• Journal of Convergence Society for SMB
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• v.6 no.3
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• pp.21-27
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• 2016

In this paper, we introduce the PB/MC-CDMA (Partial Block/Multi-Carrier-Code Division Multiple Access) system to mitigate inter-cell interference (ICI) and enhance user capacity in the small cell environment. In 5G mobile communications, the number of devices connected to the network is expected to increase exponentially with the expansion of the IoT (Internet of Things) services. In addition, each device is expected to be required by the various data rates by their content types. In LTE/LTE-A, there are some limitations that large scale connectivity and supporting various data rates. Therefore, we introduce a PB/MC-CDMA physical layer system which is suitable for the small cell environment, and evaluate the performance in the multi cell environment which is affected by ICI. Through computer simulation results, we demonstrate the effectiveness of PB/MC-CDMA for the small cell environment.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.6
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• pp.565-570
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• 2015

In this paper, we implemented the smart door lock system that control remotely devices using the concept of internet of things. Internet of things is intelligent system that can help devices to communicate with people and devices. And recently internet of things is getting attention because of advance of hardware technology and big data. The smart doorlock system based on internet of things used raspberry pi, sensor and doorlock. Using the smart phone, doorlock can be controlled from the raspberry pi server. And the user can identify some people that is in front of doorlock. also user can check around of doorlock in realtime using the raspberry pi camera.

• KIISE Transactions on Computing Practices
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• v.23 no.11
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• pp.641-649
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• 2017

As Internet of Things devices become pervasive, services improve to better assess the context and to alert other users to deal with emergencies. Such services use Internet of Things devices to detect the context around the user and promptly notify public institutions, hospitals or other parental users in emergencies. Most of these systems analyze an event when the value of the device is unchanged for a period of time or if it detects an abnormal value. However, just monitoring sensor values makes it difficult to accurately understand the context surrounding a user. Also if the device is inactive, it can not identify the context or provide services again. However, understanding the user requirements, services provided through other devices, information sent to other users lets, appropriate actions be taken. This paper, proposes a device search method and system based on a context-aware model that includes user demands. The proposed system analyzes the user's context and demands by using data collected from the internet of things devices. If user devices are inactive, they can recognize other devices by searching for other devices and providing services to users again. Through the proposed method, the user-centric services are provided. This method also analyzes and responds to requirements in various emergencies.

• Journal of Internet of Things and Convergence
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• v.6 no.1
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• pp.31-38
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• 2020

This study was intended to verify the parameter effects of empowerment in the effect of social support of the employees of youth training facilities on the quality of service. The purpose of this study was to provide basic data for improving the service quality of youth training facility workers. As a result of this study, first, social support and empowerment had a positive effect on service quality. Second, the partial mediating effect of empowerment can be confirmed. Based on the results of this study, the following suggestions were made. First, for the social support of the employees, the middle managers and facility managers of youth training facilities should use the Internet environment such as the Internet and smart phones. Second, in order to improve empowerment, support for information related to work, material support related to compensation, and evaluation support related to business processing should be provided. Third, to improve the empowerment of workers, it is necessary to augmented reality(AR), virtual reality(VR), and flip learning program using the Internet of Things environment.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.1
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• pp.47-55
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• 2016

As one of recent issues in the information and communication industry, internet of things has attracted attention to provide intelligent infrastructure services which connect and share data and information between real and virtual world. According to the development of these internet of things technologies, types of machines, telecommunication devices, and terminals are increasing tremendously. In this situation, connectivity and interoperability between internet of things components are important issues to build a hyper connected society. To visualize this society, it is important to set up and develop information and communication technology (ICT) standards among stakeholders. However, under limited budget and human resources, it is essential to rank standardization work items for setting standards with respect to efficiency. The purpose of this study is to provide a method for setting standardization strategies within group decision making. As a multi-criteria group decision making tool, analytic hierarchy process (AHP) is adopted and applied to determine the priorities of setting work items. The proposed method first defines decision making problem with objective, criteria, and alternatives which produces a hierarchy consisting of upper and lower criteria. Then, pairwise comparisons of academy and public sector experts are performed with respect to their relative meaning and importance. Individual surveys of expert groups are collected and summarized to determine relative criteria importance measures. Furthermore, to deliver reliable importance criteria measures, differences between academy and public sector expert groups are compared and tested using Mann-Whitney non-parametric test. The results are illustrated for useful guidelines to practical group decision making in standardization strategy establishments.

