A Hybrid Synthetic Aperture and Time-Reversal MUSIC Algorithm for Subwavelength Radar Imaging

A promising chipless RFID approach uses millimeter-wave synthetic aperture radar (SAR) to image metal ink-printed ID tags from a meter or more away. Due to printing cost, it is desirable to minimize the size and spacing of metal patches within a tag, preferably into the subwavelength regime. Although circular SAR (CSAR) has a sharply peaked point response in 2D, its side lobes of closely-spaced targets interfere strongly with each other to distort the image. An alternative 2D subwavelength imaging approach with minimal side lobes is Time-Reversal MUSIC (TR-MUSIC). Traditional TR-MUSIC, however, requires a large number of transmitters and receivers. We propose a hybrid synthetic aperture TR-MUSIC algorithm (SATR-MUSIC) that combines the benefits of both approaches. Using relatively few transceivers, SATR-MUSIC is able to resolve objects separated by approximately in 2D with minimal background artifacts. It does so by averaging TR-MUSIC’s imaging kernel incoherently over the synthetic aperture.

Controlled Release of Bi-Layered Malvidin Tablets Using 3D Printing Techniques

Malvidin belongs to the class of anthocyanidin, a pigment compound present in fruits and vegetables like the colored berries, flowers, and vegetables which have pigments on it and it is available commercially as malvidin chloride. Malvidin is known to possess many medicinal characteristics like anti-microbial, anti-diabetic, anti-inflammatory, anti-obesity, and anti-cancer. In this research paper, a 3D printing technique is used which evolves a 3D printer based on desktop that extrudes tablets comprising the active drug which here is malvidin our main ingredient and the other excipients which are used as binders and disintegrants. Methods which are adapted here for the formulation of 3D printed tablet make the tablets appropriate for immediate and sustained release with its definite physical and mechanical properties like hardness, friability, and weight. Tablets that are extruded by the 3D printer are controlled release bi-layer tablets. Due to involvement of 3D printer, printing cost for the bi-layered tablets found very low that makes our method as cost efficient.

Build Orientation Optimization Based on Weighted Analysis of Local Surface Region Curvature

Build orientation becomes a hot issue in 3D printing, which has a significant impact on the surface quality, support structure and final cost of the fabricated model. In this paper, we focus our attention on the surface quality of the part when fabricated by a 3D printer under certain specific build orientation. A novel method using curvature shift is proposed to search local regions with obvious curvature changes of the model printed. Based on curvature shift strategy, the model is divided into separate regions which can be treated differently. Every triangle facet of the regions is given different weight factor by calculating the average curvature of each region. Weighted facets is introduced in building volume error function. Candidate build orientation can be obtained by the eigenvalue decomposition and the optimal build orientation is the one which leads to the minimal error of the function. From the case study, the method proposed gets a smaller error with a lower printing cost and time, which means the model surface in higher weighted regions gets a higher surface quality when printed.

Evaluation of 3D printing costs in surgery: a systematic review

ObjectivesThe use of three-dimensional (3D) printing in surgery is expanding and there is a focus on comprehensively evaluating the clinical impact of this technology. However, although additional costs are one of the main limitations to its use, little is known about its economic impact. The purpose of this systematic review is to identify the costs associated with its use and highlight the first quantitative data available.MethodsA systematic literature review was conducted in the PubMed and Embase databases and in the National Health Service Economic Evaluation Database (NHS EED) at the University of York. Studies that reported an assessment of the costs associated with the use of 3D printing for surgical application and published between 2009 and 2019, in English or French, were included.ResultsNine studies were included in our review. Nine types of costs were identified, the three main ones being printing material costs (n = 6), staff costs (n = 3), and operating room costs (n = 3). The printing cost ranged from less than U.S. dollars (USD) 1 to USD 146 (in USD 2019 values) depending on the criteria used to calculate this cost. Three studies evaluated the potential savings generated by the use of 3D printing technology in surgery, based on operating time reduction.ConclusionThis literature review highlights the lack of reliable economic data on 3D printing technology. Nevertheless, this review makes it possible to identify expenditures or items that should be considered in order to carry out more robust studies.

