Object search and retrieval in indoor environment using a Mobile Manipulator

Robots are increasingly viewed as service agents in offices and homes. In many countries where the average population is aging, robots can be used for elderly care. This Thesis explores one such possibility using a mobile manipulator robot. Such robots have a mobile base to move from one place to another and an arm to pick and place objects. This Thesis considers a problem where the mobile manipulator needs to search for an object in an environment and bring it to some location. The optimal object search is formulated in terms of the popular traveling salesman problem (TSP) that computes the optimal sequence in which the Robot can visit all the possible locations where the object can possibly be. Prior information about the more likely locations is brought in by scaling the edge-weight of the TSP graph through the probabilities of the location. The Thesis can combine the output of TSP with navigation and manipulation planning built on top of Robot Operating Systems (ROS) to build the complete object search and retrieval pipeline. The results of the Thesis are validated both in simulation and actual hardware experiments

Corporate Board Attributes and Firm Performance of Publicly Traded Manufacturing Companies in Bangladesh

The study examines the effects of corporate board attributes on firm financial performance of publicly traded manufacturing companies in Bangladesh in the light of ‘comply or explain’ based on Corporate Governance Notifications (CGN) 2006 and ‘mandatory’ CGN 2012 of Bangladesh Securities and Exchange Commission (BSEC). BSEC makes the CGN mandatory in 2012 to ensure good governance at firm level. The regression results show that the revised CG guidelines are not capable of influencing firm performance measured by ROA but when performance is measured using Tobin’s Q, the revised guidelines are somewhat effective. We did not find any prior study in corporate governance literature that focuses on the effects of revised CGN 2012 on firm performance. This study is a pioneering research and it has led to an academic debate on the effectiveness of mandatory CG guidelines on corporate attributes and hence firm performance. Keywords: Corporate Board Attributes, Firm Performance, Corporate Governance DOI: 10.7176/RJFA/10-16-12 Publication date: August 31st 201

Subnational democracy and journalist repression: Increased violence against journalists in democratic Mexico

Existing theories of democracy and repression expect higher repression in unconsolidated democracies like Mexico. This project examines whether executive constraint, executive competition, or both, or neither matters in reducing journalist repression. I theorize that increased political competition at the local level created an open environment for journalists in Mexico, and that opening made journalists more active in covering critical news. As this critical media role also challenges the authority, and the local authorities are still not constrained sufficiently, local-level governments use repression against threatening journalists. The study expects that increasing competitiveness should have a large and positive relationship with journalist repression at low levels of executive constraint. Conversely, when the executive constraint is high, the effect of competition on repression should be smaller. By employing a comparative case study of the Mexican states, the study partially finds support for the theory. The findings show that most killings are concentrated in high executive constraint and high competition, and more competition leads to more killings given the same amount of constraints. No killings in low constraints, regardless of competitiveness. Finally, No killing in the low constraint states, and all the killings in the high competition. Competition does appear to be a driver of journalist repression, while constraints in the form of divided government do not appear to restrain repression. This surprising result may be partially explained by the high level of organized crime in some Mexican states, as additional data analyzed here suggests. The study also seems to support the “More Murder in the Middle” (e.g., Fein, 1995) hypothesis. I also studied four case studies to complement the major findings. Protection not being assigned or withdrawn before the killing, questionable practice of investigation, or cases being buried implies the state government’s involvement in the killings and that executive constraints are not enough to protect journalists. The study suggests that executive constraints matter more than the executive competition in reducing violence against journalists in newly democratized countries. The study also suggests that political competition without sufficient constraints in higher but unconsolidated democracies is dangerous for the safety of journalists

Metabolic alterations in liver of fresh water fish, C. punctata exposed to arsenic: an adverse and adaptive response to the environment

