• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.2
• /
• pp.138-142
• /
• 2014

This research presents an A* based algorithm which can be applied to Unmanned Ground Vehicle self-navigation in order to make the driving path smoother. Based on the grid map, A* algorithm generated the path by using straight lines. However, in this situation, the knee points, which are the connection points when vehicle changed orientation, are created. These points make Unmanned Ground Vehicle continuous navigation unsuitable. Therefore, in this paper, B-spline curve function is applied to transform the path transfer into curve type. And because the location of the control point has influenced the B-spline curve, the optimal control selection algorithm is proposed. Also, the optimal path tracking speed can be calculated through the curvature radius of the B-spline curve. Finally, based on this algorithm, a path created program is applied to the path results of the A* algorithm and this B-spline curve algorithm. After that, the final path results are compared through the simulation.

• Electronics and Telecommunications Trends
• /
• v.32 no.4
• /
• pp.67-77
• /
• 2017

최근 이슈가 되고 있는 자율주행차(Autonomous vehicle 또는 Self-driving car)를 실현하기 위해서는, 다양한 환경에서도 차량에 대한 끊김 없는 연결을 제공하는 커넥티드카(Connected car) 기술이 필수적이다. 현재 커넥티드카를 구현하기 위한 차량 네트워크(Vehicular network) 기술은 교통시스템 인프라 기반의 단일홉(Single-hop) 무선통신 기술이 주를 이루고 있다. 이러한 단일홉 통신은 커버리지가 교통시스템 인프라가 구축된 지역으로 제한된다. 따라서 차량 네트워크가 현재보다 더욱 넓은 지역을 커버하기 위해서는 차량 자체가 이동형 라우터 역할을 수행하여 차량 간의 전달을 통해 정보를 원거리로 전달할 수 있는 다중홉(Multi-hop) 통신 도입이 필요하다. 다중홉 차량 네트워크는 차량의 높은 동적 특성으로 인해 다수의 도전적인 기술적 이슈들을 가진다. 본고에서는 이러한 기술 이슈 중 차량 네트워크의 높은 이동성으로 발생할 수 있는 종단 노드 간 비연결성을 해결할 수 있는 기술인 지연감내형 차량 네트워킹(Delay-tolerant vehicular networking) 기술에 대한 주요 연구 동향을 살펴보고자 한다. 이를 위해 먼저 지연감내형 차량 네트워킹의 기술적 배경 및 주요 관련 기술들을 분석하고 이를 기반으로 향후 연구개발이 필요한 기술 이슈들을 정리한다.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1480-1484
• /
• 2004

In this paper, a self-propulsive and small concrete floor finishing trowel robot with twin trowels is proposed. Due to the small size and omni-directional moving capability, it is adequate for small space such as apartment. By adjusting the posture of trowels, it can move in any direction without wheels. We used cheap PIC processor for the cost saving design of the modules and adopted mode processors for easy operation of control stick. For the position control of the robot, we made a motion control algorithm appealing to the stepping motor driver module and the wireless communication module between the robot and PC (or control stick). In this paper, we discuss the control problem of the floor finishing robot in order to move to the right position. By comparing experimental result with simulation, we show the validity of the robot mechanism, sensors, and the control system.

• Journal of Korea Multimedia Society
• /
• v.23 no.9
• /
• pp.1219-1228
• /
• 2020

In this study, the factors affecting the acceptance intention for level 4-5 of autonomous vehicles were investigated by applying TAM(Technology Acceptance Model). To this end, 332 ordinary persons interested in autonomous vehicle and experienced in driving car were analyzed by using SEM(Structural Equation Modeling). The results showed that self-efficacy and personal innovation had a positive effect on perceived usefulness. On the other hand personal innovation has been shown to have a negative effect on perceived usefulness. Perceived ease of use has a positive effect on perceived usefulness, perceived ease of use and perceived usefulness has a positive effect on acceptance intention. Safety and Privacy has been shown to have a positive effect on trust, trust has a positive effect on acceptance intention. Lastly, autonomous vehicles have a higher impact on their 20s and 30s. The result of this study is expected to be a very useful basic research for the development of target autonomous vehicles, the selection of targets, the direction of corporate marketing strategies, and the preparation of government policies.

