• Asian-Australasian Journal of Animal Sciences
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• v.28 no.6
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• pp.876-887
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• 2015

Dicer, an ribonuclease type III type endonuclease, is the key enzyme involved in biogenesis of microRNAs (miRNAs) and small interfering RNAs (siRNAs), and thus plays a critical role in RNA interference through post transcriptional regulation of gene expression. This enzyme has not been well studied in the Indian water buffalo, an important species known for disease resistance and high milk production. In this study, the primary coding sequence (5,778 bp) of bubaline dicer (GenBank: AB969677.1) was determined and the bubaline Dicer1 biocomputationally characterized to determine the phylogenetic signature among higher eukaryotes. The evolutionary tree revealed that all the transcript variants of Dicer1 belonging to a specific species were within the same node and the sequences belonging to primates, rodents and lagomorphs, avians and reptiles formed independent clusters. The bubaline dicer1 is closely related to that of cattle and other ruminants and significantly divergent from dicer of lower species such as tapeworm, sea urchin and fruit fly. Evolutionary divergence analysis conducted using MEGA6 software indicated that dicer has undergone purifying selection over the time. Seventeen divergent sequences, representing each of the families/taxa were selected to study the specific regions of positive vis-$\grave{a}$-vis negative selection using different models like single likelihood ancestor counting, fixed effects likelihood, and random effects likelihood of Datamonkey server. Comparative analysis of the domain structure revealed that Dicer1 is conserved across mammalian species while variation both in terms of length of Dicer enzyme and presence or absence of domain is evident in the lower organisms.

• Environmental and Resource Economics Review
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• v.14 no.1
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• pp.1-24
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• 2005

One of the most important factors that determine the quality of a stated preference study is questionnaire design. This study introduces strategies for enhancing the rationality and testing for the validity of choice experiments(CE) using "example" choice questions that mimic the main choice questions. From the case study of WTP for reduced radon radiation exposures in the home, the study found that screening out irrational responses, 12% of the effective responses, resulted in a meaningful increase in model fit. Meanwhile the study tested for anchoring effects, as a way of confirming the divergent validity of the study, by looking at equality of models estimated for two subsamples. The overall test results were mixed. The pros and cons of the questionnaire design strategy employed are also reported.

• Journal of Energy Engineering
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• v.21 no.3
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• pp.237-242
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• 2012

This study presents numerical solutions of the two-dimensional Navier-Stokes equations for supersonic unsteady flow in a convergent-divergent nozzle with a isolator. The TVD scheme in generalized coordinates is employed in order to calculate the moving shock waves caused by thermal choking. We discuss on transient characteristics, unstart phenomena, fluctuations of specific thrust caused by thermal choking and effects of isolator. The adverse pressure gradient caused by heat addition brings about separation of the wall boundary layers and formation of the oblique shock wave that proceed to upstream. The proceeding speed of the oblique shock wave to upstream direction for the convergent-divergent nozzle with isolator is lower than that for the nozzle without isolator.

• Archives of design research
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• v.14 no.3
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• pp.77-85
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• 2001

This paper focuses on the idea development as a creative thinking process for design innovation. The process of thinking has the thinking structures of abduction and transformation. After we had studied the design thought, we found a structure of a thinking system, and created a creative thinking model with this. Using job analysis, we examined the duster of design jobs, which form the design process, and verified the thinking model. The findings suggest that our idea development has the creative process not only of divergent thinking and convergent one, but also of transformation in design. In same time, the design thinking shows their pattern of transition from abstract concept to concrete object. Between the design jobs, idea development shows higher difficulty than other jobs - marketing, product planning and follow-up. Combining the D-T-C (Divergent-Transformation-Convergent) thinking with abstract-concrete thinking, we designed a DFD(data flow diagram) for an early model of computer mediated thinking system (CMTS). This has implications for design support.

• Journal of The Korean Association For Science Education
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• v.31 no.6
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• pp.986-997
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• 2011

In this study, we developed analogical experimental activities to foster scientific creativity in inquiry learning and applied them to 7th grade science-gifted students. The influences of inquiry learning-based analogical experiments were investigated with respect to the experimental design processes. We classified the patterns of experimental design processes by creative thinking processes and analyzed performance levels by the elements of experimental design processes. The students' experimental design processes were categorized into three kinds of patterns such as reinitiated motion, backward-divergent motion and stationary motion. Those belonging to the reinitiated motion performed precise experimental design from new perspectives by identifying the mapping in depth and considering the elements of experimental design processes. In the case of the backward-divergent motion, they shifted their positions to new directions, but the concreteness of experimental design was insufficient due to the lack of mapping or considering the elements. In the type of stationary motion, maintaining their previous positions, they showed less performance of experimental design without considering the elements sufficiently. Educational implication of these findings are discussed.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.1056-1073
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• 2011

The purpose of this study was to develop teaching materials using Pyramid model of divergent thinking, Inverse pyramid model of convergent thinking and Diamond model of divergent-convergent thinking. And the teaching materials was implemented to 120 students in middle school over 10 weeks. Results indicated that the experimental group presented statistically meaningful improvement in creative thinking skills, especially in fluency and flexibility(p<.05). Also the teaching materials contributed to improve critical thinking skills, especially in inquiry process of recognizing problems, making conclusion and generalization(p<.05). Moreover, academic achievement was improved(p<.05). But, there was no significant improvement in creative personality(p<.05).

