• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.299-299
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• 2000

In this paper, a determination method of number of AGVs fer introducing to the multi-path material handling systems is presented by using genetic algorithm. For serving the raw material to each work stations automatically, there needs to introduce a AGVs for transfer the raw martial. To reduce the overall production cost in the material handling systems, however, a trade off exists between the amount of inventory hold on the shop floor and the number of AGVs needed to provide adequate service. In this paper, firstly a objective function which included the net present fixed costs of each stations and each purchased AGVs, delivering cost. stock inventory cost, and safety stock inventory cost is presented. Secondly by using genetic algorithm, the optimal reorder quantity at each stations is decided, where the number of AGVs is increased step by step. From a simulation with different GA parameters, we can determine a optimal number of AGVs to reduce the overall production cost. Thus, the effectiveness of GA for determining the number of AGVs is verified in automated material handling systems.

• Earthquakes and Structures
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• v.8 no.3
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• pp.713-732
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• 2015

The application of the compressive force path method for the design of earthquake-resistant reinforced concrete structural walls with a shear span-to-depth ratio larger than 2.5 has been shown by experiment to lead to a significant reduction of the code specified transverse reinforcement within the critical lengths without compromising the code requirements for structural performance. The present work complements these findings with experimental results obtained from tests on structural walls with a shear span-to-depth ratio smaller than 2.5. The results show that the compressive force path method is capable of safeguarding the code performance requirements without the need of transverse reinforcement confining concrete within the critical lengths. Moreover, it is shown that ductility can be considerably increased by improving the strength of the two bottom edges of the walls through the use of structural steel elements extending to a small distance of the order of 100 mm from the wall base.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.1
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• pp.59-67
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• 2003

PMI(Privilege Management Infrastructure) certificates as well as Public-Key certificates must be validated before being used. Validation for a PMI certificate requires PMI certificate path validation, and PKC(Public-Key Certificate) path validations for each entity in the PMI certificate path. This validation work is quite complex and burdened to PMI certificate verifiers. Therefore, this paper suggests a delegated PMI certificate validation that uses specialized validation server, and defines a validation protocol which is used between validation server and client.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.4
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• pp.1249-1265
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• 2022

Video streaming has become one of the most popular applications for mobile devices. The network bandwidth required for video streaming continues to exponentially increase as video quality increases and the user base grows. Multi-Path TCP (MPTCP), which allows devices to communicate simultaneously through multiple network interfaces, is one of the solutions for providing robust and reliable streaming of such high-definition video. However, mobile video streaming over MPTCP raises new concerns, e.g., power consumption and cellular data usage, since mobile device resources are constrained, and users prefer to minimize such costs. In this work, we propose a mobile video streaming framework over MPTCP (mDASH) to reduce the costs of energy and cellular data usage while preserving feasible streaming quality. Our evaluation results show that by utilizing knowledge about video behavior, mDASH can reduce energy consumption by up to around 20%, and cellular usage by 15% points, with minimal quality degradation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.131-133
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• 2010

As linear scheduling method has been used since 1929, Empire State Building linear schedule, it is being applied in various fields such as construction and manufacturing. When addressing concurrent critical path occurring on linear schedule of construction, the empirical researches stress the resource management which should be applied for optimizing work flow, flexible work productivity and continuos resource allocation. However, work relationships has been usually overlooked for making the linear schedule from existing network schedule. Therefore, this research analyze the previous researches related to linear scheduling model and then propose the method that can be applied for adopting the relationships of network schedule to the linear schedule.

