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S.Y. Tan

Bio: S.Y. Tan is an academic researcher from University of Malaya. The author has contributed to research in topics: Communications system & Serial port. The author has an hindex of 3, co-authored 3 publications receiving 74 citations.

Papers
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Journal ArticleDOI
TL;DR: This paper designs a remote temperature and relative humidity sensing system that has added advantages compared with existing systems, namely, in its low cost and high memory capabilities and the ability to perform in both real-time as well as off-line.
Abstract: Sensing and recording of relative humidity and temperature plays an important role in many industries. In the past analogue devices were used for measurement of relative humidity and temperature. A simple technique combining analogue and digital circuit theory together with programming techniques has been used in this paper to design a remote temperature and relative humidity sensing system. The sensors analogue signal is applied to a micro-controller based data logger for storage purposes. The data is then transferred to the computer through standard RS232 serial port using the user interface program. The program also allows the user to input some of the important parameters such as sampling interval as well as starting date and time for the logging operation. A back-up power supply is also included to enable the system to remain functional in the event of a power failure. The proposed system has added advantages compared with existing systems, namely, in its low cost and high memory capabilities and the ability to perform in both real-time as well as off-line.

35 citations

Journal ArticleDOI
TL;DR: Window 95-based software, which processes the real time heart sound signal, has been developed and allows for both time varying amplitude graph and power spectral plot (based on 512-point fast Fourier transform (FFT)) to be shown simultaneously on a channel's view.
Abstract: A simple, low cost and non-invasive PC-based system that is capable to process real time fetal phonocardiographic signal has been built. The hardware of the system mainly consists of two modules: the front-end module and the data acquisition & control module. The front-end module is mainly used for heart sound signal capturing and conditioning. A new electronic stethoscope with enhanced performance that is non-intrusive, cost friendly and simple to implement has been built. The audio output unit enables the system to provide simultaneous listening and visual representation of the heart sound. The data acquisition & control module offers a four-channel analog multiplexer, a programmable gain amplifier, and a 12-bit resolution ADC. Various sampling rates can be provided through the programmable timer. Window 95-based software, which processes the real time heart sound signal, has been developed. The software written for the PCG allows for both time varying amplitude graph and power spectral plot (based on 512-point fast Fourier transform (FFT)) to be shown simultaneously on a channel's view. The simultaneous spectrograms gives a much better insight of the heart sounds characteristics than just the time-amplitude plot alone as in conventional PCG software. Using digital signal processing techniques, the power of the spectral plot is used to extract useful information of the heart sounds characteristics even in a situation where the heart sounds are among considerably loud background noises.

34 citations

Journal Article
TL;DR: In this article, a feasibility study on the creation of a robust bi-directional/two-way communication system between an electricity meter and a distant control unit (data concentrator) over the low voltage (LV) distribution grid is presented.
Abstract: Automatic Meter Reading (AMR) is the remote collection of consumption data from customer's utility meters over telecommunications, radio, power line and other links. AMR provides water, electric and gas utility-service companies the opportunities to streamline metering, billing and collection activities, increase operational efficiency and improve customer service. Utility company uses technologies that were developed several decades ago with the majority of the meters being read visually. With manual readings, considerable time is used to physically check out each unit. AMR becomes a viable option to overcome this problem of time wastage to obtain the meter readings. There are many different forms of communication links that can be utilized as the communication medium in an AMR system. One such link is the power line carrier or PLC. The advantages of using the PLC as the communication medium are readily apparent since the power line network is the property of the utility company and its infrastructure is already there. However, power lines are never meant for communication and creates much noise and therefore, various modifications has to be made to make the PLC suitable to be the AMR communication channel. The AMR system consists of three major components: the meter interface module, communications system, and data concentrator. This paper details a feasibility study on the creation of a robust bi-directional/two-way communication system between an electricity meter and a distant control unit (data concentrator) over the low voltage (LV) distribution grid. Basic functions of the AMR system include the provision for remote connection and disconnection of meter and fraud detection features at both the meter interface and the data concentrator. As a support system to the entire AMR, batteries are utilized. They are especially important in the cases of power failures. Lithium-ion batteries are the type of batteries that are used as these batteries tend to last longer than most other batteries. The main advantage of this system is that it is a low cost system that produces very encouraging results and it can be implemented upon existing electro-mechanical meters without the need of purchasing new meters. With many existing meters being the electro-mechanical meters, the need for a high-cost, large-scale implementation of new electronic device meters to enable implementation of the AMR system is unnecessary. The cost of implementation is low and the benefits, especially economically, that it brings to the utility company are immense.

