• International Journal of Air-Conditioning and Refrigeration
• /
• 제8권1호
• /
• pp.50-61
• /
• 2000

The effects of an inserted coil on flow . patterns and heat transfer performance for a horizontal rotating heat pipe have been studied experimentally. Especially, the present study is to see an internally inserted helical coil inside a RHP would lead to the same kind of results as internal fins. Visualization test conducted for an acryl tube, charged water with at a volumetric rate of 20%. When the flow kept pool regime at a low rpm(less than 1,000rpm), the movement of coil forced the water to flow in axial direction. But this pumping effect of coil disappeared, when the pool regime changed to annular one which could be created by increasing rpm. The pumping effects for RHP with an inserted coil resulted in the enhancement in both condensation heat transfer coefficient and heat transport limitation, as obtained in case of using internal fins. But all these effects became negligible in the range of higher rpm(above 1,000-1,200) with the transition of flow regime to annular flow.

• International Journal of Air-Conditioning and Refrigeration
• /
• 제12권2호
• /
• pp.79-86
• /
• 2004

An analytical and experimental study has been conducted to determine the optimal charging mass of working fluid for the maximum heat transport capacity of heat pipe with axially grooved wick. When the heat pipe is operated in a steady state, the liquid-vapor meniscus recession of working fluid to the bottom of groove is occurred in the evaporator region. In this work, the optimal charging mass of working fluid was obtained by considering the meniscus recession from the axial variation of capillary pressure, the radius of curvature and wetting angle of meniscus of liquid-vapor interface. Experimental results were also obtained by varying the charging mass of working fluid within a heat pipe, and presented for the trend of maximum heat transport capacity corresponding to the operating temperature and the elevation of heat pipe. Finally, the analytical results of the optimal charging mass of working fluid were compared with those from the experiment, both of which were in good agreement with each other.

• 한국항공운항학회지
• /
• 제27권1호
• /
• pp.57-68
• /
• 2019

The emission trading system implemented in Korea is a system in which the government allocates or sells emission rights by setting the emission allowable amount to economic players subject to the emission trading system, allowing companies to freely trade shortfall or extra money through the emission trading market. Korea also had implemented its first emission trading system scheme period of time from 2015 to 2017. As a result of the first planning period in which total of seven Korean airlines were targeted, the emission amount was about 5.51 million KAU, while the quota amount was only about 4.85 million KAU, about 116% of the actual quota was emitted and Domestic airlines have incurred additional costs of about 10.7 billion won. Due to ICAO's implementation of CORSIA, the airlines are expected to have to shoulder additional costs because purchasing exceed quota will be increased in order to offset excess emissions not only on domestic but also on international routes. Thus, this paper had analyzed the characteristics of the carbon trading system of air transport industry and suggested a mix of regulatory policies as an improvement method.

• 융합경영연구
• /
• 제9권3호
• /
• pp.11-21
• /
• 2021

Purpose: The purpose of this study is to understand the status quo of production efficiency in private industrial enterprises above designated scale in China's 31 provinces (including municipalities directly under the central government, autonomous regions) (hereinafter referred to as China's 31 provinces). Research design, data and methodology: Find out the factors affecting the development of production efficiency in private industrial enterprises, using DEA, Data Envelopment Analysis and Malmquist index analysis, build the evaluation model of production efficiency in private industrial enterprises, and analyze the data of China's 31 provinces private industrial enterprises in 2015-2019. Results: The research results show that the production efficiency of private industrial enterprises in China is improving on the whole. Although the total factor productivity has decreased slightly, the overall efficiency and pure technical efficiency have increased significantly. Conclusions: The conclusion of this study can provide reference for Chinese private industrial enterprises to improve production efficiency and make development plan. The limitation of this paper lies in the fact that the private industrial enterprises in inefficient provinces have not been given specific improvement plans.

• International journal of advanced smart convergence
• /
• 제11권2호
• /
• pp.153-162
• /
• 2022

The impact of the information technology industry on economic development is becoming increasingly important. In this study, we take China's provincial-level regions from 2015 to 2020 as the research object, comprehensively evaluates the level of their information technology systems by the entropy weight method, and then measures the coupling coordination relationship between the information technology system and the economic development system by the coupling coordination degree model. As a result, we found that the income of the information technology industry, the investment of talents and science research have the most important influence on the level of the information technology system. During the research period, with increasing values, the coupling degree of the two systems was at a high level. Affected by development strategies, diffusion effects and industrial relocation, the coupling degree in the central and western regions has shown a rapid growth trend. The coordination degree of the two systems is relatively low, and 83.9% of the provinces are in the medium-low coordination stage. The information technology industry has obviously promoted economic development. Besides, relevant policies should be introduced to effectively support and guide the high-quality development of the information technology industry and promote the high-level coordinated development of the two systems.