• Journal of the Korean Society of Food Culture
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• v.33 no.1
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• pp.26-35
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• 2018

This study conducted an empirical analysis of the effects of job characteristics on work-family conflict relation and quality of life, as well as moderating effects in accordance with operation type, by targeting 245 dietitian/cooks working for contract foodservice companies. The results of this study are as follows. First, the autonomy and feedback had negative (-) effects on work-family conflict while functional diversity had positive (+) effects on work-family conflict. Job identity and job importance had no relation with work-family conflict. Second, work-family conflict had negative (-) effects on job satisfaction, work-family relation, job support, general happiness, and job environment while having positive (+) effects on job stress. Third, in all paths except for the path with effects of work-family conflict on job stress, there were no differences between the group of shops operating 365 days and the group of shops operating 5 days a week. It would be helpful to the effective operation of human resources by emphasizing the necessity of differentiated management for companies with shops operating 365 days and shops operating 5 days a week, as well as managing employees' job characteristic factors, work-family conflict, and even quality of life.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.393-398
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• 2001

This paper aims to work process of connecting rod die using CAD/CAM/CNC systems. CAD/CAM/CNC systems are consist of CAD(MDT4.0), CAM(Z-MASTER) software and CNC milling machine. CAM software is purpose to G-code generation for CNC programming. Then CAM software and CNC milling machine are connect to RS-232-C cable for data network.

• Journal of Advanced Navigation Technology
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• v.17 no.6
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• pp.633-637
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• 2013

By using geolocation and maps, we need to trace the path of ourselves, others, or the objects. Until now, we used a native apps development mehod to develop path tracking systems in mobile devices such as smart phones and tablet computers. A disadvantage of this method is that we have to work again to provide the same service on different platforms. Web Apps and Hybrid Apps are developed to recover this disadvantage. Since Hybrid Apps look like Native Apps apparently, users prefer Hybrid Apps to Web Apps. In this paper, we develop a hybrid app which can trace the path on mobile devices. The recently suggested next generation markup language, HTML5, has geolocation features. By using them, we implemented a hybrid app for a path tracking system. First, we create a web app using HTML5, CSS, and JavaScript, Then, PhoneGap, a mobile development framework, is used to convert it to the hybrid app. By implementing hybrid app, various apps which need path tracking can be developed rapidly and effectively, regardless of the mobile devices.

• Journal of Drive and Control
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• v.20 no.4
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• pp.27-34
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• 2023

Weeding in orchards is closely associated with productivity and quality. The customary weeding process is both labor-intensive and time-consuming. To solve the problems, there is need for automation of agricultural robots and machines in the agricultural field. On the other hand, orchards have complicated working areas due to narrow spaces between trees and amorphous terrain. Therefore, it is necessary to develop customized robot technology for unmanned weeding work within the department. This study developed a path generation and path control method for unmanned weeding according to the orchard environment. For this, the width of the weeding span, the number of operations, and the width of the weeding robot were used as input parameters for the orchard environment parameters. To generate a weeding path, a weeding robot was operated remotely to obtain GNSS-based location data along the superheated center line, and a driving performance test was performed based on the generated path. From the results of orchard field tests, the RMSE in weeding period sections was measured at 0.029 m, with a maximum error of 0.15 m. In the steering period within row and steering to the next row sections, the RMSE was 0.124 m, and 0.047 m, respectively.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.7
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• pp.335-341
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• 2020

The study aims to examine the relationship between talent management and work engagement and its impact on nurses' performance in Indonesia. This study is also intended to understand the role of work engagement in moderating talent management and employee performance. This present study applied a quantitative method using path analysis to investigate the relationship between variables and the primary role of work engagement. The participants of the study were nurses both in privates and public hospitals in Indonesia, with a total of 376 respondents. Closed questionnaires were processed in this study with a Likert scale with five choices ranging from 1 (strongly disagree) to 5 (strongly agree). The questionnaires were entirely collected over almost five months using Google form. The results of the study confirmed that the nurse performance, both at government and private hospitals, are categorized as good, while the work engagement and talent management are also categorized as high. The findings confirmed that talent management positively influences work involvement and employee performance. In addition, this study suggests that work engagement plays an essential role in moderating between variables and provides a confirmation of the important role of talent management and work engagement for nurses' performance.