• Journal of Educational Research in Mathematics
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• v.24 no.3
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• pp.387-407
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• 2014

This study investigeted secondary math teachers' difficulties of technology in geometry class with grounded theory by Strauss and Corbin. 178 secondary math teachers attending the professional development program on technology-based geometry teaching at eight locations in January 2014, participated in this study with informed consents. Data was collected with an open-ended questionnaire survey. In line with grounded theory, open, axial and selective coding were applied to data analysis. According to the results of this study, teachers were found to experience resistance in using technology due to new learning and changes, with knowledge and awareness of technology effectively interacting to lessen such resistance. In using technology, teachers were found to go through the 'access-resistance-unaccepted use-acceptance' stages. Teachers having difficulties in using technology included the following four types: 'inaccessible, denial of acceptance, discontinuation of use, and acceptance 'These findings suggest novel perspectives towards teachers having difficulties in using technology, providing implications for teachers' professional development.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.1
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• pp.1-9
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• 1986

This is the third part of the four-part paper describing the development of a packet-switched computer communication network named the KORNET. In this paper we describe the design and implementation of the X.25 protocol connecting packet mode data terminal equipments(PDTE's) with data circuit terminating equipments(DCE's). In the KORNET, the X.25 protocol has been implemented on the line processing module-A(LPMA) of the network node processor(NNP). In the implementation of X.25, we have divided the software module according to the service function, and have determined the the rules that interact between the modules. Each layer protocol has been developed using the technique of the finite state machine. Before the actual coding of softwares, we hafve used formal software development tools based on the specification and description language (SDL) and program design languate (PDL) recommended by the CCITT. In addition, for the efficient operation of the X.25 protocol system we have analyzed the system performance and the service scheduling method of each module. The results will also be given.

• International Journal of Oncology
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• v.55 no.4
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• pp.960-972
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• 2019

MicroRNAs (miRNAs/miRs) are a class of small non-coding RNAs that play pivotal roles in cancer physiology as important epigenetic regulators of gene expression. Several miRNAs have been previously discovered that regulate the proliferation of the colorectal cancer (CRC) cell line HCT116. In the present study, one of these miRNAs, miR-5191, was characterized as a tumor suppressor in CRC cells. Transfection with miR-5191 led to a significant decrease in cell proliferation, invasiveness, tumor sphere-forming ability and tumor organoid growth, as determined via trypan blue, Transwell, sphere culture and organoid culture assays, respectively. Flow cytometric analyses revealed that miR-5191 induced the cell cycle arrest and apoptosis of CRC cells. Additionally, the expression of miR-5191 was downregulated in CRC tumor tissues compared with in normal tissues, as measured by reverse transcription-quantitative PCR analysis. Ribosomal protein S6 kinase β1 (RPS6KB1) was identified as a direct target of miR-5191. Ectopic expression of RPS6KB1 suppressed the function of miR-5191. Intratumoral injection of miR-5191 mimic suppressed tumor growth in HCT116 xenografts. These findings suggested a novel tumor-suppressive function for miR-5191 in CRC, and its potential applicability for the development of anticancer miRNA therapeutics.

• Molecules and Cells
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• v.25 no.4
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• pp.467-478
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• 2008

Simple sequence repeats (SSRs) and interSSR (ISSR) marker systems were used in this study to reveal genetic changes induced by artificial selection for short/long larval duration in the tropical strain Nistari of the silkworm Bombyx mori. Artificial selection separated longer larval duration (LLD) ($29.428{\pm}0.723days$) and shorter larval duration (SLD) ($22.573{\pm}0.839days$) lines from a base, inbred population of Nistari (larval span of $23.143{\pm}0.35days$). SSR polymorphism was observed between the LLD and SLD lines at one microsatellite locus, Bmsat106 ($CA_7$) and at two loci of 1074 bp and 823 bp generated with the ISSR primer UBC873. Each of these loci was present only in the LLD line. The loci segregated in the third generation of selection and were fixed in opposite directions. In the $F_2$ generation of the $LLD{\times}SLD$ lines, the alleles of Bmsat106 and $UBC873_{1074bp}$ segregated in a 1:1 ratio and the loci were present only in the LLD individuals. $UBC873_{823bp}$ was homozygous. Single factor ANOVA showed a significant association between the segregating loci and longer larval duration. Together, the two alleles contributed to an 18% increase in larval duration. The nucleotide sequences of the $UBC873_{1074bp}$ and $UBC873_{823bp}$ loci had 67% A/T content and consisted of direct, reverse, complementary and palindromic repeats. The repeats appeared to be "nested" (59%) in larger repeats or as clustered elements adjacent to other repeats. Of 203 microsatellites identified, dinucleotides (67.8%) predominated and were rich in A/T and T/A motifs. The sequences of the $UBC873_{1074bp}$ and $UBC873_{823bp}$ loci showed similarity (E = 0.0) to contigs located in Scaffold 010774 and Scaffold 000139, respectively, of the B. mori genome. BLASTN analysis of the $UBC873_{1074bp}$ sequence showed significant homology of (nt.) 45-122 with upstream region of three exons from Bombyx. The complete sequence of this locus showed ~49% nucleotide conservation with transposon 412 of Drosophila melanogaster and the Ikirara insertions of Anopheles gambiae. The A + T richness and lack of coding potential of these small loci, and their absence in the SLD line, reflect the active process of genetic change associated with the switch to short larval duration as an adaptation to the tropics.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.1
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• pp.67-83
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• 2023

