• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.501-506
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• 2002

In this study, a novel systematic design procedure by Genetic Algorithm of a two stage relief valve is proposed. First of all. a mathematical model describing the dynamics of a balanced piston type relief valve has been derived. Governing equations such as dynamic equations for the main spool and the pilot spool and flow equations for each orifice are established. The mathematical model is verified by comparing the results of simulation with that of experiments. Furthermore, influences of the parameters on the dynamic characteristics of a relief valve have been investigated by simulation of the proposed model. Major design parameters on the valve response are determined, which affect the system response significantly. And then, using the determined parameters, the optimization of the two stage relief valve by Genetic Algorithm, which is a random search algorithm can find the global optimum without converging local optimum, is performed. The optimal design process of a two stage relief valve is presented to determine the major design parameters. Fitness function reflects the changing pressure according to parameters. It is shown that the genetic algorithms satisfactorily optimized the major design parameters of the two stage relief valve.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.1
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• pp.33-38
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• 2006

In this paper, we propose a new architecture of Fuzzy Polynomial Neural Networks(FPNN) by means of genetically optimized Fuzzy Polynomial Neuron(FPN) and discuss its comprehensive design methodology involving mechanisms of genetic optimization, especially Genetic Algorithms(GAs). The conventional FPNN developed so far are based on mechanisms of self-organization and evolutionary optimization. The design of the network exploits the extended Group Method of Data Handling(GMDH) with some essential parameters of the network being provided by the designer and kept fixed throughout the overall development process. This restriction may hamper a possibility of producing an optimal architecture of the model. The proposed FPNN gives rise to a structurally optimized network and comes with a substantial level of flexibility in comparison to the one we encounter in conventional FPNNs. It is shown that the proposed advanced genetic algorithms based Fuzzy Polynomial Neural Networks is more useful and effective than the existing models for nonlinear process. We experimented with Medical Imaging System(MIS) dataset to evaluate the performance of the proposed model.

• Structural Engineering and Mechanics
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• v.17 no.5
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• pp.611-626
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• 2004

On the basis of a structural analysis of radial gate (i.e. Tainter gate), the current paper focuses on weight minimization according to the location of the arms on a radial gate. In spite of its economical significance, there are hardly any previous studies on the optimum design of radial gate. Accordingly, the present study identifies the optimum position of the support point for a radial gate that guarantees the minimum weight satisfying the strength constraint conditions. This study also identifies the optimum position for 2 or 3 radial arms with a convex cylindrical skin plate relative to a given radius of the skin plate curvature, pivot point, water depth, ice pressure, etc. These optimum designs are then compared with previously constructed radial gates. Local genetic and hybrid-type genetic algorithms are used as the optimum tools to reduce the computing time and enhance the accuracy. The results indicate that the weights of the optimized radial gates are appreciably lower than those of previously constructed gates.

• Plant Resources
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• v.8 no.3
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• pp.217-224
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• 2005

We tested the hypothesis that alpine plants have special physiological and biochemical mechanisms in addition to their structural adaptation in order to survive under extreme conditions. The photosynthetic organs of Pinus pumila were used to examine the seasonal changes in sugar concentration, antioxidative enzyme, and lipid peroxidation. The concentrations of sucrose, glucose, fructose and reducing sugar were the highest in the leaves in April. But sugar contents in buds and inner barks did not respond sensitively on temperature change. Meanwhile superoxide dismutase (SOD) activity responded sensitively on the change of temperature and SOD in all tissues maintained high activity in April. Meanwhile anthocyanin content increased rapidly in June but the increase of anthocyanin content was not enough to prevent their tissues from the damage by the exposure of high temperature or other stress. In conclusion, under low temperature condition, P. pumila increased the concentration of soluble sugars and SOD activity in their tissues in order to overcome extreme environmental condition. But in summer, these stress defense system against high temperature might be disturbed slightly. This results in the increase of malondialdehyde (MDA) contents in three tissues by lipid peroxidation.

• Korean Journal of Plant Resources
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• v.20 no.6
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• pp.530-539
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• 2007

Genetic variation and structure of 9 subpopulations of Symplocarpus renifolius Schott ex Tzvelev on Mt. Cheonma, in Korea, were determined via starch-gel electrophoresis. The genetic diversity at 10 loci for 8 isozymes ($P_{99}=66%,\;A=2.26,\;H_o=0.212,\;H_e=0.230$) was found to be considerably higher than that seen in other long-lived perennial plants. On the whole, the genotype frequencies were in accordance with Hardy-Weinberg expectations. Approximately 5%($\theta=0.049$) of the total variability was among subpopulations. The high levels of observed genetic diversity in S. renifolius were attributed to a universal outcrossing system and other specific factors like differences in age classes and widely scattered individuals around the main distribution. Heterozygosity was highest at a mid-range of elevation($450m{\sim}600m$). The lowest heterozygosity at lower elevation was attributed to the possible origin of seeds transported by water from upstream regions during the monsoon season. Spatial structure in a subpopulation evidenced a strong autocorrelation between closer individuals within $3{\sim}4m$ of distance. This was assumed to be attributable to the restricted seed dispersal characteristics of S. renifolius. In accordance with the findings generated in this study, some implications regarding the conservation of S. renifolius at the Mt. Cheonma were also presented.

