Computer Aided Design

We study theI-Vcharacteristic of mesoscopic systems or quantum dot (QD) attached to a pair of superconducting leads. Interaction effects in the QD are considered through the charging energy of the QD; that is, the treatment of current transport under a voltage bias is performed within a coupled Poisson nonequilibrium Green function (PNEGF) formalism. We derive the expression for the current in full generality but consider only the regime where transport occurs only via a single particle current. We show for this case and for various charging energies valuesU0and associated capacitances of the QD the effect on theI-Vcharacteristic. Also the influence of the coupling constants on theI-Vcharacteristic is investigated. Our approach puts forward a novel interpretation of experiments in the strong Coulomb regime.

The aim of this study was to evaluate whether the introduction of a device, resulting from the combination of an o'ring attachment with an orthodontic implant (o'ring ortho implant, O'ROI), to affix the surgical template of CAD/CAM-guided implant surgery contribute to minimizing the deviations in the position and inclination of implants at the time of their placement. Ten models simulating bone tissue were fabricated and randomly divided into 2 groups: 5 with the scanning and surgical template of the usual technique, representing the Control Group (C), and 5 with scanning and surgical templates fixed by o'ring ortho implants (O'ROI), representing the Test Group (T). Forty implants measuring 4×11 mm were placed in the groups, using the respective templates. The results were evaluated by the fusion of CT images of the planned and placed implants. The locations and axes were compared. There were no statistically significant differences for the angular (Tukey's t...

This study focuses on the artworks of artist-academic İlker Yardımcı. The perspective put forward in the study is built on the aesthetic status of the scientific and technological aspects of İlker Yardımcı's artwork. Based on this context, a research has been done on the relationships between art and science. Various examples have been given from the times when art and science were seen as a whole and did not dissociate, and the development and separation process of these two separate phenomena were approached from various angles. In this way, in the light of the information obtained from the research, an aesthetic understanding that is open to the effects of science and technology, combining technological possibilities with traditional structures has been tried to be determined. Through this way, the possibility of an aesthetic narration was opened on the situation in the sculptures of İlker Yardımcı. Thus, the traces of the aesthetics in these sculptures, including science, were deciphered.

In this article, performance of 70 W, 350 rpm, axial-field and radial-field permanent magnet brushless dc motors is compared using computer aided design (CAD) and finite element (FE) methods. The design variables like number of poles, slots per pole per phase, airgap length, airgap flux density, slot electric loading, stator flux density, and the permanent magnet material are changed one at a time and the performances are calculated using the developed CAD program. The CAD results are validated by carrying out two-dimensional and three-dimensional FE analyses. It is observed that the axial-field motor gives higher efficiency, whereas the radial-field motor has less weight.

The restoration of anterior teeth is a difficult task, even for an experienced operator. Currently there are many different ceramic systems that can be used to achieve highly esthetic results. These include metal-ceramics with porcelain margins, Dicor, In-Ceram, Cerestore, Hi-Ceram, IPS-Empress, Cerapearl, Optec, and CAD/CAM ceramics. While metal-ceramics have been used for more than four decades, the quest for a material that transmits and refracts light like a natural tooth has inspired research into all-ceramic restorations. The purpose of this paper is to briefly discuss the properties of each of the above-mentioned materials and clinically evaluate the optical behavior of: (1) metal-ceramic crowns with castings 2 mm short of the shoulder preparation and 360-degree porcelain margins; (2) In-Ceram Spinell restorations; and (3) IPS Empress restorations, and to compare these with metal-ceramic crowns with copings to the shoulder preparation and 180-degree porcelain margins. Light t...

Selective Laser Sintering (SLS) produces three-dimensional objects directly from a computer-aided design (CAD) solid model, without part-specific tooling, by repeatedly depositing thin layers of fusible powder and selectively sintering each layer to the next with a ...

Replacement of lost teeth using oral implants is an accepted treatment modality with well-documented high long-term success rates. Conventional screw- or threaded cylinder-type implants have been used almost exclusively. Their incongruence with the extraction socket necessitates the use of a barrier membrane or bone augmentation to prevent down-growth of connective tissue or epithelium between the implant and socket. Although some minor changes in implant design have been made, the neck and abutment connection areas have not changed much in the past 30 years. Custom-made root analog implants have been employed clinically in rare instances; however, they yielded failure rates of up to 96% at 1 year of follow-up. So far, ovoid implants are the closest in design regarding resemblance to the natural tooth anatomy. Root analog zirconia implants with macroretentions were developed and produced for immediate single-stage replacement of missing or hopeless teeth. This article discusses the ...

Recently, several theoretical papers have derived relationships for fiber-optic transmission system performance in terms of associated physical layer parameters. At the same time, a large number of detailed experiments have been and continue being performed that demonstrate increasing capacities and unregenerated reach. We use this wealth of experimental data to validate the aforementioned relationships, and to propose a set of simple scaling rules for performance. We find that, despite substantial differences in experimental configurations, overall performance in terms of spectral efficiency and unregenerated reach is well explained by scaling rules. These scaling rules will be useful to carriers seeking to understand what they should expect to see in terms of network performance using deployed or easily accessible technology, which may be radically different from hero experiment results. These rules will also be useful to design engineers seeking cost effective tradeoffs to achiev...

