A speech enhancement improvement in communication through hearing protection device

This book is written with the main purpose to distribute the knowledge ofone of the many studies made about enhancing speech enhancement in communication among those workers who wear hearing protection devices (HPD) as part of the Hearing Conservation Programme (HCP). A HCP may be as important as if no other engineering approach or from the management side is impractical, therefore the HPD must be worn whenever and wherever required. Nowadays, there are so many HPD like the earmuff that provide the user to protect their hearing if said properly worn. Some of the HPDs have the feature that allowing the speech of a worker to be understood by the other whom wear HPD that block out unnecessary noise. In the engineering approach, many researchers have study about many methods to achieve the communication while HPD worn. In addition, the importance of the communication at noisy workplace is that it may give warning indicator and clear instruction. In the public health perspective, wearing a HPD is a method to reduce the occurrence of occupational Noise Induced Hearing Loss (NIHL). However, HPD usage is not liked at all time or for all workers, thus they tend to not use the device accordingly. One of the reason is the user cannot make good communication while wearing HPD. It is hopefully, through the written content of this book, people would have a better option of HPD with appropriate communication feature by continuing previous researches made

A review: Simultaneous localization and mapping algorithms

Simultaneous Localization and Mapping (SLAM) involves creating an environmental map based on sensor data, while concurrently keeping track of the robot’s current position. Efficient and accurate SLAM is crucial for any mobile robot to perform robust navigation. It is also the keystone for higher-level tasks such as path planning and autonomous navigation. The past two decades have seen rapid and exciting progress in solving the SLAM problem together with many compelling implementations of SLAM methods. In this paper, we will review the two common families of SLAM algorithms: Kalman filter with its variations and particle filters. This article complements other surveys in this ?eld by reviewing the representative algorithms and the state-of-the-art in each family. It clearly identifies the inherent relationship between the state estimation via the KF versus PF techniques, all of which are derivations of Bayes rule

Peripheral photoplethysmography variability analysis of sepsis patients

Sepsis is associated with impairment in autonomic regulatory function. This work investigates the application of heart rate and photoplethysmogram (PPG) waveform variability analysis in differentiating two categories of sepsis, namely systemic inflammatory response syndrome (SIRS) and severe sepsis. Electrocardiogram-derived heart period (RRi) and PPG waveforms, measured from fingertips (Fin-PPG) and earlobes (Ear-PPG), of Emergency Department sepsis patients (n = 28) with different disease severity, were analysed by spectral technique, and were compared to control subjects (n = 10) in supine and 80° head-up tilted positions. Analysis of covariance (ANCOVA) was applied to adjust for the confounding factor of age. Low-frequency (LF, 0.04-0.15 Hz), mid-frequency (MF, 0.09-0.15 Hz) and high-frequency (HF, 0.15-0.60 Hz) powers were computed. The normalised MF power in Ear-PPG (MFnu Ear) was significantly reduced in severe sepsis patients with hyperlactataemia (lactate > 2 mmol/l), compared to SIRS patients (P 0.05), suggesting that there may be a link between 0.1 Hz ear blood flow oscillation and tissue metabolic changes in sepsis, in addition to autonomic factors. The study highlighted the value of PPG spectral analysis in the non-invasive assessment of peripheral vascular regulation in sepsis patients, with potential implications in monitoring the progression of sepsis

Sloshing in a closed domain under unidirectional excitation

1145-1153Sloshing is a phenomenon where a partially filled tank is exerted into various environmental sea conditions, such as wave and wind. Sloshing in a tank of liquefied natural gas carrier can lead to structural damage of tank structures and motion instability of the carrier. Thus, sloshing analysis needs to be conducted beforehand to minimize the risk of damages. This paper presents experimental and numerical study on sloshing phenomenon in a prismatic membrane tank model under unidirectional excitation with 30% water filling condition. A regular wave motion stimulated by the linear actuator was applied to the model tank and recorded by a video camera. Meanwhile, OpenFoam software was used to simulate the sloshing numerically in a volume of fluid method based on Navier-Stokes theorem. The sloshing patterns and free surface elevation in the prismatic membrane model tank, with the same input amplitude and frequency, were investigated for both cases. Both experimental and simulation results showed reasonable agreement on the sloshing profile, while the internal free surface elevation in the closed domain indicated a deviation with maximum absolute error of 4.9 cm

