• Journal of Convergence for Information Technology
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• v.12 no.2
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• pp.47-53
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• 2022

Recently, with the change of the intelligent security paradigm, study to apply various information generated from various information security systems to AI-based anomaly detection is increasing. Therefore, in this study, in order to convert log-like time series data into a vector, which is a numerical feature, the CBOW and Skip-gram inference methods of deep learning-based Word2Vec model and statistical method based on the coincidence frequency were used to transform the published ADFA system call data. In relation to this, an experiment was carried out through conversion into various embedding vectors considering the dimension of vector, the length of sequence, and the window size. In addition, the performance of the embedding methods used as well as the detection performance were compared and evaluated through GRU-based anomaly detection model using vectors generated by the embedding model as an input. Compared to the statistical model, it was confirmed that the Skip-gram maintains more stable performance without biasing a specific window size or sequence length, and is more effective in making each event of sequence data into an embedding vector.

• Journal of the Korean Data and Information Science Society
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• v.25 no.1
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• pp.177-185
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• 2014

Under bivariate normal distribution assumptions, the interaction and quadratic terms are needed in the logistic regression model with two predictors. However, depending on the correlation coefficient and the variances of two conditional distributions, the interaction and quadratic terms may not be necessary. Although the need for these terms can be determined by comparing the two scatter plots, it is not as useful for interaction terms. We explore the structure and usefulness of the 3-D residual plot as a tool for dealing with interaction in logistic regression models. If predictors have an interaction effect, a 3-D residual plot can show the effect. This is illustrated by simulated and real data.

• Journal of the Korea Convergence Society
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• v.7 no.1
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• pp.9-15
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• 2016

In this paper, we describe the design of a high speed data acquisition system(DAS) with STM32 processor based on Cortex-M4. The system is used for the sensor devices to collect raw data on production lines at factory and send them to the servo computer in real time. The system is designed for multi functions with universal asynchronous receiver and transmitter(UART), analog to digital converter(ADC), digital to analog converter(DAC), and general purpose input output(GPIO). those are well tested for various data acquisition and high speed motor control in real time.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1061-1066
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• 2012

A digital memory has been widely used as a device for storing information due to its reliable, fast and relatively simple control circuit. However, the storage of the digital memory will be limited by the inablility to make smaller linewidths. One way to dramatically increase the storeage capability of the memory is to change the type of stored data from digital to analog. The analog memory fabricated in a standard single poly 0.6um CMOS process has been developed. Single cell and adjacent circuit block for programming have been designed and characterized. Applications include low-density non-volatile memory, control of redundancy in SRAM and DRAM memories, ID or security code registers, and image and sound memory.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3702-3707
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• 2009

In this paper, a new approximated MAP algorithm for soft bit decision from QAM symbols is proposed for Gray Coded QAM signals, based on the Max-Log-MAP and a Gray coded QAM signal can be separated into independent two Gray coded PAM signal, M-PAM on I axis with M symbols and N-PAM on Q axis with N symbols. The Max-Log-MAP used distance comparisons between symbols to get the soft bit decision instead of mathematical exponential or logarithm functions. But in accordance with the increase of the number of symbols, the number of comparisons also increase with high complexity. The proposed algorithm is used with the Euclidean distance and constituted with plain arithmetic functions, thus we can know intuitively that the algorithm has low implementing complexity comparing to conventional ones.

• The Journal of the Acoustical Society of Korea
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• v.9 no.3
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• pp.48-55
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• 1990

We analyze the effect of second-order sampling on estimating the mean frequency of the Doppler signal. In order to reduce the sampling frequency of analogue-to-digital converter, it is possible to obtain the Doppler signal by sampling the radio frequency echo signal with the low frequence of $4f_0$/5 or $4f_0$/9 instead of $4f_0$, where $f_0$ is the center frequency of the transmitted signal. The computer simulation and experiments show that if the narrowband signal is transmitted as is usual in the Doppler system, the error of the mean frequency estimates due to the low sampling frequency is negligible.

