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pISSN : 1598-849X / eISSN : 2383-9945

2020 KCI Impact Factor : 0.4
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2018, Vol.23, No.2

  • 1.

    A Study on Stability Improvement of High Energy Laser Beam Wavefront Correction System

    JongKyu Jung | Sooman Lee | 2018, 23(2) | pp.1~7 | number of Cited : 0
    Abstract PDF
    The adaptive optics for compensating for optical wavefront distortion due to atmospheric turbulence has recently been used in systems that improve beam quality by eliminating the aberrations of high power laser beam wavefront. However, unseen-mode, which can not be measured in the wavefront sensor, increases the instability of the laser beam wavefront compensator on the adaptive optics system. As a method for improving such instability, a mathematical method for limiting the number of singular values is used when generating the command matrix involved in generation of the drive command of the wavefront compensator. In the past, however, we have relied solely on experimental methods to determine the limiting range of the singular values. In this paper, we propose a criterion for determining the limiting range of the singular values using the driving characteristics and the correlation technique of the wavefront compensator's actuators and have proved its performance experimentally.
  • 2.

    A New Exploratory Testing Method for Improving the Effective IP Set-Top Box Test

    Donghyun Kim | Kim, yoon | 2018, 23(2) | pp.9~16 | number of Cited : 1
    Abstract PDF
    Recently, as various IP set-top boxes based on Android OS have been widely used in general households and public facilities, complaints about services and set-top boxes have continued to increase as much as other smart devices. In order to reduce this problem, the manufacturer performs the testing work before the product is commercialized. However, the testing can reduce potential defects in the product, but it can not prove that the product is free of defects. Therefore, the quality of the product can vary depending on how effective testing techniques are introduced. In this paper, we propose a new exploratory testing method that minimizes test case creation time and makes it easier to plan and execute test while simultaneously learning how to run the product under test. Using the first proposed method, the test time is reduced by about 16.7 hours and the defect detection rate is 25.4% higher than the formal specification-based testing method. Informally, the test time was shortened by about 4.7 hours and the defect detection rate was 13% higher than the informal experience-based testing method.
  • 3.

    Gait Type Classification Using Pressure Sensor of Smart Insole

    Woo-Duk Seo | LEESUNGSIN | Won-Yong Shin and 1other persons | 2018, 23(2) | pp.17~26 | number of Cited : 2
    Abstract PDF
    In this paper, we propose a gait type classification method based on pressure sensor which reflects various terrain and velocity variations. In order to obtain stable gait classification performance, we divide the whole gait data into several steps by detecting the swing phase, and normalize each step. Then, we extract robust features for both topographic variation and speed variation by using the Null-LDA(Null-Space Linear Discriminant Analysis) method. The experimental results show that the proposed method gives a good performance of gait type classification even though there is a change in the gait velocity and the terrain.
  • 4.

    Development of Analog Gauge Recognition System Using Morphological Operation and Periodic Measurement Function

    Jin-Kyu Tyu | Kwak Young Tae | 2018, 23(2) | pp.27~34 | number of Cited : 0
    Abstract PDF
    In this paper, we propose a new method to read the hand of analog gauges to prepare for the smart factory. In addition, we suggest a new and improved method that can apply, in general, diverse analog gauges even if their scale types and ranges are various. Many companies are making great efforts to build smart factories that increase energy efficiency and automation. Managers use a variety of equipment and tools to manage the production process at the factory. In this kind of factory, analog gauges have been often used with many equipment and tools. Analog gauges are mostly circular in shape, and most papers use circular hough transform to find the center and radius of a circle. However, when the object to be found is not of the correct circle type, it takes a long time to recognize the circle using the circular hough transform, and the center and radius of the circle can not be calculated accurately. The proposed method was tested on various circular analog gauges. As a result, we confirmed that our method is outstanding.
  • 5.

    A Grid-based Efficient Routing Protocol for a Mobile Sink in Wireless Sensor Networks

    Lee, Taekkyeun | 2018, 23(2) | pp.35~43 | number of Cited : 0
    Abstract PDF
    In this paper, we propose a grid-based efficient routing protocol for a mobile sink in wireless sensor networks. In the proposed protocol, the network is partitioned into grids and each grid has a grid head. For the efficient routing to a mobile sink, the proposed protocol uses a mobile sink representative node to send the data to a mobile sink and grid heads are used as a mobile sink representative node. Furthermore, the proposed protocol uses nodes in the boundary of the center grid as position storage nodes. The position storage nodes store the position of a mobile sink representative node and provide source nodes with it for data delivery. With these features, the proposed protocol can reduce a lot of overhead to update the position information and improve the delay of data delivery to a mobile sink. The proposed protocol performs better than other protocols in terms of the delay and the energy consumption per node in the performance evaluation.
  • 6.

