• 음성과학
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• 제8권4호
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• pp.87-98
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• 2001

Vocal nodule is one of the representative chronic diseases of vocal folds, and it can be cured by surgical removal or voice therapy. The aim of this study is to evaluate the effect of the accent method, one of the popular effective voice therapy, in the patients with vocal nodule. Authors executed the accent method in 17 patients with vocal nodule who visited the Voice & Speech Therapy Clinic, Pusan National University Hospital analysed the voice before and after treatment using the local findings, acoustic analysis and aerodynamic analysis MPT. The voice was analysed with MDVP of CSL and MPT was checked using stop watch. The parameters included Fo, Jitter, Shimmer and noise to harmonic ratio(NHR) as acoustic analysis. The results were obtained as follows. In the evaluation by the local findings, it was improved to 77% in the patients of vocal nodule. Jitter and Shimmer were shown to be improved significantly. In particular, it was shown to be improved significantly in patients with vocal nodule. As the result of this study, the improvement of aerodynamic aspect was more statistically significant than that of acoustic parameters. When I generalized the above mentioned results, we suggest that it is a useful voice therapy which can be helpful to the improvement of voice, applying the accent method to the vocal nodule patients, and there are currently many methods to be used in the voice therapy, but it is thought which the accent method is the good treatment as the alternatives of keeping the continuous medical treatment.

• 설비공학논문집
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• 제25권5호
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• pp.279-288
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• 2013

Heat transfer and pressure drop characteristics of fin-and-tube heat exchangers having sine wave fins and oval tubes were investigated. Oval tubes having an aspect ratio of 0.6 were made, by deforming 12.7 mm round tubes. Twelve samples, having different fin pitch and tube row, were tested. The effect of fin pitch on the j and f factors was negligible. The effect of the tube row on the j factor, however, was different from that of common fin-and-tube heat exchangers having plain fins and round tubes. The highest j factor was obtained for a two-row configuration, while the lowest one was obtained for a one-row configuration. A possible reason was attributed to the flow mixing characteristics of the sine wave channel of the present geometry. Comparison with a plain fin-and-tube heat exchanger having 15.88 mm O. D. round tube reveals that the present oval fin-and-tube heat exchanger shows generally superior thermal performance, except for the one-row configuration.

• Structural Engineering and Mechanics
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• 제78권2호
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• pp.117-124
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• 2021

This work focused on the novel numerical tool for the bending responses of carbon nanotube reinforced composites (CNTRC) beams. The higher order shear deformation beam theory (HSDT) is used to determine strain-displacement relationships. A new exponential function was introduced into the carbon nanotube (CNT) volume fraction equation to show the effect of the CNT distribution on the CNTRC beams through displacements and stresses. To determine the mechanical properties of CNTRCs, the rule of the mixture was employed by assuming that the single-walled carbon nanotubes (SWCNTs)are aligned and distributed in the matrix. The governing equations were derived by Hamilton's principle, and the mathematical models presented in this work are numerically provided to verify the accuracy of the present theory. The effects of aspect ratio (l/d), CNT volume fraction (Vcnt), and the order of exponent (n) on the displacement and stresses are presented and discussed in detail. Based on the analytical results. It turns out that the increase of the exponent degree (n) makes the X-beam stiffer and the exponential CNTs distribution plays an indispensable role to improve the mechanical properties of the CNTRC beams.

• Earthquakes and Structures
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• 제23권2호
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• pp.151-168
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• 2022

Torsion is one of the most important causes of building collapse during earthquakes. Sometimes, despite the symmetric form of the building, infill walls disturb the symmetry of the lateral resisting system. The purpose of this research is to investigate the effect of urban layout on developing torsion caused by infill walls. For this purpose, a typological study was conducted based on the conditions of perimeter walls on 364 buildings and then 9 cases were selected. The dimensions of the selected buildings are constant and the conditions of the perimeter walls including facades with openings and cantilevered facades are variable. The selected buildings with 60 different layouts of infill walls were analyzed and the behavior of each one was evaluated based on the torsional irregularity criteria of seismic codes. The results of the analyses showed that if the perimeter walls of a building are symmetric, asymmetric interior walls will not be important in developing torsion and effective parameters in symmetry of the perimeter infill walls are the number of walls, area of openings, aspect ratio, and construction details. Finally, architectural solutions to mitigate the torsional effects of infill walls were proposed for buildings with solid infill walls on some sides, for buildings where the perimeter walls of one side are on the cantilevered part, and for buildings where the perimeter walls of two adjacent sides are on the cantilevered part. In three-sided buildings, where two adjacent façades are cantilevered, it is often impossible to use the potential of the infill walls.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3775-3786
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• 2023

