Desired Design Criteria Research Articles

New Asynchronous Channel-Hopping Sequences for Cognitive-Radio Wireless Networks

In this paper, one family of identification-(ID)-based and one family of non-ID-based asynchronous channel-hopping (CH) sequences are constructed for supporting cognitive-radio wireless networks (CRWNs) in a homogeneous channel setting. The novelty lies in the use of two-dimensional (2-D) algebraic algorithms to properly arrange the linear- and quadratic-congruence sequences in the prime field; channel rendezvous are guaranteed to occur among all the elements (i.e., licensed channels) in at least one of the columns between any two CH matrices. As a result, the new asynchronous CH sequences always have uniform time-to-rendezvous (TTR) structures and satisfy the desirable design criteria of short periods, full degree-of-rendezvous (DoR), and even channel use (ECU). The studies show that the new constructions have the best balance between the full DoR, ECU, short period, small TTR mean and variance, and shortest maximum-time-to-rendezvous (MTTR) and maximum-first-time-to-rendezvous (MFTTR) in their respective categories of constructions. A short period can save memory in small sensors and mobile devices and are suitable for the Internet-of-Things and device-to-device communications. A short MTTR/MFTTR and a small TTR mean/variance can improve the rendezvous frequency and shorten the latency, thus enhancing and stabilizing the throughput.

Design of autopilot control system on unmanned surface vehicle type monohull LSS-01 using model reference adaptive control-state feedback in waypoint control

For unmanned surface vehicle to run automatically, algorithms of the autopilot system and waypoint navigation are needed. The autopilot system is an unmanned surface vehicle control towards the waypoint. One example of a navigation algorithm is the desired waypoint, it requires control of the ship's steering angle, namely thrust and turning angle. Unmanned surface vehicle can encounter external interference while advancing, such as waves, wind, and ocean currents. It is desirable, therefore, to unmanned surface vehicle to be able of adapting these conditions. One way to overcome this interference is to design adaptive controllers such as the Model Reference Adaptive Control (MRAC) - state feedback to regulate the behavior of unmanned surface vehicle plants. In this respect a reference to the desired model is required for the MRAC-state feedback controller. Using this method, it is expected that unmanned surface vehicle can move accurately from the expected waypoint. The MRAC-state feedback controller can produce an angle response of unmanned surface vehicle and speed on the surge axis according to the desired design criteria. From the simulation carried out the adaptive gain that is suitable for LSS01 unmanned surface vehicle is 0.0001. The results of simulation on the ship headed waypoint cross-track show RMS error when uninterrupted is 0.0846 and when given a disturbance is 0.2969.

Numerical Analysis of Lattice Structures for Skin Layer in Camber Morphing Wing

Unlike conventional fixed wings and their static skin structure considering only expected aerodynamic loadings while filight, design strategies of skin structure for morphing wings require careful consideration of structural loading from shape changes and aerodynamics and their coupled effects in flight. Many morphing wings often overlook skin material and structure for the wing design. In addition to that, many works in the design of skins for morphing wings typically use smart materials, consider only geometric or static analysis but not dynamic deformation and strengths, or suggest a material condition and its properties that satisfy required structural and aerodynamic conditions. This work is focused on numerical analysis of structural and aerodynamic stress and strain of various lattice structures that will suggest desired design criteria of skin in camber morphing wings in the future. As a result, this paper shows numerical analysis of various lattice structures in accordance with camber moprhing and their potential effectiveness for skin of morphing wings.

Investigation on the feasibility of eliminating harmonic excitation signal en-route to performing experimental modal analysis (EMA) under operational condition

This study focuses on introducing a criteria for conducting harmonic excitation signal elimination as well as investigating its effectiveness towards achieving complete isolation of harmonic disturbance in performing EMA under operational condition. By modulating the ratio between harmonic excitation and impact knocking frequencies, it was revealed that the harmonic signal was efficiently attenuated with sufficient number of averaging blocks. The results highlighted close agreement between simulation and experimental approaches with maximum deviation of 2 %, under specific design criteria. It was determined that a non-periodic triggering frequency significantly affect the elimination performance in terms of trend and amplitude reduction. This work underlines the importance of controlling the triggering frequency to yield the desired design criteria for achieving rapid and highly efficient elimination of harmonic excitation signal. The results have proven that the proposed technique can be further adapted to isolate the harmonic in conventional EMA conducted under operational condition.

