Myint, Lin Min
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Myint, Lin Min
Alternative Name
Myint, L. M.
Myint, L.
Myint, Lin Min Min
Myint, Lin M.
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Email
linminmin.my@kmitl.ac.th
17 results
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Item type:Publication, Effects of Equatorial Plasma Bubbles over Real-Time Kinematic Positioning in Low-Latitude Region(2023-01-01); ; ; Saito, SusumuEquatorial plasma bubbles (EPBs) refer to ionospheric irregularities in low-latitude regions, commonly observed after sunset. They originate at the magnetic equator and then potentially spread to mid-latitude region. As cm-level positioning techniques are increasingly important to various segments of society, the performance degradation of these systems due to EPB at low latitudes needs to be investigated. In this work, we analyze the EPB effects on the performances of real-time kinematic (RTK) positioning at the short, medium, and long baselines at low-latitude stations in Thailand. The low-latitudes local ionospheric disturbances such EPBs are shown to degrade the positioning accuracy of RTK in different seasons in 2022. It is found that the positioning errors are higher during the disturbance periods and more severe at the long baselines than the shorter ones, especially during the equinoctial months. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A bit-flipping technique based on 2D modulation constraint in BPMR systems(2018-10-24); Inter-track interference (ITI) cancelation is one of the considerable challenges for high areal density (AD) magnetic recording such as in bit-patterned media recording (BPMR) systems. In literature, the two-dimensional (2D) modulation codes have been proposed to cancel the ITI effect [1, 2] which can efficiently improve the overall system performance, e.g., a rate-5/6 2D modulation code [2]. Although the rate-5/6 modulation code ensures that the readback signal of the center track will not be corrupted by severe ITI; however, both the upper and lower tracks can still be interfered by their sidetracks. To improve this shortcoming; therefore, we propose the bit-flipping technique that performs together with the rate-5/6 2D modulation code. Here, the relationship between the data encoding condition and soft-information obtained from the soft output Viterbi algorithm (SOVA) detector is utilized to be a criterion for flipping the ambiguous data bits. Simulation results indicate that the proposed system is better than the conventional coded system under with/without media noise and track mis-registration. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Study of Detectors with Noise Predictor for High Areal Density BPMR Systems(2019-04-10); In this paper, we study the performance of Viterbi detectors embedded with noise predictor for the 2-D interference channel of high areal density bit patterned media recording (BPMR) system. After the readback signal is processed by a equalizer, the received signal at the input of detector is corrupted by the colored/correlated noise. Therefore, the noise whitening process using a noise predictor is required to improve the performance of the detector. When the noise predictor is incorporated into the detector, it needs to extend the structure of trellis in the detector. For the 2-D interference channel of BPMR system, the complexity of the detector will grow beyond the practical level. Therefore, we design a detector embedded by a noise prediction technique without extending the trellis. In the proposed technique, the most likely noise samples generated from the branch metric calculation are stored along the surviving path of the trellis in Viterbi algorithm. The proposed technique requires less number of memory and arithmetic operations at each state of the trellis compared to conventional technique. We consider both finite impulse response (FIR) filter and infinite impulse response (IIR) filter for the noise prediction filter. The simulation results show that the proposed noise prediction can improve the performance of detector, especially for the high areal density at 4 Tbit/in<sup>2</sup>. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Ionospheric Scintillation Prediction Using Decision Tree and Rainforest Techniques(2024-01-01); ; Saito, SusumuThe ionosphere contains electron density variation. When radio signals transmitted from global navigation satellite systems (GNSS) pass through such medium, additional delays are added. With ionospheric irregularity, fluctuation in GNSS signals known as scintillation are often observed resulting in reduced number of tracked satellites then degrade positioning performances. At present, scintillation is considered random, hence, the ability to detect or predict such phenomenon is crucial to efficient system operation. In this research, we design machine learning algorithm for scintillation prediction. Both Decision Tree (DT) and Random Decision Forest (RF), are implemented to predict daily ionospheric scintillation at King Mongkut's Institute of Technology Ladkrabang (KMITL) station in Thailand (13.73 ° E, 100.77° N). The rate of total electron content change index (ROTI) is also used. Modeling is carried out for four months in March (equinox), June (solstice), September (equinox), and December (solstice) in 2022, representing different seasons in space weather study. The prediction results are evaluated using the S 4 index observations at KMITL station and then compared between DT and RF methods. The designed model has a high potential for scintillation prediction. