• The Korean Journal of Pharmacology
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• v.19 no.1
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• pp.15-35
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• 1983

Although it has been well known that ventricular fibrillation is the most important complication during hypothermia, much investigation has failed to show the exact nature of the etiology of ventricular fibrillation. Recently, there has been considerable research on the relationship between sympathetic activity and ventricular fibrillation under hypothermia. Cardiac muscle normally contains a certain amount of norepinephrine and the dramatic effect of this catecholamines on the cardiac muscle is well documented. It is, therefore, conceivable that cardiac catecholamines might exert an influence on the susceptibility of heart muscle to tachycardia, ventricular fibrillation and arrhythmia, under hypothermia. Hypothermia itself is stress enough to increase tonus of sympatheticoadrenal system. The normal heart is supplied by an autonomic innervation and is subjected to action of circulating catecholamines which may be released from the heart. If the reaction of the heart associated with a variable amount of cardiac catecholamines is. permitted to occur in the induction of hypothermia, the action of this agent on the heart has not to be differentiated from the direct effects of cooling. The studies presented in this paper were designed to provide further information about the cardio-physiological effects of reduced body temperature, with special reference to the role of catecholamines in ventricular fibrillation. Healthy cats, weighing about 3 kg, were anesthetized with pentobarbital(30 mg/kg) intraperitoneally. The trachea was intubated and the endotracheal tube was connected to a C.F. Palmer type A.C. respirator. Hypothermia was induced by immersing the cat into a ice water tub and the rate of body temperature lowering was $1^{\circ}C$ per 5 to 8 min. Esophageal temperature and ECG (Lead II) were simultaneously monitored. In some cases the blood pH and serum sodium and potassium were estimated before the experiment. After the experiment the animals were killed and the hearts were excised. The catecholamines content of the cardiac muscle was measured by the method of Shore and Olin (1958). The results obtained are summarized as follows. 1) In control animal the heart rate was slowed as the temperature fell and the average pulse rates of eight animals were read 94/min at $31^{\circ}C$, 70/min at $27^{\circ}C$ and 43/min at $23^{\circ}C$ if esophageal temperature. Ventricular fibrillation was occurred with no exception at a mean temperature of $20.3^{\circ}C(21-l9^{\circ}C)$. The electrocardiogram revealed abnormal P waves in each progressive cooling of the heart. there was, ultimately, a marked delay in the P-R interval, QRS complex and Q-T interval. Inversion of the T waves was characteristic of all animals. The catecholamines content of the heart muscle excised immediately after the occurrence of ventricular fibrillation was about thirty percent lower than that of the pre-hypothermic heart, that is, $1.0\;{\mu}g/g$ wet weight compared to the prehypothermic value of $1.41\;{\mu}g/g$ wet weight. The changes of blood pH, serum sodium and potassium concentration were not remarkable. 2) By the adrenergic receptor blocking agent, DCI(2-3 mg/kg), given intramuscularly thirty minutes before hypothermia, ventricular fibrillation did not occur in one of five animals when their body temperature was reduced even to $16^{\circ}C$. These animals succumbed at that low temperature, and the changes of heart rate and loss of myocardial catecholamines after hypothermia were similar to those of normal animals. The actual effect of DCI preventing the ventricular fibrillation is not predictable. 3) Administration of reserpine(1 mg/kg, i.m.) 24 hours Prior to hypothermia disclosed reduced incidence of ventricular fibrillation, that is, six of the nine animals went into fibrillation at an average temperature of $19.6^{\circ}C$. By reserpine myocardial catecholamines content dropped to $0.045\;{\mu}g/g$ wet weight. 4) Bretylium pretreatment(20 mg/kg, i.m.), which blocks the release of catecholamines, Prevented the ventricular fibrillation under hypothermia in four of the eight cats. The pulse rate, however, was approximately the same as control and in some cases was rather slower. 5) Six cats treated with norepinephrine(2 mg/kg, i.m.) or DOPA(50 mg/kg) and tranylcypromine(10 mg/kg), which tab teen proved to cause significant increase in the catecholamines content of the heart muscle, showed ventricular fibrillation in all animals under hypothermia at average temperature of $21.6^{\circ}C$ and the pulse rate increased remarkably as compared with that of normal. Catecholamines content of cardiac muscle of these animals markedly decreased after hypothermia but higher than control animals. 6) The functional refractory periods of isolated rabbit atria, determined by the paired stimulus technique, was markedly shortened by administration of epinephrine, norepinephrine and isoproterenol. 7) Adrenergic beta-blocking agents, such as pronethalol, propranolol and sotalol(MJ-1999), inhibited completely the shortening of refractory period induced by norepinephrine. 8) Pretreatment with either phenoxftenbamine or phentolamine, an adrenergic alphatlocking agent, did not modify the decrease in refractory period induced by norepinephrine. From the above experiment it is possible to conclude that catecholamines play an important role in producing ventricular fibrillation under hypothermia. The shortening of the refractorf period of cardiac muscle induced by catecholamines mar be considered as a partial factor in producing ventriculr fibrillaton and to be mediated by beta-adrenergic receptor.

