• 제목/요약/키워드: Radar Variables

검색결과 65건 처리시간 0.02초

퍼지 추정기에의한 동적 시스템의 상태 추정에 관한 연구 (A Study on the State Estimaion of Dynamic system using Fuzzy Estimator)

  • 문주영;박승현;이상배
    • 한국지능시스템학회:학술대회논문집
    • /
    • 한국퍼지및지능시스템학회 1997년도 추계학술대회 학술발표 논문집
    • /
    • pp.350-355
    • /
    • 1997
  • The problem of mathematical model for an unknown system by measureing its input-output data pairs is generally referred to as state estimates. The state estimation problem is often of importance in its own right since we may want to know the value of the states. For instance, in navigation, we may take noisy positional fixes using satelite or radar navigation, and the estimator can use these measurements to provide accurate estimates of current position, hedaing, and velocity. And the state estimates can also be used for control purposes. Then it is very important to know the state of plant. In this paper, the theory of the minimization of a loss function was used to design the fuzzy system. Here, the used teory is Least Square Esimation method. This parametrization has the Linear in the parameters charcteristic that allows standard parameter estimation technique to be used to estimate the parameters of the fuzzy system. The combination of the fuzzy system and the estimation m thod then performs as a nonlinear estimator. If several fuzzy label are defined for the input variables at the antecedent part, the fuzzy system then behaves as a collection of nonlinear estimators where different regions of rules have different parameters. In simulation results, the fuzzy model controlled a difference in the structure between the actual plant and the fuzzy estimator. It is also proved that the fuzzy system is equivalent to its transformed system. therefore we was able to get the state space equation of system with the estimated paramater.

  • PDF

통합된 상용 툴을 이용한 전투기급 항공기 개념설계 (Conceptual Design of Fighter-class Aircraft Using Integrated Commercial Tools)

  • 이성진;남화진;박영근;오장환;이대열
    • 한국군사과학기술학회지
    • /
    • 제17권2호
    • /
    • pp.189-196
    • /
    • 2014
  • Automated design program using commercial process integration and optimization program was developed for conceptual design of fighter-class aircraft. Wind tunnel test data and performance analysis results were compared for the verification of analysis tool of this program, and the usefulness of the tool was found. After integration with radar cross section analysis tool, the correlation with configuration design variables of wing, tail and performance parameters was identified by design of experiment, and the optimized configuration for weight and RCS was derived from optimization of empty weight and average frontal RCS value. After parameter definition of fuselage, the program can be implemented for full aircraft configuration.

다른 원격탐사 센서로 추출한 강우자료의 이질성과 이에 의한 비선형유출반응에 미치는 영향 (Investigating Remotely Sensed Precipitation from Different Sources and Their Nonlinear Responses in a Physically Based Hydrologic Model)

  • 오남선;이길하;김상준
    • 한국수자원학회논문집
    • /
    • 제39권10호
    • /
    • pp.823-832
    • /
    • 2006
  • 강우는 물과 에너지 순환에서 가장 중요한 역할을 한다. 이 연구에서는 두개의 다른 원격탐사 센서를 이용하여 추출한 강우자료의 불확실성 (uncertainty)에 대하여 검토해 보았으며, 이에 의한 오차가 비선형 수치수문모형에서 수문인자(유출)를 모의할 때 어떻게 영향을 미치는가를 살펴보았다. 지상에서 관측된 강우 관측을 이용하여 WSR-88D (NEXRAD)에 의해 추출한 레이더 강우, 그리고 IR (Infrared) 밴드를 기반으로 하는 인공위성 강우관측을 비교 검토하였으며, 세 가지의 서로 다른 강우와 현장에서 측정된 기상자료를 입력 자료로 사용하여, 오프라인 CLM (Community Land Model) 수문모형으로 유출량을 모의하였다. 이 연구에서 물리적 이론을 기반으로 하는 CLM수문 모형의 매개변수는 지표면-대기의 수문반응 (land-atmosphere interaction)을 적절하게 묘사하도록 정의되었다고 가정한다. 다른 원격탐사 센서를 이용하여 추출한 강우자료는 시공간적으로 다른 양상을 보여 주며, 수치모형의 실험 결과는 강우입력의 불확실성이 수문반응의 결과에 어떻게 영향을 미치는지를 보여준다. 이 연구는 앞으로 우리나라에서 개발 및 활용가능성이 있는 레이더 강우와 인공위성 강우에 대한 사전 지식을 제공하고, 동시에 수치 수문모형을 수행할 때 수문반응의 불확실성에 대한 정보를 제공해 주며, 결국은 기후 변화에 따른 수자원의 재분배를 이해하는데 이바지할 것이다.

