Dual active bridge converters are widely applied to bidirectional power conversion systems. In this paper, aiming at the slow dynamic response of traditional proportional integral control and the contradiction between current stress and starting speed, a start control strategy based on deadbeat is proposed. Firstly, the working state of single phase shift (SPS) and extended phase shift (EPS) control of DAB converter is analyzed, the output voltage model is obtained. A startup optimization strategy based on deadbeat is proposed for the existing model predictive control methods. Then the steady-state control is switched to SPS control to reduce the complexity of system control. Finally, the simulation results on PSCAD software show the superiority of the proposed method. Compared with the traditional control strategy, the proposed method can achieve fast startup and significantly improve the dynamic response performance. In addition, the proposed control strategy can accurately and stably track the reference value in the transient stage, and this control method is more efficient and simpler.

As a modern concept of cultural practice, “heritage” reflects the ways through which different nation-states understand and construct their own values. Accompanied with the emergency and development of “cultural landscape” concept, the relevance between heritage and landscape has greatly changed how people recognize heritage values, and cultural landscape becomes a specific type of heritage in related research and practice. From the holism perspective of Historic Urban Landscape, practices attempt to interpret the values of heritage by regarding landscape as medium, which helps integrate heritage resources into the overall planning of urban development. From the diversity perspective, the emphasis of the relevance between heritage and landscape promotes the academic system construction on landscape-based heritage research and practice. Heritage landscape research in digital era sees promising potential, meanwhile needs more efforts to address basic technique problems.

As a method of the systematic conservation of historical, cultural, and natural landscape resources, heritage corridor integrates contexts of humanism and nature and provides the public with continuous linear spaces for recreation, leisure, and fitness activities. Most traditional studies on heritage corridor route planning focus on the analysis of physical spatial conditions, while ignoring public perception and public participation mechanisms. Based on the concept of Historic Urban Landscape, this research excavates modern landscape resources that are closely connected with traditional heritages and analyzes users’ digital footprints to incorporate public preferences of recreational behaviors into the process of heritage corridor route planning, realizing the combination of physical and social semantic data analyses. Basically, this study consists of three parts: 1) through analysis of digital footprints, select urban traditional heritage sites and landscape resource spots into the process of heritage corridor route planning, and fit the preliminary routes of urban heritage corridors with minimum cumulative resistance model; 2) construct a co-word matrix consisting of users’ movement flows and online textual data in the digital footprints, to complete the route planning upon social semantic data analysis; and 3) superimpose the results of heritage corridor route planning generated by the above two steps, and optimize according to the reality of urban environment. The study realizes an effective integration of urban landscape resources with public recreational behaviors and spatial perception in the process of heritage corridor route planning, offering reference to the overall protection of urban heritages and the systematic improvement of public space.

Crosstalk between lines plays an important role in the transmission of signal. Hence it is of great significance to establish the transmission lines model accurately to evaluate factors affecting crosstalk coupling between lines and to improve the anti-interference capability of the system. As twisted-pair line is widely used for its unique twist structure which improves the anti-interference performance of cables, this paper presents a method of constructing transmission lines model of the shielded twisted-pair line (STP) with two twisted pairs based on S-parameters. Firstly, the transmission lines model of STP with one twisted pair is established. The establishment of distributed capacitance matrix of this model depends on the dielectric constant of insulation layer that surrounds a conductor, but the dielectric constant is often unknown. In this respect, a method to obtain the distributed capacitance matrix based on the S-parameters of this model is proposed. Due to twisting, there is a great deal of variability between the distribution parameters along the length of the STP. As the spatial distribution of conductors in the cross-section of twisted-pair line vary along with the cable length, the distribution parameters matrices also change as they move. The cable is divided into several segments, and the transmission lines model of STP is obtained with the cascade of each segment model. For the STP with two twisted pairs, the crosstalk between pairs is analyzed based on the mixed mode S-parameters. Combined with the transmission lines model of STP with one twisted pair, that of STP with two twisted pairs is obtained. The terminal response voltage can be calculated from the transmission lines model and cable terminal conditions. The validity of the transmission lines model is verified by the consistency between the terminal responses calculated by the model and by the simulated. As the theoretical and simulation results are compatible, the modeling method for the STP with two twisted pairs can be used for the STP with more twisted pairs. In practical engineering application, S-parameters and mixed mode S-parameters can be obtained by testing. That means the transmission lines model of STP can be established based on the test results.

