• Journal of Welding and Joining
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• v.28 no.1
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• pp.54-59
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• 2010

Ship Blocks are assembled by welding, and among them, welding between large blocks (Pre-erection stage) is used as feature of butt. In this process, local material has a experience of thermal cycle and become finally shrunk. As for inconsistency of shrunk weldments and adjacent regions, ship structure would be deformed locally and globally. Thermal distortion analyses are done for control of these processes, and methodologies capable of ship block size among them are using 2-D shell element in FEM. A shell element takes charge of plate, so it has its thickness which is important for angular distortion by welding. By the way, a butt-welding consists normally of several passes, and weldment thickness are different at each pass. If a calculated final one-time welding shrinkage is acting on the shell element whose thickness is same as it of plate, then deformation value must be underestimated. This research developed a methodology that total deformation after multi-pass welding can be analyzed by one time at shell element having original thickness of its plate. We use the SDB thermal distortion analysis method and verified by several experiment. The both experimental and analysis results showed good agreements.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.1
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• pp.79-90
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• 2014

Objectives: The aim of this study was to suggest preliminary data for the establishment of communication methodology of asbestos risk, fit for the features of each audiences, by grasping the features of risk communication by each element for each group survey. Methods: For this study, a questionnaire survey has been conducted from May to August 2012 and responses of 617 people including 214 school asbestos managers, 95 asbestos business managers, and 308 general public have been analyzed. Results: The feature by element of risk communication shows that to give information through non-governmental organizations with reliability such as colleges, research institutes, asbestos-related associations, etc among the entire investigated groups, is most effective. Lastly, for stakeholders related to asbestos, the public feedback for governmental asbestos management policy shows that it was considered that there is lack of reality due to comprehension deficit for situation, lack of a system of asbestos general management in the country and lack of policy connectivity among the branches of the government, and between the central government and the local government. However, the general public selected lack of various information disclosure, education, publicity for asbestos and lack of communication with citizens as the biggest problems.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.3
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• pp.21-28
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• 2017

The main goal of this paper is to assess application of UAV (Unmanned Aerial Vehicle) remote sensing and GIS based images in detection and measuring of rice field drought area in South Korea. Drought is recurring feature of the climatic events, which often hit South Korea, bringing significant water shortages, local economic losses and adverse social consequences. This paper describes the assesment of the near-realtime drought damage monitoring and reporting system for the agricultural drought region. The system is being developed using drought-related vegetation characteristics, which are derived from UAV remote sensing data. The study area is $3.07km^2$ of Wonbuk-myeon, Taean-gun, Chungnam in South Korea. UAV images were acquired three times from July 4 to October 29, 2015. Three images of the same test site have been analysed by object-based image classification technique. Drought damaged paddy rices reached $754,362m^2$, which is 47.1 %. The NongHyeop Agricultural Damage Insurance accepted agricultural land of 4.6 % ($34,932m^2$). For paddy rices by UAV investigation, the drought monitoring and crop productivity was effective in improving drought assessment method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5624-5638
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• 2016

A novel method based on Surf points is proposed to detect and lock-track single ground target in aerial videos. Videos captured by moving cameras contain complex motions, which bring difficulty in moving object detection. Our approach contains three parts: moving target template detection, search area estimation and target tracking. Global motion estimation and compensation are first made by grids-sampling Surf points selecting and matching. And then, the single ground target is detected by joint spatial-temporal information processing. The temporal process is made by calculating difference between compensated reference and current image and the spatial process is implementing morphological operations and adaptive binarization. The second part improves KALMAN filter with surf points scale information to predict target position and search area adaptively. Lastly, the local Surf points of target template are matched in this search region to realize target tracking. The long-term tracking is updated following target scaling, occlusion and large deformation. Experimental results show that the algorithm can correctly detect small moving target in dynamic scenes with complex motions. It is robust to vehicle dithering and target scale changing, rotation, especially partial occlusion or temporal complete occlusion. Comparing with traditional algorithms, our method enables real time operation, processing $520{\times}390$ frames at around 15fps.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2407-2409
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• 2002

강화학습이란 에이전트가 알려지지 않은 미지의 환경에서 행위와 보답을 주고받으며, 임의의 상태에서 가장 적절한 행위를 학습하는 방법이다. 만약 강화학습 중에 에이전트가 과거 문제들을 해결하면서 학습한 환경에 대한 지식을 이용할 수 있는 능력이 있다면 새로운 문제를 빠르게 해결할 수 있다. 이런 문제를 풀기 위한 방법으로 에이전트가 과거에 학습한 여러 문제들에 대한 환경 지식(Domain Knowledge)을 Local state feature라는 기억공간에 학습한 후 행위함수론 학습할 때 지식을 활용하는 방법이 연구되었다. 그러나 기존의 연구들은 주로 2차원 공간에 대한 연구가 진행되어 왔다. 본 논문에서는 환경 지식을 이용한 강화학습 알고리즘을 3차원 공간에 대해서도 수행 할 수 있도록하는 개선된 알고리즘을 제안하였으며, 제안된 알고리즘의 유효성을 검증하기 위해 초소형 비행체의 항공운항 학습에 대해 모의실험을 수행하였다.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.2
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• pp.1-9
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• 2018

