• Journal of the Economic Geographical Society of Korea
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• v.23 no.1
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• pp.1-17
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• 2020

The study aims to identify economic interdependencies between regions and define functional economic areas of Korea by analyzing inter-firm transaction networks. Previous research has relied on pre-given administrative boundaries or cultural homogeneity and used data such as commuting, population movement, and cargo flows which could not fully explain economic activities. To overcome the limitations, this study applies a community detection method to inter-firm transaction networks derived from the CRETOP+ database of Korean corporate data. The novel dataset and the network analysis enables us to identify Korea's functional economic areas based on actual inter-firm linkages. The result shows that there are six to seven economic blocs in the networks as of 2018. In particular, one huge economic bloc is formed integrating the Seoul metropolitan area, Chungcheong, and Gangwon provinces. Meanwhile, North Jeolla and South Jeolla provinces form two economic blocs separately rather than being tied up in one bloc due to the low frequency of transactions between each other. The two big economic blocs of Daegu-Gyeongbuk and Busan-Gyeongnam exist, and interestingly, Ulsan, Gyeongju, and Pohang form a separate middle-sized bloc across the administrative boundaries. The results reveal that the future balanced national development policies should be implemented based on functional economic areas derived from empirical data.

• Journal of Digital Convergence
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• v.14 no.11
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• pp.275-281
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• 2016

In modern society, which boomed it became easier to obtain the necessary information to the emergence of a variety of smart devices. Due to this, the frequency of using the content based on the Web is growing rapidly. In addition, companies are turning into a production and modify the content using the CMS under the web-based. It can be a very important part to provide users with the content. Currently web services are designing a UI to the device and provided. To improve the ease of use, they are enhancing services only by survey and analysis of the patterns of all users. Most are designed without considering the UX only in the technical aspects. In this paper, to break the limits that apply to all users of the Web service pattern analysis, we propose a visualization system via the animation based on the individual user's movement patterns and usage patterns. Through this convergence is expected to be able to transform the web from the central manager to the user UX and the planning aspects researchers.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.1
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• pp.47-57
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• 2015

Along with climate change, the occurrence and severity of natural disasters have been increased globally. In particular, the increase of localized heavy rainfalls have caused severe flood damage. Thus, it is needed to consider climate change into the estimation of design flood, a principal design factor. The main objective of this study was to estimate design floods for an agricultural reservoir watershed based on the RCP (Representative Concentration Pathways) scenarios. Gyeryong Reservoir located in the Geum River watershed was selected as the study area. Precipitation data of the past 30 years (1981~2010; 1995s) were collected from the Daejeon meteorological station. Future precipitation data based on RCP2.6, 4.5, 6.0, 8.5 scenarios were also obtained and corrected their bias using the quantile mapping method. Probability rainfalls of 200-year frequency and PMPs were calculated for three different future spans, i.e. 2011~2040; 2025s, 2041~2070; 2055s, 2071~2100; 2085s. Design floods for different probability rainfalls were calculated using HEC-HMS. As the result, future probability rainfalls increased by 9.5 %, 7.8 % and 22.0 %, also design floods increased by 20.7 %, 5.0 % and 26.9 %, respectively, as compared to the past 1995s and tend to increase over those of 1995s. RCP4.5 scenario, especially, resulted in the greatest increase in design floods, 37.3 %, 36.5 % and 47.1 %, respectively, as compared to the past 1995s. The study findings are expected to be used as a basis to reduce damage caused by climate change and to establish adaptation policies in the future.

