• Korean Journal of Plant Taxonomy
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• v.43 no.3
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• pp.181-187
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• 2013

Genetic variation in Asaum misandrum, a woodland herb in Korea, was investigated based on allozyme analysis with starch gel electrophoresis. All of previously reported populations in Korea were sampled and seven loci from six enzymes were analyzed. Overall genetic variation of A. misandrum population showed considerably high levels of genetic variation within the species (A = 2.05, P = 71.4, $H_E$ = 0.294). A positive $F_{IS}$ value of A. misandrum indicated overall deficiency of heterozygotes, and a low $F_{ST}$ value (0.112) meant very little differentiation among populations. Factors contributing to the high levels of genetic diversity found within populations of A. misandrum include population maintenance via wide distribution range from Korea to Japan and primarily outcrossing breeding system. Although it showed moderate genetic diversity level, most habitats of the species were scattered and discontinuous. Besides, low numbers of individuals were found in the most habitats and individuals are collected frequently from the wild due to the unique shape of the flowers as well as the rarity of the species. Thus, there is a need to set up a reasonable conservation strategies including the maintenance mechanism of genetic diversity of A. misandrum.

• Applied Chemistry for Engineering
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• v.19 no.6
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• pp.592-599
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• 2008

Oil sands had not received enough attention due to high production cost. However, as oil price significantly increases, oil sands are receiving more and more interest as unconventional crude oil. The value and applicability of oil sands can be enhanced by upgrading oil sands bitumen to produce synthetic crude oil (SCO). This study analyzed 213 oil sands upgrading patents applied between 1969 and 2006 in US, Canada, Japan, Europe, and Korea. The upgrading technologies could be classified into 9 detailed technologies; hydrocracking, coking, thermal cracking, deasphalting, supercritical technology, bio-technology, hydrotreating, gasification, and others. The number of patents applied for oil sands upgrading increased after 1970, reached a maximum in the early 1980, and slowly increases again in recent years. Korea has a lack of technologies for oil sands. Therefore, the technologies for oil sands production and application, specially, upgrading technologies based on accumulated oil refinery technologies need to be developed to increase self-development ratio of energy resource.

• The Korean Journal of Applied Statistics
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• v.29 no.6
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• pp.1117-1128
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• 2016

In genetic association studies with high-dimensional genomic data, regularization procedures based on penalized likelihood are often applied to identify genes or genetic regions associated with diseases or traits. A network-based regularization procedure can utilize biological network information (such as genetic pathways and signaling pathways in genetic association studies) with an outstanding selection performance over other regularization procedures such as lasso and elastic-net. However, network-based regularization has a limitation because cannot be applied to high-dimension genomic data with a group structure. In this article, we propose to combine data dimension reduction techniques such as principal component analysis and a partial least square into network-based regularization for the analysis of high-dimensional genomic data with a group structure. The selection performance of the proposed method was evaluated by extensive simulation studies. The proposed method was also applied to real DNA methylation data generated from Illumina Innium HumanMethylation27K BeadChip, where methylation beta values of around 20,000 CpG sites over 12,770 genes were compared between 123 ovarian cancer patients and 152 healthy controls. This analysis was also able to indicate a few cancer-related genes.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.1
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• pp.87-95
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• 1996

A new design scheme for the fuzzy pattern matching classifier (FPMC) is proposed. in conventional design of FPMC, there are no exact information about the membership function of which shape and number critically affect the performance of classifier. So far, a trial and error or heuristic method is used to find membership functions for the input patterns. But each of them have limits in its application to the various types of pattern recognition problem. In this paper, a new method to find the appropriate shape and number of membership functions for the input patterns which minimize classification error is proposed using genetic algorithms(GAs). Genetic algorithms belong to a class of stochastic algorithms based on biological models of evolution. They have been applied to many function optimization problems and shown to find optimal or near optimal solutions. In this paper, GAs are used to find the appropriate shape and number of membership functions based on fitness function which is inversely proportional to classification error. The strings in GAs determine the membership functions and recognition results using these membership functions affect reproduction of next generation in GAs. The proposed design scheme is applied to the several patterns such as tire tread patterns and handwritten alphabetic characters. Experimental results show the usefulness of the proposed scheme.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.2
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• pp.110-119
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• 2016

Purpose: This study is aimed to assess changes of stress distribution dependent on different connection lengths and placement of the fixture top relative to the ridge crest. Materials and methods: The internal-conical connection implant which has a hexagonal anti-rotation index was used for FEM analysis on stress distribution in accordance with connection length of fixture-abutment. Different connection lengths of 2.5 mm, 3.5 mm, and 4.5 mm were designed respectively with the top of the fixture flush with residual ridge crest level, or 2 mm above. Therefore, a total of 6 models were made for the FEM analysis. The load was 170 N and 30-degree tilted. Results: In all cases, the maximum von Mises stress was located adjacent to the top portion of the fixture and ridge crest in the bone. The longer the connection length was, the lower the maximum von Mises stress was in the fixture, abutment, screw and bone. The reduction rate of the maximum von Mises stress depending on increased connection length was greater in the case of the fixture top at 2 mm above the ridge crest versus flush with the ridge crest. Conclusion: It was found that the longer the connection length, the lower the maximum von Mises stress appears. Furthermore, it will help prevent mechanical or biological complications of implants.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.2
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• pp.94-102
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• 1998