Purpose: The aim of this study was to determine effect of compressive cyclic loading on fatigue resistance and microleakage of monolithic CAD/CAM molar ceramic and composite crowns. Materials and Methods: Thirty-two extracted molars were prepared to receive ...

In Life Cycle Engineering, it is vital that the engineering knowledge for the product is captured throughout its life cycle in a formal and structured manner. This will allow the information to be referred to in the future by engineers who did not work on the original design but are wanting to understand the reasons that certain design decisions were made. In the past, attempts were made to try to capture this knowledge by having the engineer record the knowledge manually during a design session. However, this is not only time-consuming but is also disruptive to the creative process. Therefore, the research presented in this paper is concerned with capturing design knowledge automatically using a traditional 2D design environment and also an immersive 3D design environment. The design knowledge is captured by continuously and non-intrusively logging the user during a design session and then storing this output in a structured eXtensible Markup Language (XML) format. Next, the XML da...

Geometric computing is a rapidly evolving interdisciplinary field involving computer science, engineering and mathematics. It has relationships to many other areas within computer science such as computational geometry, computer-aided design, computer graphics, computer ...

Project management are still depending on manual exchange of information based on paper documents. Where design drawings drafting by computer-aided design (CAD), but the data needed by project management software can not be extracted directly from CAD, and must be manually entered by the user. The process of calculation and collection of information from drawings and enter in the project management software needs effort and time with the possibility of errors in the transfer and enter of information. This research presents an integrated computer system for building projects where the extraction and import quantities, through the interpretation of AutoCAD drawing with MS Access database of unit costs and productivities for the pricing and duration of tasks, then exported to MS Project and MS Excel. The system was developed by using Visual Basic and ActiveX automation technology for combining the above software. The system, also, can calculate quantities of materials. The system includes digitizer (on-screen takeoff) calculates the lengths and areas of the drawings to which the form of an image and scanned. The integrated system has been applied to case study, a storages building for hospital 260 beds. The results proved the effectiveness of the system for the conversion of information from the graphical form dwg to numerical formulas xlcx / xlc and mpp can be handled easily pleased and software are covered.

We envision cobotic infinitely-variable transmissions (IVTs) as an enabling technology for haptics and prosthetics that will allow for increases in the dynamic range of these devices while simultaneously permitting reductions in actuator size and power requirements. Use of cobotic IVTs eliminates the need to make compromises on output flow and effort, which are inherent to choosing a fixed transmission ratio drivetrain. The result is a mechanism with enhanced dynamic range that extends continuously from a completely clutched state to a highly backdrivable state. This high dynamic range allows cobotic devices to control impedance with a high level of fidelity. In this paper, we discuss these and other motivations for using parallel cobotic transmission architecture in prosthetic devices.

Scientists and policymakers intend worldwide emissions reduction of up to 80 percent of carbon dioxide (CO2) and other greenhouse gases (GHGs) in the next four decades to stabilize atmospheric concentrations (TRB 2011). Henceforth, an immediate response from the transportation sector, one of the largest producers of GHGs (up to 30 percent in the U.S.), is critical for GHGs reduction. Possible long-term solutions towards cutting back on emissions from transportation are increasing supply-of/demand-for more energy/fuel efficient vehicles and to substantially improve the transit system (high-speed rail, passenger rail, metro) to reduce reliance on private vehicles and air travel for short trips. However, the markets are still struggling to produce supply-of/demand-for energy efficient vehicles and public debate on potential ridership of high speed rail is ongoing in the U.S. Another feasible strategy that can prove to be effective is emission pricing. Recent advancement in Intelligent ...

This study is concerned with exploring students’ use of CAAD software programs, which are already available in studios and schools of architecture - to better reflect the status of CAAD in the educational context of the studio where CAAD is not an integral part of studio teaching. This study also anticipated providing a “real-context” appraisal for CAAD related issues and to know what is behind the tendency to use CAAD early in the conceptual phases of the design process. At the general level of inquiry, a questionnaire survey was designed and circulated. Also, by directly observing studio activities, the study can develop an understanding of the modern context within which the study operates. This included interviewing students through part of their design reflection at the studio and acting on those observations from a process methodological point of view. This study was able to clarify the effects of computers on the traditional context of the architectural studio, and how this w...

Abstract: In Malaysia, the rapid increase in the use of own transport prompted by inadequate public transport has resulted in increased traffic congestion, accidents, inadequate parking space and air pollution among other evils. This study sought to identify the factors preventing own transport users from shifting to public transport and to develop model shift from car to public transport in order to formulate the policies to achieve this. A survey was carried out on users of private and public (both bus and urban train transport)(n= 1350). Multinomial legit ...