Stabilization of a Memristor-based Chaotic System by Intermittent Control and Fuzzy Processing

Junjian Huang,Chuandong Li,Xing He 제어·로봇·시스템학회 2013 International Journal of Control, Automation, and Vol.11 No.3

This paper further investigates the problem of intermittent control of a memristor-based Chua’s oscillator and presents the oscillator as the T-S fuzzy model system. Based on Lyapunov stability theory, we design an intermittent controller to guarantee the stability of the chaotic system. Simulation results are presented to verify the effectiveness of the method.

Event-triggered Bipartite Consensus for Multi-agent Systems with Antagonistic Interactions

Junjian Li,Xia Chen,Fei Hao,Jing Xie 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.8

This paper investigates event-triggered control for first-order multi-agent systems with structurally balanced signed graphs. A distributed continuous event-triggered consensus mechanism is firstly proposed for each agent, including the control law based on local sampled states, and the triggering condition constructed with its own state, the sampled states of itself and its neighbours, and an extra signal. No knowledge of the global network is needed. By applying Lyapunov stability theory and the algebraic graph theory, we prove that all agents can reach agreement with identical magnitude but opposite sign while Zeno behaviour is excluded. Moreover, the periodic implementation of the event triggered consensus algorithm is proposed. The criteria of co-designing the triggering condition parameter and the verification period is established to guarantee the bipartite consensus of the systems. Finally, simulations, including a numerical example and a group of multiple mobile robots, are shown to illustrate the efficiency of the proposed theoretical results.

Screening of the Antigen Epitopes of Basic Fibroblast Growth Factor by Phage Display

Xiang, Junjian,Zhong, Zhenyu,Deng, Ning,Zhong, Zhendong,Yang, Hongyu Korean Society for Biochemistry and Molecular Biol 2005 Journal of biochemistry and molecular biology Vol.38 No.3

In order to investigate the epitope of basic fibroblast growth factor (bFGF) and its immunogenicity, the epitopes of bFGF were screened from the phage display library with monoclonal antibody GF22, which can neutralize the bio-activity of bFGF. By three rounds of screening, the positive phage clones with bFGF epitopes were selected, which can effectively block the bFGF to bind with GF22. Sequence analysis showed that the epitopes shared a highly conservative sequence (Leu-Pro-Pro/Leu-Gly-His-Phe/Ile-Lys). The sequence of PPGHFK was located at 22-27 of the bFGF. The specific immuno-response of mouse could be highly induced by phage clones with the epitopes. And the anti-bFGF activity induced by LPGHFK was 3 times higher than the original sequence, which showed that the mimetic peptide LPLGHIK might be used as a tumor vaccine in the prevention and treatment of tumor.

1차원 가우시안 모델을 이용한 지문 땀샘 추출 방법

최균건(Junjian Cui),나문수(Moonsoo Ra),김회율(Whoi-Yul Kim) 대한전자공학회 2015 전자공학회논문지 Vol.52 No.4

지문의 땀샘(pore)은 지문인식 분야에서 아주 유용한 특징의 하나이고 땀샘에 기반한 지문인식 시스템도 많이 제안되었다. 땀샘 정보를 이용하여 지문을 인식하려면 땀샘을 정확하게 추출하는 것이 아주 중요하다. 기존의 땀샘 추출 방법은 2차원 모델정합 기법을 이용하여 땀샘 중심을 검출한다. 본 논문에서는 2차원 모델보다 간단한 1차원 가우시안 모델을 이용한 땀샘 추출 방법을 제안한다. 1차원 모델을 이용하여 모델정합하는 과정에 2차원 모델보다 적은 연산량을 필요한다는 장점이 있다. 제안하는 방법은 먼저 국부적 융선(ridge)의 방향을 계산하고 융선 마스크(ridge mask)를 생성한 다음 땀샘 중심이 주변보다 밝다는 성질을 이용하여 사이즈가 각각 3 × 3 과 5 × 5인 필터로 땀샘 후보를 찾는다. 검출된 땀샘 후보에 대하여 1차원 가우시간 모델정합을 적용하여 땀샘 중심을 검출한다. 땀샘 추출 실험을 통하여 제안하는 방법은 기존의 2차원 모델에 기반한 방법보다 더 높은 땀샘 검출률을 보여주었고 땀샘 매칭 실험을 통하여 제안하는 땀샘 추출 방법이 지문인식에 사용될 수 있음을 보여준다. Fingerprint pores have proven to be useful features for fingerprint recognition and several pore-based fingerprint recognition systems have been reported recently. In order to recognize fingerprints using pore information, it is very important to extract pores reliably and accurately. Existing pore extraction methods utilize 2D model fitting to detect pore centers. This paper proposes a pore extraction method using 1D Gaussian model which is much simpler than 2D model. During model fitting process, 1D model requires less computational cost than 2D model. The proposed method first calculates local ridge orientation; then, ridge mask is generated. Since pore center is brighter than its neighboring pixels, pore candidates are extracted using a 3 × 3 filter and a 5 × 5 filter successively. Pore centers are extracted by fitting 1D Gaussian model on the pore candidates. Extensive experiments show that the proposed pore extraction method can extract pores more effectively and accurately than other existing methods, and pore matching results show the proposed pore extraction method could be used in fingerprint recognition.

