Korean | English

pISSN : 1975-7700 / eISSN : 2734-0570

2020 KCI Impact Factor : 0.42
Home > Explore Content > All Issues > Article List

2019, Vol.14, No.5

  • 1.

    A Haptic Controller Based on Smart Actuators for Mobile Virtual Environment

    Seok-Han Lee | Choi Dong-Soo | Hyesun Lee and 1other persons | 2019, 14(5) | pp.435~444 | number of Cited : 0
    Abstract PDF
    In this paper, we propose a handheld haptic controller that conveys kinesthetic sensation to users. The haptic controller consists of two haptic buttons based on the smart actuators and thin pressure sensors. The smart actuator is composed of an electromagnet and a soft magnetorheological elastomer whose stiffness can be changed by the external magnetic strength and flux. If voltage input is applied to the electromagnet, the magnet generates the magnetic fields to make the magnetorheological elastomer stiff. The amount of stiffness depends on the amplitude of the voltage input. Therefore, the smart actuator can simulate the stiffness of a target object. Furthermore, when the AC signal is provided to the electromagnet, the magnetorheological elastomer generates mechanical vibration. We construct a mobile virtual application whose goal is to move a bird to another place without colliding obstacles. Two buttons in the haptic controller are mapped as the soaring and the shooting an item, respectively. If a user does not push the soaring button, the bird falls toward the ground because it is affected by gravity. In case of pressing the soaring button, the bird that is in the application soars up. At that time, we can control the stiffness of the haptic button according to simulate various virtual environments (Blue sky, Snowstorm, and Underwater). Furthermore, when the user press shooting button, the haptic button generate vibration to make user feel shooting an item. We conducted the user study to evaluate the proposed haptic system. The result of the user study shows that the proposed haptic controller can improve the user’s enjoyment, immersion, and operability in the mobile virtual environment than the general controller without haptic feedback. We expect that the proposed haptic system is widely applied to various virtual reality applications such as virtual education/training and military or medical simulators.
  • 2.

    A Study on the Enterprise's Big Data Utilization

    Kim, Kwang-hyun | Yu-Jung KIM | 2019, 14(5) | pp.445~453 | number of Cited : 5
    Abstract PDF
    This paper describes the new elements of big data that have emerged in the modern era and then states the importance of big data through utilization and examples. With customers' needs and value diversified and rapidly changing, companies are increasingly required to analyze information and data needed by businesses through real-time vast amounts of data generated by them and use it throughout their business operations, and with the development of IT technology and the 4th industrial revolution, the era of big data has begun in which companies acquire and analyze information and obtain information needed by companies at a cost that is easier and less than before. In the modern society, companies have transformed into an era where they cannot survive without the existence of data, and each company continues its efforts to develop through big data, gaining customers' attention and increasing loyal customers through its own programs and marketing strategies to meet each discipline. For example, Amazon's Anticipate sipping, Amazon's Web service, the Mystique System of the Ritz-Carlton Hotel, and Wal-Mart Lab, which highlights how and the importance of using big data worldwide, should be studied to present the corporate strategies and directions that Korean companies with weaknesses should perform in the use of big data, and make efforts to enhance competitiveness of each company and survive in corporate competition through cooperation with the government.
  • 3.

    Color Reproduction Techniques Based on Color Harmonized Pattern of Reference Image

