Stock prices’ variability around earnings announcement dates at Karachi Stock Exchange

The purpose of this study is to investigate how earnings announcement event affects stock returns at Karachi Stock Exchange (KSE). For this purpose we use the KSE-100 Index as our sample. We use the CAR Analysis to analyze the impact of earnings announcement over the stock returns around announcement dates. Our results suggest that KSE experiences abnormal stock returns around earnings announcement dates for the overall market and for different categories which indicate that efficient market hypothesis does not hold in Pakistani market and point out the presence of informational dissemination inefficiencies in the marke

Accessibility-Based Approach: Shaping Travel Needs in Pandemic Situation for Planners’ Perspectives

The outbreak of acute respiratory syndrome coronavirus 2 (SARS-Cov-2) causing coronavirus disease (COVID-19) has affected travel behaviors and lifestyles in a matter of days and weeks. In transport planning process, the concept of accessibility is usually interpreted as an acronym of mobility. For decades, researchers have been advocating to interlink the mobility-based approach with accessibility-based approach. Despite considerable research work has been done for the development of accessibility measures, yet its effective use in transport planning is not very pervasive. In this research study, stress is emphasized to reflect on why significant progress for adopting accessibility-based approach has been difficult to accomplish especially in planning practices. Some of the promising efforts made so far have been highlighted. This study provides insights on the power of accessibility-based approach in urban settings and discussed why planners should adopt this approach to reshape safe travel behaviors in uncertain pandemic situations like COVID-19

The impact of cash holding, and exchange rate volatility on the firm’s financial performance of all manufacturing sector in Pakistan

Exchange rate movement is a mostly debatable issue amongst economists and strategic financial planners in the economies as a vital phenomenon, of every economy in the developing the world. This study sets out to examine the impact of cash conversion cycle, Size, Age, and exchange rate movement on firms’ financial decisions. The estimation used techniques of static panel data analysis in this study; pooled OLS, random effects, and fixed effects. Interaction techniques are applied to check the impact of the exchange rate by multiplying this variable with the main variables of cash conversion cycle, that is receivable in days and payables in days. The results depict there is a significant negative relationship between return on assets and exchanger rate during the period of review while the beta of cash conversion cycle has negative value; age and size are positive and significant at 1% level with return on assets. Therefore, it is recommended that organizations that have some measure to agreement in foreign currencies can adopt some advanced hedging technique to occupy the exchange rate movements risk to improve firm’s performance

QuSecNets: Quantization-based Defense Mechanism for Securing Deep Neural Network against Adversarial Attacks

Adversarial examples have emerged as a significant threat to machine learning algorithms, especially to the convolutional neural networks (CNNs). In this paper, we propose two quantization-based defense mechanisms, Constant Quantization (CQ) and Trainable Quantization (TQ), to increase the robustness of CNNs against adversarial examples. CQ quantizes input pixel intensities based on a "fixed" number of quantization levels, while in TQ, the quantization levels are "iteratively learned during the training phase", thereby providing a stronger defense mechanism. We apply the proposed techniques on undefended CNNs against different state-of-the-art adversarial attacks from the open-source \textit{Cleverhans} library. The experimental results demonstrate 50%-96% and 10%-50% increase in the classification accuracy of the perturbed images generated from the MNIST and the CIFAR-10 datasets, respectively, on commonly used CNN (Conv2D(64, 8x8) - Conv2D(128, 6x6) - Conv2D(128, 5x5) - Dense(10) - Softmax()) available in \textit{Cleverhans} library

High Performance and Optimal Configuration of Accurate Heterogeneous Block-Based Approximate Adder

Approximate computing is an emerging paradigm to improve power and performance efficiency for error-resilient application. Recent approximate adders have significantly extended the design space of accuracy-power configurable approximate adders, and find optimal designs by exploring the design space. In this paper, a new energy-efficient heterogeneous block-based approximate adder (HBBA) is proposed; which is a generic/configurable model that can be transformed to a particular adder by defining some configurations. An HBBA, in general, is composed of heterogeneous sub-adders, where each sub-adder can have a different configuration. A set of configurations of all the sub-adders in an HBBA defines its configuration. The block-based adders are approximated through inexact logic configuration and truncated carry chains. HBBA increases design space providing additional design points that fall on the Pareto-front and offer better power-accuracy trade-off compared to other configurations. Furthermore, to avoid Mont-Carlo simulations, we propose an analytical modelling technique to evaluate the probability of error and Probability Mass Function (PMF) of error value. Moreover, the estimation method estimates delay, area and power of heterogeneous block-based approximate adders. Thus, based on the analytical model and estimation method, the optimal configuration under a given error constraint can be selected from the whole design space of the proposed adder model by exhaustive search. The simulation results show that our HBBA provides improved accuracy in terms of error metrics compared to some state-of-the-art approximate adders. HBBA with 32 bits length serves about 15% reduction in area and up to 17% reduction in energy compared to state-of-the-art approximate adders.Comment: Submitted to the IEEE-TCAD journal, 16 pages, 16 figure

