• Title/Summary/Keyword: acting situation

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Experimental Study of the Anastomosis with Suture vs Non-suture Techinique (미세 혈관 접합술에서 봉합적 수기와 비봉합적 수기의 실험적 비교 연구)

  • Chung, Duke-Whan;Han, Chung-Soo;Yoo, Myung-Chul;Nam, Gi-Un;Sun, Seung-Deok
    • Archives of Reconstructive Microsurgery
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    • v.3 no.1
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    • pp.45-53
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    • 1994
  • Suture microvascular anastomosis is time-consuming and tedious and demands long and continuous training. Techinique of anastomosis of microvessel was presented interrupted suture and continuous suture. Recently the unilink instrument system is created as a fast and simple method to achieve high patency rates without long and continuous training in the anastomosis of small vessels. The author experimentally studied the femoral artery of 20 mice(0.5-1.0mm, av. 0.7mm), the femoral vein of 20 mice(0.8-1.6mm, av. 1.2mm) after anastomosis with interrupted suture in 20 cases and continuous sutre in 20 cases. For the unilink apparatus we used the carotid arteries of 15 cases in 14 rabbits(1.0-1.6mm, av. 1.3mm) and facial veins of 12 cases in 14 rabbits(0.9mm-2.2mm, av. 1.5mm). A total of 27 arterial and venous anastomoses were performed. We examined the postoperative patency at immediate, 2 weeks, and 8 weeks. The results were as followings, 1. In the arterial anastomosis the rate of patency was 90%(18/20) in interrupted suture, 90%(18/20) in continuous suture and 93%(13/15) in unilink apparatus. In the venous anastomosis the rate of patency was 90%(18/20) in interrupted suture, 80%(16/20) in continuous suture and 100%(9/9) in unilink apparatus. 2. The mean time for completion of the arterial anastomosis were 12.2 minutes in interrupted suture group, 10.3 minutes in continouous suture group and 8.5 minutes in unillnk apparatus group. The mean time for completion of the venous anastomosis were 13.6 minutes in interrupted suture group, 11.0 minutes in continuous suture group and 6.2 minutes in unilink apparatus group. 3. At the histological examination of suture group, hyperplastic reaction of middle layer and subintimal hyperplasia were observed. In unilink apparatus group, the endothelium layer was continued and the thickness of vessel wall was decreased due to moderate atrophy of the media and mild degree of nonspecific chronic inflammation were seen around the unilink apparatus. 4. No significants was noticied in foreign body reaction among the interrupted, continuous and unilink apparatus group. 5. A case of the arterial anastomosis was released with acting out at 15 minutes after operation. 6. The important factors in the technical problems were accurate apposition of the cut vessel edges in suture group and the proper selection of the ring size and optimal fitting between two rings in unilink apparatus group. Even though the outer diamater of vessel in suture group was different from that in unilink apparatus group the unilink method provides a very safe, fast, and simple way to perform microvascular anastomoses especially in anastomosis of vein. But howerver suture was needed in vessels below 1 mm outer diamater. In that situation continuous suture was benefit than the interrupted suture in operation time.

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Simulation of Evacuation Dynamics of Three Types of Pedestrians with Morality (도덕성을 가지는 세 종류의 보행자에 대한 긴급대피 동역학 시뮬레이션)

  • Lee, Sang-Hee
    • Journal of the Korea Society for Simulation
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    • v.20 no.1
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    • pp.79-85
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    • 2011
  • The problem of evacuating pedestrians from a room or channel under panic conditions is of obvious importance in daily life. In recent years, several computer models have been developed to simulate pedestrian dynamics. Understanding evacuation dynamics can allow for the design of more comfortable and safe pedestrian facilities. However, these models do not take into account the type and state of mind of pedestrians. They deal with pedestrians as particles and the state of mind as a social force, which is represented by conservative and long-range interactions between individuals. In this study, I used the lattice model proposed in my previous study to explore the evacuation behavior of pedestrians with morality. In this model, three types of pedestrians are considered: adults, children, and injured people. Collisions between adults and children result in injured people. When the number of injured people continuously in contact with each other reaches a given value k, the injured people are removed from the lattice space. This situation is the same as that in which pedestrians start stepping over injured people. This behavior was interpreted as the morality of pedestrians. Simulations showed that the evacuation showed down and eventually became jammed owing to the injured people acting as "obstacles" in relation to the morality k.

