Concept Validation for Selective Heating and Press Hardening of Automotive Safety Components with Tailored Properties

© (2014) Trans Tech Publications, Switzerland.A new strategy termed selective heating and press hardening, for hot stamping of boron steel parts with tailored properties is proposed in this paper. Feasibility studies were carried out through a specially designed experimental programme. The main aim was to validate the strategy and demonstrate its potential for structural optimisation. In the work, a lab-scale demonstrator part was designed, and relevant manufacturing and property-assessment processes were defined. A heating technique and selective-heating rigs were designed to enable certain microstructural distributions in blanks to be obtained. A hot stamping tool set was designed for forming and quenching the parts. Demonstrator parts of full martensite phase, full initial phase, and differentially graded microstructures have been formed with high dimensional quality. Hardness testing and three point bending tests were conducted to assess the microstructure distribution and load bearing performance of the as-formed parts, respectively. The feasibility of the concept has been validated by the testing results

Routing issues for dynamic networks

The routing is one very important function implemented in computer communication networks. It collects information about optimal paths within a network;The purpose of this dissertation is to study the routing function in large networks which are characterized by frequent topological changes. The study focuses on constructing routing protocols with some desirable properties such as distributed computation, adaptation to flow variations within the network, failsafe against arbitrary topological changes, loop-free route tables for all destinations at all times, bounded values for variables, and fast recovery from topological changes;At present, most routing protocols use the next-node routing technique, a technique in which each node keeps only the next node identification for a particular destination. A different type of routing scheme provided in some protocol standards is called source routing. A source routing protocol builds complete paths from a source to all destinations in the network. Several source routing algorithms are derived with desirable properties;Most distributed routing algorithms use one or more variables to store unbounded values such as update cycle numbers. Distributed routing protocols with bounded update cycle numbers are proposed. The proposed protocols possess desirable properties and are obtained by applying the sliding window idea for flow control in networks to the routing protocols which employ unbounded update cycle numbers;How fast an algorithm provides optimal paths from every node to every other node in a network after a topological change is an important consideration in the design of routing algorithms. Several algorithms for achieving shortest paths to all destinations in the network with improved recovery speed from topological changes are presented

Life-style orientation and contents of websites in personas industry

Electronic commerce challenges personas companies to design electronic system to increase interaction which leads to retain customers and increase sales. This exploratory study examines the correlation between lifestyle and emphasis on contents of website in personas industry. The study finds that market segment of lifestyle can be divided into four groups: ‘opinion leader’, ‘opinion follower’, ‘conservative’ and ‘challenger’. This paper tries to suggest a checklist to a vendor. We conclude that AIO can be a base of market segment in personas industry. We suggest some important factors which are included of the customized services, the safety of use factors, the store information and the menu illustration. Finally, we also conclude that the first three important factors of websites have significant influences on market segments of personas industry except for the store information factor.AIO, market segmentation, personas industry.

A Shared Information-Based Petri Net Model for Service Parts Planning

A considerable amount of electronic products are returned after sales, especially in such an economic downturn situation. After repair and refurbishment, the used products can be returned into the markets which fulfill the forward supply chains into a close loop. In this paper, we consider the service parts planning in the beginning of product rolling plan together with the sales through quantities to minimize the inventory level in the period of product lifecycle. A Petri Net is used to model a simple closed-loop supply chain with shared sales information. PUSH and PULL inventory policies are used in this research. Finally, it is investigated how a third party service provider uses this mechanism to improve the accuracy of inventory planning

Coronary Artery Ectasia Presenting With Recurrent Inferior Wall Myocardial Infarction

AbstractCoronary ectasia presenting as a recurrent inferior myocardial infarction has rarely been reported in the literature. Herein, we report a 61-year-old man who presented with persistent chest pain accompanied by ST segment elevation in the inferior ECG leads. Coronary angiography showed ectasia of the right coronary artery (RCA) and total occlusion from the middle RCA. Two stents were implanted separately in the middle and distal RCA. The patient was readmitted due to recurrent inferior wall infarction 15 months after discharge. He underwent primary percutaneous coronary intervention again, and coronary angiography showed massive thrombosis and in-stent re-stenosis. The thrombosis and re-stenosis were successfully treated using balloon angioplasty. The patient was discharged under medical therapy with aspirin and clopidogrel. There were no anginal symptoms during the 3 years of follow up

TEST-RETEST RELIABILITY OF PAIRED PREFERENCE TEST FOR THE WEIGHTED SHOES

The purpose of this study was to examine the test-retest reliability of paired preference test for the weighted shoes. Forty participants were recruited and instructed to put on the weighted shoes and choose the preferred one after completing four paired comparisons. During the tests, participants were blind of any information from the shoes. All the participants were invited to repeat the same procedure one week after the first session. The results in first session showed that thirty-two (80%) out of the forty participants preferred Shoe D or E, which centre of mass was close to the rear end of the shoe. The greater intra-class correlation coefficient (ICC=0.81) represents the perfect test-retest reliability of the paired preference test. The test protocol designed in this study could apparently reduce the numbers of the paired comparison under the characteristic of the testing shoe varied systematically, for example the weighted shoes used in this study