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Long-term Variation and Flux of Organic Carbon in the Human-disturbed Yeongsan River, Korea (영산강의 유기물 플럭스와 장기변동에 대한 연구)

  • CHO, HYEONG-CHAN;CHO, YEONG-GIL
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.22 no.4
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    • pp.187-198
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    • 2017
  • Dissolved and particulate organic carbon concentrations and fluxes were measured and estimated for the Yeongsan River during 2006~2015. The dissolved organic carbon (DOC) concentrations ranged from 2.49 to $4.39mg{\cdot}C/L$ with a variance of 30.1% (${\sigma}_x/\bar{x}$), and showed a simple correlation to algal bloom and precipitation. The particulate organic carbon (POC) concentrations had gradually decreased from 6.68 to $0.19mg{\cdot}C/L$ for 10 years, and changed definitely with weir construction in 2011. Based on the relationships between POC and suspended particulate matters and between POC and chlorophyll-a, we found out that the distinct variation of the origin and composition of POC was caused by stagnation and screening effect of the dammed river. The total organic carbon (TOC) concentrations dropped to 52.3% (from 8.26 to $3.94mg{\cdot}C/L$) as the POC concentrations diminished to more than 94.8% after weir construction, in which the DOC forms up to 90.9%. The fluxes of TOC, based on the relationship between the annual TOC concentration and the discharge of Yeongsan dike sluice, were $2.56{\sim}19.41{\times}10^9g{\cdot}C/yr$, and showed a great deal of variability in 2011. Since then the TOC flux dropped to $5.40{\times}10^9$ (2011~2015) from $14.54{\times}10^9g{\cdot}C/yr$ (2006~2010). These results suggest that the weirs trapped annually $1.83{\times}10^9g{\cdot}C$ on a river bed, but released in great levels of dissolved organic form at their exits.

The intrinsic instabilities of fluid flow occured in the melt of Czochralski crystal growth system

  • Yi, Kyung-Woo;Koichi Kakimoto;Minoru Eguchi;Taketoshi Hibiya
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1996.06a
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    • pp.179-200
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    • 1996
  • The intrinsic instabilities of fluid flow occurred in the melt of the Czochralski crystal growth system Czochralski method, asymmetric flow patterns and temperature profiles in the melt have been studied by many researchers. The idea that the non-symmetric structure of the growing equipment is responsible for the asymmetric profiles is usually accepted at the first time. However further researches revealed that some intrinsic instabilities not related to the non-symmetric equipment structure in the melt could also appear. Ristorcelli had pointed out that there are many possible causes of instabilities in the melt. The instabilities appears because of the coupling effects of fluid flow and temperature profiles in the melt. Among the instabilities, the B nard type instabilities with no or low crucible rotation rates are analyzed by the visualizing experiments using X-ray radiography and the 3-D numerical simulation in this study. The velocity profiles in the Silicon melt at different crucible rotation rates were measured using X-ray radiography method using tungsten tracers in the melt. The results showed that there exits two types of fluid flow mode. One is axisymmetric flow, the other is asymmetric flow. In the axisymmetric flow, the trajectory of the tracers show torus pattern. However, more exact measurement of the axisymmetrc case shows that this flow field has small non-axisymmetric components of the velocity. When fluid flow is asymmetric, the tracers show random motion from the fixed view point. On the other hand, when the observer rotates to the same velocity of the crucible, the trajectory of the tracer show a rotating motion, the center of the motion is not same the center of the melt. The temperature of a point in the melt were measured using thermocouples with different rotating rates. Measured temperatures oscillated. Such kind of oscillations are also measured by the other researchers. The behavior of temperature oscillations were quite different between at low rotations and at high rotations. Above experimental results means that the fluid flow and temperature profiles in the melt is not symmetric, and then the mode of the asymmetric is changed when rotation rates are changed. To compare with these experimental results, the fluid flow and temperature profiles at no rotation and 8 rpm of crucible rotation rates on the same size of crucible is calculated using a 3-dimensional numerical simulation. A finite different method is adopted for this simulation. 50×30×30 grids are used. The numerical simulation also showed that the velocity and flow profiles are changed when rotation rates change. Futhermore, the flow patterns and temperature profiles of both cases are not axisymmetric even though axisymmetric boundary conditions are used. Several cells appear at no rotation. The cells are formed by the unstable vertical temperature profiles (upper region is colder than lower part) beneath the free surface of the melt. When the temperature profile is combined with density difference (Rayleigh-B nard instability) or surface tension difference (Marangoni-B nard instability) on temperature, cell structures are naturally formed. Both sources of instabilities are coupled to the cell structures in the melt of the Czochralski process. With high rotation rates, the shape of the fluid field is changed to another type of asymmetric profile. Because of the velocity profile, isothermal lines on the plane vertical to the centerline change to elliptic. When the velocity profiles are plotted at the rotating view point, two vortices appear at the both sides of centerline. These vortices seem to be the main reason of the tracer behavior shown in the asymmetric velocity experiment. This profile is quite similar to the profiles created by the baroclinic instability on the rotating annulus. The temperature profiles obtained from the numerical calculations and Fourier transforms of it are quite similar to the results of the experiment. bove esults intend that at least two types of intrinsic instabilities can occur in the melt of Czochralski growing systems. Because the instabilities cause temperature fluctuations in the melt and near the crystal-melt interface, some defects may be generated by them. When the crucible size becomes large, the intensity of the instabilities should increase. Therefore, to produce large single crystals with good quality, the behavior of the intrinsic instabilities in the melt as well as the effects of the instabilities on the defects in the ingot should be studied. As one of the cause of the defects in the large diameter Silicon single crystal grown by the

