Corporate Mandatory and Voluntary Disclosure Practices in Bangladesh: Evidence from listed companies of Dhaka Stock Exchange

This paper investigates the extent and level of mandatory and voluntary disclosure practice of companies in Bangladesh. The paper has been conducted on the sample of 54 listed companies in Bangladesh for a data period of 2010 to 2013. This paper also reports the results of the association between company specific characteristics and mandatory as well as voluntary disclosure of the sample companies. Findings indicate on an average 71% of the companies analyzed disclose above-average number of additional information. The explanatory analyses has shown that firm size in terms of total asset and status of the company significantly and positively affect the level and extent of voluntary disclosure in the annual report of Bangladeshi companies. In case of mandatory disclosure level results point out that companies in general have not reacted adequately to the mandatory disclosure requirements of the regulatory bodies. The study reveals that disclosure compliance is poor among listed companies. They disclosed an average of 50.62% of the items selected during the study period of 2010 to 2013. The minimum score found in the study is 20.89% and the maximum is 77.08%. Using panel data regression analysis this study has found that company age and the status of the company (industry type) have appeared to be significant factors for mandatory disclosure. On the other hand company size in terms of total asset and sales, and company profitability was also found to have no effect on mandatory disclosure. Keywords: Mandatory disclosure, Voluntary disclosure, Disclosure index, Bangladeshi companies, Corporate Governance

AlGaN/GaN HEMTにおける電流コラプスの機構と抑制

An AlGaN/GaN-based high-electron-mobility transistor (HEMT) is considered as an excellent candidate for future power devices due to its high breakdown voltage, high saturation drain current and low on-resistance (Ron). However, current collapse, i.e., dispersion of drain current or increased dynamic Ron, is regarded as one of the most critical issues to be solved for actual power-switching applications. Even though there have been remarkable improvements in growth and device technologies, it is still essential to understand mechanism of current collapse and ways to get rid of it. In this work, I have investigated the effect of passivation on current collapse in AlGaN/GaN HEMTs. A detailed analysis on trapping effects and localization of traps has been made. In order to suppress current collapse in AlGaN/GaN HEMTs, field plate (FP) structured devices have been studied. Drain current dispersion measurements have been performed for AlGaN/GaN HEMTs having different passivation films such as SiN and Al2O3. Passivated devices exhibited dispersion between static and pulsed current-voltage characteristics. The maximum drain current for SiN passivated devices was improved by around 25% at pulsed measurements as compared to its static value, whereas Al2O3 passivated devices exhibited that of around 56% deterioration. The drain current was decreased with increasing on-state duration time for SiN passivated devices, while it was increased for Al2O3 passivated devices. The mechanism responsible for the increase of drain current with on-state duration time by AlGaN surface traps is proposed, while GaN buffer traps reasonably govern the decrease of drain current. Effects of SiN passivation on current collapse have been studied by monitoring the dynamic change in Ron. The normalized dynamic Ron was decreased with increasing SiN-deposition temperature and became high with increasing off-state drain bias voltages. The normalized dynamic Ron was also decreased with increasing annealing temperature. These results indicate that the SiN/AlGaN interface trap density is reduced with increasing both SiN-deposition and annealing temperatures. Current collapse measurements have been performed for AlGaN/GaN HEMTs having identical breakdown voltages but with different FP lengths. The results indicated that applying more positive on-state gate biases resulted in pronounced recovery in the dynamic Ron for the FP device, whereas no gate-bias effects were observed for the device without FP. The mechanism responsible for the reduced current collapse by FP is proposed, in which the key role is played during on-state by the quick field-effect recovery of partial channel depletion caused by electron trapping at AlGaN surface states between gate and drain. The above studies indicate that the current collapse is suppressed by good passivation film and longer FP with more positive on-state gate biases in AlGaN/GaN HEMTs for future high-power applications

Prevalence of musculoskeletal disorders in elderly population in a rural community of Bangladesh

