• Journal of the Korea Society of Computer and Information
• /
• v.14 no.10
• /
• pp.101-110
• /
• 2009

The 6LoWPAN(IPv6 Low-power Wireless Personal Area Network) performs IPv6 header compression, TCP/UDP/IGMP header compression, packet fragmentation and re-assemble to transmit IPv6 packet over IEEE 802,15.4 MAC/PHY. However, from the point of view of security. It has the existing security threats issued by IP packet fragmenting and reassembling, and new security threats issued by 6LoWPAN packet fragmenting and reassembling would be introduced additionally. If fragmented packets are retransmitted by replay attacks frequently, sensor nodes will be confronted with the communication disruption. This paper analysis security threats introduced by 6LoWPAN fragmenting and reassembling, and proposes a re-transmission mechanism that could minimize re-transmission to be issued by replay attacks. Re-transmission procedure and fragmented packet structure based on the 6LoWPAN standard(RFC4944) are designed. We estimate also re-transmission delay of the proposed mechanism. The mechanism utilizes timestamp, nonce, and checksum to protect replay attacks. It could minimize reassemble buffer overflow, waste of computing resource, node rebooting etc., by removing packet fragmentation and reassemble unnecessary.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.26 no.11
• /
• pp.1706-1712
• /
• 2022

Recently, the safety of chemical substances has gained attention due to incidents occurring in petrochemical industrial complexes, such as gas leaks and fires. In particular, industrial complexes in Ulsan and Yeosu (South Korea) are valuable as they significantly contribute to the petrochemical industry, but accidents may occur due to chemical leakage. Therefore, in this study, sensor nodes are configured at an interval of 20 [m] based on outdoor facilities standards to respond to chemical accidents, and exposure consideration of 8 h (TWA) and 15 min (STEL) are proposed in TLVs. The proposed system pre-processes data collected in multi-hop communication at a cycle of 0.6-0.75 [s] using Python and stores it in the MySQL database through SQL and a real-time remote monitoring system that updates the stored data once every 5 s is implemented by linking MySQL and Grafana.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.18 no.4
• /
• pp.826-842
• /
• 2024

As 5G and AI continue to develop, there has been a significant surge in the healthcare industry. The COVID-19 pandemic has posed immense challenges to the global health system. This study proposes an FL-supported edge computing model based on federated learning (FL) for predicting clinical outcomes of COVID-19 patients during hospitalization. The model aims to address the challenges posed by the pandemic, such as the need for sophisticated predictive models, privacy concerns, and the non-IID nature of COVID-19 data. The model utilizes the FATE framework, known for its privacy-preserving technologies, to enhance predictive precision while ensuring data privacy and effectively managing data heterogeneity. The model's ability to generalize across diverse datasets and its adaptability in real-world clinical settings are highlighted by the use of SHAP values, which streamline the training process by identifying influential features, thus reducing computational overhead without compromising predictive precision. The study demonstrates that the proposed model achieves comparable precision to specific machine learning models when dataset sizes are identical and surpasses traditional models when larger training data volumes are employed. The model's performance is further improved when trained on datasets from diverse nodes, leading to superior generalization and overall performance, especially in scenarios with insufficient node features. The integration of FL with edge computing contributes significantly to the reliable prediction of COVID-19 patient outcomes with greater privacy. The research contributes to healthcare technology by providing a practical solution for early intervention and personalized treatment plans, leading to improved patient outcomes and efficient resource allocation during public health crises.

• Journal of Internet Computing and Services
• /
• v.25 no.4
• /
• pp.1-6
• /
• 2024

OMNeT++ (Objective Modular Network Testbed in C++) is an extensible and modular C++ simulation library and framework for building network simulators. OMNeT++ provides simulation models independently developed for various fields, including sensor networks, and Internet protocols. This enables researchers to use the tools and features required for their desired simulations. OMNeT++ uses NED (Network Description) Language to define nodes and network topologies, and it is able to implement the creation and behavior of defined network objects in C++. Moreover, the INET framework is an open-source model library for the OMNeT++ simulation environment, containing models for various networking protocols and components, making it convenient for designing and validating new network protocols. This paper aims to explain the concepts of OMNeT++ and the procedures for network simulation using the INET framework to assist novice researchers in modeling and analyzing various network scenarios.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.19 no.5
• /
• pp.1013-1018
• /
• 2024

This study developed and evaluated a real-time monitoring system utilizing IoT technology to prevent disasters caused by hazardous gases in industrial settings. The developed system detects harmful gases in real-time and issues prompt alerts, achieving over 98% data accuracy and response times under 3 seconds. The system consists of sensor nodes, a central processing unit, and a user interface, monitoring the work environment and worker status in real-time through a cloud-based remote surveillance and control program. Performance evaluation results show that this system presents a new approach for effectively managing safety in industrial sites. Future developments are expected to include improvements in multi-gas detection capabilities, development of AI-based prediction models, and enhanced security measures, evolving into a more advanced monitoring system.

