• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.829-835
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• 2017

Recently, the health issues triggered by fine dust matters occurred in higher frequency. Having adverse effects on health, particulate matters affect the human body indoors as well as outdoors. There is thus a need for a system to measure the concentration of particulate matters and control harmful particulate matters for human health in the indoor spaces where people live. The present study applied Internet of Things(IoT) technologies in order to increase the efficiency of the conventional fine dust measurement system. Especially, for the bidirectional communication environment, directly construct a separate server and applied to the system instead of a free cloud server also we used it directly in the school lab and home. When the proposed system is used in schools and homes, it can recognize the indoor environment quickly and it is expected that this will gradually contribute to the health of the individual. Users can also check the server data outside and deal with the current indoor situations.

• The KIPS Transactions:PartD
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• v.10D no.1
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• pp.153-160
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• 2003

Recently, deployments of firewalls and NATs ire increasing to provide network security features or to solve the problem of public IP shortage. But, in these environments, peers in different firewall or NAT environments may get limited services because they cannot open direct communicate channels. This can be a significant problem in pure P2P environments where the peers should get or provide services by opening direct channels among themselves. In this paper, we propose a scheme for dynamically selecting a peer that fan be used as a proxy server. The proxy server supports the communication between the peers in different firewall or NAT environments. The proposed scheme is operating system independent and supports bidirectional communication among the peers in P2P environments. Additionally, the proposed scheme can distribute network traffic by dynamically allocating proxy servers to the peers that is not located in the firewall or NAT environments.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.4
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• pp.23-31
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• 2018

This paper presented the implementation and design of the 2T-2R wireless HD video streaming systems over 1.7 GHz frequency band using 3GPP LTE-TDD standard on NI USRP RIO SDR platform. The baseband of the system used USRP RIO that are stored in Xilinx Kintex-7 chip to implement LTE-TDD transceiver modem, the signal that are transmitted from USRP RIO up or down converts to 1.7 GHz by using self-designed 1.7 GHz RF transceiver modules and it is finally communicated HD video data through self-designed 2x9 sub array antennas. It is that communication method between USRP RIO and Host PC use PCI express x4 to minimize delay of data to transmit and receive. The implemented system show high error vector magnitude performance above 32 dBc and to transmit and receive HD video in experiment environment anywhere. The proposed hybrid beam forming system could be used not only in the future 5G mobile communication systems under 6 GHz frequency band but also in the systems over 6 GHz frequency band like ones in mmWave frequency bands.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.157-163
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• 2013

The development of the latest media technology has changed the traditional broadcasting system. The traditional broadcasting system, which was operated by the mass media and the terrestrial broadcasters, is now transformed to the viewer-centered and bidirectional media through the convergence of internet and mobile. In terms of broadcasting environment, the function of the traditional TVs has been changed to the Smart TVs combined with an open platform which not only deliver visual contents, but also supply various applications and additional information linking the content providers and viewers. This ongoing broadcasting environmental change has made it possible for viewers to participate in the programs such as reality shows or sports events through SNS, texting or phone calls. Therefore, the purpose of this experiment is to present the ways to promote easier and more convenient viewer-participation in the programs by applying mobile messenger to existing broadcasting system in order to enhance the involvement of broadcasters and viewers of the programs and to diversify the roles of content providers and viewers in broadcasting.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.10
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• pp.1949-1954
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• 2016

Smart grid technology can be called grid techniques to improve the efficiency of the electric power by exchanging bidirectional information of electric power with real-time between electric power suppliers and consumers. Recently, the solar power generation system is being applied actively. However the solar power system has several problems leading to reduce overall electricity generation, because the difficult of the diagnosis and the solar power system failure such as PV(PhotoVoltaics) and inverter. In order to build an efficient smart grid, a stable electric power energy requirements capture and management and early fault detection is essentially required in solar power generation system. In this paper, it is designed to monitor the operating status of the solar power monitoring system from a remote location through a RS-485 or TCP/IP communication module to monitoring the output of solar power energy and abnormal phenomenon, to developing the measurement module and to transfer measured data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.2C
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• pp.57-64
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• 2011