• 항공우주정책ㆍ법학회지
• /
• 제31권2호
• /
• pp.99-143
• /
• 2016

General aviation and air transport are two wings of the civil aviation industry. Chinese air transport is developing rapidly, and has become the world second air transport system only second to US since 2005. However, Chinese civil aviation is far behind the world average level, and cannot meet requirements of economic construction and social development. The transition and structural adjustment of Chinese economy provide the general aviation with a unprecedented broad market. The prospect of general aviation is promising and anticipated. The development of general aviation industry needs the legislative supports, and the current legislative conditions of Chinese general aviation are undoubtedly far behind the realistic requirements. Accelerating the legislation in Chinese general aviation industry requires scientific legislation concept. First, Legislation must promote development of general aviation industry. The general aviation will serves as a Chinese emerging industry that boosts domestic demand, promotes employment and expedite domestic economic development. We should, based on both the concept of promoting the industrial development of general aviation and national industrial planning, enact and rectify relative laws and regulations. And we should also straighten out the relationship between aviation security and industrial development and promote the revolution of low-altitude airspace management in an all-round way, in order to improve the utilization rate of airspace resources, classify and establish airspace, simplify examination and approval procedure and intensify operation management. In addition, what we should do is to expedite the infrastructure layout construction, guide the differentiated but coordinated development of general aviation industries in various areas, establish a united supervision mechanism of general aviation, redistrict the responsibilities of Chinese Air Control Agency and set up legislation, law enforcement and judicial systems with clarified institutions, clear positioning and classified responsibilities, so as to usher in a new era of the legislative management of Chinese general aviation industry. Second, shift the focus from regulations to both regulations and services. Considering the particularity of the general aviation, we should use American practices for reference and take into account both regulation and service functions when enacting general aviation laws. For example, we should reduce administrative licensing and market supervision, and adopt "criteria" and "approval" management systems for non-commercial and commercial aviation. Furthermore, pay attention to social benefits. Complete social rescuing mechanism through legislation. It should be clarified in legislation that general aviation operators should take the responsibilities of, and ensure to realize social benefits of environmental protection and ecological balance .Finally, rise in line with international standards. Modify Chinese regulations which is inconsistent with international ones to remove barriers to international cooperation. Specify basic legislative principles. One is the principle of coordination. Realize coordination between the civil aviation and general aviation, between military aviation and civil aviation, and among departments. Two is the principle of pertinence. The general aviation has its own rules and specialties, needing to be standardized using specialized laws and regulations. Three is the principle of efficiency. To realize time and space values of general aviation, we should complete rules in aerospace openness, general aviation airport construction, general aviation operations, and regulation enforcement. Four is the principle of security. Balance the maximum use of resources of Chinese airspace and the according potential threats to Chinese national interests and social security, and establish a complete insurance system which functions as security defense and indemnificatory measure. Establish a unified legal system. Currently, the system of Chinese general aviation laws consists of national legislation, administrative laws and regulations and civil aviation regulations (CAR). Some problems exist in three components of the system, including too general content, unclear guarantee measures, incomplete implementation details, and lacking corresponding pertinence and flexibility required by general aviation regulations, stringency of operation management and standards, and uniformity of standards. A law and regulation system, centered on laws and consisting of administrative laws regulations, industrial regulations, implementation details, industrial policies and local laws and regulations, should be established. It is suggested to modify the Civil Aviation Law to make general aviation laws complete, enact the Regulations of General Aviation Development, and accelerate the establishment, modification and abolition of Chinese general aviation laws to intensify the coordination and uniformity of regulations.