    Won-Yong Lee | 2019, 14(5) | pp.455~462 | number of Cited : 0
    Abstract PDF
    A color reproduction technique is a study in which the color information of the reference image is expressed in the input image. Previous studies makes natural color transferred results by allowing the input image to have a distribution of colors with reference images. However, if reference images are used with works by famous artists, their characteristics are not properly expressed. This is because works by famous artists use limited colors, and color harmonized pattern. In this study, we propose novel color reproduction techniques which use artist's work as a reference image and reflects the characteristics of the reference image. Our algorithm consists of two stages. The first step is the reference image analysis phase. For this purpose, the representative colors used in the reference images were extracted using K-means clustering algorithms. And the color harmonization patterns that the work has were analyzed by analyzing what forms are composed between the representative colors of the reference image. The second stage is the color transfer phase using the analysis information. For this, we use image saliency algorithm to extract the most focusing color of the input image. Image saliency is a study that extracts the most visible areas of the image, making it the most visible color of the input images viewed by the area with the highest visibility. The rest of the region applied the color harmonization pattern of the reference image. Our algorithm can easily generate result images that express the color harminized pattern effects of works used as reference images.
  • 4.

    A Study of the Oil Support System Outcome Influenced by Alterations of Oil Supply System and Oil Supply Pump Performance Improvements - Focusing on Army Mechanized Troops

    Se-Ho Lee | Kim Ryong | Kyung-Hye Park | 2019, 14(5) | pp.463~477 | number of Cited : 0
    Abstract PDF
    According to the Army basic plan related to Defence reform, the operational area of the future Army Corps will be expanded and some assigned combat equipment will be modified. Owing to those changes, the operational sustainment support plan would be influence by assigned equipment for future mechanized troops. Accordingly, it is vital to verify the future oil supply system which is one of the most important factor in the operational sustainment support. The purpose of this study is to investigate the change of tank lorry supply time and waiting time influence by the 10~200% improvement of oil supply pump and to suggest the target value of the oil supply pump performance. Judging by simulation result, 10,000 liter is suggested to tank lorry capacity of the tank battalion. 4,500 liter is of the field artillery battalion. it is derived from the modeling of the future mechanized battalion level. Second, oil release time is 44~75% of total supply time. So it can be posed that one of the most important factor in the oil supply time is the release performance of the oil pump. Simulating with the improved release performance of oil pump, it is significant up to 100%. But it is meaningless the range over 100%. Third, the total oil supply time is reduced by 10.4~24.5% point. In conclusion, it is proved that the oil supply system performance could be improved by reducing oil release time of tank lorry, vehicle waiting time and concurrent running time. All reducing time is due to the performance improvement of oil pump.
  • 5.

    Remote Mutual Authentication Scheme for Anonymity and Un_Traceability Based on Biometric Information Using Public Key Cryptography

    shin kwang cheul | 2019, 14(5) | pp.479~489 | number of Cited : 0
    Abstract PDF
    The growth of Internet technology is providing high quality contents for users to access conveniently. It has been a growing number of application servers to provide services to users. These services are provided through insecure public channels. It is vulnerable to blocking, modification and deletion of transmission information by third parties. Therefore, a mutual authentication mechanism is required to securely communicate between the user and the server. Mechanism is a way for a user to access a remote application server to establish mutual authentication and session key with the server. It is used to combine biometrics and passwords to enhance the security of the authentication scheme. In many studies, authentication schemes have designed the protocol to resist threats by using the characteristics and advantages of hashing bio, public key and secret key cryptography. However, it can be seen that most proposed authentication schemes had limitations in designing perfect security. This paper briefly reviews the proposed schemes. In addition, the proposed scheme prevents the exposure of anonymous and traces in the authentication process and solves the problem of user/server impersonation attack. To improve the scheme, we propose a hashing bio-based authentication and key agreement scheme in a single server using public key cryptography.
  • 6.