Mixing Vane Grid (MVG) is one of the most important structures in fuel assembly due to its high performance in mixing the coolant and ultimately increasing Critical Heat Flux (CHF), which avoids the temperature rising suddenly of fuel rods. To evaluate the mixing performance of the MVG, a Total Diffusion Coefficient (TDC) mixing coefficient is defined in the subchannel analysis code. Conventionally, the TDC of the spacer grid is obtained from the combination of experiments and subchannel analysis. However, the processing of obtaining and determine a reasonable TDC is much challenging, it is affected by boundary conditions and MVG geometries. In is difficult to perform all the large and costing rod bundle tests. In this paper, the CFD method was applied in TDC analysis. A typical 5 × 5 MVG was simulated and validated to estimate the mixing performance of the MVG. The subchannel code was used to calculate the TDC. Firstly, the CFD method was validated from the aspect of pressure drop and lateral temperature distribution in the subchannels. Then the effect of boundary conditions including the inlet temperature, inlet velocities, heat flux ratio between hot and cold rods and the arrangement of hot and cold rods on MVG mixing and TDC were studied. The geometric effects on mixing are also carried out in this paper. The effect of vane pattern on mixing was investigated to determine which one is the best to represent the grid's mixing performance.

• Structural Engineering and Mechanics
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• 제89권6호
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• pp.557-570
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• 2024

Due to interfacial ageing, chemical action and interfacial damage, the interface debonding may appear in the interfaces of composite laminates. Particularly, the laminates display a side-dependent effect at small scale. In this work, a three-dimensional (3D) and anisotropic thick nanoplate model is proposed to investigate the effects of imperfect interface and nonlocal parameter on the bending deformation, vibrational response and buckling stability of one-dimensional (1D) hexagonal quasicrystal (QC) layered nanoplates. By combining the linear spring model with the transferring matrix method, exact solutions of phonon and phason displacements, phonon and phason stresses of bending deformation, the natural frequencies of vibration and the critical buckling loads of 1D hexagonal QC layered nanoplates are derived with imperfect interfaces and nonlocal effects. Numerical examples are illustrated to demonstrate the effects of the imperfect interface parameter, aspect ratio, thickness, nonlocal parameter, and stacking sequence on the bending deformation, the vibrational response and the critical buckling load of 1D hexagonal QC layered nanoplate. The results indicate that both the interface debonding and nonlocal effect can reduce the stiffness and stability of layered nanoplates. Increasing thickness of QC coatings can enhance the stability of sandwich nanoplates with the perfect interfaces, while it can reduce first and then enhance the stability of sandwich nanoplates with the imperfect interfaces. The biaxial compression easily results in an instability of the QC layered nanoplates compared to uniaxial compression. QC material is suitable for surface layers in layered structures. The mechanical behavior of QC layered nanoplates can be optimized by imposing imperfect interfaces and controlling the stacking sequence artificially. The present solutions are helpful for the various numerical methods, thin nanoplate theories and the optimal design of QC nano-composites in engineering practice with interfacial debonding.

• 한국자기학회지
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• 제1권2호
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• pp.60-68
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• 1991

급속냉각기술로 제조된 $Nd_{14}Fe_{76}Co_{4}B_{6}$ 및 $Nd_{10.5}Fe_{79}Co_{2}Zr_{15}B_{7}$ 자성분말을 사용하여 성형체와 본드자석을 제조하였다. 자기특성, 최적충진률 등의 분말입도 및 형상비에 따른 거동은 합금조성에 따라 달리 나타난다. Co/Fe 비가 작은 저밀도의 $Nd_{10.5}Fe_{79}Co_{2}Zr_{1.5}B_{7}$ 합금이 같은 성형압력에서 성형체의 성형밀도 및 최적충진률이 높아 자기특성이 우수하였으나 반면에 분말입도에 따라 자기특성이 변화하였다. 성형밀도(p)와 성형압력(P) 사이 에는 ${\phi}(g/cm^{2})=5.2~5.6{\times}P^{0.045~0.065}(ton/cm^{2})$의 관계식이 성립된다. 높은 Nd/Fe 비를 갖는 급속냉각된 $Nd_{14}Fe_{76}Co_{4}B_{6}$ 합금의 초미세립(50~60 nm)으로써 높은 보자력($iH_{c}=14~15kOe$)을 보유하나, Nd/Fe비가 낮은 $Nd_{10.5}Fe_{79}Co_{2}Zr_{1.5}B_{7}$ 합금은 결정립이 조대하고(150~400 nm)Nd-rich한 입경계상의 발달이 부진하여 자벽고착기구가 주 보자력 기구 로 판명된 두 합금에서 고착지점으로서의 역할이 불충분하여 보자력이 낮은 것으로 판명되었다.

• 한국콘텐츠학회논문지
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• 제18권1호
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• pp.196-209
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• 2018

