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The object and method of this thesis is to inquire and analyse the Technological change and Economics of Development. The Contents are (1) The Production Function and the ingredient of Technological change, (2) Measurement of Technological change, (3) Embodied Technological change and the Measurement of bias. I Would like to draw a Conclusion about this thesis. Economics of scale can be measured by the complete specification and estimation of production functions at different point in time, or alternatively, through a number of shortcut procedures. If they are carefully done, engineering estimates may constitute a satisfactory shortcut. Our compendium of existing engineering estimates of economies of scale in different industries indicates that many industries may be subject to economics of scale but also that the magnitude of the scale economics tends to vary considerably from industry to industry. The increases in actual plant size that have occurred in most industries may indicate that scale economics increase over time. The study of the changes in the elasticity of substitution has led to two basic conclusions. First, we have found that the elasticity of substitution is generally less than one in industry and probably considerably lower than the elasticity of substitution in agriculture. Second, as more modern technology is adopted, the elasticity of substitution declines. Both findings suggest that as a country develops its ability to substitute labor for capital decreases. If other things would remain equal, this factor alone could be expected to make unemployment a more serious problems as development occurs. Secular changes in technical efficiency have traditionally been measured in terms of disembodied shifts in the constant term of a production function that is restricted in its other parameters. The startling conclusion emerging from such studies has been that an overwhelming proportion of the increase in output (as high as 90 percent in some instances) can be attributed to increases in labor productivity, only the small remainder is due to capital deepening. Such findings imply that the payoff to increases in the rate of investment is relatively small-which does not seem plausible. This shortcoming has led to the formulation of "embcdiment" hypotheses, which admit qualitative changes in the factors of production in the process of development. In the process of formulating embodiment hypotheses, it has been possible to define the bias in technological progress in terms of changes in factor intensity. It is of crucial importance to determine if a certain production process is capital savings or labor saving. Furthermore, changes in factor intensity, combined with changes in the elasticity of substitution between factors, determine changes in factor shares as development occurs and the quantity of output increases. The evidence on these issues is scanty. It would appear that in the United States, at least, technological progress in agriculture has been characterzed by an increase in the capital-labor ratio, which combined with an elasticity of substitution greater than one, has led to a decline in the relative share of labor in agriculture. Our study of the technological parameters of production and of their dynamic properties points to some seeds of trouble that will eventually mature, leading to the conclusion that development may not be as smooth and equilibrating a process as development statics and neoclassical dynamics has generally described it. For example, the existence of economics of scale suggests that neoclassical marginal productivity considerations may be insufficient for explaining the functional distridution of income. Variations in the economics of scale parameter among industries or technologies and over time suggest that some industries may be dominated by large firms and others by small firms. Moreover, if there are different technologies in the same industry, no one of which is dominant in all respects, these differences may explain how large and small firms may coexist. So, too, if the elasticity of substitution decreases either over time or as technology becomes more modern, we would expect that LDCs will have difficulty in absorbing their relatively abundant endowments of unskilled labor. There are still other problems less amenable to explanation on the basis of the traditional paradigm of neoclassical production and growth theory. Productivity changes that have been shown to account for a large portion of the overall growth in output must be intimately related to the process of invention, innovation, and diffusion defies explanation within the neoclassical framework. So does the observed heterogeneity in the world with regard to choice of techniques, scale of operations factor proportions, even prices observed across firms, let alone among industries and countries. A full explanation of technological change and growth must certainly involve more than what the comparative statics or neoclassical dynamics can offer.