3D simulation of the near-field radiation emission of large array antenna needs large computing resources and high memory requirements. It is proposed that a method for calculating the near-field radiation emission of an array antenna based on the pattern simulation of a single array element and superposition calculation. For an platform, the radiation emission of large array antenna is often considered, and the concerned position is usually the near-field of the array antenna and the far-field of the array element. The influence of adjacent array elements on the pattern of central array element is analyzed through 3D simulation, and the pattern of a single array element in the array antenna is obtained. Then the near-field radiation emission of the array antenna is calculated from the superposition of the pattern of a single array element. The 3D near-field simulation of the whole array antenna verifies the accuracy of the proposed method. The proposed method requires less computing resources and has fast computing speed.

This paper analyzes the typical functions of digital control circuit and its function modules, and develops a set of digital control circuit equipment based on Advanced RISC Machines (ARM) with typical function modules, including principle design, interference injection trace design, function design, and study the failure mode and threshold of typical function modules. Based on continuous wave (CW) and pulse wave, the direct power injection (DPI) method is used to test the conduction immunity of the digital control circuit, and the failure mode and sensitivity threshold of the digital control circuit are quantitatively obtained. This method can provide experimental verification for the immunity ability of the digital control circuit to different electromagnetic interference.

Purpose The purpose of this paper is to introduce an innovative theoretical, numerical and experimental investigations on the HP NGD function. The identified HP NGD topology under study is constituted by first order passive RC-network. The simulations and measurements confirm in very good agreement the HP NGD behaviors of the tested circuits. NGD responses with optimal values of about -1 ns and cut-off frequencies of about 20 MHz are obtained. Design/methodology/approach The identified HP NGD topology understudy is constituted by a first-order passive Resistor-capacitor RC network. An innovative approach to HP NGD analysis is developed. The analytical investigation from the voltage transfer function showing the meaning of HP properties is established. Findings This paper introduces innovative theoretical, numerical and experimental investigations on the HP NGD function. Originality/value The NGD characterization as a function of the resistance and capacitance parameters is investigated. The feasibility of the HP NGD function is verified with proofs of concept constituted of lumped surface mounted components on printed circuit boards. The simulations and measurements confirm in very good agreement the HP NGD behaviors of the tested circuits. NGD responses with optimal values of about −1 ns and cut-off frequencies of about 20 MHz are obtained.

Shielding effectiveness (SE) evaluation of electrically large enclosures within reverberation chambers (RCs) is standardized procedure for electromagnetic compatibility (EMC) applications. In this work, the potential relationship between SE and electromagnetic resonances has been investigated with respect to the ambiguity in definition of SE for the international standards, e.g., IEC 61000-4-21 or IEEE Std 299.1. From a statistical point of view, we derive the expansions of SE defined by the ratio of the maxima and the averages. To evaluate SE more prudently as well as to obtain a much smaller uncertainty, we can make the tradeoffs for SE, which should be defined as the ratio of the averages for the overmoded frequency and the ratio of the maxima for the undermoded using a common criterion aimed to discriminate the electromagnetic field behavior between the undermoded and the overmoded and also verify the corresponding results by numerical simulations and measurement performed in RC.

For arbitrary electrically large cavities, the ideal reverberant frequency is of critical to predict the response of the reference antenna or the electronics inside. To determine the ideal reverberant frequency, this work has carried out a comparison study on the scattering parameter S11 and S21 based methods for the general case in reverberation chamber (RC). For the two methods, both of them share the same theoretical basis according to the ergodicity principle, i.e., the ideal field distribution and the commonly used correlation analysis. While for arbitrary electrically large cavities, the S11 samples rely on the mechanical stirrer (which is not easy to be equipped like that of a classic RC), S21 samples are more easily recorded by frequency stirring technique. And the corresponding experimental results show that the S21 based method can provide a more conservative estimate of the ideal reverberant frequency.

Crosstalk of multi-conductor transmission lines is a problem often encountered in signal integrity analysis. The calculation of distribution parameters of transmission lines is the premise of solving crosstalk. For this type of non-uniform transmission lines with cylindrical insulating medium, numerical methods are usually used to solve the capacitance matrix, which requires that the dielectric constant of the insulation be known, but it is unknown or it is difficult to know. In this paper, a method of obtaining capacitance matrix by S-parameters is proposed. Taking a three-conductor transmission lines as an example, the capacitance matrix is calculated through the S-parameters obtained by simulation. On this basis, the equation of three-conductor transmission lines is established, and the response voltage of transmission lines port is solved. Compared with the simulated port voltage, the effectiveness of the proposed method is verified.

