O ptimizing advertising budget allocation in the luxury fashion industry is an important problem. In this study, motivated by real-world practices, we consider a luxury fashion firm serving a conspicuous market consisting of two groups of consumers who influence one another. We investigate the optimal customer portfolios and budget allocation problem using the mean-variance (MV) framework. Under the basic model in which all budget must be spent, we identify different scenarios and propose an algorithm to construct the MV efficient frontier for each scenario. Interestingly, different from the classic investment portfolio problem, we reveal that: (i) not all budget allocations between the two groups of consumers are MV efficient, which means that the efficient frontier is not continuous; (ii) in the presence of social influence, diversification of customer portfolio does not always lead to a smaller variance, which counterintuitively means that focusing on a single consumer group can reduce risk. We also prove that to maximize expected profit, the optimal strategy is to allocate all advertising budget to one group of consumers only (i.e., a polarized strategy). We illustrate analytically, the importance of identifying the right scenario for budget planning. Finally, we examine the budget saving strategy in the extended model and uncover that the respective range of efficient solutions is smaller than the one under the all budget spending strategy. This shows that the budget saving strategy offers less flexibility for MV efficient budget allocation than the all budget spending strategy.

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Chili anthracnose caused by Colletotrichum spp. is an annual production concern for growers in China. Sterol C14-demethylation inhibitors (DMIs, such as tebuconazole) have been widely used to control this disease for more than three decades. In the current study, of 48 isolates collected from commercial chili farms in Jiangsu Province of China during 2018 and 2019, 8 single-spore isolates were identified as Colletotrichum gloeosporioides and the rest were identified as C. acutatum. To determine whether the DMI resistance of isolates develops in the field, mycelial growth of the 48 isolates was measured in culture medium with and without tebuconazole. In all, 6 of the 8 C. gloeosporioides isolates were resistant to tebuconazole, but all 40 of the C. acutatum isolates were sensitive to tebuconazole. The fitness cost of resistance was low based on a comparison of fitness parameters between the sensitive and resistant isolates of C. gloeosporioides. Positive cross-resistance was observed between tebuconazole and difenconazole or propiconazole, but not prochloraz. Alignment results of the CgCYP51 amino acid sequences from the sensitive and resistant isolates indicated that mutations can be divided into three genotypes. Genotype I possessed four substitutions (V18F, L58V, S175P, and P341A) at the CgCYP51A gene but no substitutions at CgCYP51B, while genotype II had five substitutions (L58V, S175P, A340S, T379A, and N476T) at CgCYP51A, concomitant with three substitutions (D121N, T132A, and F391Y) at CgCYP51B. In addition, genotype III contained two substitutions (L58V and S175P) at CgCYP51A, concomitant with one substitution (T262A) at CgCYP51B. Molecular docking models illustrated that the affinity of tebuconazole to the binding site of the CgCYP51 protein from the resistant isolates was decreased when compared with binding site affinity of the sensitive isolates. Our findings provide not only novel insights into understanding the resistance mechanism to DMIs, but also some important references for resistance management of C. gloeosporioides on chili.

Virtual Reality (VR) is an advanced, human-computer interface that simulates a realistic environment. The participants can move around in the virtual world. They can see it from different angles, reach into it, grab it and reshape it. There is no little screen of symbols for manipulation nor commands to be entered to get the computer to do something.The term "virtual reality" is credited to Jaron Lanier, who was the founder of VPL Research. The term cyberspace was coined by William Gibson in his 1984 science fiction novel, Neuromancer. Cyperspace is thought of as the ultimate virtual reality environment. It is an alternative computer universe where data exists like cities of light. Information workers use a special virtual reality system to enter cyberspace and to travel its data highways. This gives them the experience of being physically free to go anywhere.Virtual reality feeds off a variety of fields. It is more a convergence of previously aisparate disciplines than a whole new branch of technology. Virtual reality involves electronic and mechanical engineering, cybernetics, database design, real-time and distributed systems, simulation, computer graphics, human engineering, stereoscope, human anatomy and, even, artificial life. The many challenges for creating virtual reality systems include: software, hardware, human factors and VR over high-speed networks.

As with the huge number of deaf-mute people in China is of concern, there is a growing need to integrate them into mainstream society through the use of efficient sign language processing technologies. Sign language processing entails the systematic recognition and translation of sign language images/videos to text or speech. This survey provides an overview of the most important work on Chinese sign language recognition and translation, discussed its classification, highlights the features explored in sign language recognition research, presents the datasets available, and provides trends for the future research.