Design of PI Controller using Optimization Method in Fractional Order Control Systems

In control systems, controller preference and design is an important issue for meeting the desired design criteria. In this paper, PI controller design was performed by using optimization method for fractional order systems. First, all the PI controller parameters that make the control system stable are calculated by using the stability boundary locus method. However, each controller parameter selected in the stability region may not be able to optimally control the system. Optimal controller parameters that provide the best control from the PI controller parameters that make the system stable by using the optimization method are obtained. In the optimization process, the optimal PI controller parameters are calculated by using the integral performance criterion based on the error. Simulation studies have been done for closed loop control system including a fractional order transfer function with time delay. It has been shown that the presented method can be successfully applied to fractional order control systems.

PERANCANGAN KONFIGURASI STRUKTUR TOWER DAN PEMBUATAN BILAH KOMPOSIT (SANDWICH) UNTUK APLIKASI TURBIN ANGIN

Tower is a structure vertically designed that the blades and other components attached. The process for structural design for the tower starts by identifying all of the requirements, and then specifies the desired design criteria. The desired design criteria are high strength, low cost, lightweight, does not require a large area, ease of assembly and transport. The proposed tower types are guyed, lattice, and tubular. The analysis result shows that the lattice tower type matches with the design criteria. The next processes are modeling and stress analyzing using MSC Patran/Nastran. The maximum stress is 42 Newton per milimeters square and the Margin of safety (MS) value is 7.815, so the structure is safe. In the process of making the composite sandwich wind blades, it is starts with the creation of the master molding, mold, foam cores and assembly. The results of the three blades were made indicate by a difference in weight. It is caused by the manufacturing system (manual). However, the difference is still relevant or good because it is less than 5 percent.

Optimal control for reinitialization in finite element level set methods

SummaryA new optimal control problem that incorporates the residual of the Eikonal equation into its objective is presented. The formulation of the state equation is based on the level set transport equation but extended by an additional source term, correcting the solution so as to minimize the objective functional. The method enforces the constraint so that the interface cannot be displaced at least in the continuous setting. The system of first‐order optimality conditions is derived, linearized, and solved numerically. The control also prevents numerical instabilities, so that no additional stabilization techniques are required. This approach offers the flexibility to include other desired design criteria into the objective functional. The methodology is evaluated numerically in three different examples and compared with other PDE‐based reinitialization techniques. Copyright © 2016 John Wiley & Sons, Ltd.

Lattice design and beam dynamics studies for the PLS-II

Pohang Light Source (PLS) [1] had operated for 14 year successfully. To meet the request of the increasing user community, the PLS-II that is the upgrade project of PLS have been carried out. Main design goals of the PLS-II lattice are to increase beam energy to 3 GeV, to increase number of insertion devices by factor of two (20 IDs), to increase beam current to 400 mA and to reduce beam emittance below 10 nm with existing PLS tunnel and injection system. Following the desired design criteria, DBA lattice had been chosen such that the full storage ring includes 12 long straight sections and 12 short straight sections for installation of insertion devices with keeping beam emittance as small as possible. Through the six months of commissioning in the later half of 2011 and user operation in full period of 2012, we have successfully operated 14 insertion devices operation and top-up operation with 200 mA beam current and 5.8 nm beam emittance. It is especially important that good understanding of the machine operation and limitations can be achieved by comparison of experimental and simulation data during realizing final PLS-II goal and stable operation. Therefore, this paper describes the results of lattice design and beam dynamics studies for the PLS-II [2,3].

