• Journal of Aerospace System Engineering
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• v.13 no.3
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• pp.23-31
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• 2019

The design requirements of modern satellites vary depending on the purpose of operation. Like conventional medium and large-scale satellites, small satellites which operate on low orbit may also serve military purposes. As a result, there is increased demand for high-resolution photos and videos and multi-target observation becomes important. The most important design parameter for multi-target observation is the satellites' maneuverability. For increased maneuverability, the miniaturization is required to increase the stiffness of the satellite as this decreases the mass moment of inertia of the satellite. In the case of a solar panel having relatively low stiffness compared to the satellites' body, vibrations are generated when the attitude maneuver is performed, which greatly influences the image acquisition. For verification of such vibrational characteristics, the satellites is modeled as a reduced model, and experimental zig for simulating attitude maneuver is introduced. A rigidity simulator for simulating the stiffness of the satellite is also proposed. Additionally, the objective of the experimental method is to simulate the maneuvering angle of the satellite based on the winding length of the wire using a step motor, and to experimentally verify the vibration characteristics of the satellite body and the solar panel generated during the maneuvering test.

• The Korean Journal of Archival Studies
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• no.32
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• pp.177-217
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• 2012

The National Archives of Korea(NAK) has a mission to ingest large-scaled digital records and information from a number of different government agencies annually from 2015. There are important issues related to the digital records and information transfer between NAK and agencies, and one of them is how to configure deployment of digital repositories for the archives management systems. The purpose of this paper is to offer the way to design it by examining the checkpoints through the whole life cycle of digital records and information in the archives management systems and calculating the amount of ingested digital records and information to the systems in 2015 and deploying the digital repositories configured according to the amount the records and information. Firstly, this paper suggests that the archives management systems in NAK should be considered and examined into at least three different parts called Ingest tier, Preservation tier and Access tier in aspects to the characteristics of the flow and process of the digital records and information. Secondly, as a results of the calculation the amount of the digital records and information ingested to the archives management systems in 2015 is sum up to around 2.5 Tera bytes. This research draws several requirements related to the large-scaled data and bulk operations which should be satisfied by the database or database management system implemented on to the archives management systems. Thirdly, this paper configures digital repositories deployment according to the characteristics of the three tiers respectively. This research triggers discussion in depth and gives specific clues about how to design the digital repositories in the archives management systems for preparing the year of 2015.

• The Korean Journal of Franchise Management
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• v.10 no.2
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• pp.59-70
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• 2019

Purpose - Every company studies how to attract and retain new customers to increase competitiveness and profitability. Companies establish strategies to attract customers, secure competitive advantage and generate revenue. Businesses are looking for newer and better ways to differentiate themselves in the marketplace. One of the requirements for service differentiation is to make it a prerequisite for an engaging customer experience. Customer experience can be attained through service experience. Satisfaction determine whether to reuse the food service franchise. The purpose of this study is to investigate the effect of customer experience on the satisfaction and revisit intention of food service franchise. In this study, customer experience consists of three attributes such as service environment, food quality, and price fairness. Also, this study is to identify the importance of three service experience attributes of customer satisfaction and revisit intention using ANN (artificial neural network) analysis. Research design, data, methodology - The survey was conducted on customers who have visited franchise restaurants in one month in order to examine how service environment, food quality, and price fairness have been influenced customer satisfaction and revisit intention through online survey company (SM culture & contents). A total of 300 representative surveys were collected. Of those collected surveys, 26 were not used due to missing information, resulting in 274 as the final sample size. The sample size was more than 10 times more than the number of variables used in the structural model analysis. Results - The findings of this study are as follows: Service environment and price fairness have a significant effect on satisfaction. However, food quality did not have a significant effect on satisfaction. Finally, it was found that satisfaction had a significant effect on revisit intention. Meanwhile, according to the results of ANN analysis, satisfaction as a dependent variable was found to be the most important in male price fairness and service environment in female. Also, when the revisit intention is used as a dependent variable, both male and female price fairness are important. Also, when the intention to revisit is used as a dependent variable, both male and female price processes are important. Conclusions - First, a restaurant franchise enterprise needs to manage customer service experience. Customers should strive to eat and enjoy at a dining franchise store. Second, it is necessary to design a food service franchise shop as a customer-oriented service environment. Franchise companies need to improve the environment so that customers can use the store conveniently. Third, the restaurant franchise menu price needs to be cheaper than the alternative menu. The restaurant franchise menu needs to be constructed with a popular menu that can be used continuously by the customer, so that it can be set at a reasonable price.

