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검색결과 4,829건 처리시간 0.03초

A 285-fsrms Integrated Jitter Injection-Locked Ring PLL with Charge-Stored Complementary Switch Injection Technique

  • Kim, Sungwoo;Jang, Sungchun;Cho, Sung-Yong;Choo, Min-Seong;Jeong, Gyu-Seob;Bae, Woorham;Jeong, Deog-Kyoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제16권6호
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    • pp.860-866
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    • 2016
  • An injection-locked ring phase-locked loop (ILRPLL) using a charge-stored complementary switch (CSCS) injection technique is described in this paper. The ILRPLL exhibits a wider lock range compared to other conventional ILRPLLs, owing to the improvement of the injection effect by the proposed CSCS. A frequency calibration loop and a device mismatch calibration loop force the frequency error to be zero to minimize jitter and reference spur. The prototype chip fabricated in 65-nm CMOS technology achieves a $285-fs_{rms}$ integrated jitter at GHz from the reference clock of 52 MHz while consuming 7.16 mW. The figure-of-merit of the ILRPLL is -242.4 dB.

The application of "bone window technique" using piezoelectric saws and a CAD/CAM-guided surgical stent in endodontic microsurgery on a mandibular molar case

  • Kim, Ukseong;Kim, Sunil;Kim, Euiseong
    • Restorative Dentistry and Endodontics
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    • 제45권3호
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    • pp.27.1-27.9
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    • 2020
  • Apical surgery for a mandibular molar is still challenging for many reasons. This report describes the applications of computer-guided cortical 'bone-window technique' using piezoelectric saws that prevented any nerve damage in performing endodontic microsurgery of a mandibular molar. A 49-year-old woman presented with gumboil on tooth #36 (previously endodontically treated tooth) and was diagnosed with chronic apical abscess. Periapical lesions were confirmed using cone-beam computed tomography (CBCT). Endodontic microsurgery for the mesial and distal roots of tooth #36 was planned. Following the transfer of data of the CBCT images and the scanned cast to an implant surgical planning program, data from both devices were merged. A surgical stent was designed, on the superimposed three-dimensional model, to guide the preparation of a cortical window on the buccal side of tooth #36. Endodontic microsurgery was performed with a printed surgical template. Minimal osteotomy was required and preservation of the buccal cortical plate rendered this endodontic surgery less traumatic. No postoperative complications such as mental nerve damage were reported. Window technique guided by a computer-aided design/computer-aided manufacture based surgical template can be considerably useful in endodontic microsurgery in complicated cases.

The Study of Sequential Lateral Solidification Process as a Function of Laser Intensity

  • Jang, Sung-Jin;Kim, Byoung-Joo;Kim, Hyun-Jae;Kang, Myung-Koo;Souk, Jun-Hyung;Kim, Do-Young;Suh, Chang-Ki;Dhungel, Suresh Kumar;Yi, Jun-Sin
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.679-682
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    • 2003
  • We report the suitable SLS (sequential lateral solidification) as a function of laser intensity. Precursor film is changed from 50nm to 100nm and is deposited on glass substrate by PECVD. We can find the suitable SLS length by changing the mask size. In this paper, we present the well-defined grain growth conditions as a function of laser intensity.

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Pulsed Ferrite Magnetic Field Generator for Through-the-earth Communication Systems for Disaster Situation in Mines

  • Bae, Seok;Hong, Yang-Ki;Lee, Jaejin;Park, Jihoon;Jalli, Jeevan;Abo, Gavin S.;Kwon, Hyuck M.;Jayasooriya, Chandana K.K.
    • Journal of Magnetics
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    • 제18권1호
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    • pp.43-49
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    • 2013
  • A pulsed ferrite magnetic field generator (FMFG) was designed for the use in the 1000 m long through-the-earth (TTE) communication system for mining disaster situations. To miniaturize the TTE system, a ferrite core having 10,000 of permeability was used for the FMFG. Attenuation of the magnetic field intensity from the FMFG (200-turn and 0.18 m diameter) was calculated to be 89.95 dB at 1000 m depth soil having 0.1 S/m of conductivity. This attenuation was lower than 151.13 dB attenuation of 1 kHz electromagnetic wave at the same conditions. Therefore, the magnetic-field was found to be desirable as a signal carrier source for TTE communications as compared to the electromagnetic wave. The designed FMFG generates the magnetic field intensity of $1{\times}10^{-10}$ Tesla at 1000 m depth. This magnetic field is detectable by compact magnetic sensors such as flux gate or magnetic tunneling junction sensor. Therefore, the miniature FMFG TTE communication system can replace the conventional electromagnetic wave carrier type TTE system and allow reliable signal transmission between rescuer and trapped miners.