• Journal of Internet of Things and Convergence
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• v.9 no.6
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• pp.17-22
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• 2023

Brain-Machine Interfaces(BMI) are interfaces that control machines by decoding brainwaves, which are electrical signals generated from neural activities. Although BMIs can be applied in various fields, their widespread usage is hindered by the low portability of the hardware required for brainwave measurement and decoding. To address this issue, previous research proposed a brain-machine interface system based on the Internet of Things (IoT) using cloud computing. In this study, we developed and tested an application that uses brainwaves to control the Pong game, demonstrating the real-time usability of the system. The results showed that users of the proposed BMI achieved scores comparable to optimal control artificial intelligence in real-time Pong game matches. Thus, this research suggests that IoT-based brain-machine interfaces can be utilized in a variety of real-time applications in everyday life.

• Journal of Internet of Things and Convergence
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• v.8 no.1
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• pp.17-22
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• 2022

This paper is a study on the self-powered wireless bus information and disaster information system based on Internet of Things (IoT). The existing bus information system supplies power and communication by cable, which causes a problem of increased installation cost and limited installation site due to cable burial. To solve this problem, a self-powered wireless bus information and disaster information system was proposed. The proposed system provides bus arrival information. Furthermore, in the event of a disaster such as a natural disaster, it can also reduce confusion and damage by notifying the disaster information through the system's speaker. In this study, a self-powered system using a solar module was proposed. As data are transmitted and received through wireless WiFi or LTE, the installation cost can be reduced and the problem of installation location restrictions can be solved.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.9
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• pp.1159-1164
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• 2018

Recently, Internet use is increasing in various fields. Especially in the sudden disaster area, the role of Internet of things that can continuously monitor is getting bigger. In this study, the characteristics of the confined space and the environmental hazards are examined, and the Internet of the object which is being commercialized will be reviewed. Accidents in confined spaces are very high compared to other places, and it is very difficult to predict accidents. Recently, various attempts have been made to prevent accidents in confined spaces using the Internet of things. Especially, it detects the various gases that can occur in the closed space using sensors and sends them to the workers in real time, so that the risk can be detected in advance to minimize the risk. In this paper, we propose an effective disaster prevention plan using the Internet of things through the case study of the Internet for the prevention of accidents in a confined space.

• Smart Media Journal
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• v.4 no.3
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• pp.62-67
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• 2015

The trend keywords in ICT sector will be Big Data, Internet of Things, and Cloud Computing. The rear end to support those techniques requires a large-capacity storage technology of low-cost. Therefore, we proposed the prototype of low-cost and mass distributed storage system based on PC using open-source Ceph FS for SMB.

• Journal of KIISE
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• v.44 no.12
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• pp.1296-1306
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• 2017

Recently, as the number of Internet of Things users has increased, IETF (Internet Engineering Task Force) has released the CoAP (Constrained Application Protocol). So Internet of Things have been researched actively. However, existing studies are difficult to adapt to streaming service due to low transmission rate that result from buffer underflow. In other words, one block is transmitted one block to client's one request according to the internet environment of limited resources. The proposed scheme adaptively adjusts the rate of CON(Confirmable) message among all messages for predicting the exact network condition. Based on this, the number of blocks is determined by using buffer occupancy rate and content download rate. Therefore it improves the quality of user experience by mitigating playback interruption. Experimental results show that the proposed scheme solves the buffer underflow problem in Internet of Things streaming environment by controlling transmission rate according to the network condition.