• International Journal of Aeronautical and Space Sciences
• /
• 제6권2호
• /
• pp.33-45
• /
• 2005

The 1/9-scale model of a fighter-type configuration was tested in the Micro-Craft 8ft ${\times}$ 12ft wind tunnel facility. An abrupt lift dump was found at a certain range of angle of attack under the pre-scheduled approach configuration. To avoid a probable unsatisfactory flight behavior due to the lift dump, various aerodynamic devices were suggested. Extensive tests applying the cutoff leading edge flaps, boundary layer fences, saw tooth and vortex generators were performed with flow visualization as well as force and moment measurements. Test results showed that the origin of the lift dump was caused by the secondary boundary layer flow separation generated from the strong interaction between wing and flap. Various solutions for avoiding the unfavorable feature were suggested with the merits and demerits.

• 한국시뮬레이션학회논문지
• /
• 제13권4호
• /
• pp.55-69
• /
• 2004

In MANET(Mobile Ad-hoc Network), unlike in wired networks, a path configuration should be in advance of data transmission along a routing path. Frequent movement of mobile nodes, however, makes it difficult to maintain the configured path and requires re-configuration of the path very often. It may also leads to serious problems such as deterioration of QoS in mobile ad-hoc networks. In this paper, we proposed a Reactive Routing Keyword (RRK) routing procedure to solve those problems. Firstly, we noticed it is possible in RRK routing to assign multiple routing paths to the destination node. We applied this feature into active networks and SNMP information based routing by storing unique keywords in cache of mobile nodes corresponding to present and candidate routings in a path configuration procedure. It was shown that the deterioration of QoS which may observed in Dynamic Source Routing(DSR) protocol was greatly mitigated by using the proposed routing technique.

• 융합보안논문지
• /
• 제17권3호
• /
• pp.51-57
• /
• 2017

VOD 서비스는 일반 유료방송가입자들 사이의 보편적인 인기뿐만 아니라 가입자 기반 수신료, 광고료와 같은 기존 방송사의 수익 외의 추가 수익을 제공하고 있다. 이와 같은 이유로 각 방송사들은 자신의 VOD 서비스를 개발하고 매출을 높이기 위해 잦은 개선 작업을 수행하기 때문에 개발업체는 이런 개발 요구들에 효과적으로 대응할 방법이 필요한 실정이다. 이 에 본 연구는 사례연구들을 통해 그 효율성이 입증된 대표적 피처지향 분석모델인 FODA (Feature-Oriented Domain Analysis)를 VOD 서비스 개발에 적용하였다. FODA는 카네기멜론대학 SEI에서 개발한 피처지향 분석모델로서 특정 도메인에 해당하는 소프트웨어의 피처모델을 개발하고 이를 기반으로 고객이 원하는 소프트웨어 형상을 결정하는 도구를 제공한다. 본 연구는 개발업체와 함께 VOD 서비스 도메인의 피처모델을 개발하고 VOD 서비스 개발 프로세스 향상을 위한 피처모델 기반의 VOD 서비스 기능과 테스트케이스들을 개발하였다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
• /
• pp.216-216
• /
• 2012

The interaction of hydrogen with ZnO single crystal surfaces, ZnO (0001), ZnO (000-1), and ZnO (10-10) has been investigated using temperature programmed desorption (TPD) and X-ray photoelectron Spectroscopy (XPS) techniques. When the ZnO single crystal surfaces are exposed to atomic hydrogen at 200 K, all three surfaces show hydrogen desorption at 450 K. ZnO (0001) surface shows hydrogen desorption feature at ~260 K as the hydrogen exposure is increased. The ZnO (10-10) surface shows low-temperature desorption feature first and the high-temperature desorption feature appears as the hydrogen exposure increases. The ZnO (000-1) surface does not show any lower temperature hydrogen desorption. We will report the adsorption configuration of hydrogen atoms on ZnO single crystal surfaces with different surfaces structures.

