• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1838-1854
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• 2023

This paper presents a hybrid algorithm to solve the multi-objective path planning (MOPP) problem for mobile robots in a static nuclear accident environment. The proposed algorithm mimics a real nuclear accident site by modeling the environment with a two-layer cost grid map based on geometric modeling and Monte Carlo calculations. The proposed algorithm consists of two steps. The first step optimizes a path by the hybridization of improved ant colony optimization algorithm-modified A^* (IACO-A^*) that minimizes path length, cumulative radiation dose and energy consumption. The second module is the high radiation dose rate avoidance strategy integrated with the IACO-A^* algorithm, which will work when the mobile robots sense the lethal radiation dose rate, avoiding radioactive sources with high dose levels. Simulations have been performed under environments of different complexity to evaluate the efficiency of the proposed algorithm, and the results show that IACO-A^* has better path quality than ACO and IACO. In addition, a study comparing the proposed IACO-A^* algorithm and recent path planning (PP) methods in three scenarios has been performed. The simulation results show that the proposed IACO-A^* IACO-A^* algorithm is obviously superior in terms of stability and minimization the total cost of MOPP.

• Korean Journal of Construction Engineering and Management
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• v.7 no.1 s.29
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• pp.148-158
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• 2006

Public construction companies have strictly followed a rule that they should not do the works using water such as concrete pouring for the structural frame for a certain period during the winter season. It is usually known that the designated non-working period during the winter causes increase of the project duration and the project cost escalation. The halted work also makes negative effects on national economy because it reduces worker's income. However, the situation would be a lot better if the work for the structural frame is allowed under some conditions. The structural framework done alone without being followed by finish works gives a lot of stresses on the finish works. In this sense, this study examines how the structural framework performed during the winter season affect on the critical path of the finish works. To accomplish the objective of this research, the subnet for the finish works as well as a master network are prepared along with critical paths for a virtual construction site. Using the prepared networks, simulations are carried out to see the effects described above. This study is expected to be used in estimating the construction duration of high-rise apartment housing when the site work for the structural frame should be performed during this period.

• 한국사회정책
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• v.19 no.3
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• pp.215-245
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• 2012

The purpose of this study is to examine pathways of factors that influence job satisfaction for full-time and part-time married female employees with children of 18 or under and to compare path coefficients for two groups. Simultaneously analyzing multiple populations, we found that the path model was appropriate for both groups with significant differences in path coefficients. Income, workplace size, husband's support for wife's work, and work-to-family conflict had direct effects on job satisfaction for both groups whereas health had a direct effect only among full-time workers. Family-to-work conflict had an indirect effect for both types of workers, while health had an indirect effect among full-time employees only, and income and having children under school age among part-time employees only. The results indicate that differentiated approaches to increase job satisfaction for full- and part-time employees are needed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.1
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• pp.41-47
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• 2002

Path setup considering QoS is one of the main problems to solve in Internet traffic engineering. In network restoration that is one of the traffic engineering components, to establish a backup path or backup path for a working path to be protected is the main task. The backup path should have enough bandwidth to guarantee the working paths. Thus this work requires the QoS routing solution that is to set up a backup path as well as a working path at the same time provisioning enough bandwidth. In this paper, we propose an algorithm to setup a backup path that shares the bandwidth of other backup paths whose working path does not pass along the same link with the working path we are considering. In this way we can reduce much bandwidth consumption caused by setting up backup paths. We also analyze the disjoint path computation algorithms. Finally we show simulation results how the algorithm can reduce the bandwidth consumption and how it will affect blocking when we setup paths.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.265-282
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• 2015