• Journal of Biomedical Engineering Research
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• v.7 no.1
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• pp.59-66
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• 1986

A prototype ultrasound sector B-scanner has been developed where the front-end hardware refers to all the necessary circuits for transmitting the ultrasound pulses into the human body and receiving the reflected echo signals from it. The front-end hardware can generally be divided into three parts, i.e., a pulse generator for insonification, a receiver which is responsible for processing of low-level analog signals, and a steering controller for driving the mechanical sector probe whose functions and design concepts are described in this paper. The front-end hardware is implemented which incorporates the following features: improvement of the axial resolution using a circuit which reduces the ring-down time, flexibility of generating time-gain compensation curve, and adoption of a one-chip microcomputer for generating the rate pulses based on the sensor output waveforms.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.322-326
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• 2009

본 연구는 지열원식 냉난방 히트펌프 시스템의 상태를 실시간으로 감시하고 열 성능을 실시간으로 평가할 수 있도록 한 지열원식 냉난방 히트펌프 시스템의 상태 감시 및 열 성능 평가 방법에 관한 것으로서, 이러한 본 연구는, 프로그램 실행을 통하여 측정 간격이 설정되고, 다이얼로그 박스 상에서 시스템 개요, 공사개요, 히트펌프설비개요, 지열루핑 설비개요, 버퍼탱크, 건물개요 등을 입력받은 후 시스템의 개통도 이미지 파일프로그램 로딩과 각종 계측기를 통해 전기적인 데이터의 취득 기능 등의 데이터측정 준비를 위한 기본 제1단계와; 취득된 전기적인 데이터를 물리 신호로 변환한 후 기본 데이터 산정하고 결과를 도시하는 "시스템 실시간 작동 상태 감시" 기능의 제2단계와; 기본 순간치 데이터를 근거로 "시스템의 열성능 평가 변수 값 산정과 결과"를 도시하는 제3단계와; 2단계에서의 기본 데이터와 3단계에서의 열성능 평가 변수 값을 후처리용 데이터 파일로 저장하는 제4단계와; 현장에 설치된 지열원식 히트펌프 시스템의 상태를 TCP/IP 프로토콜을 활용하여 원격지(본사)에서 IP 접속을 통하여 원거리 원격 작동상태 감시 기능 및 제어를 수행하는 제5단계를 수행하게 된다.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.3
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• pp.51-57
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• 2012

Pacman is known as the terminator of the loved classic game in the world. In this paper, classic pacman game without using a keyboard or a mouse we should be able to play the game with simple hand gestures. In other words, It use motion game to be a substitute for the hand direction key using the center coordinates. Also, movements of the monster is to be replaced depending on your hand movements by extracting a pointer of hand taking pictures in the MFC dialog using Cam. In this paper, YCbCbr image is convert to RGB images to extract skin color, and multiplication operations and hybrid median filtering was used in order to obtain better images. And it is used to obtain movement of the hand area based on obtain the center of gravity of the hand region.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.229-232
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• 2011

최근 스마트 디바이스 기반의 다양한 콘텐츠 제작 공급에 대한 새로운 마켓 시장 형성과 태블릿 디바이스 기반의 전자책 시장 규모의 확대에 따른 새로운 유형의 디지털 콘텐츠 시장이 형성되고 있다. 디지털 미디어는 정보환경 범위를 종이의 범위에서 벗어나 매체와 연계한 다양한 형태로의 변화뿐만 아니라 서술 방식과 소통방식의 방법에도 변화를 발생하였다. 그리고 지면에서 국한된 아날로그 매체의 물리적, 공간적, 시간적인 한계를 뛰어넘어 다양한 콘텐츠를 손쉽게 접근할 수 있게 만들었다. 이런 환경에서 본문검색 서비스는 아날로그와 디지털 매체의 상호 공존관계를 형성할 수 있다. 본 논문에서는 그림종이문서를 본문검색이 가능한 이미지형태의 디지털문서로 변환해주는 디지털라이징 시스템으로 문자위치정보를 포함하는 광학문자인식(OCR)기능과 인식된 문자의 오류를 수정하는 에디터기능을 통해 추출된 내용을 XML형태로 제공하는 본문검색 시스템을 제안한다. 특히, 문자인식 후처리 공정에서 복수의 관학문자인식(OCR)엔진을 통해 결과 비교와 문자위치 정보 확인 및 편집, 맞춤법 검사 등의 특화된 기능 등은 본 논문에서 가지는 강점으로 디지털문서 구축에 소요되는 시간과 비용을 혁신적으로 절감시켜준다.