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Search Results: 1 - 10 of 15991 matches for " Zhiqiang Ren "
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A Programmer-Centric Approach to Program Verification in ATS
Zhiqiang Ren,Hongwei Xi
Computer Science , 2012,
Abstract: Formal specification is widely employed in the construction of high-quality software. However, there is often a huge gap between formal specification and actual implementation. While there is already a vast body of work on software testing and verification, the task to ensure that an implementation indeed meets its specification is still undeniably of great difficulty. ATS is a programming language equipped with a highly expressive type system that allows the programmer to specify and implement and then verify within the language itself that an implementation meets its specification. In this paper, we present largely through examples a programmer-centric style of program verification that puts emphasis on requesting the programmer to explain in a literate fashion why his or her code works. This is a solid step in the pursuit of software construction that is verifiably correct according to specification.
Intelligent Gearbox Diagnosis Methods Based on SVM, Wavelet Lifting and RBR
Lixin Gao,Zhiqiang Ren,Wenliang Tang,Huaqing Wang,Peng Chen
Sensors , 2010, DOI: 10.3390/s100504602
Abstract: Given the problems in intelligent gearbox diagnosis methods, it is difficult to obtain the desired information and a large enough sample size to study; therefore, we propose the application of various methods for gearbox fault diagnosis, including wavelet lifting, a support vector machine (SVM) and rule-based reasoning (RBR). In a complex field environment, it is less likely for machines to have the same fault; moreover, the fault features can also vary. Therefore, a SVM could be used for the initial diagnosis. First, gearbox vibration signals were processed with wavelet packet decomposition, and the signal energy coefficients of each frequency band were extracted and used as input feature vectors in SVM for normal and faulty pattern recognition. Second, precision analysis using wavelet lifting could successfully filter out the noisy signals while maintaining the impulse characteristics of the fault; thus effectively extracting the fault frequency of the machine. Lastly, the knowledge base was built based on the field rules summarized by experts to identify the detailed fault type. Results have shown that SVM is a powerful tool to accomplish gearbox fault pattern recognition when the sample size is small, whereas the wavelet lifting scheme can effectively extract fault features, and rule-based reasoning can be used to identify the detailed fault type. Therefore, a method that combines SVM, wavelet lifting and rule-based reasoning ensures effective gearbox fault diagnosis.
Preparation and characterization of a lipoid adsorption material and its atrazine removal performance

