• Journal of the Society of Disaster Information
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• v.17 no.2
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• pp.341-350
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• 2021

Purpose: The purpose of this study is to present an analysis method to select priorities for areas where the traffic safety system is applied to reduce pedestrian accidents. Method: Using Kernel density analysis using the coordinate information of the accident point, we performed density analysis of elderly walking accidents and elderly jaywalking accidents, and analysis of the weight of two types of walking accidents. Result: As a result of density analysis of the weight considering elderly jaywalking accidents, it was analyzed that the density of pedestrian traffic accidents for th elderly was higher in Gunsan-si, Jeongeup-si, and Gimje -si compared to Jeonju-si, where the number of elderly pedestrian accidents were high. Conclusion: The analysis results of this study are judged to be possible to use objective indicators for the selection of target sites for the introduction of the traffic safety system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.12 s.243
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• pp.1597-1604
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• 2005

The identification of a moving noise source is important in reducing the source power of the transport systems such as airplanes or high speed trains. However, the direct measurement using a microphone running with noise source is usually difficult due to wind noise, white the source motion distorts the frequency characteristics of the pass-by sound measured at a fixed point. In this study the relationship between the spectra of the source and the pass-by sound signal is analyzed for an acoustic source moving at a constant velocity. Spectrum of the sound signal measured at a fixed point has an integral relationship with the source spectrum. Nevertheless direct conversion of the measured spectrum to the source spectrum is ill-posed due to the singularity of the integral kernel. Alternatively a differential equation approach is proposed, where the source characteristics can be recovered by solving a differential equation relating the source signal to the distorted measurement in time domain. The parameters such as the source speed and the time origin, required beforehand, are also determined only from the frequency-phase relationship using an auxiliary measurement. With the help of the regularization method, the source signal is successfully recovered. The effects of the parameter errors to the estimated frequency characteristics of the source are investigated through numerical simulations.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.5
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• pp.283-294
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• 2004

This paper introduces the new Direct Torque Control(DTC) method based on the estimated torque in Switched Reluctance Motor(SRM) and applies the proposed DTC to SRM for the instantaneous torque ripple reduction. The nonlinear characteristics of SRM is considered in the calculation of the estimated torque and the theory is described in this paper. Current control is one of the kernel elements of torque controller and the performance of the current control should be high for this work. But the conventional PI current control has a weak point in SRM application because of motional EMF. Consequently, this paper makes up for the weakness of PI controller through present of new current controller, that is termed the non-interference current control. The ability of proposed torque and current controller is verified through simulation and experiment.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.1
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• pp.101-110
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• 2003

Motorcycle industry, for its competitive position, depends on part design technology. This part design has a bulky amount of data and asks the accumulation of advanced technical skill and experience, and fragmentary technical application is not enough to get to the kernel of a problem. Therefore, the improvement of proper productivity - the starting point of engineering design - and useful Design Methodology for products manufacturing are needed. Thus this paper is aimed to create a program that outputs dynamic characteristics of a vehicle when the data from fully understanding on motorcycle's brake system and induced formula for brake design are inputted. This paper is intended to show a creative design method by the thermal analysis data through FEM study and using shape design parameters derived from our programs.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.26.3-26
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• 2001

Van de Vusse reactor is known as a highly nonlinear chemical process and has been considered by a number of researchers as a benchmark problem for nonlinear chemical process. Various identification methods for nonlinear system are also verified by applying these methods to Van de Vusse reactor. From the point of view of identification, only the Volterra kernel of second order has been obtained until now. In this paper, the authors show that Volterra kernels of nonlinear Van de Vusse reactor of up to 3rd order are obtained by use of M-sequence correlation method. A pseudo-random M-sequence is applied to Van de Vusse reactor as an input and its output is measured. Taking the cross correlation function between the input and the output, we obtain up to 3rd order Volterra kernels, which is ...