The theoretical objective of this essay is to construct an analytical model of social change process at the societal level. The societal system analysis developed by Parsons and structural differentiation model developed by Smelser is by its nature an appropriate method for analysing dynamic processes of change in social system. It takes for granted that such phenomena as tensions and disturbances are incorporated in the very processes leading to equilibrium. Thus I think it is useful to borrow the basic framework of Social system analysis and structural differentiation model to build a model for explaining Social change processes and social development stimulated by industrialization. By viewing function as a leading concept this model is able to explain the route through which technological progress affects structural change and the structural changes accompanying industrialization can be viewed as integrated movements toward functional rationalization. The problem of social change arises when the equilibrium conditions, under which the system normally functions, are disturbed. In line with this logic, this paper is organized into five sections as follows:
Objective: To analyze long-term follow-up sonographic findings of intrathyroidal thymus in children. Materials and Methods: Among 1259 patients with congenital hypothyroidism under 15 years of age who underwent thyroid ultrasonography (US), 41 patients were diagnosed with an intrathyroidal thymus based on US criteria, i.e., hypoechoic solid lesion with punctate and linear echogenicity. In 26 patients aged one to 14 years old, the last follow-up US was performed after 6 to 132 months and compared with the initial US. The lesion was considered to decrease in size if there was a change of more than 2 mm in any dimension. The margin change was divided into well-defined and indistinct, blurred. When the echogenicity changed to a hyperechoic from a characteristic thymic echogenicity pattern, the pattern was considered a hyperechogenic. The changes in size were compared with the changes in shape, margin, and echogenicity pattern. The changes in size, shape, margin, and echogenicity were analyzed the association with the age of last follow-up. Statistical analysis was conducted using the chi-squared test and logistic regression. Results: Fifteen (57.7%) cases were stable in size, and 11 (42.3%) decreased in size, including one that disappeared. Ten (38.5%) cases changed to indistinct margins from initially well-defined margins including one case of initially indistinct margin. Six (23.1%) changed to hyperechogenic, from initially characteristic thymic echogenicity patterns. When follow-up change was compared, decreases in size were significantly associated with lesion changes to indistinct margins (p = 0.004). The age at last follow-up was significantly associated with change to hyperechogenicity (odd ratio, 2.141; 95% confidence interval, 1.144–4.010, p = 0.017). Conclusion: On follow-up US, an intrathyroidal thymus may be decreased in size, with indistinct margins, or show changes to a hyperechoic mass. Decreases in size may be associated with changing to indistinct margins, and changes to hyperechogenicity may be associated with increasing age.
This study explores how the COVID-19 pandemic has changed family life and relationships as well as how these changes affect perceived stress among married men and women. This study investigated changes in family time use, household work, child care, leisure activities, income and expenditures along with relationships between spouses and children using a sample of 627 married persons surveyed online from May 19 to 25, 2020. The results showed that the amount of time spent on household work, child care, and family leisure have increased and that the perceived burden of household work and child care has also increased. Gender differences were found in time use, household work, and child care. Leisure activities have changed toward more time watching TV or online media and playing online games and less time on outdoor activities, shopping, and meeting friends. About 38% of respondents reported a reduction in household income and 22% reported an increase in household debt. The majority experienced no change in the quality of relationships with spouses and children, approximately 20% of the sample reported a positive change in relationships with spouses and children. The findings of multivariate regression indicated that change in work time, negative change in household economy, negative change in household work and negative change in relationships with spouses were associated with marital stress. However, this study found that negative changes in child care and in relationships with children did not affect stress among married parents with children in elementary or secondary school.
It has been well known that increased hydrogen ion concentration causes the negative inotropic effect on the heart. But in the status of acid base imbalance, metabolic or respiratory, the question of which status has more profound effect on the cardiac muscle contractility remains unsolved. Furthermore, whether such effect is attributable to the change of the intracellular pH or the extracellular change is a matter of controversy. In many studies concerning to the effect of carbon dioxide tension on the cardiac contractility, the effect of excess oxygen has been ignored despite of its significant influence upon the cellular function. The author intended to investigate the effects of the change of carbon dioxide tension, which causes the pH change simultaneously, as well as the effect of excess oxygen on the cardiac ventricular contractility. Also, to prove which change, metabolic or respiratory, has more profound effect and which change, intracellulcr or extracellular, has more crucial effect, the author examined the contractility of the ventricle under two different conditions. They were as follows: a) PCO_2 was varying despite of same magnitude of the change in pH. b) pH was varying despite of the same magnitude of the change in PCO_2 Turtle hearts were used and the Langendorf preparations were made. The perfusate was Tris-buffer solution for turtle, saturated with various gases, such as air, pure oxygen, nitrogen, or different concentrations of CO_2 balanced with oxygen or nitrogen. The tension and maximal dT/dt were recorded with the Physiograph and its accessories. The results were summarized as follows. 1. The excess oxygen enhanced the ventricular contractility. 2. Increased carbon dioxide tension, which decreases the pH simultaneously, reduced the ventricular contractility and that was more pronounced when CO_2 was balanced with nitrogen gas rather than with oxygen gas. 3. The relationships among several physiological parameters were estimated as follows: a) Y=1.01X-0.56 X: percent change of the tension Y: percent change of maximal contration dT/dt b) Z=1.06X-4.56 Z: percent change of maximal relation dT/dt The corelation coefficient in a) is 0.939 and in b) is 0.926, being significant statistically (P<0.005). 4. When the change of pH were same but the changes of PCO_2 were different, the change of ventricular contractility was more profound in the respiratory decrease of pH, that was higher PCO_2, more depressing effect (P<0.005) was manifested, than in the case of metabolic origin (p<0.005). 5. When the changes of PCO_2 were same but the changes of pH were different, the influence of the latter parameter on the contractility was not significant (P<0.1). From the above results it was suggested that the increased PCO_2, which also causes the decrease of pH, has negative inotropic effect and excess oxygen has positive inotropic effect on the ventricular muscle of the turtle. The negative inotropic effect of the lowered pH on the ventricular muscle was revealed to be more profound when it was induced by respiratory distress rather than motabolic and may be affected by change of intracellular pH rather than extracellular pH.
