• Korean Journal of Optics and Photonics
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• v.21 no.1
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• pp.21-25
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• 2010

In this paper, in order to enhance the image reconstruction performance of white light scanning interferometry(WLI), we demonstrate the scattered point noise filtering performance of post-processing methods. Median filtering is similar to using an averaging filter. Because the median value is less sensitive than the mean to extreme values, the median filter can remove the scattered point noise from a height-map without significantly reducing the sharpness of the image. In several specific cases, however, the median filter can't remove the scattered point noise. Therefore, we propose a comparative mean filter that uses order-statistic filtering and the mean of the neighborhood pixels. The performance is demonstrated by measuring an array of metal solder balls fabricated on PCB. The proposed method reduced the noise pixels by 4.4 percent.

• Journal of the HCI Society of Korea
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• v.1 no.1
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• pp.53-61
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• 2006

In this paper, we propose a novel method for 3D reconstruction of an indoor scene using a multi-view camera. Until now, numerous disparity estimation algorithms have been developed with their own pros and cons. Thus, we may be given various sorts of depth images. In this paper, we deal with the generation of a 3D surface using several 3D point clouds acquired from a generic multi-view camera. Firstly, a 3D point cloud is estimated based on spatio-temporal property of several 3D point clouds. Secondly, the evaluated 3D point clouds, acquired from two viewpoints, are projected onto the same image plane to find correspondences, and registration is conducted through minimizing errors. Finally, a surface is created by fine-tuning 3D coordinates of point clouds, acquired from several viewpoints. The proposed method reduces the computational complexity by searching for corresponding points in 2D image plane, and is carried out effectively even if the precision of 3D point cloud is relatively low by exploiting the correlation with the neighborhood. Furthermore, it is possible to reconstruct an indoor environment by depth and color images on several position by using the multi-view camera. The reconstructed model can be adopted for interaction with as well as navigation in a virtual environment, and Mediated Reality (MR) applications.

• Journal of Biomedical Engineering Research
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• v.32 no.3
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• pp.237-244
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• 2011

In this paper, a feature-based registration technique is proposed for pre-contrast and post-contrast lung CT images. It utilizes three dimensional(3-D) features with their descriptors and estimates feature correspondences by nearest neighborhood matching in the feature space. We design a transformation model between the input image pairs using a free form deformation(FFD) which is based on B-splines. Registration is achieved by minimizing an energy function incorporating the smoothness of FFD and the correspondence information through a non-linear gradient conjugate method. To deal with outliers in feature matching, our energy model integrates a robust estimator which discards outliers effectively by iteratively reducing a radius of confidence in the minimization process. Performance evaluation was carried out in terms of accuracy and efficiency using seven pairs of lung CT images of clinical practice. For a quantitative assessment, a radiologist specialized in thorax manually placed landmarks on each CT image pair. In comparative evaluation to a conventional feature-based registration method, our algorithm showed improved performances in both accuracy and efficiency.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.803-813
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• 2013

The purchase of items in e-commerce is a little bit different from that of items in off-line. The recommendation of items in off-line is conducted by salespersons' recommendation, However, the item recommendation in e-commerce cannot be recommended by salespersons, and so different types of methods can be recommended in e-commerce. Recommender system is a method which recommends items in e-commerce. Preferences of customers who want to purchase new items can be predicted by the preferences of customers purchasing existing items. In the recommender system, the items with estimated high preferences can be recommended to customers. The algorithm of collaborative filtering is used in recommender system of e-commerce, and the list of recommended items is made by estimated values, and then the list is recommended to customers. The dataset used in this research are 100k dataset and 1 million dataset in Movielens dataset. Similar results in two dataset are deducted for generalization. To suggest a new algorithm, distribution features of estimated values are analyzed by the existing algorithm and transformed algorithm. In addition, respondent'distribution features are analyzed respectively. To improve the collaborative filtering algorithm in neighborhood recommender system, a new algorithm method is suggested on the basis of existing algorithm and transformed algorithm.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.117-126
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• 2015