지표변위를 고려한 북극 동토 지역의 자원개발 플랜트 건설 최적 입지 분석: 캐나다 Athabasca 지역의 오일샌드 플랜트 사례 연구 (Analysis of Optimal Locations for Resource-Development Plants in the Arctic Permafrost Considering Surface Displacement: A Case Study of Oil Sands Plants in the Athabasca Region, Canada)

  • 김태욱;김영석;김세원;한향선
    • 지질공학
    • /
    • 제33권2호
    • /
    • pp.275-291
    • /
    • 2023
  • 지구온난화로 인해 극지방에 대한 접근성이 높아짐에 따라 석유자원이 풍부한 영구동토 지역에서 자원개발 플랜트 건설의 수요가 증가하고 있다. 동토 지역에서의 자원개발 플랜트 건설 입지는 동토 활성층의 융해와 동결에 기인하는 지표변위가 필수적으로 고려되어야 한다. 그러나 동토의 변위를 고려하여 자원개발 플랜트 건설의 입지를 선정한 연구 사례는 거의 없다. 이 연구에서는 캐나다 앨버타 주의 Athabasca 남부 지역에서 최적의 오일샌드 개발 플랜트 건설 입지를 선정하기 위해 지표변위를 비롯한 다양한 공간정보를 활용하여 계층화 분석(Analytical Hierarchy Process)을 수행하였고, 동토 지역에서의 자원개발 플랜트 건설 활동에 있어 지표변위의 중요성을 논의하였다. 2007년 2월부터 2011년 3월까지 획득된 시계열 ALOS PALSAR 영상에 Small BAseline Subset-Interferometric Synthetic Aperture Radar 기법을 적용하여 지표변위 속도 정보를 구축하였고, ERA5 재분석 자료로부터 2000~2010년 기간에 대한 평균 기온, 지표온도, 지중온도 정보를 구축하였다. 도로 및 철도와 토지피복 공간정보는 각각 캐나다 연방 통계청과 북미환경협력위원회에서 제공하는 자료를 구축하여 활용하였다. 토지피복, 지표변위, 도로 접근성을 가장 중요한 공간정보로 설정하여 수행한 최적 입지 분석 결과는 2010년 이후 건설된 오일샌드 플랜트 건설지와 비교하여 그 타당성이 확인되었고, 입지 적합도 평가에 대한 지표변위의 민감도는 매우 높은 것으로 분석되었다. 이 연구를 통하여 동토 지역에서 최적의 자원개발 플랜트 건설지를 선정하는데 지표변위가 필수적으로 고려되어야 함이 확인되었다.

Optimization of the Gain Parameters in a Tracking Module for ARPA system on Board High Dynamic Warships

  • Pan, Bao-Feng;Njonjo, Anne Wanjiru;Jeong, Tae-Gweon
    • 한국항해항만학회지
    • /
    • 제40권5호
    • /
    • pp.241-247
    • /
    • 2016
  • The tracking filter plays a key role in the accurate estimation and prediction of maneuvering a vessel's position and velocity when attempting to enhance safety by avoiding collision. Therefore, in order to achieve accurate estimation and prediction, many oceangoing vessels are equipped with the Automatic Radar Plotting Aid (ARPA) system. However, the accuracy of prediction depends on the tracking filter's ability to reduce noise and maintain a stable transient response. The purpose of this paper is to derive the optimal values of the gain parameters used in tracking a High Dynamic Warship. The algorithm employs a ${\alpha}-{\beta}-{\gamma}$ filter to provide accurate estimates and updates of the state variables, that is, positions, velocity and acceleration of the high dynamic warship based on previously observed values. In this study, the filtering coefficients ${\alpha}$, ${\beta}$ and ${\gamma}$ are determined from set values of the damping parameter, ${\xi}$. Optimization of the damping parameter, ${\xi}$, is achieved experimentally by plotting the residual error against different values of the damping parameter to determine the least value of the damping parameter that results in the optimum smoothing coefficients leading to a reduction in the noise corruption effect. Further investigation of the performance of the filter indicates that optimal smoothing coefficients depend on the initial and average velocity of the target.

