• Journal of the Korea Computer Graphics Society
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• v.28 no.3
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• pp.79-89
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• 2022

With the popularity and the advanced graphics hardware technology of mobile devices, various mobile applications that help children with physical activities have been studied. This paper presents SandUp, a mobile application that guides the play of building sand castles using artificial intelligence and augmented reality(AR) technology. In the process of building the sandcastle, children can interactively explore the target virtual sandcastle through the smartphone display using AR technology. In addition, to help children complete the sandcastle, SandUp informs the sand shape and task required step by step and provides visual and auditory feedback while recognizing progress in real-time using the phone's camera and deep learning classification. We prototyped our SandUp app using Flutter and TensorFlow Lite. To evaluate the usability and effectiveness of the proposed SandUp, we conducted a questionnaire survey on 50 adults and a user study on 20 children aged 4~7 years. The survey results showed that SandUp effectively helps build the sandcastle with proper interactive guidance. Based on the results from the user study on children and feedback from their parents, we also derived usability issues that can be further improved and suggested future research directions.

• Journal of the Korean Institute of Rural Architecture
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• v.24 no.4
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• pp.85-95
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• 2022

This study is about the story of 'Saemi', existing in the Sacheon Alluvial fan area. Saemi is a local word for Dumbeong, which is the traditional water irrigation facilities in this area that could be formed according to the geographical characteristics of a Alluvial fan site. In the meantime, although Saemi has been an important source of water, related research has been mainly done from an ecological point of view. Accordingly, the researcher paid attention to the functional aspects of Saemi itself, grasped its location, distribution status, and usage including the construction method, and considered its intrinsic value through classification and characteristic analysis of Saemi. As a result of five field surveys from September 2021 to October 2022, 129 Saemies remained in the Sacheon alluvial fan area. According to the structure and shape, Saemi could be divided into basic type, complex type, and buried type. The basic type was subdivided into bucket-type and stairs-type along with the complex type, and the buried type was subdivided into all buried-type and some buried-type. Saemies were mainly distributed at the distal end of the Sacheon alluvial fan site, individual Saemies were built on farmland, and common Saemies were usually built along roadsides adjacent to villages. The reason why the Saemies are concentrated at the distal end is the geographical characteristics of the alluvial fan where the water underflows. Saemi was an important multifunctional water supply source equivalent to the main water source for people at the distal end of the pond who did not receive a stable supply of water from the reservoir. Saemi was at the center of the underground water irrigation network agricultural system in the Sacheon alluvial fan area according to the principles of 'bbaeim(drop out)' and 'gaepim(pooling)' It has provided a foundation for establishing itself as an appropriate technology in this area. Such Saemi contributed to the rural landscape and agricultural biodiversity through its own system and served as a public interest function. It is necessary to know, conserve, manage, and continuously utilize the value of this Saemi as an agricultural heritage.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.461-466
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• 2024

Korean local governments operates the participatory budgeting system autonomously. This study is to classify these entities into clusters. Among the diverse machine learning methodologies(Neural Network, Rule Induction(CN2), KNN, Decision Tree, Random Forest, Gradient Boosting, SVM, Naïve Bayes), the Support Vector Machine technique emerged as the most efficacious in the analysis of 2022 Korean municipalities data. The first cluster C1 is characterized by minimal committee activity but a substantial allocation of participatory budgeting; another cluster C3 comprises cities that exhibit a passive stance. The majority of cities falls into the final cluster C2 which is noted for its proactive engagement in. Overall, most Korean local government operates the participatory busgeting system in good shape. Only a small number of cities is less active in this system. We anticipate that analyzing time-series data from the past decade in follow-up studies will further enhance the reliability of classifying local government types regarding participatory budgeting.

