• Aerospace Engineering and Technology
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• v.8 no.1
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• pp.144-153
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• 2009

To study the plume effects in the rarefied region, the Direct Simulation Monte Carlo(DSMC) method is usually adopted because the plume field usually contains the entire range of flow regime from the near-continuum in the vicinity of nozzle exit through transitional state to free molecular at far field region from the nozzle. The objective of this study is to investigate the behaviors of a small monopropellant thruster plume in the rarefied region numerically using DSMC method. To deduce accurate results efficiently, the preconditioned scheme is introduced to calculate continuum flow fields inside thruster to predict nozzle exit properties used for inlet conditions of DSMC method. By combining these two methods, the rarefied flow characteristics of plume such as strong nonequilibrium near nozzle exit, large back flow region, etc, can be investigated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.9
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• pp.906-915
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• 2009

To study the plume effects in the vacuum area, the Direct Simulation Monte Carlo(DSMC) method is usually adopted because the plume field usually contains the entire range of flow regime from the near-continuum in the vicinity of nozzle exit through transitional state to free molecular at far field region from the nozzle. The objective of this study is to investigate the behaviors of a small monopropellant thruster plume in the vacuum area numerically using DSMC method. To deduce accurate results efficiently, the preconditioned scheme is introduced to calculate continuum flow fields inside thruster to predict nozzle exit properties used for inlet conditions of DSMC method. By combining these two methods, the vacuum flow characteristics of plume such as strong nonequilibrium near nozzle exit, large back flow area, etc, can be investigated.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.2
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• pp.345-366
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• 2018

Article 37 of the International Convention on Civil Aviation requires that rules should be adopted to keep in compliance with international standards and recommended practices established by ICAO. As SARPs are revised annually, each ICAO Member State needs to reflect the new content in its national aviation Acts in a timely manner. In recent years, data-driven international standards have been developed because of the important roles of aviation safety data and information-based legislation in accident prevention based on human factors. The Safety Management System and crew Fatigue Risk Management Systems were reviewed as examples of the result of data-driven rulemaking. The safety management system was adopted in 2013 with the introduction of Annex 19 and Chapter 5 of the relevant manual describes safety data collection and analysis systems. Through analysis of safety data and information, decision makers can make informed data-driven decisions. The Republic of Korea introduced Safety Management System in accordance with Article 58 of the Aviation Safety Act for all airlines, maintenance companies, and airport corporations. To support the SMS, both mandatory reporting and voluntary safety reporting systems need to be in place. Up until now, the standard of administrative penal dispensation for violations of the safety management system has been very weak. Various regulations have been developed and implemented in the United States and Europe for the proper legislation of the safety management system. In the wake of the crash of the Colgan aircraft, the US Aviation Safety Committee recommended the US Federal Aviation Administration to establish a system that can identify and manage pilot fatigue hazards. In 2010, a notice of proposed rulemaking was issued by the Federal Aviation Administration and in 2011, the final rule was passed. The legislation was applied to help differentiate risk based on flight according to factors such as the pilot's duty starting time, the availability of the auxiliary crew, and the class of the rest facility. Numerous amounts data and information were analyzed during the rulemaking process, and reflected in the resultant regulations. A cost-benefit analysis, based on the data of the previous 10 year period, was conducted before the final legislation was reached and it was concluded that the cost benefits are positive. The Republic of Korea also currently has a clause on aviation safety legislation related to crew fatigue risk, where an airline can choose either to conform to the traditional flight time limitation standard or fatigue risk management system. In the United States, specifically for the purpose of data-driven rulemaking, the Airline Rulemaking Committee was formed, and operates in this capacity. Considering the advantageous results of the ARC in the US, and the D4S in Europe, this is a system that should definitely be introduced in Korea as well. A cost-benefit analysis is necessary, and can serve to strengthen the resulting legislation. In order to improve the effectiveness of data-based legislation, it is necessary to have reinforcement of experts and through them prepare a more detailed checklist of relevant variables.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.1
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• pp.3-43
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• 2018

