• Journal of Ocean Engineering and Technology
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• v.32 no.5
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• pp.297-309
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• 2018

After an accident involving mooring link failures in an offloading buoy, verification of the fatigue safety in terms of the out-of-plane bending (OPB) and in-plane bending (IPB) moments has become a key engineering item in the design of various floating offshore units. The mooring links for an 8 MW floating offshore wind turbine were selected for this study. To identify the OPB stiffness (OPB moment versus interlink angle), a numerical simulation model, called the 3-link model, is usually composed of three successive chain links closest to the fairlead or chain hawse. This paper introduces two numerical simulation techniques for the 3-link analyses. The conventional and advanced approaches are both based on the prescribed rotation approach (PRA) and direct tension approach (DTA). Comparisons of the nominal stress distributions, OPB stiffnesses, hotspot stress curves, and stress concentration curves are presented. The multiple link analyses used to identify the tension angle versus interlink angle require the OPB stiffness data from the 3-link analyses. A convergence study was conducted to determine the minimum number of links for a multi-link analysis. It was proven that 10 links were sufficient for the multi-link analysis. The tension angle versus interlink angle relations are presented based on multi-link analyses with 10 links. It was found that the subsequent results varied significantly according to the 3-link analysis techniques.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.11-14
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• 2003

NF733xin, the near allele line was obtained by means of crossing and backcrossing the silkworm race T6, which contained fluoride resistance major gene, to race 733xin, which was highly susceptible to fluoride toxicity. Two hundred RAPD random primers were used in the RAPD analysis of these 3 strains. Two molecular markers, OPB-08850 and OPB-10917, were obtained. OPB-10917 was used to detect the backcross generations. It was found that all the fluoride resistant individuals in each backcross generation had the same special band. These results proved that this marker was reliable.

• Journal of Life Science
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• v.32 no.8
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• pp.595-600
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• 2022

Water dropworts, Oenanthe javanica and O. javanica var. japonica are called "minari" in Korea and are eaten as a vegetable. Cicuta virosa is common European water hemlock and has toxic properties, such as cicutoxin. Molecular variations of water dropwort species in Korea were investigated using random amplified polymorphic DNA (RAPD). The six populations were studied with 10 primers (Operon, OPB) for RAPD analysis. The 72 DNA fragments (bands) were found among six populations. Among these 72 bands, 61 (84.7%) bands were polymorphic. The typical populations of Cicuta virosa in Korea were small, isolated, and patchily distributed for natural populations and they maintained a high level of genetic diversity. However, when cultivated populations of O. javanica var. japonica were large and widely grown in rice paddies as vegetables, they maintained a lower genetic diversity than those of C. virosa and wild populations of O. javanica. Although the diversity indices of wild populations were shown to be higher than those of cultivated populations, no significant difference for measures of genetic variability was shown. Total genetic diversity value (H_T) was 0.342. The interlocus variation in the within-population genetic diversity (H_S) was 0.201. The proportion of total genetic variation due to differences among populations (G_ST) range was 0.414, indicating that 41.4% of the total variation was among populations. In conclusion, the RAPD technique was a useful method for discrimination between C. virosa and O. javanica. In addition, RAPD-OPB markers could further distinguish the strains from different food sources.

• Ocean Systems Engineering
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• v.14 no.2
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• pp.171-210
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• 2024

This paper focuses on the rigorous and holistic fatigue analysis of mooring chains for a deep draft semi-submersible platform in the challenging environment of the central Gulf of Mexico (GoM). Known for severe hurricanes and strong loop/eddy currents, this region significantly impacts offshore structures and their mooring systems, necessitating robust designs capable of withstanding extreme wind, wave and current conditions. Wave scatter and current bin diagrams are utilized to assess the probabilistic distribution of waves and currents, crucial for calculating mooring chain fatigue. The study evaluates the effects of Vortex Induced Motion (VIM), Out-of-Plane-Bending (OPB), and In-Plane-Bending (IPB) on mooring fatigue, alongside extreme single events such as 100-year hurricanes and loop/eddy currents including ramp-up and ramp-down phases, to ensure resilient mooring design. A detailed case study of a deep draft semi-submersible platform with 16 semi-taut moorings in 2,500 meters of water depth in the central GoM provides insights into the relative contributions of wave scatter diagram, VIMs from current bin diagram, the combined stresses of OPB/IPB/TT and extreme single events. By comparing these factors, the study aims to enhance understanding and optimize mooring system design for safety, reliability, and cost-effectiveness in offshore operations within the central GoM. The paper addresses a research gap by proposing a holistic approach that integrates findings from various contributions to advance current practices in mooring design. It presents a comprehensive framework for fatigue analysis and design optimization of mooring systems in the central GoM, emphasizing the critical importance of considering environmental conditions, OPB/IPB moments, and extreme single events to ensure the safety and reliability of mooring systems for offshore platforms.