COVID-19: Improving the accuracy using data augmentation and pre-trained DCNN Models

  • Saif Hassan;Abdul Ghafoor;Zahid Hussain Khand;Zafar Ali;Ghulam Mujtaba;Sajid Khan
    • International Journal of Computer Science & Network Security
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    • 제24권7호
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    • pp.170-176
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    • 2024
  • Since the World Health Organization (WHO) has declared COVID-19 as pandemic, many researchers have started working on developing vaccine and developing AI systems to detect COVID-19 patient using Chest X-ray images. The purpose of this work is to improve the performance of pre-trained Deep convolution neural nets (DCNNs) on Chest X-ray images dataset specially COVID-19 which is developed by collecting from different sources such as GitHub, Kaggle. To improve the performance of Deep CNNs, data augmentation is used in this study. The COVID-19 dataset collected from GitHub was containing 257 images while the other two classes normal and pneumonia were having more than 500 images each class. There were two issues whike training DCNN model on this dataset, one is unbalanced and second is the data is very less. In order to handle these both issues, we performed data augmentation such as rotation, flipping to increase and balance the dataset. After data augmentation each class contains 510 images. Results show that augmentation on Chest X-ray images helps in improving accuracy. The accuracy before and after augmentation produced by our proposed architecture is 96.8% and 98.4% respectively.

Resume Classification System using Natural Language Processing & Machine Learning Techniques

  • Irfan Ali;Nimra;Ghulam Mujtaba;Zahid Hussain Khand;Zafar Ali;Sajid Khan
    • International Journal of Computer Science & Network Security
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    • 제24권7호
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    • pp.108-117
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    • 2024
  • The selection and recommendation of a suitable job applicant from the pool of thousands of applications are often daunting jobs for an employer. The recommendation and selection process significantly increases the workload of the concerned department of an employer. Thus, Resume Classification System using the Natural Language Processing (NLP) and Machine Learning (ML) techniques could automate this tedious process and ease the job of an employer. Moreover, the automation of this process can significantly expedite and transparent the applicants' selection process with mere human involvement. Nevertheless, various Machine Learning approaches have been proposed to develop Resume Classification Systems. However, this study presents an automated NLP and ML-based system that classifies the Resumes according to job categories with performance guarantees. This study employs various ML algorithms and NLP techniques to measure the accuracy of Resume Classification Systems and proposes a solution with better accuracy and reliability in different settings. To demonstrate the significance of NLP & ML techniques for processing & classification of Resumes, the extracted features were tested on nine machine learning models Support Vector Machine - SVM (Linear, SGD, SVC & NuSVC), Naïve Bayes (Bernoulli, Multinomial & Gaussian), K-Nearest Neighbor (KNN) and Logistic Regression (LR). The Term-Frequency Inverse Document (TF-IDF) feature representation scheme proven suitable for Resume Classification Task. The developed models were evaluated using F-ScoreM, RecallM, PrecissionM, and overall Accuracy. The experimental results indicate that using the One-Vs-Rest-Classification strategy for this multi-class Resume Classification task, the SVM class of Machine Learning algorithms performed better on the study dataset with over 96% overall accuracy. The promising results suggest that NLP & ML techniques employed in this study could be used for the Resume Classification task.

