Benefit Evaluation for Manufacturing of Marine Propellers

2008 ◽  
Author(s):  
Der-Min Tsay ◽  
Hsin-Pao Chen ◽  
Sa´ndor Vajna ◽  
Michael Schabacker
Keyword(s):  
Cost Model ◽  
Cost Savings ◽  
Machining Efficiency ◽  
Machining Time ◽  
Marine Propellers ◽  
Tool Paths ◽  
Benefit Evaluation ◽  
Cad Cam ◽  
Increase Productivity ◽  
The Cost

To increase productivity of marine propellers by raising machining efficiency, this paper presents the zigzag/spiral tool paths generation algorithm based on the arc base curve approach for three-axis machining of curved surfaces of propellers. By considering the shapes of selected cutters with different types of tool paths generated by the proposed procedure, machining efficiency can be calculated and simulated. To verify the accuracy and effectiveness of the developed approach, numerical and experimental results of machining of propeller surfaces are compared. It was proved that the machining time can be cut down up to 19% by using zigzag tool paths with a toroidal cutter. In addition, the machining knowledge revealed here can be accumulated for benefit evaluation in the manufacturing process with existing CAD/CAM systems. From the cost model, design, and process views, the overall cost savings after 5 years are investigated, and the expected benefit yield is about 45%.

Oral Antibiotic Management of Acute Osteomyelitis of the Hand: Outcomes and Cost Comparison to Standard Intravenous Regimen

Hand ◽  
2019 ◽  
pp. 155894471987314
Author(s):  
Mark Henry ◽  
Forrest H. Lundy
Keyword(s):  
Bone Loss ◽  
Direct Cost ◽  
Cost Model ◽  
Cost Savings ◽  
Cost Of Care ◽  
Cost Comparison ◽  
Study Cohort ◽  
Oral Antibiotic ◽  
Direct Inoculation ◽  
The Cost

Background: Acute, direct inoculation osteomyelitis of the hand has traditionally been managed by intravenous antibiotics. With proven high levels of bone and joint penetration, specific oral antimicrobials may deliver clinical efficacy but at substantially lower cost. Methods: Sixty-nine adult patients with surgically proven acute, direct inoculation osteomyelitis of the hand were evaluated for clinical response on a 6-week postdebridement regimen of susceptibility-matched oral antibiotics. Inclusion required gross purulence and bone loss demonstrated at the initial debridement and radiographic evidence of bone loss. Excluded were 2 patients with extreme medical comorbidities. There were 53 men and 16 women with a mean age of 46 years. Mean follow-up was 16 weeks (±10). The cost model for the outpatient oral antibiotic treatment was intentionally maximized using Walgreen’s undiscounted cash price. The cost model for the traditional intravenous treatment regimen was intentionally minimized using the fully discounted Medicare fee schedule. Results: All patients achieved resolution of osteomyelitis by clinical and radiographic criteria. In addition, 7 patients underwent successful subsequent osteosynthesis procedures at the previously affected site without reactivation. The mean postdebridement direct cost of care per patient in the study cohort was $482.85, the cost of the antibiotic alone. The postdebridement direct cost of care per patient on a regimen of vancomycin 1.5 g every 12 hours via peripherally inserted central catheter line was $21 646.90. Conclusions: Acute, direct inoculation osteomyelitis of the hand can be successfully managed on oral antibiotic agents with substantial direct and indirect cost savings.