• Journal of the Korean Chemical Society
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• v.67 no.5
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• pp.378-392
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• 2023

The purpose of this study is to analyze the pre-service chemistry teachers' cognition of the nature of model in process of designing and developing models using technology. For this purpose, 19 pre-service chemistry teachers' in the 3rd grade of a education college located in the central region observe experimental phenomena related to Boyle's law presented in the 7th grade science textbook and researchers required the design and development of a model related to the observed experimental results using technology. Based on previous studies, the nature of model were classified into two aspect: 'Representational aspect' and 'Explanatory aspect'. The 'Representational aspect' was classified into 'Representation', 'Abstraction', and 'Simplification', and the 'Explanatory aspect' was classified into 'Analysis', 'Interpretation', 'Reasoning', 'Explanation', and 'Quantification'. The pre-service chemistry teachers' cognition were analyzed by the classification. As a result of the study, the 'Representation' of the 'expressive aspect' was uniformized in the form of space that changes in volume, and the pressure was expressed as the Brightness inside the cylinder or frequency of color change of particles for 'Abstraction'. In the case of 'Simplification', the particle collision was expressed as a perfectly elastic collision, but there was a group that could not simply indicate the type of particle. In the 'Explanatory aspect', in the case of 'Analysis', volume was classified as a manipulated variable, and in the case of 'Interpretation', most groups analyzed the change in pressure through the collision of gas particles. However, the cognition involved in 'Reasoning' was not observed much. In the case of 'Explanation', there were groups that did not succeed in explanation because the area where the particles collided was not set or incorrectly set, and in the case of 'Quantification', there was a group that formulated the number of collisions per unit time, and on the contrary, there was a group that could not quantify the number of collisions because they could not be expressed in numbers.

• Journal of Venture Innovation
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• v.4 no.2
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• pp.77-95
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• 2021