3D Bioprinted GelMA/PEGDA Hybrid Scaffold for Establishing an In Vitro Model of Melanoma

  • Duan, Jiahui;Cao, Yanyan;Shen, Zhizhong;Cheng, Yongqiang;Ma, Zhuwei;Wang, Lijing;Zhang, Yating;An, Yuchuan;Sang, Shengbo
    • Journal of Microbiology and Biotechnology
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    • 제32권4호
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    • pp.531-540
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    • 2022
  • Due to the high incidence of malignant melanoma, the establishment of in vitro models that recapitulate the tumor microenvironment is of great biological and clinical importance for tumor treatment and drug research. In this study, 3D printing technology was used to prepare GelMA/PEGDA composite scaffolds that mimic the microenvironment of human malignant melanoma cell (A375) growth and construct in vitro melanoma micro-models. The GelMA/PEGDA hybrid scaffold was tested by the mechanical property, cell live/dead assay, cell proliferation assay, cytoskeleton staining and drug loading assay. The growth of tumor cells in two- and three-dimensional culture systems and the anti-cancer effect of luteolin were evaluated using the live/dead staining method and the Cell Counting Kit-8 (CCK-8) method. The results showed a high aggregation of tumor cells on the 3D scaffold, which was suitable for long-term culture. Cytoskeleton staining and immunofluorescent protein staining were used to evaluate the degree of differentiation of tumor cells under 2D and 3D culture systems. The results indicated that 3D bioprinted scaffolds were more suitable for tumor cell expansion and differentiation, and the tumor cells were more aggressive. In addition, luteolin was time- and dose-dependent on tumor cells, and tumor cells in the 3D culture system were more resistant to the drug.

Resist 표면 거칠기 예측을 위한 전자빔 리소그라피 시뮬레이션에 관한 연구 (A Study on Electron-beam Lithography Simulation for Resist Surface Roughness Prediction)

  • 김학;한창호;이기용;이우진;전국진
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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    • pp.45-48
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    • 2002
  • This paper discusses the surface roughness of negative chemically amplified resists, SAL601 exposed by I-beam direct writing. system. Surface roughness, as measured by atomic force microscopy, have been simulated and compared to experimental results. Molecular-scale simulator predicts the roughness dependence on material properties and process conditions. A chemical amplification is made to occur in the resists during PEB process. Monte-Carlo and exposure simulations are used as the same program as before. However, molecular-scale PEB simulation has been remodeled using a two-dimensional molecular lattice representation of the polymer matrix. Changes in surface roughness are shown to correlate with the dose of exposure and tile baking time of PEB process. The result of simulation has a similar tendency with that of experiment.

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High Color Depth Driver LSIs for TFT-LCDs

  • Jang, Chul-Sang;Yoo, Juhn-Suk;Lee, Dong-Hoon;Kim, Jong-Hoon;Chung, In-Jae;Kim, Jin-Ho;Choi, Jin-Chul;Lee, Jae-Sic;Kim, Seon-Yung;Kwon, Oh-Kyong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.657-658
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    • 2005
  • We designed 10bit source driver LSI, then the high color depth and the low power consumption are realized thru it. It is adopted mini-LVDS receiver with high speed data transmission and good data recovery performance, Hybrid type DAC to reduce decoder size and OP-AMP with low power consumption and high slew rate. In addition we show our results of the 10-bit gray scale TFT-LCD source driver for 42inch diagonal size and WXGA resolution TFT-LCD TV applications.

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Neuron Circuit Using a Thyristor and Inter-neuron Connection with Synaptic Devices

  • Ranjan, Rajeev;Kwon, Min-Woo;Park, Jungjin;Kim, Hyungjin;Park, Byung-Gook
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제15권3호
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    • pp.365-373
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    • 2015
  • We propose a simple and compact thyristor-based neuron circuit. The thyristor exhibits bi-stable characteristics that can mimic the action potential of the biological neuron, when it is switched between its OFF-state and ON-state with the help of assist circuit. In addition, a method of inter-neuron connection with synaptic devices is proposed, using double current mirror circuit. The circuit utilizes both short-term and long-term plasticity of the synaptic devices by flowing current through them and transferring it to the post-synaptic neuron. The double current mirror circuit is capable of shielding the pre-synaptic neuron from the post synaptic-neuron while transferring the signal through it, maintaining the synaptic conductance unaffected by the change in the input voltage of the post-synaptic neuron.