Zhiqiang Chen,Qinxue Wen,Jiaxiang Lian,Nanqi Ren,

环境科学学报(英文版) , 2011,
Abstract: A novel adsorbent named lipoid adsorption material (LAM),with a hydrophobic nucleolus (triolein) and a hydrophilic membrane structure (polyamide),was synthesized to remove hydrophobic organic chemicals (HOCs) from solution.Triolein,a type of lipoid,was entrapped by the polyamide membrane through an interfacial polymerization reaction.The method of preparation and the structure of the LAM were investigated and subsequent experiments were conducted to determine the characteristics of atrazine (a type of HOC) removal from wastewater using LAM as the adsorbent.The results showed that LAM had a regular structure compared with the prepolymer,where compact particles were linked with each other and openings were present in the structure of the LAM in which the fat drops formed from triolein were entrapped.In contrast to the atrazine adsorption behavior of powdered activated carbon (PAC),LAM showed a persistent adsorption capacity for atrazine when initial concentrations of 0.57,1.12,8.31 and 19.01 mg/L were present,and the equilibrium time was 12 hr.Using an 8 mg/L initial concentration of atrazine as an indicator of HOCs in aqueous solution,experiments on the adsorption capacity of the LAM showed 69.3% removal within 6-12 hr contact time,which was close to the 75.5%removal of atrazine by PAC.Results indicated that LAM has two atrazine removal mechanisms,namely the bioaccumulation of atrazine by the nucleous material and physical adsorption to the LAM membrane.Bioaccumulation was the main removal mechanism.
Multi-mark: Multiple Watermarking Method for Privacy Data Protection in Wireless Sensor Networks
Baowei Wang,Xingming Sun,Zhiqiang Ruan,Heng Ren
Information Technology Journal , 2011,
Abstract: To achieve a more comprehensive and sustained privacy control and tamper detection for the data in wireless sensor networks, we propose a novel multiple watermarking method, called Multi-mark, which consists of an annotation part and a fragile part. On the one hand, encrypted user’s personal information is embedded into the routine monitoring data, as annotation watermark, which can be extracted when, needed. On the other hand, tampering is detected using fragile watermark. The former can resist various manipulative attacks, while the latter can detect any malicious modifications. Multi-mark not only provides privacy and security, but also saves data transmission amount and storage space. The experimental results show that Multi-mark can reduce 30% of data traffic and only introduces very low computation cost. Multi-mark is a network structure-free scheme, which can be easily and efficiently applied to the resource limited sensor networks.
An Efficient Scheme Against Node Capture Attacks using Secure Pairwise Key for Sensor Networks
Heng Ren,Xingming Sun,Zhiqiang Ruan,Baowei Wang
Information Technology Journal , 2011,
Abstract: In this study, we aim to design an efficient scheme against node capture attacks using secure pairwise key in Wireless Sensor Networks (WSNs). Prior pairwise key establishment schemes based on random key pre-distribution are vulnerable to node capture attacks. In order to improve the resilience against node capture attacks, we are the first to present the Key Superset (KS) scheme. In this scheme, the entire sensor network is devided into several non-overlapping triangle cells and nodes are separated into groups, each of which is deployed in a cell and each pair of adjacent cells selects randomly a certain number of keys from the key subset which belongs to the key superset. By using deployment knowledge and KS scheme we can restrict the consequence of node capture attacks within a small range and establish pairwise key for each pair of neighboring cells efficiently. Compared to existing schemes, our proposal outperforms others in resilience against node capture attacks and achieves high local connectivity.
Performance Evaluation Method and Algorithm of Knowledge Management for Product Innovation Design
Yongdang Chen,Huijuan Ren,Zhiqiang Bao,Guangmei Liu
International Journal of Online Engineering (iJOE) , 2013, DOI: 10.3991/ijoe.v9is2.2604
Abstract: This paper presents a discussion of knowledge management performance evaluation index and evaluation methods for product innovation. The content of knowledge management and the flow of knowledge in product innovation process are analyzed. According to the purpose of performance evaluation and combined with the characteristics of product innovation, the knowledge management performance index for product innovation is established, and the specific evaluation method and algorithm are described. The fuzzy comprehensive evaluation process is discussed.
A DNA Sequence Compression Algorithm Based on LUT and LZ77
Sheng Bao,Shi Chen,Zhiqiang Jing,Ran Ren
Mathematics , 2005,
Abstract: This article introduces a new DNA sequence compression algorithm which is based on LUT and LZ77 algorithm. Combined a LUT-based pre-coding routine and LZ77 compression routine,this algorithm can approach a compression ratio of 1.9bits \slash base and even lower.The biggest advantage of this algorithm is fast execution, small memory occupation and easy implementation.
Research on Industry Leaders’ External Auditing Demand in China—Based on the Signal Transfer Theory  [PDF]
Zhiqiang Wen
Open Journal of Business and Management (OJBM) , 2016, DOI: 10.4236/ojbm.2016.41013
Abstract: This paper validates the demand for audit’s signal transfer theory by China’s A-share listed company data. As having a significant influence on the region and the industries where they locate in, industry leaders will catch more attention. In this case, compared to other companies, industry leaders have stronger demands for high-quality audit services, because it can transmit a signal to the market that they are under a good company supervision. However, high growth industry leaders don’t have a stronger demand for high quality audit services than other ones as we refer in the hypothesis. The reason is that even industry leaders do not have external financing needed, they will still choose high-quality audit services, as it can transfer a good signal to the outside world.
Bulking sludge for PHA production:Energy saving and comparative storage capacity with well-settled sludge
Qinxue Wen,Zhiqiang Chen,Changyong Wang,Nanqi Ren,
Qinxue Wen
,Zhiqiang Chen,Changyong Wang,Nanqi Ren

环境科学学报(英文版) , 2012,
Abstract: Two acetate-fed sequencing batch reactors (SBR) were operated under an aerobic dynamic feeding (ADF) model (SBR #2) and with anaerobic phase before aerobic phase (SBR #1) to select mixed cultures with a high polyhydroxyalkanoates (PHA) storage response. Although kinetic selection based on storage response should bring about a predominance of floc-formers, a bulking sludge with storage response comparable to well-settled sludge was steadily established. An anaerobic phase was introduced before the aerobic phase in the ADF model to improve the sludge settleability (SBR #1), however, due to the consequent increased feast/famine ratio, the performance of SBR #1, in terms of both the maximum PHB (polyhydroxybutyrate) cell content and ΔPHB, was lower than that of SBR #2. SBR #2 gradually reached a steady state while SBR #1 failed suddenly after 50 days of operation. The maximum specific substrate uptake rate and storage rate for the selected bulking sludge were 0.4 Cmol Ac/(Cmol X.hr) and 0.18 Cmol Ac/(Cmol PHB.hr), respectively, resulting a yield of 0.45 Cmol PHB/(Cmol Ac) in SBR #2 in the culture enrichment phase. A maximum PHB content of 53% of total suspended solids and PHB storage rate of 1.36 Cmol Ac/(Cmol PHB.hr) was achieved at 10.2 hr in batch accumulation tests under nitrogen starvation. The results indicated that it was feasible to utilize filamentous bacteria to accumulate PHA with a rate comparable to well-settled sludge. Furthermore, the lower dissolved oxygen demand of filamentous bacteria would save energy required for aeration in the culture enrichment stage.
INFLUENCE OF ELECTROMAGNETIC STIRRING ON MACROSEGREGATION OF CAST IRON
CAO Zhiqiang ZHANG Liping REN Zhongming JIN Junze Dalian University of Technology,Dalian,China,
CAO Zhiqiang ZHANG Liping REN Zhongming JIN Junze Dalian University of Technology
,Dalian,China

金属学报(英文版) , 1992,
Abstract: Enrichment of massive graphite on lateral surface and evident macrosegregation along both longitudinal and axial directions were found by the influence of intense electromag- netic stirring during unidirectionally solidifying grey cast iron ingot.A secondary flow within the region near solidliquid interface seems to be the cause of axial segregation, and the solidification rate may also be influential in the macrosegregation.
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