    A Concept Mapping Analysis of the Effects of Mind-Subtraction Meditation, Using MDS(Multimensional Scaling) and HCA(Hierarchical Cluster Analysis) Techniques

    Shin, Namin | 2019, 14(5) | pp.491~501 | number of Cited : 1
    Abstract PDF
    This study conducted a concept mapping analysis in order to find out the effects of Mind-Subtraction Meditation practiced by 19 middle school students as part of a school-based meditation program. The program was carried out for 17 weeks, twice a week with each session lasting 45 minutes, under the guidance of two trained meditation teachers. For the purpose of the research, the six steps of concept mapping process proposed by Trochim were employed. Two rounds of data collection were carried out. First, the students were solicited to write about the effects of the Mind-Subtraction Meditation, and 61 statements were generated as a result of the first survey. Second, the students were asked to rate the importance of each statements generated by themselves while categorizing each statements. These data were analyzed by SPSS using Multimensional Scaling(MDS) technique. The MDS analysis showed a visual point in which each statement was located in two dimensional graph and Hierarchical Cluster Analysis(HCA) helped to determine the number of cluster of the statements. The HCA resulted in four clusters as the effects of Mind-Subtraction Meditation. The four clusters were labelled as the improvement of self-reflection(inner growth), of interpersonal relationships(friends, family), of attitude towards class(concentration, diligence) and of positive affect(diminishing stress and anger). The implications of the results were discussed along with the potential of the concept mapping as a research methodology useful in capturing subjective perceptions or phenomena in a systematic way.
  • 7.

    Development of an Assesment Scale of Preschool Mothers' Happiness by Factor Analysis and Internal Consistency Reliability

    Ryu,Chill-Sun | Hye Jung Park | Yu-Kyeong Choi | 2019, 14(5) | pp.503~513 | number of Cited : 0
    Abstract PDF
    The purpose of this study was to develop a systemic, useful assessment scale to evaluate the preschool mothers' happiness. The subjects of this study were 489 preschool mothers in D city and S city. They were randomly chosen. A survey was performed from October, 2018 to January, 2019. Construct validity and reliability of the survey were evaluated by factor analysis and coefficient of internal consistency. To clarify factor analysis, varimax rotation was applied. The results and further analysis revealed 6 factors for happiness of mothers of preschoolers: 1) familial relationship; feeling happiness through family including children, 2) absolute satisfaction; relying on religion and trusting God, 3) positive attitude; recognizing one’s sociocultural environment positively, 4) reciprocal interaction; intimate relationship with people around them, 5) inner desire; emphasizing happiness through one’s ‘own’ life and joy, 6) self-improvement; effort to improve one’s potential and capacity. The Cronbach’s Coefficient Alpha value of this assessment scale comprised of 37 questions was .943, a sufficiently high value. As a result, assessment scale of preschool mothers' happiness involving Korea's unique sociocultural phenomena was developed. Researches for evaluation of mothers' happiness and multi-cultural studies with this assessment scale will be required for further studies.
  • 8.

    A Performance Evaluation Analysis of Product Recommendation Techniques

    Kim Chul Jin | Jeong, JiHyun | Cheon-Woo Jo and 1other persons | 2019, 14(5) | pp.515~525 | number of Cited : 2
    Abstract PDF
    In the vast product information of the e-commerce, the user needs a lot of effort to find the required product, and the seller may affect the sales if the product is not provided quickly to the user. Accordingly, the e-commerce company provides a recommendation service based on the user's past purchase information so that the user can provide a product required by the user. The recommendation techniques for providing recommendation services include a collaborative filtering recommendation technique that derives recommendation information through a relationship between users or products and a recommendation technique that utilizes a deep learning technology based on machine learning. In this paper, we study user-based collaborative filtering recommendation and item-based collaborative filtering recommendation as collaborative filtering recommendation techniques, and RNN, LSTM, and Word2Vec recommendation techniques as deep recommendation techniques. In this paper, we evaluate the recommendation performance based on the e-commerce purchase information for these recommendation techniques. As a metric for evaluating the recommendation performance, it analyzes the recommendation performance using accuracy, recall, and F1 measure. The results of the validation of the recommendation performance showed that the LSTM recommendation technique had the best recommendation performance, and that the recommendation performance was the best when the number of recommendations was Top-10. Based on the recommended performance evaluation procedure and evaluation results proposed in this study, it can be referred to when analyzing the performance of recommendations in various fields.
  • 9.