• Korean Journal of Radiology
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• v.22 no.8
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• pp.1323-1331
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• 2021

Objective: To identify the association between renal tumor complexity and pathologic renal sinus invasion (RSI) and evaluate the usefulness of computed tomography tumor features for predicting RSI in patients with renal cell carcinoma (RCC). Materials and Methods: This retrospective study included 276 consecutive patients who underwent radical nephrectomy for RCC with a size of ≤ 7 cm between January 2014 and October 2017. Tumor complexity and anatomical renal sinus involvement were evaluated using two standardized scoring systems: the radius (R), exophytic or endophytic (E), nearness to collecting system or sinus (N), anterior or posterior (A), and location relative to polar lines (RENAL) nephrometry and preoperative aspects and dimensions used for anatomical classification (PADUA) system. CT-based tumor features, including shape, enhancement pattern, margin at the interface of the renal sinus (smooth vs. non-smooth), and finger-like projection of the mass, were also assessed by two independent radiologists. Univariable and multivariable logistic regression analyses were performed to identify significant predictors of RSI. The positive predictive value, negative predictive value (NPV), accuracy of anatomical renal sinus involvement, and tumor features were evaluated. Results: Eighty-one of 276 patients (29.3%) demonstrated RSI. Among highly complex tumors (RENAL or PADUA score ≥ 10), the frequencies of RSI were 42.4% (39/92) and 38.0% (71/187) using RENAL and PADUA scores, respectively. Multivariable analysis showed that a non-smooth margin and the presence of a finger-like projection were significant predictors of RSI. Anatomical renal sinus involvement showed high NPVs (91.7% and 95.2%) but low accuracy (40.2% and 43.1%) for RSI, whereas the presence of a non-smooth margin or finger-like projection demonstrated comparably high NPVs (90.0% and 91.3% for both readers) and improved accuracy (67.0% and 73.9%, respectively). Conclusion: A non-smooth margin or the presence of a finger-like projection can be used as a preoperative CT-based tumor feature for predicting RSI in patients with RCC.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.4
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• pp.63-75
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• 2016

Aquaculture has historically delivered marine products because the country is surrounded by ocean on three sides. Surveys on production have been conducted recently to systematically manage aquaculture facilities. Based on survey results, pricing controls on marine products has been implemented to stabilize local fishery resources and to ensure minimum income for fishermen. Such surveys on aquaculture facilities depend on manual digitization of aerial photographs each year. These surveys that incorporate manual digitization using high-resolution aerial photographs can accurately evaluate aquaculture with the knowledge of experts, who are aware of each aquaculture facility's characteristics and deployment of those facilities. However, using aerial photographs has monetary and time limitations for monitoring aquaculture resources with different life cycles, and also requires a number of experts. Therefore, in this study, we investigated an automatic prototype system for detecting boundary information and monitoring aquaculture facilities based on satellite images. KOMPSAT-3 (13 Scene), a local high-resolution satellite provided the satellite imagery collected between October and April, a time period in which many aquaculture facilities were operating. The ANN classification method was used for automatic detecting such as cage, longline and buoy type. Furthermore, shape files were generated using a digitizing image processing method that incorporates polygon generation techniques. In this study, our newly developed prototype method detected aquaculture facilities at a rate of 93%. The suggested method overcomes the limits of existing monitoring method using aerial photographs, but also assists experts in detecting aquaculture facilities. Aquaculture facility detection systems must be developed in the future through application of image processing techniques and classification of aquaculture facilities. Such systems will assist in related decision-making through aquaculture facility monitoring.

• Journal of Radiation Protection and Research
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• v.26 no.2
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• pp.59-66
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• 2001

It is a hot issue to determine the spatial location and shape of tumor boundary in fractionated stereotactic radiotherapy (FSRT). We could get consecutive transaxial plane images from the phantom (paraffin) and 4 patients with brain tumor using helical computed tomography(HCT). K-means classification algorithm was adjusted to change raw data pixel value in CT images into classified average pixel value. The classified images consists of 5 regions that ate tumor region (TR), normal region (NR), combination region (CR), uncommitted region (UR) and artifact region (AR). The major concern was how to separate the normal region from tumor region in the combination area. Relative average deviation analysis was adjusted to alter average pixel values of 5 regions into 2 regions of normal and tumor region to define maximum point among average deviation pixel values. And then we drawn gross tumor volume (GTV) boundary by connecting maximum points in images using semi-automatic contour method by IDL(Interactive Data Language) program. The error limit of the ROI boundary in homogeneous phantom is estimated within ${\pm}1%$. In case of 4 patients, we could confirm that the tumor lesions described by physician and the lesions described automatically by the K-mean classification algorithm and relative average deviation analyses were similar. These methods can make uncertain boundary between normal and tumor region into clear boundary. Therefore it will be useful in the CT images-based treatment planning especially to use above procedure apply prescribed method when CT images intermittently fail to visualize tumor volume comparing to MRI images.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1194-1202
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• 2012