A spatially stratified, multi-stage cluster sampling design for assessing accuracy of the Alaska (USA) National Land Cover Database (NLCD)

Assessing the accuracy of a land-cover map is typically expensive, and at the planning stage it is often uncertain what final sample size will be affordable. The aim of this study is to develop an accuracy assessment sampling design that accommodates an ‘in progress’ change in target sample size without sacrificing other desirable design criteria. The sampling design constructed to assess the accuracy of the National Land Cover Database (NLCD) for Alaska achieves these desirable criteria. Spatial stratification provides the flexibility to accommodate a change in sample size and cluster sampling contributes to the cost-effectiveness of the design. We describe the advantages of these design features when the difficulty of accessing remote, large areas is a primary driver of the choice of a sampling design for accuracy assessment. Estimators for overall, user's, and producer's accuracies along with approximate standard errors are provided for the stratified, multi-stage cluster sampling design proposed.

Sampling designs for accuracy assessment of land cover

The accuracy of a land cover classification is the degree to which the map land cover agrees with the reference land cover classification (i.e. ground condition). The basic sampling designs historically implemented for map accuracy assessment have served well for the error matrix based analyses traditionally used. But contemporary applications of land cover maps place greater demands on accuracy assessment, and sampling designs must be constructed to target objectives such as accuracy of land cover composition and landscape pattern. Sampling designs differ in their suitability to achieve different objectives, and trade-offs among desirable sampling design criteria must be recognized and accommodated when selecting a design. An overview is presented of the sampling designs used in accuracy assessment, and the status of these designs is appraised for meeting current needs. Sampling design features that facilitate multiple-objective accuracy assessments are described.

Thermochemical Ablation: A Novel Technique for Solid Tumor Therapy

To overcome the limitations of existing ablation techniques, we propose a novel combinatorial approach that would utilize the thermal and chemical destructive effects of exothermic chemical reactions, such as an acid/base neutralization reaction, to treat solid tumors. Thermochemical ablation is a potential technique for percutaneous probe-based tumor therapy. It involves simultaneous intratumoral delivery of multiple reagents resulting in thermal energy released by an exothermic reaction to ablate tumor tissue with concurrent generation of a hyperosmolar byproduct that could accentuate tumor destruction. Besides the benefit of synergistic thermal and chemical effects for tumor tissue destruction, this technique is potentially highly cost-effective, easy to implement, and able to treat larger sized tumors. Our hypothesis is that thermochemical ablation can create an evenly distributed zone of coagulation in tumor tissue without systemic toxicity. A prototype device assembled using off-the-shelf components is being investigated in our lab for concurrent intraparenchymal delivery of an acid and a base. The distal portion of the multi-lumen device allows for passive mixing of the reagents before entering the tissue. The prototype device also satisfies other desirable design criteria such as rigidity to penetrate body tissue, reduced diameter, chemical stability to reagents, etc. However, the device can be improved upon by incorporating additional characteristics such as optimized imaging characteristic for real-time visualization and localization within tumor tissue, MRI compatibility, thermal insulation, improved mixing at the tip, etc. Our lab is currently working on improving the design of the infusion device as well as assessing the feasibility of the thermochemical ablation technique in vitro and in vivo. While currently being targeted conservatively for palliative therapy of unresectable or late-stage aggressive malignancies such as hepatocellular carcinoma, thermochemical ablation has potential use in the therapy of a majority of solid tumors such as breast cancer, lung cancer, prostate cancer, renal cancer, sarcomas, etc.

