• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2006년도 춘계학술대회논문집
• /
• pp.660-665
• /
• 2006

This paper presents a finite element method to analyze the free and forced vibration of a hard disk drive (HDD) considering the flexibility of a spinning disk-spindle with fluid dynamic bearings (FDBs), an actuator with pivot bearings, an air bearing between head-disk interface and the base with complicated geometry. Finite element equation of each component is consistently derived with the satisfaction of the geometric compatibility of the internal boundary between each component. The spinning disk, hub and FDBs are modeled by annular sector elements, beam elements and stiffness and damping elements, respectively. The actuator am, E-block, suspension and base plate are modeled by tetrahedral elements. The pivot bearing in the actuator and the air bearing between head-disk interfaces are modeled by the stiffness element with five degrees of freedom and the axial stiffness, respectively. A global matrix equation obtained by assembling the finite element equations of each substructure is transformed to a state-space matrix-vector equation, and both damped natural frequencies and modal damping ratios are calculated by solving the associated eigenvalue problem with the restarted Arnoldi iteration method. Modal and shock testing are performed to show that the proposed method well predicts the vibration characteristics of a HDD.

• 산업경영시스템학회지
• /
• 제38권4호
• /
• pp.212-225
• /
• 2015

UAV (Unmanned Aerial Vehicle), the pilotless plane or drone, draws researchers' attention at these days for its extended use to various area. The research was initiated for military use of the UAV, but the area of applicable field is extended to surveillance, communication, and even delivery for commercial use. As increasing the interest in UAV, the needs of research for operating the flying object which is not directly visible when it conducts a certain mission to remote place is obviously grown as much as developing high performance pilotless plane is required. One of the project supported by government is related to the use of UAV for logistics fields and controlling UAV to deliver the certain items to isolated or not-easy-to-access place is one of the important issues. At the initial stage of the project, the previous researches for controlling UAV need to be organized to understand current state of art in local researches. Thus, this study is one of the steps to develop the unmanned system for using in military or commercial. Specifically, we focused on reviewing the approaches of controlling UAV from origination to destination in previous in-country researches because the delivery involves the routing planning and the efficient and effective routing plan is critical to success to delivery mission using UAV. This routing plan includes the method to avoid the obstacles and reach the final destination without a crash. This research also present the classification and categorization of the papers and it could guide the researchers, who conduct researches and explore in comparable fields, to catch the current address of the research.

• 항공우주정책ㆍ법학회지
• /
• 제30권2호
• /
• pp.279-310
• /
• 2015

몬트리올협약은 국제항공운송에서 발생한 사고에 따른 여객의 사망이나 상해에 관하여 항공운송인의 책임을 배타적으로 규율하고 있다. 국제항공산업의 재정적인 안정과 항공사를 파산으로 이끌 수도 있는 과도한 배상책임으로부터 항공산업을 보호할 목적으로 몬트리올협약은 금전배상에 있어서 책임제한제도를 운영하고 있다. 하지만 여객의 사망이나 상해가 항공사 혹은 그 대리인의 직접적인 과실이나 불법적인 작위 혹은 부작위의 결과라는 점이 인정될 경우에 그러한 책임제한원칙은 유지될 수 없고, 손해배상을 청구하는 자는 협약이 정하는 제한책임액 이상의 배상을 받을 수도 있다. 한편, 몬트리올협약은 손해배상을 청구하는 원고가 소송을 제기할 수 있는 법정지에 관해서도 관할권 관련 조항에서 일정한 제한을 두고 있다. 이러한 관할권은 특히 피고 항공운송인의 영업소나 원고의 주소지가 주요 결정요인이 된다. 지난 2015년 3월, Germanwings 항공사 9525편에 발생한 사고는 당시 심한 우울증을 앓고 있었던 부기장의 의도적인 행동이 원인이었고, 해당 항공기가 프랑스령 알프스산맥에 추락하면서 대부분의 탑승 여객과 승무원의 사망이라는 결과로 이어졌다. 보도 자료에 따르면 사고 직후, 항공사는 사망승객의 국적에 따라 금액의 차이는 있지만 미화 8,300불에서 4백5십만불에 이르는 손해배상액을 합의금으로 제시하였다고 한다. 이러한 합의제안에 대해 몇몇 유가족들은 보다 많은 배상액을 얻기 위하여 미국과 같이 피해자에게 관대한 법정지에서 소송제기를 계획하고 있다고 한다. 본 논문은 위 사고와 관련하여 두 가지 쟁점에 관하여 기술하고 있다. 첫째, 본 논문은 몬트리올협약상 관할권 조항과 관련하여 미국 시민이 아닌 피해자가 미국 법정지에서 소송을 제기할 가능성에 대해 살펴보았다. 둘째, 본 사고의 직접적인 원인이 부기장의 의도된 사고유발 행동이었던 점에서 사안의 항공사는 몬트리올협약이 규정하고 있는 책임제한원칙이 부정될 가능성이 있다. 이에 관하여 본 논문은 해당 항공사가 그럼에도 불구하고 협약상 책임제한규정을 원용할 수 있는 가능성이 있는지 여부를 중점적으로 살펴보았다.