Forest statistics of local administrative districts have many social needs, nevertheless we have some difficulties for working out an accurate statistics because of insufficient data in small-area level. Thus, new small-area estimation method has to set aside additional data, decrease errors of statistics and consider the local forest characteristics at the same time. In this study, we researched the spatial divisions that can set aside additional data for statistics production and satisfy the major premise, which is "forest characteristics of spatial divisions have to be equal to that of small-area". And we compared synthetic estimation methods based on three different spatial divisions(provinces, neighbor districts and new expanded districts). New expanded districts were divided based on the criteria of climate, soil type and tree species composition that affects local forest characteristics. Small-area statistics were assessed in terms of the ability to estimate local forest characteristics and consistency within large-area statistics. As a result, new expanded districts synthetic estimation was assessed to calculate statistics that reflects local forest characteristics better than other two estimation methods. Moreover, this synthetic estimation method produced the statistics that was included within 95% confidence interval of large-area statistics and was the closer to large-area statistics than the neighbor districts synthetic estimation.

• Journal of the Korean Geographical Society
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• v.39 no.6 s.105
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• pp.907-921
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• 2004

Lots of characteristics such as dwelling, neighborhood, and accessibility characteristics affect to the housevalue. Many researches have been done to identify values of each characteristic using hedonic technique. However, there is a limit to identify interaction of each characteristic and variation of each characteristic among the accessibility context. This paper has implemented the Expansion Method research paradigm to model the housevalue determination process in the city of Seoul. The findings of this paper have revealed the presence of contextual variations in the housevalue determination process. The initial model for housevalue reveals that as $F_1$ increases (i.e., larger the number of rooms/bathrooms, larger parking space) and/or $F_2$ increases (i.e., higher owner occupied housing units, higher apartment housing units) and/or $F_3$ increases, (i.e., higher the ratio of higher than college graduated households, 8 school zone, older housing units) the estimated housevalue increases. However, the above relationships drift across their respective contexts. The houses which have negative $F_1$ value, the housevalue does not fluctuate according to the distance to the city center or subcenters. However, the houses which have positive $F_1$ value, the closer to the subcenters or shorter to the river, the higher the estimated housevalues. On the other hand, in areas far from the subcenters, the estimated housevalues does not fluctuate much according to the corresponding $F_2$ level. In areas close to the subcenters, the estimated housevalues vary tremendously according to the $F_2$ value. In the residual analysis, it is revealed that large apartment which are located in Kangnam, IchongDong, MokDong are underestimated. This paper has contributed to our understanding of the housevalue determination process by providing an alternative conceptualization to the traditional approach.

• Korean Journal of Veterinary Service
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• v.44 no.2
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• pp.93-102
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• 2021

In this study, a total of 9,449 hard ticks were collected once a month from April to October 2020 from a neighborhood park in Daejeon by flagging & dragging method and CO₂ manned trap method. The collected ticks were classified according to the Yamagutsi search table using a stereoscopic microscope and molecular biological analysis of four pathogens (SFTSV, Anaplasma spp., Ehrlichia spp., Borrellia spp.). As a result of the study, Haemaphysalis longicornis were collected the most in all areas of the five boroughs at a rate of 82 to 96 percent, while adults were collected the most in May to July, nymphs were collected the most in April to June, and larvae from August to October at a rate of 78 percent to 98 percent. In pathogens, three cases of SFTSV were detected, showing a minimum infection rate (MIR) of 0.46%, while Anaplasma spp. and Ehrlichia spp. were detected one each, with 0.15% and Borrelia spp. with a minimum infection rate of 0.46%. The detected SFTSV showed 99.9% homogeneity with the KF781490 detected in Cheongwon-gun, Chungbuk Province, Anaplasma spp. showed 99.0% homogeneity with JN990105 detected in China, and Erhlichia spp. showed 98.9% genetic similarity with U96436 separated from the U.S. In this study, the distribution status and pathogen infection rate of the hard ticks in the Daejeon area are analyzed and provided as basic data for the prevention of the hard tick-borne infectious disease.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4543-4550
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• 2012