In this paper, we propose a face recognition method which is not sensitive to illumination change and prevents false recognition of photographs. The proposed method uses infrared and depth images at the same time, solves sensitivity of illumination change by infrared image, and prevents false recognition of two - dimensional image such as photograph by depth image. Face detection method using infrared and depth images simultaneously and feature extraction and matching method for face recognition are realized. Simulation results show that accuracy of face recognition is increased compared to conventional methods.

• Journal of the Korean Society of Costume
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• v.56 no.9 s.109
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• pp.112-126
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• 2006

In this study, to study the aesthetic properties of the Italy fashion, the internal fashion contents are defined according to the cultural characteristics of Italy and based on the definition, the external features are investigated. The cultural characteristic was analyzed based on the reference literatures on the Italy culture. The aesthetical properties of the contemporary Italy fashion can be analyzed as follows: ${\cdot}$ Functionalism is a feature showing the Italian cultural environment where the genuine humanism is retained. It enables the practical designs by applying details and materials that wouldn't put a limit to the movement of the human body. ${\cdot}$ Naturalism focuses on the natural beauty of the human body without any artificial forms or exaggerated ornaments. Natural texture or materials are used to express the human body itself, or to emphasize the natural aesthetic effects flowing with the human body. ${\cdot}$ Localism is the expression of folk spirit affected by the natural environment. It expresses local atmosphere by unique craftsmanship in material, pattern, color and details. Based on this result, the aesthetic properties of the contemporary France fashion, examined through ${\Iceil}$A Cultural Approach to the Aesthetic Characteristic of the 20th Century French Fashion${\rfloor}$ and those of the contemporary Italy fashion are compared.

• Smart Structures and Systems
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• v.6 no.3
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• pp.335-347
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• 2010

Recent advances in hardware and instrumentation technology have allowed the possibility of deploying very large sensor arrays on structures. Exploiting the huge amount of data that can result in order to perform vibration-based structural health monitoring (SHM) is not a trivial task and requires research into a number of specific problems. In terms of pressing problems of interest, this paper discusses: the design and optimisation of appropriate sensor networks, efficient data reduction techniques, efficient and automated feature extraction methods, reliable methods to deal with environmental and operational variability, efficient training of machine learning techniques and multi-scale approaches for dealing with very local damage. The paper is a result of the ESF-S3T Eurocores project "Smart Sensing For Structural Health Monitoring" (S3HM) in which a consortium of academic partners from across Europe are attempting to address issues in the design of automated vibration-based SHM systems for structures.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.4
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• pp.89-97
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• 2015

In this paper, a method of color image segmentation based on DBSCAN(Density Based Spatial Clustering of Applications with Noise) using compactness of superpixels and texture information is presented. The DBSCAN algorithm can generate clusters in large data sets by looking at the local density of data samples, using only two input parameters which called minimum number of data and distance of neighborhood data. Superpixel algorithms group pixels into perceptually meaningful atomic regions, which can be used to replace the rigid structure of the pixel grid. Each superpixel is consist of pixels with similar features such as luminance, color, textures etc. Superpixels are more efficient than pixels in case of large scale image processing. In this paper, superpixels are generated by SLIC(simple linear iterative clustering) as known popular. Superpixel characteristics are described by compactness, uniformity, boundary precision and recall. The compactness is important features to depict superpixel characteristics. Each superpixel is represented by Lab color spaces, compactness and texture information. DBSCAN clustering method applied to these feature spaces to segment a color image. To evaluate the performance of the proposed method, computer simulation is carried out to several outdoor images. The experimental results show that the proposed algorithm can provide good segmentation results on various images.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1111-1122
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• 2008

Recently, because of decreasing in population, most of local universities are competing to attract new students in the entrance examination. These situations cause that most of the examinee apply for several universities to matriculate in a university. So these problem may raise a serious trouble such as additional new students invited. Therefore, in this study, we consider a few statistical models by using data mining technique to understand the pattern of new students who discard registration(seceders) in spite of success in the D university entrance examination. To construct these models, we use entrance examination data of three years. On the basis for analysis results of entrance examination data, we look into the features for secession of new students who success in an university entrance examination. We provide a basic information to make a effective entrance plan for seceders in future. Also, we make a search for the trend based on three years by analyzing entrance examination data of 2006, 2007 and 2008 years.