• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12A
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• pp.925-932
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• 2009

Precise temperature monitoring is the major preconditioning to supervise quality losses within the transport chain for fresh products. ISO/IEC18000-6REV1 defines new protocols supporting BAP(Battery Assisted Passive) RFID tag which is completely compatible with EPCglobal Class1 Generation2 specification. In this paper, we designed a modem supporting BAP RFID tag with FPGA(Field Programmable Gate Array) and implemented sensor data processing function defined in ISO/IEC18000-6REV1. The transmit block of the modem supports pulse shaping filter and the output signal of the implemented RFID reader is satisfied with the spectrum mask defined in the standard. The receive block of the modem uses Gardner TED to synchronize timing of symbol. In this paper, we designed a modem supporting ISO/IEC18000-6REV1 standard and developed a RFID reader sndard. The developed RFID reader sndard can recognize sensor tag and passive tag in the wireless environment and supports real-time processing of the sensor data in the embedded linux platform.

• Journal of Digital Convergence
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• v.14 no.10
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• pp.261-269
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• 2016

This paper aims to propose a novel technology of network convergence to provide ultra high speed internet services over CATV networks, by which a CMC(cable modem concentrator) and CM(cable modem) of 1Gbps level are designed. This technology not only lowers the production cost in comparison to the existing bonding technology with DOCSIS specification but also enables the adjustment of data speed based on the channel bandwidth. According to the experiments, when convolutional code rate with 128QAM is changed to 1/2, 2/3, 3/4 and 7/8, the data recorded the maximum transmission speed of up to 299 Mbps at the zero error rate. As the convolutional code rates with 256QAM is increased, it showed 334Mbps at the error rate of $10^{-5}$. Based on the findings of this paper, if we secure the channel bandwidth of 200MHz and adjust the modulation order of QAM and the convolution code rate depending on the channel status, we can get the transmission speed of more than 1Gbps, which is much more competitive in its function and price than the existing technology based on DOCSIS.

• Journal of Advanced Navigation Technology
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• v.18 no.5
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• pp.490-493
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• 2014

To protect the students from food poisoning, in this paper, it is proposed that the Smart HACCP system which based with WCDMA-LTE to monitoring the temperature and humidity of a freezer, a heating cabinet and kitchen instruments at the elementary, junior and high school. After gathering the data, It is compared with a standard food poisoning index to provide more safe food reserves from the server. Then the server send a index to the terminal which is installed in a kitchen at any school to show the current environment. It is need an WCDMA-LTE terminal to realize smart HACCP system that is proposed from this paper. So, the proposed WCDMA-LTE terminal is designed with using a LTE modem included a 424 MHz wireless modem and a bluetooth 4.0 modem to communicate with other terminals. It can be use the monitoring system of a plastic greenhouse or remotely environment control system.

• Korean Journal of Human Ecology
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• v.15 no.4
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• pp.585-595
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• 2006

The purpose of this study is to classify the fashion images on sportive style, to find out the difference between the image of sportive style which consumers prefer and the image of sportive style which they want to show and, finally, to analyze their purchase behavior. This research is done with survey method. The subjects of the survey are 835 females in their twenties or their thirties in Pusan area. The data are analyzed with factor analysis, Cronbach's alpha, $X^2$-test, and frequency analysis. The results of this study are as follows: first, sportive style is classified into Sexy, Romantic, Active and Modem image. Second, the results of analysis on consumers' preferring image and their wanting-to-show image to the above-mentioned image classification are as follows: firstly, the subjects' most preferring image and the image which they most want to show is Modem in1age. The second is Sexy image. But the subjects preferred having Modem image. Secondly, consumers' Individuality and apparel's Function are the important reasons to choose the sportive style. Thirdly, Modem image is the most preferred in the images of street wear. Sexy image and Active image are the preferred in the images of sports wear. Third, It is a vivid tone and a dark tone that is the color tone of sportive wear which consumers prefer. They prefer a logo- patterned sports wear, too. The consumers obtain most information on sports wear from sports wear stores. Silhouette is the most decisive design element in consumers' purchasing. The sports wear brands which the subjects prefer are Adidas and Nike.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.4
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• pp.846-851
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• 2009