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Track mis-registration detection using correlation functions in magnetic recording(2012-12-01); ; Track mis-registration (TMR) causes the asymmetric inter-track interference which degrades the system performance. In this work, we propose a TMR detection method based on the cross-correlation functions in bit patterned media (BPM) recording systems. Firstly, the coefficients of the channel are predicted with the cross-correlation functions between the readback signals and the recorded bit sequences on the main track as well as the interfering tracks. Using the ratio of the channel coefficients, the presence and direction of TMR and can be predicted more accurately. © 2012 DSI. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Equatorial Plasma Bubble Detection by Support Vector Machine at Chumphon Station, Thailand(2022-01-01); ; ; Hozumi, KornyanatEquatorial Plasma Bubble (EPB) is a phenomenon in which depletion of plasma density occurs in the ionosphere particularly in the equatorial region. It can degrade the performances of the navigation system and satellite communication. In this work, we analyze EPB based on the very-high frequency (VHF) radar images at Chumphon station, Thailand. Then an EPB detection system using the support vector machine (SVM) technique is developed, and the accuracies of the systems using different kernels: linear kernel, the polynomial kernel, the radial basic functions kernel (RBF), and the sigmoid kernel are compared. Among the different kernels, we find that the RBF kernel gives the highest accuracy in prediction at 86.67 percent. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A TMR mitigation method with 3-track data detection for multi-track multi-head BPMR system(2017-08-10); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, An early termination technique of polar codes for IR-HARQ scheme(2020-10-08); ; In this work, we focus on polar codes in mobile communication systems where a retransmission strategy, namely, the incremental redundancy hybrid automatic repeat request (IR-HARQ) scheme, is performed. We propose an early termination (ET) of polar codes using the interleaved cyclic redundancy check (CRC) codes and the parity check (PC) codes. The parity-check equations of CRC and PC codes are used to detect the incorrectly decoded bits during the polar decoding. The simulation results verify that the proposed ET techniques can detect the erroneous bits in initial transmission and retransmission. The proposed technique provides the ET rate about 4-90%, and the block error rate (BLER) performance degradation is less than 2 dB. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A simple crossover-based coding technique for ITI mitigation in bit-patterned media recording(2014-02-12); ; Kovintavewat, PiyaDue to bits being recorded at ultra-high density, a bit-patterned media recording (BPMR) system is faced with two-dimensional (2D) interference, namely inter-symbol interference (ISI) and inter-track interference (ITI), which degrades the overall performance of a recording system. One solution to avoid the 2D interference effect is to apply a modulation code to forbid some specific data patterns leading to severe 2D interference. Nonetheless, this method usually requires either many redundant bits or additional memory. Thus, this paper proposes a simple technique to encode an input data sequence to mitigate the 2D interference effect before recording them onto a magnetic medium. The proposed technique shows the improvement in reducing complexity and additional memory using a crossover-based technique when comparing to other existing methods. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Interleaved CRC codes for polar codes with partitioned list decoding(2021-05-19); ; In this work, we propose an interleaved cyclic redundancy check (CRC) code for the partitioned successive cancellation list (PSCL) decoder of polar codes. Since the CRC bits are interleaved into each partition of the PSCL decoder, the CRC bit can be used to eliminate the unreliable codewords. We examine that the performances of the PSCL decoder are influenced by the first-row weight of the parity-check matrix of interleaved CRC code. Therefore, the parity-check matrix of interleaved CRC code must be constructed by minimizing the first-row weight. The simulation results show that the interleaved CRC with a smaller weight can provide better error-correcting performance than the interleaved CRC with a larger weight.