• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.1055-1058
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• 2011

• Journal of the Korean Society of Industry Convergence
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• v.4 no.4
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• pp.441-450
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• 2001

This dissertation deal with over-all wireless communication technology. And introduce wireless communication technology analytically that it use for Home-LAN communication technology (HomeRF, Bluetooth, IEEE 802.11, HIPERLAN, etc). Home-LAN communications issue by the terminal field of the latest high-speed network construction. This technologies possesses characteristics and significances as the representative technology using in Home-LAN communication technology. Also, the method of application is conditional on individually. Wireless LAN put Home-LAN communications to practical use. Bluetooth have practical use for an individual mobile communications with internet. HomeRF have a vision that the construction of wireless system in house purely. Therefore, this dissertation investigates merits and demerits between those technologies. And then leads the most compatible technology for application of Home-LAN. Finally, this thesis have a view of the development course hereafter.

• Economic and Environmental Geology
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• v.41 no.2
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• pp.267-273
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• 2008

This study was carried out to seek communication programs of geo-technology R&D outcome. For this, the following questions were set. 1) How much portion do KIGAM as the main body of geo-technology R&D among articles reported by major newspapers? 2) What are strength, weakness, opportunity, and threat factors of geo-technology R&D outcome from the communication view point? 3) What is the communication tasks and the communication ways for them? In conclusion, the communication programs of geo-technology R&D outcome using SMTCR(Sender-Message-Tool-Channel-Receiver) model were suggested.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.8
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• pp.4227-4240
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• 2019

In this paper, we present our proposed magnetic induction based wireless communication system. The proposed system is designed to perform communication as well as distance measurement in underground environments. In order to improve the communication quality, we propose and implement the adaptive channel compensation technique. Based on the fact that the channel may be fast time-varying, we keep track of the channel status each time the data is received and accordingly compensate the channel coefficient for any change in the channel status. By using the proposed compensation technique, the developed platform can reliably communicate over distances of 10m while the packet error rate is being maintained under 5%. We also implement the distance measurement block that is useful for various applications that should promptly estimate the location of nearby nodes in communication. The distance between two nodes in communication is estimated by generating a table describing pairs of the magnetic signal strength and the corresponding distance. The experiment result shows that the platform can estimate the distance of a node located within 10m range with the measurement error less than 50cm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.8
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• pp.2736-2750
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• 2022

As demands for the maritime communications increase, a variety of functions and information are required to exchange via elements of maritime systems, which leads communication traffic increases in maritime frequency bands, especially in VHF (Very High Frequency) band. Thus, effective resource management is crucial to the future maritime communication systems not only to the typical terrestrial communication systems. VHF data exchange system (VDES) enables to utilize more flexible configuration according to the communication condition. This paper focuses on the VDES communication system among VDES terminals such as shore stations, ship stations and aids to navigation (AtoN) to address efficient resource allocation. We propose a resource management method considering a MIMO (Multiple Input Multiple Output) technique in VDES, which has been widely used for modern terrestrial wireless networks but not for marine environments by scheduling the essential communication resources. We introduce the general channel model in marine environment and give two metrics, spectral and the energy efficiencies to examine our resource scheduling algorithm. Based on the simulation results and analysis, the proposed method provides a possibility to enhance spectral and energy efficiencies. Additionally, we present a trade-off relationship between spectral and energy efficiencies. Furthermore, we examine the resource efficiencies related to the imperfect channel estimation.

• Journal of the Semiconductor & Display Technology
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• v.13 no.3
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• pp.21-25
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• 2014

The texturing is one of the most important processes for high efficiency crystalline silicon solar cells. The rear side flatness of silicon solar cell is very important for increasing the light reflectance and forming uniform back surface field(BSF) region in manufacturing high efficiency crystalline silicon solar cells. We investigated texturing difference between front and rear side of wafer by texturing of two adhered wafers. As a result, the flatter rear side was obtained by forming less pyramid size compared to the front side and improved reflectance of long wavelength and back surface field(BSF) region were also achieved. Therefore, the texturing of two adhered wafers can be expected to improve the efficiency of silicon solar cells due to increased short circuit current(Isc).

• Korean Management Science Review
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• v.10 no.1
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• pp.1-22
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• 1993

Systemetic classification of a technology is critical to the development of technology strategy. This paper suggests a new technology classification scheme for computer and communication : a two-level scheme. Technology is first classified by its role and function in the upper level which forms a 2 * 2 matrix. The technology is then further classified into the lower level of 3 classes by associations among technology elements. Thus, a new classification scheme of 2 * 2 * 3 matrix is proposed for the computer and communication technology.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1634-1637
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• 2004

We developed a communication device for person with serious disability to use slight movement. This device is developed mainly for patients suffering from ALS or a cerebral infarction. They often have communication difficulty because of deterioration of muscle functions. A feature of this device is that slight movements of user's finger, eyes or lips can be detected by using a vision sensor. Due to the features of the vision sensor, it is quite easy even for person with serious disability to use a communication device. By the field test it is confirmed that the vision sensors have superior performances as an input device for communication device. Experiments to use an EMG (electromyography) sensor and a rotary sensor are also tested to compare the performances.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.5
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• pp.608-614
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• 2018

In addition to the diffusion of ICT technology, various protocols of short range wireless communication technology are being applied for efficient information operation. However, due to limitations of short-range wireless communication, communication is not smooth in places where frequency environment is poor, such as frequency confusion and warehouse type factory. When an alternative is needed. The development of LED technology and expansion of infrastructure through LED based visible light communication is attracting attention as an alternative and spreading the usage in wide range now a days. In addition, the infrastructure has been expanded with solar panels in response to the development of smarthome built-in with renewable energy. In this situation, visible light communication using PD has been limitedly applied in a near environment where the receiving angle of the PD and the ambient light ensure the LoS and the influence of the ambient light is small. In order to solve this problem, we have implemented visible light communication using LED lighting with large current infrastructure and solar panel with large receiving area, and proposed a circuit for restoring accurate data even in ambient light. Through this study results, it is expected that visible light communication can be more widely used and this result used as the base data for visible light communication research using the solar panel as the receiver.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2795-2803
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• 2011

Due to speed acceleration, higher requirements have been put forward to high speed railway communication and signaling system. The railway applications, including intra-train, train to ground and trackside networks, demand larger bandwidth, higher reliability and shorter response time from railway communication networks to ensure security operation and passenger communication. However, the current railway communication and signaling system has lagged behind the railway development, so advanced communication technologies are needed to improve the current situation. This paper presents high speed railway communication and signaling system based on 4G LTE technology, introduces its network architecture, key technology and analyzes its technical advantages compared with GSM-R system. According to analysis, LTE based high-speed railway communication network is more effective and reliable.