adisorn kaewpukdee - Academia.edu (original) (raw)
Papers by adisorn kaewpukdee
JURNAL INFOTEL
PhET is one of the most powerful and impressive simulator innovations, widely used in the STEM-ba... more PhET is one of the most powerful and impressive simulator innovations, widely used in the STEM-based learning process. Based on literature reviews, students are allowed to independently practice their skills and understanding of the material concept using this tool. PheT involves students in process competencies comprehensively and also provides a highly interactive virtual environment for STEM materials, including basic electronics, a sub-category of physics. This tool can also be easily accessed online at https://phet.colorado.edu/ or offline with a note that the user should download and install the application on a PC. An interesting question regarding this education tool is, "can PhET support basic electronics learning in Higher Education (HE)?" Numerous preliminary studies have not answered this question, which is associated with the technical aspect of the tool, because they only focused on the pedagogical aspect. Therefore, this research aims to fill this gap by exp...
Advanced Materials Research, 2013
The current data recording technology is approaching its capacity limit approximately 1 Tbit/in2 ... more The current data recording technology is approaching its capacity limit approximately 1 Tbit/in2 (terabits per square inch) known as superparamagnetic limit. Heat-assisted magnetic recording (HAMR) is one of the promising technologies that is being planned to be used as a new data recording technology to achieve the storage capacity beyond 1 Tbit/in2. In HAMR, the laser is applied to heat a magnetic medium during the writing process, which results in the unique transition characteristics if compared to a conventional system. This paper investigates the effects of thermal and cross-track variations to the transition characteristics (both transition center and transition parameter) of longitudinal HAMR systems. Experimental results indicate that the longitudinal HAMR system can withstand some amount of thermal and cross-track variations and still provides satisfactory system performance.
Computers, Materials & Continua
Visible Light Communication (VLC) technology is aggressive research for the next generation of co... more Visible Light Communication (VLC) technology is aggressive research for the next generation of communication. Currently, Radio Frequency (RF) communication has crowed spectrum. An Intelligent Transportation System (ITS) has been improved in the communication network for Vehicle-to-Vehicle (V2 V), Vehicle-to-Infrastructure (V2I), and Infrastructure-to-Vehicle (I2 V) by using the visible light spectrum instead of the RF spectrum. This article studies the characterization of Line-of-Sight (LOS) optical performance in an Outdoor Wireless Visible Light Communication (OWVLC) system employing a Multiple-Input Multiple-Output (MIMO) technique for I2 V communications in ITS regulations. We design the new configuration of the OWVLC-I2 V system, which is an alternative approach to communication for I2 V system at nighttime. The results show the Channel Impulse Response (CIR) of the LOS links in visible light communication for I2 V system in ITS by investigating the receiver on the vehicle moving along the coverage communication area. Furthermore, the OWVLC-I2 V system using the MIMO technique depicts the performance of throughput and Bit Error Rate (BER) vs. vehicle speed while the vehicle passes a street light.
White LED will be a dominant device for lighting in the near future through which we can have the... more White LED will be a dominant device for lighting in the near future through which we can have the luminance and data transmission simultaneously. An indoor wireless visible light communication system (IWVLC) describes the communication during the indoor applications. This paper presents an iterative receiver design for the IWVLC system and proposes the Soft-Output-Viterbi algorithm to equalize and detect the signal at the receiver of the IWVLC system which is based on the numerical simulation. The performance of the proposed algorithm is better than the conventional Viterbi algorithm in terms of the bit error rate. The simulation results unveil the performance of the proposed iterative algorithm where it can be seen that the BER comes out to be less at the same SNR (dB) as compared to the conventional ones even when the data rate is very high.