Cost assessment of multi-tenancy for a 5G broadband network in a dense urban area

2020 ◽  
Vol 22 (2) ◽  
pp. 53-70
Author(s):  
Juan Rendon Schneir ◽  
Konstantinos Konstantinou ◽  
Julie Bradford ◽  
Gerd Zimmermann ◽  
Heinz Droste ◽  
...  
Keyword(s):  
Cost Model ◽  
Access Network ◽  
Cost Savings ◽  
Economic Benefits ◽  
Mobile Service ◽  
Content Type ◽  
Broadband Network ◽  
Cost Implications ◽  
The Cost ◽  
Network Sharing

Purpose 5G systems will enable an improved transmission performance and the delivery of advanced communication services. To meet the expected requirements, operators will need to invest in network modernisation, with the radio access network being the most expensive network component. One possible way for operators to reduce this investment would be via sharing of resources by means of a multi-tenancy concept. This implies that a mobile service provider may use the common infrastructure of one or various infrastructure providers, whereby it provides services to multiple tenants. This paper aims to study the expected cost savings in terms of capital expenditures (CAPEX) and operational expenditures (OPEX) that can be achieved when using a cloudified 5G multi-tenant network. Design/methodology/approach A cost model was used. The study period is 2020-2030 and the study area consists of three local districts in central London, UK. Findings This paper describes that the total cost reduction achieved when using multi-tenancy for a 5G broadband network in comparison with the case where operators make the investment independently ranges from 5.2% to 15.5%. Research limitations/implications Further research is needed to assess the cost implications of network sharing for 5G on a regional or nationwide basis. Originality/value Very little quantitative research about the cost implications of network sharing under 5G networks has been published so far. This paper sheds light on the economic benefits of multi-tenancy in a 5G broadband network.

Compensating Cleanup Tool Path

1998 ◽  
Author(s):  
Xiaohong Zhu ◽  
Richard F. Riesenfeld
Keyword(s):  
Tool Path ◽  
Machining Process ◽  
Process Efficiency ◽  
Shop Floor ◽  
Machining Time ◽  
Motion Constraints ◽  
Tool Paths ◽  
Cad Cam ◽  
Computationally Intensive ◽  
Increase Tool Life

Abstract Today’s part geometries are becoming ever more complex and require more accurate tool path to manufacture. Machining process efficiency is also a major consideration for designers as well as manufacturing engineers. Although the current advanced CAD/CAM systems have greatly improved the efficiency and accuracy of machining with the introduction of Numerically–Controlled machining, excessive material may still be left on the finished part due to machining constraints, including the inaccessibility of the designed part geometry with respect the cutter, machine motion constraints like ramp angles, specific cutting patterns, etc. Polishing operations such as grinding and hand finishing are quite time consuming and expensive, and may damage the surface of the part or introduce inaccuracies because of human errors. While most of the existing machining approaches attempt to reduce such excessive restmaterials by modifying NC tool paths, none of them is satisfactory. They can be time–consuming, error prone, computationally intensive, too complicated to implement, and limited to certain problem domains. A compensating cleanup tool path will be developed in this research to automatically remove these excessive material from the finish part. This method greatly reduces the burden of hand finishing and polishing, and also reduces the error and complexities introduced in manually generating cleanup tool paths in the shop floor. More important, the tool path generated by this method will reduce the machining time, and increase tool life compared with optimized tool path which left no excessive material behind.

scholarly journals Development of Direction-Parallel Strategy for Shorting A Tool Path in The Triangular Pocket Machining

2019 ◽  
Vol 18 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Mochammad Chaeron ◽  
Budi Saputro Wahyuaji ◽  
Apriani Soepardi
Keyword(s):  
Path Length ◽  
Tool Path ◽  
Machining Efficiency ◽  
Machining Time ◽  
Pocket Machining ◽  
Direction Parallel ◽  
Numerical Examples ◽  
Tool Paths ◽  
Machining Strategy ◽  
Parallel Strategy

The machining strategy is one of the parameters which practically influences the time of the different manufacturing geometric forms. The machining time directly relates to the machining efficiency of the tool paths. In area milling machining, there are two main types of tool path strategies: a direction-parallel milling and contour-parallel milling. Then direction-parallel milling is simple compared with a contour-parallel strategy. This paper proposes a new model of the direction-parallel machining strategy for triangular pockets to reduce the tool path length. The authors develop an analytical model by appending additional the tool path segments to the basis tool path for cutting un-machined area or scallops, which remained along the boundary. To validate its results, the researchers have compared them to the existing model found in the literature. For illustrating the computation of this model, the study includes two numerical examples. The results show that the proposed analytic direction-parallel model can reduce the total length of machining. Thus, it can take a shorter time for milling machining.

