• KIPS Transactions on Computer and Communication Systems
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• v.11 no.5
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• pp.147-156
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• 2022

Industrial control systems that manage and maintain various industries were mainly operated in closed environment without external connection, but with the recent development of the Internet and the introduction of ICT technology, the access to the industrial control system of external or attackers has become easier. Such incorrect approaches or attacks can undermine the availability, a major attribute of the industrial control system, and violation of availability can cause great damage. In this paper, when issuing commands in an industrial control system, a verification group is formed using a random list to verify and execute commands, and a trust score technique is introduced that applies feedback to the verification group that conducted verification using the command execution result. This technique can reduce overhead generated by random generation in the process of requesting command verification, give flexibility to the verification process, and ensure system availability. For the performance analysis of the system, we measured the time and gas usage when deploying a smart contract, gas usage when verifying a command. As a result, we confirmed that although the proposed system generates a random list compared to the legacy system, there was little difference in the time when it took to deploy smart contract and that the gas used to deploy smart contract increased by about 1.4 times in the process of generating a random list. However, the proposed system does not perform random operations even though the operation of command verification and confidence score technique is performed together during the command verification process, thus it uses about 9% less gas per verification, which ensures availability in the verification process.

• The Korean Journal of Food And Nutrition
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• v.29 no.3
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• pp.363-370
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• 2016

The purpose of this study is to investigate the dietary life status according to smart device use among university students. In 2015, data was collected during a 3 month survey of the eating behaviors, lifestyles, eating habits, and use of smart devices of 550 university students, as well as their dependency on smartphones. Ultimately, 520 subjects (94.5% analysis rate) were divided into three groups based on their daily use time of smart device: low-use group (<4.7 hours, n=173), medium-use group (${\geq}4.7hours$ and <6.4 hours, n=174), and high-use group (${\geq}6.4hours$, n=173). The more frequent use groups showed a higher level of dependency on the smartphone. Breakfast was found to be the most commonly skipped meal; and the high-use group showed a higher response of irregular meals than low-use group. In assessment of eating habits, the subjects with less smart device usage ate more regularly and at fixed times, did not overeat, drank milk everyday, and did not consume processed food as often. To sum up, more irregularity of meal and undesirable eating habits were found among university students with higher use of smart devices. These results suggest that a control of smart device usage would lead to a more desirable dietary life in university students.

• Journal of Digital Convergence
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• v.13 no.6
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• pp.29-37
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• 2015

Entering the convergence education era, the emergence of smart devices removed the constraint of time and space for study, so if we use smart devices appropriately for education, it will strengthen students' abilities and cultivate creative human resource. Therefore the current study analyzed the general application condition of the smart devices through surveys targeted to students and proposed a measure in applying the smart device as an educational information. In relation to information application, a test was proceeded after carrying out education targeted to experiment group students by naming the group information search, communication, cooperation, sharing, report generation, data storage, online assessment and project management activity. Through the test and survey analysis, it was discovered that the experiment group students displayed higher self-efficacy and ability in applying the smart device as information compared to the control group.

• Journal of Practical Engineering Education
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• v.16 no.1_spc
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• pp.1-9
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• 2024

The introduction of smart factory digital twins is a concept that has already been proposed to increase productivity in the manufacturing industry through CPS(Cyber Physics System), and has been applied to specific industrial process stages or partially introduced in stages where simulation is required. However, with the recent development of the 4th Industrial Revolution technology, it is receiving attention again along with XR (Extended Reality) technology. However, because there are not many effective cases, this study analyzed the devices, equipment, and technology of the manufacturing process to build a digital twin applying digital threads and synchronized signals and information to control, remote control, and produce intelligent process automation equipment. A platform capable of analyzing information was proposed and developed. Through this, we designed and built an XR content service platform that can support artificial intelligence and developed it to enable control, remote control, and analysis of production information. A possible platform was proposed and developed. We hope that this study will be helpful in conducting research on many cases, and in the future, expanded research on increasing productivity in each part of the process and production is needed through intelligent models.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.261-269
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• 2012

Objective: The aim of this study is to develop an analysis method to extract plausible types of errors when using a smart mobile in nuclear power plants. Background: Smart mobiles such as a smart-phone and a tablet computer(smart-pad) are to be introduced to the various industries. Nuclear power plant like APR1400 already adopted many up-to-date digital devices within its main control room. With this trend, various types of smart mobiles will be inevitably introduced to the nuclear field in the near future. However nuclear power plants(NPPs) should be managed considering a big risk as a result of the trend not only economically but also socially compared to the other industrial systems. It is formally required to make sure to reasonably prevent the all hazards due to the introduction of new technologies and devices before the application to the specific tasks in nuclear power plants. Method: We define interaction segments(IS) as a main architect of interaction description, and enumerate all plausible error segments(ES) for a part of design evaluation of digital devices. Results: We identify various types of interaction errors which are coped with reasonably by interaction design using smart mobiles. Conclusion: According to the application result of the proposed method, we conclude that the proposed method can be utilized to specify the requirements to the human error hazards in digital devices, and to conduct a human factors review during the design of digital devices. Application: The proposed method can be applied to predict the human errors of the tasks related to the digital devices; therefore we can ensure the safety to apply the digital devices to be introduced to NPPs.

