bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimization of a truck-drone in tandem delivery network using k-means and genetic algorithm
Authors: Mourelo Ferrandez Sergio , Harbison Timothy , Weber Troy , Sturges Robert , Rich Robert 
Published: April 2016

Purpose: The purpose of this paper is to investigate the effectiveness of implementing unmanned aerial delivery vehicles in delivery networks. We investigate the notion of the reduced overall delivery time, energy, and costs for a truck-drone network by comparing the in-tandem system with a stand-alone delivery effort. The objectives are (1) to investigate the time, energy, and costs associated to a truck-drone delivery network compared to standalone truck or drone, (2) to propose an optimization algorithm that determines the optimal number of launch sites and locations given delivery requirements, and drones per truck, (3) to develop mathematical formulations for closed form estimations for the optimal number of launch locations, optimal total time, as well as the associated cost for the system.Design/methodology/approach: The design of the algorithm herein computes the minimal time of delivery utilizing K-means clustering to find launch locations, as well as a genetic algorithm to solve the truck route as a traveling salesmen problem (TSP). The optimal solution is determined by finding the minimum cost associated to the parabolic convex cost function. The optimal min-cost is determined by finding the most efficient launch locations using K-means algorithms to determine launch locations and a genetic algorithm to determine truck route between those launch locations. Findings: Results show improvements with in-tandem delivery efforts as opposed to standalone systems. Further, multiple drones per truck are more optimal and contribute to savings in both energy and time. For this, we sampled various initialization variables to derive closed form mathematical solutions for the problem. Originality/value: Ultimately, this provides the necessary analysis of an integrated truck-drone delivery system which could be implemented by a company in order to maximize deliveries while minimizing time and energy. Closed-form mathematical solutions can be used as close estimators for final costs and time.
Cost Breakdown of 2.5D and 3D Packaging
Authors: Palesko Chet , Palesko Amy 
Published: April 2016

2.5D and 3D packaging can provide significant size and performance advantages over other packaging technologies. However, these advantages usually come at a high price. Since 2.5D and 3D packaging costs are significant, today they are only used if no other option can meet the product requirements, and most of these applications are relatively low volume. Products such as high end FPGAs, high performance GPUs, and high bandwidth memory are great applications but none have volume requirements close to mobile phones or tablets. Without the benefit of volume production, the cost of 2.5D and 3D packaging could stay high for a long time.
In this paper, we will provide cost model results of a complete 2.5D and 3D manufacturing process. Each manufacturing activity will be included and the key cost drivers will be analyzed regarding future cost reductions. Expensive activities that are well down the learning curve (RDL creation, CMP, etc.) will probably not change much in the future. However, expensive activities that are new to this process (DRIE, temporary bond/debond, etc.) provide good opportunities for cost reduction. A variety of scenarios will be included to understand how design characteristics impact the cost. Understanding how and why the dominant cost components will change over time is critical to accurately predicting the future cost of 2.5D and 3D packaging.
Laser-based Package Singulation and Trenching for SiP
Authors: Mueller Dirk , Clark David , VanNunen Joris , Rea Ed , Haloui Hatim 
Published: April 2016