• 한국기계가공학회지
• /
• 제14권1호
• /
• pp.63-69
• /
• 2015

Recently, research and interests in pilotless and radio-controlled quadcopters have increased due to military, hobby, and air-photo applications. However, quadcopters are fragile and can very easily to break when they crash. Therefore, it is necessary to create a protective device such that these devices can protect the main board, motor, and propellers from outside impacts. In this paper, a protective device for a quadcopter is designed in the form of a circle to disperse shock. Also, a dropping and impact simulation was performed to verify that the quadcopter can be efficiently protected when using the proposed device, created with the commercial finite element software Solidworks.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
• /
• pp.562-564
• /
• 2001

Transformation of molecular film occurs only usually in air-water interface, 2 dimensions domain's growth and crash are achieved. Organic matter thin film that accumulate molecular film in archaism board only that consist of growth of domain can understand correct special quality of accumulation film supplying information about fine structure and properties of matter of device observing information and so on that is surface forward player and optic enemy using AFM one of SPM application by nano electronics. The stable images are probably due to a strong interaction between the monolayer film and glass substrate. We are unable to obtain molecule resolution in images of the films but did see a marked contrast between images of the bare substrate and those with the network structure film deposited onto it. Formation that prevent when gas phase state and liquid phase state measure but Could know organic matter that molecules form equal and stable film when molecules were not distributed evenly. and accumulated in solid state only.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 C
• /
• pp.1618-1620
• /
• 2002

Transformation of molecular film occurs only usually in air-water interface, 2 dimensions domain's growth and crash are achieved. Organic matter thin film that accumulate molecular film in archaism board only that consist of growth of domain can understand correct special quality of accumulation film supplying information about fine structure and properties of matter of device observing information and so on that is surface forward player and optic enemy using AFM one of SPM application by nano electronics. The stable images are probably due to a strong interaction between the monolayer film and glass substrate. We are unable to obtain molecule resolution in images of the films but did see a marked contrast between images of the bare substrate and those with the network structure film deposited onto it. Formation that prevent when gas phase state and liquid phase state measure but Could know organic matter that molecules form equal and stable film when molecules were not distributed evenly, and accumulated in solid state only.

• Applied Science and Convergence Technology
• /
• 제24권2호
• /
• pp.27-32
• /
• 2015

We analyzed the destruction patterns of a turbo-molecular pump (TMP) resulting from its sudden exposure of a foreline to the atmospheric pressure due to a destruction of the foreline connecting clamp of an ICP dry etcher for 300 mm wafers during high-vacuum operation ($5{\times}10^{-6}$ Torr). Unlike in the case of view port's breakage, the TMP's rotor module was crashed inside the chamber. The primary damage resulted from the collision of the blades and stators, and the secondary damage resulted from the breaking of the rotor - driving shaft assembly. The fixing screws of the rotor and axial shaft were bent and broken when the TMP controller output the maximum current even after the crash event. Electrical power consumption analysis of the TMP power controller confirmed it. The stress distributions were analyzed by a finite element method using CFD-ACE+ multi physics software. Rotating inertia of each parts and kinetic energies were calculated as well. 68% of the rotational kinetic energy is deposited by the rotor - shaft module.

• 한국항공운항학회지
• /
• 제23권4호
• /
• pp.125-132
• /
• 2015

항공기 추락 시 충돌충격단계에서 사상자가 가장 많이 발생하는 것으로 나타나고 있다. 대부분의 경우, 승객들은 두부손상으로 의식을 잃게 되어 비상탈출에 실패하여 사망에 이르게 된다. 이에 대한 대응책으로 항공기 제작사들은 내구성이 강화된 항공기 좌석을 설계 및 제작하여 설치하고 있다. 객실에서는 승객들이 충격방지자세를 취함으로써 부상을 최소화할 수 있다. 승객들에 대한 충격방지자세 안내는 모든 항공사가 시간적 여유가 있는 비상상황에서만 객실승무원이 안내방송과 함께 시범을 보이도록 절차가 수립되어 있다. 그러나 갑작스런 사고의 경우 승객들은 충격방지자세에 대한 정보를 전달받지 못한 상태에서 사상의 위험에 직면하게 된다. 본 논문은 SHEL 모델을 적용하여 승객과 사상자발생 환경, 승객과 충격방지를 위한 안전절차, 승객과 승객안전정보 전달매체, 승객과 객실승무원등의 상호작용에 내재된 위해요소를 체계적으로 규명하고 객실안전에 대한 법규 및 절차 등의 개정을 제시함으써, 항공기사고로 인한 사상자 발생에 대한 근본적인 대안을 제시하여 항공안전 증진에 기여하고자 한다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집
• /
• pp.562-564
• /
• 2001

Transformation of molecular film occurs only usually in air-water interface, 2 dimensions domain's growth and crash are achieved. Organic matter thin film that accumulate molecular film in archaism board only that consist of growth of domain can understand correct special quality of accumulation film supplying information about fine structure and properties of matter of device observing information and so on that is surface forward player and optic enemy using AFM one of SPM application by nano electronics. The stable images are probably due to a strong interaction between the monolayer film and glass substrate. We are unable to obtain molecule resolution in images of the films but did see a marked contrast between images of the bare substrate and those with the network structure film deposited onto it. Formation that prevent when gas phase state and liquid phase state measure but Could know organic matter that molecules form equal and stable film when molecules were not distributed evenly, and accumulated in solid state only.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 C
• /
• pp.1580-1582
• /
• 2003

Transformation of molecular film occurs only usually in air-water interface, 2 dimensions domain's growth and crash are achieved. Organic thin film that consist of growth of domain can understand correct special quality of accumulation film supplying information about fine structure and properties of matter of device observing information and so on that is surface forward player and optic enemy using AFM one of SPM application by nano electronics. In this paper Langmuir (L) that is one of basis technology to manufacture of organic matter device using Biology material PBDG that is kind of polypeptide that have Biology adaptedness. Detected of accumulation condition in observing Surface Pressure change by stimulus reaction of Langmuir (L) and Spin-Coating film. Therefore AFM by this confirm and compared.