A Study on the Benefits and Issues of 360-degree VR Performance Videos (360도 VR공연영상의 효과와 문제점 연구)

Ground Separation Test to Verify Separation Stability of External Fuel Tank (외부연료탱크의 분리 안정성 검증을 위한 지상 분리시험)

  • Kim, Hyun-gi;Hong, Seung-ho;Ha, Byung-geun;Kim, Sung-chan;Lee, Jun-won
    • Journal of Aerospace System Engineering
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    • v.16 no.3
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    • pp.99-104
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    • 2022
  • Aircraft pylon connects the engine or external stores to the main wing, and transfers the load acting on the pylon to the main structure of the aircraft. In particular, it should perform the function of separating the external store mounted on the pylon in case of emergency or mission performance. At this time, if the separation of the external store is not performed properly due to peripheral air flow or functional problems during the separation process of the external store, it may seriously impact the survivability of the aircraft. For this reason, to apply an external attachment to an aircraft, it is necessary to prove the stability of the external attachment in the separation situation in advance. In this paper, we present the result of the ground separation test performed to confirm that the external fuel tank, which is an external attachment, can be safely separated from the pylon. As a result of the test, the separation movement of the external fuel tank was measured with a high-speed camera, and the stability of the separation of the external fuel tank from the pylon were confirmed through the ground separation test. Additionally, the test result provides basic data for the stability evaluation of the separation of external attachments in actual aircraft.

A Bible Didactical Approach to Bibliodrama on the Metaverse Platforms (메타버스 플랫폼을 통한 비블리오드라마 구현에 대한 성서 교수학적 접근)

  • Seo, Mikyoung
    • Journal of Christian Education in Korea
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    • v.69
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    • pp.45-75
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    • 2022
  • The purpose of this study is to explore the implementation of Bibliodrama on the metaverse platforms. In other words, to create interesting and effective Bible education for modern learners, this study took a didactical approach to the implementation of Bibliodrama through the metaverse. The main reason to be enthusiastic about using the metaverse for education is because users, who have been only content consumers, now able to experience and create values. As a Bible didactical approach, Bibliodrama is a an emphatical and communicative learning method in the form of role play. Bibliodrama seeks to interact with the world of the learner and the world of the Bible through improvisational acting, to study the Bible. Through the Bible didactical approach, the meeting of Bibliodrama and the metaverse can have a positive effect on modern learners, in terms of improving learning environment and, above all else, increasing learning interest. In terms of biblical didactics, implementing Bibliodrama in the metaverse has the following advantages. First, it helps to construct a dramatic situation and environment so that the meaning of the biblical text can be proved relevant to today's learners, not something belonging to the past. Second, in the metaverse, the historical space and characters of the Bible can be realized in virtual reality to produce a 'situational play'. Demonstrating freedom, imagination and creativity in the metaverse learners play in Bibliodrama. This way they also become aware of the hidden meaning of the blank pages in the Bible. Third, the metaverse environment is not static but dynamic and interactive; Bibliodrama pursues an interpretation that harmonizes spirit and body. Therefore, through the dynamic activities of discovering the meaning and significance of the Bible, it is possible to form a holistic faith in which spirit and body act as one.

