• Title/Summary/Keyword: Single look error

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A Study on Look Error Estimation and Adaptive Array Angle Estimation (지향 오차 추정과 적응 배열 입사방향 추정 방법에 대한 연구)

  • Lee, Kwan-Hyeong;Song, Woo-Young;Lee, Myung-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.9
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    • pp.155-162
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    • 2011
  • It is using to incident angle estimation technique in order to target estimation in radar. This paper was estimated incident angle estimation for target using adaptive array incident angle and single look error incident angle estimation technique. We estimated signal incident angle of target to removal main lobe and side lobe to adaptive array incident angle technique. It is difficult to correctly target estimation because single look technique increase direction error of signal incident angle. In order to receive a desired target signal must be not almost look error between signal incident angle and look angle. we had decreased to occur a look error using delay time and single look condition to calculation a covariance when incident angle estimate. Through simulation, we show that the proposed incident angle estimation technique improves the performance of target estimation compared to previous method.

Development of Single-phase Fuzzy TPR for temperature control (온도제어를 위한 단상용 Fuzzy TPR 개발에 관한 연구)

  • Hong, Sung-Hun;Kang, Moon-Sung
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.1053-1055
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    • 1996
  • This paper proposes a Fuzzy TPR having the control function to a TPR used for the conversion of electricity in industrial field. The Fuzzy TPR based on the Fuzzy Logic Control technique is composed of the parts to calculate the low-level value and the high-level value. These values are calculated by error and change in error which are refer to the look-up table. To show the usefulness of the proposed Fuzzy TPR, it is applied to industrial temperature control system. In the results of experiment, we see that the system is able to fast reach steady-state, and for our approach to be robust to external disturbance than the method using the conventional TPR.

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Direct Digital Control of the Phase-Controlled Rectifier (위상제어정류기의 직접 디지털 제어)

  • 송의호;권봉환
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.40 no.1
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    • pp.31-38
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    • 1991
  • A direct digital control technique of a current source using the phase-controlled rectifier is presented. A digital firing technique without sensing the line voltage is proposed. This scheme generates firing pulses directly from error signal between command and output voltage. Thus the phase detection transformers filters and zero-crossing detector are unnecessary. The synchronism is modeled and analized. Also a software synchronization algorithm is presented without a look up table and controls the system in real time with fast dynamic characteristics. Using the single-chip microprocessor 8097BH, the direct digital control is implemented with minimal hardware structure. Using the time-weighted performance index, the optimal discrete IPM control technique is also proposed to control the current of the PCR.

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Nano Esto: An IDE for USN Application Developers (Nano Esto: USN 응용 소프트웨어 개발을 위한 통합개발환경)

  • Jung, Changhee;Woo, Duk-Kyun;Kim, Yongsang;Chun, Ingeol;Lim, Chaedeok
    • IEMEK Journal of Embedded Systems and Applications
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    • v.1 no.1
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    • pp.14-19
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    • 2006
  • Integrated development environment (IDE) plays an important role in reducing the developm ent time, thereby improving software development productivity. In recent years, ubiquitous sensor networks (USNs) have become increasingly popular. However their application software is developed mostly using command-line-based tools. Such a development process is not only likely to be error-prone but also inconvenient to debug errors. This paper describes a novel IDE for USN application developers called Nano Esto that provides a single, consistent, and integrated environment for building and executing USN applications. The Nano Esto helps the developers edit and cross-compile source code and download the executable image to the program memory of sensor nodes with just a few button clicks. It also provides support for configuring an application-specific kernel, simulating a wireless sensor network, and estimating power consumption in each sensor node. Currently, Nano Esto runs on Linux as well as on Windows with the same look and feel.

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Theoretical Prediction Method of Subcooled Flow Boiling CHF

  • Kwon, Yong-Min;Cahng, Soon-Heung
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05a
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    • pp.449-456
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    • 1998
  • A theoretical critical heat flux (CLE) model. based on lateral bubble coalescence on the heated wall, is proposed to predict the subcooled flow boiling CHF in a uniformly heated vertical tube. The model is based on the concept that a single layer of bubbles contacted to the heated wall events a bulk liquid from reaching the wall at near CHF condition. Comparisons between the model predictions and experimental data result in satisfactory agreement within less than 9.73 % root-mean-square error by the appropriate choice of the critical void fraction in the bubbly layer. The present model shows comparable performance with the CHF look-up table of Groeneveld et al.

