• 제목/요약/키워드: Early Reflection

검색결과 156건 처리시간 0.028초

개구부로 연결된 3중 커플룸의 음향특성 (Acoustic Properties of Three-room Coupled System by Connected Two Apertures)

  • 나혜중;임병덕
    • 한국소음진동공학회논문집
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    • 제26권3호
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    • pp.340-349
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    • 2016
  • A coupled room system consists of adjacent rooms and apertures where the sound energy is exchanged between the two rooms. Acoustically, a coupled room system shows a non-exponential decay profile. Most of the related researches have been to analyze the acoustic properties of two-room coupled system so far whereas three-room coupled system were seldom studied. In this regard, this paper aims to analyse the distribution of sound pressure level, sound decay curve of three-room coupled system and sound energy flow between them by using the acoustic diffusion model and to further verify them through experiments. Firstly, the sound pressure level distribution and mean sound pressure level in the steady-state condition are analyzed at various frequencies and source locations. Good agreements are observed in both experiments and analysis results. Secondly, two double slope effect quantifiers of sound attenuation, LDT/EDT and LDT/T10 are compared at various frequencies and for different source locations. The result indicates that LDT/T10, less affected by the early reflection patterns than LDT/EDT, is more suitable to the analysis and experiments of a multi-slope sound decay curve. Lastly, the sound energy flow in each room is analyzed based on the acoustic diffusion model. After the early decay stage, the sound energy is observed to flow from the room with a long reverberation time to the room with a short one.

콘서트홀에서 무대음향에 대한 확산체의 영향 (The Effect of Stage diffusers on the Stage Acoustics in a Concert Hall)

  • 이충화;전진용
    • 한국음향학회지
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    • 제24권3호
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    • pp.171-177
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    • 2005
  • 본 논문에서는 콘서트홀에서 확산체의 Early Stage Support (ST1)에 대한 영향을 알아보기 위하여 1:25 축소모형에서 8지점을 설정하여 ST1을 측정하였다. 무대 바닥에 의한 영향을 살펴보기 위하여 흡음천의 유무에 따라 ST1의 결과값의 차이를 살펴보았다. 무대측벽에 대한 영향을 살펴보기 위하여 기존의 확산체, 확산체를 제거한 경우와 반구 확산체의 3가지 형태의 확산체를 사용하여 측벽의 변화에 의한 ST1 값의 결과를 살펴보았다. 결과적으로 무대 바닥에서의 흡음천의 사용은 ST1에서 고주파의 저감을 일으켰으나 평균값에는 큰 차이가 없었으며, 3가지 형태의 확산체는 뚜렷한 차이를 보이지 않았으나 측정 지점에 따라 ST1 값의 차이가 발생하였고, 특히 반구 확산체에서는 ST1 값이 고르게 분포하였다. 따라서 무대 바닥은 상대적으로 ST1의 변화에 큰 영향을 주지 않았고, 무대 측벽의 형상은 확산현상에 의해 ST1의 분포에 영향을 주었다.

이찬 시의 낭만성과 비극성 (The Romance and Tragedy in Lee Chan's Poetry)

  • 유성호
    • 비교문화연구
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    • 제19권
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    • pp.127-147
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    • 2010
  • Lee Chan's early poems were defined as the world of romance. His second-term poems were defined as proletarian poetry and poems written in prison when he made the romance as the core point through longing and desire for lost world. Maximizing the romance was proletarian poetry. His third-term poems were feelings of the northern countries called the spirit of Lee Chan's poems. He recognized the emotion of diaspora as the tragedy in these poems. It was remarkable time that the poet's tragedy observing and expressing the reality of colony. Afterward he wrote poems related inside withdrawal and war cooperation, finally he wrote poem after defecting to North Korea. Lee Chan showed the romance of desire in early poems and proletarian poems. Then he indicated acute scenery of the tragedy in the late 1930s' poems. In heavy situation, he moved from pro-Japanese literature to North Korean literature. However he didn't throw introspected self-reflection language to himself each his changing. But through several form of garden, he clearly showed consistent of maximizing his utopia sense. The time Lee Chan experienced was an icon which intensively indicated several features of deformed modern Korean poetic history. He was a unique poet who expressed various traces of modern Korean poetry in short time step by step. His path informed that he was a special poet who stepped the trace of many modern Korean poetry's extremes such as romantic poetry, proletarian poetry, prison poetry, pro-Japanese poetry and North Korean poetry. Likewise we can call his life as a grudge return. Because he left hometown, experienced the light and darkness of modern times and returned his hometown.

