Sokjabok, Siwakon

Preferred name

Sokjabok, Siwakon

Alternative Name

Sokjabok, S.

Main Affiliation

KMITL Prince of Chumphon Campus

siwakon.so@kmitl.ac.th

Now showing 1 - 8 of 8

Some of the metrics are blocked by your
consent settings
Symbol-flipping method for block decoding in bit-patterned magnetic recording
(2021-05-19)
Sokjabok, Siwakon
;
Mattayakan, Mutita
;
Warisarn, Chanon
;
Koonkarnkhai, Santi
;
Kovintavewat, Piya
Bit-patterned magnetic recording (BPMR) technology can provide an areal density (AD) up to 15 Terabit per square inch (Tb/in2). However, the consequence of an increased AD results in severe inter-symbol interference (ISI) and inter-track interference (ITI). In practice, a run-length limited (RLL) code can be used to alleviate this problem. Therefore, this research proposes a symbol-flipping method in an iterative detection scheme between a soft-output Viterbi algorithm (SOVA) detector and an RLL decoder to help reduce errors resulting from these two interferences in a BPMR system. Simulation results reveal that the proposed system performs better than the same system architecture without the symbol-flipping method by 0.5 decibels at an AD of 5 Tb/in2.
Some of the metrics are blocked by your
consent settings
Codeword design of a Rate-5/6 for single-reader two-track reading in BPMR systems
(2021-05-19)
Mattayakan, Mutita
;
Sokjabok, Siwakon
;
Warisarn, Chanon
At present, the information storage demand of hard disk drive (HDD) was dramatically increasing every year. However, an increase of an areal density (AD) for bit-patterned media recording (BPMR) seems to be crucial for HDD industry. One of the main problems of BPMR system is two-dimensional interference effect that composes of inter-track interference (ITI) and inter-symbol interference (ISI), which still be the main challenge that we have to flounder to continuously enhance the efficiency of magnetic recording system. Therefore, this paper proposes a rate-5/6 2D modulation code to evolve bit error rate (BER) efficiency of a staggered single-reader two-track reading (SRTR) based BPMR systems. We select all 32 codewords from all 64 considered patterns according to the statistics principle considering. The first 32 patterns that provide the least error-bit number will then be defined as our proposed codewords. These selected patterns can efficiently avoid the forbidden patterns that means it is going to radically suppress both ISI and ITI effects. We simply encode by using a look-up table, while we use the Euclidean distance concept to recover user bits in the decoding process. From the simulation, we found that the proposed method shows a better BER efficiency than both the uncoded and conventional recording systems. Even we add more media noises, this proposed system still provides us with a better performance. Moreover, SRTR scheme offers us more satisfactory capability than the conventional recording systems.
Some of the metrics are blocked by your
consent settings
Study of CNN-Based Data Detection in Dual-Layer Bit-Patterned Magnetic Recording Systems
(2025-01-01)
Sangthong, Siraphop
;
Sokjabok, Siwakon
;
Khametong, Anawin
;
Warisarn, Chanon
This paper introduces an innovative data detection system that utilizes convolutional neural networks (CNNs) for dual-layered bit-patterned magnetic systems. Using a mutual-information CNN architecture, the proposed system tackles the challenge of decoding overlapping readback signals from upper and lower layers. The sliding window detection schemes are implemented with input lengths of 6 (2×3) and 14 (2×7) bits, processing oversampled readback signals from a dataset of 1,000,000 bits. Simulation results conducted over a signal-to-noise ratio range of 10 to 24 dBs indicate that the CNN model with a larger input window significantly outperforms smaller input models and conventional partial response maximum likelihood detectors in terms of bit error rate. These findings illustrate the effectiveness of CNN-based detection in enhancing classification accuracy under high-noise conditions, paving the way for future ultra-high-density magnetic recording systems.
Some of the metrics are blocked by your
consent settings
Analysis of liquids conductivity using hall effect sensor based on electromagnetic field properties
(2017-11-10)
Sokjabok, Siwakon
;
Sriratana, Witsarut
;
Satthamsakul, Sutham
This paper presents a new methodology of analyzing liquid conductivity via the Hall Effect sensor based on electrochemical properties. Two different magnetic field cores with the same coil length (10 m, AWG 31) were studied, namely ferrite solenoid cores and toroidal iron powder cores (T131-26). The magnetic field generated by both type of cores was then used to generate a Hall voltage with the cores ratios of 1 : 1. The output Hall voltage is, in turn, sent through a microcontroller, together with a 10 bit converter for real time data analysis. The magnetic-field density of the solenoid for analyzing the conductivity of brine is 31 mT for solenoid, and 10.74 mT for toroid cores, respectively. Results from other materials are compared to the reference conductivity values of salt solution, which amounts to 16.211 mS/cm when assessed with the solenoid core, and 16.406 mS/cm when assessed with the toroid core.
Some of the metrics are blocked by your
consent settings
Experimental study on differentiating between natural honey and honey glucose syrup by using hall effect sensor
(2018-01-01)
Sriratana, Witsarut
;
Sokjabok, Siwakon
;
Sriratana, Lerdlekha