• Journal of Internet Computing and Services
• /
• v.23 no.5
• /
• pp.145-154
• /
• 2022

Automatic Target Recognition (ATR) technology is emerging as a core technology of Future Combat Systems (FCS). Conventional ATR is performed based on IMINT (image information) collected from the SAR sensor, and various image-based deep learning models are used. However, with the development of IT and sensing technology, even though data/information related to ATR is expanding to HUMINT (human information) and SIGINT (signal information), ATR still contains image oriented IMINT data only is being used. In complex and diversified battlefield situations, it is difficult to guarantee high-level ATR accuracy and generalization performance with image data alone. Therefore, we propose a knowledge graph-based ATR method that can utilize image and text data simultaneously in this paper. The main idea of the knowledge graph and deep model-based ATR method is to convert the ATR image and text into graphs according to the characteristics of each data, align it to the knowledge graph, and connect the heterogeneous ATR data through the knowledge graph. In order to convert the ATR image into a graph, an object-tag graph consisting of object tags as nodes is generated from the image by using the pre-trained image object recognition model and the vocabulary of the knowledge graph. On the other hand, the ATR text uses the pre-trained language model, TF-IDF, co-occurrence word graph, and the vocabulary of knowledge graph to generate a word graph composed of nodes with key vocabulary for the ATR. The generated two types of graphs are connected to the knowledge graph using the entity alignment model for improvement of the ATR performance from images and texts. To prove the superiority of the proposed method, 227 documents from web documents and 61,714 RDF triples from dbpedia were collected, and comparison experiments were performed on precision, recall, and f1-score in a perspective of the entity alignment..

• KIPS Transactions on Computer and Communication Systems
• /
• v.6 no.11
• /
• pp.437-444
• /
• 2017

Electric Pole is a supporting beam used for power transmission/distribution which is sensitive to external force change of environmental factors. Therefore, power facilities have many difficulties in terms of maintenance/conservation from external environmental changes and natural disasters that cause a great economic impact. The aerial wire cause elasticity due to the influence of temperature, or factors such as wind speed and wind direction, that weakens the electric pole. The situation may lead to many safety risk in day-to-day life. But, the safety assessment of the pole is carried out at the design stage, and aftermath is not considered. For the safety and maintenance purposes, it is very important to analyze the influence of weather factors on external forces periodically. In this paper, we analyze the acceleration data of the sensor nodes installed in electric pole for maintenance/safety purpose and use Kalman filter as noise compensation method. Fast Fourier Transform (FFT) is performed to analyze the influence of each meteorological factor, along with the meteorological factors on frequency components. The result of the analysis shows that the temperature, humidity, solar radiation, hour of daylight, air pressure, wind direction and wind speed were influential factors. In this paper, the influences of meteorological factors on frequency components are different, and it is thought that it can be an important factor in achieving the purpose of safety and maintenance.

• Journal of KIISE:Information Networking
• /
• v.34 no.3
• /
• pp.218-225
• /
• 2007

As the research on home network technologies, sensor network technologies, and ubiquitous network technologies makes rapid progresses, wireless ad-hoc network have attracted a lot of attention. A wireless mobile ad-hoc network is a temporary network formed by a collection of wireless mobile nodes without the aid of any existing network infrastructure or centralized administration, and it is suitable for ubiquitous computing environments. In this paper, we suggest an extension scheme of a wireless mobile ad-hoc network based on limited multiple paths source routing protocol. This scheme reduces the overhead of route re-establishment and re-registration by maintaining link/node non-disjoint multiple paths between mobile hosts in a wireless mobile ad-hoc network or a mobile host in a wireless mobile ad-hoc network and a base station supporting fixed network services. By maintaining multiple paths, our scheme provides short end-to-end delay and is reliable extension scheme of a wireless mobile ad-hoc network to a fixed network. In this paper, our simulations show that our scheme outperforms existing schemes with regards to throughput and end-to-end delay. Also we show that our scheme outperforms multi-paths approach using disjoint routes with regards to routing overhead.

• The KIPS Transactions:PartC
• /
• v.12C no.7 s.103
• /
• pp.1031-1038
• /
• 2005

As the research on home network technologies, sensor network technologies, and ubiquitous network technologies makes rapid progresses, wireless ad-hoc network have attracted a lot of attention. A wireless ad-hoc network is a temporary network formed by a collection of wireless mobile nodes without the aid of my existing network infrastructure or centralized administration, and it is suitable for ubiquitous computing environments. In this paper, we suggest an interconnection scheme between the wireless ad-hoc network environment based on multiple path source routing protocol and a Mobile-IP based network environment. This scheme reduces the overhead of route re-establishment and re-registration by maintaining multiple paths between the mobile host in wireless ad-hoc network and the base station in mobile-IP network. Also it puts the base station in charge of function that performs translation between wireless ad-hoc network packets and Mobile-IP packets, reducing the load of mobile hosts. In this paper, our simulations show that our scheme outperforms existing interconnecting schemes with regards to throughput and end-to-end delay Also we show that our scheme outperforms multi-paths approach using disjoint routes with regards to routing overhead.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.47 no.6
• /
• pp.10-21
• /
• 2010

In the cluster-tree network which covers wide area network and has many nodes for monitoring purpose traffic is concentrated around the sink. There are long transmit delay and high data loss due to the intensive traffic when IEEE 802.15.4 is adapted to the cluster-tree network. In this paper we propose Dynamic Channel Allocation algorithm which dynamically allocates channels to increase the channel usage and the transmission success rate. To evaluate the performance of DCA, we assumed the monitoring network that consists of a cluster-tree in which sensing data is transmitted to the sink. Analysis uses the traffic data which is generated around the sink. As a result, DCA is superior when much traffic is generated. During the experiment assuming the least amount of traffic, IEEE 802.15.4, has the minimum length of active period and 90% data transmission success rate. However DCA maintains 11.8ms of active period length and results in 98.9% data transmission success rate.