• Management Science and Financial Engineering
• /
• v.15 no.1
• /
• pp.51-69
• /
• 2009

A network model and a Genetic Algorithm (GA) is proposed to solve the simultaneous estimation of the trip distribution and traffic assignment from traffic counts in the congested networks in a logit-based Stochastic User Equilibrium (SUE). The model is formulated as a problem of minimizing a non-linear objective function with the linear constraints. In the model, the flow-conservation constraints are utilized to restrict the solution space and to force the link flows become consistent to the traffic counts. The objective of the model is to minimize the discrepancies between two sets of link flows. One is the set of link flows satisfying the constraints of flow-conservation, trip production from origin, trip attraction to destination and traffic counts at observed links. The other is the set of link flows those are estimated through the trip distribution and traffic assignment using the path flow estimator in the logit-based SUE. In the proposed GA, a chromosome is defined as a real vector representing a set of Origin-Destination Matrix (ODM), link flows and route-choice dispersion coefficient. Each chromosome is evaluated by the corresponding discrepancies. The population of the chromosome is evolved by the concurrent simplex crossover and random mutation. To maintain the feasibility of solutions, a bounded vector shipment technique is used during the crossover and mutation.

• The Plant Pathology Journal
• /
• v.40 no.2
• /
• pp.205-217
• /
• 2024

Brown rot disease, caused by Monilinia spp., poses a significant threat to pome and stone fruit crops globally, resulting in substantial economic losses during pre- and post-harvest stages. Monilinia fructigena, M. laxa, and M. fructicola are identified as the key agents responsible for brown rot disease. In this study, we employed the amplified fragment length polymorphism (AFLP) method to assess the genetic diversity of 86 strains of Monilinia spp. isolated from major stone fruit cultivation regions in South Korea. Specifically, strains were collected from Chungcheong, Gangwon, Gyeonggi, Gyeongsang, and Jeolla provinces (-do). A comparative analysis of strain characteristics, such as isolation locations, host plants, and responses to chemical fungicides, was conducted. AFLP phylogenetic classification using 20 primer pairs revealed the presence of three distinct groups, with strains from Jeolla province consistently forming a separate group at a high frequency. Furthermore, M. fructicola was divided into three groups by the AFLP pattern. Principal coordinate analysis and PERMANOVA were applied to compare strain information, such as origin, host, and fungicide sensitivity, revealing significant partition patterns for AFLP according to geographic origin and host plants. This study represents the utilization of AFLP methodology to investigate the genetic variability among M. fructicola isolates, highlighting the importance of continuous monitoring and management of variations in the brown rot pathogen.

• New & Renewable Energy
• /
• v.19 no.4
• /
• pp.46-52
• /
• 2023

Methane is the second most emitted greenhouse gas after carbon dioxide. Despite lower emissions than those of carbon dioxide, methane receives significant attention owing to its more than 20-fold higher global warming potential. Consequently, the importance of research on methanotrophic bacteria, microorganisms capable of converting methane gas into high-value materials, is increasingly emphasized. In the case of methanotrophic bacteria, knowledge on episomal plasmids that can be used for genetic engineering remains lacking, which poses significant challenges to the engineering process. The replication origin sequences of natural plasmids within methanotrophic bacteria have been predicted through in silico methods. The basic characteristics of the replication origin, such as a high A/T ratio, repetitive sequences, and proximity to proteins related to replication, have been used as criteria for identifying the replication origin. As a result, a region with a sequence of 18 base pairs repeated eight times could be identified. The putative replication origin sequence thus identified generally takes the form of iterons, but it also possesses unique features such as the length of the gap between iterons and the repetition of identical iteron sequences. This information can be valuable for future design of episomal plasmids applicable to methanotrophs.

• Korean Journal of Poultry Science
• /
• v.23 no.3
• /
• pp.145-151
• /
• 1996

The origin and present status of research and commercial production of Korean Ogol chicken are reviewed. The Yeonsan Ogol chicken was designated as a National Monument (No.265) at April 1, 1980. After that, researches have been done on the various aspects of Ogol chicken, i.e., external characteristics, growth and reproductive performance, chemical composition of egg and meat, and carcass characteristics. In addition, several genetic parameters of Ogol chicken have been estimated.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.65 no.4
• /
• pp.447-456
• /
• 2020

Peanut is an allotetraploid derived from a single recent polyploidization. Polyploidization has been reported to have caused significant loss in genetic diversity during the domestication of cultivated peanuts. Single nucleotide polymorphism (SNP)-based markers such as cleaved amplified polymorphic sequences (CAPS) derived from next-generation sequencing (NGS) have been developed and widely applied for breeding and genetic research in peanuts. This study aimed to identify the genetic diversity and population structure using 30 CAPS markers and 96 peanut accessions from five different origins. High genetic dissimilarities were detected between the accessions from Korea and those from the other three South American origins generally regarded as the origin of peanuts, while the accessions from Brazil and Argentina presented the lowest genetic dissimilarity. Based on the results of the present study, accessions from Korea have unique genetic variation compared to those from other countries, while accessions from the other four origins are closely related. Our study identified the genetic differentiation in 96 peanut accessions from five different origins, and this study also showed the successful application of SNP information derived from re-sequencing based on NGS technology.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.4
• /
• pp.404-408
• /
• 1999

