• Title/Summary/Keyword: flyer

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A Study on Shock Attenuation according to the Flyer Characteristics of a Subminiaturized EFI detonator (초소형 EFI 착화기의 비행편 특성에 따른 충격파 감쇠 연구)

  • Yu, Hyeonju;Kim, Bohoon;Jang, Seung-gyo;Kim, Kyu-Hyoung;Yoh, Jack Jaick
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.426-432
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    • 2017
  • An experimental and numerical study on shock attenuation in a solid by a subminiature flyer impact was conducted to determine the performance of a subminiature exploding foil initiator such as, flyer velocity and impulse loading. The obtained attenuation pattern shows the possibility to determine the critical flyer velocity for initiating the miniaturized pyrotechnic unit by figuring out shock intensity and duration according to flight characteristics.

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Experimental Study on the Flyer Velocity in Explosive Welding (폭발용접에서 부재의 충돌속도에 관한 실험적 연구)

  • 문정기;김청균
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.6
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    • pp.1423-1430
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    • 1993
  • One of the most important parameters for explosive welding is flyer velocity $V_p$, which principally depends on momentum caused by detonation of explosive. And close dependency with other parameters such as detonation velocity $V_D$, dynamic angle $\beta$, charge ratio R, flyer thickness $t_f$ and stand-off distance d, should be taken accounts for welding design. This paper describes, as a result of experiment, an empirical equation related to relation between $V_p$/$V_D$ and R. The flyer velocity which is estimated by $V_{p}=0.284{\times}R^{0.593}$or $V_{p}=\sqrt[0.2]{2E_G}{\times}R^{0.593}$ can be used in ordinary experiments. And the calculated values of the flyer velocity exhibit better accuracy than those of other investigators.

A Study on the Improvement of Dynamic Characteristics of the Motor Stator Coil Winding Machine (모터 고정자 코일 권선기의 동특성 개선 연구)

  • Kim, Dong-Sung;Kim, Kwang-Young;Ham, Sang-Yong;Son, Young-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.9
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    • pp.1589-1596
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    • 2003
  • In this paper, we performed the improvement study for the dynamic characteristics enhancement of the motor stator coil vertical winding machine. The dynamic characteristics improvement was done by means of the optimized design and the weight reduction of the flyer configuration, modified design of the servo control system for the flyer and the former actuation, and the development of jump timing digital circuit for the reduction of former jumping error. As the results, the maximum winding speed pattern of the developed machine was attained up to 3000rpm and also reduced the jumping error. In conclusion, domestic design technology for manufacturing the motor coil vertical winding machine was established through this study.

An Experimental Study on Performance of a Miniaturized Exploding Foil Initiator using VISAR (VISAR를 활용한 초소형 EFI 기폭 장치의 성능 특성 연구)

  • Yu, Hyeonju;Jang, Seung-gyo;Kim, Kyu-Hyoung;Yoh, Jai-ick
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.5
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    • pp.80-87
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    • 2017
  • The performance of a pyrotechnic device that consists of donor/acceptor pair separated by a bulkhead relies on shock attenuation characteristics of the gap material and shock sensitivity of the donor and acceptor explosives. In this research, a micro Kapton flyer was accelerated by an exploding foil initiator (EFI) to figure out shock sensitivity of hexanitrostilbene (HNS) to impact. The averaged shock pressure and duration imparted to the explosive by flyer impact are measured by using a velocity interferometer for any reflector (VISAR) and impedance matching technique. Consequently, this research shows the possibility to determine the critical flyer velocity for initiating the miniaturized pyrotechnic unit by determining the relations between the impact velocity, the amplitude and width of impact loading.

Design Reliability Estimation of Low Energy Exploding Foil Initiator (LEEFI형 착화장치의 설계 신뢰도 추정)

  • Lee, Minwoo;Back, Seungjun;Son, Youngkap;Jang, Seung-gyo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.5
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    • pp.40-48
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    • 2018
  • This paper presents a simulation-based design reliability estimation method of a low-energy exploding foil initiator (LEEFI) using a meta-model and describes the design reliability estimation results. The flyer velocity of the LEEFI is critical to initiate the explosive. Evaluation of the flyer velocity from mechanistic models in open literature requires a long computation time due to the multi-physical phenomena that generate the velocity. Moreover, the higher levels of confidence required for an initiator with high reliability incur higher computation costs. Thus, a meta-model of the flyer velocity over time was constructed in order to increase the computational efficiency for a reliable estimation. For different distributions and sigma levels of the design variables, the design reliability estimation results using the meta-model are provided. Additionally, the computational efficiency and accuracy of the estimation method are analyzed.