Motion Control of Nonholonomic Wheeled Mobile Robot in a Structured Layout

This paper describes the incorporation of active force control (AFC) scheme into two different resolved motion acceleration control (RMAC) models, i.e. RMAC with proportional-plus-derivative (RMAC-PD) and RMAC with proportional-plus-integralplus- derivative (RMAC-PID). The two newly formulated control models are subsequently implemented as the proposed motion controllers for the nonholonomic wheeled mobile robot (WMR). By embedding AFC into both the RMAC schemes, the performance of the robotic system was studied in which the WMR was required to track a collision-free trajectory in a structured layout that has been prescribed by a trajectory planner. The effectiveness of both the controllers were then experimented and compared to determine the accuracy and trackability of the WMR. The WMR was also subjected to disturbances for the testing of the system robustness. With appropriately computed inertia matrix and finely tuned RMAC control parameters, the WMR was found to be very robust and effective in trajectory tracking task in spite of the complexity of the operating and loading conditions

Implementation of motion planning and active force control to a virtual wheeled mobile robot

The research focuses on the development of a virtual wheeled mobile robot (WMR) simulator that integrates the essential aspects of motion planning, motion control and virtual reality (VR) technique. The developed simulator may serve as a virtual testbed for the repetitive experimentation of the proposed mobile robot control scheme within a specified workspace or layout. The motion path planning is based on the A*heuristic search algorithm with a specific reference to the sixelementary jumps graph for the generation of a nonholonomic global collision-free path environment. A robust active force control (AFC) strategy is incorporated as the WMR motion controller that can accommodate effective disturbance compensation control action in order to produce accurate trajectory tracking task even in the wake of the modelled disturbances. A trajectory planner has been deliberately introduced as the interface between the motion planner and the motion controller. Later, a VR technique is applied to create the virtual environment (VE) that effectively integrates the main elements and transforms the system into a virtual WMR simulator with the added features that will enable researcher to perform experimentation of the mobile robot. A case study is furnished in the research study taking into account a computer integrated manufacturing (CIM) layout in which the proposed mobile robot is supposed to navigate. A rigorous simulation study is performed to demonstrate the effectiveness of the proposed system. Results clearly indicate the successful realization as well as implementation of the developed virtual WMR simulator in which the WMR has been conclusively shown to be very stable, robust and accurate in its tracking ability

Path planning of mobile robot for autonomous navigation of road roundabout intersection

The aim of this research is to develop a robust navigation system for mobile robot in a road roundabout setting using laser range finder (LRF) and vision system. A new algorithm for combining the LRF and vision system is investigated to detect the open space area in a road roundabout. The study focuses on the simulation and experimentation of the mobile robot ability to effectively track the path when countering a roundabout with and without obstacle and considering a number of scenarios. The system is simulated using MATLAB with the grid map used to create the road roundabout environment and select the path according to the respective road rules. The experiments are performed using simple platform with laser range finder and the data are processed in real-time in Matlab. Good results from both simulation and experiments show the effectiveness of the proposed algorithm

Neural-network prediction of riser top tension for vortex induced vibration suppression

Vortex induced vibration (VIV) of marine riser is a significant challenge for the offshore oil and gas industry. Traditional passive suppression devices which are commonly used in permanent production risers to reduce the risks of collision caused by VIV are less practical to be utilized in short-term drilling operation due to expensive overhead cost and installation time factors. This paper studied active control of riser VIV by tuning the tensioner output force (pretension) so that this method can be utilized in short-term operation, such as drilling, without adding additional high-cost systems. A novel active control method by using neural network in tuning top tension of marine riser was studied to examine the effectiveness of VIV suppression. A response surface was derived from VIV experimental data and used to predict the targeted riser top tension to be exerted by the tensioner under different conditions. Reduction of VIV amplitude has been identified for the range of applicability. The findings of this paper have identified the practical scope of active control for riser top tension tuning to suppress VIV