To analyze the possibility for the genetic improvement at the early period at 60 days of age in tilapia, Oreochromis niloticus. Genetic parameters on eight traits, total length (TL), standrad length (SL), head length (HL), body depth (BD), body height at the origin of dorsal fin (BH1), length from the origin of dorsal fin to the origin of dorsal fin (BH2), snout length (SNL), and body weight (BW), were estimated by sib analysis. Heritabilities estimated from sire, dam and full-sib components were moderately high in all metric traits, ranged 0.08$\~$0.70, 0.22$\~$0.41 and 0.18$\~$0.55, respectively. Those of SL from sire, dam, and full-sib component were estimated as 0.13, 0.22, and 0.18, respectively, Besides BH1, BH2 also showed high heritabilities, $h^2_s$ (0.08), $h^2_d$ (0.38) and $h^2_{s+d}$ (0.23), indicating that it would be a new production-related metric trait for selection. Among the metric traits, phenotypic and genetic correlation coefficients were ranged from 0,86 to 0.97 and from 0.90 to 0.99, respectively. Thus, genetic improvement would be possible at the early growth rate by the individual selection in tilapia.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.12
• /
• pp.1696-1700
• /
• 2005

Five China native cattle breeds have been characterized by using 10 microsatellite DNA markers. The studied populations can be divided into five groups: Luxi cattle, Nanyang cattle, Jinnan cattle, Qinchuan cattle and Yanbian cattle. Allele frequencies were calculated and used for the characterization of the breeds and the study of their genetic relationships. Heterozygosity, polymorphism information content, the effective number of alleles was calculated. Nei' standard genetic distance (1978) was calculated and used for a neighbor-joining tree construction. NJ tree showed that Luxi cattle, Nanyang cattle, Jinnan cattle and Qinchuan cattle are closely related, whereas Yanbian cattle are clearly distinct from other four populations. The genetic relationship of five breeds corresponds to their history and geographic origins. This work analyzes the recent origin of these populations and contributes to the knowledge and genetic characterization of China native breeds.

• Journal of Species Research
• /
• v.1 no.1
• /
• pp.100-103
• /
• 2012

Nutria Myocastor coypus is one of a well known invasive riparian mammal found species around world from North America to Eurasia and Africa. In South Korea, feral nutrias inhabit areas from the Nakdonggang and Namgang (River) to their tributaries and Upo Wetland where they have had devastating effects on environment. Nevertheless, there has been little research about nutrias in Korea. This study is to analyze the genetic structure of the nutria population in the Upo Wetland and identify the origin of the source populations. Twenty individuals from the Upo Wetland were genotyped using 25 microsatellite loci. When compared with another introduced population, that of the Blackwater Nation Wildlife Refuge in U.S., the Upo population contains considerable genetic variations. Tests for Hardy-Weinberg equilibrium and Bayesian clustering analysis suggest the Upo population is genetically structured and has at least two source populations. This preliminary study presents the need for further in-depth studies about this species which should combine genetic and ecological studies.

• ALGAE
• /
• v.33 no.3
• /
• pp.205-214
• /
• 2018

Red algae in the genus Portieria produce secondary halogenated monoterpenes, which are effective deterrents against herbivores, as secondary metabolites. Portieria hornemannii samples from various sites contain different concentrations of these metabolites, suggesting the existence of genetic diversity and cryptic species. To evaluate the genetic diversity and species distribution of Portieria in the northwest Pacific, we analyzed rbcL sequences of samples collected from Korea, Japan, and Taiwan. The phylogenetic analysis revealed five distinct lineages at the species level. One was recognized as Portieria japonica and the others were cryptic lineages in P. hornemannii. The rbcL haplotypes of P. japonica were genetically fragmented into two subgroups of geographic origin; Korean and Japanese. The four cryptic lineages within P. hornemannii were also geographically structured at a much finer scale. These results suggest that different genetic lineages in Portieria evolved from variable microhabitats, consequently influencing secondary metabolites. Further study is required to resolve the relationships between genetic and secondary metabolite variations in Portieria.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.59 no.4
• /
• pp.492-497
• /
• 2014

Soybean (Glycine max L.) is crucial legume crop as source of high quality vegetable protein and oil, and Korea is regarded as a part of center of soybean origin. To expand the information of conserved genetic diversity, we analyzed the genetic variability of soybean collection mainly introduced Korean accessions using 75 microsatellite markers. A total of 1,503 alleles with an average value of 20.0 alleles were detected among 644 accessions. Korean collection revealed average allele number of 13.4 while Chinese, Japanese and Southeast Asian accessions showed 9.0, 5.4 and 6.5 mean alleles, respectively. Especially, Korean accessions showed more number of private allele per locus as 3.4 contrary to other geographical groups. The mean expected heterozygosity and polymorphic information content was 0.654 and 0.616, respectively, and expected heterozygosity values were not significantly distinguished according to the geographical groups. The phylogenetic dendrogram and deduced population structure based on DNA profiles of 75 SSR loci showed Korean accessions formed distinct gene pool against Chinese accessions, and could be divided into five subpopulations. Korean soybean accessions have specific genetic diversity and might be serve the valuable alleles for bio-industry as a part of the center of soybean origin.