Ahmad Abdullah Saifizul

Ahmad Abdullah Saifizul
University of Malaya | UM · Department of Mechanical Engineering

Doctor of Engineering

About

61
Publications
18,334
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
442
Citations
Introduction
Ahmad Saifizul currently works at the Department of Mechanical Engineering, University of Malaya. His research interests include Instrumentation and Measurement Technique, Intelligent System, Data Analytics and Intelligent Transportation System. His current research mostly related to Weigh-in-motion, Advanced Traffic Data Collection, Traffic Congestion Measures, Road Safety and Mobility issues involving Heavy Vehicles, Overloading issue, etc.

Publications

Publications (61)
Article
Full-text available
The development of flexible capacitive pressure sensors has recently drawn significant interest among researchers for emerging wearable electronic devices, monitoring applications, and smart systems. However, it still poses enormous difficulty to design capacitive sensors with excellent sensitivity. Few studies have reported the use of interdigitat...
Article
Full-text available
This research introduces an innovative methodology for evaluating and predicting soundboard quality in the intricate craftsmanship of sape instruments. Despite the sape’s profound cultural significance, the process of selecting soundboard wood has been inadequately explored, resulting in uncertainties within the crafting community. Addressing this...
Article
Full-text available
Inerter, a mechanical two-terminal component that has force proportional to relative acceleration between its two terminals, has recently emerged as a promising suspension element to vehicle suspension systems. However, previous research studies have shown that the suspension improvement offered by a passive inerter is marginal. To address this lim...
Article
In this study, a piezoelectric composite was developed based on nitrogen-doped graphene/natural rubber (NGr-NR) and an anionic surfactant sodium dodecyl sulfate (SDS) through a simple sonication method. Taking advantage of the high electrical conductivity and high surface area of NGr, the hybrid network of NGr-NR-SDS nanocomposite showed excellent...
Article
A flexible and stretchable pressure sensor offers significant benefits in human-computer interaction, healthcare, and tactile sensing in robots. We present a novel study optimising Polydimethylsiloxane (PDMS) and graphene-infused unvulcanised natural rubber sensing film to increase sensor sensitivity and dielectric permittivity. By optimising the P...
Article
Full-text available
Enhancement in electrical properties of flexible and stretchable materials such as natural rubber has sparked tremendous attention among researchers to generate a high-performance signal for real-world applications. This is because these materials can be used to create electronic devices that are both flexible and stretchable, which is not possible...
Article
Inerter is a two-terminal component in suspension system such that the force at the two terminals is directly proportional to the relative acceleration of these two points. Studies have shown that the inerter can provide satisfactory vibration isolation for a number of suspension applications, including train suspension, building suspension and veh...
Article
Full-text available
Commercial heavy vehicle is commonly used to transport goods and people efficiently and safely. A previous study has shown a number of gross vehicle weight (GVW) and speed violations recorded in selected areas in Malaysia, and two-axle single unit truck (SUT) is the most commercial heavy vehicle type that violated the weight and speed regulation. M...
Article
Full-text available
[This corrects the article DOI: 10.1371/journal.pone.0280290.].
Chapter
The acoustic properties of wood for musical instruments have been often studied to manufacture good quality soundboards. The soundboard of a musical instrument plays an important role in producing good quality sound. Sape which is a Sarawak traditional musical instrument is a string instrument that is mostly made of a single bole of wood. Local woo...
Article
Full-text available
The inerter is a two-terminal component that can be added to the spring-and-damper configuration of a suspension system. It has the property that the force exerted is proportional to the relative acceleration at its terminals. Studies have demonstrated the inerter’s benefit of providing superior vibration isolation when it is used in the vehicle su...
Article
This paper presents a review of research on musical instrument classification which employed the machine learning system. The two main steps in the automatic classification task are discussed, the feature extraction and the classification. The musical instrument classification follows the Hornbostel-Sachs system. In the feature extraction, the rele...
Article
Full-text available
