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

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.438-443
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• 2003

In this paper, we propose a control algorithm for two-wheel mobile robot that can move the rider to his or her command and autonomously keep its balance. The control algorithm is based on a mixed $H_2/H_{\infty}$ control scheme. In this control problem the main issue is to move the rider while keeping its balance in the presence of disturbances and parameter uncertainties. The disturbance force caused by uneven road surfaces and the uncertainty due to different rider's heights are considered. To this end we first consider a state feedback controller as a basic framework. Secondly, we obtain the state feedback gain $K_2$ minimizing the $H_2$ norm and the state feedback gain $K_{\infty}$ minimizing the $H_{\infty}$ norm over the whole range of parameter uncertainty. Finally, we select mixed $H_2$/$H_{\infty}$ state feedback controller K as the geometric mean of $K_2$ and $K_{\infty}$. Simulation results show that the mixed $H_2/H_{\infty}$ state feedback controller combines the effects of the optimal $H_2$ state feedback controller and robust $H_{\infty}$ controller state feedback controller efficiently in the presence of disturbance and parameter uncertainty.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.93-101
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• 2020

Shipyards are potential environments for using IoT services, sensor networks, and delay tolerant networks. Simulations of those services and networks strongly rely on human mobility models. Results obtained with an unrealistic model may not reflect the true performance of applications, protocols, and algorithms in a shipyard. A lot of synthetic models for human movements have been studied but most of them are generic and focus on the daily movements of humans on city scales. Nevertheless, workers in shipyards have unique movement characteristics such as movement speed, pause time, and attractions places. For instance, workers usually move to some places, where they work, and rarely move to other places in the factory. Movement characteristics of workers not only depend on workers but also on tasks, which they do. For instance, workers, who paint ships, have similar movement speed and pause time. Hence, in this paper, human movements in shipyards are studied. We propose a new human mobility model called the human mobility mode in shipyards (MIS). In MIS, workers are classified into multiple types. Movement characteristics of a worker are similar to other workers in the same type. Based on the visiting probability, workers have some places, where they frequently visits, and some places, where they rarely visit. We analyze real mobility traces and studie to achieve human movement characteristics from real traces. The results show that MIS provides a well-match to the movement characteristic from real traces.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.440-447
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• 2018

Double parking is very common in a parking lot where there is not sufficient parking space. When we double-park a car, we leave transmission gear in neutral position and release the emergency brake so that the double-parked car can be moved just by pushing it. However, moving a double-parked car by pushing is very hard and dangerous especially for the old and the weak. So, we propose an omni-directional mobile robot for moving a double-parked car easily and safely. The developed omni-directional mobile robot moves a double-parked car by rotating a wheel of a double-parked car. It has two specially designed rollers to rotate a wheel of a double-parked car and is designed so that the height of the robot is very low to be able to enter beneath a double-parked car. It can move a double-parked car safely by detecting obstacles in the way with five ultrasonic sensors. We verified by several experiments that the developed omni-directional mobile robot can be used to move a double-parked car easily and safely.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.4
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• pp.941-951
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• 2016

Limitation of fossil energy from one side and the efficiency of the electrical engine from another side motivate the industrials to encourage people for utilizing electric vehicles (EVs). To decrease the cost of EVs, the size of battery should be reduced which causes an inconvenient frequent recharging. Wireless charging is a solution for charging of electric vehicles on the move, but frequent charging causes to disclose users' location information. In this paper, we first propose an infrastructure for wireless charging of electric vehicles, and then we explain security issues that can be stated in this condition.

• Journal of the Ergonomics Society of Korea
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• v.20 no.1
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• pp.15-29
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• 2001

This study was conducted to develop a prototype of adjustable desk and chair for students from elementary to high school. The development process started with identifying the problems of existing adjustable desks and chairs that are currently available in the market. The following fundamental design criteria were established and then applied to develop the prototype. The criterion of minimization of production cost yielding lower the market selling price was the most critically considered in view of the school furniture buyers' price-consciousness. Other design criteria used in this development were designing for stable and solid structure, requiring few motions and no tools to adjust, requiring the use of only one hand to adjust, unrestricting the adjustable interval, providing extra space for foot and knee area, reducing weight to move easily, and requiring not to move around for cleaning up floor. To evaluate the performance of the prototype, the adjustability of prototype was specifically compared with both dimensions suggested by KS G 2010(Korean Standards for desks and chairs for students) and current anthropometric dimension in terms of the flexible range of accommodation. Results of this study illustrate that the prototype developed in this study could be accommodated for the both dimensions. As a concluding mark, appropriate adjustable range for various grades and age groups were presented.

