While the international lockdown for the COVID-19 pandemic has greatly influenced the global economy, we are still confronted with the dilemma about the economy recession when the stock market hits record highs repeatedly. As we know, since portfolio selection is often affected by many non-probabilistic factors, it is of not easiness to obtain the precise probability distributions of the return rates. Therefore, fuzzy portfolio model is proposed for solving the efficient portfolio when the economy environment remains in vagueness for the future. To manage such an investment, we revise the Chen and Tsaur’s fuzzy portfolio model by using fuzzy goal programming model. Then, two numerical examples are illustrated by the proposed model which shows that the portfolio selection can be solved by the linguistic imprecise goal of the expected return. With different linguistic descriptions for the imprecise goal of expected return for the future stock market, the optimal portfolio selection that can be solved under different investment risks which is considered better than Chen and Tsaur’s model in real world situations. The sensitivity analysis with some parameter groups can be provided for more invested risk selection in the portfolio analysis.

Smartphones have become indispensable for human beings today. However, with mobile phone manufacturers updating existing models or launching new models every year, consumers tend to keep replacing their phones with the latest versions, resulting in an excessive waste of resources. These days, most governments worldwide emphasize energy conservation and carbon reduction. If pre-owned smartphones are refurbished or repaired, the excessive waste of resources can be reduced. Such recycling can positively enhance corporate image, while ensuring that consumer needs are met. Thus, to explore consumers’ willingness to purchase such “green” smartphones, this study uses the theory of reasoned action (TRA) to explore consumers’ purchase intentions and understand how brand equity, green marketing, as well as consumer’s green awareness and attitude influence this intention. This research also investigates the role of government subsidies as a moderator affecting consumers’ willingness to purchase green smartphones. The results indicate that, in general, consumers are willing to purchase green smartphones, the direct effect of brand equity on purchase intention is significant, and government subsidies have significant moderating effects. Therefore, it is recommended that the government cooperate with enterprises. The cooperation can be aimed at promoting green products as well as subsidizing consumers, to increase their willingness to purchase green smartphones.

Fuzzy portfolio selection has resulted in many researchers to focus on this field. Based on the risk attitudes, this study discusses the risk attitudes in a decision group for portfolio selection. Therefore, we adopt the risk attitudes to describe the experts’ risk preferences and subjective judgments, and then we suppose that the risk seeker considers a higher return for an excess investment based on the selected guaranteed rate of return; the risk averter considers a shortage in investment for the securities whose return rates are smaller than the selected guaranteed rate of return; and finally, the risk neutral pursues the regular return rate. In order to solve the multi-objective return rate functions under the corresponding investment risks, the SMART-ROC weighting method is used to hybridize the multi-objective programming model to a linear programming model for solving the portfolio selection. Finally, we illustrate a numerical example and two risk scenarios to show the optimal portfolio selection under different investment risks. The results show that the proposed model can obtain a more robust portfolio than the compared models under different risk priorities in a decision group.