A Noisy Videos Background Subtraction Algorithm Based on Dictionary Learning

( Huaxin Xiao ),( Yu Liu ),( Shuren Tan ),( Jiang Duan ),( Maojun Zhang ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.6

Most background subtraction methods focus on dynamic and complex scenes without considering robustness against noise. This paper proposes a background subtraction algorithm based on dictionary learning and sparse coding for handling low light conditions. The proposed method formulates background modeling as the linear and sparse combination of atoms in the dictionary. The background subtraction is considered as the difference between sparse representations of the current frame and the background model. Assuming that the projection of the noise over the dictionary is irregular and random guarantees the adaptability of the approach in large noisy scenes. Experimental results divided in simulated large noise and realistic low light conditions show the promising robustness of the proposed approach compared with other competing methods.

Study of the Correlation Between the Doped-Oxygen Species and the Supercapacitive Performance of TiC–CDC Carbon-Based Material

Yu Gu,Ruijun Zhang,Wenyu Wu,Bin Guo,Ping Wang,Huaxin Ma 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.11

O-doping has proved to be one of the most promising approaches to further enhance the supercapacitive performance of carbon materials. However, it is presently not clear how the type of doped-O species affects the capacitive performance. In this paper, an attempt has been made to probe into the possible correlation between the type of doped-O species and the corresponding capacitive performance. Three O species (C=O, C–O and O–C=O) have been introduced onto TiC-derived carbon (TiC–CDC) by using a facile room-temperature oxidation strategy with three typical oxidizing agents (H2O2, HNO3 and (NH4)-2S2O8), respectively. The results have shown that as the content of the C=O species increases, both the specific capacitance and the capacitance retention for the oxidized TiC–CDC samples become higher, showing a positively correlative performance. This work suggests that optimizing the type of doped-O species will be great potential for obtaining the optimal electrochemical performances for the O-doped carbon materials.

A Multi-Priority Service Differentiated and Adaptive Backoff Mechanism over IEEE 802.11 DCF for Wireless Mobile Networks

( Bo Zheng ),( Hengyang Zhang ),( Kun Zhuo ),( Huaxin Wu ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.7

Backoff mechanism serves as one of the key technologies in the MAC-layer of wireless mobile networks. The traditional Binary Exponential Backoff (BEB) mechanism in IEEE 802.11 Distributed Coordination Function (DCF) and other existing backoff mechanisms poses several performance issues. For instance, the Contention Window (CW) oscillations occur frequently; a low delay QoS guarantee cannot be provided for real-time transmission, and services with different priorities are not differentiated. For these problems, we present a novel Multi-Priority service differentiated and Adaptive Backoff (MPAB) algorithm over IEEE 802.11 DCF for wireless mobile networks in this paper. In this algorithm, the backoff stage is chosen adaptively according to the channel status and traffic priority, and the forwarding and receding transition probability between the adjacent backoff stages for different priority traffic can be controlled and adjusted for demands at any time. We further employ the 2-dimensional Markov chain model to analyze the algorithm, and derive the analytical expressions of the saturation throughput and average medium access delay. Both the accuracy of the expressions and the algorithm performance are verified through simulations. The results show that the performance of the MPAB algorithm can offer a higher throughput and lower delay than the BEB algorithm.

태양광입사면적 증가를 위한 실리콘가공법의 개발

신근식(G. S. Shin),ZHANG HUAXIN,GUO SHANG,권현규(H. K. Kweon),정봉교(B. K. Jeong) 한국정밀공학회 2016 한국정밀공학회 학술발표대회 논문집 Vol.2016 No.10월

An Alkaline pH Control Strategy for Methionine Adenosyltransferase Production in Pichia pastoris Fermentation

Xiaoqing Hu,Ju Chu,Si-Liang Zhang,Ying-ping Zhuang,Xin Wu,Huaxin Chen,Zhongyuan Lv,Zhongyi Yuan 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.5

