• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.6
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• pp.675-682
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• 2010

The flood impact pressure acting on a vertical wall resulting from a dam-breaking problem is simulated using a navier-Stokes(N-S) solver. The N-S solver uses Eulerian Finite Volume Method(FVM) along with Volume Of Fluid(VOF) method for 2-D incompressible free surface flows. A Split Lagrangian Advection(SLA) scheme for VOF method is implemented in this paper. The SLA scheme is developed based on an algorithm of Piecewise Linear Interface Calculation(PLIC). The coupling between the continuity and momentum equations is affected by using a well-known Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) algorithm. Several two-dimensional numerical simulations of the dam-breaking problem are presented to validate the accuracy and demonstrate the capability of the present algorithm. The significance of the time step and grid resolution are also discussed. The computational results are compared with experimental data and with computations by other numerical methods. The results showed a favorable agreement of water impact pressure as well as the global fluid motion.

• Child Health Nursing Research
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• v.18 no.2
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• pp.76-84
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• 2012

Purpose: This study was done to develop a cell phone addiction scale for Korean children. Methods: The process included construction of a conceptual framework, generation of initial items, verification of content validity, selection of secondary items, preliminary study, and extraction of final items. The participants were 268 children from grades 4 to 6 in two urban elementary schools. Construct validity, internal consistence reliability, and split-half reliability were used to analyze the data. Results: Nine items were categorized into 2 factors explaining 61.29% of total variance. The factors were labeled as obsessive compulsion (6 items) and dependency (3 items). Cronbach's alpha coefficient for the 9 items was .87, and Spearman-Brown coefficient was .83. Scale scores identified children as high risk users, at risk users, or average users by standard scores. Conclusion: The above findings indicate that the cell phone addiction scale for children has good validity and reliability when used with Korean children.

• Journal of electromagnetic engineering and science
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• v.17 no.2
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• pp.86-90
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• 2017

In this study, a novel third-order bandpass filter, which is based on a rectangular closed loop resonator, is presented. By adding a series resonator to the conventional loop resonator, the resonator's even resonant mode is split into two modes, while the odd resonant mode is not affected. Therefore, by varying the values of the series resonator elements, the resonant frequencies of two even modes can be determined independent of the odd-mode resonant frequency. In the proposed triple-mode filter design, instead of using a lumped series resonator, a T-shaped transmission line is coupled to the resonator via a small gap. To verify the design method, a filter is designed at 2.4 GHz with a bandwidth of 100 MHz. The improved performances of the proposed triple-mode filter are compared with those of the conventional dual mode filter.

• Korean Journal of English Language and Linguistics
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• v.2 no.1
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• pp.31-52
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• 2002

This paper discusses the nature of the associate NP of English there constructions and attempts to capture the underlying similarity between the associate NP in English and the nominative object in Korean. Specifically, this paper is centered on the Case property of the associate NP. As the first step, previous proposals on the case of the associate NP are critically reviewed. Through the criticism, this paper opposes to Chomsky's (1995, 2000, 2001) analysis and to Lasnik's (1999) partitive Case analysis. In particular, convincing reason for the partitive Case assignment to the associate NP, other than other cases, cannot be found. This paper, therefore, adopts a recent claim of Boeckx (2000) that the Case under consideration is nominative by Agree. His idea is extended to the analysis of the presentational expletive construction. This paper draws a conclusion that the associate NP of the presentational expletive construction has accusative by Agree. This dichotomy (or split) is also observed in the nominative object construction in Korean. In the nominative object construction, the nominative object has nominative Case by Agree, whereas the regular object has accusative by Agree.

• Journal of IKEEE
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• v.24 no.2
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• pp.592-597
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• 2020

Since SiC has 10 times higher breakdown field and 3 times higher energy gap than Si, it is possible to manufacture an excellent power MOSFET with a high breakdown voltage. However, since it has a high on-resistance due to low mobility, a Trench MOSFET has been proposed to lower it, but at the same time, it has a problem that BV decreases. The purpose of this paper is to design a 1200V trench MOSFET, and to solve this, split Epi depth, Trench depth, and Trench depth to Epi depth, which are important variables for BV and Ron, to achieve maximum electric field, BV, Ron's reliability characteristics were compared and analyzed. As the epi depth increased, the trench depth decreased, and the epi depth decreased at the trench depth, the maximum electric field decrease, BV increase, and Ron increase were confirmed. All results were simulated by sentaurus TCAD.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.382-386
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• 2012

A femtosecond laser with 775nm central wavelength and 150 fs of temporal pulse width was used for multi layered glass cutting applications. Ultrashort pulse was effectively used for clean glass cutting with $50{\mu}m$ depth and minimum cutting width. Laser beam was split to two stages and focused on the top surfaces of each layer. Ablation threshold of used glass was measured to be $2.59J/cm^2$. In experiments, 200mW laser power and 1mm/s scanning speed was used for preliminary experiment. Air gap was the major defect occurring parameter and laser power was less sensitive to glass cutting in the experiment. The maximum cutting speed was measured to be 60mm/min with 2kHz, however, Maximum 3m/min cutting speed can be achievable with a commercially available laser with 100kHz.