Malaysia has a high percentage of motorcycles. Due to lane-splitting, travel times of motorcycles are less than passenger cars at congestion. Because of this, collecting travel times using the media access control (MAC) address is not straightforward. Many outlier filtering algorithms for travel time datasets have not been evaluated for their capab...
Article
Full-text available
Heavy vehicles make up a relatively small percentage of traffic volume on Malaysian roads compared to other vehicle types. However, heavy vehicles have been reported to be involved in 30,000–40,000 accidents yearly and caused significantly more fatalities. Rollover accidents may also incur cargo damages and cause environmental or human disasters fo...
Article
Acoustic emission technique is often employed to detect valve abnormalities. With the development of technology, machine learning-based fault diagnosis methods are prevalent in the nondestructive testing industry as they can automatically detect valve problems without any human intervention. Nevertheless, feeding in all possible input parameters in...
Article
Valve problems in reciprocating compressor are often resolved through parameter analysis of acoustic emission (AE) signals or intelligent system without examining the nature of signals related to its source. This study intended to explore the potential of AE signal for the measurement of valve flow rate in order to quantify the severity of valve pr...
Article
Purpose The purpose of this paper is to examine the effect of reciprocating compressor speeds and valve conditions on the roor-mean-square (RMS) value of burst acoustic emission (AE) signals associated with the physical motion of valves. The study attempts to explore the potential of AE signal in the estimation of valve damage under varying compres...
Article
Full-text available
Objective: The increasing number of road crashes and fatalities on Malaysian federal roads is a cause for concern. The main causes of road crashes and fatalities on federal roads have been attributed to the speeding behavior among drivers. As such, this research investigates the possible predictors from sociodemographic characteristics and attitude...
Article
Objective: The increasing number of road crashes and fatalities on Malaysian federal roads is a cause for concern. The main causes of road crashes and fatalities on federal roads have been attributed to the speeding behavior among drivers. As such, this research investigates the possible predictors from sociodemographic characteristics and attitude...
Chapter
Non-intrusive measurement technique, namely, the acoustic emission (AE) technique, is often employed to provide an early detection of valve failures in reciprocating compressor. Past researchers often relate the root-mean-square (RMS) value of AE signal to valve leakages. However, the amount of valve leakage is often unknown. In other words, the de...
Chapter
Acoustic emission (AE) technique is often employed by condition monitoring personnel to detect abnormalities in moving components of machines. Due to its low signal-to-noise ratio at high-frequency range, it often requires certain signal processing technique to extract valuable information from machine parts. This study intends to obtain the charac...
Chapter
Failures in a reciprocating compressor are often caused by the valves, as they are the major moving components in the reciprocating compressor. The acoustic emission (AE) technique has been employed by condition-based monitoring personnel to detect valve problems prior to failure. However, the extent to which the valve should be replaced, or more s...
Article
Full-text available
Numerous studies have proven that the performance of vehicle suspension can be benefited by an inerter in parallel to conventional spring-damper setup, yet its usability in passenger vehicle suspension is still limited by practical consideration in physical implementation. One way of achieving better physical implementation of the parallel inerter...
Article
Full-text available
Speed behaviour has always been associated with road traffic accident in Malaysia andVietnam. The speed behaviour may vary from one moment to another depending on externalfactors or internal factors affecting the driver at that particular moment. Understanding the speedbehaviour between Malaysian drivers & Vietnamese drives are important to pin dow...
Article
Speed behaviour has always been associated with road traffic accident in Malaysia andVietnam. The speed behaviour may vary from one moment to another depending on externalfactors or internal factors affecting the driver at that particular moment. Understanding the speedbehaviour between Malaysian drivers & Vietnamese drives are important to pin dow...
Article
Full-text available
The skid mark is valuable for accident reconstruction as it provides information about the drivers’ braking behaviour and the speed of heavy vehicles. However, despite its importance, there is currently no mathematical model available to estimate skidding distance (SD) as a function of vehicle characteristics and road conditions. This paper attempt...
Article
Full-text available
