• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.825-836
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• 2019

One of the most challenging safety precautions for workers in dynamic, radioactive environments is avoiding radiation sources and sustaining low exposure. This paper presents a sampling-based algorithm, DL-RRT*, for minimum dose walk-path re-planning in radioactive environments, expedient for occupational workers in nuclear facilities to avoid unnecessary radiation exposure. The method combines the principle of random tree star ($RRT^*$) and $D^*$ Lite, and uses the expansion strength of grid search strategy from $D^*$ Lite to quickly find a high-quality initial path to accelerate convergence rate in $RRT^*$. The algorithm inherits probabilistic completeness and asymptotic optimality from $RRT^*$ to refine the existing paths continually by sampling the search-graph obtained from the grid search process. It can not only be applied to continuous cost spaces, but also make full use of the last planning information to avoid global re-planning, so as to improve the efficiency of path planning in frequently changing environments. The effectiveness and superiority of the proposed method was verified by simulating radiation field under varying obstacles and radioactive environments, and the results were compared with $RRT^*$ algorithm output.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.6
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• pp.689-696
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• 2009

In this paper, a new user interface for unmanned combat vehicle(UCV) is developed based on the mission planning and global path planning. In order to complete a tactical mission given to an UCV, it is essential to design an effective interface scheme between human and UCV considering changing combat environment and characteristics of the mission. The user interface is mainly composed of two parts, mission planning and global path planning, since they are important factors to accomplish combat missions. First of all, mission types of UCV are identified. Based on mission types, the concept of mission planning for UCVs is presented. Then a new method for global path planning is devised. It is capable of dealing with multiple grid maps to consider various combat factors so that paths suitable for the mission be generated. By combining these two, a user interface method is suggested. It is partially implemented in the Dog-horse Robot of ADD and its effectiveness is verified.

• Journal of information and communication convergence engineering
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• v.12 no.2
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• pp.116-121
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• 2014

This paper discusses computer-generated heuristics for motion planning. Planning with many degrees of freedom is a challenging task, because the complexity of most planning algorithms grows exponentially with the number of dimensions of the problem. A well-designed heuristic may greatly improve the performance of a planning algorithm in terms of the computation time. However, in recent years, with increasingly challenging high-dimensional planning problems, the design of good heuristics has itself become a complicated task. In this paper, we present an approach to algorithmically develop a heuristic for motion planning, which increases the efficiency of a planner in similar environments. To implement the idea, we generalize modern motion planning algorithms to an extent, where a heuristic is represented as a set of random variables. Distributions of the variables are then analyzed with computer learning methods. The analysis results are then utilized to generate a heuristic. During the experiments, the proposed approach is applied to several planning tasks with different algorithms and is shown to improve performance.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.6
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• pp.803-812
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• 2017

This paper proposes a local path planning method for stable autonomous driving in rough terrain. There are various path planning techniques such as candidate paths, star algorithm, and Rapidly-exploring Random Tree algorithms. However, such existing path planning has limitations to reflecting the stability of unmanned ground vehicles. This paper suggest a path planning algorithm that considering the stability of unmanned ground vehicles. The algorithm is based on the genetic algorithm and assumes to have probability based obstacle map and elevation map. The simulation result show that the proposed algorithm can be used for real-time local path planning in rough terrain.

• Journal of Families and Better Life
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• v.26 no.1
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• pp.149-163
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• 2008

This study examined the expectations and attitudes toward retirement, and financial planning for retirement among paid workers aged 20s and 30s. It compared paid workers' socio-economic, and retirement-related characteristics between those who had retirement planning and those who did not, and identified factors important to retirement planning decision. Data for this study were from a questionnaire completed by paid workers in age 20s and 30s (n=227), and were analyzed by t-tests, chi-square tests, and a logistic regression model. The findings of this study were as follows: First, the paid workers' expected retirement age was 56, and their ideal age for retirement was about 60. More than 85% of workers agreed that the retirement planning should begin before age 40, but just 51 % of the workers had retirement planning. Second, the workers aged 30s, married, and those who had higher incomes and home ownership were more likely to prepare financially for their retirement. Third, as their expected retirement age increased, the probability of decision to retirement planning increased. Those who expected that the economic status of retirees' living would be same as their current economic status were more likely to have retirement planning. The positive attitudes toward retirement had significant effect on the decision to have retirement planning.

