Establishment of Knowledge Base for Decision-making of Handling Process for Port Heavy Lift Cargoes

Xiaofeng Gu,Youfang Huang,Ting Fang,Wei Yan,Junliang He 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.6

Game Analysis in the Sharing Process of Enterprise-type Customer Knowledge

Wei Hongmei,Ju Xiaofeng 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

Enterprise-type customer knowledge crucially influences the development of the enterprise, but the sharing process and the sharing conditons of it is diverse due to the difference of the position of enterprise-type customer in the supply chain. Hence, this paper respectively adopts the dynamic game of complete information and that of incomplete information to analyze the sharing process of different enterprise-type customer knowledge. Moreover, the backward induction of dynamic programming is used to solve the sub-game perfect equilibrium so that the sharing conditions of enterprise-type custmoer knowledge are obtained. The research results show that it mainly depends on the prior probability that cumtomer knowledge is valuable and the charge for sharing knowledge whether the enterprise-type customer as the final consumer share its knowledge with the enterprise; on the other hand, the relationship among the cost of self-study, the cost of knowledge sharing and distribution proportion of income becomes the crucial factor affecting the knowledge sharing between the enterprise-type customer who is not the final consumer and the enterprise.

Fuzzy system and Improved APIT (FIAPIT) combined range-free localization method for WSN

( Xiaofeng Li ),( Liangfeng Chen ),( Jianping Wang ),( Zhong Chu ),( Qiyue Li ),( Wei Sun ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.7

Among numerous localization schemes proposed specifically for Wireless Sensor Network (WSN), the range-free localization algorithms based on the received signal strength indication (RSSI) have attracted considerable research interest for their simplicity and low cost. As a typical range-free algorithm, Approximate Point In Triangulation test (APIT) suffers from significant estimation errors due to its theoretical defects and RSSI inaccuracy. To address these problems, a novel localization method called FIAPIT, which is a combination of an improved APIT (IAPIT) and a fuzzy logic system, is proposed. The proposed IAPIT addresses the theoretical defects of APIT in near (it`s defined as a point adjacent to a sensor is closer to three vertexes of a triangle area where the sensor resides simultaneously) and far (the opposite case of the near case) cases partly. To compensate for negative effects of RSSI inaccuracy, a fuzzy system, whose logic inference is based on IAPIT, is applied. Finally, the sensor`s coordinates are estimated as the weighted average of centers of gravity (COGs) of triangles` intersection areas. Each COG has a different weight inferred by FIAPIT. Numerical simulations were performed to compare four algorithms with varying system parameters. The results show that IAPIT corrects the defects of APIT when adjacent nodes are enough, and FIAPIT is better than others when RSSI is inaccuracy.

Scheduling Optimization of Prefabricated Buildings under Resource Constraints

Wei He,Wenjing Li,Xiaofeng Meng 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.12

Different from traditional construction project management, the prefabricated building (PB) engineering has a complicated restricted relationship in scheduling scheme, and the entire project is accomplished by multi-stage collaboration in construction process. Consequently, it is of great importance for project managers to make reasonable resources scheduling to avoid disruptions caused by resource unavailability. However, the poor interoperability and interactivity still results in diverse constraints, which limit the PB construction progress. Therefore, the aim of this paper is to establish a PB resource scheduling model that satisfying resource constraints and strengthening the PB dispatch time connection. The PB construction process is divided into assembly work space, logistics work space, and production work space where the construction time note is regarded as connection constraint and the three work spaces are restrained mutually. What’s more, the optimal total amount of resources determination technology is presented to arrange the resource schedule in assembly work space to ensure the optimal resource quantity with the goals of the shortest construction time and the lowest cost. The dynamic scheduling coordination technology is put forward to logistics work space and production work space where the resource schedule is arranged with time node constraint. A high-rise building is presented as an example to illustrate the implementation of the proposed model. Results show that the presented method could effectively solve the problem of resource tension problem under the goal of the lowest cost as well as alleviate the shortage of multi-resource scheduling.