Speed behaviour has always been associated with road traffic accident in Malaysia and Vietnam. The speed behaviour may vary from one moment to another depending on external factors or internal factors affecting the driver at that particular moment. Understanding the speed behaviour between Malaysian drivers & Vietnamese drives are important to pin...
Article
Full-text available
The experimental approach is usually used as a way to test, modify or optimize vehicle sub-system characteristics. This approach is a time-consuming process, costly and with various limitations. To avoid that, a simulation approach is used. However, to rely on the software, the simulation model has to be validated with the actual vehicle before it...
Article
Full-text available
Quarter vehicle model is the simplest representation of a vehicle that belongs to lumped-mass vehicle models. It is widely used in vehicle and suspension analyses, particularly those related to ride dynamics. However, as much as its common adoption, it is also commonly accepted without quantification that this model is not as accurate as many highe...
Data
All responses for front quarter vehicle model. (XLSX)
Data
All responses for rear quarter vehicle model. (XLSX)
Data
Result parameters for all cases. (XLSX)
Article
Full-text available
Inerter is a recent advancement in vehicle suspension that have been shown to be capable of improving vehicle ride comfort, however its ride improvement is less encouraging in the parallel layout. This study investigated the possibility of further ride improvement brought by vehicle suspensions with a switchable parallel inerter instead. In this th...
Article
The increasing number of young drivers involved in road accidents and fatalities is worrying. Among the common causal of traffic accidents in Malaysia, is believed to be caused by speeding behaviour. Therefore, efforts have been made to understand the characteristics of speeding have uncovered a range of contributory factors about driver's behaviou...
Article
Full-text available
The increasing number of young drivers involved in road accidents and fatalities is worrying. Among the common causal of traffic accidents in Malaysia, is believed to be caused by speeding behaviour. Therefore, efforts have been made to understand the characteristics of speeding have uncovered a range of contributory factors about driver's behaviou...
Article
Full-text available
Recent experiences have shown that one of the main causes of heavy vehicle crashes is the braking performance. In particular, when having to decelerate in an emergency situation, such as when an unexpected object is in the road. Thus, the capability of a vehicle to come to a safe stop is one of the most important factors in preventing more accident...
Article
The conventional approach in vehicle suspension optimization based on the ride comfort and the handling performance requires decomposition of the multi-performance targets, followed by lengthy iteration processes. Suspension tuning is a time-consuming process, which often requires the benchmarking of competitors’ vehicles to define the performance...
Article
Objective: The increase in the number of fatalities caused by road accidents involving heavy vehicles every year has raised the level of concern and awareness on road safety in developing countries like Malaysia. Changes in the vehicle dynamic characteristics such as gross vehicle weight, travel speed, and vehicle classification will affect a heavy...
Article
This study proposed to employ acoustic emission (AE) signal to detect valve abnormalities in reciprocating compressor. The AE signals obtained are post-processed by using wavelet packet transform (WPT) to decompose the signals into different frequency ranges. To examine valve problems, root-mean-square (R.M.S) values of signals computed at each fre...
Article
Full-text available
This paper focuses on the study of the change of various types of riding behaviour, such as speed, brake force, and throttle force applied, when they ride across the speed table. An instrumented motorcycle equipped with various types of sensor, on-board camera, and data logger was used in acquiring the traffic data in the research. Riders were inst...
Article
Increasing number of fatalities caused by road accidents involving heavy vehicles every year has raised the level of concern and awareness on road safety situation in developing countries like Malaysia. This study attempts to explore the influences of vehicle dynamics characteristics such as vehicle weight and travel speed on its safety braking dis...
Article
Motorcyclists are considered a very vulnerable group of road users as far as road accidents are concerned. Safety of this form of transportation is an important issue. This paper details the study on the changes in riding behaviour, such as changes in speed as well as brake force and throttle force applied, when motorcyclists ride over a curve sect...
Article
Full-text available
This paper details the study on the changes in riding behaviour, such as changes in speed as well as the brake force and throttle force applied, when motorcyclists ride over a curve section road using an instrumented motorcycle. In this study, an instrumented motorcycle equipped with various types of sensors, on-board cameras, and data loggers, was...
