• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.3
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• pp.18-29
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• 2022

Recently, cooperative intelligent transport systems (C-ITS) testbeds have been deployed in great numbers, and advanced autonomous driving research using V2X communication technology has been conducted actively worldwide. In particular, the broadcasting services in their beginning days, giving warning messages, basic safety messages, traffic information, etc., gradually developed into advanced network services, such as platooning, remote driving, and sensor sharing, that need to perform real-time. In addition, technologies improving these advanced network services' throughput and latency are being developed on many fronts to support these services. Notably, this research analyzed the network latency requirements of the advanced network services to develop a remote driving service for the droid type low-speed robot based on the 3GPP C-V2X communication technology. Subsequently, this remote driving service's performance was evaluated using system modeling (that included the operator behavior) and simulation. This evaluation showed that a respective core and access network latency of less than 30 ms was required to meet more than 90 % of the remote driving service's performance requirements under the given test conditions.

• Journal of Creative Information Culture
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• v.4 no.2
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• pp.95-101
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• 2018

As a result of introducing robot assisted learning which utilizes social robots or telepresence robots in language learning or special education, research on technology acceptance model for robot-assisted learning is also being conducted. The unified theory of acceptance and use of technology (UTAUT) model of intelligent robot has been studied, but of tele-operated robot is insufficient. The purpose of this paper is to estimate the UTAUT model by pre-service teachers who experienced telepresence robot-assisted learning that can be done in future school. It is found that the estimated UTAUT model consists of more concise factors than social robots, and the importance of perceived enjoyment is higher. In other words, the pre-service teachers showed significant acceptance of tele-operated robots with enhanced enjoyment composed of its mobility, communication, and touchable appearance of the face and body.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.931-941
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• 2020

There is a growing interest this paper for ocean sensing where autonomous vehicles can play an essential role in assisting engineers, researchers, and scientists with environmental monitoring and collecting oceanographic data. This study was conducted to develop a rigid sail for the autonomous sailing drone. Our study aims to numerically analyze the aerodynamic characteristics of curvy twin sail and compare it with wing sail. Because racing regulations limit the sail shape, only the two-dimensional geometry (2D) was open for an optimization. Therefore, the first objective was to identify the aerodynamic performance of such curvy twin sails. The secondary objective was to estimate the effect of the sail's spacing and shapes. A viscous Navier-Stokes flow solver was used for the numerical aerodynamic analysis. The 2D aerodynamic investigation is a preliminary evaluation. The results indicated that the curvy twin sail designs have improved lift, drag, and driving force coefficient compared to the wing sails. The spacing between the port and starboard sails of curvy twin sail was an important parameter. The spacing is 0.035 L, 0.07 L, and 0.14 L shows the lift coefficient reduction because of dramatically stall effect, while flow separation is improved with spacing is 0.21 L, 0.28 L, and 0.35 L. Significantly, the spacing 0.28 L shows the maximum high pressure at the lower area and the small low pressure area at leading edges. Therefore, the highest lift was generated.

• Journal of the Economic Geographical Society of Korea
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• v.24 no.4
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• pp.425-445
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• 2021

The purpose of this study is to present policy implications for future urban regeneration projects by deriving factors that affect residents' life satisfaction by region. To this end, a survey was conducted and multiple regression analysis was conducted using the Changsin/Sungin-dong, Haebangchon, and Garibong-dong regions where the general type of neighborhood regeneration project of Seoul was conducted. As a result of the analysis, it was found that life satisfaction increased when autonomy among the local governance factors in Changsin/Sungin-dong and autonomy and network in Garibong-dong increased. When examining the factors of regional regeneration capacity for each region, in terms of local identity, landscape characteristics in all three regions had a significant effect on the life satisfaction of residents. In the case of local communities, it was found that the satisfaction with life of residents increased when individual competence in Changsin/Sungin-dong and participation capacity and relationship competence in Garibong-dong increased. In terms of local assets, natural and social assets in all three regions had a significant effect on the life satisfaction of residents. Therefore, it is judged that the relationship between the influence of residents' life satisfaction in the general type of neighborhood regeneration project for neighborhood regeneration will be a meaningful data in promoting the urban regeneration project.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.05a
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• pp.173-176
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• 2009

심박동 변동에 반영되는 자율신경계 활동으로부터 정신적 부하 즉 스트레스 상태를 평가할 수 있다. 또한 일상생활 중에서 지속적인 심전도 모니터링인 가능하다면 심장에 부하를 줄 수 있는 운동 중에도 사전에 급작스러운 심장 이상 증세를 예상할 수 있다. 본 연구에서는 일상생활 속에서도 생체신호 측정이 가능한 무구속, 무자각, 무침습적인 심전도 측정 시스템을 개발하였다. 무선 통신을 사용하여 실시간으로 심장 활동 상태를 모니터링 할 수 있으며, 가슴에 부착이 가능한 패치 타입의 소형 전극 형태이다. 신뢰도 평가를 위하여 임상 심전도 신호와 본 전극으로 측정한 심전도 신호의 유사도를 평가하였으며 동잡음의 영향을 평가한 결과 $0{\sim}6m/h$로 걷는 경우, 심전도 파형이 안정적으로 나타나 일상생환에서의 활용가능성을 보여주었다. 동일한 피험자를 대상으로 HRV에 반영되는 스트레스의 영향을 평가하기 위하여 패치형 전극으로 심전도를 측정하여 불안, 스트레스 항목에 대한 설문지 평가, 스트레스 호르몬양을 측정하였다. 일상 상태와 스트레스 상태를 비교한 결과, 많은 파라미터에서 유의한 차이가 나타났다. 이러한 결과로부터 패치형 전극은 일상생활에서 건강 모니터링 시스템으로 활용도가 높을 것으로 기대된다.

