An investigation into multivariate variance ratio statistics and their application to stock market predictability

© The Author, 2017. Published by Oxford University Press. All rights reserved. We propose several multivariate variance ratio statistics for "testing" the weak form Efficient Market Hypothesis and for measuring the direction and magnitude of departures from this hypothesis. We derive the asymptotic distribution of the statistics and scalar functions thereof under the null hypothesis that returns are unpredictable after a constant mean adjustment. We propose asymptotic standard errors that are robust to departures from the "no leverage" assumption of Lo and MacKinlay (1988), but are relatively simple and in particular do not require the selection of a bandwidth parameter. We show the limiting behavior of the statistic under a multivariate fads model and under a moderately explosive bubble process: these alternative hypotheses give opposite predictions with regards to the long-run value of the statistics. We apply the methodology to weekly returns for Center for Research in Security Prices size-sorted portfolios from 1962 to 2013 in three subperiods. We find evidence of a reduction of linear predictability in the most recent period, for small and medium cap stocks, but we still reject the multivariate null hypothesis in the most recent period. The main findings are not substantially affected by allowing for a common factor time varying risk premium

Left ventricular myocardial deformation and mechanical dyssynchrony in children with normal ventricular shortening fraction after anthracycline therapy

Objective: The M-mode-derived left ventricular shortening fraction is incorporated into most of the paediatric oncology protocols for monitoring of cardiotoxicity. This study tested the hypothesis that alteration of left ventricular myocardial deformation and mechanical dyssynchrony may occur in asymptomatic children after anthracycline therapy despite having left ventricular shortening fractions within the limits of normal. Design: Cross-sectional study. Setting: Tertiary paediatric cardiac centre. Methods: Left ventricular longitudinal, circumferential and radial myocardial deformation was determined using speckle tracking echocardiography in 45 patients aged 15.3±5.8 years. Real-time three-dimensional echocardiographic data were acquired for the measurement of left ventricular volumes and systolic dyssynchrony index (SDI), the latter derived from the dispersion of time-to-minimum regional volume using a 16-segment model. The results were compared with those of 44 controls. Results: Compared with controls, patients had reduced left ventricular global systolic longitudinal strain (p=0.012), circumferential strain (p4.96%) in patients was 16% (95% CI 6% to 29%). In patients, SDI correlated negatively with left ventricular ejection fraction (r=-0.52, p<0.001), radial strain (r=-0.35, p=0.021), circumferential strain (r=-0.37, p=0.015) and circumferential SR (r=-0.43, p=0.004), but not with the cumulative anthracycline dose (p=0.82). Conclusions: Impaired left ventricular myocardial deformation and mechanical dyssynchrony may exist in children after anthracycline therapy despite having normal left ventricular shortening fractions.published_or_final_versio

Development of prototype smart helmet and blind spot detection for motorcyclist safety features

Motorcycle safety concerns many aspects of vehicle and equipment design as well as operator skill and training that are unique to motorcycle riding. This project focus on the development of prototype smart helmet and blind spot detection features for motorcyclist safety system. The main objective of this work is to reduce the blind spot area for motorcyclists. The developed system are capable of measure appropriate distances (~ 10 cm to 50 cm) of insecurity among motorcyclists and vehicle behind by means of ultrasonic sensors and vibrator motor. The ultrasonic sensor play a role to detect any vehicle from behind the motorcyclist and system will alert the rider through the vibrator motor, LEDs and buzzer that install at the helmet as a warning to the rider about the range of insecurity. The system employed Arduino UNO as the main processing unit to control all the connectivity components. OLED display are also connected to the Arduino UNO mounted in front of the rider for displaying the distance detected by the ultrasonic sensor. Wireless transceiver module is use to serve as a data transmitter and receiver in which transmitted data collected by ultrasonic sensor will wirelessly transmit to the helmet node which is the receiver unit. In conclusion, this developed prototype project work are able to provide better solution for motorcyclist safety features in order to reduce the probability of accidental rate

PHÂN TÍCH ĐỊNH LƯỢNG CÁC CHỈ SỐ ĐA DẠNG SINH HỌC VÀ PHÂN BỐ CỦA THẢM THỰC VẬT THÂN GỖ RỪNG NGẬP MẶN VEN BIỂN MIỀN BẮC VIỆT NAM

