• The Journal of Korean Academic Society of Nursing Education
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• v.21 no.3
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• pp.320-329
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• 2015

Purpose: The purpose of this study was to identify the relationship among hesitation factor of questions, critical thinking disposition, and problem solving. Methods: Data were collected from 370 students at a university in D city using a structured questionnaire from April 1 to April 15, 2015. It was analyzed with frequency analysis, descriptive statistics, t-tests, ANOVA, and correlation analysis. Results: Subjects scored an average of $2.62{\pm}.52$ for hesitation factor of questions, $3.53{\pm}0.42$ for critical thinking disposition, and $3.44{\pm}0.44$ for problem solving. There were significant differences in the three variables according to satisfaction with major, self-expression, and interpersonal relationships. In addition, hesitation factor of questions exhibited a significant difference between genders. Hesitation factor of questions had a negative relationship with critical thinking disposition (r=-.23, p<.001) and with problem solving (r=-.34, p<.001). In addition, there was a statistically significant positive correlation between critical thinking disposition and problem solving (r=.69, p<.001). Conclusion: In order to improve critical thinking disposition and problem solving, we need to generate a lot of questions to the student's inside. We also need to develop appropriate teaching methods so that this can be expressed by the actual question coming from the control hesitation factor of questions.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.845-854
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• 2004

Motif databases are used in the function and structure prediction of proteins. The frequency of use about these databases increases continuously because of protein sequence data growth. Recently, many researches about motif resource integration are proceeding. However, existing motif databases were developed independently, thus these databases have a heterogeneous search result problem. Database intnegration for this problem resolution has a periodic update problem, a complex query process problem, a duplicate database entry handling problem and BML support problem. Therefore, in this paper, we suppose a database resource integration method for these problem resolution, describe periodically integrated database update method and XML transformation. finally, we estimate the implementation of our prototype and a case database.

• 전자공학회논문지 IE
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• v.45 no.1
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• pp.24-30
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• 2008

In this paper, Digital MultiTone(DMT) is an emerging multi-carrier modulation scheme, which has been adopted for VDSL(Very high speed Digital Subscribe Line). A problem of DMT is its sensitivity to frequency offset between the transmitted and received carrier frequencies. This frequency offset introduces inter-carrier interference(ICI) in the DMT symbol. This paper is proposed an ICI cancelation scheme using Kalman Filtering. The performance of the proposed method is compared with conventional methods in terms of bit error rate performance, bandwidth efficiency, and computational complexity. Through simulations, it is shown that for high values of the frequency offset and for higher order modulation schemes, the EKF(Enhanced Kalman Filtering) method perform better than the others.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.5 s.347
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• pp.104-112
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• 2006

In this thesis, we analyze performance related to reduction scheme of intercell interference causing serious problems in wiBro system. Frequency reusing factor(FUF) is 1 in WiBro system, and it means that a adjacent cell uses same frequency band. This channel environment raises intercell interference problem, which provokes serious problems related to system performance and channel capacity. Consequently, it affects deterioration in system performance as a whole. We analyze intercell interference when appling a various schemes such as (DCA)Dynamic Channel Allocation, CS(Channel Segregation), IMUFR(Interference Mitigation Using Frequency Reuse), IDMA(Interleave Division Multiple Access), IDMA(Interleave Division Multiple Access), FH-OFDM, CRSA(Conceptual Random Subcarrier Allocation), and HDD

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.14-14
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• 2009

High frequency electromagnetic(EM) waves are increasingly being applied in industries because of saturationat lower frequency bands as a result of huge demand. However, electromagneticinterference (EMI) has become a serious problem, and as a result, highfrequency EM absorbers are now being extensively studied. Also, recentdevelopments in absorber technology have focused on producing absorbers thatare thin, flexible, and strong. Hence, one-dimension ferrous nano-materials area potential research field, because of their interesting electronic andmagnetic properties. Commercially, EM wave absorbing products are made ofcomposites, which blend the insulating polymer with magnetic fillers. Inparticular, the shape of the magnetic fillers, such flaky, acicular, or fibrousmagnetic metal particles, rather than spherical, is essential for synthesizingthin and lightweight EM wave absorbers with higher permeability. High aspectratio materials exhibit a higher permeability value and therefore betterabsorption of the EM wave, because of electromagnetic anisotropy. Nanowires areusually fabricated by drawing, template synthesis, phase separation, selfassembly, and electrospinning with a thermal treatment and reduction process.Producing nanowires by the electrospinning method involves a conventionalsol-gel process that is simple, unique, and cost-effective. In thispresentation, Magnetic nanowire and dielectric materials coated magneticnanowire with a high aspect ratio were successfully synthesized by theelectrospinning process with heat treatment and reduction. In addition toestimating the EM wave absorption ability of the synthesized magnetic anddielectric materials coated magnetic nanowire with a network analyzer, weinvestigated the possibility of using these nanowires as high-frequency EM waveabsorbers. Furthermore, a wide variety of topics will be discussed such as thetransparent conducting nanowire and semiconducting nanowire/tube with theelectrospinning process.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.1
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• pp.34-39
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• 2002

