Korean | English

pISSN : 2466-0078

2020 KCI Impact Factor : 0.0
Home > Explore Content > All Issues > Article List

2020, Vol.6, No.4

  • 1.

    The Smart Contract based Conference Key Distribution Scheme

    SungHyun Yun | 2020, 6(4) | pp.1~6 | number of Cited : 0
    Recently, epidemic of covid-19 causes rapid increase in demand for untact video conferences. In existing server-client based video conference systems such as Zoom, Google Meet, etc., the server generates the conference key and controls the access rights of meeting members and their contents with it. In this case, the server can fabricate or repudiate the meeting. So, the privacy of the meeting members is not guaranteed. It’s necessary to make the conference key distribution scheme where all participants can verify the trustfulness without help of the server. The smart contract is the program stored to the blockchain. Its contents cannot be altered due to the property of the blockchain, and everybody can verify the execution results of it. In this study, we propose the smart contract based conference key distribution scheme. The proposed scheme is consisted of smart contract deployment, conference key generation and verification stages. The smart contract replaces the role of existing trustful server and the meeting members can generate the conference key according to the protocols implemented on it. The proposed scheme can be applied to the video conference systems and only the meeting members can access the conference key.
  • 2.

    IoT Utilization for Predicting the Risk of Circulatory System Diseases and Medical Expenses Due to Short-term Carbon Monoxide Exposure

    Lee, Sangho | Kwangmoon Cho | 2020, 6(4) | pp.7~14 | number of Cited : 0
    This study analyzed the effect of the number of deaths of circulatory system diseases according to 12-day short-term exposure of carbon monoxide from January 2010 to December 2018, and predicted the future treatment cost of circulatory system diseases according to increased carbon monoxide concentration. Data were extracted from Air Korea of Korea Environment Corporation and Korea Statistical Office, and analyzed using Poisson regression analysis and ARIMA intervention model. For statistical processing, SPSS Ver. 21.0 program was used. The results of the study are as follows. First, as a result of analyzing the relationship between the impact of short-term carbon monoxide exposure on death of circulatory system diseases from the day to the previous 11 days, it was found that the previous 11 days had the highest impact. Second, with the increase in carbon monoxide concentration, the future circulatory system disease treatment cost was estimated at 10,123 billion won in 2019, higher than the observed value of 9,443 billion won at the end of December 2018. In addition, when summarized by month, it can be seen that the cost of treatment for circulatory diseases increases from January to December, reflecting seasonal fluctuations. Through such research, the future for a healthy life for all citizens can be realized by distributing various devices and equipment utilizing IoT to preemptively respond to the increase in air pollutants such as carbon monoxide.
  • 3.

    Optimal CW Synchronization Scheme in IEEE 802.11 WLANs

    Jin-Lee Lee | Su-Bin Lee | Yeun-Woong Kyung | 2020, 6(4) | pp.15~19 | number of Cited : 0
    In this paper, we propose a optimal CW(Conention Window) synchronization scheme in IEEE 802.11 WLANs. IEEE 802.11 WLANs support DCF(Distributed Coordination Function) mode for the MAC(Medium Access Control) operation. In DCF, the CW increases exponentially according to the collisions and becomes minimum CW according to the success of data transmissions. However, since the base minimum CW value is hardware or standard specific, the number of active stations and network status are not considered to determine the CW value. Even though the researches on optimal CW have beend conducted, they do not consider the optimal CW synchronization among mobile stations which occur network performance degradation. Therefore, this paper calculates the optimal CW value and shares it with mobile stations in the network.
  • 4.

    Metallic FDM Process to Fabricate a Metallic Structure for a Small IoT Device

    IngooKang | Sun-Ho Lee | Dong-Jin Lee and 2other persons | 2020, 6(4) | pp.21~26 | number of Cited : 0
    An autonomous driving system is based on the deep learning system built by big data which are obtained by various IoT sensors. The miniaturization and high performance of the IoT sensors are needed for diverse devices including the autonomous driving system. Specially, the miniaturization of the sensors leads to compel the miniaturization of the fixer structures. In the viewpoint of the miniaturization, metallic structure is a best solution to attach the small IoT sensors to the main body. However, it is hard to manufacture the small metallic structure with a conventional machining process or manufacturing cost greatly increases. As one of solutions for the problems, in this work, metallic FDM (Fused depositon modeling) based on metallic filament was proposed and the FDM process was investigated to fabricate the small metallic structure. Final part was obtained by the post-process that consists of debinding and sintering. In this work, the relationship between infill rate and the density of the part after the post-process was investigated. The investigation of the relationship is based on the fact that the infill rate and the density obtained from the post-processing is not same. It can be said that this work is a fundamental research to obtain the higher density of the printed part.
  • 5.