PENYELENGGARAAN UJIAN SEKOLAH BERSTANDAR NASIONAL JENJANG PENDIDIKAN MENENGAH

AbstrakTujuan penelitian ini adalah mengkaji penyelenggaraan USBN jenjang pendidikan menengah yang meliputi persiapan, pelaksanaan, paska pelaksanaan, dan penyiapan peningkatan kompetensi guru dalam penyusunan soal USBN. Penelitian ini menggunakan pendekatan kualitatif, dengan teknik pengumpulan data melalui diskusi kelompok terpumpun. Penelitian ini dilakukan di tiga daerah, yakni Provinsi Banten, Provinsi Nusa Tenggara Barat, dan Provinsi Maluku Utara. Hasil penelitian menyebutkan bahwa pada tahap persiapan USBN berjalan lancar namun terdapat kendala pada saat pendistribusian, penggandaan, dan pembiayaan percetakan naskah soal. Pelaksanaan USBN berjalan lancar dan sesuai dengan jadwal yang telah ditentukan, naskah soal disusun dan dirakit oleh dinas pendidikan. Pada paska pelaksanaan satuan pendidikan melakukan pengoreksian menggunakan scanner atau manual. Tidak semua satuan pendidikan memberikan hasil pengoreksian USBN kepada dinas pendidikan, sehingga pihak dinas pendidikan merasa kesulitan untuk memetakan mutu pendidikan berdasarkan hasil USBN tersebut. Selain itu, penyusunan soal USBN jenjang pendidikan menengah yang dilakukan oleh guru-guru yang terhimpun dalam MGMP belum memiliki kualitas yang memadai. Simpulan penelitiannya adalah bahwa penyelenggaraan USBN tahun 2017 secara umum berjalan lancar, walaupun masih terdapat beberapa kendala. AbstractThe management of school exam based on national standar (SENS) at upper secondary education level which includes preparation, implementation, post-implementation, and preparing teacher competency improvement in the compilation of SENS questions. This study uses a qualitative approach, with the technique of collecting data used is a focus group discussion. This research is done in three provinces is.c.q. Banten, West Nusa Tenggara, and North Maluku. This research results is the preparation phase of SENS was running smoothly but there are is constrained on the time of distribution, printing, and printing cost. Implementation of SENS was running smoothly and on schedule,questions compiled and assembled by education office. At post implementation, schools correction of SENS using scaners or manually. Not all schools give SENS correction results to the education office, so it feels the difficulty to map the quality of education based on SENS results. Besides that, the compilation of SENS questions at the secondary education level carried out by teachers namely discussion of subject teacher have not yet adequate quality. The conclusion is that implementation of 2017 SENS was running smoothly, eventhough there are some constraints.

Cellulose nanocrystals (CNC) reinforced shape memory polyurethane ribbons for future biomedical applications and design

Shape memory materials are an innovative type of materials that reversibly store a temporary shape and recover back to the original dimensions with the application of an external mechanism such as heat. Shape memory polymers (SMP), specifically thermoplastic SMP (e.g. shape memory polyurethane (SMPU)) have received much attention during the past decade because of the promising future applications and advantages such as ease of processability for thermoplastic SMP (e.g. by 3-D printing), cost, and biocompatibility. In the biomedical field, applications such as stents, surgical sutures, and orthodontic devices, amongst others have been proposed. The addition of fillers to the material can modify the material to improve their load bearing capabilities. Bio-based fillers such as cellulose nanocrystals (CNC) have been proposed in a variety of reinforcing applications. The present work focuses on the experimental description of the addition of nonmodified CNC to SMPU. The work studied the effect on melt-extruded ribbons, for 0, 0.5, 1, 2, and 4 wt%. An increase of yield point, toughness, flexural modulus, recovery rate, and decrease of total time showed that SMPU/CNC nanocomposites are a potential candidate to use in future biomedical applications.

A Hybrid Simulated Annealing/Linear Programming Approach for the Cover Printing Problem

TheNP-hard cover printing problem addressed here consists in determining the number and composition of equal size impression grids, as well as the number of times each grid is printed, in order to fulfill the demand of different book covers at minimum total printing cost. The considered costs come from printing sheets and for composing grids. Thus, to deal with this combinatorial optimization problem we investigated two heuristics: one combines simulated annealing and linear programming techniques and the other is a hybrid of Tabu Search and an ad hoc procedure. Through intensive testing on available instances, these algorithms proved to be superior to previous approaches.

E-Learning Tutoring System for Sijil Pelajaran Malaysia (SPM) English

An E-Learning tutoring system for English (SPM) is an e-learning platform for Sijil Pelajaran Malaysia English subject. E-learning is a web based application that supports the delivery of learning, skills and knowledge related to the English subject in SPM. E-learning use the technology to enable people to learn anytime and anywhere. Besides, it is developed with the purpose to evaluate student’s performance through an online quiz. Nowadays, tuition center have a lot of students, hence insufficient time to analyze the individual performance in learning English. In addition, e-learning is able to reduce the printing cost and administrative cost at the same time reducing usage of paper and printed materials associate in learning. The system developed by using Javascript and PHP language based on system prototyping methodology. The result will produce student’s performance in monthly quiz and teacher are able to monitor the performance of each students. Although the development or this e-learning is based on requirement gathered via tuition center, however it can be proposed to be by any learning center or to self-study. It is hoped that this e-learning will be able to improve student knowledge in English language and subsequently help student to obtain the best result in SPM by providing more guided references and practices.