• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.693-695
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• 2014

Radioactive isotopes for radiation diagnosis is production by using Cyclotron like a PET. Radioactive isotopes is influenced product yield according to shape and size of the proton beam and target irradiation position by cyclotron. And to develop a device for measuring the distribution of the beam to increase the loss of the beam. Beam measuring device is measured vertically beam current according move the two wires. In this way, by using the beam current value in each position you are able to know the cross section and location information of the beam. By scanning cross-section for X-axis Y-axis of beam acquires data of beam. Print this into 2D graph, and analyze the result. You can save this result by documentation process.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1207-1212
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• 2018

The signal intelligence (SIGINT) technology is actively used for collecting various data, in a number of fields, including a military industry. In order to collect the signal information and data and to transmit/receive the collected data efficiently, the accurate angle-of-arrival (AOA) information is required and communication disturbance from the interference or jamming signal should be minimized. In this paper, we present the structure of an adaptive beam-forming satellite system based on the planar array antenna, for collecting and transmitting/receiving the signal information and data efficiently. The presented adaptive beam-forming system consists of an antenna in the form of a planar array, an AOA estimator based on the Multiple Signal Classification (MUSIC) algorithm, an adaptive Minimum Variance Distortionless Response (MVDR) interference canceler, a signal processing and D/B unit, and a transmission beamformer based on Minimum mean Square Error (MMSE). In addition, through the computer simulation, we evaluate and analyze the performance of the proposed system.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.519-522
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• 2004

수중 음향 탐지 시스템에서 빔 형성 기법은 탐지 성능에 큰 영향을 미치기 때문에 최적의 빔 설계는 오랫동안 많은 연구자들에 의해 연구되어 왔다. 실제로 최적의 빔 형성기를 구현할 때에는 각각의 센서에 대한 특성 고려와 파워를 효율적으로 전달하기 위한 정합회로의 설계가 필수적이다. 이전의 논문에서는 BeamCAD Tool을 이용한 최적 가중치의 계산, 센서 임피던스 측정 데이터와 Sensor Modeling Tool을 이용한 등가회로 모델링 그리고 Impedance Matching Tool을 이용한 정합회로 설계 기법에 대해서 소개하였다. 본 논문에서는 이러한 기법들과 함께 ABCD 전송 파라메터를 이용한 센서 가중치 보정 기법을 소개한다. 그리고 이러한 여러 기법들을 이용하여 최적빔 설계를 위한 가중회로를 구성하는 방법에 대해서 논의한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9A
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• pp.889-895
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• 2010

In this paper, we have studied the implementation and adaptation of a smart antenna system for mobile terminals. We have designed a smart antenna system with switching beam structure in order to reduce the hardware and computational complexity. Additionally we have analyzed the reduction of the effect of multipath fading due to beamforming using real measurement data from commercial CDMA cellular channel environments. After analyzing the measurement data, we found out that the effect of fading reduces by ~3dB due to the effect of $2{\times}2$ beamforming in mobile terminals with 6dB beamforming gain.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.455-458
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• 2004

소나 시스템의 표적 탐지 성능을 향상시키기 위해 물리적으로 제한된 길이의 어레이를 확장하는 합성 어퍼쳐 소나에 대한 연구와 실험이 이루어지고 있다. 본 논문에서는 왜곡된 어레이의 형상을 추정하여 왜곡을 보상한 후에 빔 영역에서 어레이를 합성하는 FFTSA(Fast Fourier Transform Synthetic Aperture) 기법의 성능을 분석하였다. 실험 데이터로는 한국 근해에서 견인 어레이로부터 획득한 데이터를 이용하였으며 실측된 데이터로 부어레이 간의 시-공간적인 위상 차이를 보상함으로써 어레이 길이를 확장하였다.

• Journal of Internet Computing and Services
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• v.23 no.3
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• pp.13-20
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• 2022

IEEE 802.11ay Wi-Fi is the next generation wireless technology and operates in mmWave band. It supports the MU-MIMO (Multiple User Multiple Input Multiple Output) transmission in which an AP (Access Point) can transmit multiple data streams simultaneously to multiple STAs (Stations). To this end, the AP should perform MU-MIMO beamforming training with the STAs. For efficient MU-MIMO beamforming training, it is important for the AP to estimate signal strength measured at each STA at which multiple beams are used simultaneously. Therefore, in the paper, we propose a deep learning-based link quality estimation scheme. Our proposed scheme estimates the signal strength with high accuracy by utilizing a deep learning model pre-trained for a certain indoor or outdoor propagation scenario. Specifically, to estimate the signal strength of the multiple concurrent beams, our scheme uses the signal strengths of the respective single beams, which can be obtained without additional signaling overhead, as the input of the deep learning model. For performance evaluation, we utilized a Q-D (Quasi-Deterministic) Channel Realization open source software and extensive channel measurement campaigns were conducted with NIST (National Institute of Standards and Technology) to implement the millimeter wave (mmWave) channel. Our simulation results demonstrate that our proposed scheme outperforms comparison schemes in terms of the accuracy of the signal strength estimation.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.3-8
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• 2014

We consider a limited feedback based hybrid beamforming which reduces the energy of feedback information. In the millimeter wave channel, some rays with large ray gain dominate energy of the channel. Using this point, we propose a channel feedback scheme that employs limited number of channel rays. Also, we provide a hybrid beamforming scheme for the limited feedback system. Based on the simulation results, the proposed scheme shows a comparable data rate performance with conventional schemes, while it remarkably reduces energy of channel feedback.

• Journal of the Korean Society for Railway
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• v.15 no.3
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• pp.231-236
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• 2012

In this paper, aerodynamic noise characteristics of high-speed trains were deduced from the beamforming method. First, pass-by noise of high-speed trains was measured by a microphone array system. This measurement suggested that the majority of the aerodynamic noise produced came from the bogie area, the pantograph and its cover, and inter-coach gaps. Then, beampower outputs of a position in high-speed trains were obtained from the beamforming method. By Fourier transform, sound characteristics of the position in the frequency domain were deduced from the beamforming power spectrum. From this study, aerodynamic noise characteristics from the major sources of high-speed trains were drawn.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1110-1116
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• 2021

In this paper, we propose a conformal Ku-band data link antenna to ensure low RCS of stealth UAV. As a phased array antenna with electrical beam steering function, a transmitter and a receiver were designed and manufactured for FDD communication, respectively. Each antenna is designed as a 12*12 planar array antenna and has a function to form a uni-directional pattern and a bi-directional pattern through phase control of unit elements. The beam steering range is designed to be able to steer up to 60 degrees in theta direction and 360 degrees in the phi direction. As a result of manufacturing and measurement, the conformal type radome has low transmission loss and meets the required specifications including system performance. The feasibility of mounting the stealth UAV has been confirmed, and future research directions such as interworking of baseband devices and conversion to digital beam steering function are suggested.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.3
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• pp.459-464
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• 2001

We propose a transmit beamforming algerian for array antenna in FDD (Frequency Division Duplex) environments. The proposed method estimates the directions and spectra of the users, and constructs the spatial covariance matrix of the interferences at the downlink frequency. The weights are computed by that covariance matrix and desired user's direction vector Simulations are performed under Rayleigh fading environments. The proposed method don't need the data feedback, has the enhanced performance in BER (Bit Error Rate).