• Bulletin of the Society of Naval Architects of Korea
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• v.24 no.1
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• pp.1-8
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• 1987

It is shown that irregular frequencies in the source and doublet distribution method, can be eliminated if the Green function associated with Kelvin's source of pulsating strength, is modified only in the region inside the body at the level of the undisturbed free surface. The system of the resulting Green integral equation is augmented without loss of the square-integrable property of its kernel so hat the discretisation yield N linearly independent equations for N unknown variables. From the solution, the potential and velocity at any point on the wetted surface of a surface-piercing body can be found using the properties of the double layer composed of the source and normal doublet distribution.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.271-273
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• 2015

The bulk motion of star clusters can be determined after careful membership analysis using parametric or non-parametric approaches. This study aims to implement non-parametric membership analysis based on Binned Kernel Density Estimators which takes into account measurements errors (simply called BKDE-e) to determine the average proper motion of each cluster. This method is applied to 178 selected star clusters with angular diameters less than 20 arcminutes. Proper motion data from UCAC4 are used for membership determination. Non-parametric analysis using BKDE-e successfully determined the average proper motion of 129 clusters, with good accuracy. Compared to COCD and NCOVOCC, there are 79 clusters with less than $3{\sigma}$ difference. Moreover, we are able to analyse the distribution of the member stars in vector point diagrams which is not always a normal distribution.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.2
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• pp.65-74
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• 2013

A research program for the roe deer (Capreolus pygargus) has been set up at the Jeju Experimental Forest of Warm-temperate and Subtropical Forest Research Center in Jeju Island. To explore the home range size and habitat environment, 3 males and 3 females have been captured and released with GPS-CDMA based telemetry since 24th April 2012. Among them 2 females were captured at Hannam Forest of Seoguipo, were pregnant and monitored by the tracking system. There are significantly different patterns in behavior around the parturition. After parturition they show recurrence behavior toward one point in the forest, while they have irregular patterns in moving before. To calculate the home range size, the MCP (minimum convex polygon) and Kernel Method are applied through the extension of ESRI ArcView GIS 3.2a. The pregnant female captured 9th May 2012 has the size of MCP=67ha and Kernel 95%=0.5ha and the pregnant female captured 12th July 2012 has the size of MCP=82ha and Kernel 95%=0.9ha. Although a fawn could move immediately just after the birth likely others to avoid any risks, they stay at very narrow space significantly, and the size become wider when more time goes by. Furthermore, they mainly have a home range away from human activity area such as forest tracking roads. The habitat environment for the parturition is summarized as 40years old cryptomeria forests with new sprouting shrubs for foods, which are the controlled forest through the thinning and removing shrubs 2 years ago. This means that forest works could cause positive results for the parturition and survival of young. The period of parturition is earlier than highland in Jeju Island, the size of home range is narrower than other countries, and the habitat environment of the shelter for a fawn is similar to previous research in other countries.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.4
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• pp.803-810
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• 2017

Recently, social security problems have been caused by the development of the software industry, and a variety of automation techniques have been used to verify software stability. In this paper, we propose a method of automatically detecting a use-after-free vulnerability on Windows system calls using dynamic symbolic execution, one of the software testing methods. First, a static analysis based pattern search is performed to select a target point. Based on the detected pattern points, we apply an induced path search technique that blocks branching to areas outside of interest. Through this, we overcome limitations of existing dynamic symbolic performance technology and verify whether vulnerability exists at actual target point. As a result of applying the proposed method to the Windows system call, it is confirmed that the use-after-free vulnerability, which had previously to be manually analyzed, can be detected by the proposed automation technique.

• Journal of Internet Computing and Services
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• v.6 no.3
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• pp.159-170
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• 2005

OC-SVM(One Class Support Vector Machine) avoids solving a full density estimation problem, and instead focuses on a simpler task, estimating quantiles of a data distribution, i.e. its support. OC-SVM seeks to estimate regions where most of data resides and represents the regions as a function of the support vectors, Although OC-SVM is powerful method for data description, it is difficult to incorporate human subjective importance into its estimation process, In order to integrate the importance of each point into the OC-SVM process, we propose a fuzzy version of OC-SVM. In FOC-SVM (Fuzzy One-Class Support Vector Machine), we do not equally treat data points and instead weight data points according to the importance measure of the corresponding objects. That is, we scale the kernel feature vector according to the importance measure of the object so that a kernel feature vector of a less important object should contribute less to the detection process of OC-SVM. We demonstrate the performance of our algorithm on several synthesized data sets, Experimental results showed the promising results.