A two-way relay channel is a bidirectional cooperative communication channel between two nodes using a relay. In many cooperative communication schemes, a relay transmits its data to each node using separate channels. However, in the two-way relay channel, a relay can broadcast the network-coded signal to both nodes in a same time slot, which can increase the system throughput. In this paper, a new cooperative network error correcting scheme using distributed turbo code in a two-way relay channel is proposed. The proposed scheme not only increases the system throughput using network code but also improves the performance by utilizing the LLR information from relay node and other user node through distributed turbo code. Also, a power allocation scheme is investigated for various channel conditions to improve the system performance.

• Journal of Korea Society of Industrial Information Systems
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• v.5 no.3
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• pp.117-124
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• 2000

A systolic array is a parallel processing system which consists of processing elements of basic computation capabilities, connected with regular and local communication lines. It has been known that a systolic array is on of effective systems to solve complicated communication problems occurred between densely connected neurons on ANN(Artificial Neural Network). In this paper, a systolic array simulator for the back-propagation ANN, which automatically constructs the proper systolic array for a given number of neurons of the ANN, is designed and constructed. With animation techniques of the simulators, it is easy for users to be able to examine the execution of the back-propagation algorithm on the designed systolic array step by step. Moreover the simulator can perform forward and backward operations of the back-propagation algorithm either in sequence or in parallel on the designed systolic array. Parallel execution can be performed by feeding continuous input patterns and by executing bidirectional propagations on all of processing elements of a systolic array at the same time.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.617-624
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• 2022

The small electric vehicles equipped with V2X(vehicle to everything) systems may provide more information and function to the existing navigation system of the vehicle. The key components of V2X technology include V2V (vehicle to vehicle), V2N(vehicle to network) and V2I (vehicle to infrastructure). This study is to design and implementation of VI type E-PTO which is interfaced with external equipments, the work designs the components of E-PTO such as DC/DC converter, DC/AC converter, battery bidirectional charging system etc. Also, it implements the devices and control systems for driving. The test results of VI type E-PTO components showed allowable 10% requirements of transient voltage variation rate and recovery time within 100ms for start/stop and normal operation.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.3
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• pp.571-576
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• 2024

Ontologies are created by domain experts, but the same content may be expressed differently by each expert due to different understandings of domain knowledge. Since the ontology standardization is still lacking, multiple ontologies can be exist within the same domain, resulting in a phenomenon called the ontology heterogeneity. Therefore, we propose a novel ontology matching method that combines SCBOW(: Siames Continuois Bag Of Words) and BERT(: Bidirectional Encoder Representations from Transformers) models to solve the ontology heterogeneity issue. Ontologies are expressed as a graph and the SimRank algorithm is used to solve the one-to-many problem that can occur in ontology matching problems. Experimental results showed that our approach improves performance by about 8% over traditional matching algorithm. Proposed method can enhance and refine the alignment technology used in ontology matching.

• Journal of the Korea Society of Computer and Information
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• v.29 no.5
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• pp.143-153
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• 2024

This study aims to analyze both the current utilization of e-learning in the scuba diving education sector and the possible improvements by using Delphi analysis. The study administered three rounds of Delphi surveys with 25 specialists, including business executives and educational leaders from scuba diving centers and resorts affiliated with organizations that conduct scuba diving education through e-learning. The comparative analysis of the state of e-learning utilization and factors for improvement revealed significant insights. In terms of expected benefits, the analysis highlighted an increase in user convenience, temporal flexibility in learning activities, and easy access to products. However, it identified major issues such as the simplistic mandatory exams, inadequate professional depth in the feedback provided, and a lack of bidirectional communication between learners and instructors. Recommendations for improvements included enhancing communication through various online communities, conducting mandatory exams offline, and developing a variety of content. Conducting regular program quality evaluations, integrating with various diving communities, and assigning dedicated tutors were deemed crucial factors for future development.