This paper develops a circuit theory on bandpass negative group delay (NGD) topology. The NGD active lumped circuit uses a low noise amplifier (LNA). An S-parameter model is formulated. Unfamiliar, NGD function analysis is introduced by analytically defining the NGD value, bandwidth, and central frequency as a function of the topology parameters. The synthesis formulas enabling the calculation of cell parameters as a function of the targeted bandpass function specifications. To validate the circuit theory, an NGD proof of concept (PoC) is designed, simulated, and tested. As expected, simulations and measurements are in good agreement. Calculated model, simulated and measured results showing NGD level of about −10 ns around the centre frequency 0.5 GHz over the bandwidth 50 MHz validate are obtained.

Although various measurement techniques have been applied to both qualitative and quantitative evaluation for the electromagnetic shielding performance of braided-shield power cables, the existing measurements cannot directly assess the low-frequency shielding performance (typically below 100 kHz) due to factors such as ground-loop effects and dynamic range problem in measurement. To solve these, an improved shield reduction factor method, based on gain (T/R) rather than scattering parameters, is proposed to evaluate the shielding performance of braided-shield power cables from 25 Hz to 1 MHz. In this work, we highlight the implementation of measurement setup to avoid the effects of ground-loop and stray electromagnetic field. Meanwhile, the test cell is simplified according to the definition of the shield reduction factor in order to obtain the gain (T/R) parameters, which can be used to calculate transfer impedance as well. From the measurements we present more intuitive evaluation of shielding behavior of braided-shield power cables at low frequency regimes, and showcase a detailed comparative discussion between transfer impedance and shield reduction factor. The proposed shield reduction factor method is expected to be a useful way for the evaluation of the low frequency shielding performance of braided-shield cables.

In this interview, three scholars discussed the problems in China’s urban renewal practice in the Internet Era and the context of inventory development. They first reviewed the factors that impact the characteristics and identity of urban space, and pointed out that urban renewals should not neglect the social, cultural, artistic, historical, and ecological qualities of space. They then underscored the aesthetic education will be future research and practice interest in the field of urban renewal. They noted that, under the impact of “attention economy” and ”online influence,” urban spatial construction across Chinese cities would be homogenized, compromising the diversity of spatial characteristics. Nonetheless, urban planners and designers can leverage the online platforms as communication channels and resources for the protection of spatial characteristics and identities, and to foster new urban development paradigms. In addition, the scholars believed that the public should have a greater discourse power in urban renewals, which requires the the promotion of Community Co-building Initiative, and designers’ efforts in promoting related research and education programs. In the end, they discussed the challenges faced by the protection of historical sites, including the outdated urban governance methods, flawed urban development institution, and the lack of funds due to the slowdown of economic growth. They also encouraged designers to respond to these challenges with long-term, proactive, and innovative perspectives, truly meeting citizens’ daily needs, improving urban governance methods, optimizing urban renewal mechanisms, and impelling the growth of local economy.

A comparison study of the maximum field strength within reverberation chamber (RC) is discussed in this work. For this purpose, the maximum scattering transmission coefficients are estimated by generalized extreme value (GEV) and order statistics, respectively, and the corresponding results indicate that order statistics mainly relies on the the number of independent samples which will lead to the overestimates, while the GEV related 95% confidence interval is barely affected in case of the thin tail behavior of the overmoded maximum field statistical distribution. Moreover, the field probe based samples are also given with a comparison of the maximum field strength estimated by GEV theory, the results show that the maximum can be captured with high probability.

This paper first explains the etymological connotation of Glocalization and interprets its authenticity and contemporary significance for studying community building. It argues that understanding Glocalization in specific contexts offers an ideal analysis framework to comprehend the globalization processes of local societies. This paper, by adopting a perspective of micro-globalization, studies the community building in Japan to manifest the influence of the process of Glocalization on Japanese societies. In addition to the political and sociological factors prevalent in the public engagement of community building advocated by western countries, Japanese practice is characterized for emphasizing the cultural significance of the traditional Japanese spatial image. Taking the community building case in Kagurazaka of Tokyo, it illustrates the creative discourse practice in the local community building to probe into the complexity and driving forces in Japan’s Glocalization. In addition, this paper focuses on the role of the localized community in shaping the social relations in Kagurazaka under globalization. By analyzing the contradictions and associations between the bottom-up building and the top-down planning, it discusses the opportunities and challenges faced by the community building in Japan and hopes to offer inspirations for the current community-building movement in China.