투겐타트 주택의 공간적 특성에 관한 연구 (A Study on the Spatial Characteristics in the Tugendhat House)

  • 양재혁;견진현
    • 한국실내디자인학회논문집
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    • 제40호
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    • pp.42-51
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    • 2003
  • This study aimed at understanding the spatial characteristics in the Tugendhat house. For this study, it is need to analyze the early plans of the Tugendhat house design process. To analyze this, the study leads to how to effect on the real practice with the process. Therefore, this research investigates the conceptional design process of the house. There are 2 main characteristics of the interior space alternation. One is the closed spatial character on the 2nd floor, the other is the open spatial character on the 1st floor. It clearly shows the severance between interior and exterior on the 2nd floor. Each 2nd floor's space volume uses different materials so that each the space can show the individuality. On the 1st floor, however, it seems the interior is not as much open to the exterior, because the materiality and reflection of the glass, the objet of furniture and wall. In case of 1st floor, it has a complex concept as open and close character, because it is using the proper gardening elements and the relationship between the house and site. The exterior characteristic is separated the house from the ground with the podium and the slope, and this leads to have the discontinuity. The house clearly shows the spatial characteristics of the continuity and discontinuity, it proves that Mies tried to move onto modem architecture as a turning point.

전통의 현대적 계승을 위한 한국 전통건축의 이론화에 대한 비판적 고찰 (A Critical Study on Theorization of Tradition in Korean Architecture)

  • 이상헌
    • 건축역사연구
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    • 제24권6호
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    • pp.35-44
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    • 2015
  • The purpose of this study is to critically investigate the ways in which scholars and architects in Korea have theorised the tradition in Korean architecture from the early 20th century to the present. After opening the door to foreign powers, the most important issue to be resolved in Korea architecture has been the modernization of the traditional architecture. The successful modernization of Korean traditional architecture depends on successful theorization of the tradition. However, many attempts to theorise the uniqueness of tradition in Korean architecture had not been instrumental to the modernization of Korean traditional architecture. The reason why they were not successful lies in the lack of philosophical and methodological reflection upon how to approach the tradition. They were either trapped in ambiguous essentialism without systematic methods and theories, or simply inventing the tradition from the vantage point of the present. This paper argues that in order to theorise the tradition, one need to translate the tradition into contemporary architectural vocabularies. What is important in translating the tradition is not to directly apply contemporary concepts and perceptual frame of architecture to traditional architecture but to find the gaps and differences between the two. This will open hermeneutic spaces to translate the tradition into useful principles and vocabularies of comtemporary architecture.

제르멜로와 공리적 방법 (Zermelo and the Axiomatic Method)

  • 박우석
    • 논리연구
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    • 제11권2호
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    • pp.1-56
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    • 2008
  • 본 논문은 제르멜로가 집합론을 공리화함에 있어서 힐버트의 공리적 방법을 차용하였다는 널리 무비판적으로 받아들여져 온 가정 자체를 검토하고자 한다. 그들이 공유했다고 가정되는 공리적 방법의 실체가 무엇이고 그것은 과연 어느 시기에 정립된 것인지를 묻는 데서 출발해서 공리적 방법에 관한 제르멜로와 힐버트의 사상이 어떻게 상호작용하며 발전해 나갔는지를 철학적 반성을 통해 규명하려는 것이다. 그 결과 후기 사상에서뿐만 아니라 심지어 전기 사상에 있어서도 제르멜로가 집합론 자체와 공리적 방법에 관하여 힐버트와 상당히 다른 견해를 지녔을 가능성을 확인할 것이다. 이러한 결과는 집합론의 역사와 공리적 방법의 역사, 그리고 나아가서 수학철학 전반에 걸쳐 상당한 함축을 지닐 수밖에 없다고 본다.

