• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.1
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• pp.99-106
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• 2010

A vertical datum requires an origin, which is a point on the Earth's surface where the height of the point is a defined value(26.6871m). From this origin point, heights (height differences) can be measured to any other point using standard leveling and gravity measurement procedures. However, the leveling network over the Korea bas been established by using the normal gravity instead of the actual gravity values, and the heights for the points are published by National Geographic Information Institute (NGII). This may cause height for especially in the area where high-relief mountains are dominant. Therefore, the height errors caused by using normal gravity instead of actual gravity values are analyzed in this study. Then, the differences between the orthometric heights and the published heights, i.e., normal orthometric height are analyzed.

• Journal of computational fluids engineering
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• v.15 no.2
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• pp.7-13
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• 2010

Flight vehicles such as wheel wells and bomb bays have many cavities. The flow around a cavity is characterized as an unsteady flow because of the formation and dissipation of vortices brought by the interaction between the free stream shear layer and the internal flow of the cavity. The resonance phenomena can damage the structures around the cavity and negatively affect the aerodynamic performance and stability of the vehicle. In this study, a numerical analysis was performed for the cavity flows using the unsteady compressible three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equation with Wilcox's turbulence model. The Message Passing Interface (MPI) parallelized code was used for the calculations by PC-cluster. The cavity has aspect ratios (L/D) of 5.5 ~ 7.5 with width ratios (W/D) of 2 ~ 4. The Mach and Reynolds numbers are 0.4 ~ 0.6 and $1.6{\times}10^6$, respectively. The occurrence of oscillation is observed in the "shear layer and transient mode" with a feedback mechanism. Based on the Sound Pressure Level (SPL) analysis of the pressure variation at the cavity trailing edge, the dominant frequencies are analyzed and compared with the results of Rossiter's formula. The dominant frequencies are very similar to the result of Rossiter's formula and other experimental datum in the low aspect ratio cavity (L/D = ~4.5). In the high aspect ratio cavity, however, there are other low dominant frequencies of the leading edge shear layer with the dominant frequencies of the feedback mechanism.

• Journal of Sasang Constitutional Medicine
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• v.15 no.2
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• pp.58-63
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• 2003

The internet contains enormous informations in various fields and therefore called 'sea of information'. It helps obtain quickly health related information including 'constitutional medicine'. But a lack of evaluation and oversight appear to result in inaccurate and misleading. So by using a series of equipment and www.naver.com, www.yahoo.co.kr, www.empas.com, the typical search engine for internet, the sites are researched by keyword 'constitutional medicine'. The results were classified into six groups as follows; The sites about pratitional Oriental Medical Doctor, private home page, advertisements of goods for health, associations of constitutional medicine, astrology or reading fortune, and etc. The internet is a useful tool that gives informations of health, easy and speedy, to users like as doctors and patients. But accuracy or reliabillity of this informations is mistrust. Especially informations of health are connected to safty of life directly, they must be verificated by the specialist and a criterion, that evaluate the sites it self, should be established.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.4
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• pp.367-380
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• 2011

This paper has focused on deriving a GPS based geodetic network adjustment strategy to continuously determine coordinate sets of the national geodetic control points. After domestic literature review on the topic and overseas case studies about countries that recently reformed their geodetic infrastructure have been carried out, a simplified geodetic network consisting of two layers, namely GPS active and passive network, has been proposed to maximize effectiveness of the network adjustment through reducing the number of the passive points. Furthermore, a GPS data processing and network adjustment procedure has been derived to support the continuous management scheme. While a scheme for the active layer adopts a sequential least squares adjustment based on a multi-baseline, that of the passive layer employs a multi-session adjustment technique with respect to 3-dimensional baseline vectors. Finally, experimental adjustment against a network comprising 24 active and 6,900 passive stations has been performed to demonstrate the efficiency and the effectiveness of the proposed method.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.4
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• pp.13-20
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• 2013

Due to the global warming, international agreements have been propelled by industrialized countries. These days, there are various studies and projects to reduce the carbon emission quantity in South Korea, because South Korea is a strong candidate for a newly industrialized nation by Kyoto Protocol. Therefore, this study arranges plans to create various thematic map by producing database that can manage various datum based on grid spatial objects to manage quantity of forest biomass and carbon dioxide. Moreover, this study designs a system to create forest biomass by using the best method of calculation with LiDAR data and KOMPSAT-2 satellite images. In addition, this study designs a biomass monitoring system for public institutions to register biomass, suggesting actual plans to extract, manage, and utilized forest biomass.

