• 정보저장시스템학회:학술대회논문집
• /
• 정보저장시스템학회 2005년도 추계학술대회 논문집
• /
• pp.32-37
• /
• 2005

We developed a numerical simulator in order to study the Super-RENS/ROM (Super REsolution Near-Field Structure, Read Only Memory) using 3-dimensional FDTD (finite difference time domain) method. The simulation can be performed by three steps. In the first step, we utilized the vector-diffraction theory to calculate the characteristics of incident laser beam from the object-lens to the surface of the disk. At the second step, we fed the calculated result as an input for the main FDTD simulations on the optical layers in the disk structure. After performed the FDTD simulations, we took near-to-far field transformation for the reflected signal, from the surface of the disk to the detector. Finally, we can get reflected signal at the photo-diode. Using this developed simulator, we were able to study about the reading signal from various disk structures as a function of a laser beam position. We calculated reading signals for various pit sizes for Super-ROM structure, and it is found that the simple optical diffraction theory can not explain the reading mechanism of Super-ROM, and more complicated temperature dependent physics must be involved.

• 정보저장시스템학회논문집
• /
• 제2권2호
• /
• pp.138-143
• /
• 2006

We developed a numerical simulator in order to study the Super-RENS/ROM (Super REsolution Near-Field Structure, Read Only Memory) using 3-dimensional FDTD (finite difference time domain) method. The simulation can be performed by three steps. In the first step, we utilized the vector-diffraction theory to calculate the characteristics of incident laser beam from the object-lens to the surface of the disk. At the second step, we fed the calculated result as an input for the main FDTD simulations on the optical layers in the disk structure. After performed the FDTD simulations, we took near-to-far field transformation for the reflected signal, from the surface of the disk to the detector. Finally, we can get reflected signal at the photo-diode. Using this developed simulator, we were able to study about the reading signal from various disk structures as a function of a laser beam position. We calculated reading signals for various pit sizes for Super-ROM structure, and it is found that the simple optical diffraction theory can not explain the reading mechanism of Super-ROM, and more complicated temperature dependent physics must be involved.

• Journal of the Korean Data and Information Science Society
• /
• 제28권2호
• /
• pp.237-250
• /
• 2017

스포츠의 새로운 분야로 자리 잡고 있는 e-스포츠는 국내 뿐 아니라 해외에서도 많은 인기를 얻고 있다. 그 중 AOS (aeon of strife) 장르의 게임들은 대표적인 e-스포츠 대회 중 하나로 주목받으며, 방송 및 미디어 매체는 다양한 통계 지표를 활용한 게임 중계를 실시하고 있다. 본 논문에서는 AOS 장르의 게임인 리그오브레전드의 게임 데이터를 이용한 통계적 분석으로 게임 내 지표를 개선하고 승패예측을 위한 승패예측모형을 설계한다. 인자 분석을 통해 구한 인자로 기존의 지표를 개선하는 새로운 지표를 창출하고, 판별 분석, 인공신경망, SVM을 이용한 승패예측모형을 추정해 모형 간 비교를 실시하였다. 그 결과, 게임 내 포지션의 특성을 반영한 인자 점수로 새로운 지표를 제안하였으며, 세 가지 승패예측모형은 모두 평균 95% 의 높은 정분류율을 보였다.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
• /
• pp.41-46
• /
• 2006

This paper describes a marine watch system on a ship, which is aided by an image processing method. The system detects other ships through a navigational image sequence to prevent oversights, and it measures their bearings to maintain their movements. The proposed method is described, the detection techniques and measurement of bearings techniques are derived, and the results have been reported. The image is divided into small regions on the basis of the brightness value and then labeled. Each region is considered as a template. A template is assumed to be a ship. Then, the template is compared with frames in the original image after a selected time. A moving vector of the regions is calculated using an Excel table. Ships are detected using the characteristics of the moving vector. The video camera captures 30 frames per second. We segmented one frame into approximately 5000 regions; from these, approximately 100 regions are presumed to be ships and considered to be templates. Each template was compared with frames captured at 0.33 s or 0.66 s. In order to improve the accuracy, this interval was changed on the basis of the magnification of the video camera. Ships’ bearings also need to be determined. The proposed method can measure the ships’ bearings on the basis of three parameters: (1) the course of the own ship, (2) arrangement between the camera and hull, and (3) coordinates of the ships detected from the image. The course of the own ship can be obtained by using a gyrocompass. The camera axis is calibrated along a particular direction using a stable position on a bridge. The field of view of the video camera is measured from the size of a known structure on the hull in the image. Thus, ships’ bearings can be calculated using these parameters.

• Journal of Biosystems Engineering
• /
• 제33권6호
• /
• pp.416-422
• /
• 2008

This study was performed to design and construct a digital soil shear stress sensor in order to replace the conventional devices for measuring soil shear property. The developed digital shear stress measuring device can store measured data with GPS position information as a vector format into a computer. Based on the experiments at various field conditions, the measuring characteristic of the device was quite similar to that of a conventional device, SR-2 that has been a major tool to measure the soil shear property. It was concluded that the digital shear stress measuring device was an effective and comprehensive sensor for measuring soil shear property.

