• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.1
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• pp.1-8
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• 2017

A new empirical correlation was developed for application to the tandem tubes for saturated water at atmospheric pressure. The correlation was obtained by using experimental data and the least square method to calculate the bundle effect. A statistical analysis was performed to identify the suitability of the correlation. The correlation predicted the experimental data within ${\pm}8%$. The applicable ranges of the correlation correspond to a tube pitch of 28.5~114 mm, an elevation angle of $0^{\circ}{\sim}90^{\circ}$, an inclination angle of $0^{\circ}{\sim}90^{\circ}$, and heat fluxes of $0{\sim}120kW/m^2$ of the lower and upper tubes.

• The Journal of the Acoustical Society of Korea
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• v.20 no.3
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• pp.15-23
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• 2001

This paper presents a voice conversion technique that modifies the utterance of a source speaker as if it were spoken by a target speaker. Feature parameter conversion methods to perform the transformation of vocal tract and prosodic characteristics between the source and target speakers are described. The transformation of vocal tract characteristics is achieved by modifying the LPC cepstral coefficients using Linear Multivariate Regression (LMR). Prosodic transformation is done by changing the average pitch period between speakers, and it is applied to the residual signal using the LP-PSOLA scheme. Experimental results show that transformed speech by LMR and LP-PSOLA synthesis method contains much characteristics of the target speaker.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.2
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• pp.96-103
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• 2020

The new geometric disturbance is proposed to control the flow around the bluff body. The new geometry is characterized by the variable pitch which is applied on the Helically Elliptic Twisted (HET) cylinder. The performance of the HTE geometry as a biomimetic passive flow control was confirmed by Jung and Yoon (2014). The Large Eddy Simulation (LES) is used for the evaluation of the flow control performance of the Variable Pitch HTE (VPHTE) cylinder at Reynolds number (Re) of 3000 corresponding to the subcritical regime. The circular and HTE cylinders are also considered to compare the performance of the VPHTE cylinder at the same Re. The VPHTE cylinder gives the smallest values of the force coefficients than the circular and HTE cylinders. The drag and lift coefficients of the VPHTE cylinder are about 15.2% and 94.0% lower than those of the circular cylinder, respectively. Especially, the VPHTE cylinder achieves about 2.3% and 30.0% reduction of the drag coefficient and the root mean square of the lift coefficient than the HTE cylinder, respectively. Furthermore, The VPHTE cylinder forms more elongated and stabilized separated shear layer than the circular cylinder, which supports the reduction of the force coefficients.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.386-391
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• 2009

In this study, the numerical study has carried out to analyze the factors of the efficiency decrease at backward flow situation in an axial fan with adjustable blades. The analysis is carried out the pitch angle $36^{\circ}$ on the forward flow and the pitch angle $-26^{\circ}$ on the backward flow. The numerical results show that the air flow rates of the pitch angle $36^{\circ}$ and $-26^{\circ}$ are respectively calculated to 285 CMM and 212 CMM. The results are similar to the experimental results carried out by Chang, and have made the maximum error of 10.6% when compared with the experimental results. The important reason of the fan efficiency decrease is that axial fan used for this study was designed to use for the forward flow. As the results, the pitch angle $-26^{\circ}$ has occurred the recirculation around the impeller blade, impeller cover and stator.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.10
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• pp.112-119
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• 2003

Design analysis and grow1d test on propellers for 50 m-long airship propulsion were conducted. The design analysis code developed by adopting the vortex-blade-element theory was applied to the design of optimum propeller at the condition of maximum flight speed at sea level. In order to validate the performance of the propeller, ground test of the propeller was performed, and thrust and torque were measured for several different pitch angles at static condition. The power coefficients and thrust coefficients obtained by the test compared well with the analysis results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.6
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• pp.498-504
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• 2011

The flapping characteristics and advance ratios at torque equilibrium state of autorotation were investigated when the airspeed, shaft angle, and pitch angle were varied. To simulate the airspeed increase, the aerodynamic data analyzed by using the compressible Navier-Stokes solver and Pitt/Peters inflow theory were used. Transient Simulation Method(TSM) was used to catch the torque equilibrium states. The maximum flapping angles at torque equilibrium state were correlated to the airspeed, shaft angle, and pitch angle. By comparing flapping behavior to the variation of advance ratio, the phenomenon that the extension of reverse flow area of retreating blade affects the characteristics of autorotation was qualitatively considered.