• Development and Reproduction
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• v.10 no.1
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• pp.19-32
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• 2006

Genomic DNA isolated from two species of Korean freshwater crab(Eriocheir sinensis) and swimming crab(Portunus trituberculatus) was amplified several times by PCR reactions. The seven arbitrarily selected primers OPA-05, OPA-13, OPA-16, OPB-06, OPB-15, OPB-17 and OPD-10 were used to generate the identical, polymorphic, and specific fragments. 505 fragments were identified in the freshwater crab species, and 513 in the swimming crab from Buan: 81 specific fragments(16.0%) in the freshwater crab species and 100(19.5%) in the swimming crab. 165 identical fragments, with an average of 23.6 per primer, were observed in the freshwater crab species. 66 fragments, with an average of 9.4 per primer, were identified in the swimming crab species. The numbers of polymorphic fragments in the freshwater crab and swimming crab were 50 and 14, respectively. The oligonucleotides decamer primer OPB-17 generated identical DNA fragments, approximately 300 bp, in both the freshwater crab and swimming crab species. Compared separately, the average genetic difference was higher in the swimming crab than in the freshwater crab species. The average genetic difference was $0.726{\pm}0.004$ between the freshwater crab and swimming crab species. The dendrogram obtained by the seven primers indicates four genetic clusters: cluster 1(FRESHWATER 01), cluster 2(FRESHWATER 02, 03, 04, 05 and 06), cluster 3(FRESHWATER 07, 08, 09, 10 and 11), and cluster 4(SWIMMING 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 and 22). The shortest genetic distance displaying significant molecular difference was between individuals SWIMMING no. 18 and SWIMMING no. 17 from swimming crab(0.096). Ultimately, individual no. 02 of the freshwater crab was most distantly related to freshwater crab no. 03(genetic distance = 0.770). As stated above, the potential of RAPD-PCR to identify diagnostic markers for the identification of two crab species has been demonstrated.

• Korean Journal of Ichthyology
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• v.18 no.1
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• pp.1-11
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• 2006

Genomic DNA isolated from two geographical populations of pond-smelt (Hypomesus nipponensis) was amplified for RAPD (randomly amplified polymorphic DNA) analysis. The populations were obtained from Chungju (CJ), in the inland area, and Dangjin (DJ), in the vicinity of the West Sea in Korea. Seven arbitrarily selected primers, OPB-06, OPB-10, OPB-13, OPB-17, OPC-09, OPC-17 and OPC-20, were used to generate the shared loci, polymorphic, and specific loci. Three hundred and eighty-three loci observed per primer were identified in the CJ population, and 287 were identified in the DJ population. Among them, 91 polymorphic loci or 23.8% were polymorphic in the CJ population, and 47 (16.4%) in the DJ population. The number of shared loci observed was 198 in the CJ population and 176 in the DJ population. Forty-four and 75 specific loci were detected in the CJ and DJ populations, respectively. Especially, 99 numbers of shared loci by the two populations, with an average of 14.1 per primer, were observed in the two pond-smelt populations. The average bandsharing value between the two geographical pond-smelt populations was $0.700{\pm}0.008$, ranging from 0.600 to 0.846. Compared separately, the bandsharing value of individuals within the CJ population was higher than that of the DJ population. The dendrogram obtained using the data from the seven primers indicated three genetic clusters: cluster 1, CJ 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, and 11; cluster 2, DJ 01, 02, 03, 04, 05, 06, 07, 08, and 09; and cluster 3, DJ 10 and 11. The genetic distance between the two geographical populations ranged from 0.040 to 0.545. Thus, RAPD-PCR analysis revealed a significant genetic distance between the two pond-smelt populations.

