• 제어로봇시스템학회논문지
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• 제4권3호
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• pp.301-307
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• 1998

이 논문에서는 다항식 서로소 인수로 표시되는 위너-호프 제어기의 계산상의 어려움을 극복하기 위하여 상태공간 변수 공식이 개발되었다. 위너-호프 인수 행렬을 이용하여 주어진 다항식 서로소 인수로부터 안정 유리행렬의 서로소 인수를 구하였으며 이 결과를 이용하여 위너-호프 제어기의 공식을 유리행렬의 서로소 인수로 표현한 후 이를 이용하여 상태공간 계수를 구하였다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제34권4호
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• pp.368-376
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• 2007

컴퓨터 게임에서 NPC(non-player character)가 이동하는 자연스러운 경로를 찾기 위해서는 탐색을 위한 공간을 어떻게 표현할 것인가에 대한 연구가 어떤 탐색 방법을 사용할 것인가에 대한 연구 못지 않게 중요하다고 할 수 있다. 최근까지 게염 경로 찾기의 동향을 보면 경로 계획을 위한 탐색 방법으로는 A* 알고리즘이 단연 우위를 보이지만 A* 알고리즘을 적용하기 위한 상태 공간 표현 방식으로는 게임을 위해 만들어진 여러가지 표현 방법들이 사용되고 있다. 기존의 방법들은 탐색 공간의 크기가 너무 크거나， 최적의 경로를 찾지 못하거나， 경로가 자연스럽지 못하는 등의 단점 뿐 아니라 노드와 링크의 생성이 자동적이지 못하고 레벨 디자이너에 의존하는 것도 문제점으로 지적되고 있다. 본 논문에서는 경로가 자연스럽게 보이기 위한 성질을 정의하고 이를 충족하는 경로를 생성할 수 있도록 로보틱스 분야의 가시 성그래프를 응용한 일반화 가시성그래프를 이용하여 상태공간을 표현할 것을 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권4호
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• pp.1463-1480
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• 2014

It is well known that sparse code is effective for feature extraction of face recognition, especially sparse mode can be learned in the kernel space, and obtain better performance. Some recent algorithms made use of single kernel in the sparse mode, but this didn't make full use of the kernel information. The key issue is how to select the suitable kernel weights, and combine the selected kernels. In this paper, we propose a novel multiple kernel sparse representation based classification for face recognition (MKSRC), which performs sparse code and dictionary learning in the multiple kernel space. Initially, several possible kernels are combined and the sparse coefficient is computed, then the kernel weights can be obtained by the sparse coefficient. Finally convergence makes the kernel weights optimal. The experiments results show that our algorithm outperforms other state-of-the-art algorithms and demonstrate the promising performance of the proposed algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권6호
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• pp.2709-2729
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• 2016

Representation based classification, kernel method and sparse representation have received much attention in the field of face recognition. In this paper, we proposed an improved kernel principal component analysis method based on sparse representation to improve the accuracy and robustness for face recognition. First, the distances between the test sample and all training samples in kernel space are estimated based on collaborative representation. Second, S training samples with the smallest distances are selected, and Kernel Principal Component Analysis (KPCA) is used to extract the features that are exploited for classification. The proposed method implements the sparse representation under ℓ₂ regularization and performs feature extraction twice to improve the robustness. Also, we investigate the relationship between the accuracy and the sparseness coefficient, the relationship between the accuracy and the dimensionality respectively. The comparative experiments are conducted on the ORL, the GT and the UMIST face database. The experimental results show that the proposed method is more effective and robust than several state-of-the-art methods including Sparse Representation based Classification (SRC), Collaborative Representation based Classification (CRC), KCRC and Two Phase Test samples Sparse Representation (TPTSR).