Pulsed lasers are solving some packaging challenges for SiP applications. SiP devices designed for mobile devices with communication capability often have a need for EMI shielding. Nanosecond UV and picosecond green lasers are finding use in cutting these multi-compound packages as well as trench for exposing board contacts used for grounding. Mechanical cutting may not be an option if the perimeter of the package is not a simple rectangle. Water jet cutting may bear the risk of the package to fail to to water seeping in between the package layers during cutting. We will demonstrate how laser-based SiP package cutting and trenching can ameliorate both of those concerns and point toward limitations of laser-based processes.
Today's high power nanosecond UV lasers are capable of cutting 1mm thick packages at an effective cutting speed of more than 10mm/s. The resulting cut surface shows no charring or melting. The surface roughness allows for excellent adhesion of EMI shielding paint on the cut conformal compound. Since the laser beam can be controlled with a programmable scanner, arbitrary shapes can be cut just as easily as simple rectangles.
Difference ablation rates between polymer and copper allow the laser to trench the conformal coating and stop automatically when a metal layer is exposed. This self-terminating process leads to a precise exposure even when the conformal coating thickness differs from part to part.
For the utmost in surface quality picosecond lasers can be employed. Their shorter pulse duration allows for an even lower surface roughness and less thermal impact on the package. Using an ultrafast laser, such as a 10ps laser, has the additional advantage that the process scales in speed with increased laser power.
The excellent edge quality and possibility to cut random shapes allow laser-based processes to complement mechanical processes in high-end applications. We will present a full cost of ownership model that allows the designer to predict the exact singulation and trenching cost for a given package size.
A study on warpage behavior of EMC in post-mold cure stage using Moldex3D
Authors: Chih-Chung Hsu , Vallury Srikar , Vallury Srikar , Lin Kai , Yang Anthony 
Published: April 2016

Warpage and residual stress are the two most important factors affecting product yield rate and reliability in IC encapsulation process. This study presents the prediction of warpage in post-mold cure stage using a three-dimensional finite element approach coupled with linear viscoelastic material property. Furthermore, cure-induced volumetric shrinkage and thermal expansion mismatch are considered. The shrinkage of the EMC is described by Pressure-Volume-Temperature-Cure (PVTC) model, and Generalized Maxwell model; WLF relation is adopted to describe the viscoelastic behavior of EMC.
In order to obtain accurate numerical results, Cure-Time-Temperature superposition is considered. For verifying the numerical predictions of three dimensional simulations, the calculated results are compared with the available experimental data from literature.
A MEMS PPA Based Active Vibration Isolator - STUDENT AWARD 3RD PLACE $500
Authors: Li Chong , Elana C. Lavinia , Dean Robert N. , Flowers George T. 
Published: April 2016

Several types of micro-devices are adversely affected by high frequency mechanical vibrations present in the operating environment. Examples include MEMS vibratory gyroscopes and resonators, and micro-optics. Various types of MEMS vibration isolators have been developed for use in the packaging of these vibration sensitive devices. Passive isolators consist of a spring-mass-damper MEMS device and usually have a very high mechanical quality factor, which makes them susceptible to ringing at the isolator's resonant frequency. Active isolators have been realized by using state sensing of the proof mass motion and feeding one or more of these states back through an actuator to adjust the frequency response of the isolator. For example, the technique known as skyhook damping uses velocity feedback to adjust, and typically increase, the damping of the isolator. Although these technique are doable, they require state sensing or state estimation, with feedback electronics to drive the actuator.
A simpler MEMS active vibration isolator architecture employs only a parallel plate actuator (PPA) with the MEMS spring-mass-damper structure. The PPA driven with a DC voltage, in its stable operating range, displaces the proof mass, which results in a change in the effective system spring constant due to the electrostatic spring softening effect. This results in a change in the resonant frequency and the quality factor of the isolator. However, due to the nonlinearities inherent in this type of device, the stable operating range is reduced as the PPA voltage is increased. Furthermore, even when the isolator is stable in steady-state, a sufficiently large transient response can also drive it into the unstable regime, resulting in the electrodes snapping into contact.
In this study, the PPA based active vibrator isolator is developed and its performance is evaluated. The characteristics of the transient instability are investigated and its stable range of operation is specified, for booth external disturbances and rapid application of the control voltage. This MEMS PPA based active vibration isolator can improve performance compared to passive isolators, while being much simpler than state feedback active isolators.
Emerging Flux Challenges for BGA Packages
Authors: Durham Maria , Mackie Andy , Chou Jason 
Published: April 2016