재한 중국유학생의 유학동기와 문화적응에 대한 질적 연구

LUO JUNJIAN 한국사회학회 2021 한국사회학회 사회학대회 논문집 Vol.2021 No.12

DENSITY SMOOTHNESS PARAMETER ESTIMATION WITH SOME ADDITIVE NOISES

Zhao, Junjian,Zhuang, Zhitao Korean Mathematical Society 2018 대한수학회논문집 Vol.33 No.4

In practice, the density function of a random variable X is always unknown. Even its smoothness parameter is unknown to us. In this paper, we will consider a density smoothness parameter estimation problem via wavelet theory. The smoothness parameter is defined in the sense of equivalent Besov norms. It is well-known that it is almost impossible to estimate this kind of parameter in general case. But it becomes possible when we add some conditions (to our proof, we can not remove them) to the density function. Besides, the density function contains impurities. It is covered by some additive noises, which is the key point we want to show in this paper.

중국인 호텔 이용객의 개인특성이 서비스가치 및 브랜드 태도에 미치는 영향

송군검(Song, Junjian),강인호(Kang, Inho) 대한관광경영학회 2018 觀光硏究 Vol.33 No.4

In this study, we studied the impact of Chinese hotel users personal characteristics on service value and brand attitude in order to suggest efficient measures in the hotel industry. Based on this, we will provide useful materials to Chinese tourists visiting Korea to establish their differences and competitiveness as attractive hotels so that they can enjoy satisfaction and continuous visit effects. If the service value is strengthened by understanding the personal characteristics (extraversibility, imputability, and navigation) of Chinese tourists who are visiting Korea, it will help to establish a positive level of food and brand image. This research is of great significance in that it has identified the relationship between hotel customers personal characteristics, service value and brand attitude. However, since most of the subjects were limited to the opinions of young people in their 20s and 30s and Chinese tourists visiting Korea, it could be difficult to generalize them as they represent specific subjects of study and countries. Future studies need to be conducted on a variety of subjects and countries, and more meaningful findings are expected. 본 연구에서는 호텔 산업분야에 효율적인 방안을 제안하고자 방한 중국인 호텔 이용객의 개인특성이 서비스 가치와 브랜드 태도에 미치는 영향에 대해 연구하였다. 이를 바탕으로, 한국을 방문하는 중국관광객에게 만족도와 지속적인 방문 효과를 누릴 수 있도록 매력적인 호텔로서의 차별성과 경쟁력을 확고히 수립하는데 유용한 자료를 제공하고자 한다. 방한 중인 중국 관광객에 대해 개인특성(외향성, 충동성, 도전성)의 가치를 파악해 서비스가치를 강화하면 관광객의 긍정적인 만족도와 브랜드 이미지 수립에 도움이 될 것으로 사료된다. 본 연구는 방한 중국인 관광객의 호텔 이용객의 개인 특성과 서비스 가치, 브랜드 태도의 관계를 규명하였다는 점에서 큰 의의가 있다. 하지만, 연구대상을 대부분 2-30대의 젊은 연령층의 의견과 방한 중국인 관광객으로 한정하였기 때문에 특정 연구 대상 및 대상 국가를 대표하므로 일반화시키기에 무리가 있을 수 있다. 향후 연구에서는 다양한 연구 대상과 국가에 대한 연구가 진행될 필요가 있으며 더욱 의미 있는 연구 결과가 도출될 것을 기대한다.

Random sampling and reconstruction of signals with finite rate of innovation

Yingchun Jiang,Junjian Zhao 대한수학회 2022 대한수학회보 Vol.59 No.2

In this paper, we mainly study the random sampling and reconstruction of signals living in the subspace $V^p(\Phi,\Lambda)$ of $L^p(\mathbb{R}^d)$, which is generated by a family of molecules $\Phi$ located on a relatively separated subset $\Lambda\subset \mathbb{R}^d$. The space $V^p(\Phi,\Lambda)$ is used to model signals with finite rate of innovation, such as stream of pulses in GPS applications, cellular radio and ultra wide-band communication. The sampling set is independently and randomly drawn from a general probability distribution over $\mathbb{R}^d$. Under some proper conditions for the generators $\Phi=\{\phi_\lambda:\lambda\in \Lambda\}$ and the probability density function $\rho$, we first approximate $V^{p}(\Phi,\Lambda)$ by a finite dimensional subspace $V^{p}_N(\Phi,\Lambda)$ on any bounded domains. Then, we prove that the random sampling stability holds with high probability for all signals in $V^{p}(\Phi,\Lambda)$ whose energy concentrate on a cube when the sampling size is large enough. Finally, a reconstruction algorithm based on random samples is given for signals in $V^{p}_N(\Phi,\Lambda)$.

Design and Implementation of Metadata Cache Management Strategy for the Distributed File System

Jingning Liu,Junjian Chen,Wei Tong,Lei Tian,Cong Chen 보안공학연구지원센터(IJGDC) 2014 International Journal of Grid and Distributed Comp Vol.7 No.3

Evaluation of the performance of polymer gels mixed with asphalt particle as a novel composite profile control system

Guangwei Liu,Hanqiao Jiang,Junjian Li,Min Wang,Fuzhen Chen,Shuaiwei Ding,Xiangan Lu 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.26 No.-

This paper presents gels with asphalt particle (GAP) as a novel composite profile control system, which has better sealing effect for plugging channeling in fractured reservoir. This composite agent was prepared by modified asphalt particle and polymer gels served as suspension. Laboratory core–flood tests showed good injectiviy of GAP solution in high permeability zone with a high plugging rate. Also, the enhance oil recovery mechanism of GAP and polymer gels in fractured reservoir were compared by parallel core–flood test. Simulation results indicate longer response time and better enhance oil recovery for GAP than polymer gels in fractured system.