• 항공우주정책ㆍ법학회지
• /
• 제1권
• /
• pp.193-222
• /
• 1989

The purpose of this study is to review the rights and duties of cargo owners, the party to the contract of international carriage of goods by air under the Warsaw Convention System and the IATA conditions. It is generally known that air freight is the most-cost mode of transportation. However, should there be considerations of total distribution cost, the use of air freight leads exporters to be advantageous in physical distribution. The Warsaw Convention System defined and limited the rights and duties of cargo owners and air carriers paticipating in the international carriage of goods, but it does not regulate every aspect of air transportation. Therefore, the unregulated parts are governed by national laws and by individual contracts of carriage. The International Air Transport Association(lATA), a worldwide organization of airlines, has formulated model conditions of contract for the carriage of cargo. These models are not uniformly followed but they serve as a basis for many of the individual standard form of contracts prepared by air carriers. The contract of air carriage of goods is a contract of adhesion, 'the consignor recognizing and accepting the conditions laid down by the carrier'. There are consignors and carriers as the parties to the contract of international carriage of goods. In addition to his basic right, implied in Warsaw Convention Article 18 and 19, to require devery of the goods in good condition and at the date agreed upon, the consignor has the right to dispose the goods in the course of the journey up to the moment when the consignee is entitled to require delivery. If it is impossible to carry out the orders of the consignor, the carrier must so inform him forthwith. The right conferred on the consignor ceases at the moment when that of the consignee begins in accordance with Warsaw Convention Article 13. Nevertheless, if the consignee declines to accept the air waybill or the goods, or if he cannot be communicated with, the consignor resumes his right of disposition. Unless it is otherwise agreed, it is the duty of the carrier to give notice to the consignee as soon as the goods arrive. The consignee is entitled, on arrival of the goods at the place of destination, to require the carrier to hand over to him the air waybill and to deliver the goods to him, on payment of the charges due and on complying with the conditions of carriage set out in the air waybill. The air waybill is supposed to be made out by the consignor. If the carrier makes it out, he is deemed, subject to proof to the contrary, to have done so on behalf of the consignor, whether there is one air waybill or several, each must be made out in three original parts. The first is for the carrier, the second is for the consignee, and the the third is handed to the consignor when the shipment has been accepted. The consignor is responsible for the correctness of the particulars and statement concerning the cargo appearing in the air waybill. Each of the original parts of the air waybill has evidential value and possession of his part is a condition for the exercise by the consignor or consignee of his rights under the contract of carriage. Hague Protocol set forth in Article 9 that nothing in this. Convention prevents the issue of a negotiable air waybill, but Montreal Additional Protocol No. 4 deleted this article. All charges applicable to a shipment are payable in cash at the time of acceptance thereof by the carrier in case of a prepaid shipment or at the time of delivery thereof by the carrier in case of a collect shipment. The carrier shall have lien the cargo for unpaid charges and, in the event of non-payment thereof, shall have the right to dispose of the cargo at public or private sale and pay itself out of the proceeds of such sale any and all such amounts. In conclusion, the Warsaw Convention System has the character of ambiguity in various respects, not only in the part of the forms of documents but also in conditions of contract. Accordingly, the following propositions might be considered: (1) If the carrier does not obey the orders of the consignor for the disposition of the goods without proper reasons, he will be liable strictly for any damage which may be caused thereby to the cargo owner. The special agreement and carrier's conditions of carriage which limit unreasonably the consignor's right of disposition of the goods will be nullified. (2) The instrument of the Warsaw Convention System which is not yet in force(Montreal Additional Protocol No. 4) would considerably simplfy the processing and keeping of computerized records of the carriage. Until this instrument enters into force, the airlines will be faced with practical problems preventing them to substitute computerized data processing techniques for the formal issuance of the documents. Accordingly, Montreal Additional Protocol No. 4 should become effective as soon as posisble. From a practical point of view in the international trade, the issuance of negotiable air waybill should be permitted for the security of the bank.

• 한국환경과학회지
• /
• 제11권6호
• /
• pp.507-517
• /
• 2002

Cheeka Peak is a unique site for monitoring the background chemistry and aerosol contents of pristine marine air at mid-latitude. During long-range onshore winds that occur frequently throughout the year, it is predicted to have the cleanest air in the northern hemisphere. Measurements of CO and O$_3$were conducted at Cheeka Peak Observatory(CPO) on the northwestern tip of Washington state, USA during March 6 ∼May 29, 2001. The data have been segregated to quantify the mixing ratio of these species in the Pacific marine atmosphere. Also the marine air masses were further classified into four categories based on 10-day backward isentropic trajectories; high, mid, and low latitude and those which had crossed over the Asian industrial region. The diurnal variation of CO and O$_3$at CPO showed a similar to tendency of background measurement site. When marine air mass flowed to CPO, CO concentration was lower and O$_3$was similar or higher than those of total data. The westerly flow from ocean, not easterly from continent occurred the high concentration of CO and O$_3$at CPO. Using the trajectory segregation of marine air mass, the comparison of concentration according to latitude calculated. the CO concentration of Asian trajectory was lower than other latitudes, O$_3$concentration was higher.

