TWO SCHEDULING PROBLEMS IN GROUP TECHNOLOGY WITH DETERIORATING JOBS

This paper considers single-machine scheduling problems in group technology with the jobs' processing times being simple linear functions of their start times.The objective functions are the ~minimizing of makespan and total weighted completion time.Some optimal conditions and algorithms are given and the fact that the problem of total weighted completion times is NP-hard is proved.

Product Drawing Management System Based on Group Technology

With the development and widely used of the compute r technology, the CAD has been more and more used in the process of designing prod uct. The number of the engineering drawings will greatly increase because of the continually appearance of the new products. As a result, it has become a badly needed to be solved problem for us that how to rapidly and efficiently search an d appropriately preserve and manage the drawings. In this paper, a method of bui lding the product drawing management system for extrusion aluminum-type materia ls is discussed. This system is designed for the profile graphic of the aluminou s section material management by using Group Technology (GT) principle. Accordin g to the GT, we developed a classifying-coding system and drawing management sy stem about the extrusion aluminum-type materials through analyzing a large numb er of extrusion aluminum-type materials section drawings. The coding system has realized the flexible coding and hidden coding of the extrusion aluminum-type materials and then enhanced the flexibility and the expansible of the system. By supplying the designer with the human-computer interaction interface the drawi ng management system has been able to resolve many difficult problems such as se arch and manage the existed drawings about the extrusion aluminum-type material s very well. At the same time, it also helps the developing work enhance the abi lity of inheriting by applying this kind of variant method. In a word, with the help of this system we can not only shorten the designing time greatly and reduc e the cost of the product but also research the designing drawings rapidly. In o rder to output the data information related to the part drawing, the system uses the data-exchange standard to which the drawing support-software adapted as d ata-exchange interface. The system is advantageous to building a standard of dr awing design and increasing the efficiency of searching drawing and enhancing th e information management, which have had a base for building the best management system in the future. In addition, the paper has a detailed analysis about the principle of flexible classification code and data structure.

Concept,Grouping and Subgrouping of Ecological Technology

Although modern technology has an important role in human economic and social development,it can result in significant ecological damage.Thus,research has begun to focus on so-called"ecological technologies"to repair the degraded land and fragmented ecological environment and build a green mode of production and development.However,the concept of"ecological technology"is currently ill-defined,given the many different research fields involved.Therefore,here we divide ecological technologies into broad versus narrow technologies in terms of their impact on economic and social development and the related needs of production and ecological governance.We redefine each concept and clarify their aims and extensions,before further dividing them into three groups and seven subgroups,and clarifying the functions of each.The grouping and subgrouping of ecological technology will lay a foundation for the technology selection,collocation,implementation,promotion,monitoring and evaluation of ecological engineering planning and design.

CNTIC Group Developing Technology Trade

Formally founded at the end of 1994,the CNTIC (China NationalTechnical Import ＆ Export Corporation)Group specializes in exporting high-tech,complete plant equipment and mechanicaland electrical products. The group is anexport-oriented enterprise groupcharacterized by technology trade, itsoperating content represents thedevelopmental direction of the exportindustry in China and its founding was ofgreat significance in expanding the exportof technology-intensive products andpromoting domestic scientific andtechnological progress.

Study on the general layout of semi-submersible offshore drilling platforms based on process flow

The general layout of 6th generation semi-submersible drilling platforms is the main factor impacting the efficiency of their drilling operations. This paper provides a compound/integrated algorithm based on process flow that is aimed at improving efficiency, while giving attention to stability and safety at the same time. The paper describes the process flow of dual drilling centers and a hierarchical division of rigs based on the different modes of transportation of various drilling support systems. The general layout-centripetal overall arrangement spatially was determined based on drilling efficiency. We derived our modules according to drilling functionality; the modules became our basic layout units. We applied different layout algorithm to mark out the upper and lower decks. That is, the upper deck was designed based on the lowest transportation cost while the lower deck＇s calculations were based on the best-fit scope. Storage configurations in columns and pontoons were also considered for the layout design. Finally the center of gravity was taken into consideration and the general layout was adjusted accordingly, to result in an optimal center of gravity. The methodology of the general layout can provide a reference for implementation of domestic designs of semi-submersible rigs.

