• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1577-1589
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• 2023

Recently, the necessity of predicting changes for monitoring ocean is widely recognized. In this study, we performed a time series prediction of remote-sensing reflectance (Rrs), which can indicate changes in the ocean, using Geostationary Ocean Color Imager (GOCI) data. Using GOCI-I data, we trained a multi-scale Convolutional Long-Short-Term-Memory (ConvLSTM) which is proposed in this study. Validation was conducted using GOCI-II data acquired at different periods from GOCI-I. We compared model performance with the existing ConvLSTM models. The results showed that the proposed model, which considers both spatial and temporal features, outperformed other models in predicting temporal trends of Rrs. We checked the temporal trends of Rrs learned by the model through long-term prediction results. Consequently, we anticipate that it would be available in periodic change detection.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.1-8
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• 2017

In this paper we present a spatial big data query processing system that can store spatial data in Hadoop and query the data with SQL-based query language. The system stores large-scale spatial data in HDFS-based storage system, and supports spatial queries expressed in SQL-based query language extended for spatial data processing. It supports standard spatial data types and functions defined in OGC simple feature model in the query language. This paper presents the development of core functions of the system including query language parsing, query validation, query planning, and connection with storage system. We compares the performance of the suggested system with an existing system, and our experiments show that the system shows about 58% performance improvement of query execution time over the existing system when executing region query for spatial data stored in Hadoop.

• Education of Primary School Mathematics
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• v.23 no.2
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• pp.63-72
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• 2020

The purpose of this study is to develop a mathematics self-efficacy test tool for elementary school students based on the sub-factors of mathematical self-efficacy derived from current studies. In this study, I verified the validity and reliability of the test tool by statistically evaluating the results of applying the test tool to the 3rd-6th grade students. In this study, Principal Component Analysis was performed on the tool for measuring the self efficacy of mathematics for elementary school students. For the validity test, the mathematics anxiety status of the participants was measured. The mathematics anxiety who were known to have a negative correlation with the mathematical self efficacy. The mathematics self efficacy tool developed in this study consists of 16 items with three subcategories: master experience, social persuasions, and emotional and physiological state. The mathematical self efficacy test tool developed in this study is expected to provide grounds for diagnosing the mathematics self-efficacy status of elementary school students and looking for ways to improve it.

• The Journal of the Korea Contents Association
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• v.19 no.2
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• pp.450-459
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• 2019

Under the new media environment this study is designed to investigate how the concept, 'self-efficacy' would be applied in an advertising context. The current study reviews consumer-controlled media environment, consumers' various attitude toward advertising and strategies for coping for advertising. In addition, how self-efficacy has been defined and applied in politics, education, and the Internet was discussed. From the advertising perspective it is interesting to examine how self-efficacy would be defined and applied in the consumers' attitude toward advertising. Lastly, this study will examine effects of self-efficacy on advertising research and advertising industry. For further study on self-efficacy much research needs to be conducted, focusing on conceptual and operational definition. Specifically, scale development and validation tests of 'self-efficacy' should be preceded.

• International Journal of Highway Engineering
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• v.2 no.1
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• pp.147-156
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• 2000

Compaction is known to critically affect pavement performance. Due to its importance, a theoretical modelling of compacted density in the term of number of roller coverages is attempted by assuming compaction process essentially identical to pavement rutting. Excellent data fittings by the developed equation may prove the validation of assumptions made as well as justification of its use. According to the derived equation, a plot of density difference with respect to number of roller coverages in the logarithmic scale Produces a linear relationship. However, this linearity is turned out to be deviated by cooling effect, change of amplitude and frequency. Investigation of these three factors proposes a new generalized compaction density equation, which shows a promising future. By applying this general formula, the equations for the number of roller coverages required and the final compaction density obtained for a particular compaction project is derived first time in compaction research.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.1
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• pp.66-72
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• 2007

an approach to air-vehicle design, an application of the radio-controlled model flight test techniques has been presented. The approach presented in this study is to validate the air-vehicle design configuration by analyzing the flight test results of scale model with dynamic similarities, and then to apply the analyzed results to the aerodynamic design process in early stage of the air-vehicle development. To develop practically applicable similarity laws for the subscale flying model design, the air-vehicle motions are decoupled into rotational motions for stability & control similarities and translational motions for flight performance similarities. Also, detail techniques for radio-controlled model flight test have been developed. Based on the results obtained from the radio-controlled flight test, the present approach for air-vehicle design has shown to be useful to validate the air-vehicle design configuration.

• Journal of the Korean association of regional geographers
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• v.5 no.2
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• pp.1-14
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• 1999

In the course of modernization and globalization, each region in Korea has experienced deep subordination to the center of Seoul and the increase of colonization possibility by world capital. In order to overcome the current situation, above all, the strategies should be developed focusing on daily life and life space. The basis for the development of strategies is the establishment of regional identity on life space. It is because of the reason that life space, or small-scale region has drawn wide attention in the research of geography in recent years. Especially, humanistic geography and new regional geography have developed the concerning theory and methodology, and kept going on the research of small-scale regions. Generally speaking, there have been quite large amount of theoretical discussions on small-scale region in recent years in the field of geography. Empirical researches focusing on a particular small-scale region, however, have been rarely made. It seems related to the deficiency of data materials and the obscurity of research framework of small-scale regional geography. A community paper must be very helpful for the geographic research on small-scale region. As community paper is published based on county('gun'), small or mid-size city('si'), or district of large city('gu'), it deals with small news and daily life information closely attached to the region. Accordingly, it functions as a medium of the formation of regional identity. It is also a valuable source material for the validation of regional identity and for the analysis of identity-shaping mechanism. The geographic interests in community paper, first of all, should be taken shape by the work on the geographical distribution and the periodic change of publication situation of community papers in Korea. Another research subject on community paper is the examination of characteristics of the region by analyzing the news and the advertisements. The news in community paper must be a valuable data source of regional studies in geography. Also, the regional identification process of community people through the community paper could be and should be explored, and how the regional centrality, or self-generation based on the identity is achieved will be an important subject.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.2
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• pp.227-238
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• 2006