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Estimation of Groundwater Recharge by Considering Runoff Process and Groundwater Level Variation in Watershed (유역 유출과정과 지하수위 변동을 고려한 분포형 지하수 함양량 산정방안)

  • Chung, Il-Moon;Kim, Nam-Won;Lee, Jeong-Woo
    • Journal of Soil and Groundwater Environment
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    • v.12 no.5
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    • pp.19-32
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    • 2007
  • In Korea, there have been various methods of estimating groundwater recharge which generally can be subdivided into three types: baseflow separation method by means of groundwater recession curve, water budget analysis based on lumped conceptual model in watershed, and water table fluctuation method (WTF) by using the data from groundwater monitoring wells. However, groundwater recharge rate shows the spatial-temporal variability due to climatic condition, land use and hydrogeological heterogeneity, so these methods have various limits to deal with these characteristics. To overcome these limitations, we present a new method of estimating recharge based on water balance components from the SWAT-MODFLOW which is an integrated surface-ground water model. Groundwater levels in the interest area close to the stream have dynamics similar to stream flow, whereas levels further upslope respond to precipitation with a delay. As these behaviours are related to the physical process of recharge, it is needed to account for the time delay in aquifer recharge once the water exits the soil profile to represent these features. In SWAT, a single linear reservoir storage module with an exponential decay weighting function is used to compute the recharge from soil to aquifer on a given day. However, this module has some limitations expressing recharge variation when the delay time is too long and transient recharge trend does not match to the groundwater table time series, the multi-reservoir storage routing module which represents more realistic time delay through vadose zone is newly suggested in this study. In this module, the parameter related to the delay time should be optimized by checking the correlation between simulated recharge and observed groundwater levels. The final step of this procedure is to compare simulated groundwater table with observed one as well as to compare simulated watershed runoff with observed one. This method is applied to Mihocheon watershed in Korea for the purpose of testing the procedure of proper estimation of spatio-temporal groundwater recharge distribution. As the newly suggested method of estimating recharge has the advantages of effectiveness of watershed model as well as the accuracy of WTF method, the estimated daily recharge rate would be an advanced quantity reflecting the heterogeneity of hydrogeology, climatic condition, land use as well as physical behaviour of water in soil layers and aquifers.

