• Journal of the Korean Data and Information Science Society
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• 제15권1호
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• pp.183-191
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• 2004

This paper shows that there are some extra-factors on the evaluation of lecture by students. The extra-factors are sex, day and nighttime, academic year, size of lecture, and grades. And this paper analysis the proportion of the student which put the same mark on all items(same marked proportion).

• 한국시뮬레이션학회논문지
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• 제14권2호
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• pp.15-24
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• 2005

The goal of a distributed simulation such as battle field simulation is to combine all kinds of simulations in the same synthetic environment and to make people interact at the same time. It is a key issue to share the same synthetic environment among simulations. To support reusability and affordability in the modeling and simulation area, DMSO(Defense Modeling and Simulation Office) of USA developed concepts such as HLA(High Level Architecture) and SEDRIS (Synthetic Environmental Data Representation and Interchange Specification). In the industrial simulation area, the digital manufacturing is the main stream. To reduce cost and to reuse simulation environment, the standardization becomes the focus of digital manufacturing. This study proposes to use SEDRIS to improve interoperability of manufacturing data. The simulation data of DELMIA, which is a leading commercial digital manufacturing solution, is mapped and translated into the SEDRIS transmittal format. Mapping of the manufacturing simulation data and the synthetic environment are implemented and verified through experiments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.237-252
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• 2017

In recent years, data centers have become the core infrastructure to deal with big data processing. For these big data applications, network transmission has become one of the most important factors affecting the performance. In order to improve network utilization and reduce job completion time, in this paper, by real-time monitoring from the application layer, we propose job-aware priority scheduling. Our approach takes the correlations of flows in the same job into account, and flows in the same job are assigned the same priority. Therefore, we expect that flows in the same job finish their transmissions at about the same time, avoiding lagging flows. To achieve load balancing, two approaches (Flow-based and Spray) using ECMP (Equal-Cost multi-path routing) are presented. We implemented our scheme using NS-2 simulator. In our evaluations, we emulate real network environment by setting background traffic, scheduling delay and link failures. The experimental results show that our approach can enhance the Hadoop job execution efficiency of the shuffle stage, significantly reduce the network transmission time of the highest priority job.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.79-82
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• 2005

Recently the necessity of road data is still being increased in industrial society, so there are many repairing and new constructions of roads at many areas. According to the development of government, city and region, the update and acquisition of road data for GIS (Geographical Information System) is very necessary. In this study, the fusion method with range data(3D Ground Coordinate System Data) and Intensity data in stand alone LiDAR data is used for road extraction and then digital image processing method is applicable. Up to date Intensity data of LiDAR is being studied. This study shows the possibility method for road extraction using Intensity data. Intensity and Range data are acquired at the same time. Therefore LiDAR does not have problems of multi-sensor data fusion method. Also the advantage of intensity data is already geocoded, same scale of real world and can make ortho-photo. Lastly, analysis of quantitative and quality is showed with extracted road image which compare with I: 1,000 digital map.

• 한국해양공학회지
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• 제37권1호
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• pp.38-48
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• 2023

To maintain the existing systems of ships and introduce autonomous operation technology, it is necessary to improve situational awareness through the sensor fusion of the automatic identification system (AIS) and automatic radar plotting aid (ARPA), which are installed sensors. This study proposes an algorithm for determining whether AIS and ARPA signals are sent to the same ship in real time. To minimize the number of errors caused by the time series and abnormal phenomena of heterogeneous signals, a tracking method based on the combination of the unscented Kalman filter and probabilistic data association filter is performed on ARPA radar signals, and a position prediction method is applied to AIS signals. Especially, the proposed algorithm determines whether the signal is for the same vessel by comparing motion-related components among data of heterogeneous signals to which the corresponding method is applied. Finally, a measurement test is conducted on a training ship. In this process, the proposed algorithm is validated using the AIS and ARPA signal data received by the voyage data recorder for the same ship. In addition, the proposed algorithm is verified by comparing the test results with those obtained from raw data. Therefore, it is recommended to use a sensor fusion algorithm that considers the characteristics of sensors to improve the situational awareness accuracy of existing ship systems.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.257-262
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• 2004

The purpose of data fusion is collecting maximized information from combining the data attained from more than two same or different kind sensor systems. Data fusion of same kind sensor systems like optical imagery has been on focus, but recently, LIDAR emerged as a new technology for capturing rapidally data on physical surfaces and the high accuray results derived from the LIDAR data. Considering the nature of aerial imagery and LIDAR data, it is clear that the two systems provide complementary information. Data fusion is consisted of two steps, alignment and matching. However, the complementary information can only be fully utilized after sucessful alignment of the aerial imagery and lidar data. In this research, deal with centroid of building extracted from lidar data as control information for estimating exterior orientation parameters of aerial imagery relative to the LIDAR reference frame.