Background: Musculoskeletal disorders are a leading source of physical impairment in elderly, and the frequency of these disorders is anticipated to increase rapidly as the population ages. In Bangladesh, musculoskeletal disorders among the elderly are on the rise, causing them immense misery. The aim of this study to find out prevalence of musculoskeletal disorder in this age group in a rural community of Bangladesh. Methods: A descriptive cross-sectional study was conducted over the period of one year from April 2017 to March 2018 in a few villages of Mokshedpur union of Dohar Upazila in Dhaka district of individuals with 60 and above. Modified COPCORD (Community Oriented Program for Control of Rheumatic Disorders) questionnaire was used to detect positive respondents. Results: The prevalence of musculoskeletal pain was 52.10%. Prevalence was higher in women, 113 (56.6%) than men, 85 (43.4%). Most of the patient belongs to age group 60-69 (79.3%). Higher prevalence rates were observed in housewife (42%), retired person (24%) and cultivators (17%). Most of the individual had no smoking habit, 145 (73.2) and 42.9% are daily smokeless tobacco users. Lower back pain (42.4%) and knee pain (37.4%) were prevalent among the study group. Non-specific low back pain (28.8%) and osteoarthritis in the knee (26.3%) were prevalent among the study group. Among all the disorder, female is prevalent than male. Conclusions: Musculoskeletal disorders are common causes of morbidity and disability in rural communities of Bangladesh. Women are affected more frequently than men. Mechanical disorders are more common than inflammatory arthropathies

Optimal Planning of Standalone Solar-Wind-Diesel Hybrid Energy System for a Coastal Area of Bangladesh

For sustainable development of a country access to electricity in every moment is now the basic need for the current civilization. Power crisis is one of the major barriers for economic development of Bangladesh. Bangladesh lacks in fossil fuel reservation. Abundance of renewable energy sources in the form of solar energy, wind energy provides opportunities of renewable energy based hybrid energy system in the coastal areas of Bnagladesh. Energy generation by hybrid system reduces the generation cost and will help in balancing the cost of energy. Again a standalone renewable enegy incorporated hybrid energy system will reduce load demand from the grid and will be an eco-friendly energy system. This paper proposed a cost effective design of standalone solar-wind-diesel hybrid power system in a coastal area of Bangladesh. Considering different conditions for a coastal area design and simulation of the hybrid power system was performed. Detailed economic analysis and comparison with solar based and diesel based energy system clearly reveals that proposed hybrid power system was found a cost effective solution for coastal areas of bangladesh.DOI:http://dx.doi.org/10.11591/ijece.v2i6.83

An Implementation Approach and Performance Analysis of Image Sensor Based Multilateral Indoor Localization and Navigation System

Optical camera communication (OCC) exhibits considerable importance nowadays in various indoor camera based services such as smart home and robot-based automation. An android smart phone camera that is mounted on a mobile robot (MR) offers a uniform communication distance when the camera remains at the same level that can reduce the communication error rate. Indoor mobile robot navigation (MRN) is considered to be a promising OCC application in which the white light emitting diodes (LEDs) and an MR camera are used as transmitters and receiver respectively. Positioning is a key issue in MRN systems in terms of accuracy, data rate, and distance. We propose an indoor navigation and positioning combined algorithm and further evaluate its performance. An android application is developed to support data acquisition from multiple simultaneous transmitter links. Experimentally, we received data from four links which are required to ensure a higher positioning accuracy

A New Vehicle Localization Scheme Based on Combined Optical Camera Communication and Photogrammetry

The demand for autonomous vehicles is increasing gradually owing to their enormous potential benefits. However, several challenges, such as vehicle localization, are involved in the development of autonomous vehicles. A simple and secure algorithm for vehicle positioning is proposed herein without massively modifying the existing transportation infrastructure. For vehicle localization, vehicles on the road are classified into two categories: host vehicles (HVs) are the ones used to estimate other vehicles' positions and forwarding vehicles (FVs) are the ones that move in front of the HVs. The FV transmits modulated data from the tail (or back) light, and the camera of the HV receives that signal using optical camera communication (OCC). In addition, the streetlight (SL) data are considered to ensure the position accuracy of the HV. Determining the HV position minimizes the relative position variation between the HV and FV. Using photogrammetry, the distance between FV or SL and the camera of the HV is calculated by measuring the occupied image area on the image sensor. Comparing the change in distance between HV and SLs with the change in distance between HV and FV, the positions of FVs are determined. The performance of the proposed technique is analyzed, and the results indicate a significant improvement in performance. The experimental distance measurement validated the feasibility of the proposed scheme

Building Pattern Technique of an Indigenous Community – Does Its Appearances a Distinctive Representation?

