• Journal of Advanced Navigation Technology
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• v.28 no.1
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• pp.123-128
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• 2024

When mid-span spectral inversion (MSSI), which inverts the propagated wave into phase-conjugated wave in the middle of the entire transmission distance, is combined with dispersion-managed link, it is very effective in compensating for the wavelength division multiplexed (WDM) signal distortion due to chromatic dispersion and nonlinear effects. In this MSSI combined dispersion-managed link, the shape of the dispersion map, channel data rate, channel wavelength and wavelength spacing, etc. affect the compensation and, consequently, determine the transmission distance and capacity of the WDM signal. In this paper, the compensation according to the extinction ratio of the return-to-zero (RZ) pulse that constitutes the WDM signal in the MSSI combined distributed control link was numerically analyzed. As a result of the simulation, it was conformed that the extinction ratio to obtain the best compensation should be determined depending on the shape of the dispersion map and the size of the residual dispersion per span, which determines the specific shape of the dispersion map. These results show a significant difference from the results in a general optical transmission system, where as the extinction ratio increases, the power difference between the '1' and '0' signals increases, thereby improving reception performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.594-597
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• 2012

Optimal link configuration in optical link with concentrated residual dispersion per span (RDPS) in only one fiber span and 0 ps/nm of RDPS in other fiber spans of each half transmission section with respect to optical phase conjugator (OPC) placed at middle of total transmission length is induced in this paper.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1A
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• pp.1-9
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• 2005

We have studied the dispersion properties of a 40 channel x 10 Gbit/s wavelength division multiplexer(WDM) transmission link using standard single mode fiber with all EDFA amplification over 30 x 100 km spans. The dispersion map of the link was investigated by adding fiber sections with positive or negative dispersion at the transmitter, within each amplifier span, and at the receiver. Optimum combinations of these dispersive fiber lengths were attained to significantly enhance the overall transmission performance.

• Industrial Engineering and Management Systems
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• v.12 no.2
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• pp.112-117
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• 2013

The $\overline{x}$ control chart for the process mean and either the R or s control chart for the process dispersion have been used together to monitor the manufacturing processes. However, it has been pointed out that this procedure is flawed by a fault that makes it difficult to capture the behavior of process condition visually by considering the relationship between the shift in the process mean and the change in the process dispersion because the respective characteristics are monitored by an individual control chart in parallel. Then, the ($\overline{x}$, s) control chart has been proposed to enable the process managers to monitor the changes in the process mean, process dispersion, or both. On the one hand, identifying which process parameters are responsible for out-of-control condition of process is one of the important issues in the process management. It is especially important in the ($\overline{x}$, s) control chart where some parameters are monitored at a single plane. The previous literature has proposed the multiple decision method based on the statistical hypothesis tests to identify the parameters responsible for out-of-control condition. In this paper, we propose how to identify parameters responsible for out-of-control condition using the information criterion. Then, the effectiveness of proposed method is shown through some numerical experiments.

• Journal of Advanced Navigation Technology
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• v.24 no.5
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• pp.408-414
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• 2020

The method of overcoming the limitation of optical phase conjugator applied into optical long-haul link for transmitting high capacity wavelength division multiplexed (WDM) channels was investigated. The configuration of optical link was based on dispersion-managed link, in which dispersion compensating fiber inserted into each fiber span with single mode fiber, and optical phase conjugator was added into suitable location of link. The maximum number of fiber spans as a function of the launch power of WDM channels in optical link with optical phase conjugator placed at the proposed location was induced and compared for analyzing the compensation performance of the distorted WDM channels. It was confirmed that the more optical phase conjugator depart from the midway of total transmission length, the less the distorted WDM channels was compensated, however, it was also confirmed that the degradation of compensation can be overcome by the suitable value of residual dispersion per span and by the reasonable choice of fiber span controlling total dispersion accumulated in overall transmission link.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2293-2302
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• 2012

