Explore the vast range of titles available.

Fractional Brownian motion with Hurst exponent H ∈ ( 1 / 2 , 1 ) is a good candidate for modeling financial time series with long-range dependence and self-similarity. The main purpose of this paper is to address the valuation of equity indexed annuity (EIA) designs under the market driven by fractional Brownian motion. As a result, this paper presents an explicit pricing expression for point-to-point EIA design and bounds for the pricing of high-water-marked EIA design. Some numerical examples are given to illustrate the impact of the parameters involved in the pricing problems.

Science and technology-driven small and medium-sized enterprises (SMEs) have emerged as vital players in China’s economic landscape, with unlisted SMEs assuming a significant role. However, these unlisted SMEs face formidable financing challenges, exacerbated by information asymmetry and limited access to diverse funding sources. This research introduces a comprehensive Evaluation Indicator System tailored for unlisted science and technology-based SMEs in Province A, China. Grounded in the Catastrophe Progression Method, this system provides an objective and multidimensional assessment of financing capacity, accounting for factors like innovation, growth, solvency, and regional dynamics. Empirical validation demonstrates the system’s practical relevance, reaffirming its potential as a reliable tool for evaluating financing capacity. The study sheds light on the financing stages of these SMEs, emphasizing the importance of external investment channels, especially for growth-stage enterprises. Bank loans remain the primary financing avenue, underscoring the need for enhanced bank evaluation systems. Policymakers should consider tailored approaches based on SME growth stages to optimize resource allocation and support. By addressing the financing challenges faced by unlisted SMEs and fostering a more supportive environment, this research contributes to unlocking their potential for technological innovation, economic growth, and job creation. It underscores the significance of diverse financing options, the role of external factors, and the need for improved bank evaluation processes to facilitate the growth of these enterprises in the dynamic landscape of knowledge-driven economies.

This paper investigates an optimal dividend and capital injection problem in the dual model with a random horizon. Both fixed and proportional costs from the transactions of capital injection are considered. The objective is to maximize the total value of the expected discounted dividends and the penalized discounted capital injections during the horizon, which is described by the minimum of the time of ruin and an exponential random variable. By the fluctuation theory of Lévy processes, the optimal dividend and capital injection strategy is obtained. We also find that the optimal return function can be expressed in terms of the scale functions of Lévy processes. Besides, numerical examples are studied to illustrate our results.

This study investigates a combined optimal financing, reinsurance and dividend distribution problem for a big insurance portfolio. A manager can control the surplus by buying proportional reinsurance, paying dividends and raising money dynamically. The transaction costs and liquidation values at bankruptcy are included in the risk model. Under the objective of maximising the insurance company's value, we identify the insurer's joint optimal strategies using stochastic control methods. The results reveal that managers should consider financing if and only if the terminal value and the transaction costs are not too high, less reinsurance is bought when the surplus increases or dividends are always distributed using the barrier strategy.

The optimal investment and consumption problem is investigated for an insurance company, which is subject to the payment of high-watermark fee from profit. The objective of insurance company is to maximize the expected cumulated discount utility up to ruin time. The consumption behavior considered in this paper can be viewed as dividend payment of the insurance company. It turns out that the value function of the proposed problem is the viscosity solution to the associated HJB equation. The regularity of the viscosity is discussed and some asymptotic results are provided. With the help of the smooth properties of viscosity solutions, we complete the verification theorem of the optimal control policies and the potential applications of the main result are discussed.

In this paper, ruin problems in the risk model with stochastic premium incomes and stochastic return on investments are studied. The logarithm of the asset price process is assumed to be a Lévy process. An exact expression for expected discounted penalty function is established. Lower bounds and two kinds of upper bounds for expected discounted penalty function are obtained by inductive method and martingale approach. Integro-differential equations for the expected discounted penalty function are obtained when the Lévy process is a Brownian motion with positive drift and a compound Poisson process, respectively. Some analytical examples and numerical examples are given to illustrate the upper bounds and the applications of the integro-differential equations in this paper.[PUBLICATION ABSTRACT]