The social venture start-up phenomenon is found from the perspectives of social enterprise and for-profit enterprise. This study aims to fundamentally explore the start-up phenomenon of social ventures from these two perspectives. Considering the lack of prior research that researched both social and commercial perspectives at the same time, this paper analyzed using grounded theory approach of Strauss & Corbin(1998), an inductive research method that analyzes based on prior research and interview data. In order to collect data for this study, eight corporate representatives currently operating social ventures were interviewed and data and phenomena were analyzed. This progressed to a theoretical saturation where no additional information was derived. The analysis results of this study using the grounded theory approach are as follows. As a result of open coding and axial coding, 147 concepts and 70 subcategories were derived, and 18 categories were derived through the final abstraction process. In the selective coding, 'expansion of social venture entry in the social domain' and 'expansion of social function of for-profit companies' were selected as key categories, and a story line was formed around this. In this study, we saw that it is necessary to conduct academic research and analysis on the competitive factors required for companies that pursue the values of two conflicting relationships, such as social ventures, to survive with competitiveness. In practice, concepts such as collaboration with for-profit companies, value combination, entrepreneurship competency and performance improvement, social value execution competency reinforcement, communication strategy, for-profit enterprise value investment, and entrepreneur management competency were derived. This study explains the social venture phenomenon for social enterprises, commercial enterprises, and entrepreneurs who want to enter the social venture field. It is expected to provide the implications necessary for successful social venture startups.

• Radiation Oncology Journal
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• v.17 no.2
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• pp.151-157
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• 1999

Purpose : By sequencing the Erpressed Sequence Tags of human 걸ermal papilla CDNA library, we identified a clone named K872 of which the expression decreased during differentiation of HL6O cell line. Materials and Methods : K872 plasmid DNA was isolated according to QIA plasmid extraction kit (Qiagen GmbH, Germany). The nucleotide sequencing was performed by Sanger's method with K872 plasmid DNA. The most updated GenBank EMBL necleic acid banks were searched through the internet by using BLAST (Basic Local Alignment Search Tools) program. Nothern bots were performed using RNA isolated from various human tissues and cancer cell lines. The gene expression of the fusion protein was achieved by His-Patch Thiofusicn expression system and the protein product was identified on SDS-PAGE. Results : K872 clone is 1006 nucleotides long, and has a coding region of 675 nucleotides and a 3' non-coding region of 280 nucleotides. The presumed open reading frame starting at the 5' terminus of K872 encodes 226 amino acids, including the initiation methionine residue. The amino acid sequence deduced from the open reading frame of K872 shares $70\%$, identity with that of rat glutathione 5-transferase kappa 1 (rGSTKl). The transcripts were expressed in a variety of human tissues and cancer cells. The levels of transcript were relatively high in those tissues such as heart, skeletal muscle, and peripheral blood leukocyte. It is noteworthy that K872 was found to be abundantly expressed in coloreetal cancer and melanoma cell lines. Conclusion : Homology search result suggests that K872 clone is the human homolog of the rGSTK1 which is known to be involved in the resistance of cytotoxic therapy. We propose that meticulous functional analysis should be followed to confirm that.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1178-1187
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• 1998

Background : Recently the incidence of tuberculosis is increasing in many countries and control of the disease is further threatened by the emergence of multi-drug resistant tuberculosis. So rapid detection of drug resistance is very important. Pyrazinamide (PZA) is a first-line chemotherapeutic agent for tuberculosis. Now in Korea, we perform PZase activity test instead of actual pyrazinamide susceptibility test for the detection of PZA resistant M. tuberculosis. Recently the pncA gene, encoding the PZase of M. tuberculosis, was completely sequenced. And it was reported that the mutation of pncA gene would be associated with PZA resistance of M. tuberculosis. Therefore we performed this study to evaluate the possibility for the rapid detection of PZA resistant M. tuberculosis using PCR-SSCP of pncA gene. Method : 44 cultured clinical isolates of M. tuberculosis, BCG Tokyo strain. BCG French strain, and one M. bovis isolate were studied. We used H37Rv as the reference strain, The PZase activity test was done at the reference laboratory of Korean Tuberculosis Institute. DNA was extracted by bead-beater method and 561 bp fragment including pncA gene was amplified by PCR. The PCR product were digested by BstB I enzyme. SSCP was done using MDE gel. Of the 44 strains of M. tuberculosis, 22 strains were PZase-positive and other 22 strains were PZase negative. Results : Of the 22 PZase positive strains, 18 strains(82%) showed the same mobility compared with that of H37Rv and 4(18%) showed different mobility. Of the 22 PZase-negative strains, 19(86%) strains showed the same mobility pattern compared with that of H37Rv and 3(14%) showed different mobility. Naturally PZA-resistant BeG-French strain, BCG-Tokyo strain, and one M. bovis isolate showed the same band pattern each other, but their mobility were different from that of H37Rv. The results of PZase activity test and PCR-SSCP of pncA of M. tuberculosis were statistically significantly correlated each other (p<0.01). Conclusion : The PCR-SSCP after BstB I restriction of pncA gene of M. tuberculosis may be a useful method for the rapid detection of PZA-resistant M. tuberculosis.

