• Title/Summary/Keyword: Channel Environment

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Concatenated Zigzag(CZZ) Code for Improving Error Performance of Uplink Data in Marine Environment (해상 환경에서의 업링크 데이터의 오류성능 개선을 위한 CZZ 부호화)

  • Yun, Jung-Kug
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.4
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    • pp.648-654
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    • 2011
  • We can model marine uplink channel environment as time-correlated rician fading channel that has direct path and time varying reflected path. In this channel, error performance of uncoded system can be seriously degraded by multipath inteference. In this paper, we propose Concatenated Zigzag(CZZ) coded binary FSK signaling with noncoherent detection to improve error performance of uplink data in marine environment. CZZ code is a kind of channel coding scheme that is fast decodable as well as fast encodable. We have confirmed error performance of uplink data in marine environment can be improved dramatically through applying CZZ code.

A Study on Unsteady Flow Characteristics of Triangular Grooved Channel (삼각형상 그루브 채널의 비정상 유동특성에 관한 연구)

  • 조대환
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.8 no.1
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    • pp.101-108
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    • 2002
  • This experimental study was performed to investigate internal flow and unsteady flow characteristics using a model for actual shape of a Plate heat exchanger and visualization of flow through the particle image velocimetry. Seven Reynolds numbers were selected by calculation with the height of grooved channel and sectional mean velocity of inlet flow in the experiment, and instantaneous velocity distributions and flow characteristics were experimently investigated. The triangular grooved channel had a compound flow consisting of the flow in lower channel and the groove flow receiving shear stress by the channel flow in the experiment. The sheared mixing layer, in the boundary between the triangular groove and the channel. affected main flow to raise turbulent in the channel.

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Assessing the Effects of Multi-Channel Service Quality on Customer Satisfaction and Loyalty in Retail Banking (은행서비스의 다채널 별 서비스 품질 평가가 고객 만족 및 충성도에 미치는 영향)

  • Kim, Jiyoung
    • Journal of the Korean Operations Research and Management Science Society
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    • v.41 no.1
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    • pp.71-85
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    • 2016
  • Service channel environments have changed dramatically with the advent of new, online digital channels. This article studies the effects of perceived multi-channel service quality on customer satisfaction and loyalty in the banking industry and the moderating role of age, which is a characteristic of customers. The objective is to identify the quality factors that affect the overall satisfaction and loyalty of a multi-channel customer. A quantitative study was conducted on 900 customers, with the main targets being users of the nine primary Korean retail banks. Results show that perceived service quality of the physical environment, human service, Internet banking, mobile banking, and ATM has a positive influence on overall satisfaction and loyalty. Age moderates the relationship among physical environment quality, human service, and customer loyalty.

Trend Analysis of the COD and Nutrients Concentrations in the Yongwon Channel, Chinhae (진해 용원수로의 COD 및 영양염류 농도 추세분석)

  • Cho, Hong-Yeon;Chae, Jang-Won;Park, Joung-Guy;Koo, Myung-Seo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.4
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    • pp.421-428
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    • 2008
  • Youngwon channel located in Chinhae city and formed by the Busan New Port Construction Project has been concerned about the water quality degradation problems because of the flow and pollutants stagnation due to its long-narrow shape. In this study, the water quality(hereafter WQ) variation is analysed by using the monthly WQ data measured in Yongwon channel from 2003 to 2007. The analysis shows that the TN and TP concentration in the inside Yongwon channel is definitely worse than the TN and TP concentration in the entrance of the Yongwon channel based on the 95% confidence level. The COD, TN, and TP concentrations in the Yongwon channel are 1.34, 2.08, and 1.80 times larger than that in the entrance of the Yongwon channel, respectively. It has been found that only the TP concentration in SW-26 station has an increasing trend based on the Mann-Kendall test with respect to 95% confidence level. The other stations and the other WQ constituent changes do not have the any significant trends.

A Study on Ship-handling Difficulty in Bend Channels (조선환경스트레스 모델을 이용한 편도항로 만곡부에서의 선박조종 난이도 평가에 관한 연구)

  • 나상각;문채식;윤명오;금종수;노창균
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.9 no.1
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    • pp.57-63
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    • 2003
  • Marine traffic system is composed of ship, ship's operators and traffic environment The navigation channel is a part of traffic environment and the design of channel is a crucial factor for safe navigation This paper aims to evaluate ship-handling difficulty in straight and bend channels with an Environmental Stress model(ES-model). The ES-model is used to evaluate ship handling difficulty quantitatively on the basis of the ship operator's subjective judgement for safety in navigation The calculation of ES value was made on the basis of three factors such as channel width, ship's length and speed in straight and channels for safe navigation. The interrelation between factors was analyzed and reasonable design standards of channel width, ship's length and speed were proposed for safe navigation of ship in bend channel.

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Evaluation of Interference Alignment for MIMO-IC based on IEEE 802.11n (IEEE 802.11n 기반 MIMO-IC의 간섭정렬 성능평가)

  • Bae, Insan;Yun, Heesuk;Kim, Jaemoung
    • Journal of Satellite, Information and Communications
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    • v.8 no.4
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    • pp.47-52
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    • 2013
  • In this paper, The existing interference alignment algorithms were analyzed in Rayleigh fading channel environment. The interference alignment techniques are divided to two parts. First thing is Iterative-method, another is Linear-method. Iterative method needs local channel info, but it has the constraint of iteration. On the other hand Linear-method must have global channel info, but has free of iteration and better performance. This paper evaluates the performance of interference alignment algorithms in Rayleigh fading channel of outdoor environment and WLAN channel based on IEEE 802.11n of indoor environment.