White LED will be a dominant device for lighting in the near future through which we can have the... more White LED will be a dominant device for lighting in the near future through which we can have the luminance and data transmission simultaneously. An indoor wireless visible light communication system (IWVLC) describes the communication during the indoor applications. This paper presents an iterative receiver design for the IWVLC system and proposes the SoftOutput-Viterbi algorithm to equalize and detect the signal at the receiver of the IWVLC system which is based on the numerical simulation. The performance of the proposed algorithm is better than the conventional Viterbi algorithm in terms of the bit error rate. The simulation results unveil the performance of the proposed iterative algorithm where it can be seen that the BER comes out to be less at the same SNR (dB) as compared to the conventional ones even when the data rate is very high.
In order to promote the extremely high areal density of perpendicular magnetic recording system t... more In order to promote the extremely high areal density of perpendicular magnetic recording system that is approaching its super-paramagnetic limit, the future technology known as heat-assisted magnetic recording (HAMR) has been proposed. Because perpendicular recording has many advantages over longitudinal recording, including high write field amplitude, sharp field gradient, well-aligned medium, less demagnetization field at transition, and so on. Thus the HAMR system is currently developed as extension of this perpendicular magnetic recording scheme. In this paper, we study the transition characteristics of perpendicular HAMR systems by varying some concerned parameters (e.g., peak temperature, write head gap, deep gap field, etc.) to optimize the performance of the HAMR system. Results show that the write head gap and the deep gap field are crucial parameters that are needed to be minimized so as to achieve high performance. In addition, we use each transition center in the simulat...
Optical design has played a key role in the optical wireless communications since it can enhance ... more Optical design has played a key role in the optical wireless communications since it can enhance the gains and the fields of view (FOVs) of the receivers without power consumption. In this paper, we propose an optical front end which is comprised of a multipleradius concave mirror, lens, and a detector so as to enlarge coverage areas of the optical wireless access point for an indoor scenario. The numerical investigation into performance of the proposed and the conventional optical concentrators has been conducted and presented. From the numerical studies, it is clear that although the proposed concentrator offers a smaller gain, it provides a significantly larger FOV in the indoor environment, resulting the substantially large coverage areas. As the proposed optical front end facilitates the ease of the manufacture and the broad coverage, its deployment at the uplink could reduce the installation cost.
Currently, a conventional magnetic recording system is approaching its storage capacity known as ... more Currently, a conventional magnetic recording system is approaching its storage capacity known as a super paramagnetic limit. Heat-assisted magnetic recording (HAMR) is one of new technologies that can achieve an areal density beyond this limit. In HAMR, the heat is applied in a medium during writing process resulting in unique transition characteristics if compared to a conventional system. This paper studies the effect of peak temperature and cross-track variations on the transition characteristics of a perpendicular HAMR system. Numerical results based on thermal Williams-Comstock and micro-track models show that these two variations cause the transition center and the transition parameter to vary, thus affecting the transition response of the HAMR system.
In near future, the conventional electric lamps will be replaced by the white light emitting diod... more In near future, the conventional electric lamps will be replaced by the white light emitting diode (LED) lamps because it offers many advantages such as low power consumption, long life time, small size, cool operation system. This work proposes the receiver design based on a partial-response maximumlikelihood technique for the indoor wireless visible light communication system, where a transmitter is placed on the ceiling, a receiver is on the table, and the signal transmission is based on the on-off keying intensity modulation. In addition, we also compare the performance between the proposed system and the conventional analog system in terms of bit-error rate at different data rates.
Currently, a conventional magnetic recording system is approaching its storage capacity known as ... more Currently, a conventional magnetic recording system is approaching its storage capacity known as a super paramagnetic limit. Heat-assisted magnetic recording (HAMR) is one of new technologies that can achieve an areal density beyond this limit. In HAMR, the heat is applied in a medium during writing process resulting in unique transition characteristics if compared to a conventional system. This paper studies the effect of peak temperature and cross-track variations on the transition characteristics of a perpendicular HAMR system. Numerical results based on thermal Williams-Comstock and micro-track models show that these two variations cause the transition center and the transition parameter to vary, thus affecting the transition response of the HAMR system.