Line density index(LDI) was developed to quantify a densely isothermal line rate as standard index in the ocean environment. Theoretical background on the LDI development process restricting index range 0 to 100 was described. And validation test was done for the LDI application condition that total line length is not greater than 1/10 of unit area. NOAA SST(Sea Surface Temperature) data were used for the experimental application of LDI in the South Sea of Korea. Using GIS, $0.1^{\circ}C$ isothermal lines were linearized as vector data form SST raster data, and unit area were built as polygon data. For the LDI calculation, spatial overlapping(line in polygon) was implemented. To analyze the effect of unit area size for the LDI distribution, two cases of unit area size were designed and descriptive statistics was calculated including performing normality test. The results showed no change of LDI's essential characteristics such as mean and normality except for the range of value, variance and standard deviation. Accordingly, it was found that complex structure of thermal front and even smaller scale of front width than unit area size could influence on the LDI distribution. Also, correlation analysis performed between LDI and difference of temperature(${\Delta}T^{\circ}C$), and horizontal thermal gradient(${\Delta}T^{\circ}C/km$) on the front was obtained from linear regression model. This obtained value was compared with the results from previous researches. Newly developed LDI can be used to compare the thermal front regions changing spatio-temporally in the ocean environment using absolute index value. It is considered to be significant to analyze the relationship between thermal front and marine environment or front and marine organisms in a quantitative approach described in this study.

• Steel and Composite Structures
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• v.35 no.6
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• pp.799-813
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• 2020

Fatigue cracks of rib-to-deck (RD) joints have been frequently observed in the orthotropic steel decks (OSD) using conventional U-ribs (CU). Thickened edge U-rib (TEU) is proposed to enhance the fatigue strength of RD joints, and its effectiveness has been proved through fatigue tests. In-depth full-scale tests are further carried out to investigate both the fatigue strength and fractography of RD joints. Based on the test result, the mean fatigue strength of TEU specimens is 21% and 17% higher than that of CU specimens in terms of nominal and hot spot stress, respectively. Meanwhile, the development of fatigue cracks has been measured using the strain gauges installed along the welded joint. It is found that such the crack remains almost in semi-elliptical shape during the initiation and propagation. For the further application of TEUs, the design curve under the specific survival rate is required for the RD joints using TEUs. Since the fatigue strength of welded joints is highly scattered, the design curves derived by using the limited test data only are not reliable enough to be used as the reference. On this ground, an experiment-numerical hybrid approach is employed. Basing on the fatigue test, a probabilistic assessment model has been established to predict the fatigue strength of RD joints. In the model, the randomness in material properties, initial flaws and local geometries has been taken into consideration. The multiple-site initiation and coalescence of fatigue cracks are also considered to improve the accuracy. Validation of the model has been rigorously conducted using the test data. By extending the validated model, large-scale databases of fatigue life could be generated in a short period. Through the regression analysis on the generated database, design curves of the RD joint have been derived under the 95% survival rate. As the result, FAT 85 and FAT 110 curves with the power index m of 2.89 are recommended in the fatigue evaluation on the RD joint using TEUs in terms of nominal stress and hot spot stress respectively. Meanwhile, FAT 70 and FAT 90 curves with m of 2.92 are suggested in the evaluation on the RD joint using CUs in terms of nominal stress and hot spot stress, respectively.

• The Korean Journal of Coaching Psychology
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• v.4 no.2
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• pp.1-26
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• 2020

The purpose of this study was to develop and validate the Psychological Difficulties Scale of Working Moms(PDSWM). In the first study, 69items and 17 factors of the inventory were obtained based on interview, open-ended questionnaires. In the second study, the on-line surveys from 306 working mom was carried to analyze factor structure of the PDSWM. The final result showed that the 12 factor model with 64 items was appropriate. The third study was collected from 638 working mom and in order to make certain the cross-validity of the inventory, the group was divided into two groups (each group with 319 employees). The results of exploratory factor analyses using data of group 1 showed that the 8 factor structure with 48 items was appropriate. Also the results of confirmatory factor analysis using data of group 2 showed that the 8 factor structure indicated a satisfactory fit. Final 8 factors were as follows: 1) Feeling Apologetic to family members 2) Discrimination at workplace 3) burnt-out: both body and mind 4) Unequal distribution of child-rearing and house chore labor 5) Conflict with the babysitter/grandparents 6) Limit in further strengthening work competency 7) Social prejudice 8) Difficulty being on time for work. The PDSWM was significantly correlated with various criteria such as organizational commitment, life satisfaction, and work engagement. Based on such findings, implications, limitations, and the suggestions for future study were discussed.