Time-Efficient Trochoidal Tool Path Generation for Milling Arbitrary Curved Slots

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Ke Xu ◽  
Baohai Wu ◽  
Zhaoyu Li ◽  
Kai Tang
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Removal Rate ◽  
Machining Efficiency ◽  
Machining Time ◽  
Tool Paths ◽  
Engagement Angle ◽  
New Type ◽  
The Given ◽  
Slot Cutting

Trochoidal (TR) tool paths have been a popular means in high-speed machining for slot cutting, owing to its unique way of cyclically advancing the tool to avoid the situation of a full tool engagement angle suffered by the conventional type of slot cutting. However, advantageous in lowering the tool engagement angle, they sacrifice in machining efficiency—to limit the tool engagement angle, the step distance has to be carefully controlled, thus resulting in a much longer total machining time. Toward the objective of improving the machining efficiency, in this paper, we propose a new type of TR tool path for milling an arbitrary curved slot. For our new type of TR tool path, within each TR cycle, rather than moving circularly, the tool moves in a particular way such that the material removal rate is maximized while the given maximum engagement angle is fully respected. While this type of TR tool path works perfectly only for circular slots (including straight ones), by means of an adaptive decomposition and then a novel iso-arc-length mapping scheme, it is successfully applied to any general arbitrarily curved slot. Our experiments have confirmed that, when compared with the conventional TR tool paths, the proposed new type of TR tool path is able to significantly reduce the total machining time by as much as 25%, without sacrificing the tool wear.

A Dedicated CAD/CAM System for 5-Axis Machining of Marine Propeller

2001 ◽  
Author(s):  
Jae-Woong Youn ◽  
Yongtae Jun ◽  
Sehyung Park
Keyword(s):  
Lead Time ◽  
Tool Path ◽  
General Purpose ◽  
Tool Path Generation ◽  
Path Generation ◽  
Marine Propeller ◽  
Marine Propellers ◽  
Tool Paths ◽  
System Validation ◽  
Cad Cam

Abstract The manufacture of a marine propeller typically requires long lead-time to generate 5-axis tool paths. It usually takes several days to manufacture a satisfactory propeller with a general purpose CAD/CAM system. This paper proposes a novel methodology for tool path generation of 5-axis machining of marine propellers. Using the geometric characteristics of propellers, the system first computes check vectors and then generates interference-free tool paths. An iterative NURBS modeling technique is used to improve the accuracy of the models and to increase the productivity. The system has been implemented with C++ and OpenGL graphic library on the Windows system. The system validation and sample results are also given and discussed.

Computer Aided Manufacturing of Marine Propellers by Parallel Kinematics Machine

Materials ◽  
2003 ◽  
Author(s):  
Hui Chen ◽  
Zhixing Wang
Keyword(s):  
Tool Path ◽  
Parallel Kinematics ◽  
Dimensional Model ◽  
Computer Aided Manufacturing ◽  
3 Dimensional ◽  
Marine Propellers ◽  
Tool Paths ◽  
Nc Program ◽  
Computer Aided ◽  
Cad Cam

Techniques of manufacturing integral marine propellers by Parallel Kinematics Machine (PKM) are discussed in this paper, and complete CAD/CAM steps for manufacturing propellers using UG CAD/CAM system are presented. The designed propeller model is defined by a series of aerofoil sections data, so UG/CAD module are used to create the 3-dimensional model of propeller, and tool paths are generated in UG/CAM module. Vericut is adopted to simulate the tool paths generated by UG/CAM and to check interferences. NC postprocessor for PKM is developed on the basis of UG/Post. It is invoked in UG/CAM and converts tool path data into NC program to drive PKM. Finally, machining experiments based on all the techniques discussed in this paper are made. Not only does it puts forward a new scheme and machine to manufacture marine propellers, but also can push the industrialization and practicality of PKM.