The purpose of this paper is to suggest the improvement method to achieve the interactive development effect between high-tech industrial complex and its surrounding areas. For this reason, this paper has conducted an empirical analysis to find out relevant comprehensive factors, affecting nearby housing prices from such plans, especially by reviewing 'Seoul Digital Industrial Complex.' This paper is truly differentiated from previous research by adding a new perspective 'diverse location characteristics', as it focuses not only on 'high-tech facility' characteristics, but also on 'urban function facilities', including 'transportation facilities', 'amenity facilities', 'security facilities', etc. Then, SPSS Version 18.0 was utilized to conduct the multiple regression analysis with the accumulated relevant data and several results were drawn out as following: Firstly, 'deterioration level', 'brand of apartment', etc. are found to be major influencing factors. Secondly, 'educational facilities', 'transportation facilities', 'Cultural & Sports facilities', 'Amenity facilities', etc. are found in the sector of 'location characteristic'. Lastly, 'leading companies within the industrial complex', were also found, affecting nearby housing prices. Therefore, when a housing development project is planned to grant the interactive development effect to high-tech industrial complex and its surrounding housing areas, it is necessary to consider variety factors, such as comprehensive location characteristics and housing complex characteristics, and also proper housing policy measures should be devised in accordance with the actual demand of employees and their dependant family members.

• Journal of Korean Academy of Nursing
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• v.28 no.2
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• pp.498-509
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• 1998

The phrases such as elders' powerless soliloquy or stammering and their positions unadjusted to the real world are, so far, one of negative views on elder's reminiscences. In other words, it means that elders can get psychological consolation from the getting themselves absorbed in their past. The starting point of this study is, however, that elders' reminiscence are their own mode of the existence. This dissertation is studied through Van Manen's phenomenological research method. The aim of this study is to examine the nature of Korean elders' reminiscences by both observing and describing the reminiscing content in everyday life of elders. The research participants consist of the ten elders who are community elders, hospitalized elders and nursing home residents. The period of the research is about a year from Jan., 1996 to Feb., 1997. The results of this study are as follows : The natures of elders' reminiscences are the regrecting on their life, mitigating the regrects, the confirmation of the powers and the confirmation of their life's mark. The regrecting on their life is the starting point of elders's reminiscences. Elders have tried to examine their life through reflection on their life that they did not live good life as son and daughter for parents and as parents for children and that they have foolishly lived, on dream that they did not come true, on their learning that they did not unsatisfied. But elders mitigate the regrects. They have felt their limitations of power in the conflict of human relation, the economic matter and the difficult predicament, and have finally accepted their life as it is by conquesting from their tenacity. It is dynamically found that both the regrecting on their life and mitigating of the regrection. And they pursuit the powers. It means the pursuit of the vital powers, the vigorous powers and the competency. Elders have pursued their vitality, vigor and competency through their reminiscences and have wanted to be recognised by others as a powerful being. These have dynamic and compounded aspects. The confirmation of their life's mark refer to through their own situation of health, condition, children, neighbourhood and doing their duty as a human. Elders have confirmed the present value of their being through the reflecting the present, past self, other men around themselves, children, neighborhood and the doing their human duty as a good men. Therefore the results of this study can offer new view on the elders' reminiscences that we have to understand them as a process as what they are, escaping from the simple logic that elders' reminiscence have a positive or a negative effects. Also, this study which have examined the natures of Korean elders' reminiscences can cast a new light on elders' nursing proper for Korean culture.

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.1-7
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• 2018

Electric motors for electric vehicles differ in efficiency characteristics depending on the operation modes, studies for evaluating high efficiency characteristics in low speed and high speed operation modes are very important. Therefore, it is necessary to design method that can change the high torque, high output density, and high efficiency characteristics of driving motors for electric vehicles. In this paper, the diameter ratio of stator and rotor for the interior permanent magnet synchronous motor is change of designed 0.62, 0.65, and 0.68, respectively, and the efficiency characteristics of the entire operation section, average efficiency characteristics of the city driving modes and express highway driving modes are analyzed. As a result of analyzing the efficiency characteristics of the entire operating section, it was confirmed that as the diameter ratio increases, the high efficiency section moves to the low speed and low torque section and the high efficiency section moves to the high speed and low torque neighborhood as the diameter ratio decreases. As a result of analyzing the average efficiency characteristics in the city driving modes and express highway driving modes, the average efficiency of 0.68 model is analyzed to be more efficient than the 0.63 and 0.65 model ratio, and it is confirmed that it is suitable for city driving modes and express highway driving modes.