In the midst of the progress of the 4th industrial revolution, the Corona19 Pandemic was forming giant double wave. Companies riding this wave can win, but companies that do not will fall into the wave and struggle. In connection with the 4th industrial revolution, various technologies are emerging and commercialized. At this point, consumers, especially digital natives, who have been with digital since birth, tried to find out what factors affect the intention to use these technologies and which factors have the most important influence. For this purpose, data were collected through a survey on factors affecting the intention to use FinTech technology and AR technology for 150 digital natives in their 20s. Based on this, statistical analysis was conducted and the following results were obtained. As a result of the overall analysis regardless of the type of technology, it was found that performance expectancy, effort expectancy, social influence, and habits have a positive (+) effect on digital natives' intention to use the 4th industrial technology. On the other hand, a significant influence relationship between the facilitating conditions, hedonic motivation and intention to use the 4th industrial technology was not tested. It was found that the influence was greatly influenced by social influence and habits. In the case of FinTech and AR, which were further subdivided into this study, different aspects were revealed as a result of separate analysis. In the case of FinTech technology that emphasizes utilitarian value, performance expectancy, effort expectancy, social influence, and habits had a positive (+) effect on intention to use. It was found that the influence was greatly influenced by habits and social influence. In the case of AR, which emphasizes the hedonic value, all the variables adopted in this study had a positive (+) effect on the intention to use the technology. It was found that hedonic motivation and social influence had a great influence. Combining the results of the analysis, social influence was found to be an important influence variable regardless of the type of 4th industrial technology. FinTech technologies such as mobile banking, where services are becoming more common, are habits, and in the case of AR, which has not yet been universalized and is provided mainly for entertainment, hedonic motivation was found to be an important factor. This study was able to present academic and practical implications based on the above confirmation of factors affecting digital natives' acceptance and use of the 4th industry technology.

• Journal of the Korean association of regional geographers
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• v.16 no.3
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• pp.324-337
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• 2010

We believe, 'Dokdo is clearly an inherent territory of Korea, in the light of geographical and historical facts', This paper aims to discuss Japanese multidimensional approach on the Issues of Dokdo(Takeshima) in the context of Territory Education. We considered the matter from various angles that supported by the ministry of Foreign affairs and the ministry of Education in national scale, as well as shimane prefecture government and municipality scale. Therefore, It is likely that the approach of territory education on Dokdo in Japan is variable and potential, and is temporary state of condensation, depends on Korea-Japan's political, economical, social, and international conditions. More studies of the new approach must be done for the new implications of Territory Education that embraces all meanings and events according to the disposition of neighbouring condition of Dokdo in world context, keeping out emotional and nationalist sympathies. The result of consideration in this paper are as follows. First, Territory Education in japan was focused on geography, history, Civil, Social Studies, compared with focusing on History in Korea. Second, It is centered on "korea is illegally occupying Dokdo, against which Japan has been consistently making strong protests" rather than simple historical approach. Thirdly, Their approaches seek to be succeeded the identity and importance of Territory Education to next generation rather than the present solving problem.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.3
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• pp.74-81
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• 2013

This research was performed to identify physical properties of polysulfide epoxy polymer concrete for ultra-thin bridge deck pavement, and improve domestic applicability. With the optimum mix ratio determined from mixing experiments of polymer concretes, compressive, flexural, and bond strength were tested to identify its strength properties along with the freezing-thawing resistance test to evaluate its durability in harsh environments. As a result, the tested polymer concretes showed excellent performance in strength and deflection characteristic and all tested strength satisfied the criteria of American Concrete Institute. Moreover, it had better performance under variable temperatures comparing to other existing pavement materials. By the results of freezing-thawing resistance test and strength measurement for specimens underwent the freezing-thawing process, it can be judged that there is no such problem to the concrete's durability. In conclusion, the newly developed polymer concrete in this research has appropriate properties for use in ultra-thin pavement on bridge deck, and moreover it has superior applicability in comparison with former materials due to its improved temperature sensitivity.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.68-79
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• 2008

Because local cities are different from large cities, they need to reflect their own characteristics of housing market. Thus in order to obtain useful implications for the establishing sound housing market in Jinju City, this paper investigated the characteristics of spatial distribution and determinant factors that affect apartment price in Jinju City. GIS representation of the apartments showed that most of old and small apartments were built in 'land readjustment project' areas executed in 1970s. On the contrary, new and large scale apartment complexes were built quite recently and distributed in the western and southern parts of the city. Next, in order to examine the factors which affect apartment price, this paper subtracted firstly several variables from the related studies. However in order to avoid multi-colinearity, variables were summarized by means of factor analysis. Then, setting apartment price as a dependant variable, 12 hedonic price models were established with 33 independent variables. As results, building age, floor area, accessibility to university and hospital, accessibility to arterial road, and stair-type building were turned out to be significant. These results will be used in making the supply and allocation plan of urban facilities and housing. Finally as conclusions this paper emphasized the need of periodic analysis of local housing market and establishing detailed housing information systems.

