• The Journal of the Acoustical Society of Korea
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• 제25권3E호
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• pp.95-100
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• 2006

The present study presents the design procedures and the acoustic properties of the main hall of Ansan Cultural Arts Center in Korea which has opened in 2004. The acoustic design values are compared with the measured acoustic properties of the completed multi-purpose hall. Acoustic design criteria were suggested in the design stage through the 3-dimentional computer simulations. The acoustic parameters including SPL, RT, C80, $D_{50}$M, RASTI were measured in the hall after completed. Acoustic measurements were carried out in the 40 measurement points using MLS sound source signal in 4 different sound source points. The results show the even distribution of sound levels within the 2.0dB of difference among all seats. The reverberation time of 1.66sec was measured which is similar to the objective value of 1.65 sec in empty states. It was also found that average C80 values lie in the objective extents of C80 from -1 to 3dB and average D50 value of 54 was measured. Thus, it is concluded that the hall can be used as a multi-purpose hall with a suitable acoustic conditions.

• 한국음향학회지
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• 제33권1호
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• pp.40-47
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• 2014

원심팬 날개 깃에서 발생한 와류와 원심팬 볼루트 사이의 상호작용은 원심팬의 주요한 소음원으로 알려져 있다. 본 연구에서는 저소음 설계의 기초 자료로 활용하기 위하여 원심팬의 주요한 소음원 영역으로 고려되는 원심팬 볼루트 영역을 세분화하여 볼루트 영역내의 상대적 기여도를 분석한다. 주요한 소음원으로부터 방사되는 소음을 예측하기 위해 내부 음장용 복합 전산공력음향학(CAA, Computational Aero-Acoustics) 방법을 사용한다. 이 방법은 전산유체역학(CFD, Computational Fluid Dynamics)과 음향상사법(Acoustic Analogy), 그리고 경계요소법(BEM, Boundary Element Method)을 사용하여 원심팬 내부 유동장으로부터 방사한 소음을 원심팬 외부 음향장에서 예측하는 방법이다. 복합 CAA 방법을 이용한 원심팬 볼루트 영역내의 소음원의 상대적 기여도 분석은 컷-오프영역으로부터 출구영역보다 컷-오프영역으로부터 원심팬 스크롤영역이 전체 소음에 대한 기여도가 높고, 날개 깃의 쉬라우드 영역보다 허브 영역이 전체 소음에 대한 기여도가 높다는 것을 보여준다. 이러한 결과는 향후 저소음 원심팬 개발을 위한 유용한 자료로 활용될 것이다.

• 센서학회지
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• 제10권5호
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• pp.320-328
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• 2001

PVDF(Polyvinylidene fluoride) 압전막을 이용하여 $8{\times}8$의 요소를 갖는 2차원 배열 수중청음기를 설계 제작하고. 그것을 이용하여 수 MHz$\sim$수십 MHz 대역의 초음파 음장을 측정하는 방법 및 측정시스템을 구축하였다 수중청음기의 설계에 있어서는 배면체의 종류에 따른 주파수 응답특성을 Mason 등가회로에 의해 해석하였고, 압전체 요소의 크기 및 간격, 스캐닝 스탭에 따른 음장 측정 정도를 검토하였다 2.25MHz의 원형평면 트랜스듀서가 만드는 수중 음장을 제작한 수중청음기 및 측정시스템으로 측정한 결과, 비교적 정밀한 측정이 가능함을 알았다.

• 한국소음진동공학회논문집
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• 제24권2호
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• pp.146-153
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• 2014

This study investigates the effects of seat-design elements such as seating arrangement, shape, and height on speech privacy in high-speed trains. For the evaluation of speech privacy, acoustic simulation software was used to reproduce room acoustical conditions in passenger cars on the basis of in-situ measurement data. The influences of speech source directivity and source height on privacy distance ($r_P$) were investigated, and it was found that $r_P$ determined using an omni-directional source was relatively shorter than that determined using a directional source. It was also found that $r_P$ decreased when the source height was lower than the height of the seat-back because the seat-back blocked the propagation of speech from the sound source. The effect of seating arrangement was not significant when comparing the vis-a-vis seating and one-side seating arrangements. In addition, among the alternative seat-designs, the seats that block the space between the seats and cover the space near the ear were found to show significantly enhanced speech privacy in high-speed train passenger cars.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.696-700
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• 2007

In case of dome-typed gymnastics training floor, since its form takes shape of the focus of sound, in the occasion when the finishing-material was used with the sandwich panel that prominent in reflexibility, and because the reverberation of sound in indoor is too loud, a smooth practice and teaching is very difficult. As this indoor gymnastics training floor, standing at its character, is required simultaneously the idea communication between the player and the coach, and the acoustic capability regarding to the clearness of music, besides the sport activity, the method to minimize the acoustic defect should be urgently contrived from the stages of design and beginning of construction. On this viewpoint, after investigation on the confidence of the surveyed value and the estimated value using acoustic simulation, and use of the changed finish-material, this thesis intends to design the dome-typed gymnastics training floor that secured the optimized acoustic condition. It is also considered that such result of the study could be utilized as the useful data that enables to improve the retrenchment effect of the construction cost as well as the acoustic performance, by means of the prediction control on the acoustic problem from the stage of design, for the occasion when the similar indoor sport gymnasium is planning to build for the near future.