In order to promote the extremely high areal density of perpendicular magnetic recording system t... more In order to promote the extremely high areal density of perpendicular magnetic recording system that is approaching its super-paramagnetic limit, the future technology known as heat-assisted magnetic recording (HAMR) has been proposed. Because perpendicular recording has many advantages over longitudinal recording, including high write field amplitude, sharp field gradient, well-aligned medium, less demagnetization field at transition, and so on. Thus the HAMR system is currently developed as extension of this perpendicular magnetic recording scheme. In this paper, we study the transition characteristics of perpendicular HAMR systems by varying some concerned parameters (e.g., peak temperature, write head gap, deep gap field, etc.) to optimize the performance of the HAMR system. Results show that the write head gap and the deep gap field are crucial parameters that are needed to be minimized so as to achieve high performance. In addition, we use each transition center in the simulation result to calculate nonlinear transition shift (NLTS) value to observe the dependence of NLTS on the distance between transitions and the relationship between write head gap. The results lead to the observation that the wide write head gap will increase the NLTS in the system, which degrade the overall system performance.
This paper proposes a product test time reduction. Our method employs statistical process control... more This paper proposes a product test time reduction. Our method employs statistical process control (SPC) and process capability analysis (PCA) as a tool. Algorithm verification was made upon the collected data of a specific product type. Box-Cox transformation has been applied to those data sets that hold non-normal distribution. Minitab software package was used as a mathematical analysis tool. The obtained result has convinced us the benefit of non-normal distribution to normal distribution data transformation. By applying the method to major time-consuming sub-processes, the test times could be reduced considerably. Proportionally required power can be saved. This study is of benefit not only in term of manufacturing cost reduction but also productivity enhancement.
Procedia Engineering
The current magnetic recording technology is approaching its theoretical boundary known as a supe... more The current magnetic recording technology is approaching its theoretical boundary known as a super-paramagnetic limit. Heat-assisted magnetic recording (HAMR) is one of the promissing technologies enabling higher recording capacity beyond this limit. In HAMR, the heat is applied in a medium during writing process resulting unique transition characteristics if compared to a conventional scheme. In this paper, we investigate the effect of different parameters, including the peak temperature, medium coercivity, a write head gap, a deep gap field, and a distance from pole to medium (or a fly height), on the transition characteristics of the longitudinal HAMR system. Numerical results indicate that there exists an optimal parameter setting which minimizes the transition enter and the transition parameter so as to provide high storage capacity.
ABSTRACT Currently, a conventional magnetic recording system is approaching its storage capacity ... more ABSTRACT Currently, a conventional magnetic recording system is approaching its storage capacity known as a super paramagnetic limit. Heat-assisted magnetic recording (HAMR) is one of new technologies that can achieve an areal density beyond this limit. In HAMR, the heat is applied in a medium during writing process resulting in unique transition characteristics if compared to a conventional system. This paper studies the effect of peak temperature and cross-track variations on the transition characteristics of a perpendicular HAMR system. Numerical results based on thermal Williams-Comstock and micro-track models show that these two variations cause the transition center and the transition parameter to vary, thus affecting the transition response of the HAMR system.
2013 10th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology, 2013
Backoff algorithm is a technique to reduce packet collisions and to improve throughput efficiency... more Backoff algorithm is a technique to reduce packet collisions and to improve throughput efficiency in wireless local area network (WLAN). In this research, we propose a new backoff algorithm which is named Binary Exponential Increment Half Decrement (BEIHD) backoff algorithm. Furthermore, we introduce a new discrete Markov chain model for modeling the performance analysis of wireless local area network. A new model is called the Fixed Backoff stages and Fixed Contention windows (FBFC) technique. In FBFC scheme, the accuracy of the transmission probability parameter is derived from step by step procedure using the global balance equation concept in steady state condition. The saturated throughput efficiency of all backoff algorithms is compared under the same Physical layer (PHY) parameters and Medium Access Control (MAC) scheme in IEEE802.11a/b/g standards. Our numerical results show that the throughput performance of BEIHD backoff algorithm is better than the Binary Exponential Backoff (BEB) algorithm. Moreover, the distinction of BEIHD backoff algorithm is near the realistic system, and it can be implemented without to modify hardware in physical layer.
