• Journal of the Korean Society for Precision Engineering
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• v.15 no.6
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• pp.107-115
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• 1998

A path planning using potential field method is very useful for the real-time navigation of mobile robots. However, the method needs high modeling cost to calculate the potential field because of complex preprocessing, and mobile robots may get stuck into local minima. In this paper, An efficient path planning algorithm for multiple mobile robots, based on the potential field method, was proposed. In the algorithm. the concepts of subgoals and obstacle priority were introduced. The subgoals can be used to escape local minima, or to design and change the paths of mobile robots in the work space. In obstacle priority, all the objects (obstacles and mobile robots) in the work space have their own priorities, and the object having lower priority should avoid the objects having higher priority than it has. In this paper, first, potential based path planning method was introduced, next an efficient collision-avoidance algorithm for multiple mobile robots, moving in the obstacle environment, was proposed by using subgoals and obstacle priority. Finally, the developed algorithm was demonstrated graphically to show the usefulness of the algorithm.

• The Journal of Korea Robotics Society
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• v.3 no.3
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• pp.186-193
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• 2008

We propose a novel real-time obstacle avoidance method for rescue robots. This method, named the ELA(Emergency Level Around), permits the detection of unknown obstacles and avoids collisions while simultaneously steering the mobile robot toward safe position. In the ELA, we consider two sensor modules, PSD(Position Sensitive Detector) infrared sensors taking charge of obstacle detection in short distance and LMS(Laser Measurement System) in long distance respectively. Hence if a robot recognizes an obstacle ahead by PSD infrared sensors first, and judges impossibility to overcome the obstacle based on driving mode decision process, the order of priority is transferred to LMS which collects data of radial distance centered on the robot to avoid the confronted obstacle. After gathering radial information, the ELA algorithm estimates emergency level around a robot and generates a polar histogram based on the emergency level to judge where the optimal free space is. Finally, steering angle is determined to guarantee rotation to randomly direction as well as robot width for safe avoidance. Simulation results from wandering in closed local area which includes various obstacles and different conditions demonstrate the power of the ELA.

• Journal of the Korean Institute of Educational Facilities
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• v.4 no.4
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• pp.17-28
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• 1997

The purpose of this study is to search for the effective way of development in managing Open Education Schools by analyzing obstacle reasons for school management of elementary school teachers on the basis of classroom site. This study researched 240 teachers and head teachers in three cities and counties of Chungbuk province through questionnaires which enquire obstacle reasons for Open Education. This research regarded 9 items including curriculum management and teaching method as main factors for consisting of Open Education School. And this analyzed the reactions from the percentages of interviewees. As a result of this analysis. obstacle reasons are as follows. 1. priority for academic background and the lack of school facilities and materials. 2. deficiency of teachers' belief in Open Education and unskilled practice. 3. closed situation in decision making and communication. 4. unreasonable management of finance and school facilities.

• International Journal of Advanced Culture Technology
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• v.9 no.4
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• pp.363-375
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• 2021

The purpose of this study is to analyze the safety of evacuation using the Pathfinder program for the alert at once, the priority alarm method, the priority alarm method for the four floors above, and the sequential priority alarm method, which is a modification of the priority alarm method specified in the tourist hotel building. Currently, in Korea's National Fire Safety Codes (NFSC), fire alarm methods are compulsorily applied differently depending on the number of floors and total floor area of a building. Although the growth rate is getting faster due to the diversification of building structures, it is still an obstacle to improving evacuation safety to comply with the standardized fire alarm method in NFSC. As a result of the experiment, the evacuation time was found to be faster with the priority alarm method for the four floors above than the priority alarm method applied to the specific firefighting object. Compared to the priority alarm method applied to the tourist hotel, which is a specific firefighting target with 5 or more floors and a total floor area of more than 3,000m2, the time was shortened by 3.7 seconds when measured by applying the priority alarm method for the four floors directly above. This indicates that it is necessary to take measures to select a fire alarm method suitable for the structure and environmental conditions of the building rather than applying the uniform NFSC regulations.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.230-233
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• 1987

This paper addresses the identification of various constraints in time-varying obstacle avoidance for mechanical manipulators. The manipulator constraints include the smoothness constraint and torque constraint, while the environmental constraints include a motion priority, a traveling time constraint, a path constraint, and a collision constraint. The inherent difficulties in combining these constraints are discussed with a suggestion for the purpose of time-varying obstacle avoidance.