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Feasibility Study on FSIM Index to Evaluate SAR Image Co-registration Accuracy (SAR 영상 정합 정확도 평가를 위한 FSIM 인자 활용 가능성)

  • Kim, Sang-Wan;Lee, Dongjun
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.847-859
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    • 2021
  • Recently, as the number of high-resolution satellite SAR images increases, the demand for precise matching of SAR imagesin change detection and image fusion is consistently increasing. RMSE (Root Mean Square Error) values using GCPs (Ground Control Points) selected by analysts have been widely used for quantitative evaluation of image registration results, while it is difficult to find an approach for automatically measuring the registration accuracy. In this study, a feasibility analysis was conducted on using the FSIM (Feature Similarity) index as a measure to evaluate the registration accuracy. TerraSAR-X (TSX) staring spotlight data collected from various incidence angles and orbit directions were used for the analysis. FSIM was almost independent on the spatial resolution of the SAR image. Using a single SAR image, the FSIM with respect to registration errors was analyzed, then use it to compare with the value estimated from TSX data with different imaging geometry. FSIM index slightly decreased due to the differencesin imaging geometry such as different look angles, different orbit tracks. As the result of analyzing the FSIM value by land cover type, the change in the FSIM index according to the co-registration error was most evident in the urban area. Therefore, the FSIM index calculated in the urban was mostsuitable for determining the accuracy of image registration. It islikely that the FSIM index has sufficient potential to be used as an index for the co-registration accuracy of SAR image.

Correlation among Ownership of Home Appliances Using Multivariate Probit Model (다변량 프로빗 모형을 이용한 가전제품 구매의 상관관계 분석)

  • Kim, Chang-Seob;Shin, Jung-Woo;Lee, Mi-Suk;Lee, Jong-Su
    • Journal of Global Scholars of Marketing Science
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    • v.19 no.2
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    • pp.17-26
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    • 2009
  • As the lifestyle of consumers changes and the need for various products increases, new products are being developed in the market. Each household owns various home appliances which are purchased through the choice of a decision maker. These appliances include not only large-sized products such as TV, refrigerator, and washing machine, but also small-sized products such as microwave oven and air cleaner. There exists latent correlation among possession of home appliances, even though they are purchased independently. The purpose of this research is to analyze the effect of demographic factors on the purchase and possession of each home appliances, and to derive some relationships among various appliances. To achieve this purpose, the present status on the possession of each home appliances are investigated through consumer survey data on the electric and energy product. And a multivariate probit(MVP) model is applied for the empirical analysis. From the estimation results, some appliances show a substitutive or complementary pattern as expected, while others which look apparently unrelated have correlation by co-incidence. This research has several advantages compared to previous literatures on home appliances. First, this research focuses on the various products which are purchased by each household, while previous researches such as Matsukawa and Ito(1998) and Yoon(2007) focus just on a particular product. Second, the methodology of this research can consider a choice process of each product and correlation among products simultaneously. Lastly, this research can analyze not only a substitutive or complementary relationship in the same category, but also the correlation among products in the different categories. As the data on the possession of home appliances in each household has a characteristic of multiple choice, not a single choice, a MVP model are used for the empirical analysis. A MVP model is derived from a random utility model, and has an advantage compared to a multinomial logit model in that correlation among error terms can be derive(Manchanda et al., 1999; Edwards and Allenby, 2003). It is assumed that the error term has a normal distribution with zero mean and variance-covariance matrix ${\Omega}$. Hence, the sign and value of correlation coefficients means the relationship between two alternatives(Manchanda et al., 1999). This research uses the data of 'TEMEP Household ICT/Energy Survey (THIES) 2008' which is conducted by Technology Management, Economics and Policy Program in Seoul National University. The empirical analysis of this research is accomplished in two steps. First, a MVP model with demographic variables is estimated to analyze the effect of the characteristics of household on the purchase of each home appliances. In this research, some variables such as education level, region, size of family, average income, type of house are considered. Second, a MVP model excluding demographic variables is estimated to analyze the correlation among each home appliances. According to the estimation results of variance-covariance matrix, each households tend to own some appliances such as washing machine-refrigerator-cleaner-microwave oven, and air conditioner-dish washer-washing machine and so on. On the other hand, several products such as analog braun tube TV-digital braun tube TV and desktop PC-portable PC show a substitutive pattern. Lastly, the correlation map of home appliances are derived using multi-dimensional scaling(MDS) method based on the result of variance-covariance matrix. This research can provide significant implications for the firm's marketing strategies such as bundling, pricing, display and so on. In addition, this research can provide significant information for the development of convergence products and related technologies. A convergence product can decrease its market uncertainty, if two products which consumers tend to purchase together are integrated into it. The results of this research are more meaningful because it is based on the possession status of each household through the survey data.

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