JURNAL INFOTEL
PhET is one of the most powerful and impressive simulator innovations, widely used in the STEM-ba... more PhET is one of the most powerful and impressive simulator innovations, widely used in the STEM-based learning process. Based on literature reviews, students are allowed to independently practice their skills and understanding of the material concept using this tool. PheT involves students in process competencies comprehensively and also provides a highly interactive virtual environment for STEM materials, including basic electronics, a sub-category of physics. This tool can also be easily accessed online at https://phet.colorado.edu/ or offline with a note that the user should download and install the application on a PC. An interesting question regarding this education tool is, "can PhET support basic electronics learning in Higher Education (HE)?" Numerous preliminary studies have not answered this question, which is associated with the technical aspect of the tool, because they only focused on the pedagogical aspect. Therefore, this research aims to fill this gap by exp...
Advanced Materials Research, 2013
The current data recording technology is approaching its capacity limit approximately 1 Tbit/in2 ... more The current data recording technology is approaching its capacity limit approximately 1 Tbit/in2 (terabits per square inch) known as superparamagnetic limit. Heat-assisted magnetic recording (HAMR) is one of the promising technologies that is being planned to be used as a new data recording technology to achieve the storage capacity beyond 1 Tbit/in2. In HAMR, the laser is applied to heat a magnetic medium during the writing process, which results in the unique transition characteristics if compared to a conventional system. This paper investigates the effects of thermal and cross-track variations to the transition characteristics (both transition center and transition parameter) of longitudinal HAMR systems. Experimental results indicate that the longitudinal HAMR system can withstand some amount of thermal and cross-track variations and still provides satisfactory system performance.
Computers, Materials & Continua
Visible Light Communication (VLC) technology is aggressive research for the next generation of co... more Visible Light Communication (VLC) technology is aggressive research for the next generation of communication. Currently, Radio Frequency (RF) communication has crowed spectrum. An Intelligent Transportation System (ITS) has been improved in the communication network for Vehicle-to-Vehicle (V2 V), Vehicle-to-Infrastructure (V2I), and Infrastructure-to-Vehicle (I2 V) by using the visible light spectrum instead of the RF spectrum. This article studies the characterization of Line-of-Sight (LOS) optical performance in an Outdoor Wireless Visible Light Communication (OWVLC) system employing a Multiple-Input Multiple-Output (MIMO) technique for I2 V communications in ITS regulations. We design the new configuration of the OWVLC-I2 V system, which is an alternative approach to communication for I2 V system at nighttime. The results show the Channel Impulse Response (CIR) of the LOS links in visible light communication for I2 V system in ITS by investigating the receiver on the vehicle moving along the coverage communication area. Furthermore, the OWVLC-I2 V system using the MIMO technique depicts the performance of throughput and Bit Error Rate (BER) vs. vehicle speed while the vehicle passes a street light.
White LED will be a dominant device for lighting in the near future through which we can have the... more White LED will be a dominant device for lighting in the near future through which we can have the luminance and data transmission simultaneously. An indoor wireless visible light communication system (IWVLC) describes the communication during the indoor applications. This paper presents an iterative receiver design for the IWVLC system and proposes the Soft-Output-Viterbi algorithm to equalize and detect the signal at the receiver of the IWVLC system which is based on the numerical simulation. The performance of the proposed algorithm is better than the conventional Viterbi algorithm in terms of the bit error rate. The simulation results unveil the performance of the proposed iterative algorithm where it can be seen that the BER comes out to be less at the same SNR (dB) as compared to the conventional ones even when the data rate is very high.
White LED will be a dominant device for lighting in the near future through which we can have the... more White LED will be a dominant device for lighting in the near future through which we can have the luminance and data transmission simultaneously. An indoor wireless visible light communication system (IWVLC) describes the communication during the indoor applications. This paper presents an iterative receiver design for the IWVLC system and proposes the SoftOutput-Viterbi algorithm to equalize and detect the signal at the receiver of the IWVLC system which is based on the numerical simulation. The performance of the proposed algorithm is better than the conventional Viterbi algorithm in terms of the bit error rate. The simulation results unveil the performance of the proposed iterative algorithm where it can be seen that the BER comes out to be less at the same SNR (dB) as compared to the conventional ones even when the data rate is very high.
