• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.9
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• pp.1687-1693
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• 2007

Advances in technologies of networking, chip integration, and embedded system have enabled sensor networks applicable to a wide range of areas. Sharing some common characteristics, sensor networks are thus diversified in features depending on their applications. An intelligent and digital home can be one area to establish a particular feature of sensor network. This paper proposes a composite sensor and control network, and discusses its applying to the next generation intelligent and digital home. Development results of the network and a test-bed as a virtual test environment are also presented. The proposed network can not only be efficiently applying to achieve new home intelligences but also provide a sound solution to maintenance and operations of home network or devices.

• International Journal of Computer Science & Network Security
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• v.21 no.6
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• pp.89-100
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• 2021

Smart Grid Network (SGN) is a next generation electrical power network which digitizes the power distribution grid and achieves smart, efficient, safe and secure operations of the electricity. The backbone of the SGN is information communication technology that enables the SGN to get full control of network station monitoring and analysis. In any network where communication is involved security is essential. It has been observed from several recent incidents that an adversary causes an interruption to the operation of the networks which lead to the electricity theft. In order to reduce the number of electricity theft cases, companies need to develop preventive and protective methods to minimize the losses from this issue. In this paper, we have introduced a machine learning based SVM method that detects malicious nodes in a smart grid network. The algorithm collects data (electricity consumption/electric bill) from the nodes and compares it with previously obtained data. Support Vector Machine (SVM) classifies nodes into Normal or malicious nodes giving the statues of 1 for normal nodes and status of -1 for malicious -abnormal-nodes. Once the malicious nodes have been detected, we have done a trust evaluation based on the nodes history and recorded data. In the simulation, we have observed that our detection rate is almost 98% where the false alarm rate is only 2%. Moreover, a Trust value of 50 was achieved. As a future work, countermeasures based on the trust value will be developed to solve the problem remotely.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.8
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• pp.2083-2100
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• 2023

The rise of Industry 5.0 has led to a smarter and more digital way of doing business, but with it comes the issue of user privacy and security. Only when privacy and security issues are addressed, will users be able to transact online with greater peace of mind. Thus, to address the security and privacy problems associated with industry blockchain technology, we propose a privacy protection scheme for online financial transactions based on verifiable ring signatures and blockchain by comparing and combining the unconditional anonymity provided by ring signatures with the high integrity provided by blockchain technology. Firstly, we present an algorithm for verifying ring signature based on distributed key generation, which can ensure the integrity of transaction data. Secondly, by using the block chain technique, we choose the proxy node to send the plaintext message into the block chain, and guarantee the security of the asset transaction. On this basis, the designed scheme is subjected to a security analysis to verify that it is completely anonymous, verifiable and unerasable. The protection of user privacy can be achieved while enabling online transactions. Finally, it is shown that the proposed method is more effective and practical than other similar solutions in performance assessment and simulation. It is proved that the scheme is a safe and efficient online financial transaction ring signature scheme.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.1
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• pp.1-9
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• 2022

The PoN (Proof of Nonce) distributed consensus algorithm basically uses a non-competitive consensus method that can guarantee an equal opportunity for all nodes to participate in the block generation process, and this method was expected to resolve the first trilemma of the blockchain, called the decentralization problem. However, the decentralization performance of the PoN distributed consensus algorithm can be greatly affected by the network transaction transmission delay characteristics of the nodes composing the block chain system. In particular, in the consensus process, differences in network node performance may significantly affect the composition of the congress and committee on a first-come, first-served basis. Therefore, in this paper, we presented a problem by analyzing the decentralization performance of the PoN distributed consensus algorithm, and suggested a fairness control algorithm using a learning-based probabilistic acceptance rule to improve it. In addition, we verified the superiority of the proposed algorithm by conducting a numerical experiment, while considering the block chain systems composed of various heterogeneous characteristic systems with different network transmission delay.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.155-156
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• 2022

Efficient operation of ships can transport cargo to ports safer and faster, and reduce fuel costs. Therefore, in this study, the pattern was analyzed using AIS data of ships passing near Busan Port, a representative port in Korea. The analysis of vessel traffic patterns was approached with a grid-based node generation method, which can be used for research such as optimal route and route prediction.