• 항공우주정책ㆍ법학회지
• /
• 제25권2호
• /
• pp.139-162
• /
• 2010

국제운송에 있어서 항공자유화 정책(open skies police)은 하늘의 자유 또는 하늘의 개방이란 의미를 내포하고 있다. 규범적으로 여러 형태의 운송권을 타 국가에 허용하는 개방 정책이나 국제 항공운송에 있어서 자유경쟁 정책이다. 미국의 경우, 1978년 항공규제완화 이후 경쟁력을 갖춘 대형 항공사들이 시장 기회가 많은 국제 항공시장에서 경쟁할 수 있도록 하기위해 네델란드와 항공자유화 협정을 체결한 것을 시작으로 많은 국가들이 항공자 유화 협정을 맺고 있으며, 우리나라의 경우는 20여개국과 항공자유화 협정을 체결하고 있는 상태이다. 상용고객우대제도(Frequent Flyer Program : FFP)는 미국 정부의 항공법 규제 완화 이후 항공 운임 전략의 일환으로 포괄적 마케팅 제휴의 한 부분이다. 자사 항공편을 이용하는 고객을 회원제로 관리하는 제도로서, 승객들의 탑승이나 기타 이용 실적에 따라 마일리지를 부여하여 누적된 마일리지가 일정한 기준에 도달하면 다양한 유형적 보상을 실시하는 개념이다. 상용고객 우대제도는 초창기에는 고객확보를 위한 마케팅 중심으로 형성되었으나, 항공사간의 치열한 경쟁으로 인해 경영이 점점 더 어려워지고 있는 상황에서 항공사들은 상용고객우대제도를 항공사 경영성과를 높이는 마케팅의 중요한 전략의 수단으로 활용하고 있다. 따라서 항공사들은 충성고객을 확보하기 위해 고객의 니즈를 효과적으로 파악할 필요가 있다고 판단한다. 항공사 상용고객우대제도에 따른 성과가 국제 경쟁에 미치는 영향은 다양하게 나타날 수 있다. 첫째, 노선망을 확대를 통해 항공 시장을 확보할 수 있다. 둘째, 운항빈도를 증대시킴에 따라 고객에게 항공 상품의 공급 능력을 증대시키게 될 수 있을 것이다. 셋째, 새로운 시장에 우선적으로 진입함으로써 경쟁 항공사를 견제하는 효과가 나타날 것 이라고 생각한다. 그럼에도 불구하고 항공사 상용고객우대제도에 대한 실증적 연구는 매우 미비하다. 따라서 본 연구에서는 상용고객우대제도의 전략적 제휴 유형을 검토한 후 이의 제휴 성과와 국제경쟁에 미치는 영향을 알아보고자 한다. 주요 국가들의 항공사 전략적 제휴는 항공자유화 정책상 세계적인 추세이다. 우리나라의 경우에도 국적 항공사들의 발전과 경쟁력 확보를 위해서는 보다 더 현실적인 항공자유화 협정이 진행되어야 할 것이다. 본 논문은 항공자유화 정책 상 항공사 상용고객우대제도의 제휴 성과와 국제경쟁에 관한 연구이다. 본 연구에서는 5개 글로벌 제휴 그룹(star, oneworld, wings, qualiflyer, skyteam)을 대상으로 선정하여 제휴 그룹의 항공사가 보유한 자원구조와 정보기술수준이 제휴 유형에 미치는 성과에 대한 실증 연구를 실시하고자 하였으며 가설 검정을 위해 일원분산분석과 회귀분석을 사용하였다. 규모가 큰 대형항공사 이거나 중소 규모의 지역 항공사일지라도 세계적인 네트워크 와 조직력을 갖춘 제휴 그룹에 참여하는 항공사는 높은 성과와 국제 경쟁력을 확보할 수 있다고 판단한다. 항공사 승객의 경우, 회원 가입항공사의 호텔과 렌트카, 면세점, 여행사 등의 제휴 네트워크를 활용하여 항공사 탑승 이외의 마일리지 획득하는 것외에도 관련된 서비스 혜택에 대한 관심과 선호도가 높으므로, 우리나라의 항공사들은 항공사간 제휴뿐 만 아니라 호텔 등 타 산업과의 다각적으로 제휴를 통해 공격적 마케팅을 실행해야 한다.

• 한국환경과학회지
• /
• 제5권3호
• /
• pp.277-284
• /
• 1996

The Characteristics of atmospheric flow and dispersion of air pollutants in the mountainous coastal area were studied using two-dimensional model by the combination of land-sea breezes and transport. The pollutants emitted into the simulated wind field in considering with the mesoscale local circulations. The typical effects of land-sea breezes and tophography of coastal area on the dispersion are discussed in detail, and the model is proved as an useful tool to pridict real time pollutant transport by the results of application studies in Pusan, Korea where the urbanized coastal area with mountainous topography. It was found that sulfur dioxide ($SO_2$) are differently transported and concentrated as going inland by the influence of the sea breeze with topographic changes. Key words : land-sea breezes, sulfur dioxide, dispersion, coastal area.