• 디지털산업정보학회논문지
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• 제8권2호
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• pp.59-65
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• 2012

Emergency medical information center performs role of medical direction about disease consult and pre-hospital emergency handling scheme work to people. Emergency medical information system plays a major role to be decreased mortality and disability of emergency patient by providing information of medical institution especially when emergency patient has appeared. But, various attacks as a hacking have been happened in Emergency medical information system recently. In this paper, we proposed security structure which can protect the system securely by detecting attacks from outside effectively. Intrusion detection was performed using rule based detection technique according to protocol for every packet to detect attack and intrusion was reported to control center if intrusion was detected also. Intrusion detection was performed again using decision tree for packet which intrusion detection was not done. We experimented effectiveness using attacks as TCP-SYN, UDP flooding and ICMP flooding for proposed security structure in this paper.

• 한국철도학회논문집
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• 제5권3호
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• pp.167-173
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• 2002

The influence of thermal stress at tread breaking in Korean High Speed Train wheel was investigated using the coupled thermal-mechanical analysis technique. The mechanical load or wheel-rail contract load and braking load were considered during FEM analysis. During the stop braking, the effect of mechanical stress on the combined stress is relatively larger than that of thermal stress in the rim of wheel. However, the effect of thermal stress is relatively larger than that of mechanical stress in the plate of wheel. When 300% of the block force was applied, the maximum von Mises stress of 61.0 MPa was found at the outside plate around 400 mm far away from the wheel center.

• 대한의용생체공학회:의공학회지
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• 제17권1호
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• pp.93-98
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• 1996

The purpose of this paper is to propose a new localized imaging method of reduced imaging time luting a locally-linear gradient. Since most fast MR(Magnetic Resonance) imaging methods need the whole $\kappa$-space(Spatial frequency space) data corresponding to the whole imaging area, there are limitstions in reducing the minimum imaging time. The imaging method proposed in this paper uses a specially-made gradient coil generating a local ramp-shape field and uniform field outside of the imaging areal Conventional imaging sequences can be used without any RF/gradient pulse sequence modifiestions except the change in the number of encoding steps and the field of view.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.701-708
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• 2003

This paper presents an acoustic source localization technique on 2D cavity model in flow using a phased microphone way. Investigation was performed on cavity flows of open and closed types. The source distributions on 2D cavity flow were investigated in anechoic open-jet wind tunnel. The array of microphones was placed outside the flow to measure the far field acoustic signals. The optimum sensor placement was decided by varying the relative location of the microphones to improve the spatial resolution. Pressure transducers were flush-mounted on the cavity surface to measure the near-filed pressures. It is shown that the propagated far field acoustic pressures are closely correlated to the near-field pressures. It is also shown that their spectral contents are affected by the cavity parameter L/D.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 추계학술대회
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• pp.15-18
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• 2018

본 논문에서는 교육기관에서 이루어지는 컴퓨터 실습 등과 같이 사용자 호스트의 외부망 접속 제한이 필요한 때에, 저비용으로 간단히 접속 제어 시스템을 구축하는 기법을 제안한다. 제안된 기법은 중 간자 공격 기법(Man In The Middle, MITM) 중 하나인 ARP Spoofing을 이용하여 LAN 클라이언트에서 출발한 패킷이 게이트웨이 바깥으로 포워딩되지 않도록 하는 방식으로 클라이언트의 외부망 접속을 차단한다. 따라서 클라이언트 호스트에 별도의 방화벽이나 Agent를 설치할 필요가 없기 때문에 간편하고 경제적인 시스템 구축이 가능하다.

• 복식
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• 제53권7호
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• pp.57-68
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• 2003

The purpose of this study is to develop a creative perspective technique in fashion illustration through analyzing perspective in visual art experienced a great variety. This study was analyzed by examining the general theories based on the discovery of perspective and investigating the modern perspective in fashion illustration related to the method of spatial expression in visual art. A complex perspective of existing perspective gives the effect of reapperance of actual space and three-dimentional form in a plane. Because of being used as not only one perspective technique but also some perspectives technique, its expression can be more realistic. An amplified perspective gives the effect of visual illusion just like being suck in space inside and come out from screen outside by distorting the human body. A confused perspective of space gives the visual illusional effect of collapsing actual space and misunderstanding three-dimensional form by distorting the form of the space and changing the nature as an object of fashion. A reiterated or duplicated perspective gives effect of interpreting invisible space as imaginary space by overlapping and eliminating the object of fashion. An irrational perspective of spatial illusion gives the effect of disorganization experienced thinking by strange shapes and new recognition of irrational space by extraordinary visual connection. It has a tendency to surrealism. In conclusion, the modern perspective in fashion illustration has made the best use of not only new perspective since 1980, but general perspective before 1980. By the modern perspective expression. the viewer has made a chance to experience imaginary spaces indirectly, and the author has been able to express emotions by his or her new attempt in the screen.

