Calibrating and Evaluating Dynamic Rule-Based Transit-Signal-Priority Control Systems in Urban Traffic Networks

Setting the traffic controller parameters to perform effectively in real-time is a challenging task, and it entails setting several parameters to best suit some predicted traffic conditions. This study presents the framework and method that entail the application of the Response Surface Methodology (RSM) to calibrate the parameters of any control system incorporating advanced traffic management strategies (e.g., the complex integrated traffic control system developed by Ahmed and Hawas). The integrated system is a rule-based heuristic controller that reacts to specific triggering conditions, such as identification of priority transit vehicle, downstream signal congestion, and incidents by penalizing the predefined objective function with a set of parameters corresponding to these conditions. The integrated system provides real time control of actuated signalized intersections with different phase arrangements (split, protected and dual). The premise of the RSM is its ability to handle either single or multiple objective functions; some of which may be contradicting to each other. For instance, maximizing transit trips in a typical transit priority system may affect the overall network travel time. The challenging task is to satisfy the requirements of transit and non-transit vehicles simultaneously. The RSM calibrates the parameters of the integrated system by selecting the values that can produce optimal measures of effectiveness. The control system was calibrated using extensive simulation-based analyses under high and very high traffic demand scenario for the split, protected, and dual control types. A simulation-based approach that entailed the use of the popular TSIS software with code scripts representing the logic of the integrated control system was used. The simulation environment was utilized to generate the data needed to carry on the RSM analysis and calibrate the models. The RSM was used to identify the optimal parameter settings for each control type and traffic demand level. It was also used to determine the most influential parameters on the objective function(s) and to develop models of the significant parameters as well as their interactions on the overall network performance measures. RSM uses the so-called composite desirability value as well as the simultaneous multi-objective desirabilities (e.g., the desirability of maximizing the transit vehicles throughput and minimizing the average vehicular travel time) estimates of the responses to identify the best parameters. This study also demonstrated how to develop “mathematical” models for rough estimation of the performance measures vis-à-vis the various parameter values, including how to validate the optimal settings. The calibrated models are proven to be significant. The optimal parameters of each control type and demand level were also checked for robustness, and whether a universal set of relative parameter values can be used for each control type. For the high traffic demand level, the optimal set of parameters is more robust than those of the very high traffic demand. Besides, the dual actuated controller optimal setting under the very high traffic demand scenario is more robust (than other control types settings) and shows the best performance

Income smoothing behavior among US banks a comparison of before and after policy change in 1999

We investigate income smoothing behaviour for US bank holding companies. Our sample period covers from 1991 to 2013. We investigate whether policy change in late 90s affects income smoothing behaviour. Federal Financial Institutions Examination Council (FFIEC) introduced restrictive regulations to charge off of homogenous loans. We find that income smoothing continues even after the policy change but the association between provisioning and heterogeneous loans is not evident. However we get a significant positive association between provisioning and noninterest income. Moreover policy impacts in income smoothing process. The association between previous year charge off of homogenous loan and current year recovery was strong in 90s US financial institution. But after policy change, this relationship weakened. However, income smoothing avenue through previous year charge off of heterogeneous loan and current year recovery is still obvious. The association between current year recovery and gross loan charge off does not change for homogenous loan after policy change but this relationship for heterogeneous loan is stronger even after policy change

An Empirical Study of the Relationship between Macroeconomic Variables and Stock Price: A Study on Dhaka Stock Exchange (DSE)

Literature strongly supports vibration of the stock price as a consequence of various macroeconomic factors (Darrat, 1990; Fama & Schwert, 1977; Jaffe & Mandelker, 1976; Nelson, 1976; Pearce & Roley, 1985; Ripley, 1973). This study has investigated the explanatory power of various macro-factors such as inflation rate, exchange rate, interest rate, money supply and production index on the variability of the stock price in Bangladesh. Multiple regression analysis has been conducted to asses the relationship between the stated macro economic factors with stock price. All share price index of the Dhaka Stock Exchange has been used as a proxy for stock price, the dependent variable of the study. No significant relationship has been found between the stock price and any of the macroeconomic factors. The study bodes well for advanced empirical models with additional macroeconomic variables.

