苏联“构成主义”建筑运动的旗手:维斯宁兄弟

维斯宁兄弟是苏联"构成主义"建筑运动的旗手。1922年,兄弟三人联手,支持先锋的艺术观念,并且独创出一种现代建筑流派。1933年,列奥尼德·维斯宁逝世。此后,维克多依然保持了成功的职业生涯。而亚历山大渐渐退出了公开的职业活动。     

An efficient four points modified explicit group poisson solver

In this paper, wc introduce a four points modified explicit group method for solving a two dimensional Poisson equation with Dirichlet boundary condition. The method is shown to be superior compared to the existing four points–explicit group and explicit decoupled group methods due to D. J. Evans and M. J. Biggins (1982) and A. R. Abdullah (1991), respectively, Some experiment results of the test problem are given in order to confirm our claim.     

Influence of group configuration on online discourse writing

This study examines the impact of different strategies for grouping students in online, discourse-intensive distance education courses. The mixed methods research focused on note writing productivity (based on 366 participants in 25 classes) and participants' perceptions (12 graduate students and 10 instructors) relating to three different class configurations (large whole class, small whole class, large class divided into subgroups). Each configuration exhibited advantages and disadvantages in terms of supporting note writing, however, the data analyses suggested that the advantages for writing in subgroups outweighed those of the other two conditions. Splitting larger classes into smaller subgroups appears to reduce information overload and encourages more focused, in-depth discussions. The research concludes with a list of pedagogical recommendations and suggests new software features that may help learning within specific group configurations. This study may have implications for both practitioners and researchers who wish to promote more fruitful online discussions.     

Discovery and representation of the preferences of automatically detected groups: Exploiting the link between group modeling and clustering

There are types of information systems, like those that produce group recommendations or a market segmentation, in which it is necessary to aggregate big amounts of data about a group of users in order to filter the data. Group modeling is the process that combines multiple user models into a single model that represents the knowledge available about the preferences of the users in a group. In group recommendation, group modeling allows a system to derive a group preference for each item. Different strategies lead to completely different group models, so the strategy used to model a group has to be evaluated in the domain in which the group recommender system operates. This paper evaluates group modeling strategies in a group recommendation scenario in which groups are detected by clustering the users. Once users are clustered and groups are formed, different strategies are tested, in order to find the one that allows a group recommender system to get the best accuracy. Experimental results show that the strategy used to build the group models strongly affects the performance of a group recommender system. An interesting property derived by our study is that clustering and group modeling are strongly connected. Indeed, the modeling strategy takes the same role that the centroid has when users are clustered, by producing group preferences that are equally distant from the preferences of every user. This “continuity” among the two tasks is essential in order to build accurate group recommendations.     

Characterization by Stm and Electrical Conductivity of Single-Walled Carbon Nanotubes

Abstract

Single-walled carbon nanotubes (SWCNT) prepared by a DC-Arc-Discharge and purified by a hydrothermal treatment followed by several steps of procedures including heating, burning, extracting and acid-washing are investigated by a conventional STM technique morphologically and spectroscopically. The electical resistivities of compacted pellets (mats) of SWCNT are measured as a function of temperature in the range from the room-temperature to 1.5K. The behaviors seems to be essentially originated in the metallic nature of individual SWCNT.     

Discussion on lower coal group＇s mining condition above aquifer in Sihe coalfield,Jincheng

以山西沁水煤田寺河矿区为工程背景,依托水文地质补充勘探数据,从研究奥陶系峰峰组顶部岩层的阻水能力出发,论证了矿区内相对隔水层的存在性,最后通过流固耦合数值模拟研究证明了相对隔水层存在时,下组煤带压开采条件得到明显改善。因此研究下组煤带压开采条件的关键因素之一是确定奥陶系顶部岩组本身是否具备较好的阻水能力。     

“I’ll have what he’s having”: Group ordering behavior in food choice decisions

Current research has focused on whether nutrition labeling and pricing policies (e.g., soda taxes) influence food decisions; however, less attention has been given to how peers influence one’s food decisions. This study uses sales receipts from a full-service restaurant to take a closer look at how people order in groups. Results of the study revealed people may be less variety-seeking than previous research suggests; in fact, diners were more likely to seek variety when choosing an individual item, but not when choosing a menu category. In other words, diners wanted to be different from their dining companions, but not too different. This result was further confirmed with a model of food choice which shows diners derived more utility from an entrée when a fellow diner ordered an entrée in the same category. Interestingly, the presence of calorie labels on menus did not change the marginal utility of calories, suggesting peer effects may outweigh the effects of nutritional information.     

An approach to group decision making with heterogeneous incomplete uncertain preference relations

For practical group decision making problems, decision makers tend to provide heterogeneous uncertain preference relations due to the uncertainty of the decision environment and the difference of cultures and education backgrounds. Sometimes, decision makers may not have an in-depth knowledge of the problem to be solved and provide incomplete preference relations. In this paper, we focus on group decision making (GDM) problems with heterogeneous incomplete uncertain preference relations, including uncertain multiplicative preference relations, uncertain fuzzy preference relations, uncertain linguistic preference relations and intuitionistic fuzzy preference relations. To deal with such GDM problems, a decision analysis method is proposed. Based on the multiplicative consistency of uncertain preference relations, a bi-objective optimization model which aims to maximize both the group consensus and the individual consistency of each decision maker is established. By solving the optimization model, the priority weights of alternatives can be obtained. Finally, some illustrative examples are used to show the feasibility and effectiveness of the proposed method.     

Deriving the priority weights from hesitant multiplicative preference relations in group decision making

In this paper, we investigate the deviation of the priority weights from hesitant multiplicative preference relations (HMPRs) in group decision-making environments. As basic elements of HMPRs, hesitant multiplicative elements (HMEs) usually have different numbers of possible values. To correctly compute or compare HMEs, there are two principles to normalize them, i.e., the α-normalization and the β-normalization. Based on the α-normalization, we develop a new goal programming model to derive the priority weights from HMPRs in group decision-making environments. Based on the β-normalization, a consistent HMPR and an acceptably consistent HMPR are defined, and their desired properties are studied. A convex combination method is then developed to obtain interval weights from an acceptably consistent HMPR. This approach is further extended to group decision-making situations in which the experts evaluate their preferences as several HMPRs. Finally, some numerical examples are provided to illustrate the validity and applicability of the proposed models.     

Group IVB metallocene polyesters containing camphoric acid and preliminary cancer cell activity

Polyesters were formed from the reaction of the salt of camphoric acid and Group IVB metallocene dichlorides using the interfacial polycondenzation process. The polyesters were formed in good yields with moderate chain lengths. Fourier transform infrared spectroscopy shows bands characteristic of the presence of both reactants with new bands characteristic of the formation of the M?O and M–O(CO) linkage present. The polymers largely exist in a bridging geometry of the carbonyl groups about the metal atom. Nuclear magnetic resonance shows the presence of bands derived from both reactants. Matrix-assisted laser desorption/ionization mass spectroscopy shows ion fragments to three units for the polymers with isotopic abundance characteristic of the presence of metal atoms in the ion fragment clusters. All the polymers exhibit good ability to inhibit all the tested cancer cell lines but the zironocene and hafnocene polymers exhibit especially good inhibition of the tested cancer cell lines that included two pancreatic cancer cell lines. They represent a potential new group of anticancer drugs.