A Study about Development of Environment Printing Technology and $CO_2$ (환경 인쇄 기술의 발전과 인쇄물의 $CO_2$ 발생량에 관한 연구)

  • Lee, Mun-Hag
    • Journal of the Korean Graphic Arts Communication Society
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    • v.30 no.3
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    • pp.89-114
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    • 2012
  • For as to world, the concern about the environment problem is enhanced than any other time in the past because of being 21 century. And the environment problem is highlighted as the world-wide issue. The time of the environment problem intimidates the alive of the mankind and presence of an earth over the time. It becomes the essentiality not being selection in the personal living or the economical viewpoint now to prepare for the climatic modification. As to the company management, the green growth period which it excludes the environment management considering an environment, cannot carry on the company the continued management comes. That is, in the change center of the management paradigm, there is the environment management. Nearly, the greenhouse gas which the publication industry is the environmental toxic material like all industries is generated. The greenhouse gas is ejected in the process of running the manufacturing process and print shop of the various kinds material used as the raw material of the book. Particularly, the tree felling for getting the material of the paper is known to reach the direct influence on the global warming. This study does according to an object it considers and organizes the environment parameter based on this kind of fact as to the publication industry. And it is determined as the reference which is used as the basic materials preparing the case that carbon exhaust right transaction(CAP and TRADE) drawing are enforced in all industries and is sustainable the management of the publication industry and reduces the environmental risk among the company many risk management elements and plans and enforces the publication related policy that there is a value. In the printing publication industry, this study tried to inquire into elements discharging the environmental pollutant or the greenhouse gas. Additionally, in the printed publication production process, it tried to inquire into the effort for an environment-friendly and necessity at the printing paper and the printers ink, regarded as the element discharging the greenhouse gas all kinds of the printing materials, operation of the print shop and all kinds of the machines and recycle process, and etc. These considerations make these industrial field employees aware of the significance about a conservation and environmental protection. They try to give a help in the subsequent study producing quantitatively each environmental parameter emission of green house gas. This makes the calculation of the relative $CO_2$ output reproached ultimately possible. Meanwhile, in a sense, many research protects and improving an environment in connection with the contents of research at the printing publication industrial field is in progress. There will be the voluntary human face that it has to protect an environment but this can not do by the outside factor according to all kinds of environment related law and regulation. Anyway, because of acting on company management as the factor of oppression, the increase of this environment-related correspondence cost could know that the research that the environment loading relates with a procurement and development, environment management system introduction, quality control standard, including, normalizing including a material, and etc. through the part of the effort to reduce the cost low was actively in progress. As to the green growth era, as follows, this paper prescribed the subject and alternative of the print publication industry. It is surrounded by the firstly new digital environment and the generation of the subject. And secondly the printing industry is caused by the point of time when the green growth leaves by the topic which is largest in the global industry and it increases. The printing publication industry has to prepare the bridgehead for the environment-friendly green growth as the alternative for this resolution with first. The support blown in each industry becomes the obligation not being selection. Prestek in which the print publishing was exposed to spend many energies and which is known as the practice of the sustainable print publishing insisted that it mentioned importance of the green printing through the white pages in 2008 and a company had to be the green growth comprised through the environment-friendly activity. The core management for the sustainable printing publication industry presented from Presstack white pages is compacted to 4 words that it is a remove, reduce, recover, and recycle. Second, positively the digital printing(POD) system should be utilized. In the worldwide print out market, the digital printing area stops at the level of 10% or so but the change over and growth of the market of an analog-to-digital will increase rapidly in the future. As to the CEO Jeff Hayes of the Infoland, the offset print referred to that it of the traditional method got old and infirm with the minor phase of the new printing application like the customer to be wanted publication and the print of the digital method led the market. In conclusion, print publishers have to grasp well the market flow in the situation where a digitalization cannot be generalized and a support cannot avoid. And it keeps pace with the flow of the digital age and the recognition about the effort for the development and environment problem have to be raised. Particularly, the active green strategy is employed for the active green strategy.