According to the historical records, though the accurate origins were unknown, the history of Korean "Changs" may date back to about 1200 years ago. The age of early unified Shilla dynasty. The records reveal the first evidence of "Chang"―like soy products in this age. However, since it is generally believed that was imported from China about 2000 years ago, in the beginning of Sam-Kuk-age(三國時期初期) probably "Chang" manufacturing had started earlier. The records on Korean "Changs", however, are available not until the early stage of Yi dynasty. Undoubtedly during these long unrecorded period, the "Changs" manufacturing technology might had developed to certain degrees, since Koreans had been using continuously "Changs" as the basic cereal supplementing foods. But there is noway to know the history. In the records of the early Yi dynasty there appered, for the first time, the separate manufacturing and usage of Toenjang (fermented soybean mash) and Kanjang (soy sauce). Especially the Chinkanjang (陳甘醬―much concentrated or on aged soy sauce including Toenjang within) manufacturing was recorded already. These technology may be undoubtedly the result of long development during the unrecorded period. Later ku-Hwang-Chal-Yo (救荒撮要; a guide book for the relief of farmine) which was published in the age king Myung-Chong (明宗)recorded the various aspects of "Chang" manufacturing technology. According to this book, the "Chang" technology had especially progressed in the age of king Sae-Chong. (世宗). Koreans started to use wheat flour as the raw material of Toenjang meju (메주, soy sauce and soybean mash fermenting startar) in addition to soybean. A new device of expressing of soy sauce from soy sauce waste was also invented at that time. Therefor it can be said that the separate or independent manufacture of Kanjang and Toenjang was Completed in this age. According to the Sa-Si-Chan-Yo (四時纂要; a monthly farm guide) which was published in the year of king Hyo-Chong(孝宗) the "Changs" manufacturing had became one of the annual practices of Korean family and various kinds of characteristic "Changs" Kae-Chang (蟹醬), Jup-Chang (汁醬), Po-Chang (泡醬) were listed as the popular "Changs" at that times. Probably the fundamental technologies of many specific "Changs" manufacturing had been gradually established from the begining of the Yi dynasty to this age together with the development of food substitutes. A large modification in "Chang" manufacturing technology was brought in the middle ages of Yi dynasty. According to San-Lim-Kyung-Chai(山林經濟; a scientific encyclopedia) Chung-Chang (汁醬; the same as Kanjang) and Toenjang were described as the general purpose "Chang" of daily use and Jup-Chang (汁醬), Chung-Kuk-Chang (淸國醬) and Tam-Su-Chang (淡水醬) were listed as the popular specific "Changs" at that time. A new specific "Chang", Man-Cho-Chang (蠻椒醬, red pepper sauce) was deviced also in this age. Amang them the Chung-Chang is basically similar to the Present type of Korean Kanjang. It was described to be prepared entirely from soybean and Toenjang was the by-product of soy-souce, Undoubtedly the Present Korean Kanjang manufacturing technology may derive its origin to this Chung-Chang, using entirely soybean as the sole raw material. Probably further minor modifications, continued to improve "Chang" manufacturing technology and to adapt for home making method and scale, but essentially the similar "Chang" products which originated in the middle ages of Yi dynasty were conveyed to the present. Thus we can list the present day "Changs" as follows.; Chung-Chang, Toenjang, Nam-Cho-Chang (the same as Man-Cho-Chang) Jup-Chang, Chung-Kuk-Chang, Tam-Su-Chang. Among them the Chung-Chang and Nam-Cho-Chang are the only products of extensive general use by Korean of the Present day and others are only for occasional uses for an epicurism etc. The manufacturing procedures of present Korean Kanjang and Toenjang consist of three major steps; that is, the preparation of Meju, Kanjang fermentation, and expressing of sauce. The