• Ecology and Resilient Infrastructure
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• v.2 no.2
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• pp.128-136
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• 2015

River areas include channels, floodplains and all the areas affected by physical and ecological processes in river systems. It is noticeably different from present riparian zone which is bounded by dykes. In this study, two methods for delineation of a floodplain are proposed, which are used for evaluation of the function of a river. One of them is a geomorphology-based technique and the other is hydrology-based inundation analysis. For the Mankyung River, these two methods are applied to delineate the floodplain area. Areas delineated with both methods are mutually compared. The results show that the geomorphology-based method is suitable for the delineation of a valley bottom, including the floodplain in a broader sense, which is unlike an inundated area reflecting contemporary hydrologic conditions. Compared with other flood frequency areas, a 100-year flood inundation area was found reasonable to represent the spatial extent of a floodplain without regard to the longitudinal location along a river. However, it is necessary in certain rivers reach where the division of a channel exists to compare a geomorphological analysis on a valley bottom with an inundation area of different frequencies.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.1
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• pp.120-130
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• 2012

As long span and complex bridges are constructed often recently, safety estimation became a big issue. Various types of measuring instruments are installed in case of long span bridge. New wireless technologies for long span bridges such as sending information through a gateway at the field or sending it through cables by signal processing the sensing data are applied these days. However, The case of occurred accidents related to bridge in the world have been reported that serious accidents occur due to lack of real-time proactive, intelligent action based on recognition accidents. To solve this problem in this study, the idea of "communication among things", which is the basic method of RFID/USN technology, is applied to the bridge monitoring system. A sensor node module for USN based intelligent bridge system in which sensor are utilized on the bridge and communicates interactively to prevent accidents when it captures the alert signals and urgent events, sends RF wireless signal to the nearest traffic signal to block the traffic and prevent massive accidents, is designed and tested by performing TinyOS based middleware design and sensor test free Space trans-receiving distance.

• Journal of KIISE:Databases
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• v.33 no.1
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• pp.86-101
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• 2006

The bandwidth of channel and the power of the mobile devices are limited on a wireless environment. In this case, data broadcast has become an excellent technique for efficient data dissemination. A significant amount of researches have been done on generating an efficient broadcast program of a set of data items with different access frequencies over multiple wireless broadcast channels as well as single wireless broadcast channel. In this paper, an efficient data allocation method over multiple wireless broadcasting channels is explored. In the traditional approaches, a set of data items are partitioned into a number of channel based on their access probabilities. However, these approaches ignore a variation of access probabilities of data items allocated in each channel. In practice, it is difficult to have many broadcast channels and thus each channel need to broadcast many data items. Therefore, if a set of data items broadcast in each channel have different repetition frequencies based on their access frequencies, it will give much better performance than the traditional approaches. In this paper, we propose an adaptive data allocation technique based on data access probabilities over multiple broadcast channels. Our proposed technique allows the adaptation of repetition frequency of each data item within each channel by taking its access probabilities into at count.

• The Journal of Korean society of community based occupational therapy
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• v.4 no.2
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• pp.23-30
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• 2014

Objective : The purpose of this study is to investigate the awareness and interest rate of occupational therapy in Korea, and to establish basic data for further development of occupational therapy through the results. Methods : This survey was conducted between October 1th and December 31st 2013 and 308 questionnaires were collected from university student and public. The questionnaires of 308 respondents were analyzed through Cosstabs, Descriptive statistics, Frequency study and t-test, ANOVA analysis using SPSS ver. 18.0. Results : There was a significant difference in the awareness rate of occupational therapy by age and occupation (p<.01). People who were knowledgeable about occupational therapy had a friend or relative related to occupational therapy(33.5%), or were informed through media(37.1%). Positive responses regarding whether responders wanted to find more about occupational therapy were high(53%), and publicity(63.5%) turned out to be the most effective method for advancement. Conclusion : Although there is a lack of public awareness on occupational therapy, high percentage of responders showed positive responses in receiving occupational therapy when they get an injury in the future, and furthermore, learn more about occupational therapy. Based on this result, it is clear that high percentage of people were showing interest to occupational therapy. It could be conjectured that active publicity through internet or media may be effective.