This study with qualitative research method explores the process of a middle-aged woman who finds and constructs her career path. As a result, career constitution process of a research participant choosing a career to make a living and carrying out what she is supposed to do, turned out to be more than just a job adaptation process in the workforce. Career constitution process is a journey in search of "genuine self" and a existential process in which the existence of self is understood by sustained choices and "actions." The research participant on the life journey of finding career path sought to return to her intrinsic life and practiced self-realization toward possibility. The result of this study suggests that "work" being different from calling needs to be understood anew in the existential perspective. "work" is not only a passage which makes the meaning of life by existential "actoins" but also a existential method heading toward self-realization. Not only that, career path is a process which doesn't get obvious by one choice but is unfolded by shaking between potential energy and possibilities accumulated by here and now decisions and actions. Thus, the researcher of this study suggests that counselling for career path should go beyond the linear task which figures out a person's aptitude, the features of the workforce and connects both. And there is the need for a paradigm shift in totally understanding the client's life and in making the meaning of a work in the process of finding genuine "self".

• Asia-Pacific Journal of Business
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• v.10 no.3
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• pp.95-112
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• 2019

It is important for the Startup team to enhance their employee's work & life balance in recent ages. this study is to research the effect of work & life balance on organizational pride, job satisfaction and performance. Also, we explore how the organizational climate which compose with autonomy, leader's support and trust affects work & life balance. This study analyzed the path effect with PLS method using data from 151 Startup teams. The results of analysis are as follows. First, it was confirmed that supervisor's support, trust of team climate positively influence work & life balance but autonomy is not confirmed to have the relationship with work & life balance. Second, work & life balance have a positive effect on organizational pride and job satisfaction. In addition, this study shows that organizational pride and job satisfaction have the relationship between work & life balance and team performance. Also, Startup team managing the work & life balance will get better performance and retain the competition.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4D
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• pp.433-442
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• 2010

Recent decrease in the availability of experienced skilled labor and a corresponding lack of new entrants has required the need for automating many of the construction equipment used in the construction industry. In particular, excavators are widely used throughout earthwork operations and automating its tasks enables work to be performed with higher productivity and safety. This paper introduces an optimal path generation method which is one of the core technologies required to make "Intelligent" excavators a reality. The method divides a given earthwork area into unit cells, identifies networks created by linking these cells, and identifies the optimal path an excavator should follow to minimize its total transportation costs. In addition, the method also accounts for drainage direction and path continuity to ensure that the generated path considers site specific conditions.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.118.5-118
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• 2002

To apply induction hardening method to a press die having 3-D free surface, the induction hardening tool moves on a press die above 1～2mm gap with constant velocity. Since the induction hardening process requires its own hardening path for each die, a direct teaching method which generates working path directly guided by operators is more suitable than an offline method using CAD/CAM data. The direct teaching apparatus in this work includes a teaching tool with a force/torque sensor and data processing computer to finally generate robot's Induction hardening program , in direct teaching operation, an operator teaches working path maintaining contact with surface of press die by holding...

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.6
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• pp.426-431
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• 2015

In this work, a new type of MR damper with additional flow path in piston is proposed and damping force characteristics are numerically evaluated. Flow-mode type MR damper is considered and mathematical model is established based on Bingham rheological model of MR fluid to obtain accurate prediction of damping force characteristics. Damping force of the proposed MR damper are calculated with respect to piston velocity and input current. In addition, investigation on damping force characteristics is carried out according to number of additional flow path and excellence of the proposed MR damper is demonstrated.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.19-24
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• 1992

Real-time mobile robot controllers usually have been designed with an emphasis on control theory ignoring the importance of system integration. This paper demonstrates that useful mobile robots require a real time controller with a wide range of capabilities in addition to control theory. These capabilities include: path-planning, position estimation, path tracking control and wheel control. An architectural framework supporting these capabilities has been designed and implemented. Using this frame work, individual modules such as a path planner, a path tracking controller, position estimators, wheel controllers and other cruical elements have been successfully integrated into the control system for the LCAR robot which was developed as a proto-type mobile robot in our laboratory. The context of the research, the architecture, its implementation and performance results from experiments are discussed.