• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.4
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• pp.295-303
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• 2018

The stereo camera system has a fixed baseline and therefore has a constant scale. However, it is difficult to measure the actual three-dimensional coordinate since the scale is not fixed when relative orientation parameters are determined through the key-point matching in the stereo image each time. Therefore, the purpose of this study was to perform the stereo camera calibration that simultaneously determines the internal characteristics of the left and right cameras and the camera relationship between them using the modified collinearity equation and compared it with the two independent single cameras calibration. In the experiment using the images taken at close range, the RMSE (Root Mean Square Error) of ${\pm}0.014m$ was occurred when the three dimensional distances were compared in the single calibration results. On the other hand, the accuracy of the three-dimensional distance of the stereo camera calibration was better because the stereo camera results were almost no error compared to the results from two single cameras. In the comparison of the epipolar images, the RMSE of the stereo camera was 0.3 pixel more than that of the two single cameras, but the effect was not significant.

• Journal of Society of Preventive Korean Medicine
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• v.8 no.1
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• pp.1-17
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• 2004

The research method of 'the grafing I-ching(周易) and oriental medicine'(醫易會通) has been handed down for more than 2000 years to interpret the theory of the medicine by using the system of the ideology and the category of I-ching(周易). Many skillful doctors form the past have developed and advanced the oriental medicine by studying the 'the grafing I-ching(周易) and oriental medicine'(醫易會通) and wrote many theories and had experiment on clinical studies. From many theories of 'the grafing I-ching(周易) and oriental medicine'(醫易會通), I believe using the ideology and the category of eight trigrams(八卦) system to study the internal organs(臟腑) has a great importance. For eight trigrams(八卦) is the nucleus or the basic of I-ching(周易) and the internal organs (臟腑) are the main system of the body. Therefore grafting eight trigrams(八卦) and the internal organs (臟腑) theory has a meaning of grafting I-ching(周易) and the main point of the oriental medicine. But the uncertainties of the theories between doctors still exists and there's no unified theories in matching eight trigrams(八卦) and the internal organs(臟腑). This tells us that the most important part of the 'the grafing I-ching(周易) and oriental medicine'(醫易會通) theory is not logically organized. Therefore the author realized the necessity of the study about grafting eight trigrams(八卦) and the intimal organs (臟腑) theory, Also in order to confirm the significance of the result of the research, first of all there needs to be a research that applies it to the meathod of the mental cultivation(精神養生法), Health preservation(養生) is the basic idea of the oriental medicine and among health preservation(養生), the meathod of the mental cultivation(精神養生法) is most important.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5214-5218
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• 2011

In this paper, bandwidth improvement of a series-fed two dipole array(STDA) antenna applicable for mobile communication base station antennas is studied. The proposed STDA antenna consists of two strip dipole antennas with different lengths which are connected directly trough a coplanar stripline(CPS). By adjusting the spacing between the two dipoles and the length of the second dipole, the bandwidth of the STDA can be enhanced. In addition, an integrated balun composed of a short-circuited microstrip line and a slot line is utilized to minimize the area required for a feeding part, and a broadband impedance matching is obtained by adjusting the feeding point. Based on the proposed antenna structure, an STDA antenna covering the frequency band ranging from 1.75 GHz to 2.7 GHz, which includes almost all the existing mobile communication frequency bands, with more than 5 dBi gain is designed and fabricated on an FR4 substrate with dielectric constant of 4.4 and thickness of 1.6mm, and experimentally tested. The fabricated antenna shows impedance bandwidth of 49%(1.7-2.8 GHz) for VSWR<2, a gain higher than 5.5 dBi, and a front-back ratio better than 12 dB.