• Journal of Korean Academy of Nursing
• /
• v.35 no.6
• /
• pp.1014-1024
• /
• 2005

Purpose: This study was to exam me the effects of auricular acupuncture on insomnia in Korean elderly. Method: The study design was a triangulation study. Subjects were 40 elderly who were 65 years and over in Seoul, and 10 subjects for a qualitive study who were saturated with interviews and observation. The first auricular acupuncture was applied for three days, and this was applied to subjects on a 5 times series. The quantative data was analyzed by SPSS PC+ and the qualitive data was analyzed by driving of core meaning and abstract concepts using a semi-structural interview and observation. Result: I. The experimental group had higher significant sleep scores than that of the control group (t=32.739, p=.001). 2. The experimental group had higher significant self- satisfaction scores on sleep than that of the control group (t=30.049, p=.001). 3. In the qualitive study, insomnia characteristics before application of auricular acupressure therapy were confirmed by physical dysfunction, recall of past, and psychological dysfunction. Insomnia characteristics after application of auricular acupressure therapy were confirmed by recovery of physical dysfunction, improving recall of past, and recovery of psychological dysfunction. Conclusion: Auricular acupuncture was effective on insomnia in Korean elderly.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.12 no.3
• /
• pp.493-498
• /
• 2017

Recently, traffic data is analyzed for efficiency of bus operation, D2D(: Door to Door) service, and self-driving of public transportation. However, various studies have been carried out to predict the delay time of public transportation, especially buses, but the research to date has been insufficient due to limitations of simple analysis and data acquisition. In this study, delay time estimation is performed by collecting and processing data such as day of the week, weather, and time of day based on bus operation information. The proposed method in this paper can be applied to autonomous public transport and public traffic control system by improving the accuracy by adding variables in the future.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.3
• /
• pp.529-539
• /
• 1994

In laser heat treatment process of steels, the thin layer of substrate is rapidly heated to the austenitizing temperature and subsequently cooled at a very fast rate due to the self-quenching effect. Consequently, it is transformed to martensitic structure which has low magnetic permeability. This observation facilitates the use of a sensor measuring the change of electromagnetic field induced by the hardening layer. In this paper, the eddy-current electromagnetic field is analyzed by a finite element method. The purpose of this analysis is to investigate how the electrical impedance of the sensor's sensing coil varies with the change in permeability. To achieve this, a numerical model is formulated, taking into consideration the hardening depth, distance of the sensor from the hardened surface and the frequency driving the sensor. The results obtained by numerical simulation show that the eddy-current measurement method can feasibly be used to measure the changing hardening depth within the frequency range from 10 kHz to 50 kHz.

• Journal of Information Technology Applications and Management
• /
• v.16 no.2
• /
• pp.79-98
• /
• 2009

IPTV has risen as a new driving force amid concerns against the saturated internet market and gained enormous attention of both the government and industry as niche market. Especially, IPTV banking which is one of the major services, IPTV has risen up recently as another financial service channel. Prior to the expansion of the new technology, this study attempts to predict its success possibility. In order to grasp variables that would effect formation of user intention of potential adopters, and external variables that influence user intention of IPTV banking have been confirmed and studied empirically based on Technology Acceptance Model(TAM). As a result, it was validated that self?efficacy, facilitating condition, social influence, and perceived importance to TV banking needs are the influential variables. Therefore, one may able to find appropriate direction of marketing activities for effective expansion of IPTV banking service through this study. Also, considering the fact that the number of service users has absolute influence over profit determination in the IPTV banking service industry, the study about characteristics and intention of such potential adopters could certainly be significant.

• Journal of Korean Institute of Industrial Engineers
• /
• v.41 no.1
• /
• pp.50-58
• /
• 2015

The research on autonomous vehicle that expected to greatly reduce accidents by driver's mistakes is increasing in the development of technology. The purpose of this research is to identify the factor that affect trust in autonomous vehicles and analyze the requirements of the driver in autonomous vehicles environment. Therefore, in this study, we defined the information and functions provided by the autonomous vehicles through the investigation of the prior studies, conducted a questionnaire survey and focused group interview (FGI). The results show that competency, error management were important factors influencing trust in autonomous vehicles and identified that driver took safety related information as high priority in autonomous vehicle. Also, it was identified that driver prefer to perform the multimedia function in autonomous vehicle environment. The study is looking forward to be the reference data for design of advanced autonomous vehicle. It will contribute to the improvement of the convenience and satisfaction of the drivers.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2005.10a
• /
• pp.299-320
• /
• 2005

To rapidly respond to uncertainties in the business environment whilst remaining competitive, every organization needs to be able to successfully introduce and manage organizational change. Cognizant of the role of information systems (IS) as an enabler of organizational change, many organizations have paid attention to Enterprise Resource Planning (ERP) systems for successful organizational change primarily because of their change-driving forces across organizations. In this study, we focus attention on the role of readiness for change in the ERP systems adoption. Readiness for change described as views about the need for organizational change is posited to be and antecedent of two expectancies about the need for organizational change is posited to be an antecedent of two expectancies about the system. performance expectancy and effort expectancy, which lead to actual system use. In order to further establish th relevance of readiness for change as a determinant of two expectancies, computer self-efficacy is considered to be other key predictor as well. In addition, this study proposes that the personal characteristics of organizational commitment and perceived personal competence play roles of important determinants of readiness for change. Based on data gathered from the users of the ERP systems, structural equation analysis using LISREL provides significant support for the proposed relationships. Theoretical and practical implications are discussed along with limitations.