• Journal of Korean society of Dental Hygiene
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• v.4 no.2
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• pp.237-253
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• 2004

This study was to find a patient's motive for receiving implant treatment by age and gender using a self-reporting questionnaire survey with adults(men & women) in Woolsan. The result was as follows: 1. As a result of questionnaire survey with 155 patients in total(86 men, 69 women), 24 of 86 men(27.9%) valued the natural mastication feature of dental implant most, that is as similar as natural teeth, while 18 of 69 women(26.1%) had the most priority over the longer life of implant than common dental prostheses. By age, those in their 20s and 30s had a preference to implant treatment because it does not need to pulling out teeth for prostheses, while those in their 40s and over had a priority to the natural mastication feature of implant that is similar as much as natural teeth. By dental treatment, all of respondents said that the natural mastication feature is the most important in getting dental implant. It was founded that whether one can taste food as it is or not is less important, regardless of age or gender. 2. The greatest obstacle to implant surgery was expensive medical fees, 88 of 155 respondents(56.8%), with a fear of surgery itself being the least obstacle. 3. 90.2% of the total respondents said that they will want to receive dental implant treatment if their economy allow.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.78-83
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• 2004

Currently used DLC(Direct Load Control) algorithm is only focused on ON/OFF load control not concerning about reliving participated customer's inconvenience and load priority. Therefore, that is a major obstacle to attract customer participating in demand response program. To overcome the above defects, the authors represent direct load control algorithm using priority based dynamic programming. the proposed algorithm is that participant customer send E-mail to DLC center about priority of load before executing DLC, then DLC algorithm decide which load to be OFF by using priority and off time constraint of the load. By using dynamic programming based on the order of priority for DLC algorithm it is possible to maximize participating customer's satisfaction and it will help to attract more customer's participating in demand response program.

• Journal of Internet Computing and Services
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• v.4 no.2
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• pp.1-9
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• 2003

Path restoration, which is needed to increase network survivability in MPLS networks, is a technology of supplying reliable service by delivering the traffics through restoring the paths when links or nodes of a working path are failed. In this paper, we propose a path restoration method using duplication of working paths for link failure as a method of restoring paths for the high priority traffics. The existing path restoration method transmits the traffics to the path restoration uniformly in regardless of the priority while link obstacle. It has a problem to take a long time to restore the connection of the high priority traffics. On the other hand, the suggested restoration method establishes the duplication path for the working path, which transmits the high priority traffics and transmit the traffics through the duplication path. It has a strong point to restore the connection quickly. Also, through simulation we analyze the performance of the restoration system using the duplication path and prove that the proposed restoration method is superior in performance to the existing restoration methods regarding to the high priority traffics.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.10
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• pp.3513-3533
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• 2021

This paper identifies challenging factors that hinder the successful settlement of the MyData industry, which is drawing global attention, and it analyzes the priority of solutions. To this end, a mixed-methodology including analytic network process technique was borrowed step-by-step to identify variables, analyze them, and provide interpretations. From the first step, the study found that the market aspect was the most important for the success of the K-MyData business, and the release of interesting representative services was found to be the easiest way to inspire market growth. From the second step, as a socio-cultural issue, the lack of consensus on data provisioning was found to present a major obstacle. To achieve consensus, it is very important for business participants to gain the trust of consumers. From the third step, it was found that the scope of data collection and responsibility for accidents needs to be clarified. Government and business-related persons must observe the principles of MyData while tackling these obstacles. It is also necessary for the government to be sensitive to changes in the environment as a focal actor. Doing so will lead to data industry activation and will help guarantee of rights of data subjects in a balanced manner. Finally, it is notable that technical barriers now have the lowest priority. Although technology is important, MyData business must also overcome market, socio-cultural, and institutional challenges. The study selected Korea as its research target, but it is expected to provide useful insights to other countries that are planning MyData business similar to Korea.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2337-2341
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• 2005

This paper presents the target detection method using Support Vector Machines(SVMs) and the navigation system using behavior-based fuzzy controller. SVM is a machine-learning method based on the principle of structural risk minimization, which performs well when applied to data outside the training set. We formulate detection of target objects as a supervised-learning problem and apply SVM to detect at each location in the image whether a target object is present or not. The behavior-based fuzzy controller is implemented as an individual priority behavior: the highest level behavior is target-seeking, the middle level behavior is obstacle-avoidance, the lowest level is an emergency behavior. We have implemented and tested the proposed method in our mobile robot "Pioneer2-AT". Comparing with a neural-network based detection method, a SVM illustrate the excellence of the proposed method.