• The Korean Journal of Archival Studies
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• no.19
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• pp.57-102
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• 2009

Recently, distribution of record via web and coefficient of utilization are increase. so, Archival information service using website becomes essential part of record center. The main point of archival information service by website is making record information retrieval easy. It has need of matching user's request and representation of record resources correctly to making archival information retrieval easy. Archivist and record manager have used various information representation tools from taxonomy to recent thesaurus, still, the accuracy of information retrieval has not solved. This study constructed record retrieval system based on Topic Map by modeling record resources which focusing on description metadata of the records to improve this problem. The target user of the system is general web users and its range is limited to the president related sources in the National Archives Portal Service. The procedure is as follows; 1) Design an ontology model for archival information service based on topic map which focusing on description metadata of the records. 2) Buildpractical record retrieval system with topic map that received information source list, which extracted from the National Archives Portal Service, by editor. 3) Check and assess features of record retrieval system based on topic map through user interface. Through the practice, relevance navigation to other record sources by semantic inference of description metadata is confirmed. And also, records could be built up as knowledge with result of scattered archival sources.

• The Korean Journal of Archival Studies
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• no.3
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• pp.33-64
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• 2001

This essay introduces the basic method and program required to meet some necessary conditions of building university archives. By the phrase 'method and program', I intend the effective means of regularly but circumstantially controling the ways to the archival purposes proper which can be defined as the keeping of evidences and the broadening of information pool in terms of the evidential and informational natures or values of records. My starting point is about the matters of overcoming a standard method of induction which has long prescribed much passive procedures in the archival work. Considering the differences in the records and archives management-practices between West and Korea, I tentatively try to add some active elements to the archival work among which the collection for the expanding evidences and informations may firstly emphasized. While this collecting activity normally depends on the existing 'collections' and 'manuscripts', I cannot exclude the possibility of collections the materials, being likely to be registered in any poor or insufficient record groups. In the similar context, this kind of activity may and must be expanded beyond the university boundaries so at to arrange the cornerstones of archive-based local studies in the various disciplines. Here I premise another role of university archives, the role as 'science archives'. These archives within university archives seem likely to function in likewise the special collections within Western university libraries. What I mean here, however, is the archival groups purposedly gathered or acquisited according to more detail and narrower plan in order to meet the various demands from the different disciplines for the primary sources. The archival procedures from this revised method and program may, I hope, satisfy some of the preconditions of building university archives before the archives will actually function as a sub-institution of an university preserving legal, administrative and financial evidences, thus keeping identity and continuity of the university on the one hand, and as a local information center of supplying the archival contents on effectual demand from the field of local studies on the other. Finally, I conclude with a suggestion concerning the cooperation of all the parties of archival works. Proposing the 'Regional Research Center Program' in the field of technology and engineering as a model for the cooperation, I suggest that universities, private/public organizations, and central and local governments may work together for surveying the scattered ancient and modern documents as well as for building archives under the matching fund.

• Knowledge Management Research
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• v.22 no.2
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• pp.1-17
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• 2021

In this study, we predicted the bitcoin prices of Bithum and Coinbase, a leading exchange in Korea and USA, using ARIMA and Recurrent Neural Networks(RNNs). And we used news articles from each country to suggest a separated RNN model. The suggested model identifies the datasets based on the changing trend of prices in the training data, and then applies time series prediction technique(RNNs) to create multiple models. Then we used daily news data to create a term-based dictionary for each trend change point. We explored trend change points in the test data using the daily news keyword data of testset and term-based dictionary, and apply a matching model to produce prediction results. With this approach we obtained higher accuracy than the model which predicted price by applying just time series prediction technique. This study presents that the limitations of the time series prediction techniques could be overcome by exploring trend change points using news data and various time series prediction techniques with text mining techniques could be applied to improve the performance of the model in the further research.

• Journal of Cadastre & Land InformatiX
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• v.52 no.1
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• pp.69-80
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• 2022

Drone photogrammetry generally acquires images vertically or obliquely from above, so when photographing for the purpose of three-dimensional modeling, image matching for the ground of a building and spatial accuracy of point cloud data are poor, resulting in poor 3D mesh completeness. Therefore, to overcome this, this study analyzed the spatial accuracy of each drone image by acquiring smartphone images from the ground, and evaluated the accuracy improvement and completeness of 3D mesh when the smartphone image is not combined with the drone image. As a result of the study, the horizontal (x,y) accuracy of drone photogrammetry was about 1/200,000, similar to that of traditional photogrammetry. In addition, it was analyzed that the accuracy according to the photographing method was more affected by the photographing angle of the object than the increase in the number of photos. In the case of the smartphone image combination, the accuracy was not significantly affected, but the completeness of the 3D mesh was able to obtain a 3D mesh of about LoD3 that satisfies the digital twin city standard. Therefore, it is judged that it can be sufficiently used to build a 3D model for digital twin city by combining drone images and smartphones or DSLR images taken on the ground.

