• Title/Summary/Keyword: Dynamic Experiment

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Development of an Aerodynamic Simulation for Studying Microclimate of Plant Canopy in Greenhouse - (2) Development of CFD Model to Study the Effect of Tomato Plants on Internal Climate of Greenhouse - (공기유동해석을 통한 온실내 식물군 미기상 분석기술 개발 - (2)온실내 대기환경에 미치는 작물의 영향 분석을 위한 CFD 모델개발 -)

  • Lee In-Bok;Yun Nam-Kyu;Boulard Thierry;Roy Jean Claude;Lee Sung-Hyoun;Kim Gyoeng-Won;Hong Se-Woon;Sung Si-Heung
    • Journal of Bio-Environment Control
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    • v.15 no.4
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    • pp.296-305
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    • 2006
  • The heterogeneity of crop transpiration is important to clearly understand the microclimate mechanisms and to efficiently handle the water resource in greenhouses. A computational fluid dynamic program (Fluent CFD version 6.2) was developed to study the internal climate and crop transpiration distributions of greenhouses. Additionally, the global solar radiation model and a crop heat exchange model were programmed together. Those models programmed using $C^{++}$ software were connected to the CFD main module using the user define function (UDF) technology. For the developed CFD validity, a field experiment was conducted at a $17{\times}6 m^2$ plastic-covered mechanically ventilated single-span greenhouse located at Pusan in Korea. The CFD internal distributions of air temperature, relative humidity, and air velocity at 1m height were validated against the experimental results. The CFD computed results were in close agreement with the measured distributions of the air temperature, relative humidity, and air velocity along the greenhouse. The averaged errors of their CFD computed results were 2.2%,2.1%, and 7.7%, respectively.

Estimating Grain Weight and Grain Nitrogen Content with Temperature, Solar Radiation and Growth Traits During Grain-Filling Period in Rice (등숙기 온도 및 일사량과 생육형질을 이용한 벼 종실중 및 종실질소함량 추정)

  • Lee, Chung-Kuen;Kim, Jun-Hwan;Son, Ji-Young;Yoon, Young-Hwan;Seo, Jong-Ho;Kwon, Young-Up;Shin, Jin-Chul;Lee, Byun-Woo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.55 no.4
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    • pp.275-283
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    • 2010
  • This experiment was conducted to construct process models to estimate grain weight (GW) and grain nitrogen content (GN) in rice. A model was developed to describe the dynamic pattern of GW and GN during grain-filling period considering their relationships with temperature, solar radiation and growth traits such as LAI, shoot dry-weight, shoot nitrogen content, grain number during grain filling. Firstly, maximum grain weight (GWmax) and maximum grain nitrogen content (GNmax) equation was formulated in relation to Accumulated effective temperature (AET) ${\times}$ Accumulated radiation (AR) using boundary line analysis. Secondly, GW and GN equation were created by relating the difference between GW and GWmax and the difference between GN and GNmax, respectively, with growth traits. Considering the statistics such as coefficient of determination and relative root mean square of error and number of predictor variables, appropriate models for GW and GN were selected. Model for GW includes GWmax determined by AET ${\times}$ AR, shoot dry weight and grain number per unit land area as predictor variables while model for GN includes GNmax determined by AET ${\times}$ AR, shoot N content and grain number per unit land area. These models could explain the variations of GW and GN caused not only by variations of temperature and solar radiation but also by variations of growth traits due to different sowing date, nitrogen fertilization amount and row spacing with relatively high accuracy.

Oxidative Degradation of PCE/TCE Using $KMnO_4$ in Aqueous Solutions under Steady Flow Conditions (유동조건에서 $KMnO_4$도입에 따른 수용액중 PCE/TCE의 산화분해)

  • Kim, Heon-Ki;Kim, Tae-Yun
    • Economic and Environmental Geology
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    • v.41 no.6
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    • pp.685-693
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    • 2008
  • The rates of oxidative degradation of perchloroethene (PCE) and trichloroethene (TCE) using $KMnO_4$ solution were evaluated under the flow condition using a bench-scale transport experimental setup. Parameters which are considered to affect the reaction rates tested in this study were the contact time (or retention time), and the concentration of oxidizing agent. A glass column packed with coarse sand was used for simulating the aquifer condition. Contact time between reactants was controlled by changing the flow rate of the solution through the column. The inflow concentrations of PCE and TCE were controlled constant within the range of $0.11{\sim}0.21\;mM$ and $1.3{\sim}1.5\;mM$, respectively. And the contact time was $14{\sim}125$ min for PCE and $15{\sim}36$ min for TCE. The $KMnO_4$ concentration was controlled constant during experiment in the range of $0.6{\sim}2.5\;mM$. It was found that the reduction of PCE and TCE concentrations were inversely proportional to the contact time. The exact reaction order for the PCE and TCE degradation reaction could not be determined under the experimental condition used in this study. However, the estimated reaction rate constants assuming pseudo-1st order reaction agree with those reported based on batch studies. TCE degradation rate was proportional to $KMnO_4$ concentration. This was considered to be the result of using high inflow concentrations of reactant, which might be the case at the vicinity of the source zones in aquifer. The results of this study, performed using a dynamic flow system, are expected to provide useful information for designing and implementing a field scale oxidative removal process for PCE/TCE-contaminated sites.