    Small size IoT Device Monitoring System Modeling applying DEVS methodology

    Se-Han Lee | Hee-Suk Seo | Choi Yo Han | 2018, 23(2) | pp.45~51 | number of Cited : 0
    Abstract PDF
    In this paper, we propose a Designed and Developed home router management system. Through the fourth industrial revolution and development of IoT technology, now people can experience a wide range of IoT related services at their workplace or daily lives. At the industrial site, IoT devices are used to improve productivity such as factory automation, and at home, IoT technology is used to control home appliances from a remote distance. Usually IoT device is integrated and controlled by the router. Home router connects different IoT devices together at home, however when security issues arise, it can invade personal privacy. Even though these threats exist, the perception for home router security is still insufficient. In this paper, we have designed and developed home router management system using DEVS methodology to promote the safe use of home router. Through the DEVS methodology, we have designed the system and developed the mobile application. This management system enables users to set up security options for home router easily.
  • 7.

    An Efficient Group Key Agreement Using Hierarchical Key Tree in Mobile Environment

    Seokhyang Cho | 2018, 23(2) | pp.53~61 | number of Cited : 1
    Abstract PDF
    In this paper, the author proposes an efficient group key agreement scheme in a mobile environment where group members frequently join and leave. This protocol consists of basic protocols and general ones and is expected to be suitable for communications between a mobile device with limited computing capability and a key distributing center (or base station) with sufficient computing capability. Compared with other schemes, the performance of the proposed protocol is a bit more efficient in the aspects of the overall cost for both communication and computation where the computational efficiency of the scheme is achieved by using exclusive or operations and a one-way hash function. Also, in the aspect of security, it guarantees both forward and backward secrecy based on the computational Diffie-Hellman (CDH) assumption so that secure group communication can be made possible. Furthermore, the author proves its security against a passive adversary in the random oracle model.
  • 8.

    Smart Safety Belt for High Rise Worker at Industrial Field

    SeHoon Lee | Hyo-Jae Moon | Jin-Hyun Tak | 2018, 23(2) | pp.63~70 | number of Cited : 0
    Abstract PDF
    Safety management agent manages the risk behavior of the worker with the naked eye, but there is a real difficulty for one the agent to manage all the workers. In this paper, IoT device is attached to a harness safety belt that a worker wears to solve this problem, and behavior data is upload to the cloud in real time. We analyze the upload data through the deep learning and analyze the risk behavior of the worker. When the analysis result is judged to be dangerous behavior, we designed and implemented a system that informs the manager through monitoring application. In order to confirm that the risk behavior analysis through the deep learning is normally performed, the data values of 4 behaviors (walking, running, standing and sitting) were collected from IMU sensor for 60 minutes and learned through Tensorflow, Inception model. In order to verify the accuracy of the proposed system, we conducted inference experiments five times for each of the four behaviors, and confirmed the accuracy of the inference result to be 96.0%.
  • 9.

    The study on improving concept design of 119 paramedic helmet in Korea

    Shin, Dong-min | CHO,BYUNGJUN | 2018, 23(2) | pp.71~75 | number of Cited : 0
    Abstract PDF
    In this paper, we propose an optimized size for paramedic helmets as personal safety equipment for emergency medical technician. This identified priorities for advanced loT technologies that need to be attached to paramedic Helmets. Paramedic helmets with advanced technology have been developed others, but they have not been developed for Korea. The products of kinds do not exist in Korea. Based on the average size of Korean men’s heads, this derived an optimized size for paramedic helmets. The optical width of this product would be 205 mm. The length would be 265 mm. The height would be 155 mm. The verified that this size meets the requirements of the authorizing certification institution. What paramedic most need in helmets is various kinds of functionality. The communication and information transmission features. In this study, many personal safety equipment for paramedics, including the extraction of an optimal size of strong emergency head-protection helmets to protect the head of the human body on helmets based on an design. We anticipate this result to be a basis for developing an even more sophisticated and functional paramedic helmet than those that currently exist
  • 10.

    A study on the image design PBL class that can be used for e-Digital contents production

    Insoo Ahn | 2018, 23(2) | pp.77~82 | number of Cited : 0
    Abstract PDF
    In this paper, we propose an improvement plan to increase the learning effect and satisfaction through the PBL - related video design class. PBL To prepare for the Fourth Industrial Revolution era, we must acquire diverse knowledge and skills to discover problems and solve them creatively. Therefore, various learning methods are being studied, and one of them is PBL learning. PBL is a learner-centered education that explores problems that may arise from specific topics other than existing curriculum-based education methods and finds solutions to problems. In this study, two lectures on video design related to video contents and image contents were taught in PBL class, and PBL class problem was analyzed and the improvement plan was studied.
  • 11.

