• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.2 s.302
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• pp.1-10
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• 2005

This paper presents a technique for localization of a mobile robot using a single ultrasonic sensor. The mobile robot is designed for operating in a well-structured environment that can be represented by planes, edges, corners and cylinders in the view of structural features. In the case of ultrasonic sensors, these features have the range information in the form of the arc of a circle that is generally named as RCD (Region of Constant Depth). Localization is the continual provision of a knowledge of position which is deduced from it's a priori position estimation. The environment of a robot is modeled into a two dimensional grid map. we defines a physically-based sonar sensor model and employs an extended Kalman filter to estimate position of the robot. The performance and simplicity of the approach is demonstrated with the results produced by sets of experiments using a mobile robot.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.1
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• pp.67-75
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• 2010

This paper presents localization algorithm for mobile robot in outdoor environment. Outdoor environment includes the uncertainty on the ground. Magnetic sensor or IMU(Inertial Measurement Unit) has been used to estimate robot's heading angle. Two sensor is unavailable because mobile robot is electric car affected by magnetic field. Heading angle estimation algorithm for mobile robot is implemented using gyro sensor module consisting of 1-axis gyro sensors. Localization algorithm applied Extended Kalman filter that utilized GPS and encoder, gyro sensor module. Experiment results show that proposed localization algorithm improve considerably localization performance of mobile robots.

• Journal of Soil and Groundwater Environment
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• v.7 no.1
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• pp.3-14
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• 2002

We analyzed hydrologic time-series data obtained from a fractured aquifer in Wonju and a porous shallow aquifer in Uiwang area. Auto-correlation, spectral density, and cross-correlation functions were used for the analyses. Water level at a shallow well in Wonju was weakly auto-correlated and it was sensitive to direct infiltration from rainfall through soil zone while that at a well screened in the fractured zone showed a relative stability to an outer stress (rainfall), which was derived from a delayed transmission of recharge stress through a fracture network from a remote area. Characteristics of time-series data in Uiwang area were similar to those in the fractured zone in Wonju. This was caused by a regional recharge from a distant area rather than a direct infiltration. This study demonstrated a usefulness of time series analyses for identification of recharge mechanism.

• The Journal of the Korea Contents Association
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• v.19 no.10
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• pp.407-420
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• 2019

This study is an empirical study of 'the effect of Technological innovation through environmental factors of an enterprise on the implementation of a Smart Factory'. The purpose of the research is to improve the utilization and effectiveness of the Smart Factory by considering and implementing factors that will be promoted in an internal environment or focus when building. The research method was statistical analysis with SMART PLS by surveying the relevant personnel of the company that implemented the Smart Factory. The results of the study showed that internal organizational factors and self-efficacy have a positive effect on technological innovation, and technology innovation has a positive effect on the key factors of smart factory implementation. And the absorbing capacity, which is a moderating variable, has a positive effect in part on the key factors of smart factory implementation by interacting with technological innovation factors. This study can be used by companies that want to implement a smart factory, and it has the significance of laying the theoretical foundation for research on smart factory implementation through empirical analysis.

• Journal of Korean Society of Disaster and Security
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• v.16 no.1
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• pp.37-48
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• 2023

The possibility of a super-large disaster is increasing due to changes in national territory, urban space and social environment, extreme weather conditions due to climate change, and paralysis of national infrastructure due to natural disasters. In this study, in order to support the systematic establishment of national territorial disaster prevention strategies for future disasters, alternatives to intelligent national territorial disaster prevention policies for future disasters were considered. Changes in the national environment related to future disasters, domestic and foreign prior studies and policy trends related to national disaster prevention, and studies related to the national disaster management system were investigated, and institutional and technical policy alternatives were derived. As a policy alternative, it was suggested that the creation of a self-adapting national territory for future disasters should be systematized and continuously supported through a technically intelligent decision-making support system.

• Knowledge Management Research
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• v.24 no.1
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• pp.223-243
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• 2023

RPA is implemented through management policy and enforced in mandatory environments to enhance performance and efficiency in various fields. However, the success of RPA implementation depends on the level of active engagement from organization members, even in a mandatory setting. This study identifies perceived ease of use, usefulness, accountability, perceived risk, and self-efficacy as variables that influence conative use behavior, which consists of reflective secondary factors such as immersion, reinvention, and learning. Data was collected from 207 office workers in various industries who have experience with RPA to test the proposed research model. The structural equation was verified using SPSS 20.0 and SmartPLS 4.0, and the analysis showed that all the proposed variables had a significant impact on conative use behavior. Our research findings provide theoretical and practical implications in knowledge management, enabling companies that implement RPA to recognize and address factors that encourage their members to actively use RPA.

