• The Journal of the Korea institute of electronic communication sciences
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• 제5권4호
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• pp.450-456
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• 2010

In the high-speed packet service, next generation mobile communication system has emerged as a major feature. If the fire of these high-speed kit services and non-continuous transmission of data due to the symmetrical nature of daeyiteo traffic for D-CDMA system has been actively studied. Small amounts of data moving in the uplink, but the real-time video downlink transmission, such as downloading large files to move data and services to those with asymmetric traffic characteristics, a system that can efficiently handle the data requirements be. Of 3GPP TDD(Time Division Duplex) scheme based on CDMA and TDMA in a way by introducing the concept through the proper allocation of time slots that can handle asymmetric traffic efficiently, has an advantage. TD-CDMA system by considering the characteristics of the frame configuration of transmission methods, such as physical channel structure and channel coding has been investigated. In addition, the HARQ scheme TD-CDMA system performance is analyzed by comparing them.

• Journal of Broadcast Engineering
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• 제12권2호
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• pp.120-127
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• 2007

In this paper, we describe a new 1/4 rate robust modulation techniques for Enhanced-x VSB system which is fully backward compatible with ATSC 8-VSB standard. 1/4 rate mode Enhanced-xVSB system provides broadcasters with a wide choice of trade-offs of data rate vs amount of robustness of enhanced data for pedestrian/mobile services. Lab test results of proposed Enhanced-x VSB 1/4 rate mode robust stream are a significantly improved multipath as well as AWGN reception performance for Enhanced-x VSB receiver. We suggest an Enhanced-x VSB terrestrial broadcasting system for ATSC HDTV and pedestrian/portable TV simultaneous broadcasting service providing.

• Journal of the Korean Society of Costume
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• 제56권4호
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• pp.33-47
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• 2006

In 21 century, the ubiquitous environment is advanced fast through the so-called digital convergence. This research experts what is the next generation of traditional fashion product purchase behaviors. The purpose of this study is to analyze the fashion product purchase decision making in the development stages of ubiquitous environment. The quantitative Investigation was executed for 487 collegians and the data were analyzed with Frequency, percentage, ANOVA, Duncan test and multiple regression by using SPSS win version 10 package. The results of this research were as followed: First, in the 1st stages of ubiquitous developmental environment, using internet pc or mobile phone was analyze the difference between fashion shopping orientation group and purchase restricted factor Second, as a result of the factor analysis of the ubiquitous 2nd stages, four lower dimensions were made: giving information; wearable effect, buying facility; interest from purchase. as a result of ANOVA, there were any differences between fashion shopping orientation group and ubiquitous 2nd stages. Third, in the 3rd stages of ubiquitous developmental environment, there are differences between fashion shopping orientation group and ubiquitous 3rd stages. And the result from regression analysis of the ubiquitous 2nd stages and 3rd stages showed that buying facility factor in increasing need recognition, wearable effect factor in fashion information acquisition, giving information factor in have a intention to buy in ubiquitous #3 rendition are most influential.

• Journal of Internet Computing and Services
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• 제12권3호
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• pp.101-110
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• 2011

WMN is highlighted as a next generation network technology due to relatively reasonable cost to be built, compared with the pre-existing wireless network. It also enables same kind of network or even other kind of network to be integrated. Some WMN researches support mobility using router protocol such as AODV and DSR because WMN has the similar features with Ad-hoc network in terms of operation. However, WMN has got different operations with additional functions of multi-interface and internet connect, it can't be a good method to manage efficient mobility any more. This study suggests method to apply MAP function of HMIPv6 to WMN as a way to manage WMN mobility. Through simulation, operation was verified and function was appreciated. Through the results of evaluation, the suggest mobility management had shorter handover delay and packet loss reduced, which improved whole network throughput rate, compared with mobility management using AODV.

• Journal of Broadcast Engineering
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• 제15권6호
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• pp.749-756
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• 2010

The signal space diversity is one of the promising transmission techniques in next generation mobile TV service. However, DVB-T2 does not consider the multiple antennas (MIMO) so that the cyclic Q-delay method, a component interleaver in DVB-T2, causes a critical issue in detecting symbols at the receiver side by increasing the inter-symbol dependency. To solve this problem, the component-swapping technique is proposed, which limits the inter-symbol dependency in order to reduce detection complexity. In this paper, the achievable gain of a component-swapping technique combined with 16K LDPC code defined in DVB-T2 is evaluated by computer simulations. From the results, the gain is confirmed in terms of BER and receive complexity compared to legacy component interleaver methods.

