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송재두 청주대학교 융합신기술대학원 2022 국내석사
2차원 평면상에서의 교통정체의 문제를 해결하고, 도심에서의 소음공해와 대기오염문제를 해결하기 위한 방안으로 도심항공모빌리티(UAM)가 제시되고 있다. UAM에 대한 수요와 공급은 증가할 것으로 예견되고 있지만, 기체를 개발 중인 회사별로 모양과 형태가 각각 다르다. 따라서 각 UAM에 대한 운용효율성을 분석하여 이를 비교하는 것이 현 시점에서 매우 필요하다. 이러한 비교분석을 통하여 생산을 시작하는 단계와 부품의 공급이 활성화되어 있는 장기적인 양산 시점에 있어서 어떠한 형태의 기체를 사용하는 것이 적절한지 확인할 수 있다. 운행거리별 소요에너지와 운행시간당 소요에너지를 계산함으로써 각 기체들의 운행효율성을 비교해 볼 수 있다. 분석결과를 통하여 운항목적에 알맞은 기체를 선정할 수 있을 것이다. 생산의 초기단계에 있어서는 Wisk Cora와 Lilium Jet가 가장 효율성이 뛰어나지만, 좌석당 기체비용과 운행비용을 고려하여 분석을 실시한 결과 Wisk Cora와 Lilium Jet에 더하여 Joby S4가 가장 뛰어난 효율성을 보인다. 생산의 초기단계에 있어서는 Lift & Cruise type와 Vectored Thrust형태의 기체가 효율성에 있어서 큰 차이를 보이지 않는다는 것을 확인할 수 있다. 생산을 시작한지 5년이 경과하여 장기적인 양산의 시기의 접어들게 되면 UAM의 형태별로 효율성에 변화가 발견된다. 좌석당 기체비용과 운행비용을 고려하여 분석을 실시한 결과 Joby S4와 Lilium Jet가 가장 효율적인 기체인 것을 확인할 수 있다. 그리고 그 뒤를 Wisk Cora가 뒤따르고 있다. 결국 UAM의 생산이 본격적으로 진행이 되어서 생산이 활성화되면 Vectored Thrust형태의 기체가 가장 효율적인 기체가 된다는 것을 알 수 있다. 도심항공모빌리티는 도심에서 이착륙을 하고 도심에서 많이 운행된다. 따라서 노선을 운용하는 버스나 지하철과 같은 운행방식을 따를 수도 있고, 택시와 같이 승객의 요구에 의해 운행하는 방식을 따를 수도 있다. 단거리위주와 승객의 요구에 의한 운행을 고려한다면 멀티콥터형태의 UAM이 효율적이다. 노선을 따라 운용하거나 여러 정거장을 거치면서 운용을 해야 한다면 Lift and Cruise와 Vectored Thrust형태의 기체가 더욱 효율적으로 사용될 것이다. 그러나, 생산이 매우 활성화되어 장기적인 양산단계에 접어들게 되면 효율성에 의거하여 Vectored Thrust형태의 기체가 더욱 사용될 것으로 보인다. To properly resolve the traffic jam at two dimensions, noise at urban area and air pollution, Urban Aerial Mobility is proposed as a solution. The increase of demand and supply of UAM is foreseen as a result, but the type of vehicles is so different among manufacturers. Operational efficiencies of each UAMs should be analyzed, and the empirical result would be relevant at present. It can be verified which type of vehicle is more properly used at initial stage, or which type in long term when the production industry is vitalized. Energy consumption and flight time of each UAMs can be measured to compare the operational efficiencies by flight distances. Under analytical results, a proper UAM can be selected according to a specific operational purpose. Wisk Cora and Lilium Jet show best efficiency at initial stage when vehicle cost and operational cost are calculated. Joby S4, however, is added to the most efficient UAM group when vehicle cost and operational cost per a seat are calculated. As a whole, at initial production stage, there is no big efficiency difference between Lift & Cruise type and Vectored Thrust type UAMS. In the long term or near term production stage, after five years of beginning initial production stage, some changes are shown at UAMs’ efficiency. Joby S4 and Lilium Jet show best efficiency when vehicle cost and operational cost per a seat are calculated, and they are followed by Wisk Cora. After all, after UAM production chain is vitalized and UAM is widely used, the Vectored Thrust type UAM becomes most efficient vehicle. UAM should take off and land at urban area, and it also should be operated at urban area. The way of flight operations can be similar to that of bus and train as a commuting vehicle, or it can be similar to that of taxi as an on-demand vehicle. Efficiency of multi-rotor type UAM is better than other type when it is used as an on-demand and short-haul vehicle. Efficiency, however, of Lift & Cruise and Vectored Thrust type is more appropriate as a commuting vehicle which stops by several vertiports. Vectored Thrust type UAM, in the long term, can be usable more widely, owing to better operational efficiency.
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Ⅰ. Introduction After China started to induce foreign capital in earnest, a lot of foreign firms have invested their capital. And also, Korean firms have paid attention to Chinese market and considered it to be promising to invest. It is necessary, therefore, for us to investigate the Chinese investment climate and the factors which induce foreign capital. The goal of this analysis is to contribute to enlarging Korean investment in China. To get the goal, this paper extracts some factors helping China to induce foreign capital. Multiple regression method is used as one of the analytical tools, and the other is factor analysis. Ⅱ. Theoretical Study on Foreign Direct Investment & Precedents for Empirical Analysis The FDI (Foreign Direct Investment) before the late 1960's consists mainly of the one by the developed countries. Developing countries are ,however, expanding their investment abroad nowadays. So, the theories explaining only the investment by the developed countries - or by the multinational firms of those - can not be the general one. The eclectic theory is considered to be explaining the investment by the countries at every level. To select the variables to be used in the empirical study, this paper consults some precedents for empirical analysis. Ⅲ. Investment Environment in China & The Satus Quo of Investment from Abroad China have established many laws and fixed them up to induce more foreign capital. Providing and reorganizing the system can not be excluded. Thanks to the above exertions, China have induced more and more foreign capital especially in the fields of manufacturing industry and the sum total. Ⅳ. Empirical Analysis The methodology can be divided into two main parts, each being designed according to the analytical method described in chapter Ⅰ. In the first part, the original variables are extracted and then concerntrated into 4 independent variables (factors) by means of factor analysis. In the second part, a series of multiple regression analysis is conducted to discover the significant factor associated with the foreign investment inflow. The basis framework of this empirical study is presented as follows. ◁그림 삽입▷ (원문을 참조하세요) Ⅴ. Conclusion The results of this study present that the most powerfully attractive factor for foreign investors is economic development level, in case of China. In addition to the above factor, there is other less important one that is also found positively related to foreign direct investment. It is the latent force for development. Finally, these results suggest two facts. The one is that foreign investors are not easily impressed by short-run variables in the environmental factors. The other is that location specific variables should be considered seriously in setting-up the investment strategy for China.
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