficult to benchmark one against the other. In this paper, we discuss the simulation settings like packet size, number of exploited sensors and their distribution in the field, buffer size, coverage area and power levels

Wireless Sensor Network Transport Protocol - A State of the Art

In this article, we present a survey of Wireless Sensor Networks (WSNs) existing Transport Protocols. Wehave evaluated the design concepts of different protocols based on congestion control, reliability support and source traffic priority support. Then we draw the concluding remarks, while highlighting up-and-coming research challenges for WSN transport protocols, which should be addressed further in prospective designs

RLZAP: Relative Lempel-Ziv with Adaptive Pointers

Relative Lempel-Ziv (RLZ) is a popular algorithm for compressing databases of genomes from individuals of the same species when fast random access is desired. With Kuruppu et al.'s (SPIRE 2010) original implementation, a reference genome is selected and then the other genomes are greedily parsed into phrases exactly matching substrings of the reference. Deorowicz and Grabowski (Bioinformatics, 2011) pointed out that letting each phrase end with a mismatch character usually gives better compression because many of the differences between individuals' genomes are single-nucleotide substitutions. Ferrada et al. (SPIRE 2014) then pointed out that also using relative pointers and run-length compressing them usually gives even better compression. In this paper we generalize Ferrada et al.'s idea to handle well also short insertions, deletions and multi-character substitutions. We show experimentally that our generalization achieves better compression than Ferrada et al.'s implementation with comparable random-access times

Disasters and climate change in the Pacific: adaptive capacity of humanitarian response organizations

© 2014, © 2014 Taylor & Francis. Climate change is likely to affect the pattern of disasters in the Pacific and, by extension, the organizations and systems involved in disaster response. This research focused on how immediate humanitarian health-related needs following disasters are met using the concept of adaptive capacity to investigate the resilience of organizations and the robustness of the broader system of disaster response. Four case study countries (Cook Islands, Fiji, Samoa, and Vanuatu) were chosen for deeper investigation of the range of issues present in the Pacific. Key findings were that adaptive capacity was enhanced by strong informal communication and relationships as well as formal relationships, appropriate participation of traditional leaders and churches, and recognition and support for the critical role national disaster management offices play in disaster coordination. Adaptive capacity was found to be constrained by lack of clear policies for requesting international assistance, lack of coordinated disaster assessments, and limited human resources for health in disaster response. Limitations in psychosocial support and Australian medical services to meet specific needs were observed. Finally, the research revealed that both Pacific and Australian disaster-response agencies would benefit from a strengthened ‘future’ focus to better plan for uncertainty and changing risks

Suffix Tree of Alignment: An Efficient Index for Similar Data

We consider an index data structure for similar strings. The generalized suffix tree can be a solution for this. The generalized suffix tree of two strings $A$ and $B$ is a compacted trie representing all suffixes in $A$ and $B$. It has $|A|+|B|$ leaves and can be constructed in $O(|A|+|B|)$ time. However, if the two strings are similar, the generalized suffix tree is not efficient because it does not exploit the similarity which is usually represented as an alignment of $A$ and $B$. In this paper we propose a space/time-efficient suffix tree of alignment which wisely exploits the similarity in an alignment. Our suffix tree for an alignment of $A$ and $B$ has $|A| + l_d + l_1$ leaves where $l_d$ is the sum of the lengths of all parts of $B$ different from $A$ and $l_1$ is the sum of the lengths of some common parts of $A$ and $B$. We did not compromise the pattern search to reduce the space. Our suffix tree can be searched for a pattern $P$ in $O(|P|+occ)$ time where $occ$ is the number of occurrences of $P$ in $A$ and $B$. We also present an efficient algorithm to construct the suffix tree of alignment. When the suffix tree is constructed from scratch, the algorithm requires $O(|A| + l_d + l_1 + l_2)$ time where $l_2$ is the sum of the lengths of other common substrings of $A$ and $B$. When the suffix tree of $A$ is already given, it requires $O(l_d + l_1 + l_2)$ time.Comment: 12 page

Practices Followed to Manage Plastic Waste including Shopping Bags and Lunch Sheets in Sri Lanka: A Preliminary Study in Western Province

Although plastics have made the workings of our lives easier, it has created many different environmental and social problems due to poor management practices. The problem of plastic waste has been exacerbated due to various regulations that have been introduced from time to time for the sustainable management of plastic waste. However, those are not properly implemented. The main objective of this study is to examine the best practices in Sri Lanka for the management of plastic waste, including shopping bags and lunch sheets (PBLS). Further, the study illustrated the prevailing and possible alternatives for polythene products in Sri Lanka and weaknesses in the identification of alternatives. The study was conducted in the Western Province covering three districts: Colombo, Gampaha and Kalutara. Data collection was conducted through different structured questionnaire surveys, key informant interviews and a major workshop from a sample of 1314 respondents. Results revealed that 59% of households in the survey confirm that they were discouraged from switching to alternatives as a result of freely available low-density polyethylene (LDPE) bags in the market. Also, 67% of the households and 74% of the supermarkets pointed out that, the current polythene bag usage was higher prior to the ban, due to the poor strength and quality of the bag. Further, the study reveals that ‘Extended Producer Responsibility (EPR)’ has the potential to influence material management systems and prevent pollution and has been successfully tested in many countries around the world. DOI: http://doi.org/10.31357/fhss/vjhss.v07i01.0