Lithium-ion battery state of charge and parameters joint estimation using cubature Kalman filter and particle filter

Xu, Wei,Xu, Jinli,Yan, Xiaofeng The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.1

Accurate estimation of the state of charge (SOC) of a lithium-ion battery is one of the most crucial issues of battery management system (BMS). Existing methods can achieve accurate estimation of the SOC under stable working conditions. However, they may result in inaccuracy under unstable working conditions such as dynamic cycles and different temperature conditions. This is due to the fact that the dynamic behaviors of battery states have not been considered by the parameter identification methods. In this paper, a SOC and parameter joint estimation method is put forward, where the battery model parameters are identified in real time by a particle filter (PF) with consideration of the battery states. Meanwhile, a cubature Kalman filter (CKF) is used to estimate SOC. Then, experiments under dynamic cycles and different temperature conditions are undertaken to assess the performance of the proposed algorithm when compared with the existing joint estimations. The results show that the proposed joint method can achieve a high accuracy and robustness for SOC estimation.

<i>In Situ</i> Observation and Electrochemical Study of Encapsulated Sulfur Nanoparticles by MoS₂ Flakes

Tang, Wei,Chen, Zhongxin,Tian, Bingbing,Lee, Hyun-Wook,Zhao, Xiaoxu,Fan, Xiaofeng,Fan, Yanchen,Leng, Kai,Peng, Chengxin,Kim, Min-Ho,Li, Meng,Lin, Ming,Su, Jie,Chen, Jianyi,Jeong, Hu Young,Yin, Xuesong American Chemical Society 2017 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.139 No.29

<P>Sulfur is an attractive cathode material for next-generation lithium batteries due to its high theoretical capacity and low cost. However, dissolution of its lithiated product (lithium polysulfides) into the electrolyte limits the practical application of lithium sulfur batteries. Here we demonstrate that sulfur particles can be hermetically encapsulated by leveraging on the unique properties of two-dimensional materials such as molybdenum disulfide (MoS<SUB>2</SUB>). The high flexibility and strong van der Waals force in MoS<SUB>2</SUB> nanoflakes allows effective encapsulation of the sulfur particles and prevent its sublimation during <I>in situ</I> TEM studies. We observe that the lithium diffusivities in the encapsulated sulfur particles are in the order of 10<SUP>–17</SUP> m<SUP>2</SUP> s<SUP>–1</SUP>. Composite electrodes made from the MoS<SUB>2</SUB>-encapsulated sulfur spheres show outstanding electrochemical performance, with an initial capacity of 1660 mAh g<SUP>–1</SUP> and long cycle life of more than 1000 cycles.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2017/jacsat.2017.139.issue-29/jacs.7b05371/production/images/medium/ja-2017-05371c_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja7b05371'>ACS Electronic Supporting Info</A></P>

Representing the Heat-to-Moisture Transport Efficiency in Stable Conditions: An Extension of Two Different Approaches

Guo Xiaofeng,Yang Kun,Yang Wei,Zhao Long,Li Shenghai,Ding Baohong 한국기상학회 2020 Asia-Pacific Journal of Atmospheric Sciences Vol.56 No.4

Using eddy-covariance turbulence measurements over a Tibetan glacier, we present a description of scalar turbulence characteristics in the stable boundary layer. Interesting behaviours are demonstrated in terms of temperature–humidity de-correlation and dissimilarity. That is, a lack of perfect correlation occurs between the two scalars (i.e., correlation coefficients <1 in magnitude); overall, sensible heat is more efficiently transported than water vapour over snow and ice surfaces. Such behaviours provide evidence of departures from the idealized expectation of Monin–Obukhov similarity theory—all scalars assume a perfect level of linear correlation and an equal efficiency level of vertical transport. Results presented herein are noteworthy in that observations over uniform glaciated surfaces involve negligible effects of either a canopy-induced roughness sublayer or heterogeneity in the temperature–humidity source/sink distributions. Moreover, we address two different approaches to representing the heat-to-moisture transport efficiency in stable conditions. A new approach is extended through application of the quadrant analysis technique, thereby representing it as a function of atmospheric stability. Caution is further advised in the use of this approach, when temperature–humidity turbulence becomes markedly de-correlated. A second approach, as previously applied for estimating forest evaporation fluxes in unstable conditions, is extended to a stable boundary layer over snow and ice surfaces.