Temporal changes, density, calcimass, mode of occurrence, size-frequency histogram and survivorship curves were studied for the molluscan death assemblages on a macrotidal flat, Inchon, Korea. The living and death assemblages were compared on the basis of the taxonomic compositions and their numerical abundances. A total of 28 species (16 taxa in gastropods and 12 in bivalves) were identified. Most of the dead shells were the species inhabiting that intertidal mud flat. Species diversity was higher in gastropods than in bivalves. Seasonal variation of the calcimass was influenced by the mactrid bivalve, Mactra veneriformis. Shell-boring naticid gastropods preferred selecting the umbo areas of various valves. Size-frequency distribution and size-specific survivorship curves were analyzed for the dominant species. Survivorship curve of the tellinid bivalve, Morella rutila was convex-up in shape, which is congruent with the expected equilibrium condition but indicates higher mortality in winter. Whereas the survivorship curves of Mactra veneriformis and Reticunassa festiva were semi convex-up with dual modes, suggesting a disequilibrium due to the changes in recruitment and seasonal mortality. This study suggests that the dead shell assemblages may be useful in getting population information like live molluscan assemblages, if solved for several problems related to taphonomic processes.

• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.115-123
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• 2013

Food safety management should be based on scientific evidences. FAO and WHO presented risk analysis as one of four principles in food safety management. WTO also admits the self safety regulation only when it is made on the basis of risk assessment. Without scientific analysis, tracing and eliminating the cause of food poisoning is impossible. Research and development plays a key role to produce scientific evidences. The Korean government ran over 40 programs in 11 agencies from 2008 to 2010. However, there is no statistics on food safety R&D at present. In this research, food safety projects conducted from 2008 to 2010 are listed up by means of analysing National Science and Technology Information Service (NTIS). The analytical criteria are the name of programs, national standard classification of science and technology, and keywords. As result, Korea Food and Drug Administration, Ministry for Food, Agriculture, Forestry and Fisheries, and Rural Development Administration play major role in the food safety R&D. The portion of more than one year projects should rise up in order to achieve the data for risk assessment, which is strongly required to improve. Besides, the research should be deeper so as to publish more SCI papers. The R&D portfolio should be changed in direction to raise up the portion of biological hazards such as norovirus. In order to do so, a large number of food safety programs should be emerged. The categories of food safety management and the hygiene/quality management of the agricultural and livestock products in the national standard classification of science and technology should be emerged because they are set up reflecting agencies' interests in spite of few differences between them.

• Weed & Turfgrass Science
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• v.4 no.1
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• pp.18-25
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• 2015

A universal DNA barcoding for agricultural noxious weeds is a powerful technique for species identification without morphological knowledge, by using short sections of DNA from a specific region of the genome. Two standard barcode markers, chloroplast rbcL and matK, and a supplementary nuclear ribosomal Internal Transcribed Spacer (ITS) region were used to examine the effectiveness of the markers for Pooideae barcoding using 163 individuals of 29 taxa across 16 genera of Korean Pooideae. The rbcL and ITS revealed a good level of amplification and sequencing success while matK did not. Barcode gaps were 78.6% for rbcL, 96.2% for matK, and 91.7% for ITS, respectively. Resolving powers were 89.3% for rbcL, 92.3% for matK, and 79.1% for ITS. The matK obtained the best both barcode gap and resolving power. However, it should be considered not to employ matK for Pooideae barcode because of low rate of PCR amplification and sequencing success. As a single DNA marker, rbcL and ITS were reasonable for Pooideae barcode. Barcode gap and resolving power were increased when ITS was incorporated into the rbcL. The barcode sequences were deposited to the National Center for Biotechnology Information (NCBI) database for public use.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.2
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• pp.79-85
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• 2009

Net radiation ($R_N$) is a driving force of biological and physical processes between the surface and the atmosphere and its knowledge is critical to weather forecasting and water resource management. The measurement of $R_N$ is, however, scarce and it is typically estimated from an empirical relationship. This study presented two different methods of $R_N$ estimation over three major plant functional types (i.e., a deciduous forest, a coniferous forest, and a farmland) in Korea. One is a linear regression method between $R_N$ and solar radiation and the other is a radiation balance method. The two methods were examined using the data collected in 2008 at the three sites. Based on the linear regression method over a year, $R_N$ was 70% of the incoming shortwave radiation ($R_S{\downarrow}$) for a deciduous forest, 79% for a coniferous forest, and 64% for a farmland, indicating that the relationship was plant functional type-specific. For the radiation balance method, the inclusion of longwave radiation component slightly improved $R_N$ estimations. Overall, there was a good agreement between the observed and the estimated $R_N$ from both methods, indicating a reliable applicability of the two methods in estimating $R_N$.

• Analytical Science and Technology
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• v.26 no.5
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• pp.307-314
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• 2013

Selenium exists in various forms of chemical species. The activity and bioavailability is strongly dependent on its chemical form and concentration. Consequently the information on each selenium species and its concentration must be exactly determined for the food we take in. In this study, selenium species in seafood were separated and quantified by RP (reversed phase) HPLC (high performance liquid chromatography) coupled with ICP-MS (inductively coupled plasma mass spectrometry) using post-column isotope dilution. $^{79}Br$, which interferes on $^{80}Se$, has mostly been removed by solid phase extraction and then mathematical correction has been applied for the more accurate correction. The experimental result for CRM (certified reference material) DOLT-4 agreed well with the certified value but each selenium species could not be compared. SeCys (selenocysteine) and SeMet (selenomethionine) were the major species detected in seafood such as belt fish, spanish mackerel, and squid that have been serving as Korean diet. The concentrations found in Korean sea food for SeCys and SeMet were in the range of 0-661.6 mg/kg and 137.3-462.7 mg/kg, respectively.