Understanding the determinants of mHealth apps adoption in Bangladesh: A SEM-Neural network approach

Due to the low adoption rate of mHealth apps, the apps designers need to understand the factors behind adoption. But understanding the determinants of mHealth apps adoption remains unclear. Comparatively less attention has been given to the factors affecting the adoption of mHealth apps among the young generation. This study aims to examine the factors influencing behavioral intention and actual usage behavior of mHealth apps among technology prone young generation. The research model has extracted variables from the widely accepted Unified Theory of Acceptance and Use of Technology (UTAUT2) alongside privacy, lifestyles, self-efficacy and trust. Required data were collected from mHealth apps users in Bangladesh. Firstly, this study confirmed that performance expectancy, social influence, hedonic motivation and privacy exerted a positive influence on behavioral intention whereas facilitating conditions, self-efficacy, trust and lifestyle had an influence on both behavioral intention and actual usage behavior. Secondly, the Neural Network Model was employed to rank relatively significant predictors obtained from structural equation modeling (SEM). This study contributes to the growing literature on the use of mHealth apps in trying to elevate the quality of patients' lives. The new methodology and findings from this study will significantly contribute to the extant literature of technology adoption and mHealth apps adoption intention especially. Therefore, for practitioners concerned with fostering mHealth apps adoption, the findings stress the importance of adopting an integrated approach centered on key findings of this study

Seasonal pattern of zooplankton communities and their environmental response in subtropical maritime channels systems in the Bay of Bengal, Bangladesh

Zooplankton are a primary component of aquatic food chain and play an important role in the functioning of aquatic food webs. Seasonal variation in community structures of zooplankton and potential environmental drivers were studied, during a 1-year cycle (summer 2015 – spring 2016) in subtropical maritime channels systems in the Bay of Bengal, coastal waters in Bangladesh. A total of 32 species representing 25 families, 13 orders and 15 taxonomic groups were identified. Of these species, 23 distributed in all four season of which 8 were dominant species with high contributions of the total communities. Species number was peaked in autumn and fell in summer while maximum abundance was in the winter and minimum in summer. Multivariate analyses showed that there was a clear seasonal shift in zooplankton community structures in relation with environmental conditions. Species diversity and evenness peaked in summer while the high value of species richness was found in autumn. Multivariate correlation (RELATE) and BIO-ENV analysis demonstrated that seasonal variation in community patterns was significantly correlated with temporal shift of environmental conditions and that variation mainly driven by water transparency, salinity, DO, TSS and nutrients. Thus, this finding implies that the zooplankton community represented a clear seasonal shift shaped by environmental drivers in subtropical channels systems

Factors that Influence the decision when buying second-hand products.

Buying and selling of used goods is something that has been done for centuries. Throughout the last 20 years, rapid growth of second-hand products consumption has got the attention of researchers and raised the question why customers buy second-hand products. The growth of the Internet has developed different applications, and this combined with the introduction of new electronic devices, provides users with buying and selling facilities of goods over the Internet and mobile devices. The uses of social networks and smart-phones have also revolutionized the second-hand product market among all economic classes. The consumption of second-hand products is increasing daily. Therefore it is important to pay attention to the factors that affect the purchase of second-hand products since it is not a simple form of mercantilism. It's a lifestyle, a way to acquire goods that we need and get rid of those that we do not see as useful anymore. The purpose of this study is to create new knowledge in the area of second-hand products consumption and customer buying behavior by identifying factors that influence the customer in buying second-hand products. In order to fulfill the research purpose, a quantitative research approach and cross sectional research design were adopted. Questionnaires were designed using Google survey tool and through this method 169 questionnaires were collected from respondents. After which, SPSS was used to perform the required tests of descriptive statistics, reliability analysis, bivariate correlation, single item measurement and multiple regression analysis. It was observed that price was the most important factor influencing customers when purchasing second-hand products; risk is the second most influencing factor and brand is the third and location come last as most influencing factor.  The results show that the factors such as brand, price and purchase intention of second-hand products have no association and influence on each other during the purchase decision. In contrast, risk and location factors have a weak association with each other but both factors lack association with brand, price and intention. This study contributes to the existing literature on second-hand products consumption and customer buying behavior as well as touching upon theories of brand, price, risk, and seller location

Impact of Extreme Rainfall Event over Swedish Urban Catchments : A study on catchment characterization in the context of Aerial Reduction Factor and storm movement