The method of quantification of species diversity and distribution by the Shannon- Wiener Index (H’), Index of Similarity (SI), Importance Value Index (IVI), Niche width (bi), Complexity Index (CI), Spatial Distribution (Abundance/ Frequency - A/F) was used to quantify the diversity and distribution of woody true mangroves in Dong Rui, Xuan Thuy national park and Hau Loc along northern coast of Vietnam. The results showed that the species diversity and the structural complexity of the woody true mangrove vegetation at the study sites are relatively low, descending from Dong Rui (H = 1.13; CI = 12.15) to Xuan Thuy National Park (H = 0.62; CI = 11.33) and Hau Loc (H = 0.35; CI = 25.54). However the woody mangrove species compositions of the study sites are not highly different (SI ≥ 0.8). The study results also showed that B. gymnorrhiza, A. corniculatum, R. stylosa, A. marina and K. obovata are dominant species in Dong Rui (IVI = 44.36-76.50); K. obovata and A. corniculatum dominate in Xuan Thuy National Park (IVI = 115.20-148.12); K. obovata is the highly dominant species in Hau Loc (IVI = 222.92). Spatial distribution of almost studied species is continuous (A/F 0.05) indicating the habitat of the species in the study sites is relatively stable.Phương pháp đánh giá định lượng độ da dạng loài và phân bố của các loài thông qua các chỉ số đa dạng loài H, chỉ số tương đồng SI, chỉ số phức tạp CI, chỉ số giá trị quan trọng IVI, độ rộng ổ sinh thái βi và dạng phân bố không gian A/F được áp dụng để đánh giá độ đa dạng loài, dạng phân bố của một số loài cây ngập mặn thực thụ thân gỗ tại Đồng Rui, VQG Xuân Thủy và vùng ven biển huyện Hậu Lộc thuộc vùng ven biển miền Bắc Việt Nam. Kết quả nghiên cứu cho thấy độ đa dạng loài và mức độ phức tạp về cấu trúc thành phân loài cây ngập mặn thực thu thân gỗ tại các địa điểm nghiên cứu tương đối thấp, giảm dần từ Đồng Rui (H = 1,13; CI = 12,15) tới VQG Xuân Thủy (H = 0,62; CI = 11,33) và ven biển huyện Hậu Lộc (H = 0,35; CI = 25,54). Tuy nhiên thành phần loài cây ngập mặn thực thụ thân gỗ tại các địa điểm nghiên cứu có sự tương đồng khá cao (SI ≥ 0,8). Kết quả nghiên cứu cũng cho thấy Vẹt dù (B. gymnorrhiza), Sú (A. corniculatum), Đầng (R. stylosa), Mắm biển (A.  marina), Trang (K. obovata) chiếm ưu thế tại Đồng Rui (IVI = 44,36 - 76,50); Trang (K. obovata) và Sú (A. corniculatum) có mức độ ưu thế cao và lấn át manh mẽ các loài còn lại tại VQG Xuân Thủy (IVI = 115,20 - 148,12); Trang (K. obovata) là loài chiếm ưu thế tuyệt đối tại ven biển huyện Hậu Lộc và là loài lấn át mạnh mẽ các loài còn lại (IVI = 222,92). Hầu hết các loài nghiên cứu có dạng phân bố không gian liên tục (A/F 0,05), phản ảnh môi trường sống của các loài tại các địa điểm nghiên cứu tương đối ổn đinh

Development of cut to length machine using programmable logic controller with human machine interface

Industrial automation helps to eliminate the possibility of human error, reducing costs, saves time-consuming, and achieves higher productivity with better quality with the helps of the control system and technologies that enable industrial processes and machinery to operate automatically. For paper cutting applications, an automated cutter that able to cut the paper at specific lengths and operate according to the parameter setting by the user could help to save cost and time. Therefore, this work is to develop a cut to length machine using the Unitronic Jazz Programmable Logic Controller (PLC) with the combination of Human Machine Interface (HMI) features. This work aims to design and fabricate a small scale cutting machine controlled via a PLC software. To enhance the security system, one-stop center control panel is developed. The iron framework is chosen as a basement of the conveyor and cutter, with the fabrication process consists of five stages. The relationship between the measured speeds of the Alternating Current (AC) induction motor over the frequency range is discussed. From the experiment, the result shows that the machine able to cut the paper with a good precision and accuracy at the length of 1, 5, 6 and 7 inch for the paper type of 50, 70 and 80 gram per square meter (gsm) with the constant pneumatic pressure of 7.5MPa and constant motor speed at 60rpm (2Hz)

RELATIONSHIP BETWEEN CLIMATIC CONDITION AND MANGROVE FOREST STRUCTURE ON NORTHERN COAST OF VIETNAM

The differences in mangrove forest structure, climate, and the linear relationship between climate and mangrove forest structure on the northern coast of Vietnam were analyzed using mangrove forest data measured in 28 sample plots (Dong Rui-8, Xuan Thuy National Park-12 and Lach Sung-8) and climate data collected at the meteorological stations near the study sites (Dong Rui-Tien Yen station, Xuan Thuy National Park-Van Ly station and Lach Sung-Thanh Hoa station) in the period of 1994 - 2012. Results showed that the differences in mangrove forest structure (stem diameter, biomass and basal area) and climate (temperature and rainfall) among study sites were significant (p 0.05). Stem diameter, tree height, basal area and biomass had positive linear relationship with annual average temperature and January average temperature, and negative linear relationship with annual rainfall. A consistently low regression coefficient of less than 0.66 was found among the variables. However, all the regression models were statistically significant (p 0.05). The results could be used to develop multiple linear regression models to predict the change of mangrove ecosystems.The differences in mangrove forest structure, climate, and the linear relationship between climate and mangrove forest structure on the northern coast of Vietnam were analyzed using mangrove forest data measured in 28 sample plots (Dong Rui-8, Xuan Thuy National Park-12 and Lach Sung-8) and climate data collected at the meteorological stations near the study sites (Dong Rui-Tien Yen station, Xuan Thuy National Park-Van Ly station and Lach Sung-Thanh Hoa station) in the period of 1994 - 2012. Results showed that the differences in mangrove forest structure (stem diameter, biomass and basal area) and climate (temperature and rainfall) among study sites were significant (p 0.05). Stem diameter, tree height, basal area and biomass had positive linear relationship with annual average temperature and January average temperature, and negative linear relationship with annual rainfall. A consistently low regression coefficient of less than 0.66 was found among the variables. However, all the regression models were statistically significant (p 0.05). The results could be used to develop multiple linear regression models to predict the change of mangrove ecosystems