In order to promote the extremely high areal density of perpendicular magnetic recording system t... more In order to promote the extremely high areal density of perpendicular magnetic recording system that is approaching its super-paramagnetic limit, the future technology known as heat-assisted magnetic recording (HAMR) has been proposed. Because perpendicular recording has many advantages over longitudinal recording, including high write field amplitude, sharp field gradient, well-aligned medium, less demagnetization field at transition, and so on. Thus the HAMR system is currently developed as extension of this perpendicular magnetic recording scheme. In this paper, we study the transition characteristics of perpendicular HAMR systems by varying some concerned parameters (e.g., peak temperature, write head gap, deep gap field, etc.) to optimize the performance of the HAMR system. Results show that the write head gap and the deep gap field are crucial parameters that are needed to be minimized so as to achieve high performance. In addition, we use each transition center in the simulat...
Optical design has played a key role in the optical wireless communications since it can enhance ... more Optical design has played a key role in the optical wireless communications since it can enhance the gains and the fields of view (FOVs) of the receivers without power consumption. In this paper, we propose an optical front end which is comprised of a multipleradius concave mirror, lens, and a detector so as to enlarge coverage areas of the optical wireless access point for an indoor scenario. The numerical investigation into performance of the proposed and the conventional optical concentrators has been conducted and presented. From the numerical studies, it is clear that although the proposed concentrator offers a smaller gain, it provides a significantly larger FOV in the indoor environment, resulting the substantially large coverage areas. As the proposed optical front end facilitates the ease of the manufacture and the broad coverage, its deployment at the uplink could reduce the installation cost.
Currently, a conventional magnetic recording system is approaching its storage capacity known as ... more Currently, a conventional magnetic recording system is approaching its storage capacity known as a super paramagnetic limit. Heat-assisted magnetic recording (HAMR) is one of new technologies that can achieve an areal density beyond this limit. In HAMR, the heat is applied in a medium during writing process resulting in unique transition characteristics if compared to a conventional system. This paper studies the effect of peak temperature and cross-track variations on the transition characteristics of a perpendicular HAMR system. Numerical results based on thermal Williams-Comstock and micro-track models show that these two variations cause the transition center and the transition parameter to vary, thus affecting the transition response of the HAMR system.
In near future, the conventional electric lamps will be replaced by the white light emitting diod... more In near future, the conventional electric lamps will be replaced by the white light emitting diode (LED) lamps because it offers many advantages such as low power consumption, long life time, small size, cool operation system. This work proposes the receiver design based on a partial-response maximumlikelihood technique for the indoor wireless visible light communication system, where a transmitter is placed on the ceiling, a receiver is on the table, and the signal transmission is based on the on-off keying intensity modulation. In addition, we also compare the performance between the proposed system and the conventional analog system in terms of bit-error rate at different data rates.
Currently, a conventional magnetic recording system is approaching its storage capacity known as ... more Currently, a conventional magnetic recording system is approaching its storage capacity known as a super paramagnetic limit. Heat-assisted magnetic recording (HAMR) is one of new technologies that can achieve an areal density beyond this limit. In HAMR, the heat is applied in a medium during writing process resulting in unique transition characteristics if compared to a conventional system. This paper studies the effect of peak temperature and cross-track variations on the transition characteristics of a perpendicular HAMR system. Numerical results based on thermal Williams-Comstock and micro-track models show that these two variations cause the transition center and the transition parameter to vary, thus affecting the transition response of the HAMR system.