A Study on Audio-Visual Interactive Art interacting with Sound -Focused on 21C Boogie Woogie (사운드에 반응하는 시청각적인 인터랙티브 아트에 관한 연구)

  • Son, Jin-Seok;Yang, Jee-Hyun;Kim, Kyu-Jung
    • Cartoon and Animation Studies
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    • s.35
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    • pp.329-346
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    • 2014
  • Art is the product from the combination of politics, economy, and social and cultural aspects. Recent development of digital media has affected on the expansion of visual expression in art. Digital media allow artists to use sound and physical interaction as well as image as an plastic element for making a work of art. Also, digital media help artists create an interactive, synaesthetic and visual perceptive environment by combining viewers' physical interaction with the reconstruction of image, sound, light, and among other plastic elements. This research was focused on the analysis of the relationship between images in art work and the viewer and data visualization using sound from the perspective of visual perception. This research also aimed to develop an interactive art by visualizing physical data with sound generating from outer stimulus or the viewer. Physical data generating from outer sound can be analyzed in various aspects. For example, Sound data can be analyzed and sampled within pitch, volume, frequency, and etc. This researcher implemented a new form of media art through the visual experiment of LED light triggered by sound frequency generating from viewers' voice or outer physical stimulus. Also, this researcher explored the possibility of various visual image expression generating from the viewer's reaction to illusionary characteristics of light(LED), which can be transformed within external physical data in real time. As the result, this researcher used a motif from Piet Mondrian's Broadway Boogie Woogie in order to implement a visual perceptive interactive work reacting with sound. Mondrian tried to approach at the essence of visual object by eliminating unnecessary representation elements and simplifying them in painting and making them into abstraction consisting of color, vertical and horizontal lines. This researcher utilized Modrian's simplified visual composition as a representation metaphor in oder to transform external sound stimulus into the element of light(LED), and implemented an environment inducing viewers' participation, which is a dynamic composition maximizing a synaesthetic expression, differing from Modrian's static composition.

THE EFFECT OF THE pH OF REMINERALIZED BUFFER SOLUTIONS ON DENTIN REMINERALIZXATION (재광화 완충용액의 pH 변화가 상아질의 재광화에 미치는 영향)

  • Kim, Sung-Chul;Roh, Bung-Duk;Jung, Il-Young;Lee, Chan-Young
    • Restorative Dentistry and Endodontics
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    • v.32 no.2
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    • pp.151-161
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    • 2007
  • Dental caries is the most common disease in the oral cavity However, the mechanism and treatment of dental caries is not completely understood since many complex factors are involved. Especially the effect of pH on remineralization of early stage of dental caries is still controversial In this study, dental caries in dentin was induced by using lactic acidulated buffering solutions and the loss or inorganic substance was measured. Also decalcified specimens were remineralized by three groups of solution with different pH (group of pH 4.3, 5.0, and 5.5). Then, the amount and the area of inorganic substance precipitation was quantitatively analyzed with microradiograph. Also a qualitative comparison of the normal phase the demineralized phase, and the remineralized phase of hydroxyapatite crystal was made under SEM. The results were as follows, 1. In microradiograghic analysis, as the pH increased, the amount of remineralization in decalcified dentin tended to increase significantly As the pH decreaced, deeper decalcification, however, occurred along with remineralization. The group of pH 5.5 had a tendency to be remineralized without demineralization (p<0.05). 2. In SEM view, the remineralization in dentine caries occurred from the hydroxyapatite crystal surface surrounding the mesh of organic matrix, and eventually filled up the demineralized area. 3. 5 days after remineralization, hydroxyapatite crystal grew bigger with deposition of inorganic substance in pH 4.3 and 5.0 group, and the crystal in the remineralized area appeared to return to normal. After 10 days, the crystals in group of pH 4.3 and 5.0, which grew bigger after 5 days of remineralization, turned back to their normal size, but in group of pH 5.5, some crystals were found to double their size. In according to the results of this experiment, the decalcifying and remineralizing process of dentine is neither simple nor independent, but a dynamic process in which decalcification and remineralization occur simultaneously. The remineralization process occurred from the hydroxyapatite crystal surface.

