• Journal of Astronomy and Space Sciences
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• v.38 no.1
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• pp.65-82
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• 2021

For the vast majority of geostationary satellites currently in orbit, station keeping activities including orbit determination and maneuver planning and execution are ground-directed and dependent on the availability of ground-based satellite control personnel and facilities. However, a requirement linked to satellite autonomy and survivability in cases of interrupted ground support is often one of the stipulated provisions on the satellite platform design. It is especially important for a geostationary military-purposed satellite to remain within its designated orbital window, in order to provide reliable uninterrupted telecommunications services, in the absence of ground-based resources due to warfare or other disasters. In this paper we investigate factors affecting the robustness of a geostationary satellite's orbit in terms of the maximum duration the satellite's station keeping window can be maintained without ground intervention. By comparing simulations of orbit evolution, given different initial conditions and operations strategies, a variation of parameters study has been performed and we have analyzed which factors the duration is most sensitive to. This also provides valuable insights into which factors may be worth controlling by a military or civilian geostationary satellite operator. Our simulations show that the most beneficial factor for maximizing the time a satellite will remain in the station keeping window is the operational practice of pre-emptively loading East-West station keeping maneuvers for automatic execution on board the satellite should ground control capability be lost. The second most beneficial factor is using short station keeping maneuver cycle durations.

• Asia pacific journal of information systems
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• v.29 no.4
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• pp.547-570
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• 2019

With the advances of information technologies, the interest in SmartWork including extended version of telework and flexible work are increasing, and various types of SmartWork attempted to make working time and place flexible with the goal of work and life balance. Despite its emphasis on work and life balance, SmartWork is expected to make the boundaries between work and nonwork blur and role conflicts occur more than before, and thus the goal of work and life balance becomes more distant. A number of SmartWork users are significantly increasing in Korea, but little is known concerning the antecedents and mechanisms to explain psychological work and interferences in the SmartWork environment. In this paper, using boundary theory, we empirically investigate factors affecting the interferences at both work and nonwork domains. The results, based on data collected from SmartWork users in one of the biggest telecommunication companies in Korea where SmartWork is adopted and extensively used, suggest the factors may be affecting differently interferences at the work and nonwork domains.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.880-884
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• 1995

Manufacturing environment is getting characterized by unstable market demand,short product life cycle and timebased competition. For adapting this environment,machine tools have to be further versatile functionally in order to reduce part's set-up time. Unlike existing manufacturing systems mainly to focus on part flow, it is important to control tool flow using fast tool change device and tool delivery device in parallel machines consisting of versatile machine tools, because complete operations on a part can be performed on one machine tool in a single machine set-up. In this paper, under dynamic tool allocation strategy to share tools among machine tools, we propose a real-time tool allocation and operation esequence model with an objective of minimizing flow time using autonomy and negotiation of agents in parallel machines

• Journal of Family Resource Management and Policy Review
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• v.16 no.4
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• pp.1-22
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• 2012

The purpose of this study is to determine the characteristics of Filipino marriage immigrants' acculturation stages in regards to their Korean family life culture and to identify the source of the support for each stage, hence to provide information for educational programs that would promote successful acculturation for each stage. The following findings have been obtained through in-depth interviews with 18 female Filipino immigrants to Korea. In a range of obstacles from the Honeymoon Stage to the Confusion stage, the first are the language and the aspects of the food/cooking/ingredients/diet that are different from their own culture. Especially, pregnancy/childbirth is a major change in one's life and the biggest challenge in the acculturation process. As food and cooking are the first change that the immigrants have to face and get accustomed to in the early stage of their Korean life, the food culture is rather easier for the immigrants to get accustomed to than other parts of Korean life. From the Honeymoon Stage to the Harmony Stage, the immigrants make efforts to help their family in the home, while they look to their future in their children during the Autonomy Stage. Regardless of how long they have been in Korea, from the Honeymoon Stage to the Autonomy Stage, the immigrants have a hard time with the patriarchal environment in Korea due to the bilateral nature of kinship in the Philippines. Secondly, the immigrants receive the most support from their husband, family, and the tutors in Korean culture, while their mothers-in-law are the main source of the support for the Korean diet. At the Confusion Stage, the immigrants start visiting the regional multicultural family support centers and get help from the friends they meet there while depending on the TV for cooking tips. From the Harmony Stage, they may seek a job through the community network with their own effort and their children's help. In the Autonomy Stage, they are concerned about their children rather than their own parents, and they find their own identity as a Korean and realize that their effort is important.

