Computer Aided Simulation on Precision Cold Forging of Universal Joint Cross

IntroductionThefiwtee1emenmethod(FEM)playsanextrmelyimPortantroleintheanalysesofengineeringproblems.ForalongtimethismethodhasmainlybeenaPPliedinthelinearfieldandshownitsgreatpower.HoweveealOtofnonlinearengineeringPrOblemsWhichcanneitherbesimPlyreducedtolinearonesnorrCPresentedbylinearlyanalogywhichshallchnsethePfacticalconditionsrelativelymuch,havechallengedfiniteelementmethod(FEM).RecentymuchProgresshasbeenmadebothinthemathematicalandmechanicaltheoryandthecomPulertechnologysothatevent…     

Variation of households<Emphasis Type="Bold">’</Emphasis> car ownership across time: application of a panel data model

For economic and environmental policy formulation and with the effort of creating less car dependent societies, it is important to study the changing characteristics of car ownership in a household through time as well as factors responsible of these variations. There is a vast body of literature on empirical studies of car ownership and use. These studies have investigated the socio-economic background of the decision maker, the built environment and the perception associated with owning a car as determinant factors of car ownership and use. In most cases, these analyses have been carried out using cross-sectional data sets. However, the analysis of factors determining changes in travel behavior of an individual or household requires information on their behavior over time (longitudinal data set). In this study, the German Mobility Panel (1996–2006) is used to examine variation of car ownership through time and across households. The panel data modeling results showed that there are variations of car ownership between households whereas changes in car ownership of a given household over time (within household variations) are insignificant. The influence of other factors such as the households’ socio-economic background, the availability of public transportation and shopping/leisure facilities, perception on parking difficulties and satisfaction with existing public transportation services on the car owning characteristics of households is also presented and discussed in this paper.

Symbolic dynamics and entropies of copepod behaviour under non-turbulent and turbulent conditions

We consider here behavioural activity of copepods as a succession of symbols associated with swimming states: slow swimming, fast swimming, break and grooming. We characterise these symbolic sequences using tools from symbolic dynamics: probability density function of the residence times in each state; transition probability at each time step; Shannon entropy and dynamic entropy. This approach is applied to the swimming behaviour of Centropages hamatus which we have analyzed as an example of application, in order to stress the differences associated with turbulent and non-turbulent conditions. We characterise in this theoretical framework the behavioural changes exhibited by the copepod under turbulent conditions.     

船舶结构气幕减振的模型试验研究

对船舶结构气幕减振的模型试验研究作了介绍和讨论。试验模型为铝质,平底,尖首,方尾,开口薄壁型船模,试验在循环水槽中进行,通过2种吃水,2种喷气孔径,5种喷气流量,2种水流速度的选择组合,研究了气幕对船模自由振动,强迫振动和振动阻尼的影响,试验结果表明,气幕对船舶结构的强迫振动响应有较大的抑制作用,有明显的降噪效果,气幕减振有重要的应用前景。     

Interpretation of cruise industry in a two-sided market context: An exploration on Japan

Two-sided markets are characterised by the presence of an intermediary and two groups of end-users. In the cruise market, cruise lines may play the role of intermediaries to connect the two end-users, viz. cruise passengers and cruise ports. Our research explored whether the cruise industry can be regarded as a two-sided market, starting with a theoretical modelling. The findings show that cruise lines might be hybrid intermediaries, selling their own ship-based products and services, while offering also a platform to enable the transaction between cruise passengers and cruise ports. This particular business model of a quasi-two-sided market is also reflected in the pricing scheme of cruise industry, whereby cruise ports charge an entry fee from cruise lines and port dues from cruise passengers. We illustrate an empirical analysis on the basis of the cruise market in Japan, and it provides a preliminary clue that the behaviours of cruise ports and cruise lines are consistent with our theoretical framework. The results are not convincingly significant due to data limitations, hence, the concept of a ‘two-sided market’ in the cruise industry call for further empirical research.     

