• Journal of IKEEE
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• v.26 no.1
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• pp.62-66
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• 2022

Recently, there have been many research efforts based on data-based deep learning technologies to deal with the interference problem between heterogeneous wireless communication devices in unlicensed frequency bands. However, existing approaches are commonly based on the use of complex neural network models, which require high computational power, limiting their efficiency in resource-constrained network interfaces and Internet of Things (IoT) devices. In this study, we address the problem of classifying heterogeneous wireless technologies including Wi-Fi and ZigBee in unlicensed spectrum bands. We focus on a data-driven approach that employs a supervised-learning method that uses received signal strength indicator (RSSI) data to train Deep Convolutional Neural Networks (CNNs). We propose a simple measurement methodology for collecting RSSI training data which preserves temporal and spectral properties of the target signal. Real experimental results using an open-source 2.4 GHz wireless development platform Ubertooth show that the proposed sampling method maintains the same accuracy with only a 10% level of sampling data for the same neural network architecture.

• Journal of Internet of Things and Convergence
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• v.10 no.2
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• pp.125-130
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• 2024

With the rapid growth of mobility technology, the industrial sector is demanding storage devices that can reliably process data from various equipment and sensors in vehicles. NAND flash memory is being utilized as a storage device in mobility environments because it has the advantages of low power and fast data processing speed as well as strong external shock resistance. However, flash memory is characterized by data corruption due to long-term exposure to high temperatures. Therefore, a dedicated system for temperature management is required in mobility environments where high temperature exposure due to weather or external heat sources such as solar radiation is frequent. This paper designs a dedicated temperature management system for managing storage device temperature in a mobility environment. The designed temperature management system is a hybrid of traditional air cooling and water cooling technologies. The cooling method is designed to operate adaptively according to the temperature of the storage device, and it is designed not to operate when the temperature step is low to improve energy efficiency. Finally, experiments were conducted to analyze the temperature difference between each cooling method and different heat dissipation materials, proving that the temperature management policy is effective in maintaining performance.

• Journal of Internet of Things and Convergence
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• v.9 no.2
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• pp.41-46
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• 2023

Smart factory construction projects are continuously being carried out domestically and abroad. In particular, in times of increasing uncertainty, interest in smart factories is increasing to improve corporate productivity. Currently, the government-led smart factory construction project is continuously being promoted in Korea. The tangible results of this construction project are very positive in indicators such as productivity improvement, quality improvement, and cost reduction. On the other hand, various contents are revealed in the survey to identify operational difficulties after building a smart factory. In this study, we analyzed difficulties (problems) in operation after establishing the system shown in the survey conducted in 2017 and 2020, and derived improvement plans for them. If these improvement measures are implemented in the relevant process of the smart factory construction project, it is expected that the operational difficulties felt by companies will be reduced, and a system with higher satisfaction than before will be established.

• Journal of Internet of Things and Convergence
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• v.6 no.3
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• pp.15-20
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• 2020

In this paper, an error tracking platform is designed for enhanced-reliable IOT system. The platform is designed to enhance reliability of IOT system by analysing additional informations(OS, Browser, Device) and by notifying error detection to developers. Especially, in the case of an error in the service which it is difficult for developers to recognize it, The platform also supports notification services through various communication media(Email, Slack, SMS). The common interface is designed to accommodate many languages(typescript, Swift, and Android) in the development process, and the interface allows users to analyze errors that occur on various platforms, including mobile/web/desktop applications. By presenting each error in groups through issues, developers can easily identify issues in the service. The visualizing function is included to recognize various error type by dashboard.

• KIISE Transactions on Computing Practices
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• v.23 no.7
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• pp.434-439
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• 2017

More and more people are suffering from sleep disturbance, which can have many different causes. The healthcare industry, which can help people with this disability, is one technology that is currently in the spotlight. However, current services are vulnerable to data concentration, because they are simple telemedicine services that transmit all data to a remote server and process the data on the server. They have a disadvantage in that the data cannot be streamed in real time by synchronizing the biometric data of remotely protected persons. In order to solve this problem, we propose a service structure for streaming biometric data of protected persons to a hospital or guardian in real time, using a self-organizing distributed middleware platform without a central server. We prove that it is possible to provide an effective streaming service by evaluating the service start time and average delay time.