Arsenic is a major toxicant impairing in diverse metabolic alterations of the organisms and the mechanism of adaptive response is yet to be identified. In the present study, effects of different doses of arsenic in liver of Channa punctata on the regulation of metabolic activities were done. C. punctata, a variety of fresh water fish were exposed to 1, 10 and 1000 ?M concentration of Na2HAsO4 for 1 h. The amount of protein, in response to 1, 10 and 1000 ?M concentration of arsenic were augmented by 184.47% (2.84-folds), 202.82% (3.0- folds) and 317.49% (4.17-folds), respectively and was found to be higher for 1000 ?M dose. Cholesterol contents in liver were similarly exaggerated by 517.45% (6.17-folds), 308.13% (4.1-folds) and 286.41% (3.86-folds), respectively. However, the higher response was found for 1 ?M dose of Na2HAsO4. Similar stimulatory effects on triglyceride level were observed in response to arsenic. Na2HAsO4 causes 443.74% (5.43-folds), 533.11% (6.33-folds) and 548.48% (6.48-folds) enhanced triglyceride level in liver respectively and the effects were pronounced for 1000 ?M concentration. Our findings conclude that arsenic is involved in impairment of metabolic activities in liver of the species of fish and gives an impact to the environment for survival.Int. J. Agril. Res. Innov. & Tech. 6 (2): 87-94, December, 201

Analysis of Crosstalk Noise for 2π RC Model considering Interconnect Parameters in Deep Submicron VLSI Circuit

As the technology enters into deep sub-micron region, signal integrity is becoming a very crucial parameter. In order to deal with the challenges associated with signal integrity problem, such as, crosstalk noise and delay, estimation and minimizing techniques should be addressed with great importance. Along with this, the peak noise amplitude and noise width values in the sensitive node must be verified and confirmed that they are below the certain threshold levels. Hence, for a particular range of frequency, an accurate and efficient crosstalk noise estimation model is necessary to confirm the signal integrity. Therefore, this work aims to analyse the crosstalk noise between two interconnect lines using 2π RC model, and considering its physical parameters, such as the parasitic capacitance, resistance and inductance and interconnect parameters, specifically the spacing between two interconnects, length, width, thickness, height from substrate in deep sub-micron VLSI circuit. In this paper, analytical expressions for peak noise amplitude and noise width in 2π model with RC interconnects for unit step input were derived, and then it was simulated in MATLAB and HSPICE software platform. The MATLAB based results represent that 2π model possesses less errors, and showed better performance compared to some other popular models by adjusting the interconnecting parameters for any certain range of operating frequency. The HSPICE simulation justifies the accuracy of the approach with full satisfaction

Interactions between the oomycete Pythium arrhenomanes and the rice root-knot nematode Meloidogyne graminicola in aerobic Asian rice varieties

Background: Aerobic rice fields are frequently infested by pathogenic oomycetes (Pythium spp.) and the rice root-knot nematode Meloidogyne graminicola. Here, the interaction between Pythium arrhenomanes and Meloidogyne graminicola was studied in rice roots of two aerobic rice varieties. In different experimental set-ups and infection regimes, plant growth, rice yield, Pythium colonization, as well as establishment, development and reproduction of M. graminicola were studied. Results: In this study, it is shown that the presence of P. arrhenomanes delays the establishment, development and reproduction of M. graminicola compared to single nematode infected plants. The delay in establishment and development of M. graminicola becomes stronger with higher P. arrhenomanes infection pressure. Conclusions: Our data indicate that P. arrhenomanes antagonizes M. graminicola in the rice root and that the plant benefits from this antagonism as shown by the yield data, especially when either of the pathogens is present in high levels

Board Independence and Firm Financial Performance: Context of Publicly Traded Manufacturing Companies in Bangladesh

This study strives to investigate the effects of board independence on financial performance of publicly held manufacturing companies in Bangladesh using both accounting (ROA) and market-based (Tobin’s Q) performance measures. Initially, we select 150 manufacturing companies but only 85 companies remain in the study sample after fulfilling the data availability criteria over a period from 2006-2017.  The OLS regression model reveals that board independence has positive effects on both ROA and Tobin’s Q, which supports some prior studies (Pearce& Zahra, 1991; Zahra & Pearce, 1989; Ezzamel&Watson, 1993; Hossain, Prevost &Roa, 2001; Choi, Park &Yoo, 2007; Joh& Jung, 2012), but the relationship between board independence and Tobin’s Q are not statistically significant. Bangladesh Securities and Exchange Commission (BSEC) has made it a mandatory requirement in the corporate governance guidelines to include1/5th of the total directors as independent directors  into corporate boards for bringing transparency and accountability of its affairs without considering the underlying institutional differences. Though board independence is considered as an important mechanism of corporate board practices in most of the developed economies, it is still less appealing in emerging economies, especially in Bangladesh. Keywords: Independent directors; firm performance; effective function. DOI: 10.7176/EJBM/11-33-11 Publication date: November 30th 201

