PSD Estimation of Multiple Sound Sources in a Reverberant Room Using a Spherical Microphone Array

We propose an efficient method to estimate source power spectral densities (PSDs) in a multi-source reverberant environment using a spherical microphone array. The proposed method utilizes the spatial correlation between the spherical harmonics (SH) coefficients of a sound field to estimate source PSDs. The use of the spatial cross-correlation of the SH coefficients allows us to employ the method in an environment with a higher number of sources compared to conventional methods. Furthermore, the orthogonality property of the SH basis functions saves the effort of designing specific beampatterns of a conventional beamformer-based method. We evaluate the performance of the algorithm with different number of sources in practical reverberant and non-reverberant rooms. We also demonstrate an application of the method by separating source signals using a conventional beamformer and a Wiener post-filter designed from the estimated PSDs.Comment: Accepted for WASPAA 201

Development of a framework for quality assurance of off-site manufactured building components: A case study of the New Zealand housing sector

A shortage of housing is a prominent issue across the globe. Traditional on-site construction methods seem too inefficient to meet the increasing housing demand. As a solution, many countries, including the United States, Germany, Singapore, Japan, Hong Kong and Australia, have introduced off-site manufacturing methods to increase the housing supply. Different from the traditional way of on-site construction, off-site manufacturing is a technique that involves manufacturing building components in a controlled environment. Despite strong government support and industry attempts to increase off-site manufacturing, the current building consenting and inspection processes in New Zealand have significant quality-related issues. Therefore, this study aimed to identify the gaps in current quality assurance processes used in off-site manufacturing and recommend a framework in order to gain credibility and the acceptance of the construction market. The study collected qualitative data from industry experts (e.g., developers, architects, engineers, project managers, quantity surveyors, head contractors and council officers) who had significant experience in current quality assurance regimes in New Zealand prefabrication construction. The key themes for designing the proposed framework were generated using content analysis of the primary data collected from semi-structured interviews with industry experts. The study has found that standardisation in off-shore products regarding the New Zealand Building Code remains the biggest challenge in the consenting process. Quality assurance and inspection test plans are the developer's responsibility and are typically provided by third-party inspectors. In this post-Covid-19 world-building, consent authorities rely heavily on third-party inspection companies that apply more rigorous auditing. Essentially, the most important parts of quality assurance are to have an experienced team and to adopt a holistic approach by engaging stakeholders early in the design stage. The stakeholders should consider recommendations for mandatory after-service insurance to ensure end-customer interests are protected. The findings of this study can contribute to the early engagement of different stakeholders to ensure overseas manufacturing of building components meets New Zealand quality standards. It is expected that the new quality assurance framework would help to promote off-site manufacturing for the New Zealand housing sector.fals

What drives Success of Learning Management Systems in Sri Lanka: Student Perspective

Developments in Information technology has made rapid changes in the traditional teaching and learning methods in organizations, such as higher education institutions. This new method of teaching and learning is enabled mainly through Learning Management Systems. Issues in effective implementation and management of such systems have drawn the attention of many researchers. However, LMS success research still lacks particularly in the Sri Lankan higher education context. Hence, the purpose of this research was to examine the success of e-Learning systems in the Sri Lankan higher education context. The conceptual model was tested by fitting it to data collected from undergraduate students using learning management systems. This was the first study to test a multidimensional e-Learning systems success model (DeLone and McLean’s, 2003, IS success model) in the Sri Lankan context. Of the quality dimensions considered, quality of the information/content provided by the system was the most influential. Student satisfaction had the largest effect size on benefits to students. This study provides meaningful insights particularly relevant to e-Learning implementers in higher education in Sri Lanka

PSD Estimation and Source Separation in a Noisy Reverberant Environment using a Spherical Microphone Array

In this paper, we propose an efficient technique for estimating individual power spectral density (PSD) components, i.e., PSD of each desired sound source as well as of noise and reverberation, in a multi-source reverberant sound scene with coherent background noise. We formulate the problem in the spherical harmonics domain to take the advantage of the inherent orthogonality of the spherical harmonics basis functions and extract the PSD components from the cross-correlation between the different sound field modes. We also investigate an implementation issue that occurs at the nulls of the Bessel functions and offer an engineering solution. The performance evaluation takes place in a practical environment with a commercial microphone array in order to measure the robustness of the proposed algorithm against all the deviations incurred in practice. We also exhibit an application of the proposed PSD estimator through a source septation algorithm and compare the performance with a contemporary method in terms of different objective measures

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

Green intraprenurial flexibility towards sustaining competitive advantage: A case of South Asian context

This study explores how green based intrapreneurial flexibility affects sustainable business performance of the Sri Lankan hotel industry. A survey was administered to a random sample of senior managers of hotels in Sri Lanka. Linear regression analysis revealed a significant path coefficient which explained green based intrapreneurial flexibility positively influenced sustainable competitive advantage. The findings suggest that hotel industry policy makers develop green specific intrapreneurial capabilities so that they can quickly adapt their green based product and service offerings in responding to changes of the green market requirements by focusing on green based new venture creation, green innovation, green related self-renewal exercises, and eco-friendly proactive decision making in order to sustain their competitive advantage from green initiatives