Comparative Study on Nursing Education System of Korea and China (한.중 간호교육제도 및 교육과정 비교연구)

  • Moon, Heui-Ja;Kim, Kwang-Joo;Park, Shin-Ae;Kim, Il-Won;Park, Hua-Shun
    • Journal of East-West Nursing Research
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    • v.7 no.1
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    • pp.32-47
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    • 2002
  • This study is a descriptive comparative investigated one to analyze nursing education system and curriculum of Korea and China trans-culturally. 1) Education System The basic level of nursing education in Korea consisted of 65 3-year- junior college of nursing (7379 students) and 48 4-year-bachelor of nursing college (2345 students) in 2000 showing more 3-year-junior college of nursing and its students. In China, western nursing as well as Chinese nursing education system were operating. In 2000, 501 western school of middle technical nursing, 29 school of middle technical nursing of middle level education, and 89 3-year western and 24 Chinese junior college of nursing, and 42 4-year western bachelor of nursing college and 10 Chinese of high level education have been established. The presence of Chinese school of middle technical nursing system seemed to be in slower development in nursing than Korea, but that of Chinese nursing education seemed to be advanced with its national identification prior to Korea. Post graduate continuous education for RN-Diploma and RN-BSN program has been opened as in Korea. The Hosa(護士) system in school of middle technical nursing in China reflects lower level of education than Korea. But it can be a merit, other than in Korea, without nurses aids, when they are acting under supervision of nurses and led by them, and there presents a special course for promotion up to high level education. Graduate school in Korea is divided into general type opening a curriculum for MS in 1960 and as of 2000, 21 general types for majoring in nursing. The PhD course in Korea was established in 1978, and after that the PhD courses have been opening in 14 universities at present. China established master degree course in 1991 and as of 7 colleges are ongoing, and the doctoral course is now under planning, resulting slower development than Korea. 2) Education of theory and clinical practice in Korea and Chine (1) Korea's 3-year junior nursing college have 51 subjects, 49 subjects in China, which was not different. China was following education of ideology and medical. 4-year Bachelor of Science College has 92 subjects in Korea with cultural subjects and essential major studies/elective in theory education in Korea, while 63 subjects in China, showed wider selection in Korea's education. (2) Korea's 3-year and 4-year nursing colleges performed clinical practice education parallel with theoretical education for a certain period, block or theory/practice system. While China's 3-year and 4 or 5-year-colleges educated the theory first and then practice for one year in the last grade, integrating each situation of the departments and the theory. (3) Korea's oriental nursing theory in nursing education was performed in 28 colleges of 65 nationwide ones of 3-year junior nursing colleges, but only one school was educating clinical practice. In 4-year bachelor of nursing colleges, the oriental nursing theory was done in 14 among 48 investigated. And 1-4 subjects of them were doing, and 4 schools performed of clinical practice, showing more reinforced than the junior colleges. China's 3-year and 4-5-year western nursing colleges taught two subjects of Chinese medicine nursing. China's 3-year & 4-5-year College of Chinese medicine nursing, theory of Chines medicine nursing education taught eight subjects. (4) 5-year colleges of Chinese medicine western integrated nursing, theory of Chinese medicine nursing education consisted of twelve Chinese medicine nursing subjects and two of Chinese medicine western integrated nursing subjects. China was tempting a new development of a pattern of Chinese medicine nursing subjects reinforced. 3) The verification of Korean and Chinese nurse's license. The verification test of Chinese nurses license is differentiated at the level of education other than in Korea. Expire date is 2 years and a qualified test must be done to a renewal. And the continuing education hours are 72 per year, which is more enforced than Korean nurses (10 hours a year). In accordance with WTO regulations, we should prepare for opening foreign hospital, educating oriental nursing subjects. And on this, it is recommendable to settle a basic frame research to run the oriental nursing practice ongoing. 1. It is desirable to develop the oriental nursing subjects to apply its idea to the western nursing and differentiate Korean nursing. 2. It is desirable to certify oriental nurse's characters, to expand and develop the nursing areas to practice it, and to establish the oriental nursing system. 3. It is expectable to promote Korean nursing specialization to develop the oriental nursing as a professional and to create its demand.