Production of Transgenic Pigs with an Introduced Missense Mutation of the Bone Morphogenetic Protein Receptor Type IB Gene Related to Prolificacy

  • Zhao, Xueyan;Yang, Qiang;Zhao, Kewei;Jiang, Chao;Ren, Dongren;Xu, Pan;He, Xiaofang;Liao, Rongrong;Jiang, Kai;Ma, Junwu;Xiao, Shijun;Ren, Jun;Xing, Yuyun
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.7
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    • pp.925-937
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    • 2016
  • In the last few decades, transgenic animal technology has witnessed an increasingly wide application in animal breeding. Reproductive traits are economically important to the pig industry. It has been shown that the bone morphogenetic protein receptor type IB (BMPR1B) A746G polymorphism is responsible for the fertility in sheep. However, this causal mutation exits exclusively in sheep and goat. In this study, we attempted to create transgenic pigs by introducing this mutation with the aim to improve reproductive traits in pigs. We successfully constructed a vector containing porcine BMPR1B coding sequence (CDS) with the mutant G allele of A746G mutation. In total, we obtained 24 cloned male piglets using handmade cloning (HMC) technique, and 12 individuals survived till maturation. A set of polymerase chain reactions indicated that 11 of 12 matured boars were transgene-positive individuals, and that the transgenic vector was most likely disrupted during cloning. Of 11 positive pigs, one (No. 11) lost a part of the terminator region but had the intact promoter and the CDS regions. cDNA sequencing showed that the introduced allele (746G) was expressed in multiple tissues of transgene-positive offspring of No.11. Western blot analysis revealed that BMPR1B protein expression in multiple tissues of transgene-positive $F_1$ piglets was 0.5 to 2-fold higher than that in the transgene-negative siblings. The No. 11 boar showed normal litter size performance as normal pigs from the same breed. Transgene-positive $F_1$ boars produced by No. 11 had higher semen volume, sperm concentration and total sperm per ejaculate than the negative siblings, although the differences did not reached statistical significance. Transgene-positive $F_1$ sows had similar litter size performance to the negative siblings, and more data are needed to adequately assess the litter size performance. In conclusion, we obtained 24 cloned transgenic pigs with the modified porcine BMPR1B CDS using HMC. cDNA sequencing and western blot indicated that the exogenous BMPR1B CDS was successfully expressed in host pigs. The transgenic pigs showed normal litter size performance. However, no significant differences in litter size were found between transgene-positive and negative sows. Our study provides new insight into producing cloned transgenic livestock related to reproductive traits.

Selectively Partial Encryption of Images in Wavelet Domain (웨이블릿 영역에서의 선택적 부분 영상 암호화)

  • ;Dujit Dey
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.6C
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    • pp.648-658
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    • 2003
  • As the usage of image/video contents increase, a security problem for the payed image data or the ones requiring confidentiality is raised. This paper proposed an image encryption methodology to hide the image information. The target data of it is the result from quantization in wavelet domain. This method encrypts only part of the image data rather than the whole data of the original image, in which three types of data selection methodologies were involved. First, by using the fact that the wavelet transform decomposes the original image into frequency sub-bands, only some of the frequency sub-bands were included in encryption to make the resulting image unrecognizable. In the data to represent each pixel, only MSBs were taken for encryption. Finally, pixels to be encrypted in a specific sub-band were selected randomly by using LFSR(Linear Feedback Shift Register). Part of the key for encryption was used for the seed value of LFSR and in selecting the parallel output bits of the LFSR for random selection so that the strength of encryption algorithm increased. The experiments have been performed with the proposed methods implemented in software for about 500 images, from which the result showed that only about 1/1000 amount of data to the original image can obtain the encryption effect not to recognize the original image. Consequently, we are sure that the proposed are efficient image encryption methods to acquire the high encryption effect with small amount of encryption. Also, in this paper, several encryption scheme according to the selection of the sub-bands and the number of bits from LFSR outputs for pixel selection have been proposed, and it has been shown that there exits a relation of trade-off between the execution time and the effect of the encryption. It means that the proposed methods can be selectively used according to the application areas. Also, because the proposed methods are performed in the application layer, they are expected to be a good solution for the end-to-end security problem, which is appearing as one of the important problems in the networks with both wired and wireless sections.

