• Journal of Korean Institute of Industrial Engineers
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• v.22 no.4
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• pp.619-631
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• 1996

This paper describes an approach for the incorporation of maintenance times into a hierarchical scheduling for a failure prone flexible manufacturing system. The maintenance should not be performed too often because of the resulting reduction of capacity. Most manufacturing systems are large and complex. It is natural to divide the control into a hierarchy consisting of a number of different levels. Each level is characterized by the length of the planning horizon and the kind of data required for the decision making process. The goal of the analysis reported here is to calculate the production requirements while the machines fail and are repaired at random times. The machine failure and preventive maintenance are considered simultaneously.

• IE interfaces
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• v.23 no.1
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• pp.78-88
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• 2010

In this paper we develop a model for the performance evaluation of defense R&D test development projects based on analytic hierarchy process. First, evaluation indicators are collected through the related literature survey and a delphi inquiry method. Second, stepwise multiple linear regression is used for developing a hierarchical structure for analytic hierarchy process in the evaluation model, which can make the selected evaluation indicators of the hierarchical structure independent. Also we verify the effectiveness of proposed indicators of the performance evaluation by comparing with the existing evaluation indicators. The developed indicators for the performance evaluation is more reasonable and practical than the previous indicators on defense R&D test development projects.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.52-68
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• 2019

Aiming at the optimal placement of communication relay nodes (OPCRN) problem in manned/unmanned aerial vehicle cooperative engagement system, this paper designed a kind of fully connected broadband backbone communication topology. Firstly, problem description of OPCRN was given. Secondly, based on problem analysis, the element attributes and decision variables were defined, and a bi-level programming model including physical layer and logical layer was established. Thirdly, a hierarchical artificial bee colony (HABC) algorithm was adopted to solve the model. Finally, multiple sets of simulation experiments were carried out to prove the effectiveness and superiority of the algorithm.

• 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.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.5
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• pp.405-411
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• 2011

This paper presents a hierarchical trajectory planning method which can handle a collision-free of the planned path in complex and dynamic environments. A PV (Path & Velocity profile) planning method minimizes a sharp change of orientation and waiting time to avoid a collision with moving obstacle through detour path. The path generation problem is solved by three steps. In the first step, a smooth global path is generated using $A^*$ algorithm. The second step sets up the velocity profile for the optimization problem considering the maximum velocity and acceleration. In the third step, the velocity profile for obtaining the shortest path is optimized using the fuzzy and genetic algorithm. To show the validity and effectiveness of the proposed method, realistic simulations are performed.

• International Journal of Contents
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• v.12 no.1
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• pp.25-43
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• 2016

An agent-centric event planning method is proposed for providing pedagogical experiences in an immersed environment. Two-level planning is required at in a macro-level (i.e., inter-event level) and an intra-event level to provide realistic experiences with the objective of learning declarative knowledge. The inter-event (horizontal) planning is based on search, while intra-event (vertical) planning is based on hierarchical decomposition. The horizontal search is dictated by several realistic types of association between events besides the conventional causality. The resulting schematic plan is further augmented by conditions associated with those agents cast into the roles of the events identified in the plan. Rather than following a main story plot, all the events potentially relevant to accomplishing an initial goal are derived in the final result of our planning. These derived events may progress concurrently or digress toward a new main goal replacing the current goal or event, and the plan could be merged or fragmented according to their respective lead agents' intentions and other conditions. The macro-level coherence across interconnected events is established via their common background world existing a priori. As the pivotal source of event concurrency and intricacy, agents are modeled to not only be autonomous but also independent, i.e., entities with their own beliefs and goals (and subsequent plans) in their respective parts of the world. Additional problems our method addresses for augmenting pedagogical experiences include casting of agents into roles based on their availability, subcontracting of subsidiary events, and failure of multi-agent event entailing fragmentation of a plan. The described planning method was demonstrated by monitoring implementation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10A
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• pp.1461-1472
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• 2000

Recently, the mobile users seem to be rapidly increasing and then the capacity limit will be reached at close hand. In these situations, to provide them with good quality of service in the coming future, newly planned cell design is needed. In the next generation mobile communication systems, namely IMT-2000, good quality services will be possible only by designing the cell structure hierarchically with the help of appropriate cell planning. In the research process, the standardization reports on the future mobile cellular IMT-2000 system (3GPP) are investigated and the parameters, that are essential to cell planning, are also researched. Modeling of IMT-2000 radio link and the numerical analysis on that make it possible to calculate the forward/reverse link budget, system capacity call blocking probability Erlang capacity and cell coverage. In planning the cell of IMT-2000 system, various parameters are considered, such as hierarchical cell structure, number of users, data service forms and propagation area environments. From the results, efficient cell planning methods are proposed. Through this thesis efficient cell planning and maximum capacity will be achieved in the beginning of commercial IMT-2000 service.

• 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.

• Journal of the Korea Society for Simulation
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• v.8 no.1
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• pp.89-99
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• 1999

The major objective of this research is to propose a design architecture for autonomous defense systems for supporting highly intelligent behavior by combining decision, perception, and action components. Systems with such high levels of autonomy are critical for advanced battlefield missions. By integrating a plenty of advanced modeling concepts such as system entity structure, endomorphic modeling, engine-based modeling, and hierarchical encapsulation & abstraction principle, we have proposed four layered design methodology for autonomous defense systems that can support an intelligent behavior under the complicated and unstable warfare. Proposed methodology has been successfully applied to a design of autonomous tank systems capable of supporting the autonomous planning, sensing, control, and diagnosis.

• Journal of Korean Society of Rural Planning
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• v.10 no.2 s.23
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• pp.43-49
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• 2004

According to the growing concerns of the public with efficiency and effects of regional policies, their assessment works have become an important issue. Up to now, several studies have been carried out on economic effects of policies using conventional cost/benefit analysis, while there have been few studies on assessment of amenity oriented policies. From the above consideration, this study tried to develop An Annual Expenditure Assessment Model (AEAM) for amenity-oriented policy-making in rural area. As a pre-work for model development, the hierarchical indices system for rural development and the classification system of expenditure were designed. Being based on high significant relationship between rural amenities and local government expenditure, a linear optimization model for maximization of regional amenity was constructed. Through a case study of Sunchang-gun, Chonbuk-province, the model applicability was ascertained.