The Effect of Rain on Traffic Flows in Urban Freeway Basic Segments (기상조건에 따른 도시고속도로 교통류변화 분석)

  • 최정순;손봉수;최재성
    • Journal of Korean Society of Transportation
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    • v.17 no.1
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    • pp.29-39
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    • 1999
  • An earlier study of the effect of rain found that the capacity of freeway systems was reduced, but did not address the effects of rain on the nature of traffic flows. Indeed, the substantial variation due to the intensity of adverse weather conditions is entirely rational so that its effects must be considered in freeway facility design. However, all of the data in Highway Capacity Manual(HCM) have come from ideal conditions. The primary objective of this study is to investigate the effect of rain on urban freeway traffic flows in Seoul. To do so, the relations between three key traffic variables(flow rates, speed, occupancy), their threshold values between congested and uncontested traffic flow regimes, and speed distribution were investigated. The traffic data from Olympic Expressway in Seoul were obtained from Imagine Detection System (Autoscope) with 30 seconds and 1 minute time periods. The slope of the regression line relating flow to occupancy in the uncongested regime decreases when it is raining. In essence, this result indicates that the average service flow rate (it may be interpreted as a capacity of freeway) is reduced as weather conditions deteriorate. The reduction is in the range between 10 and 20%, which agrees with the range proposed by 1994 US HCM. It is noteworthy that the service flow rates of inner lanes are relatively higher than those of other lanes. The average speed is also reduced in rainy day, but the flow-speed relationship and the threshold values of speed and occupancy (these are called critical speed and critical occupancy) are not very sensitive to the weather conditions.

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Comparative Assessment of Linear Regression and Machine Learning for Analyzing the Spatial Distribution of Ground-level NO2 Concentrations: A Case Study for Seoul, Korea (서울 지역 지상 NO2 농도 공간 분포 분석을 위한 회귀 모델 및 기계학습 기법 비교)

  • Kang, Eunjin;Yoo, Cheolhee;Shin, Yeji;Cho, Dongjin;Im, Jungho
    • Korean Journal of Remote Sensing
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    • v.37 no.6_1
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    • pp.1739-1756
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    • 2021
  • Atmospheric nitrogen dioxide (NO2) is mainly caused by anthropogenic emissions. It contributes to the formation of secondary pollutants and ozone through chemical reactions, and adversely affects human health. Although ground stations to monitor NO2 concentrations in real time are operated in Korea, they have a limitation that it is difficult to analyze the spatial distribution of NO2 concentrations, especially over the areas with no stations. Therefore, this study conducted a comparative experiment of spatial interpolation of NO2 concentrations based on two linear-regression methods(i.e., multi linear regression (MLR), and regression kriging (RK)), and two machine learning approaches (i.e., random forest (RF), and support vector regression (SVR)) for the year of 2020. Four approaches were compared using leave-one-out-cross validation (LOOCV). The daily LOOCV results showed that MLR, RK, and SVR produced the average daily index of agreement (IOA) of 0.57, which was higher than that of RF (0.50). The average daily normalized root mean square error of RK was 0.9483%, which was slightly lower than those of the other models. MLR, RK and SVR showed similar seasonal distribution patterns, and the dynamic range of the resultant NO2 concentrations from these three models was similar while that from RF was relatively small. The multivariate linear regression approaches are expected to be a promising method for spatial interpolation of ground-level NO2 concentrations and other parameters in urban areas.

Analyzing Inquiry Activities and Exploring the Difficulties of Teaching Inquiry Activities Presented in Science Textbooks for Grades 5-6 (초등 5~6학년 과학 교과서에 제시된 탐구 활동 유형 분석 및 탐구 활동 지도의 어려움 탐색)