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평행식 진동탄환 암거 천공기의 연구 (IV)(V)-실기 설계 제작 및 보장실험-Development of Balanced-Type Oscillating Mole Drainer(IV)(V)

  • 김용환;이승규;서상용
    • Journal of Biosystems Engineering
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    • v.2 no.1
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    • pp.7-24
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    • 1977
  • This paper is the forth and fifth one of the study on balanced type oscillating mole drainer. In the light of the results from previous reports about the model tests, some design criteria were established and a prototype machine was set up for experimental purpose. Motion characteristics and functionof the each parts of the machine were checked and analyzed. After that, performance tests of the prototype machine were carried out in thefield. Obtained results are summarized as follows ; 1. Ten centimeter of the bullet diameter was determined so as to be able to attach it to the tractors with capacity of 30 PS to 40 PS. 2. To maintain the balance between the moments of the front shank and rear shank, the oscillating amplitude of the rear bullet was determined to be larger than that of the front bullet. At the same time , the oscillating direction of the rear bullet was designed with the inclines of ten to thirty degrees. 3. An octagonal dynamo transduced was developed for measuring the compressive force of the upper link is measuring the draft force of the machine. Acceptable linear relationship between forces and strain responses from O.D.T. was obtained. 4. Analysing the balancing mechanism of the acting part of the machine , it was found that the total draft force of the machine was equal to the difference between the sum of the draft force produced from the right and left side bending moments of the lower drawber and the compressive force on the upper link. 5. There are acceptable linear relationship between the strain and twisting moment by driving shaft, and between strain and shank moment. Above results enable us to carry out the field experiment with prototype machine. 6. When the test machine was used in the field, it was possible to reduce the oscillating acceleration by forty percent in average as compared it with the single bullet mole drainer. 7. When the test machine was used under the oscillating condition, the dratt torce was reduced by 27 percent to 59 percent as compared it with the test machine under non-oscillating condition, while the draft force was increased by 7 percent to 20 percent as compared it with the mole drainer having oscillating single bullet. The reasoning behind this fact was considered as the resistance force due to the rear shank and bullet. 8. As the amplitude and frequency of the bullet were increased, the torque was increased accordingly. This tendency could be varied with the various characteristics of the given soils. And the larger frequency and amplitute, the more increasing oscil\ulcornerlating power but decreasing draft brce were needed, and draft force was increased as the velocity was increased.9. When the amplitude of the rear bullet was designed to be larger than that of the front bullet, the minimum value of the moment was lowered and oscillating acceleration was reduced. And when the oscillating direction of the rear bullet was declined back\ulcornerwards, oscillating acceleration was increased along with the increasing angle of decli\ulcornernation. When the test machine was operated in high speed, the difference between maximum moments and minimum ones became narrow. This varying magnitude of moments appeared on the moment oscillogram seems to be correlated to the oscillating acceleration and draft force. 10. From the analysis of variance, it was found that those factors such as frequency, amplitude, and operating velocity significantly affected in the oscillating acceleration, the draft resistance, the torque, the moment, and the total power required. And interaction between frequency and amplitude affected in the oscillating acceleration. 11. Within the given situation of this study, the most preferable operating conditions of the test machine were 7 Hz in oscillating frequency, 0.54 m/sec in operating velocity, and 39.1 mm in oscillating amplitude of front and rear bullets. However, it is necessary to select the proper frequency and magnitude of oscillation depending on the soil properties of the field in which the mole drainer is practiced by use of a bal1nced type oscillating mole drainer. 12. It is recommended that a comparative study of the mole drainers would be performed in the near future using two separate balanced oscillating bullet with the one which is operated by oscillating the movable bullet in a single cylinder or other balanced type which may be single oscillating bullet with spring, damper or balancing weight, and that of thing. To expand the applicability of the balanced type oscillating mole drainer in practical use, it is suggested to develop a new mechanism which perform mole drain with vinyl pipe or filling material such as rice hull.