Digging Deep: Managing Social and Policy Dimensions of Geoduck Aquaculture Conflict in Puget Sound,Washington

Shellfish aquaculture can result in conflicts among stakeholders who perceive impacts and tradeoffs regarding sense of place, aesthetic, recreational, economic, and ecological values. Pacific geoduck clams (Panopea generosa Gould 1850) are grown in intertidal plots using gear- and labor-intensive techniques that result in a high value export product. A confluence of issues has resulted in on-going social and legal tensions surrounding geoduck aquaculture in southern Puget Sound, Washington (WA), USA. Using interviews and document analysis, we explored stakeholder perspectives and policy issues related to geoduck aquaculture in southern Puget Sound. Twenty-three stakeholders were interviewed, including state agency employees, representatives of the aquaculture industry, nongovernmental organizations, landowners, a tribal member, and an academic. Nine state hearings board decisions on challenges to aquaculture permits were also analyzed. Stakeholders articulated a variety of perspectives regarding aesthetic, recreational, land-use, ecological, political, regulatory, and economic aspects of geoduck aquaculture activities. Hearings board cases addressed similar issues (aesthetic, ecological, and recreational), as well as challenges to restrictions on aquaculture. Potential strategies for managing this conflict include emphasizing best management practices, identifying and incorporating best available science, joint fact-finding approaches, and initiating and improving communication among all stakeholders.     

Improving maritime English competence as the cornerstone of safety at sea: a focus on teaching practices to improve maritime communication

The International Maritime Industry (IMI) is a global web of shipping, connecting all Continents and bringing together mariners from a multitude of national, ethnic and linguistic backgrounds. Wherever humans interact, they communicate in some form or another and the ability to communicate competently is the cornerstone of safety at sea. This paper identifies the growth of English as the lingua franca of the sea, as a framework for the later discussion on current teaching practices. We consider that Maritime English (ME) fits into the category of a special-purpose form of English, in that it has generated, modified or adopted from other languages many terms and phrases that are only used in the IMI. This paper considers safety-to-practice as a factor in curriculum design, teaching and assessment as the basis for ME competence. Further, we propose opportunities to move industry focus forward, through collaboration with stakeholders and discussion about teaching practices. This paper identifies a gap in maritime teaching practices. This paper further explores the use of authentic teaching as a way forward to improve maritime communication.     

Gender inequality in mobility and mode choice in Pakistan

Using the nationally representative dataset of the 2007 Pakistan Time-Use Survey, this paper examines gender differences in daily trip rate, mode choice, travel duration, and purpose of travel, which are previously unreported because of limited data availability. Wide gender mobility gaps are observed in the country, where women are less likely to travel, are half as mobile as men and may rely heavily on walking. The particular social and cultural context of the country, that renders women as private, secluded and family honor, seems influential in shaping their mobility and choice of activities. Demographic factors such as age, household income, and marital status significantly decrease female mobility levels. Hence, these findings call for a gender-based culturally responsive transportation policy in the country.     

Efficiency measurement in public transport: Are findings specification sensitive?

The need to measure transit system performance along with its various dimensions such as efficiency and effectiveness has led to the development of a wide array of approaches and vast literature. However, depending upon the specific approach used to examine performance, different conclusions are oftentimes reached. Using data from 15 European transit systems for a ten year time period (1990-2000), this paper discusses three important transit performance questions; (i) Do different efficiency assessment methodologies produce similar results? (ii) How are the two basic dimensions of transit performance, namely efficiency and effectiveness, related? and (iii) Are findings regarding organizational regimes (public operations, contracting and so on) sensitive to the methodological specifications employed? Results clearly indicate that efficiency scores and associated recommendations are sensitive to the models used, while efficiency and effectiveness are - albeit weakly - negatively related; these two findings can have far reaching policy implications.