호스피스와 종교적 죽음이해

  • Sin, Min-Seon;Kim, Mun-Su
    • Korean Journal of Hospice Care
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    • v.6 no.1
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    • pp.1-11
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    • 2006
  • There are various understandings how to define death. In the context of medicine, death is defined as the irreversible change of the tissue according to the cessation of circulation and respiration. According to the psychologists, a person need to accept the finiteness as a human being and remain conscious that the death is not avoidable. And they say if a person doesn't regard death as unavoidable reality of life he or she will not confront the humanistic death and after all will die like animals. In philosophy, death is viewed as an unwelcome reality in the end of the journey of life. Sociologists usually understand that the society is the organization composed with living persons and human beings which construct and transmit the culture from generation to generation between the both ends of life and death. In society, the generation is changed, maintained, and developed through the phenomenon of death. Although death of human being is natural event in society, the death of a specific person brings a sense of loss, crisis, and anxiety to the communities like family, regional society, nation, and the world. In this context, death is not confined to personal dimension and it can be regarded as a social problem. It is valuable to summarize the religious perspectives on the meaning of death for the better hospice care. In shamanism, there are basic idea that although the flesh of human being disappears, soul never die. If human dies, the flesh of human being disappears but soul never disappear and come back to the origin of soul as it is called chaos. So in shamanism, it is said that shaman can solve the mortified feeling, restore the broken harmony, send the soul to comfortable space- the origin, and guarantee the blessing of descendents. Buddhists regard the death as an essential component through the cycles of life. Through this cycle, human being exits as an endlessly transmigrating being and the death is just a restoration to the original status. In Confucianism, the view on the death based on the philosophy of the "Yin and Yang" and "Five elements". In Buddhist tradition, many believers said the philosophy of "Death is the same as life". Unlike usual thoughts that a god governs "life and death" and "fortune and misfortune", Confucianists deny the governance of a god and emphasize the natural orders in which every phenomenon in the world moves according to the principle. Confucianists understand the death as a natural order with this principle. In Confucianists' belief, the essence of human being remains in their own descendent's lives after the death of ancestor, so in Confucianism there is no concept of immortality of the soul. In the history of Christianity, death has been defined generally as the separation of the immortal soul from the mortal body. In the earlier days of Old Testament, the death is regarded as a disappearance of just a flesh and human never disappear and always live in the relationship with God. Later days in Old Testament, we can find the growing concern for the life after the death because of the entrance of the theodicy. In the New Testament, the death is not regarded as the normal process of the human life and regarded as the abnormal status in which death come to human because of sin as a decisive factor and it should be conquered. In fact, the most of us afraid death because not of the fear of death itself but of the sense of the emptiness and regrets. so many people often make the monument hoping to live forever. But Christian usually regard this behavior as a sinful act because human being usually think themselves as a master of their life and attempt to become immortal in this kind of trial mortal. But if we live with God, we cannot confront such a condition because we aware limits as a mortal human being and entrust everything on Him and want to live according to His guidance. Therefore, in the Christian tradition, the death is regarded as accomplishment of life, fruits of life, invitation to the eternal life, and the last stage of human growth. For human being, the death is the great step of maturation as a human in the final stage of life.

