• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.410-424
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• 2021

Background: Subway stations have the characteristics of being located underground and are a representative public-use facility used by an unspecified number of people. As concerns about indoor air quality (IAQ) increase, various management measures are being implemented. However, there are few systematic studies and cases of long-term continuous measurement of underground station air quality. Objectives: The purpose of this study is to analyze changes and factors influencing IAQ in subway stations through real-time continuous long-term measurement using IoT-based IAQ sensing equipment, and to evaluate the IAQ improvement effect of a bio-filter system. Methods: The IAQ of a subway station in Seoul was measured using IoT-based sensing equipment. A bio-filter system was installed after collecting the background concentrations for about five months. Based on the data collected over about 21 months, changes in indoor air quality and influencing factors were analyzed and the reduction effect of the bio-filter system was evaluated. Results: As a result of the analysis, PM₁₀, PM_2.5, and CO₂ increased during rush hour according to the change in the number of passengers, and PM₁₀ and PM_2.5 concentrations were high when a PM warning/watch was issued. There was an effect of improving IAQ with the installation of the bio-filter system. The reduction rate of a new-bio-filter system with improved efficiency was higher than that of the existing bio-filter system. Factors affecting PM_2.5 in the subway station were the outdoor PM_2.5, platform PM_2.5, and the number of passengers. Conclusions: The IAQ in a subway station is affected by passengers, ventilation through the air supply and exhaust, and the spread of particulate matter generated by train operation. Based on these results, it is expected that IAQ can be efficiently improved if a bio-filter system with improved efficiency is developed in consideration of the factors affecting IAQ and proper placement.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.162-163
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• 2017

IoT 기술의 발달로 지능적 관계를 형성하는 사물 공간 연결망으로 다양한 산업분야에 활용되고 있으며, IoT 시스템을 구축하기 위한 무선 통신 기술들도 연구되고 있다. Zigbee는 대표적인 무선 통신 표준 기술로 IoT의 Smart Home, Smart Led와 같은 분야에서 활용되고 있다. Zigbee 장비의 commissioning 기법은 사용자를 고려한 IoT 환경에서는 해결해야 할 과제이며, RSSI를 통하여 각각의 장비를 식별돼야 할 필요성이 있다. 본 논문에서는 RSSI 신호세기를 필터를 통하여 정렬하는 Zigbee Commissioning 기법을 제안한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.634-642
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• 2020

With the proliferation of Internet of Things (IoT) devices, using the Linux operating system in various architectures has increased. Also, security threats against Linux-based IoT devices are increasing, and malware variants based on existing malware are constantly appearing. In this paper, we propose a system where the binary data of a visualized Executable and Linkable Format (ELF) file is applied to Local Binary Pattern (LBP) image processing techniques and a median filter to classify malware in a Convolutional Neural Network (CNN). As a result, the original image showed the highest accuracy and F1-score at 98.77%, and reproducibility also showed the highest score at 98.55%. For the median filter, the highest precision was 99.19%, and the lowest false positive rate was 0.008%. Using the LBP technique confirmed that the overall result was lower than putting the original ELF file through the median filter. When the results of putting the original file through image processing techniques were classified by majority, it was confirmed that the accuracy, precision, F1-score, and false positive rate were better than putting the original file through the median filter. In the future, the proposed system will be used to classify malware families or add other image processing techniques to improve the accuracy of majority vote classification. Or maybe we mean "the use of Linux O/S distributions for various architectures has increased" instead? If not, please rephrase as intended.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.11
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• pp.403-408
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• 2014

In the Internet of Things(IoT) era, many of the things or objects that enclose our environments are able to associate with those things on the Internet. To construct IoT systems, it needs to consider a component for acquiring and aggregating of sensory data via things with sensors and instruments, which is connected by diverse networks, in IoT environment. An IoT system is intrinsically distributed in a variety of ways. In addition, to manage an IoT system efficiently, interoperability is needed to meet requirements while the IoT system is designed to deliver data among its applications. In this paper, a reference architecture based on asynchronous messaging is defined and used for designing an IoT system. To apply the architecture, we discuss how to manage data streams with real-time characteristics and make a prototype based on pipe-and-filter to produce and consume them by a pub/sub messaging system NaradaBrokering.