• The Journal of Sustainable Design and Educational Environment Research
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• v.19 no.4
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• pp.26-39
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• 2020

This study analyzed the usage characteristics and requirements of students who are users of the middle school education space, and the following results were obtained: First, we could see that various types of classes were needed, such as lecture-style classes, team projects, and four-person consultation and discussion classes, in a way that helped to improve the desirable teaching patterns and learning ability. Second, the place where space was used during the break and the relationship between peers, revealed that most of them were in the classroom and the hallway, and the peer group was composed of three to eight people or more, that were active with various compositions. Third, a gym, library, toilet, stairway, cafeteria, nurse's office, and teachers' room appeared in the center of the building, indicating the need for a balanced layout. Fourth, physical education (dance) rooms, audiovisual rooms (performance rooms), workshops (personal creation), snack bar, rest area, spacious indoor square, and study rooms were needed as facilities that can help learning activities other than current facilities. These outcomes show that the existing classroom layout and space composition formats require some spatial restructuring.

• Journal of Aerospace System Engineering
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• v.15 no.1
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• pp.86-94
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• 2021

PCB-based deployable solar panel is mainly used for CubeSat due to its lightweight and easy of electrical connection. However, as the size of solar panel increases, there is a limit to ensuring the structural safety of solar cells due to excessive dynamic displacement under launch vibration environment. In previous mechanical designs, for the minimization of dynamic deflection, panel stiffness is increased by applying additional stiffeners made of various materials such as aluminum or composite. However, it could have disadvantages for CubeSat design requirements due to limited mass and volumes. In this study, a high-damping 6U solar panel was proposed. It had superior damping characteristic with a multi-layered stiffener laminated with viscoelastic acrylic tapes. Basic characteristics of this solar panel were measured through free-vibration tests. Design effectiveness of the solar panel was validated through qualification-level launch vibration test. Based on test results, vibration characteristics of a typical PCB solar panel and the high-damping laminated solar panel were predicted and a comparative analysis was performed.

• The Journal of Sustainable Design and Educational Environment Research
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• v.20 no.4
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• pp.13-20
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• 2021

In the world, each country is preparing various policies to promote start-ups, and the Korean government is actively promoting policies to support start-ups and the national economy through technology-based start-ups for creating jobs. Recently, the number of start-up companies is on the rise. In particular, in accordance with the industrial structure transformation leading the 4th Industrial Revolution, technology-based start-ups are steadily growing based on knowledge-based services such as information and communication, science and technology service industry, and business support service industry. The purpose of this study is to find out whether the startup space provided by the university reflects the startup-friendly characteristics, and to investigate and analyze the satisfaction and requirements of the space required by the actual college campus startup space users to create a more efficient space configuration plan. Through this study, factors that should be considered first for universities in preparing startup spaces were derived for each space element. Therefore, it is necessary for university campuses to deeply recognize the importance of space provision among the future start-up support systems, and to improve them periodically through the consumers' satisfaction of the space in the construction and improvement of startup spaces.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.6
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• pp.54-63
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• 2022