history of development of these three Kanjang manufacturing procedures are as the follows. I) The history of Kanjang-Meju Preparation method- The first record of Meju is found is San-Lim-Kyung-Jai. In this text it was described as: Cooked soy beans were mashed and made into small clumps and they were left in the room covered with brossonetia leaves, straw, grass leaves or morus bombysis leaves: Probably for microorganisms grow. From the middle ages Yi dynasty the Mejus were left piled in straw woven bages. The present day method, hanging the Mejus under the ceiling with straw ropes in the room, had been already described in the above San-Lim-Kyung-Jai also. It had been generally recogniged in the old texts of agriculture that coverage of Meju by yellow molds (黃衣) yielded good results. Without the present knowledge of pure culture technique of microbiology, it might hardly be expected to have a good growth of yellow molds by such primitive methods of Meju preparation, we can imagine. Probably such conditions rather might had favored the growth of bacteria and making Meju to Natto type soy product. We can think only of the effect of grass coverage on a good growth of yellow molds. There appeared many other very specific methods of Meju preparations described in the old texts, but none of them survived to be practiced and accepted among Koreans until to the present day. 2) The history of Kanjang fermentation- Until the middle age of Yi-dynasty Chin-Kanjang fermentation method which had been a device chiefly to obtain much concentrated soysauce so that it used small quantities of brine compared to the amount of Meju had been practiced. Later the tendency had come to obtain more quantities of dilute soy sauce and from the end of Yi dynasty the present day Chung-Chang fermentation method had emerged. This method has been using Meju: salt: water in the quantity ratio of 1 : 1 : 4. 3) History of method of expressing soy sauce- In the beginning the soy sauce had not been expressed from soybean mash but the whole mixtures had been consumed as "Chang". From the beginning of Yi dynasty as the need of soy sauce alone had become large the expressing method started to develope. In Ku-Hwang-Chal-Yo expressing by wood curtain was already described. In the middle ages of Yi dynasty, a hole was made in "Chang" and sauce exeeded in the hole was scooped out, or Yong-Su (a bamboo woven basket) were used to separate soy sauce from "Chang". From the end of Yi dynasty the present filtration method (for ex. using sive) were started to be used.
In internal Diesel combustion engine, The change of air temperature is change the density of air in the stoke volume to Diesel engine. The influence of power and efficiency is change according to the atmosphere- temperature of air. For calculating, decided the Diesel engine scale is 2000cc and 4cylinders mechanical compression ratio is 18 of Diesel engine. Our country, Atmosphere-temperature change is -20℃ in winter to 40℃ in summer. The density of air increase by the temperature drop and decrease by the temperature rises. Density change of air is appear mass change to the stroke volume in Diesel engine. The mass change is change the compression ratio of Diesel. engine. The compression ratio change is change the thermal efficiency and power of Diesel engine. In atmosphere-temperature -20℃, Compression ratio change 20.687 and thermal efficiency change 66.05%. In atmosphere-temperature 40℃, Compression ratio change 16.913 and thermal efficiency change 63.21%. The Compression ratio and thermal efficiency are increase to the low temperature. The results are as follows, 1. The change of atmosphere temperature is change the density and mass of air and influence the power and thermal efficiency to the Diesel engine. 2. For increasing the mass of intake air to influenced the power and thermal efficiency must be drop the temperature of intake air 3. For drop the temperature of intake air, intake manifold must be set ahead of engine and order side of exhaust manifold.
