• 융합정보논문지
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• 제10권9호
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• pp.15-21
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• 2020

본 논문은 다수의 전자전 센서에서 추출된 시간지연 차이정보와 도플러주파수 차이정보를 이용하는 Two-step weighted least-squares 기반의 이동 신호원 위치 및 속도 추정 기법에서, 수집 정보의 이상치를 검출하는 알고리즘을 제안하고자 한다. 다수의 전자전 센서에서 추출되는 정보는 다양한 요인에 의해 정보에 이상치가 발생할 수 있으며, 이를 효과적으로 검출하고 데이터 융합과정에서 이상치를 배제하여 이동 신호원의 위치와 속도 추정의 정확도를 높이고자 한다. 본 논문에서는 이상치를 제외한 최소의 정상치 정보 집합을 추출하고, 이를 기반으로 나머지 정보의 이상치 여부를 확률적으로 판단하는 알고리즘을 제안하였으며, 이를 모의실험을 통해, 정보의 이상치가 효과적으로 제거되어 위치 및 속도 추정의 정확도를 향상시킬 수 있음을 확인하였다. 정상치 거리정보 잡음이 20dB 이하인 경우, 이상치 정보를 효과적으로 제거하여, Cramér-Rao lower bound에 근접한 위치 및 속도 추정 정확도를 얻음을 확인하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.729-734
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• 2004

The e-Logistics means the virtual business activity and service architecture among the logistics companies based on the Internet technology. The management of vehicles' location in most conventional vehicle tracking system has some critical defects when it deals with data which are continuously changed. It means the conventional vehicle tracking system based on the conventional database is unable eventually to cope with the environment that should manage the frequently changed location of vehicles. The important things in the evaluation of the vehicle tracking system is to determine the threshold of cost of database ,update period and communication period between vehicles and the system. In other words, the difference between the reallocation of vehicle and the data in database can evaluate the overall performance of vehicle tracking systems. Most of the previous works considers only the information that is valid at the current time, and is hard to manage efficiently the past and future information. To overcome this problem, the efforts on moving objects management system(MOMS) and uncertainty processing have been started from a few years ago. In this paper, we propose an uncertainty processing model and system implementation of moving object that tracks the location of the vehicles. We adopted both linear-interpolation method and trigonometric function to chase up the location of vehicles for the past time as well as future time, respectively. We also explain the comprehensive examples of MOMS and uncertainty processing in parcel application that is one of major application of e-Logistics domain.

• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2106-2117
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• 2017

An effective statistical feature extraction approach of data sampling of fault in the combined transmission system is presented in this paper. The proposed algorithm leads to high accuracy at minimum cost to predict fault location and fault type classification. This algorithm requires impedance measurement data from one end of the transmission line. Modal decomposition is used to extract positive sequence impedance. Then, the fault signal is decomposed by using discrete wavelet transform. Statistical sampling is used to extract appropriate fault features as benchmark of decomposed signal to train classifier. Support Vector Machine (SVM) is used to illustrate the performance of statistical sampling performance. The overall time of sampling is not exceeding 1 1/4 cycles, taking into account the interval time. The proposed method takes two steps of sampling. The first step takes 3/4 cycle of during-fault and the second step takes 1/4 cycle of post fault impedance. The interval time between the two steps is assumed to be 1/4 cycle. Extensive studies using MATLAB software show accurate fault location estimation and fault type classification of the proposed method. The classifier result is presented and compared with well-established travelling wave methods and the performance of the algorithms are analyzed and discussed.

• 전기학회논문지
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• 제62권4호
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• pp.562-565
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• 2013

A new variable rate speech coding technique is proposed. The method is based on the observation that the speech signal approximately looks linear for a very short period of time. The information transmitted is the location and data value of inflection points. If the distance between the inflection points is large, the mid point location and its data value are also delivered. Thus, the encoder transmits both the location and the data value for the inflection samples, but the location only for the non-inflection points. The location information is expressed using one bit for each sample, 0 for non-inflection and 1 for inflection point. At the receiver, using the interpolation, the decoder estimates the untransmitted sample values for non-inflection locations from the received sample values for the inflection samples. With 50 % of computational cost of the existing CVSD delta modulation, the proposed method is expected to achieve the data rate of 36 to 38 kbps and the SNR of 10 to 13 dB.