The formation of a Ball Grid Array (BGA) solder joint is critical for a BGA package where typically a flux deposition process is used. Reflowing solder spheres to solderable pads on the bottom of substrates in standard BGA, FCBGA, CSP, and similar packages is considered to be a trivial step: a specialized BGA flux is usually pin-transferred onto the pads, followed by balldrop onto the substrate. However, with the increasing complexity and number of assembly processes taken prior to this final step, the formation of a reliable final joint is far from certain. In order to eliminate variability, many OSATs and ODMs use the so-called “two step” (double fluxing) approach, which is comprised of the non-value-added extra processes of prefluxing, reflowing, cleaning, and drying substrates immediately prior to the final flux-based ball-attach process.
This paper details the sequence of processes seen in typical FCBGA assembly, and examines the effects of each set of prior processes on the solderability of the final pad. The introduction of a “one-step” pin-transfer ball-attach flux is shown to be a means of reducing both process cost and time, and also reducing the risk of increased warpage in the finished package.
The paper also investigates the solderable surface and metallurgy of the substrate pad. The variety of new and emerging failure modes for the BGA process as well as the different testing methods for the materials will also be discussed.
A Matched Filter Developed for Chaotic Waveforms
Authors: Werner Frank T. , Rhea Benjamin K. , Beal Aubrey N. , Abell William E. , Bailey John P. , Harrison Remington C. , Dean Robert N. , Hamilton Michael C. 
Published: April 2016

A matched filter developed for use in chaos-based communications systems is presented. A matched filter is the optimum filter for maximizing the signal-to-noise ratio of a received signal in the presence of additive Gaussian white noise (AGWN). Chaos-based communications systems encode information into a chaotic waveform using arbitrary small perturbations to control the trajectory of the chaotic oscillator. Chaotic waveforms are deterministic, are sensitive to initial conditions, have aperiodic long-term behavior, have a spread frequency spectrum, and are theoretically immune to interference. There has been great interest in using chaotic waveforms in communication applications. One reason for this interest is that the spread spectrum of a chaotic waveform gives the appearance of noise when observed over a prolonged period of time. This masks the waveform from anyone without prior knowledge of its presence. Another reason is that to retrieve the information encoded in the chaotic waveform, complete knowledge of the waveform must be known. This makes it difficult for anyone other than the intended recipient to decrypt the information.
Normally, implementing a matched filter for a chaotic waveform is difficult because such waveforms do not have a fixed basis function and have irregular timing. However, a unique chaotic oscillator has been developed that can be represented as an exact analytic solution. The waveform's solution can be written as a convolution of a symbol sequence and a fixed basis function. This fixed basis function makes it possible to derive a delay differential equation describing the matched filter.
In order to test the matched filter, an amplitude modulated communications system was developed. In the system, the oscillator's output is first amplitude modulated with 2.3GHz carrier before being transmitted. The receiver then demodulates the signal and applies it to the matched filter. Any encoded information can then be extracted from the output of the matched filter. The oscillator and matched filter were designed to operate at 1.8MHz. In both simulation and testing, the matched filter was able to detect the chaotic waveform in the presence of AWGN.
Innovated L/S less than 2/2μm Line Embedded 2.1D Organic Substrate Technology
Authors: Chen Yu-Hua 
Published: April 2016