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Studies about Acceptance of Songs or Sounds 'Sori(唱)' appeared in Musical Comedy performed in Korean Traditional Music and Changeable Aspects Thereof - Centering around Korean Musical Group, Taroo - (국악뮤지컬에 나타난 소리(창(唱))의 수용 및 변화양상 연구 - "'국악뮤지컬집단 타루'를 중심으로" -)

  • Jung, Hyewon
    • Journal of Korean Theatre Studies Association
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    • no.49
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    • pp.5-47
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    • 2013
  • Among the styles of performing arts, perhaps the genre that has attracted the largest audience would be musical. Popularity of musical has brought diverse changes in our performing arts market, and, upon emerging another musical genre, called 'Korean Traditional Musical Comedy,' it has been well-received by the audiences. 'Korean Traditional Musical Comedy' is a word that are formed by merging two other terms such as 'Korean Traditional Music' and 'Musical (Comedy).' In the meantime, however, it has yet some problems in order to be defined as the genre that has concrete concepts. It is because the term such as Korean Traditional Musical Comedy was created being closely associated with a marketing purpose rather than a term that defines the characteristics of a genre of performing arts. Although this new musical genre has drawn attentions of many audiences by adding 'Musical Comedy' to 'Korean Traditional Music' that was not quite popular to the public, it still does not have any established forms so that there is a fine line between "Korean Traditional Musical Comedy" and another genre like traditional style folk opera ("Changgeuk"). Looking at the characteristics of the musical work called 'Korean Traditional Musical Comedy, in general, first of all, it is a performance where music and drama are played. Here, the distinctive characteristic of this musical is that 'Korean Traditional Music' is sung. And the kinds of Korean traditional musics being sung are mainly Pansori (dramatic story-singing) and folk-songs, and, in most cases, Korean traditional musical instruments are being used as accompanying music. In this paper, the researcher investigated the aspects of experiment centering around Korean Musical Group, Taroo. These days, various experiments has been repeated not only for the works of Taroo but other musical work presently called 'Korean Traditional Musical Comedy' also. Having encompassed overall performance factors including use of musical instruments, dance, acting, materials for drama as well as music in drama, the researcher has gone through experiments repeatedly. Meanwhile, however, the subject matters that make 'Korean Traditional Musical Comedy' mostly attractive to the audiences are music and songs or sounds. ["Sori" also called "Chang" (唱)] Particularly, under the current situation of our musicals, the role of "Sori" is extremely important. The factor that plays absolutely most important role in acceptance and transformation of "Sori" is the created Pansori. Since the created Pansori is composed with new rhythmic patterns and new narrative poems, it tells the present story. Also it draws good responses from the audiences owing to easy conveyance of dialogues. And, its new style brings diversification to organization of musical instruments, so then this leads to the arrangements of music for Korean traditional music instruments, as well as instrumental music ensemble, orchestra, and jazz band, etc. Likewise, upon appearing creative musics in 'Korean Traditional Musical Comedy,' professional music and vocal compositions have begun to emerge naturally. And, the song specialist and writer, of course, staffs including direction, lighting, and sounds, etc are required. That is, professional composition method are forced to be introduced to all areas. Other than this, there are many music pieces which are based on our unique songs and sounds ("Sori") and such traditional factors as use of lead singer for ceremony or chorus, and the method that puts weight on Pansori. Accordingly many things accomplished. However, it is required that 'Korean Traditional Musical Comedy' go through numerous discussions and more experiments. Above all, the most important things are the role of actor and actress, and their changes, and training of actor and actress further. Good news is there are good audience responses. 'Korean Traditional Musical Comedy' is an open genre. As musicals are divided into several domains according to the characteristics thereof, 'Korean Traditional Musical Comedy' will be able to show its distinctive features in various styles according to embodiment.