Most X-ray generator had been used do rectifier type transformer high tension generator which is supplied in a clinical diagnosis. But it is difficult to miniaturize and become light weight. Also, because the ripple rate of tube voltage is high, X-ray generating efficiency is very low. Therefore, it is supplied gradually from abroad being developed high tension generator for inverter type X-ray generator which use semi-conductor switching element for electric power that have high speed switching ability to solved these problem. But, semi-conductor element of big capacity are used by X-ray tube's big consumption power and diffusion is difficult in the small size hospital because production cost is ascending by doing digital control through DSP and product price becomes expensive. Therefore, in this paper, design and manufactured CR type voltage divider for feedback control of tube voltage of high frequency resonance type inverter and high tension transformer for high frequency to apply economical diffusion type X-ray generator which have wide output voltage and load extent. It is Proved do X-ray generator and stability of X-ray tube's output characteristics through an experiment.

• Journal of Korean Elementary Science Education
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• v.17 no.2
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• pp.55-65
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• 1998

This study was intended to suggest the desirable direction in the 7th national curriculum revision through the analysis of the elementary science textbooks in the 6th national curriculum. The analysis system was composed of three categories, (1)knowledge (2)inquiry process and (3)attitude. And knowledge was divided into fact, concept and rule. And inquiry process was divided into thirteen subcategories such as manipulating experimental apparatus, observing, measuring, recording data, classifying, interpreting/ predicting, determining relationship/ causal explanation, extrapolating/ interpolating, drawing conclusions/ formulating a generalization or model, evaluating, formulating a problem, generating a hypothesis and designing an experiment/ controlling variables. Each sentence in the textbooks was considered as an analyzing unit. The frequency and percentage of each category were counted and the ratios were calculated. The findings could be summarized as follows: 1. The content of the elementary science textbooks was composed of knowledge 10.3%, inquiry process 88.8%, attitude 0.8% respectively. 2. As increasing the grades, the ratio of knowledge showed high frequency, but that of attitude showed low frequency. 3. In All the grades, the ratio of observing was the highest in inquiry process. 4. In the domain of physics and chemistry, the manipulating experimental apparatus showed high frequency. In the domain of biology and earth science, the role of observing was emphasized.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.107-111
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• 2013

The gyroscopes have been used as a suitable inertial instrument for the navigation guidance and attitude controls. The accuracy as very sensitive sensor is limited by the lock-in region (dead band) due to the frequency coupling between two counter-propagating waves at low rotation rates. This frequency coupling gives no phase difference, and an angular increment is not detected. This problem can be overcome by mechanically dithering the gyroscope. This paper presents the design method of mechanical dither by the theoretical considerations and the verification of the theoretical equations through FEM applications. As a result, comparing to the past result, the maximum prediction error of resonant frequency was within 3 percent and peak dither rate was within 5 percent. It was found that the theoretical equations can be feasible for the mechanical performance of dither.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.447-449
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• 2004

The purpose of this study is measured surface acoustic wave(SAW) characteristics to confirm utilization possibility as SAW sensor using new Pb(Mg$_{1}$3/Nb$_{2}$3/) $O_3$-PbTiO$_3$ (PMN-PT) piezoelectric substrate. We have tried to see if the material can be practically available as a new surface acoustic wave (SAW) biosensor to detect protein. The experimental results clarified that the frequency filtering of the central frequency of the PMN-PT substrate is a superior result to that of the LiTaO$_3$ (LT) substrate, but the result was not completely satisfactory. We know there is a problem in the design of inter-digital transducer (IDT) pattern. The waves transferred through the input terminal forms SAW which is sure to be transferred to the direction of the output terminal and the backward direction of the input terminal. This reflected wave is reiterated with SAW, which is transferred to the output direction, and so the frequency filtering gives a not good result. The electromechanical coupling coefficient of the PMN-PT substrate is excellent, and we can use it as a SAW sensor, in the near future, provided that there will be a new IDT design to increase the frequency filtering.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.9
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• pp.8-13
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• 2014

Currently it is major problem of electric railway with increasing drive speed such as the arc generated by the pantograph detachment and the distortion current in the motor-block high speed switching. When physical contact between the pantograph and the catenary line is separated, the pantograph detachment arcing occurs and it makes up the conductive noise to the return feeder. We made the EMTP modeling of the railway traction system and the pantograph arc by circuit elements and switches. The influence of pantograph detachment frequency is investigated by changing some frequencies. The over-current occurs in each detachment and it oscillates some time at beginning and stabilizes gradually. The magnitude of over-current is decided by instantaneous value of existing traction return current. If the detachment occurs at a point of peak value or distortion current, the over-current will be more harmful to the power systems connected with the return feeder and will become to arise with increasing detachment frequency.