• Electrical & Electronic Materials
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• v.8 no.5
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• pp.633-639
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• 1995

Dropouts in magnetic media are a primary quality deficiency which is detrimental to magnetic signal quality and thus the major impediment to error-free recording, especially in high density digital recorders. The specific form of defects and causes found to be responsible for signal dropouts occurring in magnetic tape were studied. Dropout occurred when the RF signal falls to low level due to the various types of surface defects. However, the fall in the level of the RF signal in gravure roll coated tapes was most often caused by foreign particles adhering to the magnetic tape. It was also shown from the present study that scattered particles trapped under the tape surface or put on the top can lift it as it crosses the head, creating a spherical tent shaped defect and causing a temporary signal drop. Dropout producing substances were identified through optical and microchemical analyses. The results were correlated with measured electrical signal losses combined with analytical microscopy to clarify source identification of defects.

• Journal of the Semiconductor & Display Technology
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• v.19 no.4
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• pp.65-70
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• 2020

CNN's technologies that represent emotional detection include primitive CNN algorithms, deployment normalization, and drop-off. We present the methods and data of the three experiments in this paper. The training database and the test database are set up differently. The first experiment is to extract emotions using Batch Normalization, which complemented the shortcomings of distribution. The second experiment is to extract emotions using Dropout, which is used for rapid computation. The third experiment uses CNN using convolution and maxpooling. All three results show a low detection rate, To supplement these problems, We will develop a deep learning algorithm using feature extraction method specialized in image processing field.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.6
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• pp.1154-1162
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• 2016

This paper proposes a fast-transient digital LDO(Low dropout) regulator with binary-weighted current control technique. Conventional digital LDO takes a long time to stabilize the output voltage, because it controls the amount of current step by step, thus ringing problem is generated. Binary-weighted current control technique rapidly stabilizes output voltage by removing the ringing problem. When output voltage reliably reaches the target voltage, It added the FRZ mode(Freeze) to stop the operation of digital LDO. The proposed fast response digital LDO is used with a slow response DC-DC converter in the system which rapidly changes output voltage. The proposed digital controller circuit area was reduced by 56% compared to conventional bidirectional shift register, and the ripple voltage was reduced by 87%. A chip was implemented with a $0.18{\mu}F$ CMOS process. The settling time is $3.1{\mu}F$ and the voltage ripple is 6.2mV when $1{\mu}F$ output capacitor is used.

• Journal of Biomedical Engineering Research
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• v.45 no.4
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• pp.162-172
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• 2024

To analyse the overall research trends in digital therapeutics, this study conducted a quantitative bibliometric analysis of articles published in the last 10 years from 2014 to 2023. We extracted bibliographic information of studies related to digital therapeutics from the Web of Science (WOS) database and performed publication status, citation analysis and keyword analysis using R (version 4.3.1) and VOSviewer (version 1.6.18) software. A total of 1,114 articles were included in the study, and the annual publication growth rate for digital therapeutics was 66.1%, a very rapid increase. "health" is the most used keyword based on Keyword Plus, and "cognitive-behavioral therapy", "depression", "healthcare", "mental-health", "meta-analysis" and "randomized controlled-trial" are the research keywords that have driven the development and impact of digital therapeutic devices over the long term. A total of five clusters were observed in the co-occurrence network analysis, with new research keywords such as "artificial intelligence", "machine learning" and "regulation" being observed in recent years. In our analysis of research trends in digital therapeutics, keywords related to mental health, such as depression, anxiety, and disorder, were the top keywords by occurrences and total link strength. While many studies have shown the positive effects of digital therapeutics, low engagement and high dropout rates remain a concern, and much research is being done to evaluate and improve them. Future studies should expand the search terms to ensure the representativeness of the results.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.123-127
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• 2021

Millimeter-wave tracking radars should be operated in various environmental restrictions, thus they demand more computing power and smaller size compared to conventional tracking radars. This paper presents the design and implementation of the compact power supply for millimeter-wave tracking radar applications. To meet requirements of low voltage/high current and voltage accuracy for FPGA/DSP digital circuits, Point of Load (POL) converters are used in order to enhance power density and system efficiency. LDO (Low Dropout) is applied for the output voltage under the light load condition, then the single-input-multi-output power supply with max power of 375 W and 8 outputs is developed. The proposed power supply achieves output voltage accuracy of ±2 % and noise level of <50 mVpp % under full load conditions.

• Journal of Positioning, Navigation, and Timing
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• v.4 no.3
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• pp.115-122
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• 2015

Global Positioning System (GPS) is used in various fields such as communications systems, transportation systems, e-commerce, power plant systems, and up to various military weapons systems recently. However, GPS receiver is vulnerable to jamming signals as the GPS signals come from the satellites located at approximately 20,000 km above the earth. For this reason, various anti-jamming techniques have been developed for military application systems especially and it is also required for commercial application systems nowadays. In this paper, we proposed a dual-channel Global Navigation Satellite System (GNSS) RF ASIC for digital pre-correlation anti-jam technique. It not only covers all GNSS frequency bands, but is integrated low-gain/attenuation mode in low-noise amplifier (LNA) without influencing in/out matching and 14-bit analogdigital converter (ADC) to have a high dynamic range. With the aid of digital processing, jamming to signal ratio is improved to 77 dB from 42 dB with proposed receiver. RF ASIC for anti-jam is fabricated on a 0.18-μm complementary metal-oxide semiconductor (CMOS) technology and consumes 1.16 W with 2.1 V (low-dropout; LDO) power supply. And the performance is evaluated by a kind of test hardware using the designed RF ASIC.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.29 no.1
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• pp.4-12
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• 2020

Recently, according to the concept of minimal invasive, there have been many opportunities for restoration treatment with porcelain laminate veneers that are less invasive and can ideally improve esthetics. Patients also visit the laminate well, and patients also want to reduce the amount of teeth cut, so the choice of the entire trimming crown is decreasing. Therefore, various techniques of laminate are required. Most dental clinicians seem to have negative images of laminates such as risk of fracture, margin pigmentation and dropout. However, this situation is due to incorrect adhesion manipulation and lack of inspection of the occlusal relationship, and there is no problem with the Porcelain Laminate Veneer itself. The purpose and scope of adaptation leading to the success of porcelain laminate veneer will be introduced.

• Journal of Biomedical Engineering Research
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• v.19 no.6
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• pp.571-575
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• 1998

One of the most significant features of diagnostic ultrasonic instruments is to provide real time information of the soft tissues movements. Echocardiogram has been widely used for diagnosis of heart diseases since it is able to show real time images of heart valves and walls. However, the currently used ultrasonic images are deteriorated due to presence of speckle noises and image dropout. Therefore, it is very important to develop a new technique which can enhance ultrasonic images. In this study, a technique which extracts enhanced binary images in echocardiograms was proposed. For this purpose, a digital moving image file was made from analog echocardiogram, then it was stored as 8-bit gray-level for each frame. For an efficient image processing, the region containing the heat septum and tricuspid valve was selected as the region of interest(ROI). Image enhancement filters and morphology filters were used to reduce speckle noises in the images. The proposed procedure in this paper resulted in binary images with enhanced contour compared to those form the conventional threshold technique and original image processing technique which can be further implemented for the quantitative analysis of the left ventricular wall motion in echocardiogram by easy detection of the heart wall contours.