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A hybrid algorithm for the synthesis of computer-generated holograms

  • Nguyen The Anh;An Jun Won;Choe Jae Gwang;Kim Nam
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.07a
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    • pp.60-61
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    • 2003
  • A new approach to reduce the computation time of genetic algorithm (GA) for making binary phase holograms is described. Synthesized holograms having diffraction efficiency of 75.8% and uniformity of 5.8% are proven in computer simulation and experimentally demonstrated. Recently, computer-generated holograms (CGHs) having high diffraction efficiency and flexibility of design have been widely developed in many applications such as optical information processing, optical computing, optical interconnection, etc. Among proposed optimization methods, GA has become popular due to its capability of reaching nearly global. However, there exits a drawback to consider when we use the genetic algorithm. It is the large amount of computation time to construct desired holograms. One of the major reasons that the GA' s operation may be time intensive results from the expense of computing the cost function that must Fourier transform the parameters encoded on the hologram into the fitness value. In trying to remedy this drawback, Artificial Neural Network (ANN) has been put forward, allowing CGHs to be created easily and quickly (1), but the quality of reconstructed images is not high enough to use in applications of high preciseness. For that, we are in attempt to find a new approach of combiningthe good properties and performance of both the GA and ANN to make CGHs of high diffraction efficiency in a short time. The optimization of CGH using the genetic algorithm is merely a process of iteration, including selection, crossover, and mutation operators [2]. It is worth noting that the evaluation of the cost function with the aim of selecting better holograms plays an important role in the implementation of the GA. However, this evaluation process wastes much time for Fourier transforming the encoded parameters on the hologram into the value to be solved. Depending on the speed of computer, this process can even last up to ten minutes. It will be more effective if instead of merely generating random holograms in the initial process, a set of approximately desired holograms is employed. By doing so, the initial population will contain less trial holograms equivalent to the reduction of the computation time of GA's. Accordingly, a hybrid algorithm that utilizes a trained neural network to initiate the GA's procedure is proposed. Consequently, the initial population contains less random holograms and is compensated by approximately desired holograms. Figure 1 is the flowchart of the hybrid algorithm in comparison with the classical GA. The procedure of synthesizing a hologram on computer is divided into two steps. First the simulation of holograms based on ANN method [1] to acquire approximately desired holograms is carried. With a teaching data set of 9 characters obtained from the classical GA, the number of layer is 3, the number of hidden node is 100, learning rate is 0.3, and momentum is 0.5, the artificial neural network trained enables us to attain the approximately desired holograms, which are fairly good agreement with what we suggested in the theory. The second step, effect of several parameters on the operation of the hybrid algorithm is investigated. In principle, the operation of the hybrid algorithm and GA are the same except the modification of the initial step. Hence, the verified results in Ref [2] of the parameters such as the probability of crossover and mutation, the tournament size, and the crossover block size are remained unchanged, beside of the reduced population size. The reconstructed image of 76.4% diffraction efficiency and 5.4% uniformity is achieved when the population size is 30, the iteration number is 2000, the probability of crossover is 0.75, and the probability of mutation is 0.001. A comparison between the hybrid algorithm and GA in term of diffraction efficiency and computation time is also evaluated as shown in Fig. 2. With a 66.7% reduction in computation time and a 2% increase in diffraction efficiency compared to the GA method, the hybrid algorithm demonstrates its efficient performance. In the optical experiment, the phase holograms were displayed on a programmable phase modulator (model XGA). Figures 3 are pictures of diffracted patterns of the letter "0" from the holograms generated using the hybrid algorithm. Diffraction efficiency of 75.8% and uniformity of 5.8% are measured. We see that the simulation and experiment results are fairly good agreement with each other. In this paper, Genetic Algorithm and Neural Network have been successfully combined in designing CGHs. This method gives a significant reduction in computation time compared to the GA method while still allowing holograms of high diffraction efficiency and uniformity to be achieved. This work was supported by No.mOl-2001-000-00324-0 (2002)) from the Korea Science & Engineering Foundation.