The design practices of urban hydraulic structures are required to be based on enough safety measures in addition to cost efficiency for sustainable development. Overestimation of catchment runoff generated from a storm event can increase the project cost unnecessarily. For urban pluvial studies, use of Aerial Reduction Factor (ARF) helps to estimate the probable precipitation intensity inside a catchment. By understanding the necessity of using ARF from a national context and applying it in present design practices can pave the way towards sustainable design practices. In this study the applicability of ARF from Swedish urban context was analyzed. The urban catchments for fifty biggest Swedish cities were delineated and the catchment parameters were analyzed. Application of ARF depends on the size of catchment. To experience a significant reduction in catchment outlet discharge, the minimum catchment area for application of ARF was reported as 5 km2. According to the analyzed parameters, ninety percent of catchment sizes in Swedish urban area were found less than 5 km2, which are quite small in respect of ARF applicability. It was realized from the analysis that application of ARF within a single catchment is not much necessary for pluvial studies in Swedish urban catchments due to catchment properties. In addition to rainfall intensity, rainfall movement also changes the runoff behavior from a catchment. When catchment’s flow velocity and direction through main channel and storm moving velocity and direction over the channel coincides with each other, then the outlet peak discharge magnifies in comparison to a stationery storm, known as resonance effect. The impact of storm movement over catchment was analyzed using HEC-HMS modelling with varying storm movement velocity over catchment. The analysis was performed on 12 catchments of different size and flow velocity. It was found that the peak discharge can increase up to 46 percent depending upon catchment characteristics. The flow velocity through all the delineated catchments of fifty cities were calculated using USDA’s NRCS TR-55 method and then compared with usual storm moving velocities in Sweden. It was found that, due to flat nature of Swedish urban areas, the flow velocities are very low (<2 m/s) in compare to average storm velocity (8 m/s), portraying the fact that there is limited probability that these velocities will coincide. But for any area where storm velocity is normally low, resonance effect can happen. Precise analysis based on local conditions are suggested while modelling a particular area, since impact of resonance effect can overrun the design considerations

Impact of Extreme Rainfall Event over Swedish Urban Catchments : A study on catchment characterization in the context of Aerial Reduction Factor and storm movement

The design practices of urban hydraulic structures are required to be based on enough safety measures in addition to cost efficiency for sustainable development. Overestimation of catchment runoff generated from a storm event can increase the project cost unnecessarily. For urban pluvial studies, use of Aerial Reduction Factor (ARF) helps to estimate the probable precipitation intensity inside a catchment. By understanding the necessity of using ARF from a national context and applying it in present design practices can pave the way towards sustainable design practices. In this study the applicability of ARF from Swedish urban context was analyzed. The urban catchments for fifty biggest Swedish cities were delineated and the catchment parameters were analyzed. Application of ARF depends on the size of catchment. To experience a significant reduction in catchment outlet discharge, the minimum catchment area for application of ARF was reported as 5 km2. According to the analyzed parameters, ninety percent of catchment sizes in Swedish urban area were found less than 5 km2, which are quite small in respect of ARF applicability. It was realized from the analysis that application of ARF within a single catchment is not much necessary for pluvial studies in Swedish urban catchments due to catchment properties. In addition to rainfall intensity, rainfall movement also changes the runoff behavior from a catchment. When catchment’s flow velocity and direction through main channel and storm moving velocity and direction over the channel coincides with each other, then the outlet peak discharge magnifies in comparison to a stationery storm, known as resonance effect. The impact of storm movement over catchment was analyzed using HEC-HMS modelling with varying storm movement velocity over catchment. The analysis was performed on 12 catchments of different size and flow velocity. It was found that the peak discharge can increase up to 46 percent depending upon catchment characteristics. The flow velocity through all the delineated catchments of fifty cities were calculated using USDA’s NRCS TR-55 method and then compared with usual storm moving velocities in Sweden. It was found that, due to flat nature of Swedish urban areas, the flow velocities are very low (<2 m/s) in compare to average storm velocity (8 m/s), portraying the fact that there is limited probability that these velocities will coincide. But for any area where storm velocity is normally low, resonance effect can happen. Precise analysis based on local conditions are suggested while modelling a particular area, since impact of resonance effect can overrun the design considerations