  • Chae, Dong-Hyun;Shin, Jung-Yun;Kim, Eun-Ae
    • Journal of the Korean Society of Earth Science Education
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    • v.15 no.2
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    • pp.213-223
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    • 2022
  • The purpose of this study is to identify the types of essential inquiry activities presented in elementary science textbooks for grades 5-6, and to find out what difficulties teachers have in the actual teaching process. To this end, the essential research activities presented in the textbook were analyzed into six types: experimentation/observation, investigation/discussion and presentation, data interpretation, discussion/discussion, simulation activity, and expression. In addition, 108 elementary school teachers were investigated for the suitability of inquiry activity achievement standards, suitability at the student's level, student interest, and difficulty in teaching instruction. To summarize the research results, the most frequently suggested type was the experiment/observation type, followed by simulation activity type and data interpretation type. It was analyzed that there was no discussion/discussion type in the 5th grade textbooks, and the 6th graders did not present research activities that correspond to the research/discussion/presentation type and the expression type in the textbook. In the results of teachers' responses to the suitability of achievement standards for inquiry activities presented in textbooks and the suitability of the student's level, 5th graders showed lower average scores than 6th graders, and showed similar average scores in student interest and instructional difficulty. Also, it was confirmed that improvement was required for a total of 17 inquiry activities. Specifically, teachers responded that they had difficulty in guiding inquiry activities when the experimental results did not appear as intended in the textbook, when students' interest in inquiry activities was low, and when students and teachers had low understanding of related science concepts. Teachers pointed out practical problems such as difficulties in long-term observation in astronomy-related units, and students in upper elementary school not actively participating in dynamic play activities.

Effect of Acute Ethanol Intoxication on the Pulmonary Compliance and Surfactant in Rats (급성(急性) Ethyl 알콜 중독(中毒) 흰쥐의 폐용압률(肺容壓率)과 폐포활성물질(肺胞活性物質)의 변화(變化))

  • Lee, Seung-Jung;Choo, Young-Eun
    • The Korean Journal of Physiology
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    • v.15 no.1
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    • pp.27-36
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    • 1981
  • Relatively little has been done on the metabolic changes of the lung produced by the excessive alcohol ingestion to the point of the acute alcohol intoxication. In the present study, an effort was made to clarify the possible changes of the pulmonary surfactant system by the acute alcohol ingestion. The dynamic pulmonary compliance and the levels of protein and inorganic phosphorus (Pi) of both lung lavage and extract were chosen as the parameters of the pulmonary surfactant activities. The albino rats of both sexes were used, and 1.5 ml of 50% ethanol per 100 g body weight was given by oral intubation, and the experiment was performed at 1, 3, 6, 12, and 24 hours after the alcohol ingestion. The rat was sacrificed by cutting the carotid arteries, and blood sample for the determination of hematocrit(Hct) and the blood alcohol concentration was obtained. Both lungs were completely removed without dammage to the lung tissue, and the pulmonary compliance was measured by the changes of pressure-volume(P-V) curves by inflating or deflating the lung with air. Immediately after the P-V curves were recorded, the lung lavage was obtained by washing the lobes with 15ml of isotonic saline 3 times with a syringe. Next, total lungs were homogenized and filtered to obtain the lung extract. The protein and Pi levels were measured using the lung lavage and extract as the samples, and the lung/body weight ratio(L/B ratio) was also calculated. The results thus obtained were compared with the normal values and summarized as follows. The blood alcohol concentration reached the highest level of $0.71{\pm}0.02\;g\;%$ at 1 hr and gradually decreased until 24 hrs$(0.36{\pm}0.02\;g%)$ after the alcohol ingestion, but all the experimental groups showed significant increase comparing with the normal. The highest Hct value was obtained at 1hr$(64.86{\pm}2.45%)$ and significantly elevated value was continued throughout the experiment. The L/B ratio was significantly lowered from 3hrs until 24hrs after the alcohol ingestion but from 6 th hr on, a generally elevated value was observed with a significant value at 12 hrs and gradual recovery to the normal value at 24 hrs after the alcohol ingestion. The pulmonary compliance at inflation and deflation did not change appreciablly from the normal until 3 hrs after the alcohol ingestion but from 6 th hr on, a generally elevated value was observed with a significant value at 12 hrs and gradual recovery to the normal value at 24 hrs after the alcohol ingestion. The protein level of the lung lavage stowed a significantly increased value of $12.36{\pm}0.35\;mg/gm(3rd hr)$, $12.70{\pm}0.74\;mg/gm(12 th hr)$, and $12.65{\pm}0.88\;mg/gm(24 th hr)$, respectively, comparing with the normal value of $10.65{\pm}0.62\;mg/gm$, and the Pi level also showed a similar tendency of significant increase at 12th hr $(7.65{\pm}0.63\;{\mu}mol/gm)$ and 24 th hr$(6.70{\pm}0.36\;{\mu}mol/gm)$ comparing with the normal value of $5.32{\pm}0.20\;{\mu}mol/gm$. The protein level of the lung extract in the alcohol group was generally similar to the normal value with a slight decrease at 1st and 3 rd hr, tut the Pi level of the lung extract was generally increased in the alcohol group, and a significant increase was observed at 6 th hr$(17.77{\pm}1.54\;{\mu}mol/gm)$, 12 th hr$(13.92{\pm}0.78\;{\mu}mol/gm)$ and 24 th hr$(14.57{\pm}0.53\;{\mu}mol/gm)$ of the alcohol ingestion comparing with the normal value of $10.34{\pm}0.37\;{\mu}mol/gm$. From the above, it may be concluded that the acute alcohol intoxication produces the metabolic changes of the lungs by the increased surfactant activities and elevated pulmonary compliance.