This paper is a study on the friction damper, which is one of the seismic reinforcement devices for structures. This study developed a damper by replacing the internal friction material with ultra high molecular weight polyethylene (UHMWPE), a type of composite material. In addition, this study applied a multi-friction method in which the internal structure where frictional force is generated is laminated in several layers. To verify the performance of the developed multi-friction damper, this study performed a characteristic analysis test for the basic physical properties, wear characteristics, and disc springs of the material. As a result of the wear test, the mass reduction rate of UHMWPE was 0.003%, which showed the best performance among the friction materials based on composite materials. Regarding the disc spring, this study secured the design basic data from the finite element analysis and experimental test results. Moreover, to confirm the quality stability of the developed multi-friction damper, this study performed an seismic load test on the damping device and the friction force change according to the torque value. The quality performance test result showed a linear frictional force change according to the torque value adjustment. As a result of the seismic load test, the allowable error of the friction damper was less than 15%, which is the standard required by the design standards, so it satisfies the requirements for seismic reinforcement devices.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.239-249
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• 2022

This study attempted to categorize the motivation for participation in leisure sports and analyze the difference in consumer demand for leisure sports wear according to the type. As a result of the analysis, the functionality of the preferred material consisted of movement, comfort, and body temperature maintenance. When purchasing, the factors to consider were extracted such as basic emphasis, emphasis on flaunting, and emphasis on practicality. The improvement requirement was composed of basic function improvement and various function additional factors, and the purchase satisfaction factor was composed of three factors: brand, practicality, design, and functionality. Motives for participation in marine leisure sports were grouped into mania, leisure, and health types. As for the functionality of the preferred material, the mania type and leisure type preferred movement, comfort, and body temperature maintenance functionality over the health type. As for the factors to consider when purchasing, the mania type and leisure type had higher consideration for the factors of basic emphasis, ostentation, and practicality than the health type. In the improvement requirements, both basic function improvement and various function additions had the highest mania type and the lowest health type. In terms of purchase satisfaction factors, practicality and brand were found to have a high leisure type, and functional factors were found to have a high mania type. For the enthusiastic group, it is thought that product development should focus on functionality and additional functions, and health types should be focused on design and utilization.

• Journal of the Korea Society for Simulation
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• v.32 no.3
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• pp.93-108
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• 2023

In manufacturing productivity analysis, understanding the intricate interplay among factors like facility performance, layout design, and workforce allocation within the production line is imperative. This paper introduces a simulation-based methodology tailored to food manufacturing, progressively expanding scenarios to analyze production enhancement. The target system is a food processing plant, encompassing production processes, including warehousing, processing, subdivision, packaging, inspection, loading, and storage. First, we analyze the target system and design a simulation model according to the actual layout arrangement of equipment and workers. Then, we validate the developed model reflecting the real data obtained from the target system, such as the workers' working time and the equipment's processing time. The proposed model aims to identify optimal factor values for productivity gains through incremental scenario comparisons. To this end, three stages of simulation experiments were conducted by extending the equipment and worker models of the subdivision and packaging processes. The simulation experiments have shown that productivity depends on the placement of skilled workers and the performance of the packaging machine. The proposed method in this study will offer combinations of factors for the specific production requirements and support optimal decision-making in the real-world field.

• Korean Journal of Optics and Photonics
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• v.34 no.2
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• pp.53-60
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• 2023

We designed a catadioptric objective lens with a 0.6 numerical aperture (NA) for semiconductor inspection at 193 nm. The objective lens meets major requirements such as a spatial resolution of 200 nm and a field of view (FOV) of 0.15 mm or more. We selected a wavelength of 266 nm for autofocus based on the availability of the light source. First, we built the objective lenses of three lens groups: a focusing lens group, a field-lens group, and an NA conversion group. In particular, the NA conversion group is a group of catadioptric lenses that convert the numerical aperture of the beam focused by the prior groups to the required value, i.e., 0.6. The last design comprises 11 optical elements with root-mean-squared (RMS) wavefront aberrations less than λ/80 over the entire field of view. We also achieved the athermalization of the objective lens with focus-shift alone satisfying the performance of RMS wavefront aberration below λ/30 at a temperature range of 20 ± 1.2 ℃.