13 citations


Cited by
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Journal ArticleDOI
19 May 2017-Sensors
TL;DR: The approach could offer the potential to be used in clinical practice to establish recommendations for standard electrode placement and find the optimal adaptive filter settings for extracting high quality fetal ECG signals for further processing, and ensure the reliable detection of fetal hypoxia.
Abstract: This paper is focused on the design, implementation and verification of a novel method for the optimization of the control parameters (such as step size μ and filter order N) of LMS and RLS adaptive filters used for noninvasive fetal monitoring. The optimization algorithm is driven by considering the ECG electrode positions on the maternal body surface in improving the performance of these adaptive filters. The main criterion for optimal parameter selection was the Signal-to-Noise Ratio (SNR). We conducted experiments using signals supplied by the latest version of our LabVIEW-Based Multi-Channel Non-Invasive Abdominal Maternal-Fetal Electrocardiogram Signal Generator, which provides the flexibility and capability of modeling the principal distribution of maternal/fetal ECGs in the human body. Our novel algorithm enabled us to find the optimal settings of the adaptive filters based on maternal surface ECG electrode placements. The experimental results further confirmed the theoretical assumption that the optimal settings of these adaptive filters are dependent on the ECG electrode positions on the maternal body, and therefore, we were able to achieve far better results than without the use of optimization. These improvements in turn could lead to a more accurate detection of fetal hypoxia. Consequently, our approach could offer the potential to be used in clinical practice to establish recommendations for standard electrode placement and find the optimal adaptive filter settings for extracting high quality fetal ECG signals for further processing. Ultimately, diagnostic-grade fetal ECG signals would ensure the reliable detection of fetal hypoxia.

92 citations

Journal ArticleDOI
18 Apr 2017-Sensors
TL;DR: This paper focuses on the design, realization, and verification of a novel phonocardiographic- based fiber-optic sensor and adaptive signal processing system for noninvasive continuous fetal heart rate (fHR) monitoring that utilizes two Mach-Zehnder interferometeric sensors.
Abstract: This paper focuses on the design, realization, and verification of a novel phonocardiographic- based fiber-optic sensor and adaptive signal processing system for noninvasive continuous fetal heart rate (fHR) monitoring. Our proposed system utilizes two Mach-Zehnder interferometeric sensors. Based on the analysis of real measurement data, we developed a simplified dynamic model for the generation and distribution of heart sounds throughout the human body. Building on this signal model, we then designed, implemented, and verified our adaptive signal processing system by implementing two stochastic gradient-based algorithms: the Least Mean Square Algorithm (LMS), and the Normalized Least Mean Square (NLMS) Algorithm. With this system we were able to extract the fHR information from high quality fetal phonocardiograms (fPCGs), filtered from abdominal maternal phonocardiograms (mPCGs) by performing fPCG signal peak detection. Common signal processing methods such as linear filtering, signal subtraction, and others could not be used for this purpose as fPCG and mPCG signals share overlapping frequency spectra. The performance of the adaptive system was evaluated by using both qualitative (gynecological studies) and quantitative measures such as: Signal-to-Noise Ratio—SNR, Root Mean Square Error—RMSE, Sensitivity—S+, and Positive Predictive Value—PPV.

76 citations

Journal ArticleDOI
TL;DR: An overview of the existing standards of fetal monitoring is provided and a comprehensive survey on Fetal Phonocardiography is provided with focus on trends in data collection, signal processing techniques and synthesis models that have been developed to date.

71 citations

Journal ArticleDOI
TL;DR: Experimental results indicate that the wireless RH sensor has quite good stability and reproducibility and is potential to construct the low-cost, real-time online wireless gas sensor system, which can be used to monitor the pollutants in the family and the harsh environment.
Abstract: In this paper, we present a wireless relative humidity sensor system prototype which based on quartz crystal microbalance (QCM) coated with nanostructured ZnO as sensing element. The wireless QCM sensor system is composed of two parts: the probe based on QCM sensor and the RF receiver. The probe has two functions: to sense and display the frequency signals and to transmit the signals to the receiver. The receiver connected to the personal computer can receive and record the sensor signals. Experimental results indicate that the wireless RH sensor has quite good stability and reproducibility. The interaction distance between the probe and the receiver can be varied from 5 to 300 m. The proposed system is potential to construct the low-cost, real-time online wireless gas sensor system, which can be used to monitor the pollutants in the family and the harsh environment.

71 citations

Journal ArticleDOI
TL;DR: The results show that the proposed algorithm, in particular some analysis procedures, provides reliable foetal heart rate signals, very close to the reference cardiotocographic recordings.

58 citations