Evaluation of metabarcoding primers for analysis of soil nematode communities

While recent advances in next-generation sequencing technologies have accelerated research in microbial ecology, the application of high throughput approaches to study the ecology of nematodes remains unresolved due to several issues, e.g., whether to include an initial nematode extraction step or not, the lack of consensus on the best performing primer combination, and the absence of a curated nematode reference database. The objective of this method development study was to compare different primer sets to identify the most suitable primer set for the metabarcoding of nematodes without initial nematode extraction. We tested four primer sets for amplicon sequencing: JB3/JB5 (mitochondrial, I3-M11 partition of COI gene), SSU_04F/SSU_22R (18S rRNA, V1-V2 regions), and Nemf/18Sr2b (18S rRNA, V6-V8 regions) from earlier studies, as well as MMSF/MMSR (18S rRNA, V4-V5 regions), a newly developed primer set. We used DNA from 22 nematode taxa, 10 mock communities, 20 soil samples, 4 root samples, and one bulk soil. We amplified the target regions from the DNA samples with the four different primer combinations and sequenced the amplicons on an Illumina MiSeq sequencing platform. We found that the Nemf/18Sr2b primer set was superior for detecting soil nematodes compared to the other primer sets based on our sequencing results and on the annotation of our sequence reads at the genus and species ranks. This primer set generated 74% reads of Nematoda origin in the soil samples. Additionally, this primer set did well with the mock communities, detecting all the included specimens. It also worked better in the root samples than the other primer set that was tested. Therefore, we suggest that the Nemf/18Sr2b primer set could be used to study rhizosphere soil and root associated nematodes, and this can be done without an initial nematode extraction step

Rescheduling of wet season (T. Aman) rice planting for cropping intensification in coastal Bangladesh

About 1.0 million ha coastal lands in Bangladesh are mono-cropped suffer from varying degree of soil salinity, waterlogging and climate vulnerability. Low yielding, traditional T. Aman rice is grown only in wet season. Growing non-rice crop after late harvested T. Aman rice is not profitable. This study was aimed to introduce high yielding, short duration T. Aman rice varieties for advancing its harvesting time and to make the avenue for timely establishment of dry season crops. Varietal trials were made at Dacope and Amtali under ACIAR funded project during 2016-2018 and compared with local cultivars. Among tested varieties BRRI dhan76 followed by BRRI dhan77 and BRRI dhan54 in Dacope and BRRI dhan77 followed by BRRI dhan76 and BRRI dhan54 in Amtali were preferred for 0.5–1.0 tha−1 yield advantage and 15–25 days earliness compared to traditional varieties. Early harvesting of T. Aman created the avenue of timely establishment of rice and non-rice crops depending on availability of fresh water and thus crop intensification and land productivity was improved. The new cropping system increased annual rice yield and farmers’ profits by 1.5- to 2-folds compared with traditional system without environmental degradation. This technique can be replicated in similar coastal zones of Bangladesh

Utilization of sewage sludge molten slag as aggregate substitute in asphalt mixtures

Sewage sludge is one of the final products from wastewater treatment processes. Handling and disposal of sewage sludge has become one of the major economic and environmental concerns. Instead of simply treating and disposing, high temperature melting treatment is considered as one of the effective alternative efforts to utilize sewage sludge as reusable materials. High temperature melting is defined as the method of melting sewage sludge at temperature of about 1500°C before cooling the molten sludge to become solidified materials, known as molten slag. Past studies have shown that high temperature melting treatment could convert sewage sludge into reusable products without adverse environmental effects. The objective of this study is to evaluate the possible utilization of sewage sludge molten slag as aggregate substitute in asphalt mixtures for pavement construction applications. The whole concept of this study was designed to assess the materials characteristics and suitability, and thus to evaluate the performance of asphalt mixtures with sewage sludge molten slag as aggregate substitute in terms of Marshall stability and flow tests. Based on the conducted study, it can be concluded that sewage sludge molten slag fulfilled almost all the standard requirements for aggregates in asphalt mixtures and can be utilized as partial replacement for aggregates. Sewage sludge molten slag has shown to be able to resist wear, polishing effect and weathering actions