    Mediating Effects of Resilience on the Relationship between Smartphone Addiction and Anger Coping Strategies - Focusing on the comparison of students of general high schools and special purpose high schools -

    kim youn hwa | 2018, 23(2) | pp.83~91 | number of Cited : 2
    Abstract PDF
    In this paper, we verify the mediating effects of resilience on the relationship between smartphone addition and anger coping strategies, focusing on 299 high school students, and examine the effect of variables on students of general high schools and special purpose high schools. We found that smartphone addiction affects students’ resilience and the resilience affects their anger-out and anger-in. It is also found that resilience has mediating effects on the relationship between students’ smartphone addiction and anger coping strategies. As for students of general high schools, their smartphone addiction has positive effects on anger-out and anger-in while that of students of special purpose high schools affects their resilience, and the resilience affect their anger-out and anger-in. The results suggest that a high-level of smartphone addiction tends to reduce resilience, which lowers anger moderation, and stress the need of intervention by school type. Finally, this paper discusses implications based on its results and importance of further studies.
  • 12.

    The Effect of Hospital Administrative Staff’s Positive Psychological Capital on Psychological Well-being

    Young-Ju Jeun | Jeong-Sun Kim | 2018, 23(2) | pp.93~98 | number of Cited : 2
    Abstract PDF
    This study analyzed the causal relationship between positive psychological capital and psychological well-being of hospital administrative staff among the medical institution workers who were hard to find in previous studies. The purpose of this study is to suggest the policy implications to improve the psychological well-being level of the hospital administrative staff through the analysis results. For the empirical analysis of variables, self-efficacy, hope, optimism, and resilience were selected as the independent variables. Selfacceptance, positive relations with others and autonomy were selected as dependent variables. The results of empirical analysis showed that there is a significant relationship between the variables and theoretical and policy implications were suggested based on these results.
  • 13.

    Development of technology to improve information accessibility of information vulnerable class using crawling & clipping

    JEONG SEONG BAE | Kyung-Shin Kim | 2018, 23(2) | pp.99~107 | number of Cited : 1
    Abstract PDF
    This study started from the public interest purpose to help accessibility for the information acquisition of the vulnerable groups due to visual difficulties such as the elderly and the visually impaired. In this study, the server resources are minimized and implemented in most of the user smart phones. In addition, we implement a method to gather necessary information by collecting only pattern information by utilizing crawl & clipping without having to visit the site of the information of the various sites having the data necessary for the user, and to have it in the server. Especially, we applied the TTS(Text-To-Speech) service composed of smart phone apps and tried to develop a unified customized information collection service based on voice-based information collection method.
  • 14.

    A Factor Analysis on Tourism Satisfaction through Expected Effects on Tourism Resources Development and Tourism Development Policy

    Rack-In Choi | 2018, 23(2) | pp.109~116 | number of Cited : 0
    Abstract PDF
    By November 2017, the number of overseas travelers of the Korean nationals reached a cumulative total of 2,409,155, bringing about 26 million overseas travelers. For Korea's future growth and development, it is necessary to make the country much more attractive than now, and to enhance the competitiveness of the domestic tourism field and attract the people of the world. The purpose of this study is to analyze the satisfaction of tourism policy and to utilize it in the development of tourism policy through the empirical analysis of the satisfaction of the tourism resource development and the tourism development policy in Korea. The policy that can achieve the policy purpose pursued by the regional tourism resource development and the future regional tourism resource development and development policy plan were suggested. It is necessary to consider factors related to development of tourism resources such as policy factors, development factors, management factors, and environmental factors. Local tourism development policies should be made considering the factors related to tourism policy expectation, regional characteristics, cultural characteristics and environmental characteristics. In addition, the global competitiveness of the tourism industry and enterprises should be strengthened through the protection of companies and rationalization of tourism related regulations in relation to the opening and expansion of the global tourism market scale.
  • 15.

    On the Relationship between College Students’ Attitude toward the Internet and their Self-directed English Learning Ability

    Park, Kab Yong | Tae-Soo Sung | Chi-woon Joo | 2018, 23(2) | pp.117~123 | number of Cited : 1
    Abstract PDF
    This article is to investigate the possibility that project-based classes introducing mobile phones can replace the monotony of traditional classes led by teachers as well as they can encourage students to take active part in the classes to some extent. The students in groups choose a genre for their own video projects (e.g., movie, drama, news, documentary, and commercial) and produce the video contents using a mobile phone for presentation made at the end of a semester. In the sense that the students are allowed to do video-based mobile phone projects, they can work independently outside of class, where time and space are more flexible and students are free from the anxiety of speaking or acting in front of an audience. A mobile phone project consists of around five stages done both in and outside of the classroom. All of these stages can be graded independently, including genre selection, drafting of scripts, peer review and revision, rehearsals, and presentation of the video. Feedback is given to students. After the presentation, students filled out a survey questionnaire sheet devised to analyze students’ responses toward preferences and level of difficulty of the project activity. Finally, proposals are made for introduction of a better mobile phone-based project classes.