• The Journal of Korea Robotics Society
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• v.2 no.3
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• pp.262-269
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• 2007

Hierarchical Planning based on Abstraction of World Elements and Operators(HiPAWO) is proposed for mobile robots task planning, where abstraction of world elements is used for hierarchical planning and abstraction of operators is used for hierarchical decomposition of abstracted actions. Especially, a hierarchical domain theory based on JAH(Joint of Action Hierarchy)-graph is proposed to improve efficiency of planning, where a number of same actions are included in both adjacent hierarchical levels of domain theories to provide relationships between adjacent hierarchical levels. To show the validities of our proposed HiPAWO, experimental results are illustrated and will be compared with two other classical planning methods.

• The Journal of Korea Robotics Society
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• v.16 no.3
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• pp.283-290
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• 2021

We propose a task and motion planning algorithm for clearing obstacles and wiping surfaces, which is essential for surface disinfection during the pathogen disinfection process. The proposed task and motion planning algorithm determines task parameters such as grasping pose and placement location during the planning process without using pre-specified or discretized values. Furthermore, to quickly inspect many unit motions, we propose a motion feasibility prediction algorithm consisting of collision checking and an SVM model for inverse mechanics and self-collision prediction. Planning time analysis shows that the feasibility prediction algorithm can significantly increase the planning speed and success rates in situations with multiple obstacles. Finally, we implemented a hierarchical control scheme to enable wiping motion while following a planner-generated joint trajectory. We verified our planning and control framework by conducted an obstacle-clearing and surface wiping experiment in a simulated disinfection environment.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.3
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• pp.215-220
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• 2021

As the role of robots expands, flexible task planning methods are attracting attention from various domains. Many task planning frameworks are introduced to efficiently work in a wide range of areas. In order to work well in a broad region with multiple robots, various communication conditions should be controlled by task planning frameworks. However, few methods are proposed. In this paper, we propose mission planning methods according to the communication status of robots. The proposed method was verified through experiments assuming different communication states with a multi-robot system.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.11a
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• pp.350-353
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• 2007

복잡하고 다원화되어 있는 재택건강관리 계획 모델링을 계층적 작업 네트워크 계획을 기반으로 설계하여 분산 네트워크의 성능을 최대한으로 활용한 자동화 계획 설계를 제안하였다. 이를 위하여 SHOP라는 계층적 작업 도구를 이용하여 응급, 주의, 비정상, 정상과 같은 4가지 시나리오 모델에 따른 맞춤형 건강관리 계획 설계를 구현하여 재택건강관리 시스템의 상태분류에 대한 보조 의사 결정 도구로써 적용하였다.

• The KIPS Transactions:PartB
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• v.16B no.6
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• pp.489-496
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• 2009

Hierarchical Task Network(HTN) planning, a typical planning method for effectively taking advantage of domain-specific control knowledge, has been widely used in complex real applications for a long time. However, it still lacks theoretical formalization and standardization, and so there are some differences among existing HTN planners in terms of principle and performance. In this paper, we present an effective way to translate a HTN planning domain specification into the corresponding standard PDDL specification. Its main advantage is to allow even many domain-independent classical planners to utilize domain-specific control knowledge contained in the HTN specifications. In this paper, we try our translation-based approach to three different domains such as Blocks World, Office Delivery, Hanoi Tower, and then conduct some experiments with a forward-chaining heuristic state-space planner, FF, to analyze the efficiency of our approach.

• Safety and Health at Work
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• v.12 no.2
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• pp.154-166
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• 2021

Background: Occupational health and safety (OHS) is a significant interest of all governments to prevent workplace hazards. Although appropriate legislation and regulations are essentials for the protection of workers, they are solely not enough. Application of them in practice should be secured by an efficient inspection system. Fundamental components of an inspection system are inspectors and their audit tasks. Maintaining the fair balanced task assignment among inspectors strictly enhances the efficiency of the overall system. Methods: This study proposes a two-phased goal programming approach for OHS inspectors' task assignments and presents a case study. Results: The solution approach gives the balanced assignment of inspectors to the workplaces in different cities of the country in the planning period. The obtained schedule takes into account the distances covered by the work places and the number of the workplaces' employees to be audited and pays attention to the human factors by considering the preferences of the inspectors. The comparisons between the obtained optimal schedule and the implemented one that is produced manually show that the approach not only maintains the technical requirements of the problem, but also provides social and physical balance to the task assignment. Conclusion: Both the approach and the application study are expected to offer fruitful inspirations in the area of safety management and policy and they provide a good guide for social policy and organizational aspects in the field of OHS inspectors' task assignment.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.285-294
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• 2023

Autonomous radiation source detection has long been studied for radiation emergencies. Compared to conventional data-driven or path planning methods, deep reinforcement learning shows a strong capacity in source detection while still lacking the generalized ability to the geometry in unknown environments. In this work, the detection task is decomposed into two subtasks: exploration and localization. A hierarchical control policy (HC) is proposed to perform the subtasks at different stages. The low-level controller learns how to execute the individual subtasks by deep reinforcement learning, and the high-level controller determines which subtasks should be executed at the current stage. In experimental tests under different geometrical conditions, HC achieves the best performance among the autonomous decision policies. The robustness and generalized ability of the hierarchy have been demonstrated.