Auf die ganze Welt macht unbemannte $Flugger{\ddot{a}}te$(sog.Drohnen) in vielen Bereichen rasch Fortschritte und Anwendungen gezeigt. Nachdem ferngesteuerte Drohnen $urspr{\ddot{u}}nglich$ $prim{\ddot{a}}r$ $f{\ddot{u}}r$ $milit{\ddot{a}}rische$ Zwecke entwickelt wurden, $erh{\ddot{o}}cht$ sich derzeit ihre zivile Nutzung sowohl im Freizeit- als auch im Dienstleistungsbereich(Paketdrohnen, Drohnen-taxi) stetig. Mit der vermehrten Drohnennutzung steigen allerdings auch die damit verbundenen Risiken und Herausforderungen. In Zusammenhang damit stellt sich dann die Frage, ob $gegenw{\ddot{a}}rtige$ Vorschriften im Bereich von Luftrecht zurecht gekommen sind. Es sieht sich gerade der zwei Schwerpunkt $gegen{\ddot{u}}ber$. Erstens kann $Passagierebef{\ddot{o}}rderung$ mit unbemanntem Luftfahrzeug(mehr als 150kg) im $gegenw{\ddot{a}}ritigen$ Luftrecht keine Anwendung finden. Denn das kor. Luftsicherheitsgesetz und sein Durchsetzungsverordnung definieren die Terminologie von unbemannten Luftfahrzeugen und unbemannten $Flugger{\ddot{a}}te$ als "wenn eine Person nicht an Bord geht und ferngesteuert wird". Also soll Drohne nach dieser gesetzlichen Definition nur "ohne Person" geflogen werden. Das besagt ohne Piloten und ohne Passagiere. Zweitens ist unbemannte $Flugger{\ddot{a}}te$(weniger als 150kg) nicht auf Handelsgesetz anzuwenden, auf das ${\ddot{u}}ber$ Anspruchsgrundlage und Zurechnungsnorm des gewerblichen Luftverkehr geregelt ist. Der unbemannte Luftfahrzeuglieferdienst bringt nicht nur die Gefahr einer $Besch{\ddot{a}}digung$ des Frachtguts mit sich, sondern auch die Gefahr von $Bodensch{\ddot{a}}den$ durch Dritte. Gemäß ${\S}$ 896 des Handelsgesetzes ist aber die Anwendung von unbemannte $Flugger{\ddot{a}}te$(weniger als 150kg) $hierf{\ddot{u}}r$ begrenzt, weil unbemannt $Flugger{\ddot{a}}te$ $einschl{\ddot{a}}gig$ in Ultralight $Flugger{\ddot{a}}t$ ist, die im Handelsgesetz ausschließlich besteht. Technische Fortschritt und die dadurch $erm{\ddot{o}}glichten$ kommerziellen Anwendungen werden die Nachfrage nach unbemannter $Flugger{\ddot{a}}te$ wecken. Die Umsetzung der $bez{\ddot{u}}glichen$ Vorschriften sollte auch diese Entwicklung aktiv begleitet und $fr{\ddot{u}}hzeitig$ kommuniziert und erarbeitet werden, damit Hersteller und Nutzer $fr{\ddot{u}}hzeitig$ Planungssicherheit haben.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.2
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• pp.129-153
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• 2017

Fair Competition policy in aviation field has been discussed since open skies policy began in 1970s. This issue has been also the main topic in the ICAO's Worldwide Air Transport Conference, the Air Transport Symposium, etc. ICAO defines competition as the existent or potential rivalry between two or more operators, carriers or groups, striving for advantages in the same market based on different prices, qualities and services. In a broader sense, the definition includes more various meanings; reasonable, fair, effective, and unrestricted competitions. Nowadays, competition laws and regulations to air transportation have been applied more frequently and the issues varies from antitrust immunity, mergers and alliances, abuse of dominant positions, capacity dumping and predatory pricing, sales and marketing, to airport charges and fees, state aid and loan guarantees. Now, the competition among the airlines or nations in aviation industry is changing to cooperation level. A lot of airlines try to survive by various cooperation methods. Therefore the policy of Korean aviation industry should be developed, taking so-called "the viewpoint of national aviation industry ecosystem" into consideration and Korean government should prepare a policy of fair competition to cope with it. First, in the process of open skies policy with neighboring countries such as China, Japan and the Middle East, it is necessary to apply the fair competition act and prepare laws and regulations to implement it. Second, the standards of effective ownership and control of air transportation business should be reviewed. Third, in preparation for aviation agreements and liberalization, the Korean aviation industry needs to study and review competition and cooperation issues through the analysis of strict aviation market structure for airlines and airport operations. Fourth, it is necessary to create a fair air transportation environment for the development of air transportation and competitiveness through preemptive policies such as the approval of mergers, acquisitions, JV and the ripple effects analysis.

• The Korean Journal of Air & Space Law and Policy
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• v.20 no.2
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• pp.9-58
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• 2005

The Warsaw Convention-officially denominated the "Convention for the Unification of Certain Rules Relating to International Transportation by Air"- is a major multilateral agreement governing the rights and responsibilities of passengers, consignor/consignee and air carriers in international transportation. Article 29(1) of the Warsaw Convention provides that the right to damages shall be extinguished if an action is not brought within 2 years, reckoned from the date of arrival at the destination, from the date on which the aircraft ought to have arrived, or from the date on which the transportation stopped. There has been disagreement as to the nature of this provision. It has been viewed on one hand as a statute of limitations, which may be tolled in appropriate circumstances. Some US Courts which have taken this approach read Article 29(2)-which states that the method of calculating the period of limitation shall be determined by the law of the court to which the case is submitted-as leaving to local law the determination of when the 2-year limitation period provided for in Article 29(1) runs. Therefore, they conclude, under Article 29(2), whenever state law would toll a state statute of limitations, the statute of limitations contained in Article 29(1) would be tolled as well. On the other hand, some other US courts have viewed the 2-year provision contained in Article 29(1) as a condition precedent to the right to bring suit, which will absolutely bar any action not brought within 2 years of the events giving rise to the action. These courts view Article 29(2) as providing only that the forum court should look to the law of the forum on the question whether the plaintiff has taken the necessary measures within the 2-year period to invoke that particular court's jurisdiction over the action. These courts have placed great weight on the "legislative" history of the Convention in reaching this position, noting in particular that the delegates to the Convention expressly considered and rejected a provision, which would have incorporated local tolling provisions.