Current organic substrates are limited to lines/space of 10/10um and via size around 50um. However, the semiconductor with advance node needs fine line/space of 5/5 or 3/3 and even 2/2μm in the future. Si Interposer provides a high density interconnection with fine line and small via that cannot be matched by current laminate substrate technology. But the challenge of Si interposer is the high cost. We have developed an ultra-thin line embedded substrate for 2.1D/2.5D SiP application.
There are two types of approach to meet the requirement of line/space less than 2/2μm in the organic substrate. One is the conventional Semi-Additive Process (SAP) and another is laser embedded technology. The advantage of SAP is the good compatibility with current process but the problem is yield and reliability issue for narrow copper trace on the dielectric surface. From the current status, line/space of 5/5μm will be the process limitation of SAP and 2/2μm need to be further verified for HVM.
Another solution is line embedded (LE) technology with the different structure. LE technology is different from SAP includes ablation of trench by laser and panel plating with electroplating copper and then removing copper above dielectric surface for formation of Cu pattern. There are several advantages of laser embedded comparing to SAP. First, the laser embedded substrate provides a flat surface after formation of pattern which is helpful for covering a thinner solder mask with better uniformity of thickness. It can avoid the voids formation while filling molding compound. Second, the laser embedded substrate not only allows the design of pad-less via to reduce both package size and format but also can put more traces near these vias.
In this study, several key technologies of laser embedded are successfully integrated in the current substrate process. By the selection of the advanced dielectric film with a suitable design as a test vehicle to verify the feasibility of laser embedded technology with line/space of 5/5μm and 3/3μm design. However, the excimer laser ablated the pattern step-by-step and the throughput was much lower than lithography by exposure. The technology trend shows that the use of non-filler photo-sensitive dielectric (PID) by exposure/development to form trenches of signal paths is a good solution to increase throughput. L/S less than 2/2μm line embedded 2.1D organic substrate achievement by adopting innovated integration PID process will be further discussed.
Evaluation of low back pain with low field open magnetic resonance imaging scanner in rural hospital of Southern India
Authors: Shrinuvasan Sadhanandham , Chidambaram Ranganathan 
Published: April 2016

ABSTRACTBackground: Low back pain (LBP) is the most common symptom which is associated with limitation of normal activities and work-related disability. Imaging techniques are often essential in making the correct diagnosis for prompt management. Plain Radiography though remain a first imaging modality, magnetic resonance imaging (MRI) due to its inherent softtissue contrast resolution and lack of ionizing radiation remains invaluable modality in the evaluation of LBP. Aim: To find the common causes of LBP in different age groups and the role of MRI in detecting the spectrum of various pathological findings. Materials and Methods: This is a prospective study done in the Department of Radiodiagnosis during a period of 2 years from July 2013 to July 2015. The study population includes all the cases referred to our department with complaints of LBP. Patients with ferromagnetic metallic implants and uncooperative cases were excluded. HITACHI 0.4 Tesla open MRI machine was used for imaging. Results and Conclusion: This study involved a total of 235 cases. There were 121 males and 114 females. The age of the patient ranged from 21 to 68 years with an average of 41.3 years. Back pain was commonly observed in the third to fifth decade. The common causes for back pain are disc herniations (disc bulge - 35.3%, disc protrusion - 39.6%, disc extrusion - 7.2%) accounting to 82.1%, followed by normal study (10.2%), vertebral collapse (traumatic - 2.1%, osteoporotic - 1.7%), infections (2.1%), and neoplasm (1.7%). MRI provides valuable information regarding the underlying causes of LBP, especially in disc and marrow pathology.
Reviewer Acknowledgements for International Journal of Chemistry, Vol. 8, No. 2
Authors: John Albert 
Published: April 2016

International Journal of Chemistry wishes to acknowledge the following individuals for their assistance with peer review of manuscripts for this issue. Their help and contributions in maintaining the quality of the journal is greatly appreciated.Many authors, regardless of whether International Journal of Chemistry publishes their work, appreciate the helpful feedback provided by the reviewers. Reviewers for Volume 8, Number 2 Adel F. ShoukryAjeet KumarAmer A. TaqaChanchal Kumar MalikDiego AlonsoGreg PetersHarsha D. MagurudeniyaHesham G. IbrahimJalal IsaadK. Ishara SilvaKallen Mulilo NalyanyaKhandan AmirsalarMadduri SrinivasaraoMeriem BelhachemiMohamed AbassMustafa Oguzhan KayaNanda GunawardhanaNejib Hussein MekniPrathapan SreedharanPraveen KumarQun YeR. K. DeyRabia RehmanRuogu PengSeverine QueyroySitaram AcharyaVahid HejaziVijay RamalingamXianlong Wang Albert JohnOn behalf of,The Editorial Board of International Journal of ChemistryCanadian Center of Science and Education
Precision Medicine in Gastrointestinal Pathology
Authors: Wang David H. , Park Jason Y. 
Published: April 2016