• Journal of the Korea Society of Computer and Information
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• v.25 no.7
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• pp.143-150
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• 2020

Recently, many companies are interested in smart factory services. Because various smart factory services are provided by the combination of mobile devices, cloud computing, and IoT services. However, many workers turn away from these systems because most of them are not implemented from the worker's point of view. To solve this, we implemented a development tool that allows field workers to produce their own services so that workers can easily create smart factory services. Manufacturing data is collected in real time from sensors which are connected to manufacturing facilities and stored within smart factory platforms. Implemented development tools can produce services such as monitoring, processing, analysis, and control of manufacturing data in drag-and-drop. The implemented system is effective for small manufacturing companies because of their environment: making various services quickly according to the company's purpose. In addition, it is assumed that this also will help workers' improve operation skills on running smart factories and fostering smart factory capable personnel.

• Smart Structures and Systems
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• v.3 no.1
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• pp.89-114
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• 2007

Two aspects of the design of a small-scale smart wing are addressed in this work, related to the ability of the wing to modify its cross section assuming the shape of two different airfoils and to the possibility of deflecting the profiles near the trailing edge in order to obtain hingeless control surfaces. The actuation is provided by one-way shape memory alloy wires eventually coupled to springs, Shape Memory Alloys (SMAs) being among the most promising materials for this kind of applications. The points to be actuated along the profiles and the displacements to be imposed are selecetd so that they satisfactorily approximate the change from an airfoil to the other and to result in an adequate deflection of the control surface; the actuators and their performances are designed so that an adequate wing stiffness is guaranteed, in order to prevent excessive deformations and undesired airfoil shape variations due to aerodynamic loads. The effect of the pressure distributions, calculated by way of the XFOIL software, and of the actuators loads, is estimated by FE analyses of the loaded wing. Two prototypes are then realised incorporating the variable airfoil and the hingeless aileron features respectively, and the verification of their shapes in both the actuated and non-actuated states, supported by image analysis techniques, confirms that interesting results are achievable with the proposed lay out and design considerations.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.177-182
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• 2015

Nevertheless 3D printer is propagated fast, it is difficult for us of using 3D printer at the same time because of 3D printer's slow velocity. Existing solution is to print using SD card which moves files and on PC but this method is spend too much time and can not be showed status of printing. Yet we have no 3D printer software solution which is controlled and printed remotely. Therefore, this 3D printer software solution makes 3D printer be connected on internet networks and selected to use it on smart App. And it is controlled and printed remotely. In my paper, to build an Android App. which can execute these functions, an effective analysis & design using UML and implementation method will be presented.

• Physical Therapy Rehabilitation Science
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• v.10 no.2
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• pp.217-224
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• 2021

Objective: This study is about the physical therapy facilities and environmental and service satisfaction of patients visiting in the front military hospitals and divisions. Design: Survey study Methods: Prior to this survey, 28 users of the front division and military hospital were surveyed in advance to verify the survey through reliability analysis. For this survey, 1,300 questionnaires were distributed to seven frontline divisions and three military hospitals, of which 578 military hospitals and 479 divisions were collected. Among them, 1,042 pieces of data were used for the analysis, excluding 15 questionnaires that exceeded the research period of the division. Analysis methods used Cronbach-α and multiple regression for mean comparison analysis, factor analysis for validation, and reliability verification to verify differences between groups. Results: As a result of the satisfaction analysis, the division's stage satisfaction was higher than that of military hospitals, and as a result of analyzing the satisfaction items by sector, accessibility, re-visit doctors, and professionalism accounted for a large portion in the field of physical therapy services. As a result of a regression analysis, the factors that affect the satisfaction of physical therapy had the greatest impact on facility and environmental satisfaction, and expertise in physical therapy services. Conclusions: In the future, it will be necessary to improve the comfort of the physical therapy room and the expertise of physical therapy in order to improve the satisfaction level of physical therapy at military medical facilities.

• International journal of advanced smart convergence
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• v.4 no.2
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• pp.14-19
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• 2015

Recently, water sewage disposal facilities are able to manage real-time data collection and record management through compact broadband modem LAN switching technology. Therefore, it needs more stable and efficient facility management. So, we required practical use of environmental facilities convergence based on broadband integrated modem. In this paper, we proposed short distance wireless communication network of compact broadband modem for sewage disposal facilities. And it received data inside of water treatment facility using the two communication methods (IEEE802.11x and IEEE802.15.4x). Then, our proposed an data-flow control algorithm of wireless network technology will prioritize processing data when emergency happen through collecting data, analysis data and processing. Lastly, we proved usefulness by experiment and simulation analysis.