• Journal of Korea Entertainment Industry Association
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• v.13 no.5
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• pp.263-271
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• 2019

The recent phenomenon of job "Miss Match", which is inconsistent with knowledge in the demand of educational training institutes and industries, has spread to an increase in private education costs for reeducation and employment of new hires, resulting in weak individual job competency and poor employment capability, as well as economic and material waste at the national level. To compensate for these problems, the National Competency Standards(NCS), which are available immediately in practice and look for a standard point of national job competency with the aim of fostering human resources sought by industries, were developed, and even the NCS-based qualification system was launched in line with the stream of times. This study is intended to look into the importance and priority of competency units and competency unit elements at the NCS-based qualification L3 level in the skin care field for an overall check of the NCS-based qualification level at a time when educational institutes are organizing and operating the school curriculums according to the NCS and NCS-based qualification level. And it is attempted to provide basic data for the development of curriculum in fostering professional human resources required by industries. To analyze the needs for competency units and competency unit elements at the L3 level, a survey using AHP method was carried out to a group of field experts and a group of education experts. In addition, the SPSS(Statistical Package for Social Science) ver. 21.0 and Expert Choice 2000, an AHP-only solution was used to do statistical processing through the processes of data coding and data cleaning. The findings showed that there was a partial difference of opinion between a group of field experts and a group of education experts. This indicates that the inconsistencies between educational training institutes and industrial sites should be resolved at this time of change with the aim of fostering field customized human resources with professional skills. Consequently, the solution is to combine jobs at industrial sites and standardized educations of educational institutes with human resources required at industrial sites.

• The Journal of Korean Association of Computer Education
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• v.11 no.1
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• pp.57-64
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• 2008

This paper presents a web-based virtual educational system for Java language, which consists of a management system named Java Web Player (JWP) and creative multimedia contents for the lectures of Java language. The JWP is a Java application program free from security problems by the Java Web Start technologies that supports an integrated learning environment including three important learning procedures: Java concept learning process, programming practice process and assessment process. On-line voice presentation and its related texts together with moving images are synchronized for efficiently conveying creative contents to learners. Furthermore, a simple and useful compiler is included in the JWP for providing user-friendly language practice environment enabling such as coding, editing, executing, and debugging Java source files on the Web. Finally, simple multiple choices are given suddenly to the learners while they are studying through the JWP and the test results are displayed on the message box. In order to show the validity of the proposed virtual educational system we analysed and assessed the learners' academic performance on the five quizzes for one semester.

• Environmental Analysis Health and Toxicology
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• v.31
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• pp.10.1-10.8
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• 2016

Objectives Aromatase inhibitors that block estrogen synthesis are a proven first-line hormonal therapy for postmenopausal breast cancer. Although it is known that standardized extract of Ginkgo biloba (EGb761) induces anti-carcinogenic effects like the aromatase inhibitors, the effects of EGb761 on steroidogenesis have not been studied yet. Therefore, the effects of EGb761 on steroidogenesis and aromatase activity was studied using a H295R cell model, which was a good in vitro model to predict effects on human adrenal steroidogenesis. Methods Cortisol, aldosterone, testosterone, and $17{\beta}$-estradiol were evaluated in the H295R cells by competitive enzyme-linked immunospecific assay after exposure to EGb761. Real-time polymerase chain reaction were performed to evaluate effects on critical genes in steroid hormone production, specifically cytochrome P450 (CYP11/ 17/19/21) and the hydroxysteroid dehydrogenases ($3{\beta}$-HSD2 and $17{\beta}$-HSD1/4). Finally, aromatase activities were measured with a tritiated water-release assay and by western blotting analysis. Results H295R cells exposed to EGb761 (10 and $100{\mu}g/mL$) showed a significant decrease in $17{\beta}$-estradiol and testosterone, but no change in aldosterone or cortisol. Genes (CYP19 and $17{\beta}$-HSD1) related to the estrogen steroidogenesis were significantly decreased by EGb761. EGb761 treatment of H295R cells resulted in a significant decrease of aromatase activity as measured by the direct and indirect assays. The coding sequence/Exon PII of CYP19 gene transcript and protein level of CYP19 were significantly decreased by EGb761. Conclusions These results suggest that EGb761 could regulate steroidogenesis-related genes such as CYP19 and $17{\beta}$-HSD1, and lead to a decrease in $17{\beta}$-estradiol and testosterone. The present study provides good information on potential therapeutic effects of EGb761 on estrogen dependent breast cancer.