• Journal of the Korea Society for Simulation
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• v.17 no.4
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• pp.133-142
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• 2008

AGV systems are widely used to increase the flexibility and the efficiency of the material handling systems. AGV systems are one of critical factors which determine the overall performance of the manufacturing systems. To this end, the optimal design for AGV systems is essential. Commercial simulation software is often used as an analysis tool during the design of AGV systems, however a series of procedures are desirable to simplify the analysis processes. In this paper, we present and develop the architecture for unidirectional AGV systems simulator which is able to consider approximate optimal unidirectional flow path and various operational parameters. The designed AGV systems simulator is based on JAVA, and it is developed to support designing approximate optimal unidirectional network by using Tabu search method. In addition, it enables users to design and evaluate AGV systems and to analyze alternative solutions easily. Simulation engine is consists of layout designer, AGV operation plan designer, and integrated AGVS layout designer. Users enter their system design/operation information into input window, then the entered information is automatically utilized for modeling and simulating AGV systems in simulation engine. By this series of procedures, users can get the feed back quickly.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.9
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• pp.782-789
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• 2018

Multi-Function Display (MFD) of Korean Utility Helicopter (KUH) displays image information(navigation, flight, topographical and maintenance information) delivered from Mission Computer (MC) during flight operation. The abnormal display of MFD such as flickering phenomenon was identified in the system development. It was solved by improving the shielding performance of the DVI cable and changing the DVI cable installation path at the first mass production. However, it was occurred again when the aircraft was operated for one or two years after delivery. It was also identified in the evaluation process of the derivative helicopters. Therefore, a comprehensive review of the aircraft system level has been performed to solve the problem of MFD malfunction at first and then a design improvement plan was derived by improving the DVI cable. In this paper, the causes of MFD anomalies are analyzed and also the process of design improvement are summarized. The validity of the improvement has been verified through the DVI cable assembly comparison test, SIL/ground/flight test.

• Smart Media Journal
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• v.5 no.2
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• pp.42-50
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• 2016

In case of a emergency situation or a natural disaster, a warning notification system is an essential tool to notify at-risk people in advance and provide them useful information to survive the event. Although some systems have been proposed such as emergency alert system using android, SMS, or P2P overlay network, these works mainly focus on a reliable message distribution methods. In this paper, we proposed a novel design and implementation of a personalized warning notification system to help inform not only the at-risk people but also their family and friends about the coming disaster as well as escape plan and survival information. The system consists of three main modules: the user selection module, the knowledge based message generator, and message distribution modules. The user selection module collects the list of people involved in the event and sorts them based on their level of involvement (their location, working position and social relationships). The knowledge based message generator provides each person with a personalized message that is concise and contains only the necessary information for the particular person based on their working position and their involvement in the event. The message distribution module will then find a best path for sending the personalized messages based on trustiness of locations since network failures may exist in a disaster event. Additionally, the system also have a comprehensive database and an interactive web interface for both user and system administrator. For evaluation, the system was implemented and demonstrated successfully with a building on fire scenario.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.4
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• pp.177-183
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• 2015

Incremental sheet metal forming is a manufacturing process to produce thin parts using sheet metals by a series of small incremental deformation. The process rarely needs dedicated dies and molds, thus, preparation time for the process is relatively short as to be compared to conventional metal forming. Spring back in sheet metal working is very common, which causes critical errors in dimensions. Incremental sheet metal forming is not fully investigated yet. Hence, incremental sheet metal forming frequently produces inaccurate parts. This paper proposes a method to minimize dimensional errors to improve shape accuracy of products manufactured by incremental forming. This study conducts experiments using an exclusive incremental forming machine and the material for these experiments are sheets of aluminum AL1015. This research defines a process parameter and selects a few factors for the experiments. The parameters employed in this paper are tool feed rate, tool diameter, step depth, material thickness, forming method, dies applied, and tool path method. In addition, their levels for each factor are determined. The plan of the experiments is designed using orthogonal array $L_8$ ($2^7$) which requires minimum number of experiments. Based on the measurements, dimensional errors are collected both on the tool contacted surfaces and on the non-contacted surfaces. The distances between the formed surfaces and the CAD models are scanned and recorded using a commercial software product. These collected data are statistically analyzed and ANOVAs (analysis of variances) are drawn up. From the ANOVAs, this paper concludes that the process parameters of tool diameter, forming depth, and forming method are the significant factors to reduce the errors on the tool contacted surface. On the other hand, the experimental factors of forming method and dies applied are the significant factors on the non-contacted surface. However, the negative forming method always produces better accuracy than the positive forming method.

• Journal of Convergence for Information Technology
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• v.11 no.10
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• pp.115-130
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• 2021

This study is to study the overall structural relationship between work-life balance(WLB), superior trust, workplace happiness, and organizational commitment. The goal of this study is to study how WLB and superior trust affect workplace happiness, how workplace happiness affects organizational commitment, and the mediating effect of workplace happiness. Survey data were collected from incumbents working in large companies and SMEs, validity and reliability of research items were reviewed, and research hypotheses were tested using path analysis. As a result of testing the research hypothesis, WLB and superior trust have a positive (+) effect on workplace happiness, and workplace happiness has a positive (+) effect on organizational commitment. Also, job satisfaction plays a role as a partial parameter between WLB, superior trust, and organizational commitment. Based on the hypothesis test results, it was confirmed that the higher the level of WLB and superior trust, the higher the level of work satisfaction. Based on the research results, a plan was suggested for Korean corporate members to achieve workplace happiness and organizational commitment.

