Information Systems-based Real Estate Macrocontrol Systems

With the continuous increase of marketization and normalization in the Chinese real estate market, the market mechanism now plays an important role in market regulation. The existing macro-control system for the real estate market, however, appears to lack the ability to regulate it. Thus, an effective and efficient information-oriented tool is needed to guide the development of China’s real estate market. The research reported herein constructs a new macro-control system for this market that is based on information systems, specifically, a real estate warning system, a confidence index system, and a simulation system. This paper first presents the framework of the new information systems-based macro-control system, and its functions are analyzed. The methods of constructing the system are then discussed. Based on these methods, the index systems of the respective information systems are established, and the main models are presented. Finally, a case study that is based on survey data from the Shenzhen real estate market is described to demonstrate the applicability of the new macrocontrol system.Real estate; Macro-control system; Warning system; Confidence index; System simulation

Exhumation History of the Greater Khingan Mountains (NE China) Since the Late Mesozoic: Implications for the Tectonic Regime Change of Northeast Asia

The Greater Khingan Mountains (GKMs) are a prominent orogenic zone in Northeast Asia that offers significant insights into the evolution of the Mongol-Okhotsk Ocean and the Pacific Ocean during the Phanerozoic. A comprehensive study integrating a low-temperature thermochronology analysis pertaining to the Greater Khingan area and its associated basins has been conducted. Apatite fission-track (AFT) tests conducted on detrital samples from the GKMs in Northeast China have yielded central ages ranging from 260 to 62 Ma. Two-dimensional thermal history inversion modeling and three-dimensional numerical simulations were used to investigate the GKMs' thermal history, revealing at least two distinct tectonic cooling and exhumation events: one occurring between 147 and 70 Ma and another around 35 Ma. The fission-track age groups of the GKMs, Hailar-Erlian Basin, and Mohe Basin bear some resemblance (>105 Ma), but the results from the Songliao Basin are unique. This implies that the Songliao Basin and the GKMs were likely under the influence of different tectonic domains during this period, while AFT age peaks between 105 and 45 Ma, indicating the basin-mountain systems were likely influenced by a unified Paleo-Pacific plate process, which prevailed from about 105 Ma. The 147–70 Ma cooling event can be attributed to the combined effects of the compression orogeny, resulting from the closure of the Mongol-Okhotsk Ocean during the Early Cretaceous and the extension orogeny triggered by the subduction of the Paleo-Pacific Ocean during the early Late Cretaceous. Since approximately 35 Ma, the increase in Pacific plate subduction speed may have established a post-arc extensional tectonic environment in the GKMs that has persisted until now

Optimal operation strategy for subway HVAC system in transition seasons

This paper mainly studied the operation strategy for subway VAC system during transition seasons. Two modes including WF-AC (Whole Fresh air- Air Conditioning) mode and B/E-V (Back/Exhausted fan-Ventilation) mode were selected based on energy saving principle. In order to decide the optimal operation mode, the calculation method of “switching temperature” was proposed. The main influencing factors of the switching condition include indoor cooling load, COP of the chilled-water-system, temperature difference of the supply air, efficiency of fan and the resistance of air duct. Also, the transfer temperature diagram is provided based on proposed calculation method, which is suitable for engineering use. The aim of this study is to regulate the operation mode and to promote energy saving in subway station

Deep Metric Learning with Self-Supervised Ranking

Deep metric learning aims to learn a deep embedding space, where similar objects are pushed towards together and different objects are repelled against. Existing approaches typically use inter-class characteristics, e.g. class-level information or instance-level similarity, to obtain semantic relevance of data points and get a large margin between different classes in the embedding space. However, the intra-class characteristics, e.g. local manifold structure or relative relationship within the same class, are usually overlooked in the learning process. Hence the data structure cannot be fully exploited and the output embeddings have limitation in retrieval. More importantly, retrieval results lack in a good ranking. This paper presents a novel self-supervised ranking auxiliary framework, which captures intra-class characteristics as well as inter-class characteristics for better metric learning. Our method defines specific transform functions to simulates the local structure change of intra-class in the initial image domain, and formulates a self-supervised learning procedure to fully exploit this property and preserve it in the embedding space. Extensive experiments on three standard benchmarks show that our method significantly improves and outperforms the state-of-the-art methods on the performances of both retrieval and ranking by 2%-4%

Electromechanical Transient Modeling of Line Commutated Converter-Modular Multilevel Converter-Based Hybrid Multi-Terminal High Voltage Direct Current Transmission Systems