• Electronics and Telecommunications Trends
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• v.20 no.6 s.96
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• pp.156-165
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• 2005

본 논문에서는 비신고 무선기기의 이용을 활성화하고, 전파를 효율적으로 이용하기 위하여 2005년 6, 7월에 개정된 전파법 시행령 제30조와 정보통신부 고시 제2005-29호의 개정 내용을 소개한다. 특히, 정보통신부 고시 제2005-29호는 ‘신고하지 아니하고 개설할 수 있는 무선국용 무선기기’의 무선국 분류체계 개편에 관한 것으로서, 현행 단일용도 중심의 국내 비신고 무선기기 분류를 주파수와 통신방식을 중심으로 포괄용도중심으로 재정립하여, 다양한 용도의 신규 소출력 무선기기 출현에 능동적으로 대처할수 있는 틀을 마련하였다. 또한, 본 논문에서는 포괄용도 통합에 따른 국내 소출력 무선기기의 기술기준인 ‘방송해상항공전기통신사업용외의 기타업무용 무선설비의 기술기준’의 개정방향 및 구체적인 개정안을 제시한다.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.1
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• pp.147-174
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• 2018

The air transportation industry is a field where control and interference of the state are generalized compared to other industries. However, the premise for national intervention in the air transportation industry is the determination of the nationality of the aircraft or airline company concerned. This is because it is necessary to clarify the distinction between the domestic and foreign carriers so that they can exercise airspace sovereignty. The purpose of this paper is to compare the current status and contents of Korean law and regulations on the determination of nationality with the foreign legal system. To this end, the starting point of the discussion is to look at the history of nationality restrictions on the US air transport industry and the issues that arise in the content and operation of the system today. In addition, this paper examined the provisions of the Japanese aviation law, which is very similar to that of Korea, and then compared the current legal provisions of the United States, Japan and Korea. As a conclusion, this paper sought the direction of revision of the Korean law on the basis of the foreign status of the restriction of nationality in the air transportation industry. Compared with our law, the US and Japan are generally regarded to be more concerned with the contents of their own airline companies than those of foreigners or non-citizen. In spite of the fact that there are many laws and regulations in the United States regarding the de facto dominance of domestic airline companies by foreigners, there have been a lot of controversies in this matter. By the way, Japan has been stipulating regulations on holding companies and affiliated companies. In the global era, it would be meaningful to check the status of the nationality restrictions in the aviation industry, which is based on internationality. I hope that this study will be able to build a legal institutional basis for Korea's aviation industry development from a reasonable protectionist point of view rather than a narrow nationalism in a rapidly changing era.

• 한국항공운항학회:학술대회논문집
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• 2015.11a
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• pp.13-19
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• 2015

본 연구의 목적은 자체 설계 제작한 하이브리드 발사체를 이용하여 대기 중의 미세먼지를 측정하는데 있다. 대기 중의 미세먼지를 측정하기 위한 방법으로는 중량농도법을 이용하였으며, 미세먼지 측정을 위한 포집장치를 자체 제작하였다. 엔진은 5port의 HDPE(High Density Polyethylene)를 연료 그레인으로 사용하였고 $LN_2O$(Liquefied Nitrous Oxide)를 산화제로 사용하였다. 압력, 가속도, GPS 등을 수집하며, 하이브리드 발사체의 동체는 FRP(Fiberglass Reinforced Plastics)로 제작한다. 전체 비행시간은 총 95초로 예상되며. 연소시간은 3초, 고도는 800 m 이다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.9
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• pp.649-657
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• 2019

Hydrazine, which is used as a representative monopropellant, is an extremely poisonous substance and has a disadvantage that it is harmful to the human body and is very difficult to handle. In recent years, research on the development of non-toxic and environmentally friendly propellants has attracted much attention. Ammonium dinitramide(ADN) based propellant developed by Swedish Space Corporation has superior performance to hydrazine and has been commercialized through performance verification in space environment. On the other hand, the exhaust gas from a thruster nozzle collides with a satellite while it is spreading in the vacuum space, thermal load and surface contamination may occur and may reduce the performance and lifetime of the satellite. However, a study on the effect of the exhaust gas of the green propellant thruster on the satellite has not been conducted in earnest yet. Therefore, the exhaust gas behavior in space was analyzed in this study for the ADN based green monopropellant using Navier-Stokes equations and the DSMC method. As a result, it can be expected to be used as design validation data in the development of satellite when using the ADN based green monopropellant.