New optical transmission links technique for compensating of the distorted wavelength division multiplexed (WDM) signals due to group velocity dispersion (GVD) and self phase modulation (SPM) in single mode fiber (SMF) are proposed. The proposed optical links have optical phase conjugator (OPC) placed at nearby WDM transmitter or receiver and repeater spans with artificial distribution of SMF length and residual dispersion per span (RDPS). It is confirmed that optimal link configuration expanding effective launching power range and effective net residual dispersion (NRD) by improving system performance is that having OPC closely placed at WDM receiver and the gradually descended distribution of SMF length and RDPS of each repeater spans, related with the gradually increased optical link length. And, it is also confirmed that NRD is controlled by postcompensation in optimal optical link with OPC closely placed at WDM receiver.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.369-374
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• 1999

The problem of bandwidth allocation and routing in VP based ATM networks was studied. A priori reservation of resources for VP's reduces the statistical multiplexing gain, resulting in increased Call Blocking Probability (CBP). The focus of this study is on how to reduce CBP by the efficient bandwidth allocation and routing algorithms. Equivalent capacity concept was used to calculate the required bandwidth by the call. and the effect of traffic dispersion was explored to achieve more statistical gain. A cost-effective traffic dispersion routing algorithm, CED, was designed. The algorithm finds the optimal number of dispersion paths for a call, where the gain balances the dispersion cost. Simulation study showed that CED could significantly reduce the CBP.

• The Journal of Fisheries Business Administration
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• v.46 no.2
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• pp.43-57
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• 2015

The study aims to identify the current status of aquaculture information in Korea and suggests policy directions for its integrated management. Firstly, the study focuses on the identification of the current status of aquaculture information by reviewing how aquaculture information is managed. Secondly, this study identifies problems such as lacks in necessary aquaculture information, inefficiency caused by dispersion and overlapping of information, absence of integrated management system and insufficient sharing of information. After identifying the current status of aquaculture information and its problems, the study suggests three basic directions to systematically integrate and manage the information such as establishment of infrastructure for promoting the integrated management of aquaculture information, generation and systematic management of useful aquaculture information and enhancement of user convenience. Finally, the study suggests detailed strategies such as establishment of a foundation to facilitate integrated management of aquaculture information, organization of organic network, sharing of more information, creation of necessary information through demand survey, creation of systematic management system, provision of a customized total service, and increase in education and PR activities on information use.

• Journal of Advanced Navigation Technology
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• v.23 no.3
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• pp.251-257
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• 2019

The configuration of ultra-long optical transmission link with dispersion management and optical phase conjugation is proposed. The whole transmission link consist of 80 km (single mode fiber span) ${\times}$ 56 fiber spans. The artificial distribution of single mode fibers' lengths and residual dispersions in fiber spans, which are gradually increased/decreased as the span number is increased, is adopted to compensate for the distorted wavelength division multiplexed channels. Since the compensation effect through the artificial distribution in the previous researches is expected to decrease as the number of fiber spans are increased, three-time repetition of the artificial distribution patterns at intervals of 9 fiber spans applied into the link with dispersion management and optical phase conjugation is proposed. From the simulation results, it is confirmed that the compensation in the link configured by the special distribution pattern among 4 proposed patterns is slightly improved than the link configured by the conventional method, which is designed by the repeat-less distribution pattern.

• Journal of Korean Society of Archives and Records Management
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• v.8 no.1
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• pp.65-96
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• 2008

The Retained documents disposal project, promoted in 1968 and 1975, was executed as part of administrative plans for prompt movement of the government in case of national emergency. It was main contents that archival documents were re-appraised and reduced the least, and then moved rearward. The Retained documents disposal project denied The Records Management System of Korean Government that had been founded in 1964, promoted reduction of documents physically for convenience to dispersion of the government. Korean Government had completed these projects and then reorganized records management system to reduce creation of archival documents systematically in 1979.