• Journal of Photoscience
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• v.3 no.3
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• pp.147-151
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• 1996

Dynamics of contact ion-pair between 1, 2, 4, 5-tetracyanobenzene anion and cation of biphenyl derivatives was investigated on the picosecond time scale. Solvent effect on the electron transfer was observed and electron transfer rates were examined using Marcus equation which contains distance dependence of the electron transfer rate in the frequency factor, along with the consideration of molecular shape. From the discussion based on disk model for molecular shape, contribution of interring torsional motion of biphenyl to the inner-sphere reorganization energy is strongly suggested, which leads to the physical explanation for the observed solvent effect on the rate of electron transfer.

• Journal of The Korean Association For Science Education
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• v.27 no.1
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• pp.28-36
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• 2007

This study investigated the influences of small group discussion and students' visual learning style in learning chemical concepts with drawing and writing as methods to assist students in connecting and integrating multiple external representations. Seventh graders (N=449) at a coed middle school were assigned to individual drawing (ID), pair drawing (PD), individual writing (IW), and pair writing (PW) groups. All students learned "Boyle's Law" and "Charles's Law" for two class periods. Analyses of the results revealed that the students in the PD group, regardless of students' visual learning style, scored significantly higher than those in the ID group in a conception test. The scores of the students with strong visual learning preference in the PW group were significantly higher than those in the IW group in the conception test, while the scores of the students with weak visual learning preference were not significantly different between the two groups. Although the conception test scores of the PD group were higher than those of the PW group, the difference was relatively small. It was found that most students in both PD and PW groups perceived pair drawing and pair writing positively upon cognitive and motivational aspects.

• ETRI Journal
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• v.23 no.1
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• pp.9-15
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• 2001

We suggest a generalized Lax pair on a Hermitian symmetric space to generate a new coupled higher-order nonlinear $Schr{\ddot{o}}dinger$ equation of a dual type which contains both bright and dark soliton equations depending on parameters in the Lax pair. Through the generalized ways of reduction and the scaling transformation for the coupled higher-order nonlinear $Schr{\ddot{o}}dinger$ equation, two integrable types of higher-order dark soliton equations and their extensions to vector equations are newly derived in addition to the corresponding equations of the known higher-order bright solitons. Analytical discussion on a general scalar solution of the higher-order dark soliton equation is then made in detail.

• Korean Journal of Remote Sensing
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• v.17 no.2
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• pp.155-164
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• 2001

In this study, we describe the technique for deriving a digital elevation model (DEM) from a synthetic aperture radar (SAR) stereo image pair and apply it to an image pair over "Kwanak-san" in Seoul, Korea. This paper contains brief discussion of the use of stereo SAR to derive topographic data, description of the overall structure of the stereo SAR processing system, description of the site and SAR data used for the evaluation and the source of validation data, results of the stereo SAR processing, analysis and evaluation of their accuracy against map data, and finally summarizes the main highlights of the method used, comments and recommendations on its future implementation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.1
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• pp.125-132
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• 2002

An experimental study on the characteristics of stability of propane turbulent nonpremixed jet flames discharged normal to air free-streams with uniform velocity profile is conducted. Experimental observations are focused on the flame shape, the stability considering two kinds of flame, lift-off distance, and the flame length according to velocity ratio. In order to investigate the mixing structure of the flame base at the lower limit, we employ the RMS technique and measure the species concentration by a gas chromatography. In the results of the stability curve and lifted flame, it is fecund that the dependency of nozzle diameter is closely related to the large-scale vortical structure representing counter-rotating vortices pair. Also, the detailed discussion on the phenomenon of blowout due to this large vortical motion, is provided.