• Child Health Nursing Research
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• v.21 no.2
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• pp.131-140
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• 2015

Purpose: The purpose of this study was to develop an instrument that evaluated QUality Of care Through patients' Eyes for hospitalized child (QUOTE-Child), and examine the validity and reliability. Methods: Preliminary items were reviewed through expert content validity and face validity. To test the validity and reliability of the instrument, the data were collected from 221 care givers of hospitalized children. Data were analyzed using exploratory factor analysis, Pearson correlation coefficient, Cronbach's alpha and Spearman-Brown coefficient. Results: Factor analysis yielded 19 items in four factors including 1) respect, 2) explanation, 3) kindness, and 4) skillfulness, with a cumulative explanatory variance of 70.68%. For criterion-related validity, a significant positive relationship was found between quality of care and pediatric family satisfaction. For internal consistency reliability, the Cronbach's ${\alpha}$ was .93 (importance) and .95 (performance) for the overall instrument. The half split reliabilities were .86, .95 (importance) and .92, .97 (performance). The Cronbach's ${\alpha}$ of 110 data was .92 (importance) and .94 (performance). Conclusion: Researchers and practitioners can use this instrument to systematically assess quality of care for hospitalized children and identify areas of support for hospitalized children and their family.

• Archives of Reconstructive Microsurgery
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• v.21 no.2
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• pp.111-117
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• 2012

Purpose: To report the clinical results of the perforated-based propeller flap for lower extremity soft tissue reconstruction. Materials and Methods: Between January 2010 and June 2012, a total of 16 defects in the lower extremities were covered with perforator-based propeller flaps. Retrospective data for location and size of the defect, flap dimension, pedicle artery, pedicle rotation, complications were obtained. Results: Peroneal artery-based perforator flap were used in eleven cases, posterior tibial artery-based perforator flap in two cases, anterior tibial artery-based perforator flap in one case and medial plantar artery-based perforator flap in two cases. The average size of the flaps was $63cm^2$. The marginal skin necrosis of the flaps as a complication was developed in two cases, one of which was covered with split-thickness skin graft. There were no functional deficits from the donor site. Conclusion: For the reconstruction of lower extremities, the perforator-based propeller flap could be a reasonable alternative as it is a simple, safe and versatile technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.6C
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• pp.434-441
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• 2005

For LDPC decoding, received symbols are splitted bit by bit based using the received in-phase and quadrature components. The method of bit-splitting is affected on decoding performance because its method depend on distance over symbol constellation. Therefore this paper propose the bit split method using the sector information with sacrifice a little performance loss compared to Euclidean distance method. Futhermore DVB-S2 specification supports BC(Backward Compactible) mode which using the hierarchical modulation method, this paper also analyze the decoding performance according to deviation angle of 8PSK constellation for various LDPC coding rates.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.3
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• pp.337-342
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• 2000

Purpose : The purpose of this study was to analyze the lower third facial changes in frontal view after mandibular setback surgery. Materials and Methods : In this study, fifteen subjects(6 males and 9 females) with class III dental and skeletal malocclusions who were treated with BSSRO(Bilateral Sagittal Split Ramus Ostetomy) were used. Frontal cephalometric radiographs were taken preoperatively and more than 6 months postoperatively, and hard tissue(H2-Hl) and soft tissue changes (S2-S1) were measured on vertical and horizontal reference lines. In 15 cases, changes which developed more than 6 months after surgery were studied. Results : The results were as follows. 1. In the facial height, hard tissue $decreased(2.46{\pm}2.76mm)$ with statistical significance(P<0.01), and soft tissue also $decreased(1.64{\pm}3.66mm)$. As a result, the facial height generally becomes shorter after sagittal split ramus osteotomy. 2. In the mandibular width, hard tissue $decreased(2.08{\pm}3.59mm)$ with statistical sgnificance(P<0.05), but soft tissue $increased (2.14{\pm}5.73mm)$ without statistically significant difference(P>0.05) postoperatively. 3. In the facial index, hard tissue $decreased(0.23{\pm}2.21%)$, but soft tissue $increased(2.41{\pm}3.46%)$ with statistical significance. Conclusion : One of the main purpose of orthognathic surgery is to achieve facial esthetics and harmony. In order to fullfill this purpose, it is important to carry out a precise presurgical treatment planning by estimating the changes of frontal profile after surgery.