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미세 간질중첩증에서의 역설적 편측화 (Paradoxical Lateralization of Convulsive Movements in a Subtle Status Epilepticus)

  • 손은희;정기영;김재문
    • Annals of Clinical Neurophysiology
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    • 제4권2호
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    • pp.137-139
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    • 2002
  • Background : Subtle status epilepticus (SE) is an end-stage of convulsive SE. This phenomenon might be a clinical expression of neuronal exhaustion caused by sustained electrical discharges. As subtle SE may show diverse clinical features, early detection depends on clinical suspicion. Case : A 68-year-old woman was presented with repetitive involuntary movement of right limbs after two generalized tonic-clonic seizures. She experienced right middle cerebral artery infarction 4 months ago, and after the event, left side hemiplegia sustained. These seizures were first-ever after the cerebral infarction. Orientation and verbal responses were fairly preserved but general cognitive function was minimally slowed. During the video-EEG monitoring, repetitive sharp waves were noted in the right hemisphere and these sharp waves occasionally spread to the contralateral side. Her right side involuntary movement was identifiable when the epileptic discharges were found on her right hemisphere. Conclusion : We suggested that this unexpected convulsive movement is a reflection of earlier exhaustion in the right hemisphere or deefferentation of right hemisphere because of preexisting neuronal damage.

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LPCVD 공정중 웨이퍼의 온도장 해석 (Thermal analysis of the wafers in LPCVD process)

  • 김일경;정민철;유승일;채승기;김우승;남기흠
    • 대한기계학회논문집B
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    • 제22권5호
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    • pp.651-660
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    • 1998
  • In the LPCVD reactor the temperature variations within the wafer load are the most important factor to maintain the thickness of the materials deposited on the surface of the wafer constant and to affect the deformation of each wafer. In this study the temporal variations of radial and axial temperature nonuniformities of each wafer in the LPCVD reactor are numerically estimated by assuming diffuse reflection. To verify the validity of the present numerical results, the present results obtained from the transient analysis are compared with those of Badgwell's work in which a steady-state condition was assumed. The main objective of this work is to determine the temporal variations of the temperature of each wafer in the LPCVD process since the wafers experience severe change in temperature in the early stage of the process.

급격한 광도 변화가 담배 잎에서 반사되는 Normalized Difference Vegetation Index에 미치는 영향 (Effect of a Sudden Increase in Light Intensity on Normalized Difference Vegetation Index (NDVI) Reflected from Leaves of Tobacco)

  • 서계홍
    • 한국환경과학회지
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    • 제26권4호
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    • pp.543-547
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    • 2017
  • Normalized Difference Vegetation Index (NDVI) has played an important role in assessing green plant biomass through remote sensing on global scale since the early 1970s. The concept of NDVI is based on the fact that green plants show higher reflection in near-infrared region than in visible region of the electromagnetic spectrum. However, it is well known that the relocation of chloroplasts in plant leaf cells may dramatically change the optical properties of plant leaves. In this study I traced the changes in the reflectance and transmittance properties of Tobacco leaves at the wavelengths of 660 and 800 nm after a sudden increase in light intensity. The results showed that NDVI of leaves gradually decreased from 72.7% to 69.9% when exposed to a sudden increase in light intensity from 30 to $1,200{\mu}mol/m^2{\cdot}s$. This means that the error resulting from the physiological status of the plant should be accounted for a more precise understanding of ground truth corresponding to the data from the remotely acquired images.

잔류응력 영역에서 발생한 작은 피로균열의 초음파 평가 (Ultrasonic evaluation of small surface fatigue cracks initiating in residual stress zone)

  • 강계명;김진연
    • 한국가스학회지
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    • 제4권1호
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    • pp.55-62
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    • 2000
  • Pit형 표면결함으로부터 발생하는 작은 피로균열의 거동을 초음파의 표면파를 이용하여 이를 위하여 피로시험중인 Al 2024-T3를 시험재료, 피로시험도중 초음파를 이용하여 피로균열의 거동을 조사하였다. 즉, 피로시험에서 균열이나 Pit로부터 발생하는 작은 피로균열을 여러 응력조건하에서 나타나는 표면파의 반사특성에 관하여 연구하였다. 또한 이론적 결과와 실험적 결과를 상호 비교, 분석하였고, SEM을 사용하여 이들 작은 피로균열을 관찰하였다. 초음파를 이용한 피로균열의 균열 개구 거동에 관한 연구에서 피로균열의 유효균열 특성을 초음파법으로 평가 할 수 있었다.

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