• 한국사회정책
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• v.25 no.1
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• pp.231-257
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• 2018

Japan has generally been considered as the developmentalist welfare state. However, Japan has recently been transformed into a social investment state. Although it still has a developmentalist characteristics with its institutional path dependence, the new social and economic challenges derived from the new social risks such as low birth rates and aging population forced Japan to adopt a new welfare state strategy. The paradigm shift in terms of welfare state strategy was launched by the Third Way positioning of the Democratic party government and succeed to the Second Stage of Abenomics under the Third Abe Cabinet. This paper argues that the welfare state paradigm shift towards a social investment state in Japan is not limited to the Japan's Plan for Dynamic Engagement of All Citizens for a virtuous cycle of growth and distribution, but expands its scope to include the work-family balance policies such as labor market activation for women and public caring for children.

• Journal of Radiation Protection and Research
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• v.44 no.1
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• pp.43-52
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• 2019

Background: The mid-term performance of clinical linear accelerator (LINAC) during volumetric modulated arc therapy (VMAT) treatment period is not performed in clinical practice and usually replaced with one-time plan quality assurance (QA). In this research we aim to monitor daily reproducibility of VMAT delivery from tracking individual leaf movement error and dosimetric error to evaluate the mid-term quality of the machine used. Materials and Methods: First, multileaf collimator (MLC) information was imported into MATLAB program to determine which of the MLC leaves in the leaf bank had the maximum RMS position error (maxRMS). We estimated where the maximum positional errors (maxPE) of the chosen leaf occur along its path length and tracked its daily variations over the entire treatment period. Secondly, picture information of dosimetric error from portal dosimetry was imported into MATLAB where representative high gamma index region (HGR) was determined as HGR with length of > 1 cm and their centers were daily tracked. Results and Discussion: The maxPEs in the brain and tongue cases were distributed broader than in other cases, but all data were found located within ${\pm}0.5mm$. From first day to last day all of five cases show the similar visual pattern of HGRs and Centers of the longest HGRs remained within ${\pm}1mm$ of that in first day. These findings prove excellent mid-term performance of the LINAC used in VMAT treatments over a full course of treatment. Conclusion: Tracking the daily location changes of leaf movement and dosimetric error can be a good indicator of predicting the daily quality like stability and reproducibility of beam delivering in VMAT treatment.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.376-387
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• 2019

The role of local decentralization and balanced regional development becomes important due to the concentration of population due to urbanization, and the development of tourism contents in local governments is actively being attempted. However, this is largely due to quantitative growth, and it does not offer tourist content that offers a different experience while utilizing regional characteristics. This means that it is important to develop programs and contents that emphasize the identity of the region by cultivating local characteristics and build a different image. However, most of the small regions where characteristic resources are difficult to find have a problem that it is difficult to develop different programs and contents due to relatively few development opportunities and financial constraints. In this study, it was considered that it is effective to analyze characteristic features of the region and utilize the possessed assets as much as possible. Therefore, we propose a service design process that effectively supports ecotourism, one of the regional revitalization plan using local eco - assets. In the process, Venn Diagram Position and Context Map methodology was developed and verified through Sutonggol Observation Path.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.6
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• pp.530-538
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• 2020

Safety inspections of outdoor advertisements are conducted to determine the aging status, specifications, and compliance with design documents. Regular inspections are conducted on outdoor advertisements from a safety perspective, as they not only undermine the aesthetic elements of the city but also could cause falls on roads or pedestrian paths. However, the current safety inspection methods are at risk of various accidents during the inspection advertisements on the outer wall of the building. And it is difficult to conduct in-depth inspections on them if they are fixed to the elevation of the building. Furthermore, there also is a risk of safety accidents, such as advertising structures falling onto a pedestrian path. Therefore, this paper aims to enhance the safety inspection system of outdoor advertisements using drones. This paper also intends to propose measures for facility inspection history management such as safety inspection cycle, maintenance, and removal of signboards.

• Journal of Information Technology Services
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• v.20 no.5
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• pp.137-146
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• 2021

Recently, public participation in government policy design has been further expanded and public services perceived by users are expanding. At this time, the role of the digital government and the direction of the service to be pursued are user-centered, and above all, it is necessary to focus on the keywords of pre-emptive, preventive, and customized. In order to propose service quality improvement in the public sector, service user-centered classification and monitoring are integrated and the usability of government documents is improved. It is necessary to identify the needs of whether to provide a path for public participation. In the post-corona era, people are accessing quarantine information from the digital government every day. The government should proactively respond to the acceleration of digital transformation and the non-face-to-face demands of the people who experience non-face-to-face daily life. In order to evolve into a smart organization along with the innovation promotion plan and to provide customized services, it is necessary to use existing guides for institutional and technical improvement, along with new technology and data-based analysis, to strive for change management. The government should seek counter-measures that have advanced one step ahead by incorporating new high-tech IT with user-centered necessary services. This study aims to derive improvement plans to provide user-centered digital government service design when designing public services and collecting public opinions. Based on the e-government development model research and the existing research on user-centered service design in the public sector, institutional and technical measures are provided for the improvement of digital government service design.