Dynamic Limit and Predatory Pricing Under Uncertainty (불확실성하(不確實性下)의 동태적(動態的) 진입제한(進入制限) 및 약탈가격(掠奪價格) 책정(策定))

  • Yoo, Yoon-ha
    • KDI Journal of Economic Policy
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    • v.13 no.1
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    • pp.151-166
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    • 1991
  • In this paper, a simple game-theoretic entry deterrence model is developed that integrates both limit pricing and predatory pricing. While there have been extensive studies which have dealt with predation and limit pricing separately, no study so far has analyzed these closely related practices in a unified framework. Treating each practice as if it were an independent phenomenon is, of course, an analytical necessity to abstract from complex realities. However, welfare analysis based on such a model may give misleading policy implications. By analyzing limit and predatory pricing within a single framework, this paper attempts to shed some light on the effects of interactions between these two frequently cited tactics of entry deterrence. Another distinctive feature of the paper is that limit and predatory pricing emerge, in equilibrium, as rational, profit maximizing strategies in the model. Until recently, the only conclusion from formal analyses of predatory pricing was that predation is unlikely to take place if every economic agent is assumed to be rational. This conclusion rests upon the argument that predation is costly; that is, it inflicts more losses upon the predator than upon the rival producer, and, therefore, is unlikely to succeed in driving out the rival, who understands that the price cutting, if it ever takes place, must be temporary. Recently several attempts have been made to overcome this modelling difficulty by Kreps and Wilson, Milgram and Roberts, Benoit, Fudenberg and Tirole, and Roberts. With the exception of Roberts, however, these studies, though successful in preserving the rationality of players, still share one serious weakness in that they resort to ad hoc, external constraints in order to generate profit maximizing predation. The present paper uses a highly stylized model of Cournot duopoly and derives the equilibrium predatory strategy without invoking external constraints except the assumption of asymmetrically distributed information. The underlying intuition behind the model can be summarized as follows. Imagine a firm that is considering entry into a monopolist's market but is uncertain about the incumbent firm's cost structure. If the monopolist has low cost, the rival would rather not enter because it would be difficult to compete with an efficient, low-cost firm. If the monopolist has high costs, however, the rival will definitely enter the market because it can make positive profits. In this situation, if the incumbent firm unwittingly produces its monopoly output, the entrant can infer the nature of the monopolist's cost by observing the monopolist's price. Knowing this, the high cost monopolist increases its output level up to what would have been produced by a low cost firm in an effort to conceal its cost condition. This constitutes limit pricing. The same logic applies when there is a rival competitor in the market. Producing a high cost duopoly output is self-revealing and thus to be avoided. Therefore, the firm chooses to produce the low cost duopoly output, consequently inflicting losses to the entrant or rival producer, thus acting in a predatory manner. The policy implications of the analysis are rather mixed. Contrary to the widely accepted hypothesis that predation is, at best, a negative sum game, and thus, a strategy that is unlikely to be played from the outset, this paper concludes that predation can be real occurence by showing that it can arise as an effective profit maximizing strategy. This conclusion alone may imply that the government can play a role in increasing the consumer welfare, say, by banning predation or limit pricing. However, the problem is that it is rather difficult to ascribe any welfare losses to these kinds of entry deterring practices. This difficulty arises from the fact that if the same practices have been adopted by a low cost firm, they could not be called entry-deterring. Moreover, the high cost incumbent in the model is doing exactly what the low cost firm would have done to keep the market to itself. All in all, this paper suggests that a government injunction of limit and predatory pricing should be applied with great care, evaluating each case on its own basis. Hasty generalization may work to the detriment, rather than the enhancement of consumer welfare.

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