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The post-epic characteristics in Jan Lauwers' theatre -, and - (얀 라우어스(Jan Lauwers) 공연의 탈서사적 특징들 -<이사벨라의 방(Isabella's Room)>, <랍스터 가게(The Lobster Shop)>, <사슴의 집(Deer House)>을 중심으로-)

  • Nam, Jisoo
    • Journal of Korean Theatre Studies Association
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    • no.48
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    • pp.447-484
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    • 2012
  • This study aims to analyze the characteristics of post-epic theatre in the Belgian theatre director Jan Lauwers' trilogy titled in "Happy Face/Sad Face": (2004), (2006) and (2008). I regard that it played a very important junction for him to create his own theatrical style compared to earlier years. From this period, Lauwers has tried to create his original plays in order to concentrate the story of our era and has showed to combine a variety of media such as dance, installation, video, singing etc. In this context, I would like to study his own theatricality from the three perspectives of dramaturgy, directing and acting largely based on Hans-Thies Lehmann's theory of post-epic theatre, who pointed out the significance of Lauwer's theatrical leading role very early. First, from the dramaturgical point of view, we need to pay attention to the theme of translunary death; where the living and the dead coexist on the stage. In fact, death is the theme that Lauwers has been struggling to research for quite long time. In his trilogy, the dead never exits the stage. The dead, who is not a representative tragic character, even meddles the things among or with the living and provide comments to people. As a consequence, it happens to reduce a dramaturgical strong tension, leads depreciation of suspense and produces humanism in a way. This approach helps to create his unique comical theatrical atmosphere even though he deals with the contemporary tragic issues such as war, horror and death. Second, from the directing point of view, it is worth to take a look at the polyphonic strategy in terms to applying various media. Among all the things, the arts of dancing and singing in chorus are actively applied in Lauwer's trilogy. The dance is used in individual and microscopic way, on the other hand, singing shows collective and is a macroscopic quality. The dance is the representing media to show Lauwer's simultaneous microscopic mise-en-scene. While main plot takes place around the center-stage, actors perform a dance around the off-centered stage. Instead of exiting from the stage during the performance, the actors would continue dance -sometimes more like movements- around the off-centered stage. This not only describes the narrative, but also shows how each character is engaged to the main plot or incident, and how they look into it as a character. Its simultaneous microscopic mise-en-scene intends to function such as: showing a variety moments of lives, amplifying some moments or incidents, revealing character's emotion, creating illusionary theatrical atmosphere and so on. Meanwhile, singing simple lyrics and tunes are an example of the media to stimulate the audiences' catharsis. As the simple melody lingers in the audiences' mind, it ends up delivering a theatrical message or theme after the performance. This message would be transferred from the singing in chorus functions as a sort of leitmotive in order to make an impression to the audience. This not only richens their emotion but also creates an illusionary effect. Third, from the acting perspective, I'd like to point out the "detachment" aesthetic which Lehmann has pointed out. The actors never go deep into the drama by consistently doing recognize a theatrical illusion. The audience happens to pay attention to their presence through the actor's deliberate gesture, business, movement, rhythm, language, dance etc. The actors are against forming closed action by speaking in various languages or by revealing deliberately stage directions or acts, and by creating expressive mise-en-scene with multiple media. As a consequent, the stage can be transformed to not a metaphoric but a metonymic place. These actions are the ultimate intention for a direct effect to the audience. So to speak, Lauwers uses the anti-illusionary theatrical method: the scenes of fantastic death, interruption of singing and dance, speaking many kinds of languages, acting in detachment-status and so on. These strategies function to make cracks in spectators' desire who has a desire to construct a linear narrative. I'd like to say that it is the numerous potentiality to let the reality penetrate though and collide the reality with a fiction. By doing so, it induces for spectators to see the reality in the fiction. As Lehmann says, "when theatre presents itself as a sketch and not as a finished painting, the spectators are given the chance to feel their own presence, to reflect on it, and to contribute to the unfinished character themselves". In this sense the spectators can perform an objective criticism on our society and world in Lauwer's theatre because there are a number of gaps and cracks in his theatrical illusion where reality can penetrate. This is also the point that we can find out the artists' responsibility in this era of our being.