    A Low-complexity Time-domain SNR Estimation Algorithm for OFDM Communication Systems

    Jihun Koo | YOONHAYOUNG | 2019, 14(5) | pp.527~534 | number of Cited : 1
    Abstract PDF
    Orthogonal Frequency Division Multiplexing technology is a multi-carrier modulation technique that uses multiple narrowband subcarriers for high speed data transmission, wherein each subcarrier carrying corresponding data bit, among which are orthogonal to each other. Because of its strong resistance to frequency selective fading, it is indispensable for broadband digital communication systems such as 4G and 5G, and wireless local area networks. However, since the unified symbol detector and channel estimation suitable for all channel environments are difficult in practical cases, algorithms using estimated SNR are used in each block of the communication system. Therefore, SNR estimation accuracy has become a major performance factor in an important OFDM wireless communication system. In this paper, we propose a simplified method of time-domain based SNR estimation based on the representative IEEE802.11 standard among OFDM communication systems. The proposed method is approximated based on time-domain SNR estimation, presented as a simple implementation without square or division, and its performance is shown by simulation. Compared with the time-domain SNR estimation without approximation, it shows low and constant errors of about 0.5 dB and 0.2 dB in the frequency fading channel environment of AWGN and channel model D, respectively. And, it is shown that the proposed method can be effectively used compared to the existing approximation method in the low SNR region that influences the performance of the communication system.
  • 10.

    A Study on Machine Learning-based Grass Demand Forecasting

    wan-sik an | 2019, 14(5) | pp.535~542 | number of Cited : 0
    Abstract PDF
    The origin of the grass varies between regions and countries, but in the West, crops, which have been widely used for feed, have long been adapted to livestock grazing, and are derived from plants and perennials with good land cover capacity. In Korea, the origin of grass is different from that of the West. It has been used to decorate and cover the tomb's ground. Thus, Grass is one of the essential elements in our life. Grass is the major resource of various ecosystems and it also provides a space to relax. Nevertheless, Recently, Korea is recognized as a recession due to the reduction of new golf course construction and the slowdown of construction industry. However, since the 5-day system was implemented due to economic development and national income improvement after the Olympic and World Cup, the demand for grass as a green space for recreation and sports Is increasing. In particular, the use of new towns, the West Coast Saemangeum project, neighborhood parks, school grounds, and general residential gardens is increasing. Grass is expected to increase the value added of social indirect capital such as highways, the increase of golf population, the greening of urban and national lands using grass such as the increase of recreational activities and urban grass parks. In addition, the grass industry is a comprehensive field that includes the development, production, composition and management of garden, slope and sports. However, the grass industry is limited to production. This situation is lacking, and there is also a lack of basic data on the system or industry that can support the grass industry. Accordingly, we are necessary to have a research how we improve to use of grass and suggest newly methods with water demand.
  • 11.

    A Study of an Intelligent Studying Abroad Matching Platform Based on Bigdata

    Jin-Il Kim | 2019, 14(5) | pp.543~552 | number of Cited : 0
    Abstract PDF
    Recently, Asian market for studying abroad is becoming activated. In particular, the number of international students that want to study in Korea is increasing due to the influence of the Korean Wave. International students are changing to the trend of searching for a personalized service that is suitable for them, and they want to receive not only college entrance information but also various information such as information necessary for studying abroad and career information after studying abroad. Now, the Korean study information system provides general information about studying in Korea, including online application, comprehensive study guidebook, college information guide and scholarship system. But it does not provide enough information or convenience for international students. Therefore, international students are provided with the college information they want, and the college solves the problem of attracting and interpreting international students. The guide for studying aborad is at a time when it is necessary to provide customized information to international students and colleges to provide services to each other. In this paper, we design an intelligent studying aboard matching platform based on bigdata that provides services for foreign students who want to study in Korea, colleges that provide educational services, guides for interpreting and admission procedures, visa agency services and learning coordinator and counseling services.
  • 12.