• International journal of advanced smart convergence
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• 제10권4호
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• pp.263-272
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• 2021

At a time when securing driving safety is the most important in the development and commercialization of autonomous vehicles, AI and big data-based algorithms are being studied to enhance and optimize the recognition and detection performance of various static and dynamic vehicles. However, there are many research cases to recognize it as the same vehicle by utilizing the unique advantages of radar and cameras, but they do not use deep learning image processing technology or detect only short distances as the same target due to radar performance problems. Radars can recognize vehicles without errors in situations such as night and fog, but it is not accurate even if the type of object is determined through RCS values, so accurate classification of the object through images such as cameras is required. Therefore, we propose a fusion-based vehicle recognition method that configures data sets that can be collected by radar device and camera device, calculates errors in the data sets, and recognizes them as the same target.

• 설비공학논문집
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• 제15권1호
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• pp.73-85
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• 2003

Four different methods of reducing the heat transfer coefficients from experimental data under dehumidifying conditions are compared. The four methods consist of two different heat and mass transfer models and two different fin efficiency models. Data are obtained from two heat exchanger samples having plain fins or wave fins. Comparison of the data with the reduction methods revealed that the single potential heat and mass transfer model yielded the humidity independent heat transfer coefficients. Two different fin efficiency models - enthalpy model and humidity model - yielded approximately the same fin efficiencies and accordingly approximately the same heat transfer coefficients. The heat transfer coefficients under wet conditions were approximately the same as those of the dry conditions for the plain fin configuration. For the wave fin configuration, however, wet surface heat transfer coefficients were approximately 12% higher. The pressure drops of the wet surface were 10% to 45% larger than those of the dry surface.

• 한국컴퓨터정보학회논문지
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• 제13권3호
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• pp.99-106
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• 2008

최근 다양한 분야에서(웹 포털, 유료 음원서비스 등) 디지털 음악의 검색이 사용되고 있다. 기존의 디지털 음악의 검색은 음악 데이터에 포함된 자체 메타 정보를 이용하여 이루어진다. 하지만 메타 정보가 다르게 작성되었거나 작성되지 않은 경우 정확한 검색은 어렵다. 요즘 이러한 문제의 보완 방안으로 음악자체를 이용하는 내용기반정보 검색 기법에 대한 연구가 이루어지고 있다. 본 논문에서는 음악의 파형에서 추출된 특징 정보간의 유사도 측정을 통하여 동일음원을 인식하는 방법에 대해 논하고자 한다. 디지털 음악의 특징 정보는 단순화시킨 MFCC (Mel Frequency Cepstral Coefficient)를 이용하여 음악의 파형으로부터 추출하였다. 디지털 음악간의 유사도는 Vision 및 Speech Recognition 분야에서 사용되던 DTW (Dynamic Time Warping) 기법을 활용하여 측정하였다. 제안된 동일 음원 인식 방법의 검증을 위한 같은 장르에서 무작위 추출된 1000곡에서 시행한 500번의 검색은 모두 성공했다. 검색에 사용된 500개의 디지털 오디오는 60개의 디지털음원을 압축방식과 비트율을 다르게 조합하여 만들었다. 실험의 결과로 DTW을 이용한 유사도 측정법이 동일음원을 인식할 수 있음을 증명하였다.

• 한국산학기술학회논문지
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• 제9권6호
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• pp.1666-1672
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• 2008

USN 미들웨어는 여러 사이트에서 발생하는 센서 정보를 수집하여, 판단하고, 조치를 취하는 기능을 가지고 있다. 한 개 센서 데이터로부터 상황을 결정하는 것은 해당 데이터의 오류나 전체를 반영하지 않을 수 있기 때문에 부적절하다. 여기서는 이러한 문제를 해결하기 위하여 '그룹'이라는 개념을 도입하였다. 그룹은 같은 장소에 같은 조건에 행동하는 센서의 집합이다. 예를 들어 특정 방에서 모든 화재 센서는 미리 정의된 동일한 특정 온도에 도달하면 버저를 울린다. 이때 이들 센서들은 동일한 한 개의 그룹에 속하는 것이다. 지능형 USN 미들웨어의 모든 판단은 이러한 그룹에 기반하여 이루어진다. 본 연구에서는 그룹에 기반한 미들웨어의 지능형 규칙에 대하여 연구를 하였다.