Property of critical excitation for moment-resisting frames subjected to horizontal and vertical simultaneous ground motions

It has often been reported that, when building structures are subjected to near-fault earthquake ground motions, horizontal and vertical impulsive inputs may cause critical damage during the first few seconds. In practical design of building structures, however, the safety check, taking into account the effect of multi-component ground motions, is hardly conducted except the design of important structures such as high-rise buildings and nuclear power plants. Ftirthel＇more, it is not clear how the correlation of multi-component ground motions influences the actual safety of structures. In this paper, the detailed property of critical excitation is discussed in association with the relationship between the characteristics of ground motions and those of structures. The properties of various auto power spectral density （PSD） functions of the horizontal and vertical ground motions are investigated, and those of the critical cross PSD function of these two-directional ground motions are found by a devised algorithm in a feasible complex plane. A closed-form expression is derived from the critical relation of the auto PSD functions of the simultaneous inputs. This critical excitation method provides us with a new approach for earthquake-resistant design against the possible future earthquake which causes the critical damages to buildings.     

用于钢筋混凝土受弯构件补强加固的碳纤维织物的力学性能

讨论了用以测定碳纤维织物的抗拉强度及弹性模量等有关力学性能指标的相关方法 .对 5根碳纤维织物补强加固简支梁进行了试验研究和计算机模拟分析 ,试验数据与分析数据符合较好 ,说明碳纤维织物的实测力学性能指标可靠合理 .同时 ,在对试验数据进行分析整理的基础上 ,得出了碳纤维织物补强加固钢筋混凝土受弯构件正截面承载力的简化设计公式 .     

Determinants of R&D cooperation in Japanese start-ups

This paper explores the determinants of R&D cooperation in Japanese start-ups. Using a sample from an original survey conducted in 2008, we examine the effects of founder-, firm-, and industry-specific characteristics on R&D cooperation by type of partners. Our findings indicate that founder-specific characteristics such as educational background, prior innovation output, and affiliation to academic associations are fairly important in determining R&D cooperation with academic institutes (universities and public research institutes). We also provide evidence that founders’ prior innovation output and work experience have positive and significant effects on R&D cooperation with business partners. With respect to firm-specific characteristics, it is found that firms investing more in R&D tend to engage in R&D cooperation, regardless of the type of partners. Furthermore, it is found that independent firms are less likely to cooperate in R&D with academic institutes than subsidiaries and affiliated firms.     

Early Conversations and Word Learning: Contributions from Child and Adult

Temporal and topic contingencies between child and mother speech are reported at 2 achievements in language development in the second year. Measured against their respective baseline rates of speech, children were most likely to talk before mother speech and mothers most likely to talk after child speech. This pattern, evident at both language achievements, increased in amplitude with development. These early conversations were generated by the children; neither their interactions nor word learning depended on adult-scaffolded formats. Only about one-third of all child speech occurred in response to something mothers said; only half of all child speech received a topic-related response. When mothers responded, they most often simply acknowledged, repeated, or clarified what the child said. The results supported the intentionality model for language development, in which the child's role is primary: Children learn words for expression and interpretation in order to share contents of mind, bringing words to their conversations that they've already learned in other contexts.     

Electromyographic analysis of hip adductor muscles in soccer instep and side-foot kicking

ABSTRACT

A possible link between soccer-specific injuries, such as groin pain and the action of hip adductor muscles has been suggested. This study aimed to investigate neuromuscular activation of the adductor magnus (AM) and longus (AL) muscles during instep and side-foot soccer kicks. Eight university soccer players performed the two types of kick at 50%, 75% and 100% of the maximal ball speed. Surface electromyography (EMG) was recorded from the AM, AL, vastus lateralis (VL) and biceps femoris (BF) muscles of both kicking and supporting legs and the kicking motions were three-dimensionally captured. In the kicking leg, an increase in surface EMG with an increase in ball speed during instep kicking was noted in the AM muscle (p < 0.016), but not in AL, VL or BF muscles (p > 0.016). In the supporting leg, surface EMG of both AM and AL muscles was significantly increased with an increase in the ball speed before ball impact during both instep and side-foot kicks (p < 0.016). These results suggest that hip adductor muscles markedly contribute to either the kicking or supporting leg to emphasise the action of soccer kicks.     

The effects of a 4-week static stretching programme on the individual muscles comprising the hamstrings

The aims of this study were to investigate the effects of a 4-week intervention of static stretching (SS) on muscle hardness of the semitendinosus (ST), semimembranosus (SM) and biceps femoris (BF) muscles. Shear elastic modulus was measured by using ultrasound shear wave elastography as the index of muscle hardness. Thirty healthy men (age 22.7 ± 2.2 years) volunteered for this study and were randomly assigned to the SS intervention group (n = 15) or the control group (n = 15). Participants in the SS intervention group received a 4-week stretch intervention for the hamstrings of their dominant leg. Shear elastic moduli of the hamstrings were measured at initial evaluation and after 4 weeks in both groups at a determined angle. In all muscles, the shear elastic modulus decreased significantly after SS intervention. The percentage change in the shear elastic modulus from the value at initial evaluation to after 4 weeks intervention was greatest in the SM. These results suggest that SS intervention has chronic effects on reducing hardness of the hamstring muscle components, especially the SM muscle.     

What Children Have Lost by the Modernisation of Education: A Comparison of Experiences in Western Europe and Eastern Asia

The discovery of the proper value of childhood during the 18th century in Europe was an important break-through. People began to respect childhood as a sacred world that should not be judged from the standpoint of adults. However, in today' world many children are subjected to all kinds of physical and mental pain, including the so-called examination hell in some Asian countries. Children now live in a paradoxical situation. Theoretically they have obtained the right to enjoy their own world, approved and protected by adults, but in practice they cannot adapt themselves smoothly to the world mainly ruled by the logic of grown-ups. This paper argues that it is time to re-evaluate what has been lost under the slogan of modernisation. The solution is not simply to return to the pre-modern situation but rather to consider what elements from the past could be re-activated to the benefit of children today.     

Novel noun and verb learning in Chinese-, English-, and Japanese-speaking children

When can children speaking Japanese, English, or Chinese map and extend novel nouns and verbs? Across 6 studies, 3‐ and 5‐year‐old children in all 3 languages map and extend novel nouns more readily than novel verbs. This finding prevails even in languages like Chinese and Japanese that are assumed to be verb‐friendly languages (e.g., T. Tardif, 1996 ). The results also suggest that the input language uniquely shapes verb learning such that English‐speaking children require grammatical support to learn verbs, whereas Chinese children require pragmatic as well as grammatical support. This research bears on how universally shared cognitive factors and language‐specific linguistic factors interact in lexical development.