• Journal of Korea Multimedia Society
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• v.14 no.5
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• pp.658-668
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• 2011

Over the past decade, the improvement of communications technologies and the rapid spread of www (World Wide Web) have brought on the exponential growth of users using Internet and real time multimedia multicast services like video conferencing, tele-immersive virtual reality, and Internet games. The dense-wavelength division multiplexing (DWDM) networks have been widely accepted as a promising approach to meet the ever-increasing bandwidth demands of Internet users, especially in next generation Internet backbone networks for nation-wide or global coverage. A major challenge in the next generation Internet backbone networks based on DWDM technologies is the resolution of the multicasting RWA (Routing and Wavelength Assignment) problem; given a set of wavelengths in the DWDM network, we set up light-paths by routing and assigning a wavelength for each connection so that the multicast connections are set-upped as many as possible. Finding such optimal multicast connections has been proven to be Non-deterministic Polynomial-time-complete. In this paper, we suggest a new heuristic multicast routing and wavelength assignment method for multicast sessions called DVS-PMIPMR (Differentiated Virtual Source-based Priority Minimum Interference Path Multicast Routing algorithm). We measured the performance of the proposed algorithm in terms of number of wavelength and wavelength channel. The simulation results demonstrate that DVS-PMIPMR algorithm is superior to previous multicast routing algorithms.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.7
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• pp.442-453
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• 2007

A model-based integrated development tool for the development of USN application programs is proposed in this paper. The proposed tool has been implemented as a plug-in for Eclipse platform. The tool consists of Graphical User Interface, Modeler, Configuration Information Generator, Validity Checker, Source Code Generator and Templates Storage. Developers can implement USN applications from models of sensor networks using the tool. The developer can implement USN applications by automatic generation of execution code of each node in the sensor network after he/she designs a model of the sensor network. The configuration information of each node is automatically generated from the validated USN model. Then, the execution code is automatically generated using the configuration information and the predefined templates. Through the tool of this paper, developers can easily implement valid USN applications even if they do not know the details of low-level information. Also, a large number of application programs can be generated at once because application programs are generated from sensor network model instead of models of applications. Accordingly, the development effort of USN applications will be decreased and developers can consistently construct USN applications from USN models using the proposed tool.

• Reproductive and Developmental Biology
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• v.31 no.1
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• pp.1-6
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• 2007

The nonobese diabetic / severe combined immune deficiency (NOD/SCID) has been used for determination of proliferation and differentiation of hematopoietic stem cells as xenotransplantation animal model. In this study, we transplanted porcine hematopoietic cells from bone marrow into NOD/SCID mice via intravenous injection to confirm the activity of differentiation and proliferation for porcine hematopoietic cells in vivo. Interestingly, we observed the result of high efficiency with pig T lymphocytes in hematopoietic organs, liver, spleen lymph node, and bone marrow in NOD/SCID mice. The porcine $CD3^{+}$ T cells were detected with $5.4{\pm}1.9%$ in bone marrow, $15.4{\pm}7.3%$ in spleen, $21.3{\pm}1.4%$ in liver, and $33.5{\pm}32.8%$ in lymph node of NOD/SCID mice at 6 weeks after trans-plantation Furthermore, immunohistochemical analysis showed the high engraftment of porcine T lymphocytes in spleen of NOD/SCID mice. Our data suggest that NOD/SCID mice are excellent animal model to determinate the generation md function of pig T lymphocytes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8C
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• pp.633-641
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• 2008

Since WSNs encounter attacks, such as jamming or eavesdropping without physical access occurs, security is one of the important requirements for WSNs. The key pre-distribution scheme that was recently researched for advance of security in WSNs distributes the keys and probability with the use of q-composite random key pre-distribution method, but there is a high probability that no key shared between sensor nodes, and it takes a lot of time and energy to find out the shared key. Therefore, it is not suitable for WSNs. In order to enhance stability of a node that plays a role of gateway without depending on probabilistic key, this paper proposesa key pre-distribution scheme combined with random key pre-distribution scheme and double hash chain. Since the proposed scheme can maintain a small storage place and strong security strengths, it is more efficient than the existing schemes with the same security strengths. In addition, since it uses a small size of key generation key set, it can reduce a great deal of storage overhead.

• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.779-793
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• 1998

In this study, for the purpose of water supply planning, we propose a sophisticated multi-period mixed integer programming model that can coordinate the behavior of multi-reservoir operation, minimizing unnecessary spill. It can simulate the system with operating rules which are self- generated by the optimization engine in the algorithm. It is an optimization model in structure, but it indeed simulates the coordinating behavior of multi-reservoir operation. It minimizes the water shortfalls in demand requirements, maintaining flood reserve volume, minimizing unnecessary spill, maximizing hydropower generation release, keeping water storage levels high for efficient hydroelectric turbine operation. This optimization model is a large scale mixed integer programming problem that consists of 3.920 integer variables and 68.658 by 132.384 node-arc incidence matrix for 28 years of data. In order to handle the enormous amount of data generated by a big mathematical model, the utilization of DBMS (data base management system)seems to be inevitable. It has been tested with the Han River multi-reservoir system in Korea, which consists of 2 large multipurpose dams and 3 hydroelectric dams. We demonstrated successfully that there is a good chance of saving substantial amount of water should it be put to use in real time with a good inflow forecasting system.