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pISSN : 1975-7700 / eISSN : 2734-0570

2020 KCI Impact Factor : 0.42
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2019, Vol.14, No.6

  • 1.

    Breathing Characteristics Analysis of Snoring State Using Air Flow in the Nose

    Kwangmin Hyun | HwanSeog Kim | Baek-Ki Kim | 2019, 14(6) | pp.585~594 | number of Cited : 0
    Abstract PDF
    In this paper, a method for analyzing breathing characteristics in real time by measuring the change in air pressure intensity flowing through the nasal cavity when snoring occurs, and an algorithm for separating and detecting signal components with converting the measured continuous time signal into discrete time signal were proposed. A commercial digital miniature piezo-resistive sensor was inserted into the nasal cavity to measure changes in air pressure intensity during breathing. The snoring phenomenon was analyzed with snore-breathing vibration within the audible frequency band, using the magnitude of the change in respiratory air pressure and the frequency characteristic causing the auditory effects. Although the digital small piezo-resistive sensor used in this experiment works slowly, we used the undersampled data for the digital signal processing because the purpose of the signal measurement is to obtain slowly varying respiratory air pressure signal and to detect and existence of snoring itself, not to analyze the exact frequency components of a snoring signal. Through this process, the normal respiratory signal component and the abnormal snoring signal component were separated using a real-time digital filter with the characteristic of they have different frequencies each other. And the snoring signal was detected with the envelope detection method to detect the length of time for snoring duration. Further, it is necessary to study the medical meaning analysis of the separated abnormal signal components, and to apply it to various types of snoring phenomena to be applied in real life.
  • 2.

    A Universal Middleware-based Small Satellite Module for Dynamic Service Platform

    Lee, Hae-Jun | 2019, 14(6) | pp.595~604 | number of Cited : 0
    Abstract PDF
    Recently, In the wake of the satellite service industry research has been spreading to convergence science. As a representative field of cross-platform technology lead to user driven approach about space application services. Universal Middleware could be make pre-design review step of small satellite unit development. It could be develop to easy integration for user application services between internal interface module and 3rd party’s information services. In this study presents extensible way between each module that consist of dynamic and correlation application services for small satellite development model unit. This model could be adopt to the on-board computer interfaces such as a satellite control data field unit, define function and etc. This interface module transfer a data and service process for applying to each unit of intelligent requirement and development parameter. The condition of requirements are proposed with public protocol and private interface module with variable simulation way. Consequently, look into the extensible and dynamic module of three structural model for a small satellite system to the on-board computer. Firstly, the shared instance model of dynamic module support between service registry and inventory that consist of Satellite Application Platform. It suggested interoperability process of connect to tracking and event handling. Secondly, it should be make sure about the way of dynamic module that private message model. It could be make figure out the function of each relation. Thirdly, it take a real time application load model with application launcher via extended public protocol and network inventory.
  • 3.

    A Study on Trends and Perceptions in Smart Factory: News Network Analysis

    Joung-Huem Kwon | Ho Lee | 2019, 14(6) | pp.605~614 | number of Cited : 2
    Abstract PDF
    Since a global breakdown of the recession in 2009, smart factory has been spotlighted as a new means to counter the manufacturing industry's crisis caused by labor shortages, excessive hikes in manufacturing costs and slowing productivity. With the rapid development of technologies leading up to the 4th Industrial Revolution, there are various research about smart factory as a means of creating new values. On the other hand, there is a negative perception. In order to establish a true smart factory, digital transformation of the entire manufacturing value chain must be preceded. It requires a tremendous amount of time and technical investment. Hence, some people doubt the feasibility of smart factory. Therefore, the purpose of this study was to find out the characteristics of two-sided value recognition of smart factory by deriving major issues for domestic smart factory and to contribute to the revitalization of the industry for smart factory. To this end, the major issues of smart factory in Korea were derived by conducting text network analysis based on 17,376 news reports from January 1, 2014 to December 31, 2018. As a result, trends in government-led projects, technology trends, industrial trends, and universities and education businesses were generally identified. On the government side, it was found that government wants to simultaneously create jobs and economic growth through a smart factory. In terms of technology, smart factory was being activated based on the world's first commercialized 5G network technology. On the industrial side, smart factory projects was led by a large corporations, and the business area was expanding from automobiles to energy. In terms of education, it was found that Universities in the Chungcheong provinces were found to be concentrating on nurturing human resources, mainly by establishing new departments related to smart factory.
  • 4.