    Design of Remote Early Dementia Diagnosis Systems

    Choi, Jong Myung | Jeon Gyeong Suk | Sun Kyung Kim and 3other persons | 2020, 6(4) | pp.27~32 | number of Cited : 0
    Along with the aging of the population, the number of dementia patients is increasing, and the social and economic burden is also increasing. Currently, the effective way to manage dementia patients is to identify patients with dementia early. However, in rural and island areas where medical staff are scarce, there is a problem that it is difficult to visit a hospital and get an early examination. Therefore, we propose a remote early detection system for dementia to solve the problems. The remote dementia early diagnosis system is a system that allows a patient to receive examination and treatment from a remote dementia expert using remote medical technology based on real-time image communication. The remote early diagnosis system for dementia consists of a local client system used by medical staff at health centers in the island, an image server that transmits, stores and manages images, and an expert client used by remote dementia experts. The local client subsystem satisfies the current medical law's remote collaboration by allowing the patient to use it with the health center's medical staff. In addition, expert clients are used by dementia experts, and can store/manage patient information, analyze patient history information, and predict the degree of dementia progression in the future.
  • 6.

    Construction of Dyeing Condition System for Lithospermum erythrorhizon by Applying Natural Dye and Mordants

    JUNG SUK YUL | 2020, 6(4) | pp.33~38 | number of Cited : 0
    It was reported that a mobile application was designed to easily provide natural dyeing information such as natural dye related resources, colors and dyed fabrics in 2007. Since studies on the linkage, application, etc. between natural dye dyeing and IoT are still lacking, diversity of information on the change of dyeing pattern by natural dye dyeing is required. In this study, it was to construct dyeing information by natural dyes, e.g., Lithospermum erythrorhizon, on silk, which has been traditionally used as many fibers in Korea. The extraction of the dye from L. erythrorhizon was carried out under pH4. The dried root of L. erythrorhizon showed dark brownish purple. Silk fabric by a without a mordant typically showed a purple dyed pattern. In the staining by sodium tartrate plus citric acid, silk fabric was stained clear brown. Interestingly, the mordant of iron (II) sulfate, the silk fabric was dyed in a light gray color rather than black. When the mordant of aluminum potassium sulfate was treated with L. erythrorhizon-extracted dye, the results were almost the same as when the mordant was not treated. When the degree of dyeing was evaluated numerically, the treatment of the mordant of potassium dichromate was about 50% darker, and the dyeing by iron (II) sulfate was about 75% darker. These results will be helpful in the study of applying various dye colors using L. erythrorhizon, and it will provide information on dyeing controller and database system construction by dyeing parameters such as dyeing degree, pH concentration, and chromaticity change.
  • 7.

    Analysis on the Transition and Determinants of Long-Term Care Service for the Elderly in the Internet of Things era

    Choi, Jang Won | 2020, 6(4) | pp.39~48 | number of Cited : 0
    This study intends to the estimate the determinants and state dependence of long-term care services in Korea. For this purpose, we analyzed the transition patterns among three states of long-term care service utilization over time by using the Korea Welfare Panel Study data with the random effect multinomial logit model. It is found that the result showed a strong state dependence in long-term care service utilization. Especially, long-term care insurance for the elderly showed a strong state dependence among others. Among the individual demographic characteristics, the higher the age, the higher the probability of using long-term care insurance for the elderly, while the lower the probability when married. The characteristics of the residential region showed that the residents of the urban-rural integrated region had a significantly higher probability of using long-term care insurance than the reference region. The results of this study suggest that the long-term care service users have a strong state dependence, which means that it is important to take into account the increase in the utilization period of existing users in future demand forecasting.
  • 8.

    A study on the approximation function for pairs of primes with difference 10 between consecutive primes

    Lee, Heon Soo | 2020, 6(4) | pp.49~57 | number of Cited : 0
    본 논문은 연속하는 두 소수의 차가 10인 소수의 쌍의 수에 대한 계산 함수   의 근사함수    를로그적분을 이용하여 유도하였다.    가   의 근사함수로 적절한지 알아보기 위하여 컴퓨터와Mathematica 프로그램을 이용하여   와    의 값을  ≤ 까지 구한 후 두 값의 오차율을 계산하였다. 오차율을 계산한 결과 대부분의 구간에서 오차율이 0.005% 이하로 나타났다. 또한, 두 소수의 차가 10인 소수들의 역수들의 합  ∞이 유한임을 보였다.  ∞의 수렴값을 구하기 위하여   을 구한 후, 이를 이용하여 ∞의 대략적인 수렴값을 계산하였다. 그 결과  ∞  ±×  로 수렴함을 알 수 있었다.
  • 9.

