广义正交码索引调制系统的性能分析

摘 要：为了提高码索引调制（code index modulation，CIM）系统的传输效率，提出了一种具有更低复杂度的单输入单输出（single input single output，SISO）的广义正交码索引调制（generalized orthogonal code index modulation，GQCIM）系统。CIM 系统使用扩频码和星座符号传输信息，但只能激活两个扩频码索引和一个调制符号。而 GQCIM 系统以一种新颖的方式克服了只激活一个调制符号的限制，同时充分利用了调制符号的正交性，增加扩频码索引以传输更多的额外信息位，提高了系统的传输效率。此外，分析了GQCIM系统的理论性能，推导了误码率性能的上界。通过蒙特卡罗仿真验证了GQCIM系统的性能，对比发现GQCIM系统的理论和仿真性能一致。而且在相同的传输效率下，结果显示GQCIM系统的性能优于同样具有正交性的调制系统，如广义码索引调制（generalized code index modulation，GCIM）系统、CIM系统、码索引调制-正交空间调制（code index modulation aided quadrature spatial modulation，CIM-QSM）系统、码索引调制-正交空间调制（code index modulation aided spatial modulation，CIM-SM）系统、脉冲索引调制（pulse index modulation，PIM）系统。     

Recent progress of green sorbents-based technologies for low concentration CO2 capture

The increased concentration of CO₂ due to continuous breathing and no discharge of human beings in the manned closed space, like spacecraft and submarines, can be a threat to health and safety. Effective removal of low concentration CO₂ from the manned closed space is essential to meet the requirements of long-term space or deep-sea exploration, which is an international frontier and trend. Ionic liquids (ILs), as a widespread and green solvent, already showed its excellent performance on CO₂ capture and absorption, indicating its potential application in low concentration CO₂ capture. In this review, we first summarized the current methods and strategies for direct capture from low concentration CO₂ in both the atmosphere and manned closed spaces. Then, the multi-scale simulation methods of CO₂ capture by ionic liquids are described in detail, including screening ionic liquids by COSMO-RS methods, capture mechanism by density functional theory and molecular dynamics simulation, and absorption process by computational fluid dynamics simulation. Lastly, some typical IL-based green technologies for low concentration CO₂ capture, such as functionalized ILs, co-solvent systems with ILs, and supported materials based on ILs, are introduced, and analyzed the subtle possibility in manned closed spaces. Finally, we look forward to the technology and development of low concentration CO₂ capture, which can meet the needs of human survival in closed space and proposed that supported materials with ionic liquids have great advantages and infinite possibilities in the vital area.     

On the performance of improved quadrature spatial modulation

Quadrature spatial modulation (QSM) utilizes the in‐phase and quadrature spatial dimensions to transmit the real and imaginary parts of a single signal symbol, respectively. The improved QSM (IQSM) transmits two signal symbols per channel use through a combination of two antennas for each of the real and imaginary parts. The main contributions of this study can be summarized as follows. First, we derive an upper bound for the error performance of the IQSM. We then design constellation sets that minimize the error performance of the IQSM for several system configurations. Second, we propose a double QSM (DQSM) that transmits the real and imaginary parts of two signal symbols through any available transmit antennas. Finally, we propose a parallel IQSM (PIQSM) that splits the antenna set into equal subsets and performs IQSM within each subset using the same two signal symbols. Simulation results demonstrate that the proposed constellations significantly outperform conventional constellations. Additionally, DQSM and PIQSM provide a performance similar to that of IQSM while requiring a smaller number of transmit antennas and outperform IQSM with the same number of transmit antennas.     

以人为本,创造宜人的建筑外部空间

建筑外部空间的规划与设计应充分满足使用者的需求。论文运用环境心理学的理论和方法 ,提出了使用者对建筑外部空间的三个需求层次 ,并据此对中国农业大学东校园建筑外部空间进行了使用状况的调研 ,得出一些结论 ,以期为类似建设项目提供一定参考     

单元式住宅户内入口空间的设计

通过对单元式住宅室内入口空间的功能分析 ,列举了入口空间的两种类型 ,分析了入口空间的家俱布置与合理尺寸 ,指明了入口空间对于小康住宅的重要性 ,从而阐述了它的现实意义     

Potential for energy saving in building transition spaces

This paper reports on an analytical investigation into the energy saving potential associated with modified comfort limits in transitional spaces in buildings. Such spaces may not require the same high level and close environmental control of more fully occupied spaces and thus a wider variation in conditions and interpretation of thermal comfort may be permitted. Estimations are made of energy saving potential based upon typical floor area proportions utilised for transition spaces of various types in office/commercial buildings. The data are combined with suggested norms for comfort expectation that have wider temperature limits than for normally occupied office zones. The method has been applied to a series of building types situated in the climate of the East Pennines area of the UK using a thermal analysis tool. The results show that useful energy savings (particularly for heating) are possible by allowing for a modest (and realistic) relaxation of prescribed comfort standards in transition spaces. Further work is now required to confirm the limits and assess energy saving in practice.     

浅谈图底关系理论在城市设计中的应用

图底关系理论是美国康奈尔大学的罗杰·特兰西克教授在《寻找失落的空间》一书中提出的一种有关城市设计的重要理论。本文着重探讨了该理论在城市设计中的应用前景,并通过实例阐述了该理论在城市空间总体层面和城市空间具体层面上的应用价值和方法。     

The relative influence of wind,sunlight and temperature on user comfort in urban outdoor spaces

This paper presents the development of a comfort index that measures adaptivity in outdoor spaces. Over a 9-month period 649 people were surveyed in three locations, in temperatures between 10 and 28 °C. An exploratory factor analysis develops a 15-item scale of comfort that includes measures of adaptivity: clothing, exposure time and seating location. The scale is regressed on physical measures: average instantaneous wind speed; maximum wind speed; mean-exposed radiant temperature; mean-shaded radiant temperature and ambient temperature. The results model the relative contributions of the microclimatic factors for the comfort in the outdoor space. Analyses suggest gustiness and wind speed are most important in determining user satisfaction. There is strong support for the theory that people actively adapt to microclimatic conditions.     

紫薇田园都市国际学校和国家级示范高中

新的教育模式和新的教学理念对校园功能布局、总体规划及单体建筑提出了新的要求。学校创作主题应是创造功能齐全、环境亲切、空间渗透并有时代气息和文化品位的人文学校建筑,紫薇田园都市国际学校和国家级示范高中项目就此作出了尝试。