A quality of life questionnaire specific to sarcopenia (SarQoL®) was successfully developed. There is a huge demand for translation and validation in Chinese. The aim of this study was to translate the SarQoL® into Chinese and investigate its psychometric properties. The translation and cross-cultural adaptation process recommended by the developers of the initial questionnaire was followed. A total of 159 participants were investigated. The translation process consists of five steps: (1) two bilinguals independently translate initial English to Chinese; (2) synthesize the two translations into one; (3) backward translations; (4) expert committee review and (5) test of the pre-final version. The validation consists of three parts: (1) validity (discriminative power, construct validity); (2) reliability (internal consistency, test–retest reliability) and (3) floor and ceiling effects. There was no difficulty in translation process. Regarding the validity, good discriminant validity {quality of life for sarcopenic subjects [35.56 (29.73–42.70)] vs. non-sarcopenic ones [73.22 (60.09–82.90)], p < 0.001} and consistent construct validity [high correlations (spearman’s r) of SarQoL® with generic Short Form-36 version 2 questionnaire (0.250 to 0.824) and EuroQoL-5-Dimension questionnaire (− 0.114 to − 0.823)] were found in SarQoL®. Regarding reliability, high internal consistency (Cronbach’s alpha coefficient was 0.867) and excellent test–retest reliability (intraclass coefficient correlation was 0.997, 95% CI 0.994–0.998) were found. No ceiling/floor effect was reflected. A valid SarQoL® questionnaire is now available for Chinese population. It can provide a better understanding of the sarcopenia disease burden and serve as a therapeutic outcome indicator in research.

The advantage of multimodal transport is that it can deliver the goods to their destination in a reasonable combination of transport modes while ensuring security and punctuality. Multimodal transportation can effectively reduce logistics costs, improve logistics efficiency, and reduce environmental pollution. In the process of multimodal transportation, due to the interference of natural factors (weather, terrain, etc.) and some special human factors, it may have different degrees of impact on the transportation time and transportation safety of different transportation modes. Therefore, when choosing a transportation method, it is necessary to consider the transportation time and transportation safety under the interference. However, the current research on multimodal transport has not considered the impact of external interference on transportation time and transportation safety. Compared with other modes of transportation, external interference has a relatively small impact on railway transportation. Railways can safely deliver goods to their destinations on time. Under the background of China’s huge railway network and advanced heavy-duty technology, this paper establishes a multimodal transport route selection model for considering railway as the core, introduces time penalty cost and damage compensation cost, and takes the lowest comprehensive transportation cost as the model objective under the premise of considering transportation reliability and transportation safety. Finally, taking a multimodal transport network in China as an example, an improved ant colony algorithm is used to solve the model and the results verify the rationality of the model.

Background The cochlear sympathetic system plays a key role in auditory function and susceptibility to noise-induced hearing loss (NIHL). The formation of reactive oxygen species (ROS) is a well-documented process in NIHL. In this study, we aimed at investigating the effects of a superior cervical ganglionectomy (SCGx) on NIHL in Sprague-Dawley rats. Methods We explored the effects of unilateral and bilateral Superior Cervical Ganglion (SCG) ablation in the eight-ten weeks old Sprague-Dawley rats of both sexes on NIHL. Auditory function was evaluated by auditory brainstem response (ABR) testing and Distortion product otoacoustic emissions (DPOAEs). Outer hair cells (OHCs) counts and the expression of α 2A -adrenergic receptor (AR) in the rat cochlea using immunofluorescence analysis. Cells culture and treatment, CCK-8 assay, Flow cytometry staining and analysis, and western blotting were to explore the mechanisms of SCG fibers may have a protective role in NIHL. Results We found that neither bilateral nor unilateral SCGx protected the cochlea against noise exposure. In HEI-OC1 cells, H 2 O 2 -induced oxidative damage and cell death were inhibited by the application of norepinephrine (NE). NE may prevent ROS-induced oxidative stress in OHCs and NIHL through the α 2A -AR. Conclusion These results demonstrated that sympathetic innervation mildly affected cochlear susceptibility to acoustic trauma by reducing oxidative damage in OHCs through the α 2A -AR. NE may be a potential therapeutic strategy for NIHL prevention.

Lots of adrenergic receptors (ARs) are widely present across the auditory pathways and are positioned to affect auditory and vestibular functions. However, noradrenergic regulation in the cochlea has not been well characterized. In this study, a rat model of noise-induced hearing loss was developed to investigate the expression of α2A-adrenergic receptor (AR) after acoustic trauma, then, we investigated the expression of α2A-AR in the developing rat cochlea using immunofluorescence, qRT-PCR, and Western blotting. We found that the expression of α2A-AR significantly increased in rats exposed to noise compared with controls. Immunofluorescence analysis demonstrated that α2A-AR is localized on hair cells (HCs), spiral ganglion neurons (SGNs), and the stria vascularis (SV) in the postnatal developing cochlea from post-natal day (P) 0 to P28. Furthermore, we observed α2A-AR mRNA reached a maximum level at P14 and P28 when compared with P0, while no significant differences in α2A-AR protein levels at the various stages when compared with P0. This study provides direct evidence for the expression of α2A-AR in HCs, SGNs, and the SV of the cochlea, indicating that norepinephrine might play a vital role in hearing function within the cochlea through α2A-AR.