Merging Functional Form Feature into GT Codes to Enhance the CAD/CAM Integration

The TangShan Research Institute of Group Technology has been engaged in the develop- ment of GT for the light industry machinery building factories since 1980.Under its overall supervision more than 8 factories have applied GT to drawing control and process planning,while 4 of them reorga- nized their machine shops into GT cells and the throughput capabilities were raisd immediately by 15 to even 49%. Since the existing GT coding systems predict only the global characteristics of machine parts,their application alone is unable to transfer all the information needed for the CAD/CAM integration in a CIM environment.From the very beginning of 1989,we started to study the feasibility of introducing concepts of Functional Form Features into GT codes.Based on the exhaustive study of nearly 100,000 part drawings from machineries for making pottery and porcelain appliances,cigarette,paper pulp, glass bottles,plastics moulding,beer and beverage filling etc.,a new GT/FFF coding system was worked out and a corresponding set of standard drawings assembled from FFF primitives Was formulat- ed which can cover up to 65—75% of existing parts from light industry machineries.FFF based GT codes greatly facilitate the standardization control of released drawings,accelerate the engineering de- sign and process planning,and certainly will play an important role in the future CIM organization.

Research on a New Coding System for Vibrating Feeder Design

The sUdeway design is the key in the design of the disc vibrating feeder. However, no reliable theoretical guidance has come into existence, which greatly restricted the application of CAD（ Computer-aided design）. In order to feed the application of CAD technology, we must make improvements to the existing coding method. Based on the similarity principle of Group Technology and existing coding system, a new coding method applicable to slide- way design is brought forward. The existing coding system could get optimized by means of analysing and studying the influence imposed by the parts＇ shape and posture features. More detailed information about the parts could be supplied by the new coding system, which makes the design simpler, more convenient and more accurate with the subjoin of the initial and targeted codes.

A Novel Approach to Solve the FMS Formation Problem

We propose in this paper a genetic algorithm (GA)-based approach to solve the Flexible Manufacturing System (FMS) formation problem. First, we divide the unity of machines into small groups or cells using Group Technology (GT). And an option for considering the minimization of workload variation between cells is included. Then the implementation is done using GA. When using GA, the designer is allowed to specify the number of cells and impose lower and upper bounds on cell size. This makes the GA scheme flexible for solving the FMS formation problems.

Group Stars of Science and Technology in Wuhan

Wuhan University graduates are filling many useful and productive roles in society. Shown here is the university president, Tao Delin (Front 8th R.).

Dow and Davy License LP OxoSM Technology to Lihuayi Group in China

On June 18th,LP OxoSM SELECTORSM Technology,which is cooperatively of-fered by Dow Technology Licensing,a business unit of The Dow Chemical Company and its consolidated affiliates (Dow),and Davy Process Technology Limited,a Johnson Matthey company,has been selected by Lihuayi Group in China for a new 250

An Integrated Application of Neural Network ,Fuzzy and Expert Systems for Machining Operation Sequencing

Apartis described using features.Aneuro fuzzy system then determines the machining sequence for each feature.Previous process plans were utilized to build,test,and validate the Neuro Fuzzy Network (NFN). Parts having similar manufacturing sequences are grouped into families, also using an NFN. A standard manufacturing sequenceis obtained for each family comprising allthe operations applicable to the features ofthe partsinthefamily.An expertsystem then adaptsthisstandard sequence forthe particular partbeing planned.Theoptimaloperation sequenceisinherited by the new part.The procedure is demonstrated by an example industrial part.