    Anaysis for Public Bike Utilization Status of Seoul City

    Park Jang Woo | Cho Yong Yun | 2019, 14(6) | pp.615~623 | number of Cited : 1
    Abstract PDF
    Bicycles have played a great role not only as eco-friendly transportation, but also as exercise equipments for leisure and health. Cities in many countries offer public bicycle sharing services to help solve the health and traffic jams of citizens and to solve environmental problems caused by automobiles. To serve the efficient bike sharing, the knowledge of the status of bike use will be necessary. We have analyzed the data set of public bicycle service in Seoul to determine the temporal and spatial characteristics of bicycle use status in Seoul. The travel time and the latitude and longitude of the bike rental place and return places were transformed into 50 clusters using K-means clustering method. Spartial and temporal characteristics have been obtained and visualized. We can know the bicycle retal and return status according to the location of the City of Seoul. In addition, these clusters were classified and visualized for year, such as date, day of the week, time, etc. From the analysis, we could show the bike use patterns of weekday and weekend. During the weekday, the bikes are being guessed to be used for commute devices and for working assistance. On weekends, bicycles are slowly increasing from morning to high, peaking around 6pm. It is confirmed that during the week, there are many short-distance uses, and on weekends various travel distance patterns were seen.
  • 5.

    A Study on Comparison of the Machine Learning Models for the Trip Distance Prediction of the Seoul Public Bike Sharing Service

    Park Jang Woo | Chang-Sun Shin | 2019, 14(6) | pp.625~634 | number of Cited : 0
    Abstract PDF
    Cities in many countries offer public bicycle sharing services to help solve the health and traffic jams of citizens and to solve environmental problems caused by automobiles. Using the machine learning models, the public bike service in Seoul have been analyzed. To service the bike sharing efficiently, the prediction of trip distance or trip duration will be needed. The prediction of trip distances and durations has important roles to help the proper operations and improvement of the bike rental services. The trip distances are deeply related to the trip durations, and could be calculated accurately when including the positions of pickup and return places, environment information such as temperature, humidity, fine dust density, et., al. To build models, linear regression, Random Forest, XGBoost and deep learning techniques have been used. Random Forest and XGboost provides important features among features. Especially, XGBoost being interested in many data manipulating and anlysing areas shows improved accuracy and can utilized the GPU to boost speed. To apply the deep learning in analysis of structured data(tabula data), embedding of categorical features will be done and the remaining continuous features and embedded features put into the fully connected neural nets. The deep learning neural net model shows the best accuracy and then XGBoost model, Random Forest models followed.
  • 6.

    A Study on Development of Performing Arts Demand Index by Region

    Song, Woo-Young | 2019, 14(6) | pp.635~643 | number of Cited : 0
    Abstract PDF
    In Korea, with the rapid growth, the size of the performing arts market has increased greatly. However, there are also problems such as growth biased to specific sectors and regional biases centered on the metropolitan area. Therefore, in the field of performing arts, there is a need for the appropriate supply of performance arts and facilities suitable for the demand level of each region. In this study, the regional performing arts demand index was developed in order to derive improvement measures for these problems. Also, this paper presented a method to utilize the developed performance art demand index. In order to calculate the demand index, the ratio of 20s and 30s in economically active population and income per capita were selected as input factors for performing arts demand. As the performance factor of performing arts demand, the average number of performance days and operation rate were selected. The selected factors were converted into standardized scores and applied to the index. Also, the structure of the integrated database system for periodic calculation of regional indexes is presented. As a result of index calculation based on 2017, the demand index of metropolitan area such as Seoul and local metropolitan city is higher than that of other regions. The comparison of the demand index by region and the number of seats per thousand people showed that the number of seats was relatively low compared to the demand in Ulsan and Incheon, and the number of seats in Gangwon-do and Jeollanam-do was higher than the demand. As a result of analyzing the three-year demand index by region, the demand index fell the most in Daegu compared to three years ago, and the index rose the most in Gwangju and Jeju.
  • 7.