This study is to look into the spatial cognition of modern space in the nineteenth century and it is on the purpose of understanding the character of the modem architectural space and of showing the modern architectural space connected with modem society and its everyday life. Especially, fur understanding the spatial cognition of modern space, the Landscape Gardens will be analyzed. The reason for analyzing is that the Landscape Gardens are important theme in the nineteenth century and have great influence on whole European architecture and city. The Landscape Garden produce several modern spaces, that are (1) space of dynamic vision, (2) space of panorama, (3) space of spectacle. These spaces make modem cognition of space and pervade the space of everyday life in the nineteenth century. As a result, the modern spaces and their cognitions are in deep relation to modern society and its everyday life, and unique characters of that spaces are origin of the modem architecture and its space.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.902-908
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• 2009

TETRA is the standard of Digital Trunked Radio System developed by the ETSI (European Telecommunications Standards Institute). It is currently adopted as Electric Power IT Wireless Backbone Network in Korea, and a national enterprise is going on for versatile utilization of TETRA. To use TETRA wireless network, TETRA modem is very necessary such that performance measurements are very crucial for each TETRA modem by various manufacturers. In this paper, PED (Protocol Evaluation Data) is suggested for PD performance measurement in D-TRS wireless network environment. The performance measurements for different data lengths and transmission intervals are done using TG (Traffic Generator) on Test Bed. The data size is increased by 10 bytes from 10-byte to 400-byte, and it is measured 1,000 times for each transmission interval of 0.5, 1.0, and 1.5 seconds. Based on the transmission time measured, average transmission speed and MER (Message Error Rate) are derived for TETRA Modem performance measurement. Two TMR880i's of EADS are used for TETRA modem, and SwMI (Switching and Management Infrastructure) of EADS is used for switching system in this paper.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.8
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• pp.9-16
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• 2007

Currently, the measurement of RF parameters for a base station in operation is typically limited to easily measured forward path items. In this paper, the forward monitoring ports of base stations are used to measure the reverse RF performance. The system has been implemented and effectiveness has been proven on an operating base station. The receiver sensitivity is measured using an internal CDMA modem which is used to monitor the output power based on closed loop power control when the modem is connected to the base station via a voice call. In order to improve accuracy, in addition to the modem Tx adjust(TxAdj) parameter, the detector's actual measurement is used. For accurate receiver sensitivity, the measurement should be made when there is no traffic which is not possible on an operating base station. Therefore, pilot channel chip energy to received signal power spectral density ratio$(E_c/I_o)$ compensation method is used to offset the receiver sensitivity degradation with voice traffic increase.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.2
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• pp.24-30
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• 2009

In this paper, the FPGA modem platform complying with 3GPP Release 7 eHSPA specifications and its regularized verification flow are proposed. The FFGA platform consists of modem board supporting physical layer requirements, MCU and DSP core embedded control board to drive the modem board, and peripheral boards for RF interfacing and various equipment interfaces. On the other hand, the proposed verification flow has been regularized into three categories according to the correlation degrees of hardware-software inter-operation, such as simple function test, scenario test call processing and system-level performance test. When it comes to real implementations, the emulation verification strategy for low power mobile SoC is also introduced.

• Journal of Advanced Navigation Technology
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• v.16 no.2
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• pp.234-239
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• 2012

Next generation mobile communication systems have been studied and applied to support various services. In next generation mobile communication systems, the most interested research is the integration of various communication systems and the offer of various services by using high-speed data transmission. The integration of communication systems has been researched by using multi standard modem, while the high-speed data transmission for the offer of various services has been applied by using OFDM. This paper has proposed the method to reduce PAPR by using multi standard modem. with EVM, this paper has also suggested the method to compensate in-band distortion while reducing PAPR. By using the proposed methods, this paper has analyzed and simulated the decrease efficiency of PAPR, the performance of CCDF, and the performance of BER in next generation mobile communication systems. The simulation results improved the performance of next generation mobile communication system can be seen that.

• Journal of Advanced Navigation Technology
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• v.14 no.2
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• pp.213-219
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• 2010

Recently, a multi-core system is studied for single terminal's operations on various service networks for mobile systems. Therefore, it is expected that mobile systems capable of supporting WCDMA, MC-CDMA, CDMA and WiBro would be developed. Mobile systems for supporting various service networks is able to be implemented on a single chipset via SoC(System one Chip) technology, thus a noble modem design proper for SoC technology is necessary. For high speed data transmission of 4G mobile communication services, OFDM scheme has to be applied. But, an OFDM signal consists of a number of independently modulated subcarriers, and superposition of these subcarriers cause a problem that can give a large PAPR. In this paper, a noble modem design for 4G mobile communication services and PAPR reduction method for solving the PAPR problem are proposed.