A Similarity Weight-based Method to Detect Damage Induced by a Tsunami

  • Jeon, Hyeong-Joo;Kim, Yong-Hyun;Kim, Yong-Il
    • 한국측량학회지
    • /
    • 제34권4호
    • /
    • pp.391-402
    • /
    • 2016
  • Among the various remote sensing sensors compared to the electro-optical sensors, SAR (Synthetic Aperture Radar) is very suitable for assessing damaged areas induced by disaster events owing to its all-weather day and night acquisition capability and sensitivity to geometric variables. The conventional CD (Change Detection) method that uses two-date data is typically used for mapping damage over extensive areas in a short time, but because data from only two dates are used, the information used in the conventional CD is limited. In this paper, we propose a novel CD method that is extended to use data consisting of two pre-disaster SAR data and one post-disaster SAR data. The proposed CD method detects changes by using a similarity weight image derived from the neighborhood information of a pixel in the data from the three dates. We conducted an experiment using three single polarization ALOS PALSAR (Advanced Land Observing Satellite/Phased Array Type L-Band) data collected over Miyagi, Japan which was seriously damaged by the 2011 east Japan tsunami. The results demonstrated that the mapping accuracy for damaged areas can be improved by about 26% with an increase of the g-mean compared to the conventional CD method. These improved results prove the performance of our proposed CD method and show that the proposed CD method is more suitable than the conventional CD method for detecting damaged areas induced by disaster.

안전한 항공기 운항을 위한 현업 전지구예보모델 기반 깊은 대류 예측 지수: Part 1. 개발 및 통계적 검증 (Aviation Convective Index for Deep Convective Area using the Global Unified Model of the Korean Meteorological Administration, Korea: Part 1. Development and Statistical Evaluation)

  • 박이준;김정훈
    • 대기
    • /
    • 제33권5호
    • /
    • pp.519-530
    • /
    • 2023
  • Deep convection can make adverse effects on safe and efficient aviation operations by causing various weather hazards such as convectively-induced turbulence, icing, lightning, and downburst. To prevent such damage, it is necessary to accurately predict spatiotemporal distribution of deep convective area near the airport and airspace. This study developed a new index, the Aviation Convective Index (ACI), for deep convection, using the operational global Unified Model of the Korea Meteorological Administration. The ACI was computed from combination of three different variables: 3-hour maximum of Convective Available Potential Energy, averaged Outgoing Longwave Radiation, and accumulative precipitation using the fuzzy logic algorithm. In this algorithm, the individual membership function was newly developed following the cumulative distribution function for each variable in Korean Peninsula. This index was validated and optimized by using the 1-yr period of radar mosaic data. According to the Receiver Operating Characteristics curve (AUC) and True Skill Score (TSS), the yearly optimized ACI (ACIYrOpt) based on the optimal weighting coefficients for 1-yr period shows a better skill than the no optimized one (ACINoOpt) with the uniform weights. In all forecast time from 6-hour to 48-hour, the AUC and TSS value of ACIYrOpt were higher than those of ACINoOpt, showing the improvement of averaged value of AUC and TSS by 1.67% and 4.20%, respectively.

Numerical Model Test of Spilled Oil Transport Near the Korean Coasts Using Various Input Parametric Models

  • Hai Van Dang;Suchan Joo;Junhyeok Lim;Jinhwan Hur;Sungwon Shin
    • 한국해양공학회지
    • /
    • 제38권2호
    • /
    • pp.64-73
    • /
    • 2024
  • Oil spills pose significant threats to marine ecosystems, human health, socioeconomic aspects, and coastal communities. Accurate real-time predictions of oil slick transport along coastlines are paramount for quick preparedness and response efforts. This study used an open-source OpenOil numerical model to simulate the fate and trajectories of oil slicks released during the 2007 Hebei Spirit accident along the Korean coasts. Six combinations of input parameters, derived from a five-day met-ocean dataset incorporating various hydrodynamic, meteorological, and wave models, were investigated to determine the input variables that lead to the most reasonable results. The predictive performance of each combination was evaluated quantitatively by comparing the dimensions and matching rates between the simulated and observed oil slicks extracted from synthetic aperture radar (SAR) data on the ocean surface. The results show that the combination incorporating the Hybrid Coordinate Ocean Model (HYCOM) for hydrodynamic parameters exhibited more substantial agreement with the observed spill areas than Copernicus Marine Environment Monitoring Service (CMEMS), yielding up to 88% and 53% similarity, respectively, during a more than four-day oil transportation near Taean coasts. This study underscores the importance of integrating high-resolution met-ocean models into oil spill modeling efforts to enhance the predictive accuracy regarding oil spill dynamics and weathering processes.