• 한국소음진동공학회논문집
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• 제17권8호
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• pp.708-719
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• 2007

In case of indoor gymnastics training floor, in view of its characteristics, since it is simultaneously required the related smooth communication between the coach and the player, also the acoustic performance regarding to the clearness of music, besides the sport activity, the consideration about the acoustic character has entered the stage as an indispensable element. On such viewpoint, recently constructed dome-typed gymnastic training floor was optimized acoustic design with remodeling through acoustic simulation test. And acoustic satisfaction degree and reaction was attempted to investigate about the gymnastics training floor estimating value of human's psychological(sensual) degree using auralization that enables to experience the virtual sound field at the stage of design. As the result of investigation about the research on the space of object, it could be known that the valuation regarding to the acoustic performance of 'after-improvement' was distinctly more refined than that of 'before-improvement'. It is now considering that such result of the study can be utilized as the useful data which enables to improve the retrenchment effect of the construction cost as well as the acoustic capability, by means of the prediction control on the acoustic problem from the stage of design, for the occasion when the similar indoor sport gymnasium is planning to build for the near future.

• 한국공간구조학회논문집
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• 제7권5호
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• pp.75-82
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• 2007

본 연구는 지붕개폐형 구조물에서 지붕을 개폐함으로써 나타나는 음장의 특성변화를 파악하기 위하여 1/20스케일의 축소모형을 제작하고 이를 대상으로 개폐율을 조절하면서 음장변화를 측정 분석하였다. 공간의 음향설계 시 사용되는 기존의 설계 및 평가파라메타들을 검토한 결과, 잔향음의 감쇠과정이 비선형적이며 기존의 잔향감 평가파라메타인 잔향시간에 의해서 적절한 설계 및 성능평가가 이루어지기 어려울 것으로 분석되었다. 특히 비선형적 감쇠구간에 대한 선형적 curve-fitting에 의해 실제 청감과는 거리가 먼 매우 긴 잔향시간이 도출되어 실질적인 효용성이 의심된다. 따라서 잔향시간(T30)을 음향설계 및 평가과정에서 중요설계변수로 활용 시 완공 후 얻게 되는 음장특성과 상이한 결과를 초래할 가능성이 있다. EDT의 경우 전체적으로 초기감쇠시간은 개폐율이 증가할수록 짧아지는 경향을 나타내었다. 주파수별로 저주파수대역에서의 감쇠율이 가장 높게 나타났으며 고주파수 대역으로 갈수록 감쇠율은 둔화되는 것으로 평가되었다. 명료도 관련 파라메타인 D50 또한 개폐에 따른 음장의 변화를 효과적으로 나타내고 있는 것으로 분석되었다. 객석부위별로는 지붕개폐면에 직접 노출되지 않는 객석에서 개폐율 증가에 따라 선형적인 감쇠현상이 나타나고 있으나, 직접 노출되는 객석의 경우에는 40%이상의 개폐율에서는 명료도와 잔향감에 영향을 거의 미치지 않는 것으로 나타났다.

• 한국실내디자인학회논문집
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• 제19권3호
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• pp.77-85
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• 2010

The Therme Vals is a hotel and spa which combines a complete sensory experience designed by Peter Zumthor. This study aims to find emotional design approaches of the Therme Vals through references, observation from site visit, interview and discussion related to this topic. This space was designed for visitors to luxuriate and rediscover the ancient benefits of bathing. The combinations of light and shade, open and enclosed spaces and linear elements make for a highly sensuous and restorative experience. The study observed the emotional design characteristics of the Therme Vals through space approach, aesthetic and experiential sides. For space approach side, emotional experience in gradual process to approach the space was mentioned, for aesthetic side, mystical combination of light, stone and water was observed, for experiential side, 5 senses experience and space programing for adjusting the density of the space were observed. This study found that the spa has the quality of spiritual, soul-touching delight like religious experience. The fascination for the mystic qualities of a world of stone within the mountain, for darkness and light, for light reflections on the water or in the steam saturated air, pleasure in the unique acoustics of the bubbling water in a world of stone, the ritual of bathing-all these notions were explained in Peter Zumthor's construction details. In the result of the interview and discussion, people love the space and praised it highly for the emotional design regardless of space experience, age, sex or ethnicity. Emotional design approaches based on human nature, materiality, and memory of the places is more powerful than other emotional design ideas with technical devices, special themes, digital effects, vivid colors and shapes.

• 한국전산유체공학회지
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• 제20권2호
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• pp.67-72
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• 2015

In this paper, study of high speed train pantograph arm shape and panhead cross-section for aerodynamic drag and noise reduction is performed. In previous research, it is known that knee of pantograph arm and panhead of pantogpraph are main sources of noise from high speed train pantograph. By numerical simulation using full scale pantograph model, pantograph arm and panhead optimization are performed. As a result, drag and noise are reduced at both studies about high speed pantograph.

• 교육시설
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• 제5권2호
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• pp.16-29
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• 1998

Bell Laboratory introduced the sound and visual system for the first time in 1927. Since then, the development of telecommunication technology made it possible for people located far away to communicate each other watching through the TV screen. Over the period different types of telelecturing systems have prospered in line with the development of telecommunication technology. Therefore, it is quite natural that telelecturing/conferending system attracts the attention of many people as a new way of educating people located in a long distance. In the industrial sector, telelecturing systems already come into wide use to save time and training and travelling expense. In this study, I examine the concept and characteristics of telelecturing/conferencing system and introduce different types telelecturing system developed in parallel with the development of communication technology. Then, I analyze how those merits of the telelecturing system can be applied to educational purpose. Finally, I propose and design ideal telelectuirng/conference facilities consisting of telelecturing rooms, bilateral movie system, seats, ceilings, color, TV screen, lighting, acoustics, humidities and temperature control, security system, projection system to maximize the educational purpose and effectiveness.