• 조명전기설비학회논문지
• /
• 제23권9호
• /
• pp.124-129
• /
• 2009

최근 자동차 및 자동화 등 많은 첨단 산업분야에서 산업용 모터 정밀 제어를 위한 인버터의 요구가 증가하고 있다. 본 논문에서는 FPGA를 이용하여 단일 제어 유닛으로 여러 개의 모터를 제어할 수 있는 SVPWM 모듈을 설계 제작하여 모터 정밀제어에 응용하고자 한다. 개발된 WVPWM 모듈에는 PWM 발생기뿐만 아니라 위치 및 전류센서 처리 부분과 데프타임 보상기 알고리즘도 함께 구현되었다. 개발 툴은 ALTERA Quartus 8.0을 사용하였으며 시뮬레이션에 의해 동작 특성을 검증하였고 실험을 통해 성능을 검증하였다.

• 한국조명전기설비학회지:조명전기설비
• /
• 제9권6호
• /
• pp.57-64
• /
• 1995

본 논문에서는 산업용 구동력으로써 대부분을 차지하는 유도전동기의 가변속 구동시 성능이 우수한 벡터제어 시스템에 관하여 연구하였다. 유도전동기의 회전자 각속도와 고정자 전류에 의한 간접적인 회전자 기준자속 추정방식을 채택하였으며, 이때의 전류제어기는 상호 간섭이 일어나지 않는 비간섭 동기 회전좌표계 PI제어기를 구성하였으며 시스템을 견실하게 하였다. 공간전압벡터 변조기법을 적용하여 전압 이용율의 향상과 전류제어가 용이하도록 하였다. 기기의 모델링 및 디지털 시뮬레이션을 통하여 속응성과 원활한 제어특성이 나타나는 유도전동기 구동시스템임을 입증하였다.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
• /
• pp.324-327
• /
• 2008

Microwave remote sensing has great potential, especially in monsoon Asia, since optical observations are often hampered by cloudy conditions. The radar backscattering characteristics of rice crop were investigated with a ground-based automatic scatterometer system. The system was installed inside a shelter in an experimental paddy field at the National Institute of Agricultural Science and Technology (NIAST) before transplanting. The rice cultivar was a kind of Japonica type, called Chuchung. The scatterometer system consists of X-band antennas, HP8720D vector network analyzer, RF cables, and a personal computer that controls frequency, polarization and data storage. This system automatically measures fully-polarimatric backscattering coefficients of rice crop every 10 minutes, accompanied by a digital camera that takes pictures in a fixed position with the same interval. The backscattering coefficients were calculated by applying a radar equation. Plant variables, such as leaf area index (LAI), biomass, plant height and weather conditions were measured periodically throughout the rice growth season. We have performed polarimetric decomposition of paddy data such as single, double and volume scattering to extract the scattering information effectively. We investigated the relationships between backscattering coefficients and the plant variables.

• Nuclear Engineering and Technology
• /
• 제54권1호
• /
• pp.193-206
• /
• 2022

Several algorithms for nuclear power plant (NPP) break event detection, isolation, localization, and size estimation are proposed. A break event can be promptly detected and isolated after its occurrence by simultaneously monitoring changes in the sensing readings and by employing an interquartile range-based isolation scheme. By considering the multi-sensor data block of a break to be rank-one, it can be located as the position whose lead field vector is most orthogonal to the noise subspace of that data block using the Multiple Signal Classification (MUSIC) algorithm. Owing to the flexibility of deep neural networks in selecting the best regression model for the available data, we can estimate the break size using multiple-sensor recordings of the break regardless of the sensor types. The efficacy of the proposed algorithms was evaluated using the data generated by Maanshan NPP simulator. The experimental results demonstrated that the MUSIC method could distinguish two near breaks. However, if the two breaks were close and of small sizes, the MUSIC method might wrongly locate them. The break sizes estimated by the proposed deep learning model were close to their actual values, but relative errors of more than 8% were seen while estimating small breaks' sizes.

• The Plant Pathology Journal
• /
• 제40권2호
• /
• pp.139-150
• /
• 2024

Huanglongbing (HLB) is a disease caused by the phloem-limited Candidatus Liberibacter asiaticus (CLas) that affects the citrus industry worldwide. To date, only indirect strategies have been implemented to eradicate HLB. Included among these is the population control of the psyllid vector (Diaphorina citri), which usually provides inconsistent results. Even though strategies for direct CLas suppression seem a priori more promising, only a handful of reports have been focused on a confrontation of the pathogen. Recent developments in polymer chemistry have allowed the design of polycationic self-assembled block copolymers with outstanding antibacterial capabilities. Here, we report the use of polymeric nano-sized bactericide particles (PNB) to control CLas directly in the phloem vasculature. The field experiments were performed in Rioverde, San Luis Potosí, and is one of the most important citrusproducing regions in Mexico. An average 52% reduction in the bacterial population was produced when PNB was injected directly into the trunk of 20 infected trees, although, in some cases, reduction levels reached 97%. These results position PNB as a novel and promising nanotechnological tool for citrus crop protection against CLas and other related pathogens.