Cross-Border Migration of Hong Kong Residents Under the 'One Country, Two Systems' Policy

Hong Kong is known as a migrant city because its population was sourced from mainland China, and because there has always been outflows of people to overseas countries, especially from the mid-1980s to mid-1990s. Emigration to mainland China has become a significant recent trend. This article discusses this phenomenon in the theoretical contexts of migration and trans-border residential development. It contends that the trend will intensify more quickly than other cross-border movements because the two systems are separated by a political border within one country, and because there are common cultural ties and rapid economic integration.     

Improving traversability of quadruped walking robots using body movement in 3D rough terrains

This paper presents a study on improving the traversability of a quadruped walking robot in 3D rough terrains. The key idea is to exploit body movement of the robot. The position and orientation of the robot are systematically adjusted and the possibility of finding a valid foothold for the next swing is maximized, which makes the robot have more chances to overcome the rough terrains. In addition, a foothold search algorithm that provides the valid foothold while maintaining a high traversability of the robot, is investigated and a gait selection algorithm is developed to help the robot avoid deadlock situations. To explain the algorithms, new concepts such as reachable area, stable area, potential search direction, and complementary kinematic margin are introduced, and the effectiveness of the algorithms is validated via simulations and experiments.     

自然主义——新艺术者的梦幻出口——浅析自然主义在设计史上盛极而衰的原因

自然主义对许多艺术门类都产生过深刻影响,在设计领域中,以自然主义为主要特点的新艺术运动曾在一个重大的设计变革时期——工业革命后风靡各国,然而却又在短短十多年后沉寂下来,本文主要分析自然主义为什么会在设计史的重要阶段产生如此特别的表现。     

Current techniques for measuring motion

The sports scientist and the ergonomist, although sharing a common disciplinary background, pursue fundamentally different goals. The patterns of approach to the analysis of movement they adopt are, nevertheless, similar and a model of this approach is presented. Some potential sources of error associated with each stage of the process are identified.

In measuring motion in sport, cinematography has played a dominant role. The method has obvious advantages; but analysing film is a slow, pedestrian task, and subject to human error. Where an investigator is experienced and understands his problem clearly he can often achieve his aims with a limited number of measurement variables. This may also meanhe can adopt automatic and specific techniques of acquiring information. Such methods include alternative photographic techniques, but also involve the specialised transducers and automatic analysers that are now burgeoning in the field. Some of these techniques are discussed.     

Development and validation of a biodynamic model for predicting multi-finger movements in cylinder-grasping tasks †

This article describes the development and validation of a model for predicting multi-finger movements in grasping activities. The model builds upon a newly proposed approach that incorporates forward dynamics and a system identification procedure, and is amenable to empirical tests. A database of multi-fingered grasping movements performed by 28 subjects was established and divided into four sets, one for model development and three for model validation. In the development phase, model parameter values were estimated by the iterative system identification procedure through a physics-based heuristic algorithm. The estimated parameter values were then statistically synthesised and integrated into the prediction model. In the validation phase, the model was applied to three novel datasets containing different grasping movements involving objects of varied sizes and different subjects. The results demonstrated the model's ability to predict hand prehensile movements with error magnitudes comparable to the inter-person variability in performing such movements. New insights into the control of multi-fingered hand prehensile movements at the systems and joint levels emerged from the model development and validation process. The current study contributes to building a foundation for long-term development of realistic biodynamic simulation of multi-finger hand movements. Such simulation capabilities will aid in design of hand-operated tools, devices or hand-intensive work for proactive ergonomics and in evaluation as well as treatment of functional impairment of the hand.     

20世纪60年代美国青年对抗文化初探

青年对抗文化是20世纪60年代美国社会的一大特色。繁荣的经济，如火如荼的黑人民权运动，“越战”和“新左”思想是对抗文化产生的重要因素。消极的嬉皮士文化和积极的青年学生运动是60年代对抗文化的主要形式。相同的目标，使这两股力量在必要的时候联合起来。他们的努力取得一定成果，成为牵制美国对越战争的主要力量，但是随着60年代末，70年代初美国经济的衰退和右倾势力的强大，学生运动和嬉皮士文化都走向衰落。     

蒸发冷却水质问题的分析研究

蒸发冷却空调是以水作为制冷剂,通过在西北地区的实际工程应用,发现存在着蒸发冷却器表面结水垢以及细菌滋生等水质问题.本文针对这两大问题,从产生的原因、条件以及环境等方面进行了分析;阐述了导致上述两大问题的关键原因,提出从补水、流失水比例、水系统的软化以及抗菌剂的填加等几个环节加强水质管理的措施;通过全面的分析和研究,认为蒸发冷却器不会产生军团病.     

Bed Load Transport Rate in Scouring and Armoring Process of Non-uniform Sediment River Bed

Flume experiments were carried out to study bed load transport rate during rive bed scouring and ar- moring.A theoretical differential equation linking the transport rate to the probability of incipient motion of non-uniform sediment is solved.The transport rate is shown to decrease exponentially with time,according to the theory,which is in good agreement with the experiment data.     

The influence of temperature, pressure, salinity and capillary force on the formation of methane hydrate

We present here a thermodynamic model for predicting multi-phase equilibrium of methane hydrate liquid and vapor phases under conditions of different temperature, pressure, salinity and pore sizes. The model is based on the 1959 van der Waals-Platteeuw model, angle-dependent ab initio inter- molecular potentials, the DMW-92 equation of state and Pitzer theory. Comparison with all available experimental data shows that this model can accurately predict the effects of temperature, pressure, salinity and capillary radius on the formation and dissociation of methane hydrate. Online calculations of the p-T conditions for the formation of methane hydrate at given salinities and pore sizes of sediments are available on: www.geochem-model.org/models.htm.