• 한국정보처리학회논문지
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• 제6권11S호
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• pp.3320-3331
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• 1999

In this paper, we explore two ways to improve the bandwidth assurance performance of Assured Service(AS). It is well known that AS fails to meet the bandwidth assurance target for large-profile TCP flows competing with many small-profile flows. This flows after the back-offs induced by packet drops. Thus currently proposed solution to this problem naturally focus on modifying TCP's behavior to counter the unfairness in the TCP dynamics. Unfortunately, these proposals lack practicability in terms of the required changes in the incumbent Internet infrastructure. Admitting this difficulty, we instead look to not yet deployed Diff-Serv mechanisms for practical solutions. In particular, we investigate the role of RIO, RED with IN(in-profile) and OUT(out-profile), queue management scheme in the assurance failure for As. Specifically, we identify the inadequacy of RIO that aggravates the bandwidth assurance failure. Then we alleviates the bandwidth assurance failure problem by separately controlling the out-of-profile packet queue length. Through extensive simulations we demonstrate that RI+O extends the regime where AS consistently provides the bandwidth assurance.

• 한국전자파학회논문지
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• 제24권3호
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• pp.292-298
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• 2013

본 논문에서는 미사일의 길이를 추정하는 신호 처리 기법의 개발에 관하여 소개한다. 표적의 길이를 추정하기 위해서는 미사일의 위치 및 표적과 레이더와의 각도 정보가 필요하다. 미사일의 위치 및 각도를 알아내기 위해서 chirp 파형을 사용했고, 레이더 영상 신호인 HRRP(High Resolution Range Profile)를 발생시키기 위해 stretch processing을 이용하였다. HRRP로부터 표적의 산란점(scattering center)을 찾기 위해 스펙트럼 추정 방법(spectral estimation technique)인 Relaxation(RELAX) 알고리즘을 이용하였다. 이 알고리즘으로부터 얻은 1차원 산란점의 정보를 이용하여 미사일의 길이를 추정하였다.

• Wind and Structures
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• 제5권2_3_4호
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• pp.291-300
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• 2002

An efficient large eddy simulation algorithm is used to compute surface pressure distributions on an eleven story (target) building on the NIST campus. Local meteorology, neighboring buildings, topography and large vegetation (trees) all play an important part in determining the flows and therefore the pressures experienced by the target. The wind profile imposed at the upstream surface of the computational domain follows a power law with an exponent representing a suburban terrain. This profile accounts for the flow retardation due to friction from the surface of the earth, but does not include fluctuations that would naturally occur in this flow. The effect of neighboring buildings on the time dependent surface pressures experienced by the target is examined. Comparison of the pressure fluctuations on the single target building alone with those on the target building in situ show that, owing to vortices shed by the upstream buildings, fluctuations are larger when such buildings are present. Even when buildings are lateral to or behind the target, the pressure disturbances generate significantly different flows around this building. A simple grid-free mathematical model of a tree is presented in which the trunk and the branches are each represented by a collection of spherical particles strung together like beads on a string. The drag from the tree, determined as the sum of the drags of the component particles, produces an oscillatory, spreading wake of slower fluid, suggesting that the behavior of trees as wind breakers can be modeled usefully.

• 한국산업융합학회 논문집
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• 제26권5호
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• pp.885-894
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• 2023

Setting RAM target value for a defense system plays a crucial role in the development and design phases and the production phase as well. It is apparent that the achieved RAM target value can help maximizing the combat capability of a defense system and improving its performance throughout the system's life cycle from acquisition phase to disposal. Usually a defense system operates according to its OMS/MP (Operational Mode Summary / Mission Profile) and it consists of several subsystems which are supposed to be operated at each utilization rate under its operating conditions and the mission profiles assigned. In this study, a method of setting RAM target value is proposed for a defense system that are composed of several independent subsystems considering their utilization rates and the mission profiles assigned. And the case study of applying the proposed method of setting RAM target value to system A is dealt with.

• Journal of Korean Vacuum Science & Technology
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• 제3권2호
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• pp.101-106
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• 1999

The main consideration factor to design a magnetron of the sputtering system for TFT-LCD metallization is high sheet resistance (Rs) uniformity which is provided by the high target erosion and high current efficiency. The present study has developed a rectangular magnetron for TFT-LCD to bve considered full target erosion and high film uniformity. After an aluminum-2 at.% and alloy target was installed in a magnetron source and the film was deposited on the glass of 600${\times}$720 mm, the Rs uniformity of the deposited film was measured as functions of the magnet tilt and magnet scanning configuration. And the target erosion profile was observed with the target voltage. When sputtered at 4mtorr and 10kW, the magnet tilt for the high Rs uniformity of 8.38% was 7mm. The plasma voltage at the dwell home and end for full-face target erosion, when scanned the magnetron was 120% compared to the mean voltage of the other area.

