• International journal of advanced smart convergence
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• 제7권1호
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• pp.1-6
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• 2018

In addition to the instability of energy import costs caused by the depletion of petroleum resources, which is a representative energy resource, and the strengthening of various regulations such as the convention on climate change, the plant for bio energy production, which is being watched as the next generation energy, and became subject of various complaints. In order to solve this problem, the bio-plant is underground and the ground is parked, making the convenience and accessibility of citizens more and more accessible. In this situation, the development of bioenergy production technology also increases the risk factor in bioenergy production process. Accordingly this paper explains method about apply the wide angle camera based AOA algorithm to the bio plant to prevent the accidents from spreading due to the lack of facilities and safety devices and the aging of the facilities and suggests a technique that can quickly identify the location and direction when it occurs.

• 한국음향학회지
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• 제16권1호
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• pp.60-66
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• 1997

신호도착방향 추정에 관한 대부분의 연구는 신호원을 점신호원이라 두고 이루어져 왔으나, 실제 환경에서는 신호원을 퍼진 신호모형으로 두면 더 알맞게 추정할 수 있을 때가 많다. 신호원이 어떤 영역에 걸쳐 퍼져 있을 때 우리는 잘 알려진 신호도착방향 추정 방법들을 직접 사용할 수 없다. 이 논문에서는 2차원 퍼진 신호원을 중심각과 퍼짐의 정도로 나타내고, 3차원 공간에서 두단계 기법을 써서 모수형 퍼진 신호원의 수직, 수평각을 추정하였다.

• ETRI Journal
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• 제42권3호
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• pp.311-323
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• 2020

Encrypted traffic classification plays a vital role in cybersecurity as network traffic encryption becomes prevalent. First, we briefly introduce three traffic encryption mechanisms: IPsec, SSL/TLS, and SRTP. After evaluating the performances of support vector machine, random forest, naïve Bayes, and logistic regression for traffic classification, we propose the combined approach of entropy estimation and artificial neural networks. First, network traffic is classified as encrypted or plaintext with entropy estimation. Encrypted traffic is then further classified using neural networks. We propose using traffic packet's sizes, packet's inter-arrival time, and direction as the neural network's input. Our combined approach was evaluated with the dataset obtained from the Canadian Institute for Cybersecurity. Results show an improved precision (from 1 to 7 percentage points), and some application classification metrics improved nearly by 30 percentage points.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.219-223
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• 2003

This paper describes an estimation of DOA(Direction Of Arrival) measurement system using DBF receiver with linear array antenna. This DBF receiver is composed of resistive FET mixer using low IF mettled. A radio frequency(RF), a local oscillator(LO) and ail intermediate frequency(IF) considered in this research are 2.09 GHz, 2.08 GHz and 10 MHz, respectively. This receiver is composed of a band-pass filter, a low-pass filter, a DC bias circuit. DOA measurement system is consist of linear array antenna, DBF receiver, AD control box and computer in the anechoic chamber. Receiving antenna is 4-array monopole antenna and DBF receiver is 4-Ch resistive FET mixer without amplifier. DOA algorithm is implemented using MUSIC algorithm with high resolution. We show that the results of DOA is $-30^{\circ},\;0^{\circ}$ and $60^{\circ}$, respectively. And we know that DOA estimation error occur by antenna radiation pattern and fabrication error of antenna array.

• International journal of advanced smart convergence
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• 제11권3호
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• pp.102-118
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• 2022

With the development of digital content software production technology and the technological progress of related hardware, the social status quo in the post-epidemic era, the popularization and application of 5G networks, the market and consumers' increasing demand for digital content products, artificial intelligence, virtual digital human, virtual Idols, virtual live, self-media content and metaverse-related content industries are all developing rapidly. Virtual idols, virtual digital human, etc. are not only accelerating innovation in production technology. The economic cost, technical difficulty and time requirements of production are also greatly reduced. With the arrival and development of the Metaverse, the author believes that the content industry with virtual digital humans as the core will continue to develop in the direction of refinement, specialization, facilitation and customization. In this article, we will analyze and study the production of virtual digital human based on Photoscan technology and Unreal Engine 5 Metahuman software, and discuss the application status and future development of related content.

• 한국컴퓨터산업교육학회:학술대회논문집
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• 한국컴퓨터산업교육학회 2003년도 제4회 종합학술대회 논문집
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• pp.105-110
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• 2003

Number of information users of industry, school and research institute with arrival of knowledge information society are in trend that increase gradually the 21th century. Manufacture user number of database been circulating is examined to fourteen million, six hundred and twenty-four thousand people in internal until end of 2002 if follow to Korea data base promotion center, this shows increase more than yearly mean $70\%$ every year by increasing provision $70.3\%$ past years. That collect rapidly and analyze connection importance information of scientific technique field in this hard fact and offer efficiently timely to investigator processing can say as indispensable indispensability a element in country science technique elevation. Wish to illuminate Specialized Information Center of scientific technique field's role and significance in this hard fact in this research, and examine the role and significance. Together, wish to present way for research direction and Specialized Information Center development by introducing phase thesis and synthetic middle, effort of Korea Institute of Science and Technology Information(KISTI) for special skill development way preparation and study finding for each Specialized Information Center.