• 한국컴퓨터정보학회논문지
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• 제24권2호
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• pp.1-7
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• 2019

This paper presents CTP (Compact Translation Page), a compact representation of translation pages, for page mapping-based flash translation layers to improve RAM utilization and reduce the response time of solid state drives. CTP can store translation information twice in a translation page and the total number of translation pages stored in flash is reduced to half. Therefore, CTP halves the RAM size of the directory of translation pages and uses the saved RAM space for translation cache. CTP shows the best response time when compared to existing page mapping-based flash translation layers.

• 한국항공운항학회지
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• 제17권1호
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• pp.9-16
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• 2009

The analysis of an aircraft flight dynamics is recently very convenient because of the introduction of state-space method and a well-developed package software. The representation of a dynamic system is described as a simple form of matrix calculation and the unique form of model is available for the linear or nonlinear, time variant or time invariant, mono variable or multi variable system with state-space method. And this analysis can be simplified with the specific functions of a package software and it is very simplified to execute the simulation of the dynamic characteristics for an aircraft model with an interactive graphical treatment. The purpose of this study is to develope an educational flight simulator for the students who need to analyze the dynamic characteristics of an aircraft that is primarily to execute the simulation for the analysis of the transient response and frequency response of an aircraft stability. Furthermore the dynamic characteristics of an aircraft motion is set up as dynamical animation tool for the control response on 3-axis motions of an aircraft.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권3호
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• pp.813-829
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• 2022

In multi-view subspace clustering, how to integrate the complementary information between perspectives to construct a unified representation is a critical problem. In the existing works, the unified representation is usually constructed in the original data space. However, when the data representation in each view is very diverse, the unified representation derived directly in the original data domain may lead to a huge information loss. To address this issue, different to the existing works, inspired by the latest revelation that the data across all perspectives have a very similar or close spectral block structure, we try to construct the unified representation in the spectral embedding domain. In this way, the complementary information across all perspectives can be fused into a unified representation with little information loss, since the spectral block structure from all views shares high consistency. In addition, to capture the global structure of data on each view with high accuracy and robustness both, we propose a novel low-rank approximation via the tight lower bound on the rank function. Finally, experimental results prove that, the proposed method has the effectiveness and robustness at the same time, compared with the state-of-art approaches.

• Journal of Positioning, Navigation, and Timing
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• 제11권4호
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• pp.263-268
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• 2022

Precise Point Positioning-Real Time Kinematic (PPP-RTK) is a high accuracy positioning method that combines RTK and PPP to overcome the limitations on service coverage of RTK and convergence time of PPP. PPP-RTK provides correction data in the form of State Space Representation (SSR), unlike RTK, which provides measurement-based Observation Space Representation (OSR). Due to this, PPP-RTK has an advantage that it can transmit less data than RTK. So, recently, several techniques for PPP-RTK have been proposed. However, in order to utilize PPP-RTK techniques, performance analysis of these in a real environment is essential. In this paper, we implement the local network PPP-RTK and analyze the positioning performance according to the distance within 100 km from the reference station in Korea. As results of experiment, the horizontal and vertical 95% errors of local network PPP-RTK were 6.25 cm and 5.86 cm or less, respectively.

• 전기의세계
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• 제21권6호
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• pp.9-16
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• 1972

This work intends to study the machine dynamics in the state-space approah and to formulate the operating characteristics of a namplidyne generator, with balanced control field winding and an auxiliary feedback winding for compensating purpose. In the derivation of the dynamic equation, investigations on the demagnetization effects are accentuated, based on the magnetic interlinks between windings of the machine. From the machine dynamic relation obtained, a state-variable representation of the machine dynamics is approached in the first part of this work.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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• pp.255-259
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• 1996

This paper presents active vibration control of a rotating cantilevered beam using piezoceramic actuators. A governing equation of motion is obtained by the Hamilton's principle and expressed in the state space representation. Subsequently, an H$_{\infty}$ control which is robust to system uncertainties is synthesized through the loop shaping design procedure. Computer simulations for the steady-state vibration control are undertaken in order to demonstrate the effectiveness and robustness of the proposed control methodology..y.