열대강우관측(TRMM) 위성의 TMI와 PR에서 관측된 열대해양에서의 강우 특성 (Rainfall Characteristics in the Tropical Oceans: Observations using TRMM TMI and PR)

  • 서은경
    • 한국지구과학회지
    • /
    • 제33권2호
    • /
    • pp.113-125
    • /
    • 2012
  • 열대강우관측(TRMM) 위성에 탑재된 두 독립적인 기기인 마이크로파 센서(TMI)와 강수레이더(PR)를 통해 추정된 지표에서의 강우강도와 강수 관련 변수들을 네 개의 주요 열대해양에서 비교하였다. 해수면의 온도가 가장 높은 서태평양에서 가장 많은 강수구름이 발생하며, 이는 동태평양과 대서양 보다 1.5배 많은 빈도수이다. 반면 대류형과 혼합형에서 동태평양이 가장 강한 강우강도를 나타냈으며, 전체 강수 화소에 대해서는 대서양이 가장 강한 강우강도를 보였다. 한편 PR의 강우강도를 참값으로 볼 때 TMI의 강우강도의 편향은 강수유형과 지역에 따라 그 크기가 매우 다르게 나타났다. 더욱이 강수유형별 편향은 서로 다른 부호를 보였다. 특히 이 연구에서 선정한 열대해양들은 비교적 유사한 지구물리적 환경을 가지고 있지만, 그 편향의 크기가 지역에 따라 2배 이상의 차이가 일어났다. 따라서 마이크로파로부터 추정된 강수량에 대한 검증은 강수유형별 및 지역적으로 수행되어야 하며, 또한 국지적 강수 특성을 고려한 보다 정교한 TMI 알고리즘의 개발 및 개선이 필요함을 의미한다.

호텔기업 종업원의 감성지능이 고객지향성과 CRM성과에 미치는 영향 (The Effects of Emotional Intelligence on the Customer Orientation and Customer Relationship Management Performance of Hotel Employees)

  • 전타식;남택영
    • 유통과학연구
    • /
    • 제10권10호
    • /
    • pp.17-24
    • /
    • 2012
  • Purpose - This study aimed to (a) investigate the effects of emotional intelligence on customer orientation, (b) examine the impact of customer orientation on customer relationship management (CRM) performance (including CRM-related variables such as 'relationship commitment,' 'image of corporation,' and 'customer loyalty'), and (c) identify the conceptual framework of emotional intelligence. Research design, data, and methodology - The data were collected using a questionnaire given to a sample of employees of luxury hotels in the metropolitan area. To test the hypotheses, AMOS were conducted for the 271 respondents of the sample using the SPSS Win 17.0 software. The concept of emotional intelligence (EI) has been on the radar of many leaders and managers over the past few decades. Emotional intelligence is generally accepted to be a combination of emotional and interpersonal competencies that influence behavior, thoughts, and interactions with others. Emotional intelligence consists of four factors: understanding the self's emotion, understanding other people's emotions, emotion utilization, and emotion control. Understanding the self's emotion means to understand of my own emotions. Understanding other people's emotions is to understand of the emotions of the people around me and to know how my friends feel based on their behavior. The concept of emotion utilization means to set goals for myself and then try to achieve them, encouraging myself to do my best. The concept of emotion control means I can control my temper, handle difficult situations rationally, and calm down quickly when I am very angry. Results - As a result of the analysis, three factors (understanding the self's emotion, understanding of other people's emotions, and emotion utilization) were shown to have a significant effect on customer orientation. Emotion control had an insignificant effect on customer orientation. Only emotion control makes it difficult to solve customers' problems because it is a passive behavior. In order to solve the customers' problems, hotel employees have to show a positive attitude. Second, customer orientation had a significant effect on customer relationship management performance (customer relationship commitment, corporate image, and customer loyalty). In other words, customer orientation increases commitment to customer relationships. For example, employees who have a customer-orientated perspective provide good service to their customers, while employees who don't have a customer-orientated perspective can't satisfy their customers. Customer orientation can also generate a good image among customers, because they evaluate the image of a hotel through the behavior of hotel employees. So it is very important for employees to show excellent customer orientation. Conclusions - It is very important for hotel CEOs to manage their employees' emotional intelligence. In order to increase their employees' emotional intelligence abilities, CEOs have to manage the overall corporate culture and reward programs to achieve what they want. This is because the system can lead to a customer-orientated mind-set and CRM performance among employees. As a result, the hotel CEO has to pay attention to the emotional intelligence of employees to achieve strong CRM performance. The sentence as originally written was a bit unclear. If this edit does not retain your intended meaning please consider: "Only emotion control does not have a significant impact on customer orientation, and therefore on the ability of an employee to solve customer problems, because it is a passive behavior." Please use the version of the sentence that best captures your original meaning.

  • PDF