Trinitrophenol Reactive T-Cell Hybridomas Recognize Antigens That Require Antigen Processing

Protein antigens must be taken up, processed, and displayed on the surface of antigen-presenting cells in association with major histocompatibility complex molecules before they can be recognized by T cells. Whether recognition of the haptens used to study allergic contact hypersensitivity in murine models similarly requires processing has not been determined. We analyzed whether presentation of trinitrophenol to trinitrophenol reactive T-cell hybridomas requires antigen processing by studying the effects of inhibitors of antigen processing and presentation on tile ability of a syngeneic B-cell tumor (A20) to present trinitrophenol to a series of interleukin-2 producing, trinitrophenol specific, major histocompatibility complex class II-restricted T-cell hybridomas.The ability of trinitrophenol modified A20 cells to stimulate the hybridomas was completely inhibited by rnonoclonal, anti-trinitrophenol, or anti-Ia antibodies and was significantly reduced by paraformaldehyde fixation immediately after trinitrophenol modification. Trinitrophenol-modified A20 cultured at 37°C for 2h prior to fixation was significantly more effective at stimulating the hybridomas than trinitrophenol-modified A20 to present trinitrophenol was inhibited by chloroquine. Paraformaldehyde fixation and chloroquine treatment had similar effects on the ability of trinitrophenol modified lymph node dendritic cells to stimulate the trinitrophenol specific hybridomas. Paraformaldehyde fixation and chloroquine treatment had similar effects on the ability of A20 cells to present ovalbumin to ovalbumin-specific hybridomas as they had on the ability of trinitrophenol modified A20 cells to present trinitrophenol to the trinitrophenol specific hybridomas. One of seven T-cell hybridomas responded to trinitrophenol modified ovalbumin but not other trinitrophenol modified proteins. These results suggest that, at least in part, T cells in the contact hypersensitivity response to trinitrophenol recognize antigens that require processing and that trinitrophenol modified proteins can be recognized

Outage probability analysis for hybrid TSR-PSR based SWIPT systems over log-normal fading channels

Employing simultaneous information and power transfer (SWIPT) technology in cooperative relaying networks has drawn considerable attention from the research community. We can find several studies that focus on Rayleigh and Nakagami-m fading channels, which are used to model outdoor scenarios. Differing itself from several existing studies, this study is conducted in the context of indoor scenario modelled by log-normal fading channels. Specifically, we investigate a so-called hybrid time switching relaying (TSR)-power splitting relaying (PSR) protocol in an energy-constrained cooperative amplify-and-forward (AF) relaying network. We evaluate the system performance with outage probability (OP) by analytically expressing and simulating it with Monte Carlo method. The impact of power-splitting (PS), time-switching (TS) and signal-to-noise ratio (SNR) on the OP was as well investigated. Subsequently, the system performance of TSR, PSR and hybrid TSR-PSR schemes were compared. The simulation results are relatively accurate because they align well with the theory

Outage performance analysis of non-orthogonal multiple access systems with RF energy harvesting

Non-orthogonal multiple access (NOMA) has drawn enormous attention from the research community as a promising technology for future wireless communications with increasing demands of capacity and throughput. Especially, in the light of fifth-generation (5G) communication where multiple internet-of-things (IoT) devices are connected, the application of NOMA to indoor wireless networks has become more interesting to study. In view of this, we investigate the NOMA technique in energy harvesting (EH) half-duplex (HD) decode-and-forward (DF) power-splitting relaying (PSR) networks over indoor scenarios which are characterized by log-normal fading channels. The system performance of such networks is evaluated in terms of outage probability (OP) and total throughput for delay-limited transmission mode whose expressions are derived herein. In general, we can see in details how different system parameters affect such networks thanks to the results from Monte Carlo simulations. For illustrating the accuracy of our analytical results, we plot them along with the theoretical ones for comparison

IoT based smart irrigation control and monitoring system

The "Internet of things" (IoT) has been rapidly developed and applied to the various sector including automotive, manufacture, industrial, and many more. IoT also refers to connecting to another device through a network without any interactions from the human. In this project, the idea is to design and develop an irrigation system that can be control and monitor by using a mobile phone. The purpose of this work is to help agriculture sector in maintaining the moisture of their plantation automatically. The design system should be able to monitor and controller the watering system automatically by detecting the level of moisture in the soil. At the end of the project, smart irrigation system, with an IoT functionality, is successfully designed and tested. Earlier testing provides some promising result, with system can be either automatically controlled or manually control, remotely using smartphone