A method for electromechanical modeling of line commutated converter (LCC)-modular multilevel converter (MMC)-based hybrid multi-terminal High Voltage Direct Current Transmission (HVDC) systems for large-scale power system transient stability study is proposed. Firstly, the general idea of modeling the LCC-MMC hybrid multi-terminal HVDC system is presented, then the AC-side and DC-side models of the LCC/MMC are established. Different from the conventional first-order DC-side model of the MMC, an improved second-order DC-side model of the MMC is established. Besides considering the firing angle limit of the LCC, a sequential power flow algorithm is proposed for the initialization of LCC-MMC hybrid multi-terminal HVDC system. Lastly, simulations of small scale and large scale power systems embedded with a three-terminal LCC-MMC hybrid HVDC system are performed on the electromechanical simulation platform PSS/E. It is demonstrated that if the firing angle limit is not considered, the accuracy of the power flow solutions will be greatly affected. Steady state calculation and dynamic simulation show that the developed LCC-MMC hybrid MTDC model is accurate enough for electromechanical transient stability studies of large-scale AC/DC system

Structure, Mechanical and Thermal Properties of TiSiWN Coatings

Elemental alloying has been proven to be a valid approach for improving the performance of coatings and has attracted significant research attention. This study aims to explore the impact of W-addition on the structure, mechanical and thermal properties of arc evaporated TiSiN coatings. Ti0.88Si0.12N coating presents a single-phase structure of fcc-(Ti, Si)N, while Ti0.88Si0.08W0.04N and Ti0.84Si0.09W0.07N coatings show a fcc-(Ti, Si, W)N and bcc-W dual-phase structure. As the W content increases, the surface quality of our coatings is obviously improved on account of the pronounced reduction in growth defects, including macroparticles and holes. Introduction of W slightly increases the hardness from 40.0 ± 0.5 GPa for Ti0.88Si0.12N to 41.6 ± 1.1 GPa for Ti0.88Si0.08W0.04N and 42.0 ± 1.0 GPa for Ti0.84Si0.09W0.07N. All our coatings possess a high thermal stability with their hardness values remaining above 38 GPa even after annealing at 1100 °C. Meanwhile, as a result of the suppressed anatase to rutile TiO2 transformation, alloying with W ameliorates the oxidation resistance of TiSiN coatings. After 750 °C oxidation for 10 h, the W-containing coatings only reveal oxide layers of ~301.5 (Ti0.88Si0.08W0.04N) and 279.2 nm (Ti0.84Si0.09W0.07N), whereas Ti0.88Si0.12N coating has already been entirely oxidized

A network data-based survey and analysis of attention towards breast reconstruction after breast cancer surgery in Chinese and American populations

Background: Breast reconstruction is an effective technique to rebuild the appearance of the breasts in patients after mastectomy and improves the prognosis. The current study aimed to compare and analyze willingness for breast reconstruction after breast cancer between populations in China and the United States, from the perspective of social concern, using big data analysis. We also aimed to explore factors affecting surgical selection and to identify methods that can improve social cognition and acceptance of breast reconstruction. Methods: Using Baidu and Google, two representative Internet search engines in China and the United States as research tools, and using big data search volume as the benchmark, we compared and analyzed breast reconstruction willingness and attention characteristics between Chinese and American people, based on search heat, geographical distribution, age and sex, keyword distribution, ethnic group, and social development degree. Results: In both the long-term and short-term, Chinese people paid more attention towards searching about breast cancer, but less attention to breast reconstruction after breast cancer surgery. However, in both the short-term and long-term, people from the United States paid more attention towards breast cancer and breast reconstruction with the help of the Internet, showing a synchronous change relationship. There was a large regional difference in the search volume for breast cancer among the Chinese population, while no significant regional differences were noted in the search volume for breast cancer in the United States. However, a large regional difference was observed in the search volume for breast reconstruction between the two countries; people in the coastal and economically developed areas paid more attention to it. Most people who paid attention to breast reconstruction in China were women aged 20–39 years, while the attention among men was low. Search keywords were also limited to breast cancer-related information. However, between Asians and European Americans, Americans paid more attention to breast cancer and were affected by regional development, religious beliefs, and health facilities. Conclusion: Attention towards breast reconstruction after breast cancer was lower in the Chinese population than in the American population, and this difference was closely related to the level of regional development. There is insufficient information on breast reconstruction after breast cancer in recent Internet media. In addition to strengthening communication in clinics, media education is important to improve the cognitive level and social awareness of patients and their families, which is conducive to breast reconstruction

Research on transient synchronous stability of integrated grid-forming converters using power synchronization control

The proportion of the integrated converters using PSC （power synchronization control） in power systems is increasing year by year， but there is a lack of in-depth research on the transient synchronization stability. Therefore， the transient synchronization stability mechanism of integrated grid-forming converters using PSC is analyzed， and measures to improve the transient stability of the converter are proposed. First， the transient stability model of the grid-forming converters with PSC during grid fault is established. Subsequently， based on the phase diagram curve （PDC） method， the destabilization mechanism of the converters and the effect of voltage coupling on the transient synchronous stability are investigated. Moreover， a control strategy to improve the transient synchronous stability by dynamically adjusting the active power command value is proposed based on the effect of voltage coupling. Finally， the electromagnetic transient simulation model of an equivalent system in a city is constructed by using PSCAD/EMTDC， which verifies the correctness of the transient stabilization mechanism of the converter-connected power system and the effectiveness of the stabilization enhancement measures under different fault conditions