Remotely sensed satellite images can be applied to monitor and obtain land surface information on inaccessible areas. We classified paddy field area in North Korea based on on-screen digitization with visual interpretation using 291 RapidEye satellite images covering the whole country. Criteria for paddy field classification based on RapidEye imagery acquired at different time of rice growth period was defined. Darker colored fields with regular shape in the images with false color composite from early May to late June were detected as rice fields. From early July to late September, it was hard to discriminate rice canopy from other type of vegetation including upland crops, grass, and forest in the image. Regular form of readjusted rice field in the plains and uniform texture when compared with surrounding vegetation. Paddy fields classified from RapidEye imagery were mapped and the areas were calculated by administrative district, province or city. Sixty six percent of paddy fields ($3,521km^2$) were distributed in the west coastal regions including Pyeongannam-do, Pyeonganbuk-do, and Hwanghaenam-do. The paddy field areas classified from RapidEye images showed less than 1% of difference from the paddy field areas of North Korea reported by FAO/WFP (Food and Agriculture Organization/World Food Programme).

• KDI Journal of Economic Policy
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• v.12 no.4
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• pp.21-46
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• 1990

This paper, a sequel to Yoo and Lee (1990), attempts to investigate the interindustry determinants of technical efficiency in Korea's manufacturing industries, and also to conduct an exploratory analysis on the stability of technical efficiency over time. The hypotheses set forth in this paper are most found in the existing literature on technical efficiency. They are, however, revised and shed a new light upon, whenever possible, to accommodate any Korea-specific conditions. The set of regressors used in the cross-sectional analysis are chosen and the hypotheses are posed in such a way that our result can be made comparable to those of similar studies conducted for the U.S. and Japan by Caves and Barton (1990) and Uekusa and Torii (1987), respectively. It is interesting to observe a certain degree of similarity as well as differentiation between the cross-section evidence on Korea's manufacturing industries and that on the U.S. and Japanese industries. As for the similarities, we can find positive and significant effects on technical efficiency of relative size of production and the extent of specialization in production, and negative and significant effect of the variations in capital-labor ratio within industries. The curvature influence of concentration ratio on technical efficiency is also confirmed in the Korean case. There are differences, too. We cannot find any significant effects of capital vintage, R&D and foreign competition on technical efficiency, all of which were shown to be robust determinants of technical efficiency in the U.S. case. We note, however, that the variables measuring capital vintage effect, R&D and the degree of foreign competition in Korean markets are suspected to suffer from serious measurement errors incurred in data collection and/or conversion of industrial classification system into the KSIC (Korea Standard Industrial Classification) system. Thus, we are reluctant to accept the findings on the effects of these variables as definitive conclusions on Korea's industrial organization. Another finding that interests us is that the cross-industry evidence becomes consistently strong when we use the efficiency estimates based on gross output instead of value added, which provides us with an ex post empirical criterion to choose an output measure between the two in estimating the production frontier. We also conduct exploratory analyses on the stability of the estimates of technical efficiency in Korea's manufacturing industries. Though the method of testing stability employed in this paper is never a complete one, we cannot find strong evidence that our efficiency estimates are stable over time. The outcome is both surprising and disappointing. We can also show that the instability of technical efficiency over time is partly explained by the way we constructed our measures of technical efficiency. To the extent that our efficiency estimates depend on the shape of the empirical distribution of plants in the input-output space, any movements of the production frontier over time are not reflected in the estimates, and possibilities exist of associating a higher level of technical efficiency with a downward movement of the production frontier over time, and so on. Thus, we find that efficiency measures that take into account not only the distributional changes, but also the shifts of the production frontier over time, increase the extent of stability, and are more appropriate for use in a dynamic context. The remaining portion of the instability of technical efficiency over time is not explained satisfactorily in this paper, and future research should address this question.