• Health Policy and Management
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• v.33 no.1
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• pp.3-18
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• 2023

Background: A chronic disease management program including patient education, recall and remind service, and reduction of out-of-pocket payment was implemented in Korea through a chronic care model. This study aimed to assess the effect of a community-based intervention program for improving medication adherence of patients with diabetes mellitus in rural areas of Korea. Methods: We applied a non-equivalent control group design using Korean National Health Insurance Big Data. Hongcheon County has been continuously adopting this program since 2012 as an intervention region. Hoengseong County did not adopt such program. It was used as a control region. Subjects were a cohort of patients with diabetes mellitus aged more than 65 years but less than 85 years among residents for 11 years from 2010 to 2020. After 1:1 matching, there were 368 subjects in the intervention region and 368 in the control region. Indirect indicators were analyzed using the difference-in-difference regression according to Andersen's medical use model. Results: The increasing percent point of diabetic patients who continuously received insurance benefits for more than 240 days from 2010 to 2014 and from 2010 to 2020 were 2.6%p and 2.7%p in the intervention region and 3.0%p and 3.9%p in the control region, respectively. The number of dispensations per prescription of diabetic patient in the intervention region increased by approximately 4.61% by month compared to that in the control region. Conclusion: The intervention program encouraged older people with diabetes mellitus to receive continuous care for overcoming the rule of halves in the community. More research is needed to determine whether further improvement in the continuity of comprehensive care can prevent the progression of cardiovascular diseases.

• Journal of the Korea Society of Computer and Information
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• v.14 no.9
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• pp.11-19
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• 2009

A RAM-based Neural Net(RBNN) which has multi-discriminators is more effective than RBNN with a discriminator. Experience Sensitive Cumulative Neural Network and 3-D Neuro System(3DNS) that accumulate the features point improved the performance of BNN, which were enabled to train additional and repeated patterns and extract a generalized pattern. In recognition process of Neural Net with multi-discriminator, the selection of class was decided by the value of MRD which calculates the accumulated sum of each class. But they had a saturation problem of its memory cells caused by learning volume increment. Therefore, the decision of MRD has a low performance because recognition rate is decreased by saturation. In this paper, we propose the method which improve the MRD ability. The method consists of the optimum MRD and the matching ratio prototype to generalized image, the cumulative filter ratio, the gap of prototype response MRD. We experimented the performance using NIST database of NIST without preprocessor, and compared this model with 3DNS. The proposed MRD method has more performance of recognition rate and more stable system for distortion of input pattern than 3DNS.

• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.577-587
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• 2023

The utilization of crowdsourced spatial data has been actively researched; however, issues stemming from the uncertainty of data quality have been raised. In particular, when low-quality data is mixed into drone imagery datasets, it can degrade the quality of spatial information output. In order to address these problems, the study presents a methodology for automatically validating the geometric quality of crowdsourced imagery. Key quality factors such as spatial resolution, resolution variation, matching point reprojection error, and bundle adjustment results are utilized. To classify imagery suitable for spatial information generation, training and validation datasets are constructed, and machine learning is conducted using a radial basis function (RBF)-based support vector machine (SVM) model. The trained SVM model achieved a classification accuracy of 99.1%. To evaluate the effectiveness of the quality validation model, imagery sets before and after applying the model to drone imagery not used in training and validation are compared by generating orthoimages. The results confirm that the application of the quality validation model reduces various distortions that can be included in orthoimages and enhances object identifiability. The proposed quality validation methodology is expected to increase the utility of crowdsourced data in spatial information generation by automatically selecting high-quality data from the multitude of crowdsourced data with varying qualities.