• Korean Journal of Computational Design and Engineering
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• v.21 no.2
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• pp.196-203
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• 2016

In this paper, we propose a virtual surgical planning system specialized to mandible reconstruction surgery. Mandible reconstruction surgery is one of the most difficult surgeries, even for experienced surgeons. Compared to the traditional surgical procedures, virtual surgical planning can reduce the operation time in operating room while expecting better surgical outcome with optimized planning. However, with existing software systems, it requires much time and manual operations in virtual surgical planning. To reduce preparation time and improve accuracy of virtual surgical planning, we have developed optimized functions for virtual surgical simulation of mandible reconstruction with user-friendly interface. We found that the proposed system shortened the preparation time by half compared to the existing system from the experiments. The proposed system supports surgeons to make accurate plan faster and easier. The virtually planned results are used to make surgical cutting guide by 3D printing, and this will enhance surgical performance in operating room.

• Journal of the Korean Society for Library and Information Science
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• v.29
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• pp.257-279
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• 1995

Cooperative program planning and teaching is a strategy for developing and implementing resource based learning. This approach combines the classroom teacher's subject expertise and knowledge of the students with the teacher­librarian's specialized knowledge of the availability and use of learning materials. And the purpose of cooperative program planning is to develop learning experiences or units of study that effectively integrate the student's resource center activities with other learning experiences. There are also some conditions that are conducive to effective planning sessions. First, the teacher-librarian must be prepared to initiate planning with teachers, rather than waiting for teachers to come to them. Second, the teacher-librarian must be prepared to present suggestions in such a way that the teacher can respond. The purpose of this study is (1) to investigate the planning process of cooperative program planning and teaching in the previous studies and (2) to find general problems when the cooperative program planning and teaching apply in actual situation. For these purposes, I chose a school library and a teacher-librarian in Seoul to observe how this cooperative program planning and teaching carry out in the school library. Main findings are summarized as follows: (1) A teacher who teaches alone for one grade is more proper to carry out the cooperative program planning and teaching. Young teachers are usually more active to change their teaching methods. (2) The cooperative program planning and teaching is a program what needs a lot of materials. When there is no right reference book in a school library, it would be good to access DB through PC telecommunication. It is also possile to contact lirarians who work in large public libraries or university libraries. (3) The cooerative program planning and teaching needs cooperative working between a teacher-librarian and a teacher. Thus a teacher-librarian should be in his school in the day time like the other teachers for the program's planning process. ( 4) There has to be a guide to change into resource based learning in teaching method. Thus the Korean Library Association or Korean Library and Information Science Society should offer a seminar or a workshop about cooperative program planning and teaching for the teacher-librarians. (5) It needs a system that a teacher-librarian can know about student's assignments so that he can prepare reference books for them. (6) The school library can be able to offer excellent service like cooperative program planning and teaching to the teachers and students according to a teacher-librarian's enthusiasm.

• Journal of Korean Society of Rural Planning
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• v.18 no.4
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• pp.35-44
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• 2012

The main contents of revision of the rural landscape planning according to Landscape Law discussed in this study show that the urban landscape and rural landscape have a propulsion system which integrate them into the national landscape and manages through the landscape planning. However, management and conservation reflecting the fundamental difference between urban and rural areas are needed. Planning the landscape by generalizing the size of the population, administrative district, the surface area does not meet the ultimate purpose of the Landscape Law that tries to establish differentiated local landscapes. Therefore, the association of professionals who can support and establish a propulsion system for landscape planning with the consideration of regional characteristics. For the urban landscape, the landscape committee is fulfilling the role, but none is available for the rural areas. This study is mostly based on previous literatures, however, in the future, it is desirable to have selected pilot areas for different landscape types and review problems that may occur during the application and process, in order to establish the landscape guidelines for the rural landscape plan.

• IE interfaces
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• v.3 no.1
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• pp.21-29
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• 1990

This paper presents a linear programming formulation of the aggregate production planning problem for an optical instrument manufacturing company. Taking into account of the various requirements of the company, an L.P model is developed whose objective is to minimize the total cost of production during the planning horizon. The application results and its implications are well understood by the management and expected to be used as a guide line for future production planning.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.619-622
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• 1996

This paper presents the formal integration of process planning and shop floor control with Petri net formalism. Formal integration means that both planning and control problems can be modeled, interfaced, and transformed with the Petri net formalism. This integrated framework provides a systematic approach for rapidly developing a formal shop floor controller from process planning with respect to shop floor configuration.