• Korean Journal of Health Education and Promotion
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• v.6 no.2
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• pp.23-39
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• 1989

There have been a lot of considerable. discussion and debate surrounding the management model in the health insurance management system and opinions regarding the management operating cost. It is a well known fact that there have always been dissenting opinions and debates surrounding the issue. The management operating cost varies according to the scale of the management organization and component members characteristics of the insurance carrier. Therefore, it is necessary to examine and compare the management operating cost to the simulated management models developed to cover those eligible for the health insurance scheme in this country. Since the management operating cost can vary according to the different models of management, four alternative management models have been established based on the critical evaluation of existing theories concerned, as well as on the basis of the survey results and simulation attempts. The first alternative model is the Unique Insurance Carrier Model(Ⅰ) ; desigened to cover all of the people with no classification of insurance qualifications and finances from the source of contribution of the insured, nationwide. The second is the Management Model of Large-scale District Insurance Carrier(Ⅱ) ; this means the Korean society would be divided into 21 large districts; each having its own insurance carrier that would cover the people in that particular district with no classification of insurance qualifications arid finances as in Model I. The third is the Management Model of Insurance Carrier Divided by Area and Classified with Occupation if Largescale (Ⅲ) ; to serve the self-employed in the 21 districts divided as in Model Ⅱ. It would serve the employees and their dependents by separate insurance carriers in large-scale similar to the area of the district-scale for the self-employed, so that the insurance qualifications and finances would be classified with each of the insurance carriers: The last is the Management Model of the Multi - insurance Carrier (Ⅳ) based on the Si. Gun. Gu area which will cover their own self- employed people in the area with more than 150 additional insurance carriers covering the employees and their dependents. The manpower necessary to provide services to all of the people according to the four models is calculated through simulation trials. It indicates that the Management Model of Large-scale District Insurance Carrier requires the most manpower among the four alternative models. The unit management operating costs per the insured individuals and covered persons are leveled with several intervals based on the insurance recipients. in their characteristics. The interval levels derived from the regression analysis reveal that the larger the scale of the insurance carriers is in the number of those insured and covered. the more the unit management operating cost decreases. significantly. Moreover. the result of the quadratic functional formula also shows the U-shape significantly. The management operating costs derived from the simulated calculation. on the basis of the average salary and related cost per staff- member of the Health Insurance Societies for Occupational Labours and Korean Medical Insurance Corporation for the Official Servants and Private School Teachers in 1987 fiscal year. show that the Model of Multi-insurance Carrier warrants the highest management operating cost. Meanwhile the least expensive management operating cost is the Management Model of Unique Insurance Carrier. Insurance Carrier Divided by Area and Classified with Occupation in Large-scale. and Large-scale District Insurance Carrier. in order. Therefore. it is feasible to select the Unique Insurance Carrier Model among the four alternatives from the viewpoint of the management operating cost and in the sense of the flexibility in promoting the productivity of manpower in the human services field. However. the choice of the management model for health insurance systems and its application should be examined further utilizing the operation research analysis for such areas as the administrative efficiency and factors related to computer cost etc.

• Development and Reproduction
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• v.10 no.4
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• pp.227-238
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• 2006

Genomic DNAs(gDNAs) were isolated from the venus clam(Gomphina aequilatera) from Samcheok(venus clam from Samcheok; VCS) and Wonsan(venus clam from Wonsan; VCW) located in the East Sea of the Korean Peninsula. The amplified products were generated by agarose gel electrophoresis(AGE) with oligonucleotides primer, detected by staining with ethidium bromide and viewed by ultraviolet ray. The seven arbitrarily selected primers BION-21, BION-23, BION-25, BION-27, BION-29, BION-31 and BION-33 generated the shared loci, polymorphic, and specific loci, with the molecular sizes ranging from 150 bp to 2,400 bp. In this study, 147 polymorphic loci(147/954 loci, 15.41%) in VCS population and 274(274/996 loci, 27.51%) in VCW population were generated with seven primers. These results suggest the genetic variation in VCW population is higher than in VCS population. Especially, the 700 bp bands generated by the primer BION-21 were identified commonly in two Gomphina populations, which identified populations and/or species. This specific primer was found to be useful in the identification of individuals and/or population, resulting from the different DNA polymorphism among individuals/species/population. Two Gomphina populations between the individual SAMCHEOK no. 03 and WONSAN no. 22 showed the longest genetic distance(0.696) in comparison with other individuals used. The complete linkage cluster analysis indicating three genetic groupings and dendrogram revealed close relationships among individual identities within two geographical populations of venus clam(G. aequilatera) from the Samcheok and Wonsan. The intra-species classification and clustering analyses inferred from molecular markers supported the traditional taxonomy of the species based on morphological characters such as shell size, shape and color. Accordingly, as mentioned above, RAPD analysis showed that VCS population was more or less separated from VCW population.