Legal approach on uniliteral changing membership in the airlines' frequent flyer program (항공사의 상용고객우대제도 변경에 관한 법적 고찰 - 미국 연방대법원의 Northwest, Inc. v. Ginsberg사례를 중심으로 -)

  • Nam, Hyun-Sook;Choi, June-Sun
    • The Korean Journal of Air & Space Law and Policy
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    • v.30 no.1
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    • pp.65-94
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    • 2015
  • Since American Airlines launched AAdvantage which was the first Frequent Flyer Program in 1981, many people has accumulated mileage credits, and now, frequent flyer program(FFP) is the universal marketing tool to the airlines. These days, airlines establish a strategic alliance with domestic and foreign companies of various fields ; other airlines, travel agencies, car hire firms, hotels, department stores, even credit card companies. However, more people want to use their mileage credits, more airlines reject to approve that or change frequent flyer program against their customers. Last year, Northwest, Inc. v. Ginsberg, the United State Supreme Court made a decision that the preemption provision of Airlines Deregulation Act(ADA) preempts state laws related to rates, routes and services for air carriers including implied covenant of good faith and fare dealing. Thus, the claim of Ginsberg was canceled, it means that Northwest Inc. could terminated one-sidedly his membership in the frequent flyer program. In the contrast, Korea does not have the statute like ADA. If customers file a claim on FFP like Ginsberg, the courts of Korea judge whether the clauses of standard form contract are unfair or not. Therefore, in this article, Ginsberg would be checked on legal issues and be compared briefly with the courts' ruling in Korea.

Analysis on Preference Values for Reward Services of FFPs by Intention of Mileage Accumulation (항공사 마일리지 적립의도에 따른 FFPs 보상서비스 선호가치 분석)

  • Park, Kwang-Sik;Yoon, Moon-Gil
    • Korean Management Science Review
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    • v.27 no.3
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    • pp.149-160
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    • 2010
  • This paper focuses on frequent flyer programs (FFPs), which have long been used by most airlines as a powerful marketing tool. Since the preference for FFPs reward services and the customer perceived values of mileage points differ among FFPs members, airlines should design a customer-oriented reward service based on customer preference to motivate the use of mileage points. The intention for using mileage points is affected by various kinds of attributes such as reword items, consuming mileage points for rewards and time of usage. In this paper, we focus on evaluating customer perceived values of attributes of FFPs reward services. A conjoint analysis model is applied to get the preference value of each attribute. Some empirical experiments are conducted in relation to Korean customers. From the empirical survey, the preference values of attributes are evaluated for different scenarios with respect to the number of mileage points. With the preference values of attributes, we can find several implications for airlines regarding the development of various FFPs strategies.

An Improvement of Lead Wire Winding Claims: A Case Study -Packing Reel and Deployment of Winding Process- (리드선 권선클레임 개선사례연구 -포장용기개량 및 권선공정전개를 중심으로-)

  • 강인선
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.25 no.1
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    • pp.49-55
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    • 2002
  • For making a lead terminal(condenser, resistor etc.), it is the matter that lead wire have to be supplied smooth without twisting and curving when it is supplied to the further processing (cutting, forming, attach process) after it being forwarded. The purpose of this study is to solve the winding claims of lead wire through the structural expansion of winding equipment to which the improvement of packing equipment to forward safely and supply the lead wire and QFD method are applied. The results of this study is available to solve the technical problem caused by the installation of the existing flyer system for the prevention of twisting and can expect the quality assurance as it prevents the claim(surface fault) caused by the bumping among lead wire which are involved in the packing equipment in its moving stage.

Design Study of Ionic Flyers (신 개념 이온 비행체의 설계 연구)

  • Lee, Ji-Hong;Joo, Sang-Hyun;Kim, Dae-Hyun
    • The Journal of Korea Robotics Society
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    • v.3 no.1
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    • pp.52-57
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    • 2008
  • A completely new flying machine is developed and the details for practical implementation is suggested. The proposed machine contains no moving parts so that it can be operated in noiseless manner. This paper presents some operational principles of the flying machine as well as the overall process of designing the basic ionic flyer model. The validation of the model is checked by experiments of test flights. Also, two conceptual design results for practical implementation are introduced with the derivation of design parameters. The application field is expected to include indoor secrete surveillance as well as ion propulsion.

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