Research and evaluation of the measurement uncertainty with the two-dimensional optical calibration plate

As a portable standard, two-dimensional optical calibration plate is playing an increasingly important role in precision industry measurement. Therefore, it is of great scientific significance and obvious socioeconomic benefits to carry out the research of comparator. This paper was based on rich experience with the institute in the field of the geometric measurement technology for a long time, the measurement uncertainty of the optical calibration plate was studied, and the measurement uncertainty of the instrument has been researched. The measurement uncertainty of the error of the calibration plate’s setting and marking value was U= (0.14+ 0.015L) m k=2 L: mm.

Impact of clusters on regional economic performance

Purpose – This paper aims to examine the methodology used to identify clusters on the one hand and assess the economic impact that those may have on regions on the other hand. Design/methodology/approach – The influential work on “clusters”lead by Michael Porter since the 1990s has become a tool for promoting innovation and growth at national and regional level. Even if the theory has become very popular, a few empirical investigations were conducted since. In a recent study, Delgado, Porter and Stern developed a model to investigate the impact of cluster composition on the performance of regions in the USA. They find strong evidence that industries operating in a strong cluster environment perform better. The aim of this study is to improve the methodology used in evaluating the cluster environment and then to replicate their model and apply it to a highly competitive industry in Switzerland, namely, the precision goods sector. It enables to look closely at the importance of the microeconomic environment surrounding an industry at the regional level. Findings – In Switzerland, the precision industry forms a traded cluster in three different regions. The model then reveals that those regions perform better. The results show that industries located in or nearby regions with a strong cluster environment experience higher employment growth rates. Originality/value – It highlights the importance of the microeconomic environment even in small competitive countries.

Analysis of Hydrodynamic Porous Bearing with External Pressure Supply

For the need of high speed and load capacity of precision industry, a bearing used in a high speed spindle is studied. The hydrodynamic bearing composed a hydrodynamic bearing made of porous material and several hydrostatic chambers with an external oil system. The hydrodynamic bearing is pressurized with oil chamber and supports the spindle shaft both at rest and at rotation state. Because of the external pressure and the property of porous material, the load capacity of hydraulic bearing can be promoted without decreasing precision. To consider the relationship of parameters, we applied the Reynolds equation and Darcy’s law to describe the flow of the oil film between bearing and spindle shaft.

Customisation and Desirable Characteristics of a Standard Method of Measurement for Building Works in Ghana

This paper reports a study that identified andcategorised the modifications to the 5thEdition of the British Standard Method ofMeasurement (SMM5) of building works inGhana. Typical modifications involved ‘costinsignificant items’, ‘minor labour items’,‘custom units of measurement’, ‘methodrelated items’, ‘combinable items’,‘subordinate items’, and ‘items of minorinformative impact’. It was also observed thatthe desirable characteristics/ qualities ofstandard methods of measurement (SMM) ofbuilding work were noteworthy, since theyprovide insight into the nature of a SMMrequired for the construction industry inGhana.The research reviewed available literature,various SMMs and bills of quantities (BQs).The relevance of the modifications andSMM characteristics identified wasconfirmed by a survey of the opinions ofprofessional quantity surveyors conductedthrough a carefully designed questionnaire.Inferences from the opinion survey formedthe basis for grouping both SMMmodifications found and the desired qualitiesof a SMM for Ghana.Survey respondents confirmed all theidentified modifications to the British SMM,except for the elimination of items of minorinformative impact. It was held that allinformation was relevant in measurement.Desirable characteristics of a SMM were ratedin decreasing order of relevance as: easylocation of items; cost significance; simplicity;thoroughness; ease of cost analysis; goodpractice; conciseness; adoptability; precision;industry practice; stakeholders’ opinion;custom classification; regional relevance; andinclusion of jargon. It was noted that therelevance of these characteristics may varyform one region to the other as a result oftechnological, cultural and legal differences.However, the desired SMM characteristicswere recommended as fundamental indeveloping an appropriate SMM for Ghana.

Special Issue on Japanese-French Congress of Mechatronics

The lst Japanese-French Congress of Mechatronics was held at Besancon City in France from October 20 to 23, 1992. The congress was cosponsored by the Japan Society for Precision Engineering and 1'Institut des Microtechniques de Frenche-Comte. A total of 216 persons participated in the congress, 72 from Japan and 144 from France and other European countries. The total number of announced papers was 84, 49 from Japan and 35 from Europe. In addition, three special addresses were made each from Japan and Europe. The number of robotic addresses totalled 30, the largest number by field. Among these 30 addresses, 23 were made by Japanese participants. Studies in a wide range of mechatronics were also announced which were related to sensors and measurement system and machine vision. Besancon is the capital of Doubs and is an ancient city with a history of 2000 years. Doubs is bordered by Switzerland and has been active in the precision industry, such as watches, since old times. It is mostly industrialized and has been interested in mechatronics. Unique studies have been conducted by some research and educational institutes including Ecole Nationale Superieure de Mechanique et des Microtechniques. The congress received attention as being unique and attracted many participants for the following reasons: there was very little interaction between Japan and France in the field of precision engineering or mechatronics and the French industry, a specific existence in Europe, has recently taken a great interest in Japanese technology. The editorial committee of this periodical urged authors to contribute papers suitable for the periodical among those announced at the congress and contained their contributions in it. Technological interactions between Japan and Europe will become more important. In 1994, the 2nd Japanese-French Congress of Mechatronics (International) will be held at Takamatsu City in Japan. I hope that many researchers and engineers of mechatronics worldwide will join the congress and have discussions on mechatronics to stimulate its growth.