In order to promote the extremely high areal density of perpendicular magnetic recording system t... more In order to promote the extremely high areal density of perpendicular magnetic recording system that is approaching its super-paramagnetic limit, the future technology known as heat-assisted magnetic recording (HAMR) has been proposed. Because perpendicular recording has many advantages over longitudinal recording, including high write field amplitude, sharp field gradient, well-aligned medium, less demagnetization field at transition, and so on. Thus the HAMR system is currently developed as extension of this perpendicular magnetic recording scheme. In this paper, we study the transition characteristics of perpendicular HAMR systems by varying some concerned parameters (e.g., peak temperature, write head gap, deep gap field, etc.) to optimize the performance of the HAMR system. Results show that the write head gap and the deep gap field are crucial parameters that are needed to be minimized so as to achieve high performance. In addition, we use each transition center in the simulation result to calculate nonlinear transition shift (NLTS) value to observe the dependence of NLTS on the distance between transitions and the relationship between write head gap. The results lead to the observation that the wide write head gap will increase the NLTS in the system, which degrade the overall system performance.
This paper proposes a product test time reduction. Our method employs statistical process control... more This paper proposes a product test time reduction. Our method employs statistical process control (SPC) and process capability analysis (PCA) as a tool. Algorithm verification was made upon the collected data of a specific product type. Box-Cox transformation has been applied to those data sets that hold non-normal distribution. Minitab software package was used as a mathematical analysis tool. The obtained result has convinced us the benefit of non-normal distribution to normal distribution data transformation. By applying the method to major time-consuming sub-processes, the test times could be reduced considerably. Proportionally required power can be saved. This study is of benefit not only in term of manufacturing cost reduction but also productivity enhancement.
Procedia Engineering
The current magnetic recording technology is approaching its theoretical boundary known as a supe... more The current magnetic recording technology is approaching its theoretical boundary known as a super-paramagnetic limit. Heat-assisted magnetic recording (HAMR) is one of the promissing technologies enabling higher recording capacity beyond this limit. In HAMR, the heat is applied in a medium during writing process resulting unique transition characteristics if compared to a conventional scheme. In this paper, we investigate the effect of different parameters, including the peak temperature, medium coercivity, a write head gap, a deep gap field, and a distance from pole to medium (or a fly height), on the transition characteristics of the longitudinal HAMR system. Numerical results indicate that there exists an optimal parameter setting which minimizes the transition enter and the transition parameter so as to provide high storage capacity.
ABSTRACT Currently, a conventional magnetic recording system is approaching its storage capacity ... more ABSTRACT Currently, a conventional magnetic recording system is approaching its storage capacity known as a super paramagnetic limit. Heat-assisted magnetic recording (HAMR) is one of new technologies that can achieve an areal density beyond this limit. In HAMR, the heat is applied in a medium during writing process resulting in unique transition characteristics if compared to a conventional system. This paper studies the effect of peak temperature and cross-track variations on the transition characteristics of a perpendicular HAMR system. Numerical results based on thermal Williams-Comstock and micro-track models show that these two variations cause the transition center and the transition parameter to vary, thus affecting the transition response of the HAMR system.
2013 10th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology, 2013
Backoff algorithm is a technique to reduce packet collisions and to improve throughput efficiency... more Backoff algorithm is a technique to reduce packet collisions and to improve throughput efficiency in wireless local area network (WLAN). In this research, we propose a new backoff algorithm which is named Binary Exponential Increment Half Decrement (BEIHD) backoff algorithm. Furthermore, we introduce a new discrete Markov chain model for modeling the performance analysis of wireless local area network. A new model is called the Fixed Backoff stages and Fixed Contention windows (FBFC) technique. In FBFC scheme, the accuracy of the transmission probability parameter is derived from step by step procedure using the global balance equation concept in steady state condition. The saturated throughput efficiency of all backoff algorithms is compared under the same Physical layer (PHY) parameters and Medium Access Control (MAC) scheme in IEEE802.11a/b/g standards. Our numerical results show that the throughput performance of BEIHD backoff algorithm is better than the Binary Exponential Backoff (BEB) algorithm. Moreover, the distinction of BEIHD backoff algorithm is near the realistic system, and it can be implemented without to modify hardware in physical layer.