• Journal of Korea Multimedia Society
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• v.18 no.6
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• pp.742-752
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• 2015

The communications through the power lines are called as the PLC and this is a common name for the communication modes for the information delivery. This technology transmits the data through the power lines on which the information is stored with the form of high frequency signal. The characteristic of the frequency signal is that the signal can be separated from the power line through exclusive power line modem and transmitted to the terminal devices. In this paper, 'In-home Headcount' checking algorithm using Wi-Fi and taking above mentioned advantages is proposed, and the basic Technology for such Solitary Senior Citizen's Lonely Death monitoring system has been designed and implemented. The comparative analysis has been conducted in this paper with the test-operated and test bed-completed 'Hyosimi 119 Safety-Welfare System' which is still being tested since 2008. With the 'In-home Headcount Checking Algorithm', Wi-Fi connection/disconnection status and SSIDs of relevant Wi-Fis will be checked. We expect that our proposed method will become as the basic Technology which can prevent lonely deaths of elderly people living alone. Since the PLC technology can be normally implement all the functions used on internet anticipate that the technology could be applied to many areas to construct a new form of communication network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.1016-1033
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• 2016

In this paper, we present a joint relay-and-antenna selection and power allocation strategy for multiple-input multi-output (MIMO) amplify-and-forward (AF) two-way relay networks (TWRNs). In our approach, we select the best transmit and receive antennas at the two sources, a best relay and a best transmit and receive antenna at the selected relay based on maximizing the minimum of the end-to-end received signal-to-noise-ratios (SNRs) under a total transmit power constraints. We obtained the closed-form solution for the optimal power allocation firstly. Then with the optimal allocation solution we found, we can reduce the joint relay-and-antenna selection to a simpler problem. Besides, the overall outage probability is investigated and a tight closed-form approximation is derived, which provides a method to evaluate the outage performance easily and fast. Simulation results are presented to verify the analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8C
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• pp.681-688
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• 2007

Applying an appropriate received signal processing algorithm based on the channel characteristics is important to improve the receiver performance. Wireless channels in general exhibit various time-delay characteristics depending on their power delay profile. When the estimated channel power summation is used to determine the amount of time delay, a channel adaptive receiver structure can be implemented. In this paper, we derive a closed-form expression for the error probability of the channel classification when the estimated channel power summation is used to classify channel groups having different time delay characteristics, and present the performance gain utilizing multiple estimation results.

• Journal of the Korean Wood Science and Technology
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• v.33 no.1 s.129
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• pp.97-110
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• 2005

This paper is the second part of a literature review describing the current status of biomass energy use in the USA. The bioenergy technologies that convert biomass resources to a form of energy were presented, in particular focused on existing coal fired boiler, high efficiency gasification combined cycle. We presented latest biomass power energy supply, economic issues such as its production and plant investment cost in the Part I. In the Part II, our review summarized policy and market issues for electricity consumers, benefits from biomass power which could offer an alternative to conventional energy sources in the form of environmental, rural economic growth, and national energy security in the USA.

• Journal of Power System Engineering
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• v.17 no.3
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• pp.57-64
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• 2013

This study focus on the analysis of the energy performance in accordance with apartment houses arrangement type by using Ecotect Analysis. Korea, energy-poor country, the rate of dependence on imports amount to 94%, have to reduce energy consumption part of building except in industry and transport which affect the economic. Apartment houses are built in various forms in order to reduce energy, are modelled in each window area ratio, shape, orientation, climate through simulation. Through this study, we can analyze energy performance by form, window area ratio, orientation, climate change and know the optimal elements by the form. In particular, although there have been studied research on the window area ratio and research related to the arrangement form, determined that the information on the regional climate characteristics and the direction of placement is less than existing research. To supplement those problem, adding to seven direction(West, S-60-W, S-30-W, South, S-30-E, S-60-E, East) and climatic element(southern region) is characteristic of this study. The form of apartment houses was modelled for apartment houses built in the 10 years since. And each modeling were analyzed by Ecotect Analysis.

• Journal of Power System Engineering
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• v.18 no.1
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• pp.45-50
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• 2014

This study focuses on the analysis of the cooling and heating load in accordance with apartment houses arrangement type using Ecotect Analysis. Korea have to reduce energy consumption part of building except in industry and transport because the rate of dependence on imports amounts to 94%, Apartment houses built in various forms in order to reduce energy are modelled in each window area ratio, shape, orientation, and climate through simulation. Through this study, we can analyze the cooling and heating load by form, window area ratio, orientation, and climate change and know the optimal elements by the form. In particular, although there have been done research on the window area ratio and the arrangement form, the research of the regional climate characteristics and the direction are hardly carried out. To supplement those problem, adding to seven direction and climatic element of southern region is characteristic(L Type, Y Type, - Type) of this study. The form of apartment houses built 10 years ago is modelled for simulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.4726-4732
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• 2013

The Domestic boat has been manufactured by hull form of typical foreign boat. In this study, design environment for polyethylene boat is analysed to create new hull form of the boat and design elements are extracted from existing boats and consumer preferences. Key elements in polyethylene boat design are three words "semi-classic, urban and sporty". Hull resistance and engine power for new developed boat can be expected by Orca 3D program. This result indicates that engine power of the boat is much less than that of commercial boat.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.8
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• pp.70-76
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• 2012

In this paper, we propose a power allocation scheme of the unlicensed user based on orthogonal frequency division multiplexing (OFDM) in the TV white space (TVWS). Power constraints in TVWS should be satisfied in the time domain. However, because OFDM has high PAPR (peak-to-average power ratio), it is difficult to satisfy power constraints of TVWS in the time domain. Furthermore, the conventional power allocation schemes cannot be generally applied to unlicensed user in TVWS. Therefore, we propose a power allocation scheme to satisfy power constraints of TVWS by reducing PAPR in the time domain. In addition, we analyze the capacity of the unlicensed user based on OFDM in a closed form. Based on the capacity analysis, as the number of subcarriers decreases, the capacity can be enhanced. In simulation results, we show that the capacity of the unlicensed user increases, as the number of subcarriers decreases and the mean of the channel between the transmitter and the receiver of the unlicensed user increases.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.1088-1094
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• 1997

An indirect cutting torque and cutting force estimation method is presented. This method uses a time-domain model between the spindle motor power, which calculated form measured spindle motor current and voltage. Spindle motor power is linear with cutting torque in this model. The cutting force is proportional to the cutting torque. Using trial cut, parameters are determined. Static sensitivity is suitable for various cutting conditions. The presented method is verified under several cutting tests on the CNC horizontal machining center.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.10a
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• pp.285-285
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• 1998