• School Mathematics
• /
• v.9 no.3
• /
• pp.427-445
• /
• 2007

This study presents the results of a case study that investigated a seventh grader's fractional reasoning related to multiplicative reasoning. In addition, by employing domain analysis and taxonomic analysis for analyzing qualitative data, I show how a qualitative methodology was used for the data collected by teaching experiment methodology. The study identifies three distinct issues that emerged as the student engaged in solving fraction problems: a view of fractions as operations vs. results, the issue of units, and mixed numbers vs. improper fractions. These three issues have instructional implications in that each of them is critical in developing multiplicative reasoning and investigating how they relate to each other suggests a way to improve multiplicative reasoning in fractional contexts.

• Proceedings of the Zoological Society Korea Conference
• /
• 1997.04a
• /
• pp.27-27
• /
• 1997

No Abstract, See Full Text

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.26 no.3
• /
• pp.263-276
• /
• 2021

Marine benthic organisms have been used as the indicators for the environment assessment and recently considered as a very important component in the biodiversity and ecosystem restoration. In Korean waters, the quantitative data on marine benthos was used as one of major components for the marine pollution assessment for 50 years since 1970s. The species identification which is an important factor for the quantitative biological data was mainly performed by the marine benthic ecologists. This leads to the deterioration of the data quality on marine benthos from the misidentication of major taxonomic groups due to the lack of taxonomic expertise in Korea. This taxonomic problem has not been solved until now and remains in most data from national research projects on the marine ecosystems in Korean waters. Here we introduce the quality assurance and control (QA/QC) system for the marine biological data in UK, that is, NMBAQC (Northeast Atlantic Marine Biological Analytic and Quality Control) Scheme which has been performed by private companies to solve similar species identification problems in UK. This scheme asks for all marine laboratories which want to participate to any national monitoring programs in UK to keep their identification potency at high level by the internal quality assurance systems and provides a series of taxonomic workshops and literature to increase their capability. They also performs the external quality control for the marine laboratories by performing the Ring Test using standard specimens on various faunal groups. In the case of Korea, there are few taxonomic expertise in two existing national institutions and so they can't solve the taxonomic problems in marine benthic fauna data. We would like to provide a few necessary suggestions to solve the taxonomic problems in Korean marine biological data in short-terms and long-terms: (1) the identification of all dominant species in marine biological data should be confirmed by taxonomic expertise, (2) all the national research programs should include taxonomic experts, and (3) establishing a private company, like the Korea marine organism identification association (KMOIA), which can perform the QA/QC system on the marine organisms and support all Korean marine laboratories by providing taxonomic literature and species identification workshops to enhance their potency. The last suggestion needs more efforts and time for the establishment of that taxonomic company by gathering the detailed contents and related opinions from diverse stakeholders in Korea.

• Korean Journal of Plant Taxonomy
• /
• v.39 no.3
• /
• pp.143-169
• /
• 2009

To confirm the taxonomic identity of taxa described by $L{\acute{e}}veill{\acute{e}}$, H. H. A, a French plant taxonomist, in the serial papers of Decades plantarum novarum based on the collections of Fathers Faurie and Taquet from the Korean peninsula, we examined the numerous references that contained taxonomic opinions about $L{\acute{e}}veill{\acute{e}}^{\prime}s$ taxa. Among them, 146 taxa were confirmed as conspecific with other existing taxa. Of them, 79 taxa, including Ajuga devestita, were listed as a synonym of only one species. Sixty-seven taxa, including Bidens robertianifolia, were listed as synonyms of two or more species according to taxonomists. Eight taxa, including Aconitum coreanum, were considered illegitimate names because of later homonym, or other problems. Five taxa, including Rhododendron hallaisanense, were treated either as distinct or conspecific taxa depending on taxonomists.

