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

Drug policy-making in Sri Lanka 1984-2008: people, politics and power

Policy analysis has not been a part of mainstream Sri Lankan research or academic tradition, and hence there exists a lack of research on policy studies in Sri Lanka. Given also a paucity of research on illicit drug use and contemporary drug policy, this research study generated and analysed a body of evidence about the response to drug misuse and its related policies in Sri Lanka between 1984 and 2008. As the subject of drug policy can be viewed through a variety of perspectives, this thesis adopted a multi-disciplinary approach. It drew on ideas, theories, concepts and research from a variety of social science disciplines such as sociology, political science, international relations, public administration and social policy and included an historical approach to understanding policy development. The study provides an informed narrative describing the rationale for the development of Sri Lanka’s drug policies, their course and outcome and the roles of the various actors, institutions, organisations and interest groups already established, or which came into existence to respond to drug misuse. This shows how, and why, particular policies are shaped and influenced by the actors, institutions and organisations, and by particular discourses. The conceptual foundations for this study were epistemic community theory, stakeholder analysis and policy transfer theory; and the thesis will seek to explain policy in changing contexts. Semi-structured key informant interviews and documentary analysis were the main research methods employed. The analysis revealed that external influences, stakeholder dynamics, consensus in policy approaches, and moral frameworks have combined to sustain a criminal justice model to the management of drug problems and to ward off attempts to introduce a system with a stronger focus on treatment and public health. This study demonstrates that the interests of stakeholders and their relative power significantly influenced the legitimisation of consensual knowledge diffused by epistemic communities which underpinned policy outcomes

Customer Behavior Analysis for Social Media

It is essential for a business organization to get the customer feedback in order to grow as a company. Business organizations are collecting customer feedback using various methods. But the question is ‘are they efficient and effective?' In the current context, there is more of a customer oriented market and all the business organizations are competing to achieve customer delight through their products and services. Social Media plays a huge role in one's life. Customers tend to reveal their true opinion about certain brands on social media rather than giving routine feedback to the producers or sellers. Because of this reason, it is identified that social media can be used as a tool to analyze customer behavior. If relevant data can be gathered from the customers' social media feeds and if these data are analyzed properly, a clear idea to the companies what customers really think about their brand can be provided

Generation of Functional CLL-Specific Cord Blood CTL Using CD40-Ligated CLL APC

PMCID: PMC3526610This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Book Review: A Guide to Academic Writing and Research Reports by Senior Prof. Dr. Mangala Fonseka and Dr. Athula Manawaduge

Scholarly or academic writing is clear, concise, planned, coherent, and backedup by evidence. Its purpose is to aid the reader’s understanding. Hence, itconsists of a formal style and tone. Further, it does not require the use of longsentences and instead uses clear and concise language with simple vocabulary.Research report writing is an integral part of academic writing. Hence, bothacademic and research report writing play a vital role in developing a multitudeof researchers across the globe. The authors of the book entitled “A Guide toAcademic Writing and Research Reports” identified such a role to developprolific researchers amongst the student community both within and outside theuniversity in Sri Lanka

Morbidity Pattern in End Stage Renal Disease Patients Before And After Renal Transplantation

Introduction: To effectively and efficiently plan programmes for prevention and control of End Stage Renal Disease (ESRD)/ chronic kidney disease, there is a need for basic epidemiological and clinical data. This hospital-based descriptive study on renal transplant patients attempted to provide some information on their morbidity pattern before and after renal transplantation. Methods: A hospital-based study was conducted at the Teaching Hospital, Kandy. The study sample consisted of 305 patients who had undergone real transplant and attended the clinic during the three month period of data collection. Interviewer administered questionnaire was used as the data collection tool. Results: Renal transplant patients are prone to infections mainly due to iatrogenic immunosuppression. Cytomegalovirus infection was the commonest. Other common infections observed were upper respiratory tract infections, gastroenteritis and urinary tract infections. All the patients who participated in the study developed at least one non-communicable disease during the follow up period. Anaemia (54%) was the most common problem encountered, followed by rejection, both acute and chronic (50%) and dyslipidaemia (44%). Almost all the participants had hypertension developed before or after the transplantation. This suggests that hypertension is leading to ESRD, resulting from ESRD or just a co-morbidity. Conclusion: Cytomegalovirus infection was the commonest infectious disease reported. Other common infections observed in this study were upper respiratory tract infections, gastroenteritis and urinary tract infections. All the patients developed at least one non-communicable disease during the follow up period. Key words: Morbidity, Renal Transplant, Non Communicable Diseas

Aetiological Factors Associated With End Stage Renal Disease; Analysis of End Stage Renal Patients in Sri Lanka

Introduction: End stage renal disease (ESRD) can be considered as one of the growing health problems as well as a public health issue in Sri Lanka. The demographic and epidemiological transition currently the country undergoes, contribute significantly to this problem. Methods: This study was conducted at the Nephrology Clinic, Kandy Teaching Hospital, a tertiary level medical institution. The study sample consisted of renal transplant patients satisfied the selection criteria. Considering the estimated sample size, no sampling techniques were used and a total of 305 patients interviewed using the study instrument, an interviewer-administered questionnaire. Results: Investigation of possible aetiology of ESRD revealed that for 69.5% cases aetiology was not well established. Among the known aetiological factors, diabetes (38%) was the commonest followed by nephrotic syndrome (19%) and hypertension (18%). This distribution pattern differs from what was observed in other countries. The differences in the aetiology of ESRD in regard to sex of patients, ethnicity, educational status, occupation and income were statistically not significant. Conclusion: Investigation of possible aetiology of ESRD revealed that for 69.5% cases aetiology was not well established. Among the known aetiological factors, diabetes (38%) was the commonest followed by nephrotic syndrome (19%) and hypertension (18%). The differences in the aetiology of ESRD in regard to sex of patients, ethnicity, educational status and occupation were statistically not significant. Key words: End Stage Renal Disease, Aetiological factors, Non Communicable Diseas