Context.—Precision medicine is the promise of individualized therapy and management of patients based on their personal biology. There are now multiple global initiatives to perform whole-genome sequencing on millions of individuals. In the United States, an early program was the Million Veteran Program, and a more recent proposal in 2015 by the president of the United States is the Precision Medicine Initiative. To implement precision medicine in routine oncology care, genetic variants present in tumors need to be matched with effective clinical therapeutics. When we focus on the current state of precision medicine for gastrointestinal malignancies, it becomes apparent that there is a mixed history of success and failure.
Objective.—To present the current state of precision medicine using gastrointestinal oncology as a model. We will present currently available targeted therapeutics, promising new findings in clinical genomic oncology, remaining quality issues in genomic testing, and emerging oncology clinical trial designs.
Data Sources.—Review of the literature including clinical genomic studies on gastrointestinal malignancies, clinical oncology trials on therapeutics targeted to molecular alterations, and emerging clinical oncology study designs.
Conclusions.—Translating our ability to sequence thousands of genes into meaningful improvements in patient survival will be the challenge for the next decade.
Space‐based imaging of nighttime medium‐scale traveling ionospheric disturbances using FORMOSAT‐2/ISUAL 630.0 nm airglow observations
Authors: Rajesh P. K. , Liu J. Y. , Lin C. H. , Chen A. B. , Hsu R. R. , Chen C. H. , Huba J. D. 
Published: April 2016

AbstractThis paper reports the results of space‐based imaging of nighttime medium‐scale traveling ionospheric disturbances (MSTIDs) in 630.0 nm emission by Imager of Sprites and Upper Atmospheric Lightnings (ISUAL), on board FORMOSAT‐2 satellite. The limb integrated measurements, after removing background, reveal multiple bands of intensity perturbation when projected to a horizontal plane corresponding to the altitude of peak emission, with distinct southwest to northeast orientation in the Southern Hemisphere. Simulations are carried out by artificially introducing MSTID fluctuations in model electron density to confirm if the MSTID could be identified in the ISUAL‐viewing geometry. The ISUAL observations in year 2007 are further used to investigate the MSTID features as well as occurrence characteristics in the Southern Hemisphere, most of which are over the ocean where no ground‐based observations are available. The preliminary statistics shows more MSTID occurrence in solstices with peak in June–July months. Majority of the MSTID perturbations have wavelength in the range 150–300 km, and the wavefronts are aligned at about 30°–50° from the east‐west plane. The statistic results of the orientation of wavefronts indicate that Es layer instability might be important in the MSTID generation.
Fast dropouts of multi‐MeV electrons due to combined effects of EMIC and whistler mode waves
Authors: Mourenas D. , Artemyev A. V. , Ma Q. , Agapitov O. V. , Li W. 
Published: April 2016

AbstractWe investigate how whole populations of 2–6 MeV electrons can be quickly lost from the Earth's outer radiation belt at L= 3–6 through precipitation into the atmosphere due to quasi‐linear pitch angle scattering by combined electromagnetic ion cyclotron (EMIC) and whistler mode waves of realistic intensities occurring at the same or different local times. We provide analytical estimates of the corresponding relativistic electron lifetimes, emphasizing that the combined effects of both waves can lead to very fast (2–10 h) dropouts. Scaling laws for the loss timescales are derived, allowing us to determine the various plasma and wave parameter domains potentially leading to strong and fast dropouts. The analysis reveals that the fastest MeV electron dropouts occur at approximately the same rate over some high energy range and almost independently of EMIC wave amplitudes above a certain threshold. These results should help to better understand the dynamic variability of the radiation belts.