• Development and Reproduction
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• v.23 no.3
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• pp.297-304
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• 2019

The higher fragment sizes (>2,100 bp) are not observed in the two C. spp. populations. The six oligonucleotides primers OPA-11, OPB-09, OPB-14, OPB-20, OPC-14, and OPC-18 were used to generate the unique shared loci to each tonguesole population and shared loci by the two tonguesole populations. The hierarchical polar dendrogram indicates two main clusters: Gunsan (GUNSAN 01-GUNSAN 11) and the Atlantic (ATLANTIC 12-ATLANTIC 22) from two geographic populations of tonguesoles. The shortest genetic distance displaying significant molecular difference was between individuals' GUNSAN no. 02-GUNSAN no. 01 (genetic distance=0.038). In the long run, individual no. 02 of the ATLANTIC tonguesole was most distantly related to GUNSAN no. 06 (genetic distance=0.958). These results demonstrate that the Gunsan tonguesole population is genetically different from the Atlantic tonguesole population. The potential of PCR analysis to identify diagnostic markers for the identification of two tonguesole populations has been demonstrated. As a rule, using various oligonucleotides primers, this PCR method has been applied to identify polymorphic/specific markers particular to species and geographical population, as well as genetic diversity/polymorphism in diverse species of organisms.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.279-280
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• 2002

Genomic DNA from the muscle of marsh clam (Corbicula leana) from Gochang was extracted in order to identify genetic differences and similarity by randomly amplified polymorphic DNAs-polymerase chain reaction. 3.28 of the 23.0 polymorphic bands per lane were found to be polymorphic in marsh clam. Also, about 4.34% of total polymorphic bands were either specific to marsh clam. The major common bands of 0.28 kb generated by primer OPB-15 (GGAGGGTGTT) were present in every individuals, respectively, which were polymorphic. This common bands which present in every individuals should be diagnostic of specific strains, species and/or their relatedness. Primer OPB-19 (ACCCCCGAAG) produced the highest number of specific bands, which was 12. The specific minor band of 0.07 kb was present in lane 22, which were polymorphic. Especially, only a specific band (1.35 kb) identifying individuals was observed in lane 22.

• Proceedings of the Korean Aquaculture Society Conference
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• 2002.08a
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• pp.171-172
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• 2002

Genomic DNA from the muscle of marsh clam (Corbicula leana)from Gochang was extrected in order to identify genetic differences and similarity by randomly amplified polymorphic DNAs-polymerase chain reaction. 3.28 of the 23.0 polymorphic bands per lane were found to be polymorphic in marsh clam. Also, about 4.34% of total polymorphic bands were either specific to marsh clam. The major common bands of 0.28 kb generated by primer OPB-15 (GGAGGGTGTT) were present in every individuals, respectively, which were polymorphic. This common bands which present in every individuals should be diagnostic of specific strains, species and-or their relatedness. Primer OPB-19 (ACCCCCGAAG) produced the highest number of specific bands, which was 12. The specific minor band of 0.07 kb was present in lane 22, which were polymorphic. Especially, only a specific band (1.35kg) identifying individuals was observed in lane 22.

• The Korean Journal of Malacology
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• v.25 no.1
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• pp.5-13
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• 2009

Genomic DNA isolated from two geographical ark shell (Scapharca subcrenata) populations was amplified several times by PCR reactions. The ark shell population from Daecheon (ASPD) and from Wonsan (ASPW) in the West Sea and the East Sea of Korean Peninsula, respectively, obtained. The seven arbitrarily selected primers OPA-05, OPA-11, OPB-09, OPB-11, OPB-14, OPC-18 and OPD-07 were shown to generate the loci observed per primer, shared loci by each population, specific loci, unique shared loci to each population and shared loci by the two populations which could be clearly scored. Here, 862 loci were identified in the ASPD population, and 1,191 in the ASPW population: 137 specific loci (15.9%) in the Daecheon population and 84 (7.1%) in the Wonsan population. 407 shared loci by each population, with an average of 58.1 per primer, were observed in the ASPD population. 473 shared loci by each population, with an average of 67.6 per primer, were identified in the ASPW population. The numbers of specific loci in the ASPD and ASPW population were 137 and 84, respectively. Consequently, the average bandsharing value of individuals within the ASPW population was much higher than in the ASPD population. The bandsharing value between individuals' no. 08 and no. 13 was 0.628, which was the highest measured between the two geographical populations. The dendrogram obtained by the seven primers indicated three genetic clusters: cluster 1 (DAECHEON 01-DAECHEON 11), cluster 2 (WONSAN 12 and 14) and cluster 3 (WON SAN 13, 15, 16, 17, 18, 19, 20, 21 and 22). The genetic distance between the two geographical populations ranged from 0.043 to 0.499. Especially, individual no. 10 of Daecheon population was most distantly related to no. 14 of Wonsan population (genetic distance = 0.499).