• Animal cells and systems
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• v.1 no.3
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• pp.429-434
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• 1997

A new genus with a new species of poecilostomatoid copepod, Polyankylis orientalis, is described based on a pair of specimens collected from a tide pool on muddy shore in Korea. It represents a new family of the lichomolgoid complex with the following distinguishing characters: (1) 6-segmented antennule (resulted from the fusion of the third and fourth segments) with additional aesthetascs in male, (2) hook on mediodistal corner of antennal coxobasis (first segment), (3) proximal and distal scales on the outer margin of mandible present, (4) main axis of mandibular gnathobase short and lacking notches at the base of mandibular lash, and (5) inner margin of mandibular lash with denticulate processes. Additionally, maxillar syncoxa carries a large, pointed process on ventral surface, legs 1-4 do not show sexua1 dimorphism, and leg 4 is uniramous with 1-segmented exopod. A detailed discussion is given of its affinities with the ten existing families of the lichomolgoid complex.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.542-545
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• 1995

This paper provides an investigation of torque converter system using ERF (Electro-Rheological Fluid). The torque converter system using ERP is a new concepting device because we can change an apparent viscosity of ERF by adapting an electric field. The device was designed by using the equations which were proposed by Carlson et al. The devices based on ERF generally assume one two possible forms. One is the parallel plate type in which the device elements are facing circular disks separated by a flat layer of ERF, The other is coaxial cylinder or Couette types in which the ERF file the annular apace between a pair of coaxial cylindrical electrode. The discussion on this study is specifically for coaxial cylinder gemetry and experiment results show that the measured torque was rapidly increased with the increase of the eletric field.

• Current Optics and Photonics
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• v.8 no.1
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• pp.105-111
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• 2024

We investigate the effect of photon loss on pair production in a hybrid atom-light system. The loss of light field not only affects the generation of photons, but also prevents the generation of atomic collective excitation, although the atoms are not influenced directly. We propose an unbalanced homodyne detection of the number of atomic collective excitation that overcomes the challenge caused by counting uncertainty in practical measurement. In discussion, we show that the intermode correlations and the number correlation is closely related to the initial input state, while the quadrature correlations are independent of the initial state and always exhibit opposite intermode correlations even in the presence of loss.

• Journal of The Korean Association For Science Education
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• v.34 no.2
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• pp.175-186
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• 2014

This study investigated the influences of pair activity on characteristics of science imaginary pictures drawn by elementary school students and their perceptions of science imaginary drawing. To do this, fourth graders (N=123) from one of the elementary schools were selected and assigned to individual science imaginary drawing (n=61) and paired science imaginary drawing (n=62) groups. The students of each group were administered the questionnaires. The analyses of the results indicated that pair science imaginary drawing was useful in some cognitive aspects (e.g., the understanding of science imaginary drawing, the diversification of topics and times, the generation of scientific ideas, and the elaboration of the pictures) and motivational aspects (e.g., the inducement of interest and intimacy about science, interest about science imaginary drawing, and sociability with friends). However, there were some limitations in positively changing the perceptions of some cognitive aspects (e.g., the acquirement of new scientific knowledge, the remembrance of scientific knowledge, the improvement of the ability to construct scientific logics, and the improvement of scientific imagination) and aesthetic aspects (e.g., the improvement of the abilities to express themes in drawing, paint the picture, and complete the works of art). In addition, the difficulties in imagining, selecting the subject, and expressing could not be overcome; a few disadvantages in the lack of discussion skills were also pointed out.

• The Journal of Information Systems
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• v.21 no.1
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• pp.1-17
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• 2012

Common Method Bias(CMB) may cause the potential inflation of correlations between measures assessed via the same method. The problem of CMB has been well known in behavioral sciences because the survey method with self-reporting is vulnerable to CMB. Thus, the discussion on CMB is still ongoing in the MIS research in US. However, in Korea, the MIS research has never paid attention on the CMB problem. The purpose of this study is to examine the CMB problem in the Korean MIS research. To evaluate the effect of CMB, empirical studies on Technology Acceptance Model(TAM) are selected because (1) TAM is one of the MIS research areas studied intensively, (2) TAM is a theoretical model well supported by the existing empirical studies so that the result of this study would have a great ripple effect when the CMB problem turned out to be serious, (3) CMB is domain-specific. 47 TAM samples (out of 45 studies) from three Korean Journals were selected and the relevant data were collected such as correlation matrixes and the measures of the dependent variable. To find and evaluate the size of CMB, two analytic methods (Marker-Variable Technique and Method-Method Pair Technique) are employed. The result showed that there exists CMB in the Korean studies but the problem is not so serious to distort the empirical testing, compared with that of US studies. However, considering that CMB can contaminate the testing results, Korean MIS researchers should explicitly deal with the problem in designing empirical studies and collecting data.