Bangladesh is enriched with beautiful traditional indigenous cultures. Different indigenous peoples with their distinctive existences also considerably create an enhance values and lifestyles to the socio-cultural sectors of Bangladesh [1]. Habitually, these indigenous communities have been comparable to live a large combined family to shear their lifestyles [2]. Presently the country has 45 indigenous communities who are living in different locations. All indigenous people within this country have their own style to build their settlements with special techniques to keep them safe and sound from all types of natural and environmental vulnerabilities and also enhance their knowledge of construction techniques and lifestyle. Rakhain is one of them with very small number of people are still living in different regions within the country which have their own system of building techniques. Study found that for several hundreds of years Rakhains are strictly following their indigenous prescription of house and settlement pattern. Although like other indigenous people of this country, they have mountains of problems, such as forced land occupation, lack of security and minority characteristics. Above all, forced political separation has gradually drowned them in the abysmal pit of marginal destiny. This has turned them into exiles in their own land. As a result, many of them are being forced to leave the country and as a result they misplaced their native knowledge and technique to construct. Thus, this study will initially focus on to search for the distinctiveness of their settlement pattern and building construction techniques and lifestyle. Again, in view of their problems, knowledge and experiences concerning archetype, built and house pattern, this study will finally explain how Rakhains accumulate their every distinctiveness from history and for present and future invention

Biofilm Formation, Production of Matrix Compounds and Biosorption of Copper, Nickel and Lead by Different Bacterial Strains

Bacterial biofilms play a key role in metal biosorption from wastewater. Recently, Enterobacter asburiae ENSD102, Enterobacter ludwigii ENSH201, Vitreoscilla sp. ENSG301, Acinetobacter lwoffii ENSG302, and Bacillus thuringiensis ENSW401 were shown to form air–liquid (AL) and solid–air–liquid (SAL) biofilms in a static condition at 28 and 37°C, respectively. However, how environmental and nutritional conditions affect biofilm formation; production of curli and cellulose; and biosorption of copper (Cu), nickel (Ni), and lead (Pb) by these bacteria have not been studied yet. In this study, E. asburiae ENSD102, E. ludwigii ENSH201, and B. thuringiensis ENSW401 developed the SAL biofilms at pH 8, while E. asburiae ENSD102 and Vitreoscilla sp. ENSG301 constructed the SAL biofilms at pH 4. However, all these strains produced AL biofilms at pH 7. In high osmolarity and ½-strength media, all these bacteria built fragile AL biofilms, while none of these strains generated the biofilms in anaerobic conditions. Congo red binding results showed that both environmental cues and bacterial strains played a vital role in curli and cellulose production. Calcofluor binding and spectrophotometric results revealed that all these bacterial strains produced significantly lesser amounts of cellulose at 37°C, pH 8, and in high osmotic conditions as compared to the regular media, at 28°C, and pH 7. Metal biosorption was drastically reduced in these bacteria at 37°C than at 28°C. Only Vitreoscilla sp. ENSG301 and B. thuringiensis ENSW401 completely removed (100%) Cu and Ni at an initial concentration of 12.5 mg l–1, while all these bacteria totally removed (100%) Pb at concentrations of 12.5 and 25 mg l–1 at pH 7 and 28°C. At an initial concentration of 100 mg l–1, the removal of Cu (92.5 to 97.8%) and Pb (89.3 to 98.3%) was the highest at pH 6, while it was higher (84.7 to 93.9%) for Ni at pH 7. Fourier transform infrared spectroscopy results showed metal-unloaded biomass biofilms contained amino, hydroxyl, carboxyl, carbonyl, and phosphate groups. The peak positions of these groups were shifted responding to Cu, Ni, and Pb, suggesting biosorption of metals. Thus, these bacterial strains could be utilized to remove Cu, Ni, and Pb from aquatic environment