New receipt-free voting scheme using double-trapdoor commitment

Chen, Xiaofeng,Wu, Qianhong,Zhang, Fangguo,Tian, Haibo,Wei, Baodian,Lee, Byoungcheon,Lee, Hyunrok,Kim, Kwangjo Elsevier 2011 Information sciences Vol.181 No.8

<P><B>Abstract</B></P><P>It is considered to be the most suitable solution for large scale elections to design an electronic voting scheme using blind signatures and anonymous channels. Based on this framework, Okamoto first proposed a receipt-free voting scheme <ce:cross-ref refid='b0150'>[30]</ce:cross-ref> for large scale elections. However, in the following paper, Okamoto <ce:cross-ref refid='b0155'>[31]</ce:cross-ref> proved that the scheme <ce:cross-ref refid='b0150'>[30]</ce:cross-ref> was not receipt-free and presented two improved schemes. One scheme requires the help of the parameter registration committee and the other needs a stronger physical assumption of the voting booth. In this paper, we utilize the double-trapdoor commitment to propose a new receipt-free voting scheme based on blind signatures for large scale elections. Neither the parameter registration committee nor the voting booth is required in our scheme. We also present a more efficient zero-knowledge proof for secret permutation. Therefore, our scheme is much more efficient than Okamoto’s schemes <ce:cross-refs refid='b0150 b0155'>[30,31]</ce:cross-refs> with the weaker physical assumptions. Moreover, we prove that our scheme can achieve the desired security properties.</P>

Synthesis and properties of amino acid functionalized water-soluble perylene diimides

Yongshan Ma,Xuemei Li,Xiaofeng Wei,Tianyi Jiang,Junsen Wu,Huixue Ren 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.7

We prepared amino acid functionalized water-soluble perylene diimides: N,N'-bi(L-glutamic acid)-perylene- 3,4;9,10-dicarboxylic diimide (1), N,N'-bi(L-phenylalanine acid)-perylene-3,4;9,10-dicarboxylic diimide (2), N,N'-bi(Lglutamic amine)-perylene-3,4;9,10-dicarboxylic diimide (3) and N,N'-bi(L-phenylalanine amine)-perylene-3,4;9,10- dicarboxylic diimide (4). The structures of 3 and 4 were confirmed by 1H NMR, FT-IR and MS. The maximal absorption bands of compound 1 and 2 in concentrated sulfuric acid were red-shifted for about 48 and 74 nm, respectively, compared with that of Perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA). Nearly no fluorescence was observed for compounds 1 and 2 in water, while compounds 3 and 4 were significantly water-soluble and had very high fluorescent quantum. The mechanism of the optical properties change was discussed, and the π-π stacking caused by H+ led to the changes of fluorescence spectrum and absorption spectrum. The calculated molecular orbital energies and the frontier molecular orbital maps of compounds 1-2 based on density function theory (DFT) calculations were reported. Owing to the high water-soluble, the perylene derivatives 3 and 4 were successfully applied as high-performance fluorochromes for living hela cells imaging.

An expanded Matrix Factorization model for real-time Web service QoS prediction

( Jinsheng Hao ),( Guoping Su ),( Xiaofeng Han ),( Wei Nie ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.11

Real-time prediction of Web service of quality (QoS) provides more convenience for web services in cloud environment, but real-time QoS prediction faces severe challenges, especially under the cold-start situation. Existing literatures of real-time QoS predicting ignore that the QoS of a user/service is related to the QoS of other users/services. For example, users/services belonging to the same group of category will have similar QoS values. All of the methods ignore the group relationship because of the complexity of the model. Based on this, we propose a real-time Matrix Factorization based Clustering model (MFC), which uses category information as a new regularization term of the loss function. Specifically, in order to meet the real-time characteristic of the real-time prediction model, and to minimize the complexity of the model, we first map the QoS values of a large number of users/services to a lower-dimensional space by the PCA method, and then use the K-means algorithm calculates user/service category information, and use the average result to obtain a stable final clustering result. Extensive experiments on real-word datasets demonstrate that MFC outperforms other state-of-the-art prediction algorithms.