    Effective Implementation for Fast Deep Learning Algorithm

    Sang Min Suh | 2019, 14(5) | pp.553~561 | number of Cited : 3
    Abstract PDF
    AI (Artificial Intelligence) based on deep learning has been successful in many application areas. Supervised learning such as image classification and object detection has been mainly used for vision and ADAS (Advanced Driver Assistance Systems) / AD (Autonomous Driving). And reinforce learning has been generally utilized for robotics and energy optimization. Therefore, in order to improve the performance, many research papers have focused on optimizing neural networks. However, in practice, FPS (frame per second) is a hidden and critical factor because FPS is also included in the performance measurement. This note show that pre-processing and post-processing are major components affecting FPS. And It is verified that FPS cannot be improved by optimizing the neural network itself because the pre-processing and post-processing are out of the neural networks. In this note, fast pre-processing methods on the basis of DSP (digital signal processing) is suggested. For DSP implementation, binary arithmetic is presented and quantization error due to the conversion from floating point calculation to fixed point calculation is discussed. In addition, major design frameworks for deep learning algorithm implementation are compared and their merit and demerit are also summarized. In the note, implementation is categorized into three, i.e., input data generation with pre-processing, model design of neural network, and performance evaluation. With the selected framework, detailed implementation is also presented.
  • 13.

    Sensory Attributes of Various Noni(Morinda citrifolia) Muffins Using Quantitative Descriptive Analysis

    Hyeyoung Kim | hyeyoung kim | 2019, 14(5) | pp.563~573 | number of Cited : 0
    Abstract PDF
    To evaluate the effect of Noni powder on muffins, muffins were made with Noni powder(0,10,20,30 % (w/w)). The moisture contents did not show any significant difference among groups. pH of the muffins with only 30% of Noni powder were significantly lower than that of the control group. No significant weight changes were observed at weight. However, Baking loss Rate of muffins with 10% Noni powder was significantly lower than that of the control group. The volume of samples was reduced by addition of Noni powder. And no significant difference was found among groups at uniformity and symmetry index. In color, control group showed the highest L-value and b-value among groups. A-value of the control group showed the lowest rather than that of the other groups. Hardness of groups with Noni powder was reduced significantly as the increase of the amount of Noni powder. However, any significant difference at adhesivenes, springness, cohesiveness. Brown color, odor, juiciness intensity was increased significantly as the addition of Noni powder. Muffins with 10% Noni powder did not show any significant difference with the control group at appearance, flavor, texture and overall acceptability. As a result, 10% of Noni powder will be ideal to make muffins.
  • 14.

    A Design and Implementation of Danger Prevention Alarm System Based on the IoT

    SangJo Youk | Dong-Hyuk Kim | Jae-Hong Kim | 2019, 14(5) | pp.575~584 | number of Cited : 0
    Abstract PDF
    We suggest that risks can be prevented by developing IoT-based risk prevention alarm system using location information terminal. The proposed system can be divided into smartphone (administrator), mobile server, and location information terminal (user group). Location information terminal(user group) continuously receives GPS information and sends each device's latitude, longitude, and emergency execution information to the mobile server. A smartphone(administrator) sends GPS signals received through a GPS satellite to a mobile server, and a mobile server sends information on the administrator's location through a GPS satellite again. Smartphone(administrator) also receives maps of location information terminal(user group) and location information of user group ID. If a user deviates from a certain distance based on the administrator, a text message will be sent and a sound(beep) will be emitted to prevent an accident in advance. We have developed an application, which is mainly useful when the person in charge leads a large number of people. When moving to a destination or settling down, an alarm sounds to inform the leader if a particular person is out of the way of the leader. Therefore the accident can be prevented in advance. This system can also be used to track how they traveled at a given time and to prevent various accidents that can occur in a moving situation.