变频空调器及其节能

变频空调器是一种新型机种.变频技术在空调器中的应用,使得空调在整机性能、舒适性等方面得以大大提高.     

高技能人才短缺：一个专用性人力资本的分析框架

高技能人才的人力资本特性更多表现为专用性人力资本。我国高技能人才短缺的主要原因是高技能人才的市场价值存在＂偏离＂,从而使投资风险加大;在高技能人才培养上的错位和一些体制性障碍也加剧了高技能人才的短缺。根据高技能人才的人力资本特征建立合理的技能人才人力资本评价体系,并合理配置政府、各类教育机构、企业和个人的资源,形成高技能人才人力资本投资的多元分担模式,进而构建高技能人才人力资本投资风险防范体系是缓解我国高技能人才短缺的可行途径。     

从换路定律证明看扩充实数的必要性

指出了在电路分析课程中换路定律证明方面存在的矛盾,证明矛盾的根源在于实数的完备性,并依此说明了建立广义实数概念的必要性.     

高中生化学探究学习能力及其培养

培养学生的探究学习能力是高中化学教学的重要课题.教师在教学过程中根据教学内容和学生实际优化实验,创设教学情境,进行开放性教学,鼓励合作探究并重构评价方式,从而不断提高学生的探究学习能力.     

追寻优质的数学教育——一所综合了东西方教育理念的美国高中学校简介

美国的一些重点学校非常重视资优生的培养,并确实做到了因材施教.由于中美中小学教师从不同的视角进行教学,中美数学教育的研究方向和焦点及教师的教学方法有很多不同的地方.中国的教育应该思索和继承中华民族好的教学传统,同时学习和吸收发达国家培养优秀人才的经验,以保证和提升基础教育在世界的领先地位,同时,要在中学阶段因材施教,充分重视数学资优生的培养.不能以美国有多少诺贝尔奖获得者来抨击中国的中小学教育.     

高温条件下劳动者权益的保护问题研究——基于对《防暑降温措施暂行办法》的分析

随着全球气候变暖,高温极端天气在世界频现,劳动者在高温条件下工作,严重危及的身体健康和生命安全,而我国现行的法律对于高温条件下劳动者权益的保护比较模糊,缺乏可操作性。对我国高温条件下劳动者权益保护的现状以及存在的问题进行分析,提出应完善我国高温条件下劳动者权益保护的具体措施,以适应社会发展的需要。     

句子音高级别定位和音高层标注——《英语语调模式及声学实现》中“音高水平”引发的思考

《英语语调模式及声学实现》一文中“pitch level”被翻译成“音高水平”,这种表达法在学习者语调分析中容易产生歧义;另外,体现“音高水平”具体内涵的“高域”、“中域”和“低域”等概念界限模糊,且在学习者口语音高标注及分析中可操作性不高。笔者首先针对这些问题进行分析;然后从句子音高级别定位人手,以实例说明音高层标注...     

Extraction of novel features for emotion recognition

Hilbert-Huang transform method has been widely utilized from its inception because of the superiority in varieties of areas. The Hilbert spectrum thus obtained is able to reflect the distribution of the signal energy in a number of scales accurately. In this paper, a novel feature called ECC is proposed via feature extraction of the Hilbert energy spectrum which describes the distribution of the instantaneous energy. The experimental results conspicuously demonstrate that ECC outperforms the traditional short-term average energy. Combination of the ECC with mel frequency cepstral coefficients (MFCC) delineates the distribution of energy in the time domain and frequency domain, and the features of this group achieve a better recognition effect compared with the feature combination of the short-term average energy, pitch and MFCC. Afterwards, further improvements of ECC are developed. TECC is gained by combining ECC with the teager energy operator, and EFCC is obtained by introducing the instantaneous frequency to the energy. In the experiments, seven status of emotion are selected to be recognized and the highest recognition rate 83.57% is achieved within the classification accuracy of boredom reaching 100%. The numerical results indicate that the proposed features ECC, TECC and EFCC can improve the performance of speech emotion recognition substantially.     

4-component 2-D CFDFD method in analysis of lossy circular waveguide with fractal rough surface

In this paper, equivalent surface impedance boundary condition (ESIBC), which takes fractal parameters (D, G) into SIBC, is implemented in the 4-component 2-D compact finite difference frequency domain (2-D CFDFD) method to an- alyze the propagation characteristics of lossy circular waveguide with fractal rough surface based on Weierstrass-Mandelbrot (W-M) function. Fractal parameters’ effects on attenuation constant are presented in the 3 mm lossy circular waveguide, and the attenuation constants of the fi...     

Optical QPSK/16QAM modulation based on serial-parallel MZM scheme in radio-over-fiber system

A novel scheme of optical modulation in 40 GHz radio-over fiber (RoF) system is proposed. It generates optical QPSK/16QAM signals in a serial-parallel structure of Mach-Zehnder modulators (MZMs). The millimeter-wave is obtained with optical frequency multiplication (OFM). Furthermore, modulation on optical-wave is transferred onto millimeter-wave. It can be used to increase transmission capacity of millimeter-wave RoF systems.