A Simulation Study on the Improvement of the Entrance Channel of Masan Harbour (마산항 출입 항로의 개선 방안에 관한 시뮬레이션 연구)

  • 김환수
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.3 no.1
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    • pp.15-31
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    • 1997
  • This work aims at examining the navigational safety of the entrance channels of Masan harbour and suggesting the way to improve ships' navigational safety through the channels. It has been found, from the on-scene investigation of the navigational safety at Masan, that the depth of the Budo-Sudo channel is not deep enough to cater for the largest vessel visiting the harbour, and that the No.2 navigational channel is not wide enough for the vessel. An additional new waterway, therefore, has been recommended to be established in the south of the Budo-Sudo channel so that the deep draft vessel can detour. The No.2 navigational channel has been recommended to be widen. The width of the channel was suggested to be 280 meters. A waterway design simulation methodology has been applied to examine the safety of the newly suggested channels. New channels have been proved to be safe from the experiment.

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Performance Evaluation of JADE-MUSIC Estimation for Indoor Environment

  • Satayarak, Peangduen;Rawiwan, Panarat;Chamchoy, Monchai;Supanakoon, Pichaya;Tangtisanon, Prakit
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1654-1659
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    • 2003
  • In this paper, the performance evaluation of the JADE-MUSIC estimation based on the indoor channel is presented. By means of the JADE-MUSIC algorithm, DOA and time delay can be obtained simultaneously. In the JADE-MUSIC method, the channel impulse response is first estimated from the received samples and then this impulse response is employed to estimate DOAs and time delays of multipath waves. Moreover, according to the JADE-MUSIC characteristics, it can work in cases when the number of impinging waves is more than the number of antenna elements, unlike the traditional parametric subspace-based method, such a case is not true. Therefore, we employ the JADE-MUSIC algorithm applying for the real indoor environment where is rich of the multipath propagation waves and can imply that the number of waves is very possibly higher than that of the array element. The experiment is carried out in our laboratory considered to be the real indoor environment. The performance of the JADE-MUSIC algorithm is evaluated in terms of the comparison between the simulation and experiment results by using the simulated channel model and the real indoor channel model, respectively. It is clear that the joint angle and delay estimation using the simulated channel model are in good agreement with the estimation using the real indoor channel model. Therefore, we can say that the JADE-MUSIC algorithm accomplishes the high performance to jointly estimate the angle and delay of the arriving signal for the indoor environment.

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An Analysis on the Omni-Channel Strategy of Distribution Enterprise in Domestic and International (국내·외 유통업체의 옴니채널 전략 활용현황 분석)

  • Oh, Jung-Ah
    • Korean Institute of Interior Design Journal
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    • v.25 no.5
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    • pp.111-120
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    • 2016
  • Unlike the past, brick-and-mortar is no longer on the priority list for the shopping activity. Instead, it is replaced by various non-store shopping alternatives, such as Internet, TV, catalog, mobile, etc. As consumers engage digitally, they made fewer trips to stores. Especially, as mobile shopping made the price comparison possible while shopping in the store, new shopping trend of 'showrooming' came to the fore as the serious issue. In order to cope with the this crisis, many brick-and-mortar retailers utilize omni-channel strategy for their countermeasure. This research paper is to suggest the omni-channel strategy that is applicable for the brick-and-mortar retailers. The results are as follows. First, in order to set up the connected-channel shopping environment, consumers have to be exposed to the environment that can deliver the continuous brand experience under the same price policy, brand and store management, etc, as integrating the various purchasing channels into one. Especially, in-store environment needs to change for the place where consumer experience is stressed for the most as using virtual reality devices with augmented reality technology. Also, the online digital kiosk, and tablet that consumer can order the products through the online channel while shopping in-store Second, the barrier-free in-store environment should be offered in order to increase the consumer convenience. This change will allow consumer communicate with the store environment more effectively. Lastly, brick-and-mortar should extend the physical territory as utilizing the offline's advantage and disadvantage through setting up the digital interactive wall or pop-up store for increasing the opportunity of customer interaction with the store. Moreover, visiting service for the elderly, housewife with the baby, or disabled person will be one of the effective substitute.

A Channel Borrowing Scheme using Genetic Algorithm in Cellular Mobile Computing Environment (셀룰라 이동 컴퓨팅 환경에서 유전 알고리즘을 이용한 채널차용 기법)

  • Lee, Seong-Hoon;Lee, Dong-Woo;Lee, Sang-Gu
    • Journal of KIISE:Information Networking
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    • v.29 no.2
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    • pp.165-173
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    • 2002
  • In the static channel assignment scheme for cellular mobile computing environment, each cell has a fixed number of channels and supports a service for a user′s request entering to the cell. This scheme has an advantage of simplicity. However, this scheme has a disadvantage that can′t control far hot cell problem. Therefore, to solve this problem, the "channel borrowing" concept is needed. In this paper, we propose a load balancing(channel borrowing, channel reassignment) approach using genetic algorithm. The purposes of using genetic algorithm in this paper are ${\circled1}$ to find early a cell including an available channel and ${\circled2}$ to decrease a number of probings and ${\circled3}$ to migrate to the cell after searching an available channel near upon optimality. To represent effectiveness of the proposed algorithm, we simulated various experiments.