• ALGAE
• /
• v.35 no.3
• /
• pp.293-301
• /
• 2020

The applications of DNA barcoding have a wide range of uses, such as in taxonomic studies to help elucidate cryptic species and phylogenetic relationships and analyzing environmental samples for biodiversity monitoring and conservation assessments of species. After obtaining the DNA barcode sequences, sequence similarity-based homology analysis is commonly used. This means that the obtained barcode sequences are compared to the DNA barcode reference databases. This bioinformatic analysis necessarily implies that the overall quantity and quality of the reference databases must be stringently monitored to not have an adverse impact on the accuracy of species identification. With the development of next-generation sequencing techniques, a noticeably large number of DNA barcode sequences have been produced and are stored in online databases, but their degree of validity, accuracy, and reliability have not been extensively investigated. In this study, we investigated the extent to which the amount and types of erroneous barcode sequences were deposited in publicly accessible databases. Over 4.1 million sequences were investigated in three largescale DNA barcode databases (NCBI GenBank, Barcode of Life Data System [BOLD], and Protist Ribosomal Reference database [PR2]) for four major DNA barcodes (cytochrome c oxidase subunit 1 [COI], internal transcribed spacer [ITS], ribulose bisphosphate carboxylase large chain [rbcL], and 18S ribosomal RNA [18S rRNA]); approximately 2% of erroneous barcode sequences were found and their taxonomic distributions were uneven. Consequently, our present findings provide compelling evidence of data quality problems along with insufficient and unreliable annotation of taxonomic data in DNA barcode databases. Therefore, we suggest that if ambiguous taxa are presented during barcoding analysis, further validation with other DNA barcode loci or morphological characters should be mandated.

• Journal of Plant Biology
• /
• v.22 no.4
• /
• pp.115-133
• /
• 1979

Pollen grains of 26 genera and 62 species of the Lythraceae were investigated by means of light microscopy. The result reveals that the family is divided into three pollen groups which are characterized by having a non-, 3- and 6-pseudocolpate aperture. The palynological study suggests a revision of the subfamilial division. Some taxonomic problems between the genera were discussed on the pollen morphology.

• Journal of the Korean School Mathematics Society
• /
• v.14 no.2
• /
• pp.143-161
• /
• 2011

Mathematics PBL, which has recently attracted much attention, is a teaching and learning method to increase mathematical ability and help learning mathematical concepts and principles through problem solving using mathematical knowledge the students have. In spite of the attention, however, the implementations are yet significant. In this study, we worked to find the needs of mathematics teachers for mathematics PBL implementation. The methods of this study are taxonomic analysis and componential analysis by using cards depth interviewing. As a result, mathematics teachers' needs are to consider how to develop the mathematics PBL problems and how to make progress.

• Journal of Plant Biology
• /
• v.29 no.4
• /
• pp.329-340
• /
• 1986

This study is attemped to discuss the taxonomic significances as have been raised up to now in the study of Lauraceous inflorescence. Lauraceous inflorescences are recognized as panicle, umbel, dichasium, or fascicle by various investigators. Reconsidering the inflorescence or existence of involucre, which has been accepted as important character in the present classification system, it is assumed that the study about them has not so far carried out a deliberate analysis over inflorescent morphology, nor has recognized the existence of involucre. Furthermore, all the materials examined in this study have fugacious or persistent involucres which are leafy, scaly or membraneous. Therefore, it was found that the kinds, fugacity or persistency of involucres are significant in the problems of classification of Laureaceae. Korean Lauraceous inflorescence has evolved into the direction of continuous reduction in its peduncle: from compound dichasium to capitate umbel.

• The Korean Journal of Malacology
• /
• v.26 no.2
• /
• pp.171-175
• /
• 2010

Korean cephalopods only recorded with Korean name in the literature were reviewed to solve confusions in use of their Korean name for taxonomic studies of cephalopods in Korea, and to prepare a basic check list for standardizing total cephaolopods fauna of Korea in the future. A total 38 cephalopods species with Korean names were listed in this study; 14 species in order Sepioidea, 17 species in Teuthoidea, 7 species in Octopoda. The etymology and some problems of Korean names of cephalopods occurring in Korea, and the useable rules for naming cephalopods with Korean words are recommended and discussed.

• Korean Journal of Plant Resources
• /
• v.12 no.4
• /
• pp.324-339
• /
• 1999

Morphological reinvestigation, external characters and discriminant functional analysis(44 qualitative characters) were examined on 6 taxa of Korean Ophelia, including 5 taxa distributed in south Korea, and one taxon considered to be the variation type of Ophelia wilfordi in order to clarify the limit of intersection and interspecies. And to establish the taxonomic position. One taxon distributed in north Korea was included in the description of species by observation of herbarium specimen of the University of Tokyo in Japan. The two sections were successfully distinguished by internal structure of ovary, morphology of nectary, number of corolla lobe and calyx lobe, and species were also distinguished by morphology of cauline leaf, and color and spot of corolla, respectively. The variation type of Ophelia wilfordi was not distinguished with other species except for absent or present of purple spot in corolla lobe. The results of the discriminal functional analysis indicated that characters of corolla were the most important qualitative characters to distinguish the Ophelia taxa, and morphology of seed and seed coat was useful characters to distinguish taxa higher than species. Therefore the difficult problems of identification of species were successfully solved, and the taxonomic position in intrageneric level was clarified on Korean Ophelia.