    Research on Efficient Smart Factory Promotion System in IoT Environment

    DongWoo Lee | Kwangmoon Cho | Lee Seong Hoon | 2020, 6(4) | pp.59~64 | number of Cited : 0
    Recently, many difficulties have been faced in all parts of the world due to the impact of COVID-19. Personally, household income is decreasing sharply as many jobs disappear, and economically, many SMEs are increasingly going bankrupt. It is known that this phenomenon is highly likely to continue for the time being. In such a situation, the smart factory support project provides opportunities for difficult SMEs to improve productivity and change the corporate structure. In this study, the current status of smart factory promotion was examined, and problems occurring in the process of promoting smart factory support projects were identified. The improvement plans were derived so that more efficient projects could be promoted in the future.
  • 10.

    Design and Implementation of Machine Learning-based Blockchain DApp System

    Lee, Hyung Woo | HanSeong Lee | 2020, 6(4) | pp.65~72 | number of Cited : 0
    In this paper, we developed a web-based DApp system based on a private blockchain by applying machine learning techniques to automatically identify Android malicious apps that are continuously increasing rapidly. The optimal machine learning model that provides 96.2587% accuracy for Android malicious app identification was selected to the authorized experimental data, and automatic identification results for Android malicious apps were recorded/managed in the Hyperledger Fabric blockchain system. In addition, a web-based DApp system was developed so that users who have been granted the proper authority can use the blockchain system. Therefore, it is possible to further improve the security in the Android mobile app usage environment through the development of the machine learning-based Android malicious app identification block chain DApp system presented. In the future, it is expected to be able to develop enhanced security services that combine machine learning and blockchain for general-purpose data.
  • 11.

    Mitigate the Relational Aggressive Attitude of the Elderly through the Convergence Program of Tea Culture Treatment Program : For the elderly women who use the Senior Citizen's Day Care Center

    Insook kim | 2020, 6(4) | pp.73~79 | number of Cited : 0
    In order to verify the effectiveness of the tea culture treatment program to mitigate the relative aggressiveness, the research will target 10 women aged 70 or older who use the P City-based Senior Citizens' Day Care Center to apply the tea culture treatment program to alleviate the relative aggressiveness of the elderly and examine its effects. As a result of the analysis, the score of reactive relational aggressiveness and leading relational aggression is 0.21 lower than the pre-exam average, indicating that the leading relational aggression of the elderly who participated in the tea culture therapy program is reduced than before the program. Based on these analysis results, practical suggestions were made for alleviating aggression among senior citizens using the Center for the Elderly.
  • 12.

    A Design on The Zone Master Platform based on IIoT communication for Smart Factory Digital Twin

    Seon-Hui Bak | Jong-Hwan Bae | 2020, 6(4) | pp.81~87 | number of Cited : 0
    This paper creates a standard node for acquiring sensor data from various industrial sensors (IoT/non-IoT) for the establishment of Smart Factory Digital Twin, and provides inter-compatible data by linking zones by group/process to secure data stability and to ensure the digital twin (Digital Twin) of Smart Factory. The process of the Zone Master platform contains interface specifications to define sensor objects and how sensor interactions between independent systems are performed and carries out individual policies for unique data exchange rules. The interface for execution control of the Zone Master Platform processor provides system management, declaration management for public-subscribe, object management for registering and communicating status information of sensor objects, ownership management for property ownership sharing, time management for data synchronization, and data distribution management for Route information on data exchange.
  • 13.

    Delayed offloading scheme for IoT tasks considering opportunistic fog computing environment

    Yeun-Woong Kyung | 2020, 6(4) | pp.89~92 | number of Cited : 0
    According to the various IoT(Internet of Things) services, there have been lots of task offloading researches for IoT devices. Since there are service response delay and core network load issues in conventional cloud computing based offloadings, fog computing based offloading has been focused whose location is close to the IoT devices. However, even in the fog computing architecture, the load can be concentrated on the for computing node when the number of requests increase. To solve this problem, the opportunistic fog computing concept which offloads task to available computing resources such as cars and drones is introduced. In previous fog and opportunistic fog node researches, the offloading is performed immediately whenever the service request occurs. This means that the service requests can be offloaded to the opportunistic fog nodes only while they are available. However, if the service response delay requirement is satisfied, there is no need to offload the request immediately. In addition, the load can be distributed by making the best use of the opportunistic fog nodes. Therefore, this paper proposes a delayed offloading scheme to satisfy the response delay requirements and offload the request to the opportunistic fog nodes as efficiently as possible.