• Journal of Radiation Protection and Research
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• 제47권3호
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• pp.152-157
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• 2022

Background: The hemi-body electron beam irradiation (HBIe^-) technique has been proposed for the treatment of mycosis fungoides. It spares healthy skin using an electron shield. However, shielding electrons is complicated owing to electron scattering effects. In this study, we developed a thimble-like head bolus shield that surrounds the patient's entire head to prevent irradiation of the head during HBIe^-. Materials and Methods: The feasibility of a thimble-like head bolus shield was evaluated using a simplified Geant4 Monte Carlo (MC) simulation. Subsequently, the head bolus was manufactured using a three-dimensional (3D) printed mold and Ecoflex 00-30 silicone. The fabricated head bolus was experimentally validated by measuring the dose to the Rando phantom using a metal-oxide-semiconductor field-effect transistor (MOSFET) detector with clinical configuration of HBIe^-. Results and Discussion: The thimble-like head bolus reduced the electron fluence by 2% compared with that without a shield in the MC simulations. In addition, an improvement in fluence degradation outside the head shield was observed. In the experimental validation using the inhouse-developed bolus shield, this head bolus reduced the electron dose to approximately 2.5% of the prescribed dose. Conclusion: A thimble-like head bolus shield for the HBIe^- technique was developed and validated in this study. This bolus effectively spares healthy skin without underdosage in the region of the target skin in HBIe^-.

• 인터넷정보학회논문지
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• 제20권2호
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• pp.61-68
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• 2019

대부분의 인터넷 서비스를 손쉽게 이용할 수 있다는 장점으로 인해 스마트폰 사용자가 지속적으로 증가하고 있으나, 위조앱이 급증하고 있어 스마트폰 내부에 저장된 개인정보가 외부로 유출되는 문제점이 발생하고 있다. Android 앱은 자바 언어로 개발되었기 때문에 디컴파일 과정을 수행한 후 리패키징 취약점을 역이용할 경우 손쉽게 위조앱을 만들 수 있다. 물론 이를 방지하기 위해 난독화 기술을 적용할 수 있으나 대부분의 모바일 앱에는 미적용 상태로 배포되고 있으며, 안드로이드 모바일 앱에 대한 리패키징 공격을 근본적으로 차단하는 것은 불가능하다. 또한 스마트폰 내에 앱을 설치하는 과정에서 위조 여부를 자체 검증하는 기능을 제공하지 않아 스마트폰내 저장된 개인정보가 외부로 유출되고 있다. 따라서 이를 해결하기 위해 Hyperledger Fabric 블록 체인 프레임 워크를 사용하여 정상앱 등록 과정을 구현하고 이를 기반으로 효율적으로 위조앱을 식별 및 탐지할 수 있는 메커니즘을 제시하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제30권4호
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• pp.514-519
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• 2006

SrS:Cu, Cl thin films have been grown by the hot wall technique with S furnace placed on the outside of the growth chamber in order to investigate the crystallographic and optical characteristics. The films have a good crystallinity independent of CuCl wall temperature and PL characteristics showed a peak assigned by the transition form $3d^94s^1\;(^3Eg)$ to $3d^{10}\;(^1A_{1g})$ of $Cu^+$ center. It has also been found that. from the PLE spectra, $Cu^+$ luminescent centers are doped in the host materials. The EL emission from SrS:Cu-based device showed a greenish-blue but shifted to short wavelength compared to SrS:Ce-based EL. The device was obtained the maximum luminance of $110cd/m^2$ and the maximum luminous efficiency of $0.1\;lm/W$ at $V_{40}$.

• Tribology and Lubricants
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• 제11권2호
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• pp.15-23
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• 1995

A zero-load slider is composed of two outside rails which produce a lift force pushing up the slider from the disk surface and a wide reverse step region which produces a suction force attracting the slider to the disk surface. In this paper, the flying characteristics of zero-load sliders are obtained by using an optimization technique. In the pressure calculation module, the FIFD scheme is used to solve the modified Reynolds equation. The BFGS method and a line search algorithm is employed to predict the static flying attitude. To investigate the effect of the geometric- parameters of zero-load sliders on the flying characteristics, recess depth, front step width, rail width, and taper height are varied and the corresponding flying attitudes are obtained. Simulation results demonstrate that recess depth and rail width have significant influences on the flying characteristics.