Pichia pastoris is a successful system forexpressing heterologous proteins and its fermentation pH isalways maintained below 7.0. However, particular proteinsare unstable under acidic conditions, such as methionineadenosyltransferase (MAT), and thus fermentation underacidic pH conditions is unsuitable because protein activityis lost owing to denaturation. Here, a strategy employingalkaline pH in the late fermentation period was developedto improve MAT production. Initially, P. pastoris KM71was transformed with the mat gene to overexpress MAT. After 72 h of in vitro incubation at different pH values, theexpressed MAT displayed highest stability at pH 8.0;however, pH 8.0 inhibited cell growth and induced cellrupture, thus affecting protein production. To balance MATstability and Pichia cell viability, different pH controlstrategies were compared. In strategy A (reference), theinduction pH was maintained at 6.0, whereas in strategy B,it was gradually elevated to 8.0 through a 25 h transitionperiod (80 ~ 105 h). MAT activity was 0.86 U/mg (twofoldhigher than the control). However, MAT content wasreduced by 50% when compared with strategy A, becauseof proteases released upon cell lysis. To improve cellviability under alkaline conditions, glycerol was added inaddition to methanol (strategy C). When compared withstrategy B, the MAT-specific activity remained nearlyconstant, whereas the expression level increased to 1.27 g/L. The alkaline pH control strategy presented herein for MATproduction represents an excellent alternative for expressingproteins that are stable only under alkaline conditions.

A Kalman Filter based Video Denoising Method Using Intensity and Structure Tensor

( Yu Liu ),( Chenlin Zuo ),( Xin Tan ),( Huaxin Xiao ),( Maojun Zhang ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.8

We propose a video denoising method based on Kalman filter to reduce the noise in video sequences. Firstly, with the strong spatiotemporal correlations of neighboring frames, motion estimation is performed on video frames consisting of previous denoised frames and current noisy frame based on intensity and structure tensor. The current noisy frame is processed in temporal domain by using motion estimation result as the parameter in the Kalman filter, while it is also processed in spatial domain using the Wiener filter. Finally, by weighting the denoised frames from the Kalman and the Wiener filtering, a satisfactory result can be obtained. Experimental results show that the performance of our proposed method is competitive when compared with state-of-the-art video denoising algorithms based on both peak signal-to-noise-ratio and structural similarity evaluations.

대학교 기숙사 생활 만족도에 영향을 미치는 요인: G대학 외국인 학생을 중심으로

최준혁,장영,정화흠,주설군,Choi, Jun Hyuk,ZHANG, YING,ZHENG, HUAXIN,ZHU, XUEJUN 서비스사이언스학회 2012 서비스연구 Vol.2 No.2

많은 대학에서 해외 유학생을 유치하기 위해 노력하고 있다. 우리나라의 외국 유학 중에는 지리적으로 가까운 중국학생이 가장 많은 상황이며, 향후에도 지속적으로 증가할 가능성이 있기 때문에 이를 충족시켜 줄 수 있는 다양한 서비스 제공이 필요한 시점이다. 본 연구는 대학 기숙사를 대상으로 하여, 소음요인, 음식요인 및 시설요인이 유학생들의 기숙사 생활만족도에 어떠한 영향을 주는지에 알아보기 위하여, G대학교 중국유학생을 대상으로 실증 연구를 수행하였다. 분석 결과 음식요인과 시설요인은 기숙사 생활 만족도에 유의한(+) 영향을 미치는 것으로 나타났으며, 소음요인은 유의한 영향을 미치지 않은 것으로 나타났다. 연구 결과를 토대로 외국 유학생을 유치하는 대학에서는, 기숙사에 대한 차별화 전략을 사용할 경우 시설 및 음식 요인에 초점을 맞추는 것이 좀 더 효과적이라고 판단된다. Government and many universities have been trying to get the more international students. Foreign students in university are increasing remarkably in Korea. So these authorities have to consider their service competency for new foreign student's living satisfaction. In this paper, we described about the living satisfaction degree on the university dormitory's service in Korea. After reviewing and summarizing the related literatures, our hypotheses are established which the satisfaction be affected by some service factors such as facility, foods, and noise factors in university dormitory's environments. The 99 Chinese students living in G-university dormitory responded to our study. Empirical analysis was performed among a university in Sungnam city named as G-university by using questionnaires sheets. Analysis results are show that satisfaction degree on the university dormitory's service is affected significantly by facility and foods service factors respectively. However noise factor was not the significant variable.