• Korean Journal of Veterinary Research
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• v.12 no.1
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• pp.37-50
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• 1972

Another comparison of alveolar gas pressures, in a continuously rebreathing dog lung, with pulmonary arterial (mixed venous) blood, again showed alveolar pressures to be the higher for $CO_2$ and usually $O_2$ (positive ${\Delta}Pco_2$, and ${\Delta}Po_2$). ${\Delta}Pco_2$ was almost invariably positive, it was independant of time and of plasma pH changes produced by acid or bicarbonate infusion, but proportional to blood $CO_2$ level. It was seemingly little affected by the distribution or magnitude of blood flow nor did it result from failure of $CO_2$ equilibrium within the blood, but it did rise with carbonic anhydrase inhibition. ${\Delta}Po_2$ was more variable and sometimes negative, particularly at low blood flow rates. It seemed in dependant of time, and plasma pH changes, apart from an inverse relationship with that resulting from $CO_2$ changes. It existed despite considerable potential for gas exchange, and was unaffected by inhibition of the $CO_2$ reactions.

• Economic and Environmental Geology
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• v.30 no.6
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• pp.553-566
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• 1997

Origin, behavior and enrichment of environmental toxic elements from the Deokpyeong area were investigated on the basis of major, trace and rare earth element geochemistry. Coaly metapelites of the Deokpyeong area are subdivided into grey phyllite, dark grey phyllite, coaly slate and black slate, which are interbedded along the Ogcheon Supergroup. The coaly slate had been mined for coal, but mining is closed. The coaly and black slates are lower contents of $SiO_2$ and $Al_2O_3$, and higher contents of LOI, CaO, $Na_2O$ and BaO as compared with the phyllitic rocks. Rare earth elements are highly enriched in the coaly and black slate. Average compositions (ppm) of minor and/or environmental toxic elements in the coaly and black slate are revealed as As=127, Ba=30,163, Cd=18, Cr=740, Cu=84, Mo=378, Pb=43, Sb=12, Se=44, U=144, V=8,147 and Zn=292, which are extremely high concentrations than those in the NASC compositions. Major elements (average enrichment index; 5.34) in the coaly metapelites are mostly depleted, excepting $P_2O_5$ and BaO, normalized by NASC. Rare earth elements (average enrichment index; 1.48) are enriched in the coaly slate. On the basis of NASC, minor and/or environmental toxic elements in the coaly metapelites were strongly enriched of all the elements with the exception of Co, Cs, Ni and Sr. Average enrichment index of trace elements in coaly metapelite is 31.51 (coaly slate; 51.94 and black slate; 15.46). Especially, enrichment index of potentially toxic elements (As, Ba, Cr, Cu, Mo, Ni, Sb, Se, U, V and Zn) of the rock is 46.10 (grey phyllite; 7.15, dark grey phyllite; 4.77, coaly slate; 88.96 and black slate; 22.11). These coal formations were deposited in basin of boundary between terrestrial and marine environments deduced to carbon, sulfur (C/S=2.2 to 275.7), trace and rare earth elements characteristics. Irregular behavior and dispersion between major, minor and rare earth elements of those metapelites indicates a variable source materials, incomplete mixing of differential source and/or reequilibrium of diagenesis and metamorphism.