Green Tick™: an example of sustainability certification of goods and services

PurposeThe purpose of this paper is to describe a sustainability certification system and label based on an independent, full life cycle assessment of conventionally produced goods from “cradle to grave”.Design/methodology/approachThe design approach used comprised five phases: review of presently available third party environmental certification systems regarding their suitability for use as a sustainability certification tool for conventionally produced goods; identification of desirable scientific and consumer design criteria for a sustainability certification system and label; identification of key performance indicators for sustainability; description of an independent sustainability certification system based on the desirable design criteria, in particular an independent full life cycle assessment; and market trials of the sustainability label to test consumer reactions and commercial benefits of independent sustainability certification using two commercial case studies in Australia and New Zealand.FindingsNone of the third party environmental certification systems reviewed was suitable for use as a sustainability certification tool. Desirable design criteria for a sustainability certification system centred on an independent, full life cycle assessment of operations from “cradle to grave”. A total of eight safety and 12 sustainability key performance indicators were proposed to specifically assess sustainability performance. An instantly recognizable logo comprising a “Green Tick” inside a circle, reminiscent of a government “stamp of approval”, was used as a sustainability label. Market trials of certified household products and lamb meat in Australasia confirmed positive consumer reactions to the “Green Tick” label, and considerable commercial benefits for the companies that used it on their products.Practical implicationsThe “Green Tick™” sustainability certification system and label addresses an identified gap in the market by providing an easily recognizable, independent, life cycle based sustainability certification of consumer products. Market trials indicated that there was measurable consumer support for independent sustainability labelling, and significant commercial benefits for companies whose products qualified for sustainability labelling.Originality/valueThe paper describes the world's first‐ever independent sustainability certification system and label. It is based on third party, full life cycle assessment of products, in accordance with the European Commission's view that sustainability labelling should be based on independent, full life cycle assessments of products. Market trials of the label in the Australasian FMCG sector indicated that consumers responded positively to an easily recognizable, independent sustainability label, and that independent sustainability certification and labelling have significant commercial potential for manufacturers of genuinely sustainable products.

New Method for Design of Flat Steel Ribbon-Wound Pressure Vessels

It has been observed that the degree of contact between layers and the residual stresses caused by pre-tension winding of ribbons does not influence bursting pressure of flat steel ribbon-wound pressure vessels. This suggests the idea that the desirable design criteria for vessels of this type should be based on bursting failure mode, i.e., wall thickness should be determined by bursting pressure which is strongly influenced by friction between layers and laminar effects. It is shown that the probability of bursting failure of vessel for which the bursting pressure is not less than 2.5 design pressure is less than 10−10. An example demonstrates that a design procedure based on this information not only has significant economic advantages, but also can indicate bursting probability.

Thin silicide development for fully-depleted SOI CMOS technology

Ultrathin silicide with thickness less than 30 nm and specific contact resistivity to silicon less than mid-10/sup -7//spl Omega/-cm/sup 2/ is necessary for achieving low contact resistance in a sub-0.25-/spl mu/m fully-depleted (FD) silicon-on-insulator (SOI) CMOS technology. This contact problem becomes even more severe as one continues to scale down the device dimensions. We first studied the effects of source/drain series resistance and gate sheet resistance on the device speed performance and obtained a set of desired design criteria. These were used along with a transmission line model to yield a silicide design space, which was then used to evaluate the experimental results. Both cobalt and titanium silicide processes were implemented and found to satisfy the design criteria. Final device characteristics were also measured. Several process integration issues related to contact dielectric deposition and contact barrier integrity were found to greatly impact the final contact properties. These along with the detailed fabrication process are discussed.

Book reviews

There are three aspects of quality assurance programmes — acceptance testing against specified tolerances, routine testing and treating against established baseline results and desirable design criteria for performance. There is always a considerable degree of overlap and the same methods of testing often apply. For instance, published “state of the art” parameters enable us to specify a minimum level of performance and the acceptance testing against that standard can be taken as the baseline for the routine quality assurance tests and the day-to-day checking that is so important.

Development of a Chili Pepper Harvester

ABSTRACT:A chili pepper harvester using the spring-tine picking principle has been designed, constructed and field tested. Chili peppers are collected in moving buckets and elevated to a cleaning and sorting belt which moves the chilies to the transport vehicle. Both red and green chilies can be harvested. Desirable design criteria for a successful chili pepper harvester are presented.