In the context of increasing environmental awareness and resource scarcity, trade-in and remanufacturing have emerged as important strategies for sustainable product management. This study constructs decision-making models for a monopolistic manufacturer operating in a two-period market. The manufacturer produces new products in Period 1, recycles used products via trade-in for remanufacturing, and sells both new and remanufactured products in Period 2. Depending on whether the remanufactured product price is pre-committed, two models (no price commitment and price commitment) are established. The model optimization reveals that, regardless of the price commitment, four recycling and remanufacturing strategies emerge when the manufacturer engages in remanufacturing. The choice of strategy is jointly influenced by the unit residual value of the used product ($s$) and the unit cost of the remanufactured one ($c_r$). The theoretical findings for a special case ($c_r=s=0$) demonstrate that pre-committing the price of remanufactured products compels the manufacturer to simultaneously lower the price of new products and reduce trade-in subsidy while elevating the remanufactured product price. This pricing realignment reduces combined sales volumes across both periods, ultimately diminishing the total profit over two periods. Moreover, price commitment does not boost the remanufacturing rate. This study provides theoretical guidance and managerial insights for manufacturers in terms of pricing strategies and the reuse of used products.

Background: Parental responses to children’s negative emotions (PRCNE) play a crucial role in child development, yet their relationship with children’s purpose in life (CPL) remains underexplored. Given that Chinese parents attach great importance to gender-differentiated child-rearing, it is imperative to investigate gender-based variations in children’s perceptions of PRCNE and their associations with the construction of meaning in CPL. Purpose: This study aimed to investigate: (1) the interconnections among perceived dimensions of PRCNE; (2) the pattern of associations linking perceived PRCNE dimensions to children’s CPL, thereby extending the literature on parental behaviors and child development; and (3) the boundary role of gender by examining gender differences in both the perceived PRCNE patterns and their associations with CPL. Methods: Data were collected from a sample of 573 Chinese students between March and June 2024, and network analysis was conducted. Given the study’s focus on pairwise variable associations, strength centrality and bridge strength were jointly examined to identify key nodes and meaningful connections within the networks. Results: Network comparisons within the PRCNE network revealed that problem-focused response was the most central node among boys (centrality = 1.142), whereas emotion-focused response was the most central node among girls (centrality = 1.085). In the combined PRCNE–CPL network, minimization response emerged as the strongest bridge node and was positively associated with beyond-self orientation (weight = 0.112). While global network structures were invariant across gender, localized differences in specific edge weights suggested that girls’ networks exhibited tighter clustering of negative responses. Furthermore, the assocaition between problem-focused response and meaningfulness was significantly stronger for boys than for girls ( p = 0.034), while the edge between emotion-focused response and goal-directedness appeared only for girls ( p = 0.055). Conclusion: These findings indicate that children’s perceptions of PRCNE reflect a mixed pattern: overall, boys perceived a greater emphasis on problem-solving responses, while girls perceived a greater emphasis on emotional support. Minimization response is positively associated with goal directedness, suggesting it may co-occur with aspects of children’s purpose development. Gender-stratified analyses further revealed that the difference of purpose built between problem-focused response among boys and emotion-focused response girls. These results underscore the importance of perceived PRCNE for children’s development and broaden the research significance of family education.

Point cloud semantic segmentation is a fundamental task for 3D scene understanding. However, acquiring dense point-wise annotations is labor-intensive and expensive. To alleviate the annotation burden, weakly supervised methods using extremely sparse labels (e.g., 0.1%) have attracted increasing attention. While existing methods have demonstrated promising performance, they struggle to generate sufficiently reliable pseudo-labels from unlabeled points, which limits further improvement in segmentation performance under extremely sparse supervision. To address this challenge, we propose a Multi-stage Pseudo-label Guided (MPG) training framework, which mines high-quality pseudo-labels through a two-stage training strategy. In the first stage, we introduce a Prototype-guided Pseudo-label Filter (PPF) to capture latent semantic information by comparing unlabeled features with class prototypes and removes unreliable pseudo-labels using a predefined threshold. In the second stage, we employ a teacher-student architecture and introduce a Pseudo-Label Fusion (PLF) strategy. PLF applies consistency and confidence filtering on two data-augmentation branches of the frozen teacher model to produce refined pseudo-labels, which are then combined with PPF outputs to train the student network. This design allows the student model to inherit distilled knowledge while exploring additional semantic information. Extensive experiments on indoor and outdoor building scenes demonstrate the effectiveness of MPG. Under extremely sparse supervision, MPG achieves 69.5% mIoU on S3DIS and 59.5% on XIAMEN-Buildings, achieving state-of-the-art performance among weakly supervised methods and performance comparable to some fully supervised methods.