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Automatic modulation recognition (AMR) is a challenging problem in intelligent communication systems and has wide application prospects. At present, although many AMR methods based on deep learning have been proposed, the methods proposed by these works cannot be directly applied to the actual wireless communication scenario, because there are usually two kinds of dilemmas when recognizing the real modulated signal, namely, long sequence and noise. This paper aims to effectively process in-phase quadrature (IQ) sequences of very long signals interfered by noise.

This paper proposes a general model for a modulation classifier based on a two-layer nested structure of long short-term memory (LSTM) networks, called a two-layer nested structure (TLN)-LSTM, which exploits the time sensitivity of LSTM and the ability of the nested network structure to extract more features, and can achieve effective processing of ultra-long signal IQ sequences collected from real wireless communication scenarios that are interfered by noise.

Experimental results show that our proposed model has higher recognition accuracy for five types of modulation signals, including amplitude modulation, frequency modulation, gaussian minimum shift keying, quadrature phase shift keying and differential quadrature phase shift keying, collected from real wireless communication scenarios. The overall classification accuracy of the proposed model for these signals can reach 73.11%, compared with 40.84% for the baseline model. Moreover, this model can also achieve high classification performance for analog signals with the same modulation method in the public data set HKDD_AMC36.

At present, although many AMR methods based on deep learning have been proposed, these works are based on the model’s classification results of various modulated signals in the AMR public data set to evaluate the signal recognition performance of the proposed method rather than collecting real modulated signals for identification in actual wireless communication scenarios. The methods proposed in these works cannot be directly applied to actual wireless communication scenarios. Therefore, this paper proposes a new AMR method, dedicated to the effective processing of the collected ultra-long signal IQ sequences that are interfered by noise.

This section outlines a framework for incorporating Artificial Intelligence (AI) and digital transformation (DT) into education, focusing on how they can transform teaching methods, curriculum development, and academic evaluations. It traces the evolution of AI from rule-based systems to learning technologies, highlighting the move toward education and innovative curricula. The framework considers both the benefits of using AI to improve practices and the challenges it brings, such as issues and the potential for creating a digital divide. This balanced perspective is crucial in shaping how DT is adopted in education, promoting a fair educational environment that harnesses the advancements in AI and DT. Aimed at policymakers, administrators, and educators, this section is a road map for navigating the complexities of integrating technology into education, contributing to an adaptable and enriched landscape.

The purpose of this paper is to analyze long-term institutional causes and consequences of preference falsification by studying the evolution of China’s patriarchal clan system.

The historic study shows that although the clan system was abolished in the Qin dynasty, it re-emerged among high-standing families in the Han dynasty and spread to common people after the Tang dynasty.

The author submits that the clan system was an institutional response to the preference falsification problem that arose due to the dictatorial political institutions first established in the Qin dynasty. It helped people to take collective action by themselves and also opened a back door to influence government decisions. A piece of clear evidence is the co-evolution of the clan system and government personnel system.

In this sense, the clan system probably also helped to prolong the political institutions for 2,000 years.

This is the first institutional study on the clan system in China.

The purpose of this paper is to explore the means for enhancing the image and business legitimacy of a socially discredited industry – pawnbroking in pre-1949 China – are explored. Previous studies suggest companies operating within such industries cannot solely rely on hard marketing strategies “to maximize sales and profits as they do with soaps and shoes” (Davidson, 2003, p. 7). Instead, they must find soft strategies for improving company and industry image and legitimacy.

This research relies on qualitative analysis of historical data and documents.

Soft strategies deployed by Chinese pawnbrokers – such as interpretations, moral value advocacies and institutionalized arrangements – contributed substantially to improving pawnbroking’s image and business legitimacy.

Interconnections among ethical values, image, business legitimacy and select marketing strategies are clarified. The efficacy of historically analyzing previously implemented business strategies and their embedding contexts is discussed.

Strategies Chinese pawnbrokers used to mitigate their previously negative image and boost their business legitimacy suggest strategies current socially disapproved companies can use to improve their image and business legitimacy.

A historical analysis of pre-1949 Chinese pawnbroking can suggest soft marketing strategies for overcoming consumers’ negative company and industry impressions.

The Chinese Government relies heavily on increasing farming scale to address the new challenges facing China’s agricultural development. A basket of polices targeted at increasing farming scale has been issued in recent years thereby resulting to debates over large-scale farming in China. The purpose of this paper is to summarize and highlight the debate over China’s on-going large-scale farming.

This paper contributes to the policy debates over large-scale farming in China by reviewing the existing literature on the positive and negative impacts of large-scale farming on agricultural development, land productivity, and national food security. This paper overviews the different ideas and findings of studies associated with the topic.

The mainstream literature supports the idea that large-scale farming will address the challenges facing China’s agricultural development, while others argue that it crowds out the benefits of small farmers, and raises concerns over inequalities of resources allocation and income distribution, and undermines social stability. While proponents argue that large-scale farming may lead to rise in land productivity, opponents argue that it may result into decrease in land productivity and national grain output.

This paper is a policy review based on existing works. It organizes the different debates over large-scale farming in China, and highlights the key arguments put forward.