    Effects Analysis of Lesson Plan Using Instructional Ontology

    DuGyu Kim | Jaemu Lee | 2019, 14(6) | pp.645~653 | number of Cited : 0
    Abstract PDF
    This study is to design the lesson plan using the instructional ontologies by the novice designers and evaluate the effectiveness of the designed lesson plan through the blind test. The blind test compares the two methods. One method is to design their own lesson plan using traditional methods by novice designers. Another method is to design lesson plans by means of instructional ontologies for novice designers. The novice designers were randomly divided into two groups, and different development methods were applied to the same subject to develop a lesson plan. These lesson plans were compared through the blind test by eleven experts. As a sequence, experts found out the lesson plans made by instructional ontologies were better than those developed by the traditional method with a reliability of 0.7. The reasons are as follows. First, the characteristics of the instructional model are clearly expressed, and the activities of each step are described in detail. Second, instructional strategies and overall organization are systematic and well planned. The instructional strategies provided in the instructional ontologies assist in the systematic design and the achievement of learning goals. Third, it mentioned each stage of the instructional model is described in detail. In conclusion, the proposed lesson plans using instructional ontologies clearly expressed the instructional model. Their overall composition was systematic, and the instructional strategies were expressed in each step. However, it is necessary to study how novice designers can effectively utilize instructional ontologies.
  • 8.

    Design of IOT-based Anti-Theft System with Remote Control

    Moon-Seog Han | Won-Seub Lee | 2019, 14(6) | pp.655~663 | number of Cited : 0
    Abstract PDF
    We are now seeing many cases of theft of public goods used for emergencies. In this case, an accident may occur that does not cope with a sudden crisis situation smoothly. There is a need for a system that can prevent and track these thefts in advance. Some of the public goods are stolen, for example, AED(Automated External Defibrillator) and fire extinguishers. Even if there is a closed circuit television(CCTV) nearby, we can see that blind spots exist and goods are accidentally stolen. To prevent this situations, we require systems that can be prevented and tracked in advance. Apart from the various expensive GPS tracking devices that are available in the market, we introduce IoT-based anti-theft system with remote control that works only using GPS and open source technologies which makes it cheapest system for public goods management. We used Arduino as open hardware equipped with a GPS(Global Positioning System) sensor in that can identify the location of public goods in the event of theft. By confirming the impression of the person who took the goods with the camera sensor on the Arduino with the alarm sound, we designed our system to prevent theft of public goods. Finally, we design a system that developed and tested successful working android application for Internet of Things. In this paper we proposes the IoT-based anti-theft system to prevent theft situation.
  • 9.

    A Study on Financial Time Series Data Volatility Prediction Method Using AI's LSTM Method

    Han Jin Song | Heung Sik Choi | Kim Sun Woong and 1other persons | 2019, 14(6) | pp.665~673 | number of Cited : 0
    Abstract PDF
    The purpose of this study is to predict the future volatility of financial instruments more effectively by utilizing Long Short Term Memory (LSTM) which is one of the artificial intelligence (AI) techniques. This study focused on the method of predicting the future forecasts based on the historical data through the LSTM technique. The future price of a financial instrument is inversely proportional to the instrument’s size of future volatility. Therefore, if future volatility can be predicted for the targeted financial instrument, the fluctuation in the instrument’s price in the future can be projected more effectively. This paper predicts the future price volatility by making the historical data of a financial instrument to learn by using AI technique. As a result, the volatility movement predicted by AI was significantly similar to the actual volatility value during the same period. Through this, the results of this study are expected to be used to forecast the price of financial products more effectively. In addition, it is expected that the results of this study, together with other existing methods for volatility prediction, will further contribute to the accuracy of projecting the future volatility, and ultimately contribute to the improvement in investment returns of financial investments products including funds.
  • 10.