• Journal of Navigation and Port Research
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• v.39 no.5
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• pp.423-429
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• 2015

The expansion on the scale of international trade and rapid economic growth in Northeast Asia have caused intense competition among global companies for securing international logistics center in Northeast Asia. Analyzing location competitiveness for international logistics center in Northeast Asia, this paper aims to extract implications for enhancing locational competitiveness. Employing the relative importance among location selection factors extracted from AHP analysis in prior study, we evaluated the major five port-cities in Northeast Asia including Busan, Gwangyang, Shanghai, Qingdao and Tokyo. In the evaluations, Shanghai (3.926) ranked as the first, followed by Busan (3.859), Qingdao (3.555), Tokyo (3.013) and Gwangyang (2.915). Furthermore, the causal relationships between determinants for location choice decision (logistics factor, cost factor, market factor, service factor and environmental factor) and dependent variables (competitiveness of international logistics center, potentiality to growth, present intention to move into and future plan to move into) were analyzed to provide implications. Results provide useful insights for further improvements, and helps strategic agenda for future development of port-cities.

• Korean Institute of Interior Design Journal
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• v.19 no.2
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• pp.234-242
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• 2010

The twenty seven houses at Incheon city, were remodeled in 2009 for the physically handicapped people. This research had been done the analysis of the itemized questionnaire by the needs of the physically handicapped for their better living environment and suggested the following remodeling devices. First of all, there was the priority for the remodeling of their living facilities. According to their priority, they wanted to remodel their bathroom, kitchen & dining room, veranda, living room, and hall way. These were based on their needs of movement, personal hygiene, convenient closet, and cabinet usage. In particular, their demands were shown as followings. The wheelchair using handicapped people required safe doorknobs, unslippery floor materials, removal of step levels, and heights adjustable washing stand for their bathroom. They also requested washboard, non-threshold, and automatic door locks. Otherwise, the disabled in critical condition who could not move anything preferred the remodeling of inner structure of living spaces and automatic door system. The slight disabled and the families those who have the disabled demanded the remodeling of kitchen & dining room, and preferred the reorganization of closet, cabinets, floor tiles, and turncock. The remodeling of bedroom was mostly requested by the disabled women, people with the brain disorder, and disabled people in critical condition who could not move anything. They wanted the remote controlled lightings.

• Journal of the Korean Home Economics Association
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• v.38 no.9
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• pp.143-157
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• 2000

The purpose of this study was to show the possibility of labor mobility among married women by analysing some variables to have effects on their employment status and willingness to move in the labo market, namely, whether they would willingly enter into/come out the labor market. The personal collecting data were used and one discirminant function and two probit models were employed to analyse the efficients to the independent variables. The resets of this study were as follows. The very discriminant variables to have significant effects on the employment status of married women were the age of the youngest and the number of children. The willingness to enter into the labor market of unemployed married women was high in contrast as the willingness to keep the job was high among employed married women. The subjective perception on their own health, children related variables, and financial variable were very significant to predict the possiblities to move in the labor market among married women. It was remarkable that the psychological variables, which were related with the attitudes toward the occupation of house wife and employment of married women, were also important. These results showed that first of all, the decision of whether they enter into or come out in the labor market among married women is largely on the basis of the household situation not on the personal capacities of married women themselves.

• Journal of KSNVE
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• v.4 no.1
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• pp.83-88
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• 1994

In many circumstances, it is desired to move a mass from one position to another without inducing and vibration in the mass being moved. Two such problems are considered here : the motion of a mass initiated by another mass, nd the motion of a pendulum initiated by the specified motion of its support. In each case, it is dosired that the system start at rest and come to rest in the second position. A simple strategy for the specified motion is given here. The method is motivated by engine cam-follower design. The force required to move the system in question is determined as well as the maximum value of the force required(and the times at which these forces take place).