• 제어로봇시스템학회논문지
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• 제17권3호
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• pp.211-217
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• 2011

This paper proposes a quasi-optimal linear DOA (Direction-of-Arrival) estimator which is necessary for the development of a real-time robot auditory system tracking moving acoustic source. It is well known that the use of conventional nonlinear filtering schemes may result in the severe performance degradation of DOA estimation and not be preferable for real-time implementation. These are mainly due to the inherent nonlinearity of the acoustic signal model used for DOA estimation. This motivates us to consider a new uncertain linear acoustic signal model based on the linear prediction relation of a noisy sinusoid. Using the suggested measurement model, it is shown that the resultant DOA estimation problem is cast into the NCRKF (Non-Conservative Robust Kalman Filtering) problem [12]. NCRKF-based DOA estimator provides reliable DOA estimates of a fast moving acoustic source in spite of using the noise-corrupted measurement matrix in the filter recursion and, as well, it is suitable for real-time implementation because of its linear recursive filter structure. The computational efficiency and DOA estimation performance of the proposed method are evaluated through the computer simulations.

• 한국음향학회지
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• 제30권3호
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• pp.129-135
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• 2011

An algorithm is presented for estimating the 3-D location (i.e., azimuth angle, elevation angle, and range) of multiple sources with a uniform circular array (UCA) consisting of an even number of sensors. Recently the rank reduction (RARE) algorithm for partly-calibrated sensor arrays was developed. This algorithm is applicable to sensor arrays consisting of several identically oriented and calibrated linear subarrays. Assuming that a UCA consists of M sensors, it can be divided into M/2 identical linear subarrays composed of two facing sensors. Based on the structure of the subarrays, the steering vectors are decomposed into two parts: range-independent 2-D direction-of-arrival (DOA) parameters, and range-relevant 3-D location parameters. Using this property we can estimate range-independent 2-D DOAs by using the RARE algorithm. Once the 2-D DOAs are available, range estimation can be obtained for each source by defining the 1-D MUSIC spectrum. Despite its low computational complexity, the proposed algorithm can provide an estimation performance almost comparable to that of the 3-D MUSIC benchmark estimator.

• 디지털산업정보학회논문지
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• 제15권1호
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• pp.67-76
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• 2019

Despite attractive advantages such as good time-frequency localization and improved spectral efficiency, filter bank multicarrier with offset quadrature amplitude modulation (FBMC/OQAM) suffers from multipath fading. In highly frequency-selective channels, the effect of multipath interference can significantly distort the FBMC/OQAM signal due to the absence of cyclic prefix. To resolve the problem of the multipath interference in FBMC/OQAM, this paper proposes applying an antenna array that provides well shaped beam pattern for each multipath. To evaluate the performance of the proposed array system, various computer simulations have been conducted. The accuracy of direction of arrival estimation is demonstrated through spatial spectrum for a different number of antennas in a sub-array. The performance improvement is presented in terms of bit error rate. We found that the proposed array system mitigate the multipath interferences in Extended Typical Urban model with 12 antennas in a sub-array. Moreover, as the number of antennas in a sub-array increases, the system provides a signal-to-noise ratio gain.

• ETRI Journal
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• 제43권5호
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• pp.941-949
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• 2021

In this study, a spatial spectrum method is proposed to cope with the pilot spoofing attack (PSA) problem by exploiting the of uplink-downlink channel reciprocity in time-division-duplex multiple-input multiple-output systems. First, the spoofing attack in the uplink stage is detected by a threshold derived from the predefined false alarm based on the estimated spatial spectrum. When the PSA occurs, the transmitter (That is Alice) can detect either one or two spatial spectrum peaks. Then, the legitimate user (That is Bob) and Eve are recognized in the downlink stage via the channel reciprocity property based on the difference between the spatial spectra if PSA occurs. This way, the presence of Eve and the direction of arrival of Eve and Bob can be identified at the transmitter end. Because noise is suppressed by a spatial spectrum, the detection performance is reliable even for low signal-noise ratios and a short training length. Consequently, Bob can use beamforming to transmit secure information during the data transmission stage. Theoretical analysis and numerical simulations are performed to evaluate the performance of the proposed scheme compared with conventional methods.