This study presents the application of Hall Effect sensor for differentiating the combination of liquids based on electrical conductance. Electromagnetic field was generated from wire (AWG 31) bound on high frequency magnetic core namely Toroidal iron power (T131-26) or C-shape Toroidal core. In this study, the electrochemical cell was fixed at 0.09375 cm<sup>-1</sup> there were 10 samples of several liquid types for testing. Hall Effect sensor was designed to place with high frequency magnetic cores bound by 310-turns wire. From experiment using electromagnetic field generated by C-shape Toroidal core, it can be observed that the samples of natural honey from Germany (J) and sugar substitute for diabetics (I) could be distinguished by considering output voltage of Hall Effect sensor (V<inf>H</inf>) and electrical conductance. The output voltage and the electrical conductance from measurement of natural honey (J) were 3.037 V and 0.941 mS.T, respectively while those from measurement of sugar substitute (I) were 3.030 V and 0.938 mS.T, respectively. Moreover, it can be noted that this methodology could be applied for measuring electrical conductance of several liquid types due to the relationships of output voltage of Hall Effect sensor and electrical conductance of liquid. However, only C-shape Toroidal core was used in this study due to the appropriate generation of electromagnetic field for differentiating both sample liquid types with ± 1.83% of error for natural honey and ± 1.51% of error for sugar substitute from 195 times of repetitive measurement.
Some of the metrics are blocked by your
consent settings
Fabrication of Eco-Friendly Pineapple Leaf Fiber-Based Vegan Leather for Environmental Sustainability
(2026-01-20)
Srisang, Siriwan
;
Kunyuan, Jumpon
;
Hutangkoon, Thunyanat
;
Eiangmee, Orranat
;
Maikaew, Jatuphat
The environmental impact of synthetic leather production has raised global concerns due to its reliance on petroleum-based polymers and poor biodegradability. Therefore, the development of sustainable, eco-friendly alternatives using renewable resources has become increasingly important. A biodegradable vegan leather was developed from natural rubber and pineapple leaf fibers (PALF), with properties analyzed using Response Surface Methodology (RSM). The effects of fiber content (X1), compression time (X2), and compression temperature (X3) were studied on biodegradation (Y1), water absorption (Y2), and tensile strength (Y3). Results showed that all three factors significantly influenced Y1, with the predictive model demonstrating high reliability (R > 90%). The optimum condition for Y1 was X1 = 3.0 g, X2 = 70.0 min, and X3 = 110.0 C, yielding a maximum predicted biodegradation of about 21%. In contrast, the models for Y2 and Y3 were statistically unreliable (P > 0.05) due to low RÂ² values. However, Y2 passed the lack-of-fit test, suggesting an adequate model form, while Y3 failed (P < 0.05), indicating an inadequate prediction model. These findings suggest future experiments should narrow factor ranges and include additional control variables to improve the predictability of Y2 and Y3. Despite these limitations, the study highlights a sustainable alternative to conventional synthetic leather, aligning with circular economy principles and supporting the United Nations Sustainable Development Goals (SDGs). Importantly, the process is resource-efficient: from 1 kg of pineapple leaves, only 20 g of fibers is obtained, and just 75 g of PALF was used in 15 experimental runs. This minimal material requirement underscores the potential of the approach for sustainable production, while highlighting potential applications in sustainable fashion, packaging, and eco-friendly product design.
Some of the metrics are blocked by your
consent settings
Modified 2D Viterbi Algorithm using 2D Modulation Encoding Constraints in BPMR Systems
(2020-06-01)
Sokjabok, Siwakon
;
Warisarn, Chanon
;
Koonkarnkhai, Santi
;
Lee, Jaejin
The severity of inter-symbol interference (ISI) and inter-track interference (ITI) effects caused by the reduction of the spacing between bit islands in the along- and across-track directions to acquire ultra-high areal densities (ADs) is the main problem in bit-patterned magnetic recording (BPMR) systems. We call these two effects as two-dimensional (2D) interference, which can degrade the overall system performance. Practically, a one-dimensional (1D) modulation code, e.g., run-length limited (RLL) code, is essentially utilized to prevent the severe ISI effect. The use of 2D detectors is also one of the important ways to cope with the severe ITI; however, its complexity is quite high. To avoid the severe ITI effect and complex 2D detectors; therefore, we propose to apply the 1D RLL code as the 2D modulation code. Then, the 2D modulation encoding constraint is employed to reduce the number of states and branches in the trellis of the proposed modified 2D Viterbi detector. Simulation results reveal that the proposed detector not only delivers a lower complexity but also provides superior bit error rate gain, especially at ultra-high ADs and/or large location fluctuation.
Some of the metrics are blocked by your
consent settings
Simple Soft-Information Developers Based on Parallel Detection Scheme in Bit-Patterned Media Recording (BPMR) Systems
(2021-06-27)
Mattayakan, Mutita
;
Sokjabok, Siwakon
;
Warisam, Chanon
Among the alternate ultra-high density data storage technologies, bit-patterned media recording (BPMR) is one of the mentioned technologies that was proposed to achieve a higher density. Due to the closeness between the magnetic islands, so the readback sequences are disrupted from the effect of two-dimensional (2D) interference, which includes both intersymbol interference (ISI) and intertrack interference (ITI). In this paper; therefore, we propose the simple and effective soft-information developers (SIDs) to improve the soft-information that are obtained from both vertical and horizontal detectors. An optimal weight was optimized under the BPMR channel before multiplying with the horizontal soft-information. The proposed SIDs and conventional 2D detector's performances were carefully compared in the terms of BER. The results show that our proposed methods achieve a gain of approximately 8 dB at a BER of 10-3.

Sokjabok, Siwakon

Filters

Settings

Sort By

Results per page