Article
Full-text available
Vehicle overloading has been identified as one of the major contributors to road pavement damage in Malaysia. In this study, the weigh-in-motion (WIM) system has been used to function as a vehicle weight sorting tool to complement the exsiting static weigh bridge enforcement station. Data collected from the developed system is used to explore the e...
Article
Most highly motorized countries in the world have implemented different speed limits for light weight and heavy weight vehicles. The heavy vehicle speed limit is usually chosen to be lower than that of passenger cars due to the difficulty for the drivers to safely maneuver the heavy vehicle at high speed and greater impact during a crash. However,...
Conference Paper
In recent years, there has been a growing interest in the development of Intelligent Transportation System (ITS), providing safety and comfort to passengers, and thereby decreasing the number of accidents. In addition, the efficiency of highway utilization can be increased tremendously by replacing some of the basis tasks of driving such as acceler...
Article
Full-text available
An Automated Rapid Maxillary Expander (ARME) is a specially designed microcontroller-based orthodontic appliance to overcome the shortcomings imposed by the traditional maxillary expansion appliances. This new device is operates by automatically widening the maxilla (upper jaw) by expanding the midpalatal suture [1]. The ARME appliance that has bee...
Article
Full-text available
Travel time is a basic measure in transportation studies. It is used for performance measures of the developed transportation system. Among many other advanced techniques, Automatic Number Plate Recognition (ANPR) has gained lots of intentions because it is a non-intrusive approach and this system do not required any additional vehicle identificati...
Article
Full-text available
Percutaneous image-guided needle biopsy is typically performed in highly vascular organs or in tumours with rich macroscopic and microscopic blood supply. The main risks related to this procedure are haemorrhage and implantation of tumour cells in the needle tract after the biopsy needle is withdrawn. From numerous conducted studies, it was found t...
Chapter
Full-text available
Percutaneous image-guided needle biopsy is typically performed in highly vascular organs or in tumors with rich macroscopic and microscopic blood supply. The main risks related to this procedure are bleeding and implantation of tumor cells in the needle tract. From numerous conducted studies, it was found that heating the needle tract using a radio...
Conference Paper
Full-text available
This paper presents a controller based on an adaptive network fuzzy inference system (ANFIS) for vision-based lateral vehicle control system. The lateral error and relative yaw angle between vehicle longitudinal road tangent directions at certain look-ahead distance are assumed to be measured by vision system and applied to the controller. The fuzz...
Conference Paper
Full-text available
A stabilization controller of inverted pendulum system must stand the pendulum in the unstable position while moving the cart to the desired position. To deal with this system, a lot of control techniques have been used on the basis of linearized or nonlinear model. In this paper, first, the mathematical models of single inverted pendulum system ar...
Article
Full-text available
Kawalan stereng automatik adalah satu komponen penting dalam pengautomatan lebuhraya, yang kini diselidik di seluruh dunia di bawah beberapa program Intelligent Transportation System (ITS). ITS berpotensi meningkatkan kapasiti lebuhraya yang sedia ada dengan penggunaan yang lebih selamat dan lebih efisien terhadap ruang yang sedia ada. Sistem ini a...
Article
Full-text available
A self-erecting single inverted pendulum (SESIP) is one of typical nonlinear systems. The control scheme running the SESIP consists of two main control loops. Namely, these control loops are swing-up controller and stabilization controller. A swing-up controller of an inverted pendulum system must actuate the pendulum from the stable position. Whil...
Article
The objectives of an automated driver are to let vehicles track the desired trajectory in a natural way and to mantain good ride quality. In order to satisfy the above objectives, this paper use a control technique based on velocity fields concept and Passivity Based Control (PBC) method to derive the control law, such that longitudinal, lateral an...
Article
Full-text available
Expansion of the maxilla is used to correct skeletal and dental transverse discrepancies between the maxilla and mandible. These discrepancies are corrected through a combination of skeletal expansion (separation of the maxillary midpalatal suture) and dental expansion (lateral tipping of the maxillary posterior teeth). The rapid maxillary expansio...

Network

Cited By