• International Journal of CAD/CAM
• /
• 제5권1호
• /
• pp.69-81
• /
• 2005

As collaborative design and configuration design gain increasing importance in product development, it becomes essential to exchange parametric CAD models among participants. Parametric CAD models can be represented and exchanged in the form of a macro file or a part file that contains the modeling history of a product. The modeling history of a parametric CAD model contains feature specifications and each feature has selection information that records the name of the referenced topological entities. Translating this selection information requires solving the problems of how to identify the referenced topological entities of a feature (persistent naming problem) and how to convert the selection information into the format of the receiving CAD system (naming mapping problem). The present paper introduces the problem of exchanging parametric CAD models and proposes a solution to naming mapping.

• Journal of Electrical Engineering and Technology
• /
• 제10권4호
• /
• pp.1851-1863
• /
• 2015

– In the paper, to handle the problem of traditional bag-of-features model ignoring the spatial relationship of local features in human action recognition, we proposed a Multiscale Spatial Position Coding under Locality Constraint method. Specifically, to describe this spatial relationship, we proposed a mixed feature combining motion feature and multi-spatial-scale configuration. To utilize temporal information between features, sub spatial-temporal-volumes are built. Next, the pooled features of sub-STVs are obtained via max-pooling method. In classification stage, the Locality-Constrained Group Sparse Representation is adopted to utilize the intrinsic group information of the sub-STV features. The experimental results on the KTH, Weizmann, and UCF sports datasets show that our action recognition system outperforms the classical local ST feature-based recognition systems published recently.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2008년도 한국컴퓨터종합학술대회논문집 Vol.35 No.1 (B)
• /
• pp.38-43
• /
• 2008

특성 모델(Feature Model)은 소프트웨어 제품 라인 개발 시 도메인 공학 단계에서 제품들 사이의 공통점과 차이점을 모델링하는데 널리 사용된다. 특성 구성(Feature Configuration)은 특성 모델로부터 특정 제품에 포함될 특성들을 선택한 결과이다. 특성 구성은, 특성 모델에 표현되어 있는 여러 가지 제한 조건을 만족해야 한다. 본 논문에서는 특성 모델 작성 기능과 특성 구성 정의 기능을 지원하고 특성 구성의 검증 기능을 지식 기반 시스템인 JESS를 활용하여 구현한 특성 모델링 도구를 제안한다. 본 도구는 자바 언어와의 결합성이 좋은 JESS 시스템을 이용하여 확장성이 좋으며 특성 구성에서의 오류 원인을 명확히 알려주는 장점을 가진다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권9호
• /
• pp.3721-3737
• /
• 2015

3D reconstruction based on binocular data is significant to machine vision. In our method, we propose a new and high efficiency 3D reconstruction approach by using a consumer camera aiming to: 1) address the configuration problem of dual camera in the binocular reconstruction system; 2) address stereo matching can hardly be done well problem in both time computing and precision. The kernel feature is firstly proposed in calibration stage to rectify the epipolar. Then, we segment the objects in the camera into background and foreground, for which system obtains the disparity by different method: local window matching and kernel feature-based matching. Extensive experiments demonstrate our proposed algorithm represents accurate 3D model.

• Journal of Electrical Engineering and Technology
• /
• 제8권2호
• /
• pp.385-392
• /
• 2013

An uncalibrated visual servo control method for tracking a target is presented. We define the robot-positioning problem as an unconstrained optimization problem to minimize the image error between the target feature and the robot end-effector feature. We propose a method to find the residual term for more precise modeling using the secant approximation method. The composite image Jacobian is estimated by the proper method for eye-to-hand configuration without knowledge of the kinematic structure, imaging geometry and intrinsic parameter of camera. This method is independent of the motion of a target feature. The algorithm for regulation of the joint velocity for safety and stability is presented using the cost function. Adaptive regulation for visibility constraints is proposed using the adaptive parameter.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 하계학술대회 논문집 G
• /
• pp.2312-2314
• /
• 1998

To improve the visual servoing performance, several strategies were proposed in the past such as redundant feature points, using a point with different height and weighted selection of image features. The performance of these visual servoing methods depends on the configuration between the camera and object. And redundant feature points require much computation efforts. This paper proposes the visual servoing m based on the disturbance observer, which compe the upper off-diagonal component of image fe Jacobian to be null. The performance indices su sensitivity for a measure of richness, sensitiv the control to noise, and controllability are sho improved when the image feature Jacobian is giv a block diagonal matrix. Computer simulation carried out for a PUMA560 robot and show results to verify the effectiveness of the pro method.