Design of cyclic prefix characteristic-based OFDM system for WiMAX technology

Worldwide interoperability for microwave access (WiMAX) offers the wireless connectivity using orthogonal frequency division multiplexing (OFDM) modulation is a proficient wireless technology that capacities high-speed data transmission facilities. The existing WiMAX techniques have the problem of increase in inter-symbol interference (ISI) and bit error rate (BER) at reduced power spectrum that degrades the performance of WiMAX system due to high data rate transmission. The utilization of different adaptive modulation techniques seen as a potential solution to reduce the ISI and BER for high data rate transmission. In this paper, OFDM is adapted using advanced modulation technique for WiMAX system. The technique proposes the cyclic prefix (CP) is utilized that include supplementary bits at the stage of the transmitter. The proposed technique offers minimization of ISI and improvement in BER. It is defined that performance of the existing CP system is equated with the designed single cyclic prefix (SCP) and double cyclic prefix (DCP) and non-cyclic prefix (NCP). BER, probability of error, and power spectral density are utilized to analyse the performance of the designed system. The OFDM based SCP and DCP and NCP for WiMAX are demonstrated for modulation techniques such as; QPSK, BPSK, and QAM. It is determined that BPSK has the smallest BER when compared to QPSK, 16-QAM, and 64-QAM modulations. It is also demonstrated that QPSK is also very competent, however, it has a higher BER as compared to BPSK modulation. It is also observed that 16-QAM and 64-QAM are less efficient in terms of BER compared to QPSK and BPKS modulations. 64-QAM offers the high data rates, and due to high SNR ratio. The designed system is tested for under AWGN and Rayleigh fading channel, and effect power spectral density of signal to noise ratio on OFDM for rayleigh fading channel are demonstrated for SCP and DCP and NCP. It is determined that the OFDM transmitter with proposed DCP for random signals is efficiently reducing the BER and ISI for WiMAX system

Key Performance Indicators for Sustainable Freight Transport and Scenario-based Impediments in Pakistan Freight Industry

Freight transport enables economic growth, market connectivity, and access to the global supply chain systems which contribute to the societal progress and inclusive development of a country. However, it may undermine the sustainable operations by incurring external costs, inefficiency, and economic losses due to non-reliability, poor services, and information systems. In this research study, the Key Performance Indicators (KPIs) for Sustainable Freight Transport Systems (SFTS) are discussed based on available literature review and standards of sustainability measurement in freight transport. Then, based on KPIs some of the scenario-based impediments are highlighted which hinder the performance of the freight transport in Pakistan for achieving sustainable development goals. The core impediments included are Strategic Determinants (SD), Information Systems (IS), Infrastructure Management Systems (IMS) and City Logistics (CL). The negative direct impacts of the key identified factors are also highlighted and linked with each scenario-based impediment. This research study would provide an opportunity for the stakeholders to get tangible idea for policy making and upgradation of the freight transport industry in the country. The highlighted implications will also be validated via expert surveys and Delphi-analysis in the future study.

Implementation of STEM-Based Experiential Learning to Improve Critical Thinking Skills on Ecosystem Materials

The low critical thinking skills of learners are triggered by less supportive learning. The learning process has not emphasized the development of critical thinking skills, it is because in learning learners tend to memorize concepts so that critical thinking skills are not trained, making learners less active in the learning process and not achieving minimum completion criteria, there needs to be efforts to overcome them. The formulation of the problem in this study is: Is there a significant difference in the improvement of students' critical thinking skills with the implementation of STEM-based Experiential Learning learning in class VII MTsN Aceh Besar? This research aims to find out the significance of differences in improving learners' critical thinking skills with the implementation of STEM-based Experiential Learning learning. The method used in this study is an experimental method with the design of One Group Pretest-Postets design. The population of this study is all students of class VII MTsN Aceh Besar which amounted to 120 learners. The instrument used to measure critical thinking skills using multiple choice questions is 10 questions. Data analysis using the One Simple t-Test test at a significant level of 0.05. The results of the One Simple t-Test test of the students' critical thinking skills were obtained by Sig. (0.00) < (0.05), showed that learners' critical thinking skills were better and there was a significant improvement with the implementation of STEM-based Experiental Learning