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An Essay on the Change of Jinju Sword Dance after being designated as an Important Intangible Cultural Asset (<진주검무> 중요무형문화재 지정 이후의 변화에 관한 소고)

  • Lee, Jong Sook
    • Korean Journal of Heritage: History & Science
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    • v.49 no.1
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    • pp.4-21
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    • 2016
  • The purpose of this study is to investigate changes of Jinju Sword Dance, characteristics of the changes, and the current condition of its preservation and succession after the designation as the important intangible cultural property no. 12 in January 16th, 1967. In other words, this study understands the situation which has established the present state of after changes over generations. As of now. the year of 2015, the 3 generation holders have been approved since 1967. In 1967, 8 members of $1^{st}$ generation holders were selected from gisaengs of Gwonbeon. However, the succession training was incomplete due to conflicts among the holders, the deaths of some holders, and economic activities of the individuals. As the need of a pivot for succession training and activities was rising, Seong, Gye-Ok was additionally approved as the $2^{nd}$ generation holder on June $21^{st}$, 1978. Seong, Gye-Ok who had never been a gisaeng had dramatically changed with a lot of new attempts. After the death of Seong, Gye-Ok in 2009, Kim, Tae-Yeon and Yu, Yeong-Hee were approved as the $3^{rd}$ generation holders in February, 2010. Based on the resources including the "Cultural Research Reports of Important Intangible Cultural Properties" in 1966 and videos up to 2014, the changes of the dance and surroundings are as follow. 1. The formation of musical accompaniment has been changed during the 3 generations. In the video of the $1^{st}$ generation(in 1970), the performance lasted about 15 minutes, whereas the performance lasted 25 minutes in the video of the $2^{nd}$ generation. Yumbuldoduri rhythm was considered as Ginyumbul(Sangryeongsan) and played more slowly. The original dance requiring only 15 rhythms was extended to 39 rhythms to provide longer performance time. In the $3^{rd}$ generation, the dance recovered 15 rhythms using the term Ginyumbul. The facts that Yumbul was played for 3 minutes in the $1^{st}$ generation but for 5 minutes in the 3rd generation shows that there was tendency pursuing the slowness from the $2^{nd}$ generation. 2. For the composition of the Dance, the performance included additional 20 rhythms of Ginyumbul and Ah(亞)-shaped formation from the $2^{nd}$ generation. From the $3^{rd}$ generation, the performance excluded the formation which had no traditional base. For the movement of the Dance, the bridge poses of Ggakjittegi and Bangsukdoli have been visibly inflexible. Also, the extention of time value in 1 beat led the Dance less vibrant. 3. At the designation as an important intangible cultural property (in 1967), the swords with rotatable necks were used, whereas the dancers had been using the swords with non-rotatable necks since late 1970s when the $2^{nd}$ generation holder began to used them. The swords in the "Research Reports" (in 1966) was pointy and semilunar, whereas the straight swords are being used currently. The use of the straight swords can be confirmed from the videos after 1970. 4. There is no change in wearing Jeonlib, Jeonbok, and Hansam, whereas the arrangement of Saekdong of Hansam was different from the arrangement shown in the "Research Reports". Also, dancers were considered to begin wearing the navy skirts when the swords with non-rotatable necks began to be used. Those results showed that has been actively changed for 50 years after the designation. The $2^{nd}$ generation holder, Seong, Gye-Ok, was the pivot of the changes. However, , which was already designated as an important intangible cultural property, is considered to be only a victim of the change experiment from the project to restore Gyobang culture in Jinju, and it is a priority to conduct studies with historical legitimacy. First of all, the slowing beat should be emphasized as the main fact to reduce both the liveliness and dynamic beauty of the Dance.