• Journal of Communications and Networks
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• v.12 no.6
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• pp.577-581
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• 2010

We introduce a novel packet retransmission technique which improves the efficiency of automatic retransmission query (ARQ) protocols in the context of satellite broadcast/multicast systems. The proposed coded ARQ technique, similarly to fountain coding, performs transmission of redundant packets, which are made by linear combinations of the packets composing the source block. Differently from fountain codes, the packets for the linear combinations are selected on the basis of the retransmission requests coming from the user terminals. The selection is performed in a way that, at the terminals, the source packets can be recovered iteratively by means of simple back-substitutions. This work aims at providing a simple and efficient alternative to reliable multicast protocols based on erasure correction coding techniques.

• International Journal of Railway
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• v.8 no.1
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• pp.21-29
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• 2015

This study focuses on the performance enhancement of the levitation and guidance control system in urban and medium-to high-speed magnetic levitation trains. A levitation control system, which is currently being tested in Yeongjongdo, is a single controller that is neither designed nor produced on the basis of redundancy. Hence, vehicular stability and reliability should be improved for the situation in which levitation failure occurs because of a breakdown in a controller during vehicle operation. In addition, the control system should be developed to control electromagnetic levitation considering changes in normal force according to changes in the driving force of the propulsion system.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.35-35
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• 2019

Aster spathulifolius Maxim. is belongs to the Asteraceae family which is distributed only in Korea and Japan. It is recognize as a traditionally medicinal plants and economically valuable in ornamental field. However, among the Asteraceae family, the Aster genus, which is lacks in genomic resources and information of molecular function. Therefore, we used high throughput RNA-sequencing transcriptome data of the A. spathulifolius to know molecular level function. DeNovo assembly produced 98,660 unigene with N50 value 1126 bp. Unigenes was performed to analyses the functional annotation against NCBI database like plant database of nucleotide (Nt) and non-redundant protein (Nr), Pfam, Uniprot, KEGG and Transcriptional factor (TF). In addition, Distribution of SSR markers also analyzed for future perfectives. Further, Comparing with other two Asteraceae family species like, Karelinia caspica and Chrysanthemum morifolium to the A. spathulifolius shows the number of gene that regulated in internal and external stress respectively salt-tolerant and heat and drought stress to understand the molecular basis related to the different environments stress.

• Journal of Power Electronics
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• v.19 no.1
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• pp.99-107
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• 2019

This study proposes a new modulation strategy to deal with unbalanced output voltage that is based on three-level neutral-point-clamped cascaded rectifiers. The fundament idea is to reallocate the value of the voltage levels generated by each of the modules on the basis of space vector pulse width modulation. This proposed modulation strategy can reduce the switching frequency while maintaining the mutual-module voltage balance. First, an analysis of unbalanced output voltage is reflected. Then a new modulation strategy is introduced in detail. Internal module capacitor voltages are balanced by the selection of redundant vectors. Moreover, the voltage balance ability is calculated. Finally, the feasibility of this modulation strategy is verified through experimental results.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.30-33
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• 2001

The number of hidden neurons of the feed-forward neural networks is generally decided on the basis of experience. The method usually results in the lack or redundancy of hidden neurons, and causes the shortage of capacity for storing information of learning overmuch. This research proposes a new method for optimizing the number of hidden neurons bases on information entropy, Firstly, an initial neural network with enough hidden neurons should be trained by a set of training samples. Second, the activation values of hidden neurons should be calculated by inputting the training samples that can be identified correctly by the trained neural network. Third, all kinds of partitions should be tried and its information gain should be calculated, and then a decision-tree correctly dividing the whole sample space can be constructed. Finally, the important and related hidden neurons that are included in the tree can be found by searching the whole tree, and other redundant hidden neurons can be deleted. Thus, the number of hidden neurons can be decided. In the case of building a neural network with the best number of hidden units for tea quality evaluation, the proposed method is applied. And the result shows that the method is effective

• Nuclear Engineering and Technology
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• v.26 no.3
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• pp.367-373
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• 1994

It is necessary to adopt a simple signal validation for avoiding the complexity of algorithm and verification in the design process of the instrumentation and control system in nuclear plants. This paper suggests a signal validation method developed on the basis of consistency checking for the multi-channel measurement system without any analytic process model. It includes a simplified algorithm for estimating the fixed bias error of each channel and a weighted averaging method. The weighting factor of each channel is updated according to its calculated bias error. The developed method has been tested to verify its performance through several input scenarios.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.1
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• pp.35-44
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• 2016