• Journal of Internet of Things and Convergence
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• v.5 no.1
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• pp.29-34
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• 2019

A bag filter collector is a kind of air purifier that organizes several or dozens of filters to purify fine dust and release clean air into the atmosphere. If the bag filter length is less than 5m, the dust and fume attached to the bag filter could be effectively removed by passing the compressed air generated by the diaphragm valve through the venturi. Injectors that are more efficient and economical are urgently needed to achieve satisfactory results for long-bag exhaustion of more than 7 meters. In the case of existing domestic and foreign injectors, a number of blow tubes were dismantled during maintenance, and the injector and blow tube were combined to pose a number of problems, including inconvenience of work due to weight increase. In this study, injector flow for the development of the best use of interpretation of the coanda effect and the fourth round of industrial technology Intelligent automation of exhaustion, have been engineered energy than standard equipment. lowering costs and filter life to radically improve the commercial studies.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.271-278
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• 2021

This paper is a study on the implementation of smart filter system that recognizes the external environment and automatically removes pollutants according to pollution level. Recently, the occurrence of various pollutants in indoor and outdoor space has adversely affected the human body. Especially, various fine dust generated in the atmosphere becomes worse in closed residential space or office space. Although air pollution can be temporary lowered through ventilation, it is difficult to respond to fine dust changes in real time, and such problems become serious in the space where many people reside, such as at home or industry. Therefore, it is necessary to measure the pollution level of fine dust inside the residential space in real time and to reduce the pollution of indoor ventilation through automatic ventilation with the outside. To improve these problems, this paper proposes the implementation of smart filter system for external environment recognition. The structure of smart filter system that automatically measures air quality inside and outside, removes pollutants, implements the function, and confirms the operability by manufacturing prototypes. Finally, the effectiveness of the smart filter system for solving fine dust problems was examined.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.7
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• pp.313-318
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• 2016

To utilize sensory data, it is necessary to design architecture for processing and handling data generated from sensors in an IoT environment. Especially in the IoT environment, a thing connects to the Internet and efficiently enables to communicate a device with diverse sensors. But Hadoop and Twister based on MapReduce are good at handling data in a batch processing. It has a limitation for processing stream data from a sensor in a motion. Traditional streaming data processing has been mainly applied a MoM based message queuing system. It has maintainability and scalability problems because a programmer should consider details related with complex messaging flow. In this paper architecture is designed to handle sensory data aggregated The designed software architecture is used to operate an application on the open source framework Storm. The application is conceptually used to transform streaming data which aggregated via sensor gateway by pipe-filter style.

• Journal of IKEEE
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• v.19 no.2
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• pp.142-147
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• 2015

In this paper, a Kalman filter-based sensor fusion filter that measures posture by calibrating and combining information obtained from acceleration and gyro sensors was proposed. Recent advancements in sensor network technology have required sensor fusion technology. In the proposed approach, the nonlinear system model of the filter is converted to a linear system model through a Jacobian matrix operation, and the measurement value predicted via Euler integration. The proposed filter was implemented at an operating frequency of 74 MHz using a Virtex-6 FPGA Board from Xilinx Inc. Further, the accuracy and reliability of the measured posture were validated by comparing the values obtained using the implemented filters with those from existing filters.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.1
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• pp.183-190
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• 2021

This study is a study on the implementation and operation of smart air cleaning system to improve indoor air quality. Recently, the problem of indoor air quality is getting serious due to various environmental factors. In this study, to improve the problems of indoor air quality, we implement an air cleaning system using IoT sensor. In particular, we proposed a system that can measure air pollution in real time and change different air flow paths according to pollution level. Through this, we examined efficient air quality improvement, extension of filter life, and system energy reduction. In addition, the main functions of the indoor air quality improvement system were constructed and prototypes were manufactured to confirm the operability. Finally, the utility of fine dust resolution through the implementation of the indoor air quality improvement system was examined.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.491-494
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• 2018

Radio base stations, which are widely distributed across large areas, have many difficulties in managing them. Unmanned radio base stations in remote mountains are having a hard time accessing them in case of emergencies. Major telephone service providers only remotely control incoming and outgoing information and local small business partners responsible for maintaining actual facilities do not possess such technologies, so they are each checked during field visits. In this study, in order to monitor temperature, humidity, fire condition, and power operation at a wide range of radio base stations, real-time monitoring is carried out at the office of Klaus server through real-time monitoring.