• Journal of the Korean Data and Information Science Society
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• v.22 no.6
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• pp.1029-1040
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• 2011

In this paper we propose an intelligent navigation algorithm for real world problem which can build a map without localization. Proposed algorithm operates online and furthermore does not require many memories for applying real world problem. After applying proposed algorithm to toy and huge data set, it does not require to calculate a whole eigenspace and need less memory compared to existing algorithm. Thus we can obtain that proposed algorithm is suitable for real world mobile navigation algorithm.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.540-542
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• 2019

본 논문에서는 스마트블록 모듈을 활용한 스마트 모듈형 로봇 및 관련 콘텐츠인 자율주행로봇, 탐지 로봇 콘텐츠를 개발하였다. 스마트 모듈형 로봇의 H/W, S/W개발 및 스마트블록 모듈의 콘텐츠 활용방법 제안한다.

• 대한공업교육학회지
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• v.31 no.2
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• pp.332-349
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• 2006

The purpose of this study is to identify the relationship between the University students' learning styles in an e-learning according to the major field and learning styles in an e-learning according to the psychological types. The results of the research are as follows: First, The Major field made no difference to the learning styles in e-learning. E-learning styles of University student are as follows : the environment-dependent and self-directed learning style, positive and cooperative learning style, environment-independent and self-directed learning style. Second, In comparison with the boys and girl's the learning styles in e-learning, there were individual differences. But the environment-dependent and self-taught learning style was the highest learning style in Boys and Girl's but, especially there was more high in Girl's. Third, Amount to use internet made no difference to the learning styles in e-learning. The difference of learning styles in an e-learning environment according to Extraversion-Introversion, Sensing-Intuition, Thinking-Feeling among Psychological Types were statistically meaningless.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.11
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• pp.369-382
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• 2015

Energy aware server clusters aim to reduce power consumption at maximum while keeping QoS(quality of service) compared to energy non-aware server clusters. They adjust the power mode of each server in a fixed or variable time interval to activate only the minimum number of servers needed to handle current user requests. Previous studies on energy aware server cluster put efforts to reduce power consumption or heat dissipation, but they do not consider energy efficiency well. In this paper, we propose an energy efficient cluster management method to improve not only performance per watt but also QoS of the existing server power mode control method based on autonomous learning. Our proposed method is to adjust server power mode based on a hybrid approach of autonomous learning method with multi level thresholds and power consumption prediction method. Autonomous learning method with multi level thresholds is applied under normal load situation whereas power consumption prediction method is applied under abnormal load situation. The decision on whether current load is normal or abnormal depends on the ratio of the number of current user requests over the average number of user requests during recent past few minutes. Also, a dynamic shutdown method is additionally applied to shorten the time delay to make servers off. We performed experiments with a cluster of 16 servers using three different kinds of load patterns. The multi-threshold based learning method with prediction and dynamic shutdown shows the best result in terms of normalized QoS and performance per watt (valid responses). For banking load pattern, real load pattern, and virtual load pattern, the numbers of good response per watt in the proposed method increase by 1.66%, 2.9% and 3.84%, respectively, whereas QoS in the proposed method increase by 0.45%, 1.33% and 8.82%, respectively, compared to those in the existing autonomous learning method with single level threshold.

• Journal of Platform Technology
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• v.11 no.3
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• pp.24-31
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• 2023

Recently, interest in UAM (Urban Air Mobility, UAM), which can take off and land vertically in the operation of urban air transportation systems, has been increasing. Therefore, various start-up companies are developing related technologies as eco-friendly future transportation with advanced technology. However, studies on ways to increase safety in the operation of UAM are still insignificant. In particular, efforts are more urgent to improve the safety of risks generated in the process of attempting to land in the city center by UAM equipped with autonomous driving. Accordingly, this study proposes a plan to safely land by avoiding dangerous region that interfere when autonomous UAM attempts to land in the city center. To this end, first, the latitude and longitude coordinate values of dangerous objects observed by the sense of the UAM are calculated. Based on this, we proposed to convert the coordinates of the distorted planar image from the 3D image to latitude and longitude and then use the calculated latitude and longitude to compare the pre-learned feature descriptor with the HOG (Histogram of Oriented Gradients, HOG) feature descriptor to extract the dangerous Region. Although the dangerous region could not be completely extracted, generally satisfactory results were obtained. Accordingly, the proposed research method reduces the enormous cost of selecting a take-off and landing site for UAM equipped with autonomous driving technology and contribute to basic measures to reduce risk increase safety when attempting to land in complex environments such as urban areas.