    Design of Rectangular Patch Microstrip Antenna for Mobile Devices

    Choi, Jae Yeon | 2019, 14(6) | pp.675~682 | number of Cited : 0
    Abstract PDF
    We design a small microstrip patch antenna with rectangular patches for use in mobile communication devices for mobiles. As can be seen from the results of the designed antenna, the small microstrip patch antenna was designed to have a center frequency of 1.91 GHz, which was successful. The ground plane dimensions of the patch antenna are designed to be 31mm x 40mm, and the patch dimensions are 22mm x 31mm. The designed antenna is sized enough to fit into a typical mobile communication device. Reduced posterior lobe radiation has been obtained, which is an additional advantage of the antenna when applied to mobile terminals because it minimizes the amount of electromagnetic energy radiated towards the user's handset. A gain of 1.87 dBi and a directivity of 5.56 dBi were obtained. The bandwidth obtained for this antenna is 23.28 MHz, and time division systems and global systems of mobile communications use 30 KHz channels, which is sufficient for personal mobile terminals. When mobile phones are connected through satellite networks to provide services to users, different networks must be able to operate the mobile terminal's antennas at separate frequencies. Work must be done to design a dichroic or trichromatic microstrip patch antenna that can operate at four or three frequencies and be used for many applications.
  • 11.

    Asymmetric Key Cryptographic Authentication Model for IP Spoofing in Cloud Environments

    Young Jin Baek | suk won, Hong | Lee, Chang-Heui and 1other persons | 2019, 14(6) | pp.683~691 | number of Cited : 0
    Abstract PDF
    Today's cloud-based network services demand strong security. However, in an environment where real-time provision of service resources is essential, it is caused by an enhanced security policy, which causes a decrease in quality of service availability. In addition, IP spoofing attacks, which can severely damage network availability and integrity, can be more frequent in cloud service environments. Therefore, systems that perform cloud services need to establish new security policies and systems that can guarantee availability and integrity. Conventional detection and response methods for IP spoofing include analyzing traceback information and performing authentication through OTP when different paths occur. However, this method can degrade service availability because OTP is generated every time a different path is detected. In addition, in order to improve this, a pattern-based encryption scheme may leak decryption information by a sniffing attack. In order to improve this problem, this paper replaces the authentication process with the normal decryption based on traceback information instead of the encryption process after analyzing the existing access information. Based on this, reauthentication over OTP is performed only when the client's IP is different and when normal decryption cannot be performed. In addition, it solved the problem of excessive OTP generation and presented an authentication model that enables continuous service in real time.
  • 12.

    A Study on the Optimization of Efficient Node-to-Node Disturbance Detection System

    Byoung-Chan Jeon | Hong,In-Sik | 2019, 14(6) | pp.693~702 | number of Cited : 1
    Abstract PDF
    A major loss factor for water resources is leaks or pipe damage that prevent the transport of water resources. Leakage or damage of these water pipes is caused by damage caused by aging of the life of the pipes, corrosion on the surface of the pipes, construction of pipes or installation conditions, water supply conditions, and accidents. There are currently a variety of water leak detection techniques applied to the top and bottom pipe networks. Among these systems, existing systems are developed using flow meters, hydraulic pressure systems, ultrasonic waves, optical cables, and monitoring systems using TDR. However, there are many cases where systems are not installed efficiently and cannot be monitored. In addition, existing PC-based systems with high prices need to develop embedded board-based low-cost systems because they are not cost-effective when applying the system to short-range pipelines. However, there is a limitation in function of SW that is currently used on site as it is also developed based on PC. In this paper, the existing monitoring system has the disadvantage of being economically expensive when replacing old pipe or short track less than 1,000m, and that it is too much to cover with existing system even when installing short section or different kinds of landscape. To address these shortcomings, the distance between nodes of the break detection system was optimized for optimal monitoring and development of a water leak detection system with high constructivity and economy by using leak detection sheets (hereinafter referred to as the leak detection sheet).
  • 13.