• Journal of Advanced Navigation Technology
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• 제6권1호
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• pp.69-76
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• 2002

With the growth of data communication service by mobile devices, WAP is proposed to efficiently access the Internet contents by user request through wireless condition that has a high error rate and mobility. But, because a transmission speed of WAP is limited, it takes many times to transmit and to receive the data. This paper has studied the WAP packet transmission time using WTP-SAR algorithm. As a method that is to improve transfer capability of WAP, using SAR function in WTP, total message down from upper layer has been fragmented and packet is transmitted through RLP frame time slot. Then, we have analyzed the transmission time of WAP packet with variable RLP layer size on the wireless CDMA network for next generation systems. From the results, we could obtain the WAP packet transmission time and optimal WTP packet size.

• Journal of Satellite, Information and Communications
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• 제10권2호
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• pp.90-94
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• 2015

We stuidied liauid crystal alignment treatment using solution process for making thin oxide layer in liquid crystal display. It is the one of very effient and popular process in making thin oxide layer in electronical industrial fields. Particularly, this process has highly potential value in liquid crystal display industrial fields because it cause automatically induced alignment process without tranditional alignment process in liquid crystal alignment process. We made several different kinds of mol density solutions using strontium oxide solution. And those solutions were treated for solidification layers using annealing process for 2 hours. And we stuided pretilt angle properties of these alignment layers of strontium oxide for clarifying the relationship of liquid crystal molecules and thin strontium oxide layer. And we also tested the existence of strontium oxide thin layer on substrate using XPS measurement. We expected the hig gain of electro-optical properties in liquid crystal display using strontium oxide thin layer because it has high K property material than the other metal-based oxide layers. In this results, we measured 1.447 to 1.613 thresholds volts as 0.1 mol to 0.4 mol density in 0.1 mol density steps. This is significant better characteristics than conventional liquid crystal display as higher than 1.85 thresholds volts. And it make possible to making next-generation liquid crystal display which present low-power consumption and wide gray scale in liquid crystal display.

• Journal of KIISE:Databases
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• 제37권2호
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• pp.121-126
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• 2010

This paper proposes an efficient index scheduling technique for kNN query processing in multiple wireless broadcast channel environment. Previous works have to wait for the next cycle if the required child nodes of the same parent node are allocated in the same time slot on multiple channel. Our proposed method computes the access frequencies of each node of R tree at the server before the generation of the R-tree index broadcast schedule. If they have high frequencies, we allocate them serially on the single channel. If they have low frequencies, we allocate them in parallel on the multiple channels. As a result, we can reduce the index node access conflicts and the long broadcast cycle. The performance evaluation shows that our scheme gives the better performance than the existing schemes.

• Journal of the Korea Society for Simulation
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• 제15권3호
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• pp.87-91
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• 2006

With the growth of the internet, the number of wireless internet users has increased continuously up to date. However, mobile communications could not support high speed transmission rate with cheap communication fee and wireless LAN has problems in providing terminal mobility and wide area connectivity, respectively. So the WMAN standard has been newly designed to make up for these limits. The initial 802.16 specification effectively offers a solution for providing fixed users with high speed wireless communication but it does not offer terminal mobility. So the 802.16d and 802.16e have been developed as the next generation solution that can support various PHY layer (SC, SCa, OFDM, OFDMA) and offer the terminal mobility. In this paper, we propose an effective uplink scheduling algorithm for VoIP with using UGS, and we show that our proposed algorithm is superior in view of average delay and management of uplink bandwidth to conventional rtPS algorithm and the scheme in reference, with using NS-2 network simulator.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제17권6호
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• pp.113-119
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• 2017

The Rich Communication Service(RCS) is a next generation mobile messaging service. Since it has been developed and managed by a wireless service provider, 3rd party application developers cannot utilize the RCS features in their apps. A few studies have been proposed to solve this problem, even though they were not viable level of deployment. This paper presents a Web-based Rich Communication Service Software Framework(WebRSF) to help the 3rd party application developers adopt RCS features easily. WebRSF converts complicated RCS protocols to simple web-based protocols for providing the RCS 1-to-1 chat service to the 3rd parties. Communication protocols between WebRSF and its clients are defined in this paper. Also, a network configuration diagram and a message flow diagram are defined. Finally, performance evaluation between the WebRSF client and the RCS client are performed to simulate the load on clients' devices. It shows that the WebRSF client has 17% less loads than the RCS client while initiating sessions, and has 25% more loads after initiating sessions.