• Journal of Information Processing Systems
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• v.14 no.3
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• pp.655-665
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• 2018

In efforts to increase its agricultural productivity, the Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development has conducted a variety of genomic studies using high-throughput DNA genotyping and sequencing. The large quantity of data (big data) produced by these biotechnologies require high performance data management system to store, backup, and secure data. Additionally, these genetic studies are computationally demanding, requiring high performance processors and memory for data processing and analysis. Reliable network connectivity with large bandwidth to transfer data is essential as well as database applications and statistical tools that include cleaning, quality control, querying based on specific criteria, and exporting to various formats that are important for generating high yield varieties of crops and improving future agricultural strategies. This manuscript presents a reliable, secure, and scalable information technology infrastructure tailored to Indonesian agriculture genotyping studies.

• Korean Journal of Plant Taxonomy
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• v.52 no.1
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• pp.45-53
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• 2022

Halenia coreana is an endangered, endemic species that is distributed in only a few locations in Korea, such as Mts. Hwaaksan and Daeamsan. It has been recently segregated from H. corniculata, broadly distributed in cold temperate regions that include northern Japan, the Russian Far East, northeastern China, Mongolia, and eastern Europe, where population sizes are usually large. To examine the genetic diversity of H. coreana and evaluate the level of genetic differentiation of the species compared with that of H. corniculata, we surveyed 183 candidate simple sequence repeats (SSR) motif markers for H. coreana and H. corniculata from sequence data of amplified fragments of a specific length in the genome. A total of 17 genomic-SSR markers were selected to examine the levels of genetic diversity and differentiation using 17 samples of H. coreana and 60 samples of three populations of H. corniculata. The results here suggest that the genetic diversity of H. coreana is very low with a high frequency of inbreeding within its population. We found that H. coreana is genetically differentiated from H. corniculata, supporting the recognition of the geographically isolated H. coreana as a distinct species.

• Journal of Genetic Medicine
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• v.20 no.2
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• pp.31-38
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• 2023

Rare diseases, even though defined as fewer than 20,000 in South Korea, with over 8,000 rare Mendelian disorders having been identified, they collectively impact 6-8% of the global population. Many of the rare diseases pose significant challenges to patients, patients' families, and the healthcare system. The diagnostic journey for rare disease patients is often lengthy and arduous, hampered by the genetic diversity and phenotypic complexity of these conditions. With the advent of next-generation sequencing technology and clinical implementation of exome sequencing (ES) and genome sequencing (GS), the diagnostic rate for rare diseases is 25-50% depending on the disease category. It is also allowing more rapid new gene-disease association discovery and equipping us to practice precision medicine by offering tailored medical management plans, early intervention, family planning options. However, a substantial number of patients remain undiagnosed, and it could be due to several factors. Some may not have genetic disorders. Some may have disease-causing variants that are not detectable or interpretable by ES and GS. It's also possible that some patient might have a disease-causing variant in a gene that hasn't yet been linked to a disease. For patients who remain undiagnosed, reanalysis of existing data has shown promises in providing new molecular diagnoses achieved by new gene-disease associations, new variant discovery, and variant reclassification, leading to a 5-10% increase in the diagnostic rate. More advanced approach such as long-read sequencing, transcriptome sequencing and integration of multi-omics data may provide potential values in uncovering elusive genetic causes.

• Journal of Life Science
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• v.25 no.3
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• pp.257-262
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• 2015

The genetic variability of four species of the genus Zoysia collected from South Korea was analyzed using an inter-simple sequence repeat (ISSR) marker system. Polymerase chain reactions (PCR) with eight ISSR primers generated 86 amplicons, 76 (87.1%) of which were polymorphisms. The polymorphism information content (PIC) value of the ISSR marker system was 0.848. The percentage of polymorphic loci (P_p) ranged from 41.2% to 44.7%. Nei’s gene diversity (H) ranged from 0.149 to 0.186, with an average overall value of 0.170. The mean of Shannon’s information index (I) value was 0.250. Total genetic diversity values (H_T) varied between 0.356 (ISSR-1) and 0.418 (ISSR-16), for an average overall polymorphic loci of 0.345. Interlocus variation in within-species genetic diversity (H_S) was low (0.170). On a per-locus basis, the proportion of total genetic variation due to differences among species (G_ST) was 0.601. This indicated that about 60.1% of the total variation was among species. Thus, about 39.9 of genetic variation was within species. The estimate of gene flow, based on G_ST, was very low among species of the genus Zoysia (N_m = 0.332). The phylogenic tree showed three distinct groups: Z. macrostachya and Z. tenuifolia clades and other species were formed the separated clusters. In conclusion, the ISSR assay was useful for detecting genetic variation in the genus Zoysia, and its discriminatory power was comparable to that of other genotyping tools.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.235-241
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• 2017

To preserve genetic materials, cryopreservation of the semen from live animals is the main technique to establish cryo-banking system which could be used for artificial insemination and embryo transfer. However, the population of Korean black goat (KBG) becomes to dwindle in number and is now faced genetic erosion by crossbreeding with non-native breeds in small KBG farms. In this study, simple freezing method was used to preserve frozen semen from KBG using spermatozoa of cauda epididymis (CE) and electro-stimulated semen (ES). The negative effects of seminal plasma on fresh sperm was confirmed using precipitation test of Triladyl egg yolk diluent and sperm viability after thawing was compared between CE and ES spermatozoa. When seminal plasma of fresh ES semen was washed with semen washing media (SWM), the rates of live sperm shown no significant difference between CE and ES spermatozoa before freezing. However, the survival rate of frozen/thawed CE sperm was higher than ES ($74.6{\pm}10.6%$ vs $53.8{\pm}5.2%$) with significant difference (p < 0.05). The results of longevity test on frozen/thawed sperm from CE showed healthier sperm than ES. Therefore, spermatozoa from CE could be used for cryo-banking system in KBG lines. The more studies are needed to increase survival rate of ES semen.