은행의 수익성과 관련하여 어떠한 요인들이 영향을 미치는지 연구하고 있다. 본 연구에서는 은행의 수익성 개선을 위한 자금조달구조의 다양화 측면에서 기존연구와 달리 시장성수신비중을 주요 관심변수로 하여 8개의 설명변수와 총자산영업이익률을 수익성 지표로 사용하여 가설설정하고 전체기간과 금융위기 전 후 로 비교 분석하여 차이를 보고자 한다. 다중회귀분석한 결과, 모든 분석기간에서 유의미한 결과가 나타나는 수익성 요인은 원화예대금리차, 점포수, 고정이하여신비율이며 국내은행은 원화예대금리차가 커지고 점포수가 증가할수록 수익성도 향상되고 부실여신이 증가하면 수익성도 하락하는 것을 알 수 있다. 시장성수신비중은 은행의 수익성에 통계적으로 유의미한 영향을 주지는 못하는 것으로 나타났다. 글로벌 금융위기이전에는 거시경제지표의 영향을 받기 보다는 개별 은행의 상황 및 다른 금융환경의 영향을 더 받았다는 것을 알 수 있으며 금융위기이후에는 은행의 여신이 증가하면서 수익성도 향상되는 것으로 추정할 수 있다. 은행의 수익성 요인은 분석 기간별 특징이 있다고 추론되며 이에 그 의미와 시사점을 가진다. 향후 은행산업의 수익성에 관한 연구는 특수은행이 포함된 국내은행 전체로 대상을 확대할 필요가 있다.

• 대한가정학회지
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• 제34권4호
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• pp.249-263
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• 1996

According to the design method for constructing the G gori(the traditional Korean jacket)collar, there are differences in form after its completion. In the construction design of the midsection of the gusset as in that of the basic G gori, not only was the positioning of the two sides of the collar not smooth, but also, when the collar strip was attached, there would be an imbalance on one side or the other so that it was difficult to achieve symetry. Therefore in this project, by applying the pattern design of the gusset midsection to that of the collar midsection, not only did attaching the collar and the collar strip create a visual effect by equalizing the lengths of the tow sides, but the construction was also easy. This method of construction introduces the three-dimensional aspect of the human form in its conic, spherical and cylindrical aspects, so that, through schematizing the scientific character of Korea's clothing, its appropriateness is verified. As a matter of fact, since th-ere in no standardization of pattern whether for educational use or for mass-produced clothing, so that even the patterns used in computer-assisted design are executed according to the designer's personal skill, the reality is that after completion of construction the quality has not been uniform. For this schematization, inverse calculation of measurements pertaining to the calculation formula and of teaching materials has been referenced. In particular, the partial requlation of the calculation formula pertaining to the basic pattern construction, the method of making the collar midsection, and the construction method of the extreme and mean ratio adjustment can be adjusted for all measurements, thereby providing the establishment of a design criterion and the possibility of the standardization of construction methods. The production method for the pattern design is as follows: 1) The conic angle for the G gori's girth, length and neck width is fixed at 70 degrees. 2) The radius of the cone is B/2. 3) The calculation formula is B/4 + 1.5cm 4) The armhole formula is B/4, the same as in the basic method. 5) The width formula is B/10. 6) The ratio of the collar junction(width of collar + width of collar strip)to the gusset length is 5:8. 7) The length of the side seam is a length intersecting the armhole line and the conic radius (B/2), that is an arc that exceeds the length of the G gori's midsection; the component ratio of this length to the collar junction is accordingly 13:5. 8) The curve frame length of the back midsection is an arc exceeding B/4(the armhole line). 9) The ratio of the sleeve opening calculation formula to the armhole length is 8:5, forming an arc with the midsection length.

• 만화애니메이션 연구
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• 통권28호
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• pp.125-153
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• 2012

본고는 무빙이미지에서 모션의 양태성 전략이 매체나 장르에 어떤 변화를 가져오는지에 관한 연구이다. 오늘날 모션의 양태성은 애니메이션 뿐만 아니라 영화에서도 적극적으로 조작되는 요소이다. 여기서 모션의 양태성 전략은 일반적으로 장르나 매체에 따라 좌우된다고 말해지는데, 과연 그 명제는 옳은 것인가? 옳다면, 본 명제를 학제적으로 규정되어 있지 않은 '장르 매체'라는 용어를 재고함으로써 좀 더 이론적으로 정리할 수는 없는가? 본고는 그러한 문제를 논의하고자 한다. 본고는 모션의 양태성 조작을 이론적 지평 위에서 바라본다. 맥루한의 핫/쿨미디어 이론과 볼터의 진동이론에서 보면, 궁극적으로 모션 양태성 조작의 효과는 수용자의 감각비율 조작과 같은 것으로 귀결되는데, 이러한 이론적 추론은 사례를 통해 검증될 것이다. 사례 분석에서 본 연구자는 이미지의 모션 양태성 조작이 텍스트 내에서 어떤 효과들을 발현하는 지를 분석하고, 이 효과들이 매체 장르 포지셔닝과 어떤 상관성을 갖는 지를 살펴봄으로써, 본고가 문제시 하는 모션 양태성의 장르 매체 결정론을 평가한다. 결론적으로, 모션의 양태성은 매체의 문제와는 상관없이 장르의 문제에서 결정되는 전략인데, 그 장르는 감각자극의 배합으로 포지셔닝되는 범주라고 할 수 있다. 그렇기 때문에 모션의 양태성 전략은 단위 시퀀스가 필요로 하는 감각성에 좌우된다. 모션의 양태성은 단순히 모션캡처 같이 매체적 측면에서 갖는 기술지향적, 경제적 가치보다 장르적 측면에서 기능성으로 접근해야 하는 전략이다.