Leading national R&D project to design a PWR spent nuclear fuel interim dry storage system that has been under development since mid-2009, which consists of a dual purpose metal cask and concrete storage cask. To ensure the safe operation of dry storage systems in foreign countries, major confinement monitoring techniques currently consist of pressure and temperature measurement. In the case of a dual purpose metal cask, a pressure sensor is installed in the interspace of bolted double lid(primary and secondary lid) in order to measure pressure. A concrete storage cask is a canister based system made of double/redundant welded lid to ensure confinement integrity. For this reason, confinement monitoring method is real time temperature measurement by thermocouple placed in the air flow(air intake and exit) of the concrete structure(over pack and module). The use of various monitoring technologies and operating experiences for the interim dry storage system over the last decades in foreign countries were analyzed. On the basis of the analysis above, development of the confinement monitoring technology that can be used optimally in our system will be available in the near future.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.591-593
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• 1995

Artificial neural network based pattern recognition method is one of the most probable candidate for on-line power system transient stability analysis. Especially, Kohonen layer is an adequate neural network for the purpose. Each node of Kehonen layer competes on the basis of which of them has its clustering center closest to an input vector. This paper discusses Kohonen's LVQ(Learning Victor Quantization) and points out a defection of the algorithm when applied to the transient stability analysis. Only the clustering centers located near the decision boundary of the stability region is needed for the stability criterion and the centers far from the decision boundary are redundant. This paper presents a new algorithm ratted boundary searching algorithm II which assigns only the points that are near the boundary in an input space to nodes or Kohonen layer as their clustering centers. This algorithm is demonstrated with satisfaction using 4-generator 6-bus sample power system.

• BMB Reports
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• v.39 no.4
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• pp.441-447
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• 2006

Abuse of drugs can elicit compulsive drug seeking behaviors upon repeated administration, and ultimately leads to the phenomenon of addiction. We developed a procedure for the standardization of microarray gene expression data of rat brain in drug addiction and stored them in a single integrated database system, focusing on more effective data processing and interpretation. Another characteristic of the present database is that it has a systematic flexibility for statistical analysis and linking with other databases. Basically, we adopt an intelligent SQL querying system, as the foundation of our DB, in order to set up an interactive module which can automatically read the raw gene expression data in the standardized format. We maximize the usability of this DB, helping users study significant gene expression and identify biological function of the genes through integrated up-to-date gene information such as GO annotation and metabolic pathway. For collecting the latest information of selected gene from the database, we also set up the local BLAST search engine and non-redundant sequence database updated by NCBI server on a daily basis. We find that the present database is a useful query interface and data-mining tool, specifically for finding out the genes related to drug addiction. We apply this system to the identification and characterization of methamphetamine-induced genes' behavior in rat brain.

• Journal of Microbiology and Biotechnology
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• v.21 no.8
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• pp.777-790
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• 2011

To elucidate the biodiversity of plant growth-promoting rhizobacteria (PGPR) in Korea, 7,638 bacteria isolated from the rhizosphere of plant species growing in many different regions were screened. A large number of PGPR were identified by testing the ability of each isolate to promote the growth of cucumber seedlings. After redundant rhizobacteria were removed via amplified rDNA restriction analysis, 90 strains were finally selected as PGPR. On the basis of 16S ribosomal RNA sequences, 68 Gram-positive (76%) and 22 Gram-negative (24%) isolates were assigned to 21 genera and 47 species. Of these genera, Bacillus (32 species) made up the largest complement, followed by Paenibacillus (19) and Pseudomonas (11). Phylogenetic analysis showed that most of the Grampositive PGPR fell into two categories: low- and high- G+C (Actinobacteria) strains. The Gram-negative PGPR were distributed in three categories: ${\alpha}$-proteobacteria, ${\beta}$- proteobacteria, and ${\gamma}$-proteobacteria. To our knowledge, this is the largest screening study designed to isolate diverse PGPR. The enlarged understanding of PGPR genetic diversity provided herein will expand the knowledge base regarding beneficial plant-microbe interactions. The outcome of this research may have a practical effect on crop production methodologies.