Increasing numbers of grandparents are raising their grandchildren because of problems within the parental generation such as drug and alcohol addiction, AIDS, divorce, and unemployment. Yet little is known about how grandparents who “parent” or “co‐parent” then‐grandchildren differ from other grandparents, or the extent to which parenting or co‐parenting grandchildren affects grandparent's psychological, physical, or financial well‐being, or feelings of family solidarity. The purpose of this research is to: (1) compare the characteristics of grandparents who go on to parent or co‐parent their grandchildren to grandparents who do not, and (2) assess the effects of entering the two caregiving arrangements — parenting and co‐parenting — on changes in grandparent's psychological, physical, and financial well‐being, as well as their feelings of family solidarity. The data for this study came from 659 grandparents from the USC Longitudinal Study of Generations (LSG) who participated in at least two consecutive waves of data collection measured at three year intervals between 1985 to 1994: parenting grandparents (N = 12), co‐parenting grandparents (N = 27), and non‐parenting grandparents (N = 620). Analysis of the quantitative data reveals that grandparents who parent or co‐parent their grandchildren tend to be younger and less healthy than non‐parenting grandparents. Contrary to expectation, the data also indicate that there is no statistically significant decline in psychological, physical, or financial well‐being, nor in normative or marital solidarity after grandparents begin to caregive. Although the majority of grandparents show stability or improvement in overall psychological well‐being, some show decline. The qualitative data suggests that the extent to which grandparents can choose their level of involvement in caregiving influences and the age of the grandchild, whether they experience caregiving as positive or negative.

The purpose of this paper is to focus on the emerging phenomenon of medical tourism in the context of Iran from a customer experience management perspective and benchmark of their judgment including positive or negative, of the experience they have achieved of the Iranian health (medical) experience (CE) and suggest scenarios for the improvement of the Iranian customer experience management (CEM).

The research methodologies and research methods that are used in this descriptive-analytical research are based on an inspection of the remarkable literature related to medical tourism and customer experience management. The data gathering instrument is a researcher-made questionnaire based on the variables in the conceptual model extracted from the research literature. The study was conducted from May to August 2019. The population cohort of this study was the foreign patients calling selected Iranian hospitals and the sampling method was a purposive and snowball sample of prospective medical tourists. As the study was conducted throughout Iran, some important hospitals in Iran were selected by stratified sampling Yang et al. (2020b). The sample size and data saturation were 500 participants Lv and Song (2019). The collected data using the questionnaire were analyzed by SPSS software and statistical tests.

According to the results, the customer experience management statistical significance in the task aspect is (p = 0.0523), in the mechanical aspect is (p = 0.0563), in the human aspect is (p = 0.0544). The study showed positive customer experience among the patients who had been treated in the Iranian hospitals.

There is a lack of study that focuses on medical tourism and customer experience management in Iran. Therefore, based on the results of this study, the experience of medical tourists in Iran proved to be positive and satisfying. As little research has been conducted in the area of customer experience management (CEM) in Iranian medical tourism, future researchers can use these valuable results precisely and in more detail to benchmark more accurately the customer experience in all areas of medical and health tourism and other research areas in different aspects of CEM in Iran.

This study aims to extend the application of the quality category approach in rapid fatigue assessment of complex welded structures containing defects under arbitrary loadings, following the investigation of their core data and fatigue assessment procedures based on fracture mechanics.

The analysis methods and procedures for calculating equivalent sizes of semi-elliptic cracks and initial sizes of through-width cracks at the weld toe were developed based on the life equivalence principle. Different stress concentration solutions, i.e. 2D-M_k and 3D-M_k solutions, and different bending ratios were considered. Then, approximate equations were proposed to calculate the crack size under combined stress. In addition, a procedure for calculating the fatigue life by interpolation was proposed and applied to engineering examples.

The fatigue lives of fillet and butt weld joints obtained with the 3D-M_k solution for large L/B are longer than those obtained with the 2D-M_k solution. The results of the fatigue life of the brake unit bracket show that the average error between the proposed approximation equations and the quality category approach is 1.6%.

The quality category and equivalent size curves of different stress concentration solutions under combined membrane and bending stresses are newly added, which further expands the application of the quality category approach. When the proposed fatigue life calculation methods are employed, the remaining life can be quickly derived in addition to the qualitative conclusion on the safety of the structure. These provide the necessary conditions to perform a rapid fatigue assessment adapted to engineering purposes.

In this paper, boric acid was loaded on the surface of expandable graphite (EG), polyvinyl alcohol (PVA) and silane coupling agent (KH550) served as a bridge. The purpose of this study was to improve the flame retardant properties of semi-rigid polyurethane, meanwhile, the mechanical properties of the foam got ameliorated.

PVA was dissolved in hot water. EG was added to this solution. After stirring for 0.5 h at 85°C in ultrasonic agitation, the system was put at room temperature to cool. The silane coupling agent KH550 was added dropwise into the solution system, stirring to fully hydrolyze. Boric acid was added into the system, placing it in an oven at 90°C to dry after filtration. Changing of flame retardant properties and mechanical properties of semi-rigid polyurethane adding modified EG were characterized.

The flame retardant performance of the foam with EG has been improved, whereas the tensile strength decreased with an increase in the content of EG. After adding modified EG, compared to semi-rigid polyurethane with EG, flame retardant performance and tensile strength of the foam improved.

In the study reported here, the surface of EG was modified by boric acid. The modified EG was added into semi-rigid polyurethane foam. The flame retardant performance and tensile strength of the foam after adding modified EG were discussed. Results of this research could benefit in-depth study of the influence of adding modified EG to semi-rigid polyurethane. The study could promote the application of flame-retardant polyurethane foam.

The flame retardant performance and tensile strength of the semi-rigid polyurethane were improved by adding modified EG. The effects of modified EG on the flame retardant performance and tensile strength of semi-rigid polyurethane were discussed in detail.