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.29 no.4
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• pp.178-184
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• 2018

Objectives: The objective of this study was to investigate the concordance of Diagnostic and Statistical Manual of Mental Disorders (DSM-IV and DSM-5) diagnostic criteria for autism spectrum disorder (ASD). Methods: We retrospectively reviewed the medical records of 170 subjects (age range: 3-23, 140 boys) with developmental delay or social deficit from January 2011 to July 2016 at the Department of Psychiatry of Asan Medical Center. The Autism Diagnostic Interview-Revised (ADI-R), the Autism Diagnostic Observation Schedule (ADOS), and intelligence tests were performed for each subject. Diagnosis was reviewed and confirmed for each subject with DSM-IV Pervasive Developmental Disorder (PDD) and DSM-5 ASD criteria, respectively. Results: Fifty-eight of 145 subjects (34.1%) who were previously diagnosed as having PDD in DSM-IV did not meet DSM-5 ASD criteria. Among them, 28 (48.3%) had Asperger's disorder based on DSM-IV. Most algorithm scores on ADOS and all algorithm scores on ADI-R were highest in subjects who met both DSM-IV PDD criteria and DSM-5 ASD criteria (the Convergent group), followed by subjects with a DSM-IV PDD diagnosis who did not have a DSM-5 ASD diagnosis (the Divergent group), and subjects who did not meet either DSM-IV PDD or DSM-5 ASD criteria (the non-PDD group). Intelligence quotient was lower in the Convergent group than in the Divergent group. Conclusion: The results of our study suggest that ASD prevalence estimates could be lower under DSM-5 than DSM-IV diagnostic criteria. Further prospective study on the impact of new DSM-5 ASD diagnoses in Koreans with ASD is needed.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.1
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• pp.18-25
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• 2001

The results of systematic numerical experiments of secondary gas injection thrust vector control are presented. The effects of secondary injection system such as injection location and nozzle divergent cone angle onto the overall performance parameters such as thrust ratio, specific impulse ratio and axial thrust augmentation, are investigated. Complex nozzle exhaust flows induced by the secondary jet penetration is numerically analyzed by solving unsteady three-dimensional Reynolds-averaged Navier-Stokes equations with Baldwin-Lomax turbulence model for closure. Numerical simulations compared with the experiments of secondary air injection into the rocket nozzle of $9.6^{\cire}$ divergent half angle showed good agreement. The results obtained in terms of overall performance parameters showed that locating the secondary injection orifice further downstream of primary nozzle ensures the prevention of occurrence of reflected shock wave, therefore is suitable for efficient and stable thrust vectoring over a wide range of use.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.2
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• pp.94-100
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• 2013

A convergent-divergent nozzle or venturi nozzle has been used to accelerate the wind speed at its throat. The wind speed at the throat is inversely proportional to its area according to the continuity equation. In this numerical study, an airflow phenomena in the venturi system placed at a vertical structure was investigated to understand the vortex effect occurred at the rear-side of the vertical structure on the air speed increment at the throat of the venturi system. For this study, a venturi system sized by $20(m){\times}20(m){\times}6(m)$ was modelled and the area ratio(AR) of the model venturi was 2.86. To see the vortex effect on the air flow acceleration in the venturi throat, two different boundary conditions was defined From the study, it was found that the pressure coefficient(CP) of the venturi system with the vortex formed at the exit of the venturi was about 2.5times of the CP of the venturi system without the vortex effect. The velocity increment rate of the venturi system with the vortex was 61% but 9.5% only at the venturi system without the vortex. Conclusively, it can be said that the venturi system installed in a vertical structure has very positive effect on the flow acceleration at its throat due to the vortex formed at the rear-side of the vertical structure.

• Journal of Korea Water Resources Association
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• v.48 no.2
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• pp.137-147
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• 2015

This study performed the systematic classification of the various types of riffles and analyzed their physical and hydraulic characteristics at the Hongcheon River and Seomjin River. The riffles are classified into the long type and the wide type by their ratio of length and width, and also classified into the convergent type and the divergent type by their width change along flow direction. They are also classified into the falling type, the running type, the undular wave and the undular jump by their surface profiles. The falling type and the running type usually occur near the cobbles with multiple diameters, whereas the undular wave and the undular jump occur near the small pebbles. They showed the upward convex type at the middle part, and the slope gets bigger at the downstream part.