• 한국멀티미디어학회논문지
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• 제24권12호
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• pp.1682-1692
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• 2021

Digital Twin, one of the core technologies of the Fourth Industrial Revolution, is attracting attention as a very suitable technology for disaster monitoring such as fires and earthquakes. In this paper, we implement a system equipped with UWB RTLS(Ultra-Wideband Real Time Location System), real-time remote control, and video streaming, which are element technologies for disaster monitoring digital twin. Since the proposed system structure is based on a cloud server, the actual location of the UWB indoor positioning-based client is transmitted to the user device in real time and stored on the cloud server for statistical and data analysis. In addition, we demonstrate through experiments that outliers occurs when the value of RSSI(Received Signal Strength Indicator) decreases due to communication collisions between UWB Tags, and propose an RSSI outlier correction algorithm to solve this problem.

• Steel and Composite Structures
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• 제36권5호
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• pp.521-531
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• 2020

The behavior variation of concrete dam is investigated, based on a new method for analyzing the data model of concrete dam in service process for the limitation of wavelet transform for solving concrete dam service process model. The study takes into account the time and position of behavior change during the process of concrete dam service. There is no dependence on the effect quantity for overcoming the shortcomings of the traditional identification method. The panel data model is firstly proposed for analyzing the behavior change of composite concrete dam. The change-point theory is used to identify whether the behavior of concrete dams changes during service. The phase space reconstruction technique is used to reconstruct the phase plane of the trend effect component. The time dimension method is used to solve the construction of multi-transformation model of composite panel data. An existing 76.3-m-high dam is used to investigate some key issues on the behavior change. Emphasis is placed on conversion time and location for three time periods consistent with the practical analysis report for evaluating the validity of the analysis method of the behavior variation of concrete dams presented in this paper.

• 한국측량학회지
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• 제34권6호
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• pp.609-618
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• 2016

Since demand for location-based services increases and the relevant service becomes more diverse, the use of POI (Point of Interest) is being required in various fields. Various roles of POI for display, search and inquiry exist, but the implementation and expression of such roles are partially limited. Therefore, the data model for implementation is suggested in this paper to enable practical implementation, expression and inquiry of POI data. The data model was developed based on 3 roles of POI including search, expression and linkage, and especially, the spatial relationship between POI objects which was not suggested in previous data models is considered and time series scheme is suggested to enable various expressions and inquiries in application services.

• 전기학회논문지P
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• 제65권1호
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• pp.18-24
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• 2016

In order to service restoration and enhance power system reliability, a number of impedance based fault location algorithms have been developed for fault locating in a transmission line. This paper presents an advanced impedance-based fault location algorithms in a two-ended sources transmission line to reduce the DC offset error effects. This fault location algorithm uses of the GPS time synchronized voltage and current signals from the local and remote terminal. The algorithm uses an advanced DC offset removal filter. A series of test results using ATPdraw simulation data show the performance effectiveness of the proposed algorithm. The proposed algorithm is valid for a two-end sources transmission network.

• Management Science and Financial Engineering
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• 제14권2호
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• pp.1-12
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• 2008

This study explores several donor location strategies and discusses experiment results, which contributes to the saving of time and effort required in designing data fusion processes. In particular, three concepts are introduced. The Mahalanobis distance is applied to locate the nearest neighbors more effectively; which incorporates the covariance structure of attributes. The ideal point helps reduce the dimensionality problem that arises in conjoint-type experiments. The correspondence analysis is used to derive the coordinates from non-metric attributes. The Monte Carlo simulation results show that the proposed donor location strategies provide better fusion performance, compared to the currently-in-use methods.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.490-491
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• 2021

최근 실내 환경에서 정확한 위치 기반 서비스의 제공을 위해 Wi-Fi 핑거프린트와 딥러닝을 이용한 기술이 연구되고 있다. 이때 학습 데이터의 구성은 매우 중요하며 학습에 필요한 충분한 데이터의 수집은 필수적이다. 그러나 측위가 필요한 영역 내에서 무선 신호 데이터의 수집을 위한 특정 지점의 수는 무한하며 이러한 데이터를 모두 수집하는 것은 불가능하다. 따라서 부족한 학습 데이터를 보충할 수 있는 방법이 필요하다. 본 연구에서는 부족하게 수집된 위치 데이터를 기반으로 학습에 필요한 충분한 수의 위치 데이터의 구성 방법을 제안한다.