    A Study on the Strategy of Korean Companies to Enter the Overseas App Market through the Cases in the Philippines

    Kim, Kwang-hyun | Dong-Gil Oh | 2019, 14(6) | pp.703~710 | number of Cited : 1
    Abstract PDF
    In this study, domestic application companies are saturated, and foreign application companies such as Utube, Twitter, Hotelscombine, and Twitch TV are penetrating into the domestic market. On the other hand, domestic companies are not focusing on quality improvement and new business, but focusing on marketing and advertising. One way to overcome this is to pioneer new overseas markets. In developed countries such as the US, Japan, and Europe, there are many market demands, but there are many competitors. Smartphone performance is rising sharply in Southeast Asia in 2019, but the number of applications in use is less than half of those in developed countries on average. Philippine application market is expected to be higher than competitors in other Southeast Asian markets but because it speaks English, it is not difficult to enter the Philippine application market. The study also revealed why domestic application companies should enter overseas markets to find new customers. This study analyzed the cases of domestic application companies failing and successfully entering overseas markets. In addition, by analyzing the infrastructure and utilization of the Philippines in terms of the app industry, we propose strategies for domestic companies to enter the Philippines application market more easily and safely.
  • 14.

    Formal Specification of Cryptographic Security Protocols

    Lee, Gyesik | 2019, 14(6) | pp.711~718 | number of Cited : 1
    Abstract PDF
    We introduce a way of formal specification of cryptographic security protocols. We demonstrate how to use formal methods in verifying cryptographic security protocols. Each step of the verification is explained with a concrete example, the Needham-Schroeder public-key protocol. The style of describing the syntax is similar to that of the tool Scyther. It is simple and intuitive to use for the specification of security protocols. Our description corresponds also to the basic concepts of the tool ProVerif. Specifications of cryptographic security protocols are represented at the most abstract level: Messages are terms constructed from symbols and the attacker is modeled as a formal process. A formal language L = (V, C, R, F) for public-key protocols consists of a set V of variables for received messages, a set C of local constant symbols, a set R of role name symbols, and a set F of function symbols. Then a protocol describes the behavior of each of the roles such as initiator, responder, key server, etc. In the specification, the behavior of each role is formalized as a transition system describing how to create messages, how to react to the received messages, and how to manipulate messages. Among many security properties, we illustrate how to formally handle secrecy and authentication.
  • 15.

    A Big Data-based Analysis of Policy Trends ofChild-Friendly City in Local Governments

    Eeh-Eun Song | Jiyeon Kim | 2019, 14(6) | pp.719~728 | number of Cited : 0
    Abstract PDF
    Child-friendly cities refer to an infrastructure that enables children with diverse characteristics to enjoy happiness. Child-friendly cities should be able to strengthen their effectiveness rather than remain in a single brand, value and ideology. Now it is necessary to pay attention to the specific entities and contents for the guarantee of children's rights. However, numerous studies have only been focused on the values and justification sought by child-friendly cities. In this paper, we look for future directions by diagnosing the status of child-friendly cities. We focus on Seoul metropolitan, which is actively promoting the creation of child-friendly cities. We collect a number of news articles from Naver, the biggest web portal in South Korea. We then analyze the child-friendly trends from the massive news articles by employing Big data technology. Analysis of association rules as well as keyword frequency has been addressed to identify the specific entities, main targets and major areas of promotion of child-friendly cities. We find out that the characteristics of child-friendly cities are similar between Seoul and the other local governments. We suggest that future child-friendly cities should be able to take the initiative in the participation of various entities. Furthermore, child-friendly cities should reflect the diversity of children and promote universal diffusion as well as characterization simultaneously. In the future, many efforts to create a sustainable child-friendly cities are required by promoting public-private governance and developing diverse contents.