This paper develops an innovative design method of a multi-coupled line (CL) topology of low-loss dual band negative group delay (NGD) circuit.The proposed is conceived using three transmission lines (TLs) with different length in which integrate two couplers.The three traveling paths are designed to generate the dual-band NGD effect, where the CLs allow lowering the signal attenuation.The NGD circuit S-parameter model as a function of the TLs physical lengths and coupling coefficient are established.To validate the NGD circuit proof-of-concept, it is fabricated and measured.The NGD values of approximately -4.06 ns and -3.83 ns are measured at center frequencies of 2.43 GHz and 3.02 GHz, respectively.The measured transmission coefficient is better than -2.9 dB and the measured reflection one is better than -12 dB into the NGD band.The measurement results of the NGD circuit are in good agreement with the simulations results.

The modernization of Shanghai has experienced two boosting periods. The first appeared in the 1930s, when it formed the civil society of Shanghai and initially facilitated the trade port into an international metropolis. The second started after the nation’s reform and opening-up, which attempted to promote the city into a global metropolis in the 2010s. In order to evaluate the socio-spatial transitions of communities in Shanghai during the process, Lilong historical neighborhoods in the 1930s and 2010s are successively chosen as research objects. Meanwhile, three specific neighborhoods in each period are selected for case study, so as to depict different symbiosis patterns of the socio-spatial structures under different spatiotemporal conditions by means of a cross-sectional analysis of the consumption level. By pointing out Shanghai in the 1930s was marked with social integration and local-based consumption, while it was inundated with administration tendency and global-oriented consumption in the 2010s, the article believes the dual integration of local-based and global-oriented consumptions is an alternative solution for Shanghai. Finally, the article proposes that Shanghai’s current urban regeneration should rely on the multi-centered symbiotic structure to create a compound network, during which territorial socio-spatial structures and basic living needs of the plebeian can be simultaneously preserved.

To evaluate the performance of oscillating wall stirrer (OWS) in reverberation chamber (RC), the number of independent stirrer positions, and field distributions (in lessmoded, undermoded, and overmoded frequency regimes) are discussed in detail in this work. For the estimation of independent stirrer positions, correlation matrix method (CMM), i.e., threshold-dependent correlation matrix defined by Pearson correlation coefficient, is used to determine the number of independent stirrer positions, where experimental comparative analysis between autocorrelation coefficient in IEC 61000-4-21 and CMM is presented, and the corresponding results provide a reasonable explanation for the overestimation of independent stirrer positions. For the field distributions, parameter M in Bessel K distribution, related to the number of excited modes within Q-bandwidth, is adopted to assess the quasiwall-like behavior of OWS in lessmoded, undermoded, and overmoded RCs, respectively, and the results show that OWS can distribute the field energy that was not sufficiently stirred with a higher probability (>50%) at undermoded frequencies.

One more useful measurement and identification method for common-mode chokes is proposed to analysis frequency-dependent impedance and parasitic parameters information within the balanced frequency range. Equivalent circuit for common-mode chokes is established according to the reciprocal and symmetric physical structure, and S-parameters measured with vector network analyzer have been performed to determine the balanced frequency range. Measurement and identification for frequency-dependent impedance and parasitic parameters has been detailedly discussed, and the corresponding results are obtained through theoretical analysis and calculation. As per the frequency-dependent impedance and parasitic parameters, common-mode and differential-mode signal transmission characteristic within the balanced frequency range can be easlily analyzed, and application performance of common-mode chokes will be improved by optimizing the winding structure or choosing the suitable magnetic material.

Objective To explore the clinical efficacy of the treatment for scaphoid waist fracture assisted by wrist arthroscopy.Methods From January2015 to December 2017,12 cases of fresh scaphoid waist fracture were treated with closed reduction and percutaneous Herbert screw fixation assisted by wrist arthroscopy.The healing of fracture was observed by regular X-ray after operation.Results All the patients were follow-up for 6 to 12 months,with an average of 10 months.All the fractures healed,with an average healing time of 8.4 weeks.The wrist function was evaluated by modified Mayo wrist score.The results were rated as excellent in 8 cases and good in 4 cases.Conclusion Percutaneous internal fixation with Herbert screw assisted by wrist arthroscopy for fresh scaphoid waist fracture can achieve satisfactory clinical results.