• The Journal of Art Theory & Practice
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• no.15
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• pp.83-109
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• 2013

The study mainly discusses appreciation of interactive art works seen from the perspective of play attributes that make spectators glimpse the truth of things. The general studies of interactivity, as one of remarkable features in contemporary art, are regarding the relation between the effects of digital media and interactivity as well as video games. From the preceding discussion, I analyze the effects of the appreciating interactive art works which are focused on new sensory systems, the methods to intuit the essence of the art works. Based on the concept, as I investigate the play attributes found in the interactive art works, this study gives attention to the possibility that if the spectators can reach the inherent aspects of interactive art works, while interacting them. Thus to discuss the properties of the play, this article studies play concept of Johan Huizinga(1872-1945), psychologist and anthropologist and play theory of Hans Georg Gadamer(1900-2002) who considers play as a metaphor for art. As Huizinga thinks acting is the important attribute of play, Gadamer argues whenever the term 'play' is used, we should think about 'to-and tro movement' and the movement is absence of goal as well as endlessly renews through repetition. Then what we should pay attention to, seeing the essence of art and play as similar? That is, Gadamer claims, we can understand the truth of things through the play. To apply the play concept to the interactive art works, I research the works of Maurice Benayoun(1957 - ), French interactive artist. By employing interactivity, he attempts to extend and affect the experience of his art works to one of social phenomenon. Striving this, spectators can widen and deepen the breadth of their intuition and recognize the essence of art works. It is the interactive art works that can be the apex of the transformation of structure from the play to the art. The endless repetitive process of play, which is free creation-annihilation process, is similar with the interactive experience of spectators that is variable, de-centered, and multi-sensory. The pure action of the play lets us recognize, sense and accept the world and through the system of interactive art experience, we can expand the horizons of perception. Interactive art works with these play attributes are capable of playing the role that the spectators glimpse the truth of things and experience the world around them.

• Journal of Korean Foot and Ankle Society
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• v.18 no.2
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• pp.62-67
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• 2014

Purpose: Reconstructive surgeries for equinocavovarus foot deformities are quite variable, including hind-midfoot osteotomy or arthrodesis, soft tissue procedure, tendon transfers, etc. Comprehensive evaluation of the deformity and its etiology is mandatory for achievement of successful deformity correction. Few studies in this field have been reported. We report on the clinical and radiographic outcome of reconstruction for cavovarus foot deformities. Materials and Methods: The study is based on 16 feet with cavovarus foot deformities that underwent bony and soft tissue reconstructive surgery from 2004 to 2008. We evaluated the etiologies, varieties of surgical procedures performed, pain score, functional scores, and patient satisfaction and measured the radiographic parameters. Results: The average age at the time of surgery was 39.4 years old, with a male/female ratio of 9/4 and an average follow-up period of 23.9 months (range, 12~49 months). The etiologies of the cavovarus deformity were idiopathic 7 feet, residual poliomyelitis 5 feet, Charcot-Marie-Tooth disease 2 feet, and Guillain-Barre syndrome and hemiplegia due to cerebrovascular accident sequela 1 foot each. Lateral sliding calcaneal osteotomies were performed in 12 feet (75%), followed by Achilles tendon lengthening and plantar fascia release in 11 feet (69%), and first metatarsal dorsiflexion osteotomy/arthrodesis and tendon transfer in 10 feet (63%). Visual analogue scale pain score showed improvement, from an average of 4.2 to 0.5 points. American Orthopaedic Foot and Ankle Society ankle-hindfoot score showed significant improvement, from 47.8 to 90.0 points (p<0.05). All patients were satisfied. Ankle range of motion improved from $27.5^{\circ}$ to $46.7^{\circ}$. In radiographic measurements, calcaneal pitch angle improved from $19.1^{\circ}$ to $15.8^{\circ}$, Meary angle from $13.0^{\circ}$ to $9.3^{\circ}$, Hibb's angle from $44.3^{\circ}$ to $37.0^{\circ}$, and tibio-calcaneal axis angle from varus $17.5^{\circ}$ to varus $1.5^{\circ}$ Conclusion: We achieved successful correction of cavovarus foot deformities by performing appropriate comprehensive reconstructive procedures with improved functional, radiographic measures and high patient satisfaction.