• The monthly packaging world
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• s.285
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• pp.82-94
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• 2017

2016년 우수디자인(GD)상품선정 시상식이 지난해 12월 14일코리아디자인센터 컨벤션홀에서 열렸다. '우수디자인(GD)상품선정제도'는 1985년부터 산업디자인진흥법 제6조에 의거하여 상품의 경제성, 사용성, 환경친화성, 심미성 등을 종합적으로 심사하여 디자인이 우수한 상품과 서비스에 GD마크를 부여하는 제도로, 산업통상자원부가 주최하고 한국디자인진흥원이 주관하고 있다. GD마크는 우수한 디자인 상품 개발을 장려하여 국가경쟁력을 확보하고 국민 삶의 질을 향상시키는 것을 목표로 선정하고 있다. 또한 창의 디자인강국 구현을 위해 세계적 인증가치를 구축하고, 유니버설디자인, 서비스디자인, 전통시장 산업단지 디자인을 고도화(우수디자인 선정 장려 등)함으로써 사회적 문제해결과 지속가능한 창조경제 실현에 그 의의가 있다. 올해 선정대상품목은 제품, 커뮤니케이션, 포장, 공간환경, 서비스 등의 부문에서 39개 항목으로 출품됐다. 포장 부문은 소비자제품, 식음료, 뷰티/헬스, 의료, 산업/B2B, 기타 포장 등 6개 항목으로 구성됐다. 올해 포장 부문에서는 플러긴스의 STONE JEJU CANDLE이 국무총리상을, 엘지전자(주)의 LG Sound 360 패키지가 산업통상자원부장관상을, 유씨엘(주)의 아꼬제, (주)퍼스트마켓의 코코스타 핸드모이스쳐 팩, (주)웰코스의 후르디아 크림이 조달청장상을, 일동홀딩스(주)의 그녀는 프로다, 삼성전자(주)의 삼성 모바일 액세서리 패키지 시리즈, 피치앤드의 피치앤드는 KIDP원장상을, (주)유니베라의 남양알로에 맥스피는 중소기업청장상 등을 수상했다. 다음에 우수디자인으로 선정된 포장부문 제품들을 살펴보도록 한다.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.5
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• pp.410-415
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• 2012

An experimental study is carried out to investigate the near-wake characteristics of a NACA 0018 foil with a flat plate. Two-frame grey-level cross correlation PIV method is used to measure the local flow characteristic around a pitch damping foil to control the vertical motion of high speed crafts in a circulating water channel. The analysis also includes angles of attack 10 and 20 degrees respectively. Reynolds number $Re{\fallingdotseq}3.5{\times}10^4$ based on the chord length(C=100mm) of NACA0018 has been applied during the whole experiments. The distance between the foil and the flat plate is D/C=0.5, 1.0 and 1.5 respectively. The channel effect according as the distance between the foil and the flat plate has a close relation with the velocity distributions around the foil. In the wake of 20-degree of attack, the complex turbulent flow and a thick boundary layer are formed due to the processes of vortex generation and dissipation.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.424-427
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• 2017

지금까지 사람들의 말하기 습관을 분석하는 것은 전문가나 다른 사람들의 피드백을 통해 이루어졌다. 이는 평가하는 사람에 따라 다른 결과가 나타날 수 있기 때문에 다소 객관성이 떨어지며 직접 대면이 요구되기 때문에 훈련할 수 있는 시간과 공간에 제약이 있었다. 또 지금까지의 말하기 훈련이라 함은 면접 스피치나 발표 스피치 등 특정 목적을 가지고 진행되었기 때문에 말하기에 있어서의 통합적인 훈련을 받기 어려웠다. 본 연구에서는 가장 기초적인 말하기 습관에 초점을 맞추고 말하기 능력을 '어휘력', '계속성', '발음', '속도'라는 4개의 영역으로 나누어 각 영역을 분석하는 알고리즘을 제시한다. 이 알고리즘을 활용한다면 모두 같은 메커니즘을 통해 분석이 이루어지기 때문에 객관성을 보장할 수 있으며 어플리케이션을 활용해 시간과 공간의 제약을 받지 않고 말하기 습관 개선을 위한 훈련을 할 수 있을 것이다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.4
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• pp.175-180
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• 2014

Experimental investigations of the heat transfer and friction factors in the ribbed divergent rectangular channel with the channel exit hydraulic diameter to inlet hydraulic diameter ratio of 1.16 were performed. The surface heaters were mounted onto the two opposite walls. The main experimental parameter is the ratio of rib pitch (p) to height (e), at which the ratios (p/e) of 6, 10, and 14 are considered in the channel with ribs on one wall only. The straight ribbed square channel is also considered as a comparison. The major findings are that the ratio of p/e = 6 shows the highest values in the heat transfer and the ratio of p/e = 10 indicates the greatest friction factor in the ribbed divergent channel. Editor's note:No major changes or corrections needed. Well written.