• IE interfaces
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• v.6 no.2
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• pp.53-65
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• 1993

This paper deals with the development of a software module for production planning and scheduling activities of an existing Flexible Machining and Assembly System (FMAS). The Production Planning Module uses the hierarchical and sequential scheme based on "divide and conquer" philosophy. In this module, routes are determined based on the production order, orders are screened, tools are allocated, and order adjustments are executed according to the allocated tools. The Scheduling Module allocates the resources, determines the task priority and the start and completion times of tasks. Re-scheduling can be done to handle unforeseen situations such as lumpy demands and machine breakdowns. Since all modules are integrated with a central database and they interface independently, it is easy to append new modules or update the existing modules. The result of this study is used for operating the real FMAS consisting of a machining cell with 2 domestic NC machines and a part feeding robot, an assembly cell with a conveyor and 3 robots, an inspection cell, an AGV, an AS/RS, and a central control computer.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.5
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• pp.442-449
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• 2013

In this paper, a simulation system based on X-Plane and MATLAB/Simulink for multiple UAVs is presented. For the conceptual design of this proposed system, a hierarchical system architecture for multiple UAVs is presented. This architecture has object-oriented data structure which consists of three objects (UAV status, mission and task, and environment) and a hierarchy consisting of four layers (decision making layer, task assignment layer, path and motion planning layer, and collision avoidance layer) is also proposed. In addition, this paper shows a implementation of simulation system based on the proposed system architecture using X-Plane and MATLAB/Simulink. The result of simulation from the developed system in this paper validate capability of application for multiple UAVs in real environment.

• Journal of Family Relations
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• v.22 no.4
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• pp.53-80
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• 2018

Objectives: The purpose of this study was to investigate individual awareness variables influencing emotional, normative, and functional marriage intentions of unmarried men and women. Independent variables were values of offspring, perceptions to unmarried life, attitudes toward multiple role planning, perceptions and availabilities of marriage-related policies, views on the marriageable age, psychological burdens of pressure to marriage by significant people, and views on parents' support for marriage fund. Method: 553 unmarried men and women in Daegu, Korea were surveyed, and the data were analyzed using descriptive statistics, factor analysis, multivariate analysis of variance(MANOVA), multiple regression analysis, and hierarchical regression analysis with SPSS 22.0. Results: First, this study was more exploratory and in-depth approach to marriage intentions than precedent studies. The sub factors of marriage intentions were emotional, normative, and functional marriage ones. Second, emotional marriage intention showed significant differences depending on gender, dating, views on the marriageable age, and degree of acceptance of parents' support for marriage fund. Among the individual awareness variables, values of offspring, perceptions to unmarried life, attitudes toward multiple role planning, and psychological burdens of pressure to marriage personally or by friends influenced emotional marriage intention. Third, normative marriage intention showed significant differences depending on gender, religion, occupational status, employment condition, dating, views on the marriageable age, and degree of acceptance of parents' support for marriage fund. Among the individual awareness variables, values of offspring, perception to unmarried life, attitudes toward multiple role planning, view on the marriageable age, availabilities of marriage-related information offering policies, and psychological burdens of pressure to marriage by mother influenced normative marriage intention. Fourth, functional marriage intention showed significant differences depending on gender, job, parents' support for marriage fund, views on the marriageable age, and degree of acceptance of parents' support for marriage fund. Among the individual awareness variables, functional marriage intention was influenced by values of offspring, perception about unmarried life, attitudes toward multiple role planning, and degree of acceptance of parents' support for marriage fund. Finally, the hierarchical regression analysis showed that individual awareness variables influenced on marriage intentions. Especially, values of offspring, perceptions to unmarried, and attitudes toward multiple role planning influenced on emotional, normative, and functional marriage intentions in common. Conclusions: The findings from these analyses suggest that the selective process based on the individual awareness has become very significant to having marriage intentions. Therefore, this study will contribute as the basic data on national marriage-related policies. Furthermore, this study will be able to use to think about the marriage intention as a task to be preceded by the national policy in order to prepare for Korea 's low fertility and aging phenomenon.