The detection of collapsible airways contributing to airflow limitation (기류 제한에 영향을 미치는 허탈성 기도의 분석)

  • Kim, Yun Seong;Park, Byung Gyu;Lee, Kyong In;Son, Seok Man;Lee, Hyo Jin;Lee, Min Ki;Son, Choon Hee;Park, Soon Kew
    • Tuberculosis and Respiratory Diseases
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    • v.43 no.4
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    • pp.558-570
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    • 1996
  • Background : The detection of Collapsible airways has important therapeutic implications in chronic airway disease and bronchial asthma. The distinction of a purely collapsible airways disease from that of asthma is important because the treatment of the dormer may include the use of pursed lip breathing or nasal positive pressure ventilation whereas in the latter, pharmacologic approaches are used. One form of irreversible airflow limitation is collapsible airways, which has been shown to be a Component of asthma or to emphysema, it can be assessed by the volume difference between what exits the lung as determined by a spirometer and the volume compressed as measured by the plethysmography. Method : To investigate whether volume difference between slow and forced vital Capacity(SVC-FVC) by spirometry may be used as a surrogate index of airway collapse, we examined pulmonary function parameters before and after bronchodilator agent inhalation by spirometry and body plethysmography in 20 cases of patients with evidence of airflow limitation(chronic obstructive pulmonary disease 12 cases, stable bronchial asthma 7 cases, combined chronic obstructive pulmonary disease with asthma 1 case) and 20 cases of normal subjects without evidence of airflow limitation referred to the Pusan National University Hospital pulmonary function laboratory from January 1995 to July 1995 prospectively. Results : 1) Average and standard deviation of age, height, weight of patients with airflow limitation was $58.3{\pm}7.24$(yr), $166{\pm}8.0$(cm), $59.0{\pm}9.9$(kg) and those of normal subjects was $56.3{\pm}12.47$(yr), $165.9{\pm}6.9$(cm), $64.4{\pm}10.4$(kg), respectively. The differences of physical characteristics of both group were not significant statistically and male to female ratio was 14:6 in both groups. 2) The difference between slow vital capacity and forced vital capacity was $395{\pm}317ml$ in patients group and $154{\pm}176ml$ in normal group and there was statistically significance between two groups(p<0.05). Sensitivity and specificity were most higher when the cut-off value was 208ml. 3) After bronchodilator inhalation, reversible airway obstructions were shown in 16 cases of patients group, 7 cases of control group(p<0.05) by spirometry or body plethysmography d the differences of slow vital capacity and forced vital capacity in bronchodilator response group and nonresponse group were $300.4{\pm}306ml$, $144.7{\pm}180ml$ and this difference was statistically significant. 4) The difference between slow vital capacity and forced vital capacity before bronchodilator inhalation was correlated with airway resistance before bronchodilator(r=0.307 p=0.05), and the difference between slow vital capacity and forced vital capacity after bronchodilator was correlated with difference between slow vital capacity and forced vital capacity(r=0.559 p=0.0002), thoracic gas volume(r=0.488 p=0.002) before bronchodilator and airway resistance(r=0.583 p=0.0001), thoracic gas volume(r=0.375 p=0.0170) after bronchodilator, respectively. 5) The difference between slow vital capacity and forced vital capacity in smokers and nonsmokers was $257.5{\pm}303ml$, $277.5{\pm}276ml$, respectively and this difference did not reach statistical significance(p>0.05). Conclusion : The difference between slow vital capacity and forced vital capacity by spirometry may be useful for the detection of collapsible airway and may help decision making of therapeutic plans.

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