• Journal of The Korean Association of Information Education
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• v.21 no.1
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• pp.89-96
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• 2017

Recently, a number of researches actively focus on the contents and sensitivity of information distributed through SNS as smartphones and SNS gained its popularity. In this paper, we collected online news data about SW education, extracted words after morphological analysis, and analyzed emotions of collected news data by calculating sentimental score of each news datum. Also, the accuracy of the calculated sentimental score was examined. As a result, the number of news related to 'SW education' in the collection period was about 189 per month, and the average of sentimental score was 0.7, which signifies the news related to 'SW education' was emotionally positive. We were positive about the importance of SW education and the policy implementation, but there were negative views on the specific method for the realization. That is, a lack of SW education environment and its education method, a problem related to improvement of SW developers and improvement of their labor conditions, and increase of private education in coding were the factors for the negative viewers.

• Spatial Information Research
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• v.15 no.1
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• pp.81-94
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• 2007

Even though the data of digital cadastral map, stored in the Korea Land Information System(hereinafter referred to as "KLIS") has a wide variety of errors, it has been used in a cadastral surveying field without any compensating work. As a result, it has given rise to a lot of problems when we use this digital cadastral map in the cadastral surveying field. That is why we should analyse the accuracy of digital cadastral map which has been stored in the KLIS. In this context, this paper has been intended to provide acceptable proposals with regards to present operation of KLIS or the cadastral re-survey project in the future by analysing the data of digital cadastral map which is one of the layers of the KLIS. Our study results showed that the accuracy of both the location and area in the present KLIS datum was not satisfactory Therefore, in our own judgment, it is necessary to revise cadastral maps more accurately in order to use in the field of cadastral surveying or in carrying out the cadastral re-survey project.

• Health Policy and Management
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• v.12 no.1
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• pp.84-101
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• 2002

This study collected and analyzed the datum related to consultation fee in National Health Insurance Corporation and characteristics of dental clinics for 819 dental clinics in Daegu and Kyungpook districts to specify the distribution and concentration rate of health insurance consultation fee and the critical elements of insurance consultation fee income. The average health insurance consultation fee per one dental clinics is 77.2 million won and the case of women dentists is 78.7 million won. That is higher than 79.9 million won that the case of man dentist. According to age, under 39 is 85.5 million won that is highest, declining little by little above 60s the number decreased to merely 23.9 million won. And the dentists whose business years from 5 to 10 are the highest and declining gradually. The more of engaging members to dental clinics is the larger the income. The average insurance consultation fee of Daegu province is 69.3 million won, but that of Kyungpook is 89.6 million won. Decile distribution ratio of dental clinics consultation fee income is 0.526 and Gini coefficient is 0.303. Decile distribution ratio of Daegu district is 0.489, Gini coefficient is 0.320. This explain the larger inequality compared with Kyungpook(0.623, 0.273). With age, Gini coefficient of below 39 is 0.260, the higher age is, the larger the number is, up to abode 60 the coefficient is 0.504, the degree of inequality is most extremely. insurance consultation fee and the number of cases of consultation is related to the age of dentists, duration of practice, the number of dentists and staffs engaging and provinces. That is, the lesser the age is, the longer the years of engaging are, the more the number of dentists and staffs we, the larger insurance consultation fee income and the number of cases of consultations we. And the fee fur one case is closely related to age and provinces. The fee for one case is higher in lower age, and that of in Daegu dental clinics is higher than in Kyungpook.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.4
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• pp.354-358
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• 2001

This paper presents a fuzzy neural network model which solves the underutilization problem. This fuzzy neural network has both stability and flexibility because it uses the control structure similar to AHT(Adaptive Resonance Theory)-l neural network. And this fuzzy nenral network does not need to initialize weights and is less sensitive to noise than ART-l neural network is. The learning rule of this fuzzy neural network is the modified and fuzzified version of Kohonen learning rule and is based on the fuzzification of leaky competitive leaming and the fuzzification of conditional probability. The similarity measure of vigilance test, which is performed after selecting a winner among output neurons, is the relative distance. This relative distance considers Euclidean distance and the relative location between a datum and the prototypes of clusters. To compare the performance of the proposed fuzzy neural network with that of Kohonen Self-Organizing Feature Map the IRIS data and Gaussian-distributed data are used.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.4
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• pp.359-365
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• 2001

In this paper, we propose the design methodology of target tracking system using fuzzy basis function expansion(FBFE) based on virus evolutionary genetic algorithm (VEGA). In general, the objective of target tracking is to estimate the future trajectory of the target based on the past position of the target obtained from the sensor. In the conventional and mathematical nonlinear filtering method such as extended Kalman filter(EKF), the performance of the system may be deteriorated in highly nonlinear situation. To resolve these problems of nonlinear filtering technique, by appling artificial intelligent technique to the tracking control of moving targets, we combine the advantages of both traditional and intelligent control technique. In the proposed method, after composing training datum from the parameters of extended Kalman filter, by combining FDFE, which has the strong ability for the approximation, with VEGA, which prevent GA from converging prematurely in the case of lack of genetic diversity of population, and by idenLifying the parameters and rule numbers of fuzzy basis function simultaneously, we can reduce the tracking error of EKF. Finally, the proposed method is applied to three dimensional tracking problem, and the simulation results shows that the tracking performance is improved by the proposed method.