• Journal of The Korean Association For Science Education
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• v.26 no.2
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• pp.232-238
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• 2006

This study examined how motivational climate, achievement goals, and learning strategies jointly contributed to science achievement through path analysis of 260 middle school students. The results showed that only deep learning strategy had a significant direct effect on science achievement. The promotion of learning by science teachers and the pursuit of progress by peers had the mediational pathways linking task goal and deep learning strategy on science achievement. The pursuit of progress and the promotion of the comparison by peers influenced science achievement via deep learning strategy. The promotion of the comparison by peers also influenced deep learning strategy via performance-goal, which in turn influenced science achievement. These results indicated that the learning strategies had a direct effect and motivational climate or achievement goals had an indirect effect on science achievement. Our findings lead us to expect that the effective instructional method to improve students' science achievement is the one that impact both cognitive and motivational functioning.

• Environmental and Resource Economics Review
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• v.33 no.2
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• pp.135-157
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• 2024

In this study, we analyzed the changes in copper consumption according to copper price fluctuations and identified the domestic copper price elasticity. A total of 408 time series data from January 1989 to December 2022 were analyzed using the vector autoregressive (VAR) model with net import volume, price, and production index as variables. In addition, to identify changes in the correlation between variables over time, the dynamic relationship between variables was identified using the time-varying vector autoregressive (TV-VAR) model. As a result of the analysis, it was confirmed that the negative price elasticity for copper is -0.1835. In addition, the interquartile range was -0.3130 ~ 0.0886, with no consistent trend over time, but mainly negative elasticity. This study can be used to quantify the expected impact of various policy proposals and changes related to minerals.

• Journal of Agricultural Extension & Community Development
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• v.31 no.2
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• pp.41-56
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• 2024

This study aims to examine the causal relationshps between self-efficacy and job satisfaction of young farmers by verifying the mediating effect of self-efficacy in the relationship between job ability and job satisfaction of young farmers, and to improve the job ability necessary for agriculture, and to provide implications for the development and operation of curriculum that meets the needs of farmers. To this end, an online survey was conducted on 300 young farmers under the age of 40 among 4-H members in Korea from June 17 to 28, 2022. The results of the analysis to find out the mediating effect of self-efficacy in the relationship between job ability and job satisfaction of young farmers are as follows. First, it was verified that self-efficacy plays a partial mediating role in affecting job satisfaction by verifying whether the job ability of young farmers mediates self-efficacy in the relationship between job satisfaction and job satisfaction. It can be said that the higher the job ability, the more positive the job satisfaction and the more positive the self-efficacy, which ultimately has a positive effect on job satisfaction. Second, as a result of verifying whether self-efficacy is mediated in the relationship between job satisfaction and job satisfaction by sub-factors of job competency in detail, self-efficacy plays a partial mediating role between agricultural production ability, agricultural machine management ability, and job satisfaction, and agricultural management ability and agricultural information utilization ability do not have a direct significant effect on job satisfaction.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.298-298
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• 2021

본 연구에서는 국내 6개 지역 서울, 강릉, 대전, 광주, 부산, 제주의 30년 치 시강우 자료에 해석적 확률모형(Analytical Probabilistic Models) 방법을 적용하여 도시 홍수 저감을 목적으로 하는 저류시설 설계를 위한 유출량 예측 정도를 지역별로 비교하고자 하였다. 강우 사상 분포의 해석적 확률모형을 적용하기 위해 무강우 시간을 결정하여 독립 호우를 결정하는데, 자기상관계수와 변동계수를 활용한 무강우 지속시간의 산정(IETD, Interevent Time Definition) 방법을 사용하였다. 해석적 확률모형인 유출량의 확률밀도함수(PDF, Probability Density Function)를 유도하기 위해서 불투수 지역과 투수 지역의 영향을 고려하여 유출계수를 적용하는 강우-유출 관계를 가지고 유출량을 정의하였다. 강우량, 강우 지속시간, 무강우시간과 같은 강우특성은 1변수 지수함수의 PDF를 따른다고 가정하였다. 확률모형 방법의 적합성을 판단하기 위해 결정된 IETD에 따라 각 지역별로 실제 강우 사상을 해석적 모델과 연속모의실험인 SWWM(Storm Water Management Model)에 적용하여 불투수율에 따른 유출량을 산정하였다. 각 방식으로 얻은 유출량 결과는 모든 지역에서 매우 유사하게 나타났고 결론적으로 우리나라에서 도시 홍수 저감을 위한 저류시설의 계획과 설계에 확률모형 방법이 적용 가능하다는 것을 확인할 수 있었다.