scholarly journals Redesign of an upwind rotor for a downwind configuration: design changes and cost evaluation

2021 ◽  
Vol 6 (1) ◽  
pp. 203-220
Author(s):  
Gesine Wanke ◽  
Leonardo Bergami ◽  
Frederik Zahle ◽  
David Robert Verelst
Keyword(s):  
Cost Model ◽  
Cost Savings ◽  
Rotor Blades ◽  
Cost Evaluation ◽  
Potential Cost ◽  
Pure Material ◽  
Cost Of Energy ◽  
Design Changes ◽  
The Cost ◽  
The Impact

Abstract. Within this work, an existing model of a Suzlon S111 2.1 MW turbine is used to estimate potential cost savings when the conventional upwind rotor concept is changed into a downwind rotor concept. A design framework is used to get realistic design updates for the upwind configuration, as well as two design updates for the downwind configuration, including a pure material cost out of the rotor blades and a new planform design. A full design load basis according to the standard has been used to evaluate the impact of the redesigns on the loads. A detailed cost model with load scaling is used to estimate the impact of the design changes on the turbine costs and the cost of energy. It is shown that generally lower blade mass of up to 5 % less than the upwind redesign can be achieved with the downwind configurations. Compared to an upwind baseline, the upwind redesign shows an estimated cost of energy reduction of 2.3 %, and the downwind designs achieve a maximum reduction of 1.3 %.

Proactive Cost Impact Assessments of Design Alternatives

2004 ◽  
Author(s):  
Joseph P. Falque
Keyword(s):  
Impact Assessment ◽  
Real Time ◽  
Real World ◽  
Cost Model ◽  
Cost Savings ◽  
Time Cost ◽  
Substantial Cost ◽  
Cost Impact ◽  
Design Alternatives ◽  
The Cost

This paper discusses how a process-based parametric cost model, SEER-DFM, is used to facilitate the proactive real time cost impact assessment of composite and metallic design alternatives. The main purpose is to introduce the underlying methodology and demonstrate the flexibility of the cost model for developing trade studies. Readers are introduced to the model, its premise, and how engineers use it to obtain substantial cost savings through ‘real world’ cases.

Preview

2010 ◽  
pp. 47-63
Author(s):  
Songmei Yu ◽  
Vijayalakshmi Atluri ◽  
Nabil Adam
Keyword(s):  
Data Warehouse ◽  
Spatial Data ◽  
Cost Model ◽  
Cost Savings ◽  
Maintenance Cost ◽  
Materialized View ◽  
Spatial Part ◽  
Spatial Data Warehouse ◽  
Composite Lattice ◽  
The Cost

One of the major challenges facing a data warehouse is to improve the query response time while keeping the maintenance cost to a minimum. Recent solutions to tackle this problem suggest to selectively materialize certain views and compute the remaining views on-the-fly, so that the cost is optimized. Unfortunately, in the case of a spatial data warehouse, both the view materialization cost and the onthe- fly computation cost are often extremely high. This is due to the fact that spatial data are larger in size and spatial operations are more complex than the traditional relational operations. In this chapter, the authors propose a new notion, called preview, for which both the materialization and on-the-fly costs are significantly smaller than those of the traditional views. Essentially, to achieve these cost savings, a preview pre-processes the non-spatial part of the query, and maintains pointers to the spatial data. In addition, it exploits the hierarchical relationships among the different views by maintaining a universal composite lattice, and mapping each view onto it. The authors present a cost model to optimally decompose a spatial query into three components, the preview part, the materialized view part and the on-the-fly computation part, so that the total cost is minimized. They demonstrate the cost savings with realistic query scenarios, and implement their method to show the optimal cost savings.

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