• 한국군사과학기술학회지
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• 제22권2호
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• pp.207-214
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• 2019

This paper proposes a new feature extraction method for automatically estimating the number of target and detecting the chaff using high range resolution profile(HRRP). Feature of one-dimensional range profile is expected to be limited or missing due to lack of information according to the time. The proposed method considers the dynamic movements of targets depending on the radial velocity. The observed HRRP sequence is used to construct a time-range distribution matrix, then assuming diverse radial velocities reflect the number of target and seduction chaff launch, the proposed method utilizes the characteristic of the gradient distribution on the time-range distribution matrix image, which is validated by electromagnetic computation data and dynamic simulation.

• 한국기계가공학회지
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• 제20권1호
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• pp.34-41
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• 2021

Interventional radiology and minimally invasive surgery both require a precisely shaped microcatheter. Microcatheters are manufactured using polymer extrusion processes with a die and puller. The manufacturing parameters and die geometry greatly influence the profile of the extrudate and designing dies using a trial-and-error process is expensive and requires a lot of time. Therefore, predicting the profile of the extrudate is important for manufacturing microcatheters. This study investigates the effects of die design and geometry on the profile of the extrudate. The profiles of the extrudate are predicted using ANSYS Polyflow with respect to the different die geometries. The outer and inner diameters and wall thickness of the predicted extrudate are compared to those of a target extrudate. The die swell of melt polymer and the effect of the pulling are both examined. Optimized die designs are suggested for manufacturing the target extrudate.

• 소프트웨어공학소사이어티 논문지
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• 제13권3호
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• pp.92-97
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• 2000

양질의 소프트웨어제품과 서비스를 생산하는 방법은 우수한 선례를 답습하거나, 성공한 선례를 해당 응용업무에 맞도록 발전시키는 것이다. 즉 프로세스들의 모임인 소프트웨어 프로세스를 각각의 소프트웨어 서비스와 시스템의 개발목적에 부합하도록 정의하는 것이다. 프로세스 모임은 정보화사업의 포괄적 관리가 가능하게하며, 사업제기부서가 소프트웨어 시스템에 대한 전반적인 의무와 책임을 갖게 하며, 정보화사업 감리에 있어서 감리 목표 정립과 감리의 시행을 명확하게 한다. 소프트웨어 서비스 및 시스템 개발에 있어서 적합한 프로세스의 모임을 목표프로세스 프로파일(Target Process Profile) 이라고 명명하였다. TPP을 정의함에 있어서는 정의할 대상시스템의 성능과 시스템의 효과성이 어느 정도 가시화되는 여건에서, 소프트웨어 서비스 및 시스템의 수명주기 목표, 수명주기 아키텍쳐 및 수명주기 계획을 도출한다. 즉 아키텍쳐 접근방법, 소프트웨어프로세스의 정착, 및 국제표준의 프로세스에서의 프로세스 모임규칙을 근간으로 하여 TPP의 프레임워크(Framework)을 시안을 작성하였다. 소프트웨어공학의 발전과정에서 프로세스 능력의 성숙도 기준으로 프로세스 모임을 이룬것에 추가하여, 논자는 ISO/IEC 15504 TR 프로세스간의 전후관계에서 TPP을 위한 작업산출물 도출방법을 정의하였다. TPP에 의한 정보화추진은 정보화시대에서 소프트웨어 품질 및 가격에서 경쟁력을 가져오는 요인이 될 것이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2747-2749
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• 2003

Security is concerned with the protection of assets from threats, where threats are categorised as the potential for abuse of protected assets. All categories of threats should be considered, but in the domain of security greater attention is given to those threats that are related to malicious or other human activities ISO/IEC 15408 requires the TOE(Target of Evaluation) Security Environment section of a Protection Profile(PP) or Security Target(ST) to contain a list of threats about the TOE security environment or the intended usage of the TOE. This paper presents a specific physical threats should be considered in the smart card PP which developers of smart card PP must consider.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2650-2659
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• 2022

The dense granular flow spallation target is a new target concept proposed for an Accelerator-Driven Sub-critical (ADS) system. In this paper, the beam-target configurations of a tungsten granular flow target for the ADS with a thermal power of 1 GW is explored. The beam profile options using different scanning methods are discussed. The critical geometry parameters are adjusted to investigate the performance of the granular target from the aspects of neutron efficiency, stability and temperature distribution in target medium. To figure out how the target under accident conditions would behave, different clogging conditions are induced in the simulation. The dynamic processes are analyzed and some important parameters such as abnormal temperature rise and beam cutoff time window are obtained. The response of the sub-critical reactor to a clogging accident is also investigated. It is indicated that the monitoring of the granular flow by the neutron detectors in the sub-critical core will be effective.