Climate change has become a megatrend that will lead to significant changes in future society. Korean and overseas agencies specializing in climate forecasts predict that average global temperatures will continue to rise. While climate change may potentially have certain positive impacts for crop yields, the overall impact is predicted to be negative for environment and food security. In this context, our study aims to suggest a plan for systematically establishing a stable food supply system in Korea in respose to climate change. Various analytical models were employed, including: a response analysis based on questionnaire for farmers, panel-based analysis of the causes of pests and diseases in rice production, a random-effects model for panel data of extreme weather impact, and an analysis of food supply effects using the Simulation Model for Climate-Agriculture Relations (SIMCAR) integrated model in conjunction with the Crop Estimation through Resource and Environment Synthesis (CERES) model of the Korea Agricultural Simulation Model (KASMO). An analysis was made of major grain yields by means of the KREI-KASMO. This revealed reduced yields and area in comparison with the baseline in 2050, resulting in a reduction of rice production by 17.8%p in the RCP8.5 scenario, and reduction of soybean by 21.2%p and reduction of barley by 13.7%p in the A2 scenario. Self-sufficiency ratio of major grains in 2050 drawn from the SIMCAR revealed that the climate change scenario for rice showed 55.0% to be reduced by 18.3% in comparison with the baseline. It is predicted that selfsufficiency ratio in rice will drop to 50% which means a half of consumed rice should be imported. Key tasks for building a stable food supply system to cope with climate change were developed based on the domestic production capacity, the buffering capacity to climate change, import capacity from other countries, and policy performance capacity with reference to the empirical analysis. First, the suggested key tasks for improving the domestic production capacity include developing and disseminating adaptation technology, conserving farmland and expanding arable land, practicing climate-smart agriculture by using fusion technology, and modernizing infrastructure for agriculture. Second, key tasks for improving buffering capacity to climate change are improving resilience and biodiversity, building a risk management system, and further improving storage of food in Korea and other countries. Third, major tasks for improving the import capacity from other countries are constructing overseas food bases, effectively using the international grain market, and enhancing international cooperation with relevant countries. Finally, key tasks for improving policy performance capacity are refining and applying the climate change impact analysis model with respect to policies, expanding investments in research and development, building a vulnerability assessment system, enhancing education and training, and installing Climate Change Response Center for Agriculture (tentative). In this study, several key challenges were presented in the four different areas related to building a stable food supply system which can help overcome the challenges of climate change. It is expected that the nature of the policies that need to be prioritized and promoted, given the constraints of budget, organization and information will be addressed in future research. Also, in order for the solutions for key challenges to work properly in the field such that policy outcomes will be maximized, a consortium of research bodies in the related fields of agriculture, agricultural meteorology and agricultural economics should be created. As preparation for specific action programs. Furthermore, follow-up studies should be conducted to verify the expenses required for developing reliable climate change impact assessment models and the effectiveness of the enforced policies. Such fie
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The purpose of this study was to evaluate the postoperative stability of the severe open bite or mandibular prognathic patients after mandibular set back surgery by Obwegeser II method. There were 19 patients who had been undergone Obwegeser II method. The horizontal and vertical position of the cephalometric points were measured preoperation and immediate postoperation, postoperative 1 month, postoperative 6 months ; were analyzed by linear measurement to evaluate changes in skeletal landmark and the relapse was compared between open bite group and prognathism group. By the operation, horizontal change of B was 6.84±4.35mm and vertical change of B was 6.28±3.25mm in open bite group and horizontal change of B was 14.20±4.81mm and vertical change of B was 1.99±2.66mm in prognathism group, horizontal change of Pog was 3.82±5.71mm and vertical change of Pog was 5.38±2.11mm in open bite group and horizontal change of Pog was 13.24± 5.99mm and vertical change of Pog was 1.91±0.94mm in prognathism group. Between immediate postoperation and postoperative 1 month, all skeletal landmarks change was no statistical difference (p>0.05) and there were no statistical difference between open bite group and prognathism group except x-Me landmark (p>0.05). Between postoperative 1 month and 6 months, horizontal change of B was 0.12±1.35mm and vertical change of B was 1.47±1.48mm in open bite group and horizontal change of B was 1.43±1.35mm and vertical change of B was 0.82±1.99mm in prognathism group, horizontal change of Pog was 0.13±1.40mm and vertical change of Pog was 0.88±1.71mm in open bite group and horizontal change of Pog was 1.08±1.74mm and vertical change of Pog was 0.47±1.57mm in prognathism group (p>0.05) and there were no statistical difference between open bite group and prognathism group (p>0.05). Between immediate postoperation and postoperative 6months, horizontal change of B was 0.24±1.17mm and vertical change of B was 1.87±1.63mm in open bite group and horizontal change of B was 1.54±1.55mm and vertical change of B was 1.04±1.96mm in prognathism group, horizontal change of Pog was 0.91±1.46mm and vertical change of Pog was 1.18±2.05mm in open bite group and horizontal change of Pog was 0.96±1.62mm and vertical change of Pog was 1.23±2.35mm in prognathism group (p>0.05) and there were statistical difference between open bite group and prognathism group in x-B, x-Pog, x-Gn, x-Me (p<0.05). Obwegeser II method is considered as one of the best operation when surgical correction of severe open bite or severe mandibular prognathism is needed.