• Journal of Internet of Things and Convergence
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• v.7 no.1
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• pp.71-77
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• 2021

As the IOT technology has developed, it becomes more big issues about IOT device security. An account management is a nerve-in-the-box routine job for the system administrator and users who manage the several hundreds IOT devices(IP camera, Home IOT, the various measuring equipment). This study is to propose the account management system by the hierarchical design and it is efficient for the user to manipulate the account management. The designed system supports 6 functions for the account management and apply the advanced technologies for the existed system. After the performance of the designed system is validated successfully by the authoritative test, the designed system is applied for the relative fields. And it is on going for the development of the smart account management system by applying the AI technique.

• Journal of Internet of Things and Convergence
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• v.1 no.1
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• pp.39-44
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• 2015

Organization is increasing the authorizing process to use public certificate and bio information. Certificate, has evolved to be able to parallel distributes the bio authentication and portable bio-authentication device. Authentication using an individual's PC and smart devices continue to generalize, while convenience for authentication is increased by comparison Study on cooperation with the security at the network level's a weak situation. If ask authentication method through the cooperation of the public certificate and bio information work with current network access control, there is a possibility to develop a more powerful security policy. by cooperation weaknesses against vulnerable personal authentication techniques on security token in a reliable and secure personal authentication techniques, such as bio-recognition, Bio Information for identification and to prevent exposing a methodology suggest to validate whether or not to carry out in this paper. In addition, organize the scenario that can work with the 802.1x network authentication method, and presented a proposal aimed at realization.

• Food Science and Industry
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• v.54 no.3
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• pp.124-131
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• 2021

In the 4th industrial revolution, Artificial Intelligence (AI), big data, Internet of Things (IoT) are already around us, making our society hyper-connected and blurring the lines between the digital and biological spheres. We witness drastic changes not only in the food industry, but also in economy, society and our life as a whole. Technologies bring industrial reorganization and greater changes at the system level and the food industry is not exceptional. Human demand for foods continues to grow and the very nature of the food industry remains unchanged, but its production, distribution and marketing face unprecedent innovations. Passing through the global pandemic, the food industry has been evolved into 'contact-free', as the safety become our top priority. Amid the gradual shift to technology-oriented society, the smarter food safety management skills and tools are being adopted in many countries exerting greater efforts to enhance traceability and to upgrade AI-powered safety management system.

• Journal of the Korean Institute of Gas
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• v.24 no.5
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• pp.10-19
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• 2020

Valve leak accidents in petrochemistry plants and gas utilities cause human and property damage. The main reason why happen gas inhalation, poisoning, fire and explosion accidents is gas valve leakage. To prevent gas leakage, inspectors check the facilities in the field. And they are at risk of gas leak accidents. So we applied IoT-based risk assessment, monitoring and automatic control system. It can detect both internal and external gas leakage, do real-time monitoring of industrial valve in the plant by using hybrid sensor. As the new safety management system for industrial valve is developed, it needs method to evaluate device performance and environmental components for the system. This study is about development of method to verify performance of the explosion-proofed hybrid sensing system include gas detector and optical fiber sensor supporting wire and wireless communication.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.2
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• pp.41-56
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• 2019

Cloud manufacturing is a new concept of manufacturing process that works like a single factory with connected multiple factories. The cloud manufacturing system is a kind of large-scale CPS that produces products through the collaboration of distributed manufacturing facilities based on technologies such as cloud computing, IoT, and virtualization. It utilizes diverse and distributed facilities based on centralized information systems, which allows flexible composition user-centric and service-oriented large-scale systems. However, the cloud manufacturing system is composed of a large number of highly heterogeneous subsystems. It has difficulties in interconnection, data exchange, information processing, and system verification for system construction. In this paper, we derive the user requirements of various aspects of the cloud manufacturing system, such as functional, human, trustworthiness, timing, data and composition, based on the CPS Framework, which is the analysis methodology for CPS. Next, by analyzing the user requirements we define the system requirements including scalability, composability, interactivity, dependability, timing, interoperability and intelligence. We map the defined CPS system requirements to the requirements of oneM2M, which is the platform standard for IoT, so that the support of the system requirements at the level of the IoT platform is verified through Mobius, which is the implementation of oneM2M standard. Analyzing the verification result, finally, we propose a large-scale cloud manufacturing platform based on oneM2M that can meet the cloud manufacturing requirements to support the overall features of the Cloud Manufacturing CPS with dependability.