• Journal of Nutrition and Health
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• v.54 no.3
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• pp.247-261
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• 2021

Purpose: This study was conducted to identify the association between insulin resistance and the major dietary patterns of Korean adults. Methods: This study used data from the 2015 Korea National Health and Nutrition Examination Survey. The subjects were 2,276 adults aged 19 to 64 years old. Based on the food frequency questionnaire data, 112 food items were reclassified into 30 food groups. The principal component analysis method was applied to identify major dietary patterns. We used homeostatic model assessment of insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI) value as indicators of insulin resistance. The association between major dietary patterns and insulin resistance was investigated using logistic regression analysis. Results: Three major dietary patterns were identified and assigned descriptive names based on the food items with high loadings: 'healthy Korean meal pattern', 'western meal pattern', and 'white rice, alcohol, meat pattern'. As the 'white rice, alcohol, meat pattern' score increased, significant increasing trends for fasting glucose concentration and HOMA-IR and a significant decreasing trend for QUICKI were observed after adjusting for age and sex. The odds ratio of insulin resistance according to the 'healthy Korean meal pattern' and the 'western meal pattern' were not statistically significant. the 'white rice, alcohol, meat pattern' showed a significant positive association with the risk of insulin resistance after adjusting for covariates. Conclusion: These results suggest that the 'white rice, alcohol, meat pattern' is positively associated with the risk of insulin resistance. The white rice, alcohol, meat pattern was related to the high consumption of alcohol together with rice or meat. This pattern was also associated with the high intake of sodium and low intakes of vitamin C, calcium, potassium, and dietary fiber. To confirm the association, further longitudinal studies are required.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.839-850
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• 2018

The flood damage in urban areas due to torrential rain is increasing with urbanization. For this reason, accurate and rapid flooding forecasting and expected inundation maps are needed. Predicting the extent of flooding for certain rainfalls is a very important issue in preparing flood in advance. Recently, government agencies are trying to provide expected inundation maps to the public. However, there is a lack of quantifying the extent of inundation caused by a particular rainfall scenario and the real-time prediction method for flood extent within a short time. Therefore the real-time prediction of flood extent is needed based on rainfall-runoff-inundation analysis. One/two dimensional model are continued to analyize drainage network, manhole overflow and inundation propagation by rainfall condition. By applying the various rainfall scenarios considering rainfall duration/distribution and return periods, the inundation volume and depth can be estimated and stored on a database. The Rainfall-Duration-Flooding Quantity (RDF) relationship curve based on the hydraulic analysis results and the Self-Organizing Map (SOM) that conducts unsupervised learning are applied to predict flooded area with particular rainfall condition. The validity of the proposed methodology was examined by comparing the results of the expected flood map with the 2-dimensional hydraulic model. Based on the result of the study, it is judged that this methodology will be useful to provide an unknown flood map according to medium-sized rainfall or frequency scenario. Furthermore, it will be used as a fundamental data for flood forecast by establishing the RDF curve which the relationship of rainfall-outflow-flood is considered and the database of expected inundation maps.

• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1362-1369
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• 2018

A method aimed at improving the beam-wave interaction efficiency by changing the coupling slot configuration has been proposed in the study of extended interaction oscillators (EIOs). The dispersion characteristics, coupling coefficient and interaction impedance of the high-frequency structure based on different types of coupling slots have been investigated. Four types of coupled cavity structures with different layouts of the coupling slots have been compared to improve the beam-wave interaction efficiency, so as to analyze the beam-wave interaction and practical applications. In order to determine the improvement of the coupling slot to a coupled cavity circuit in an EIO, we designed four nine-gap EIOs based on the coupled cavity structure with different coupling slot configurations. With different operating frequencies and voltages takes into consideration, beam voltages from 27 to 33 kV have been simulated to achieve the best beam-wave interaction efficiency so that the EIOs are able to work in the $2{\pi}$ mode. The influence of the Rb and the ds on the output power is also taken into consideration. The Rb is the radius of the electron beam, and the ds is the width of the coupling slot. The simulation results indicate that a single-slot-type EIO has the best beam-wave interaction efficiency. Its maximum output power is 2.8 kW and the efficiency is 18% when the operating voltage is 31 kV and electric current is 0.5 A. The output powers of these four EIOs that were designed for comparison are not less than 1.7 kW. The improved coupling-slot configurations enables the extended interaction oscillator to meet the different engineering requirements better.