• The Journal of Fisheries Business Administration
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• v.23 no.2
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• pp.53-67
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• 1992

It has been recognized, virtually from the time of its inception, that fisheries economics, like other aspects of resource economics, should ideally be cast in capital-theoretic terms. The fish population or biomass can be viewed as a capital stock in that, like conventional or man-made capital, it is capable of yielding a sustainable consumption flow through time. This study is to introduce the optimal control theory which was extended from the theory of calculus of variations into the study of former static theory of fisheries economics started by Gordon (1954). The optimal control theory eliminated the inadequacies of the classical techniques to a large extent. From this point of view, this study, on the base of Schaefer model, summerizes most of major results achieved so far, but does so in a manner such that the links with capital theory are made transparent. This study explores two sets of problems. The first concerns the optimal approach to the equilibrium stock, i.e. the optimal investment policy. The second set of problems arises from the relaxation of the highly restrictive assumption of autonomy (i.e. the assumption that the parameters are independent of time), then concludes the relaxation of linearity assumption together with the complexities caused by that.

• International Journal of Contents
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• v.12 no.4
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• pp.69-75
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• 2016

Adolescent media addiction has emerged as an important social agenda in Korea. However, there has not been enough discussion on the causal structure of media addiction and policy interventions. The objective of this study is to identify and assess the mechanism of the existing and the revised Shutdown policy based on the systems thinking approach. To achieve this purpose, we establish the relationship between media usage, flow, and addiction, and develop a causal loop diagram. Based on the causal loop diagram, we explore the causal structure of two policy scenarios: shutdown policy and deregulation. Our study suggests that policy interventions inducing direct parental control on children's media usage time are ineffective since the time control reduces children's autonomy, which helps alleviate media addiction. Therefore, this study suggests that policy intervention should focus on alleviating addiction itself rather than on controlling media usage time.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.1-16
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• 1997

This paper improves the autonomy for supplier's schedule and the flexibility of the final assembly line. The final assembly line is a single work station and each product taking different assembly time is considered. In the assembly schedule, the heuristic method based on the goal chasing method is used. Consequently, suppliers can independently determine their output rates and thus, change their workload pattern according to their needs and priorities. Moreover, this flexibility can help to avoid expensive final-assembly-line stoppages in case of sudden part supply disruptions. The sequencing method can be easily implemented into an existing just-in-time system. In addition, the mathematical model was formulated and the algorithm was explained through the flow chart. The numerical example was given and the efficiency of this method is shown through the analysis of computational results of that example.

• Safety and Health at Work
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• v.2 no.4
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• pp.328-335
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• 2011

Objectives: Depressive disorder (DD) is a complex disease, and the assessment of work ability in patients with DD is also complicated. The checklist depression (CDp) has recently been developed to support such work ability assessments and has been recommended for implementation in insurance medicine, starting with an analysis of the organisational and social contexts. The aim of this study was to identify the potential facilitators and barriers in the use of the CDp by insurance physicians (IPs) during work ability assessments of employees on sick leave due to DD. Methods: A qualitative research was conducted based on semi-structured interviews. The participants were IPs with at least one year of work experience in performing work ability assessments. The interviews were audiotaped, transcribed and analysed qualitatively. Results: Ten IPs (7 males, 3 females; mean 53 years) were interviewed. Important facilitators, which emerged for use of the CDp, were an oral introduction for colleagues and staff, support from management, valuing the increased transparency in work ability assessments with using the CDp, having adequate time for assessments as well as modification of the appearance (colour, plasticised form) and content (clarifying aspects of the examples) of the assessment tool. The fear of the loss of autonomy, lack of added value of the CDp, high workload, inadequate instructions and lack of time were mentioned as barriers. Conclusion: Adequate introduction to the use of CDp and the fear of the loss of autonomy of IPs need special attention in planning its implementation.

• The Journal of the Convergence on Culture Technology
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• v.4 no.4
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• pp.401-406
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• 2018

According to the National Security Service of the National Police Agency, intrusion into empty houses increased form 2013 to 2016. Consequentially this statistics seemed that house intrusion, burglary is increasing. Also according to the statistics of Public Prosecutors'Office, a total 203,573 theft crimes occurered in 2016, of which 18.9% were theft after intruding. By reson of this is most frequent case of intrusion and theft, we have been studing the RodSecurityRobot model to enhance security in many factories to manage. In order to care for security to the high place, we have propsed a road guard robot model which controls the ground in cooperation with the robot that manages the ground by using the drones. The robot and the drone move together to autonomy to avoid objects. And they check time interval. they also goes to the charger to charge when there is no battery.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.4
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• pp.425-432
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• 2004

This study for Customer Satisfaction(Customer Focus) by Profit security' in the field Process improvement activity and man-power upgrade in the learning of organization activity or upgrading ability of each peoples. This thesis study on the focus of KAPEC which introduce Toyota system can apply to VM, 3jeong, Right Box and Right Position), 5S, JIT(Just In Time), KAlZEN, KANBAN System, CIM, ERP, DAS an output of Factory. For strategic changes to take place in industry 3 key important factors need to be included ; integration of tasks functions and process, decentralization of information and responsibility and finally simplification of products and product structures. These describes how CIM can be implemented using these factors. This study for (1)System Integration, (2) Help Logistic Problems, (3) Partly facilitated growth. (4) Improved production planning (5) Real-time management. (6) Fast reporting (7) Productivity. Quality. Delivery Up, Cost reduction and Autonomy management, FMS in the Plant etc.