Redefining A in RGBA: Towards a Standard for Graphical 3D Printing

Advances in multimaterial 3D printing have the potential to reproduce various visual appearance attributes of an object in addition to its shape. Since many existing 3D file formats encode color and translucency by RGBA textures mapped to 3D shapes, RGBA information is particularly important for practical applications. In contrast to color (encoded by RGB), which is specified by the object's reflectance, selected viewing conditions and a standard observer, translucency (encoded by A) is neither linked to any measurable physical nor perceptual quantity. Thus, reproducing translucency encoded by A is open for interpretation. In this paper, we propose a rigorous definition for A suitable for use in graphical 3D printing, which is independent of the 3D printing hardware and software, and which links both optical material properties and perceptual uniformity for human observers. By deriving our definition from the absorption and scattering coefficients of virtual homogeneous reference materials with an isotropic phase function, we achieve two important properties. First, a simple adjustment of A is possible, which preserves the translucency appearance if an object is re-scaled for printing. Second, determining the value of A for a real (potentially non-homogeneous) material, can be achieved by minimizing a distance function between light transport measurements of this material and simulated measurements of the reference materials. Such measurements can be conducted by commercial spectrophotometers used in graphic arts. Finally, we conduct visual experiments employing the method of constant stimuli, and derive from them an embedding of A into a nearly perceptually uniform scale of translucency for the reference materials.Comment: 20 pages (incl. appendices), 20 figures. Version with higher quality images: https://cloud-ext.igd.fraunhofer.de/s/pAMH67XjstaNcrF (main article) and https://cloud-ext.igd.fraunhofer.de/s/4rR5bH3FMfNsS5q (appendix). Supplemental material including code: https://cloud-ext.igd.fraunhofer.de/s/9BrZaj5Uh5d0cOU/downloa

Adolescent ovarian tumours: a gynecologist’s dilemma

Background: Objective: To review the clinical presentation and outcome of ovarian tumours in children and adolescents upto 20 years of age, who presented at K. J. Somaiya Hospital and Medical research centre.Methods: The study was carried out in the Ob/Gyn department at K. J. Somaiya Hospital and Medical research centre between 2006 and 2012 after approval from the ethical committee. The data of the patients regarding age, presentation, diagnosis, investigations, treatment, and outcome was reviewed and analysed.Results: There were 32 patients between 13 and 20 years of age who presented with an ovarian tumour during the study period. Majority of the patients belonged to age group 17-19 years. The main presenting symptom was pain in abdomen in 21 (65%) patients. Operative procedures included 18 (56%) exploratory laparotomies and 14 (44%) operative laparoscopies. Ovarian cystectomy was done in 23 (71%) patients, unilateral oophorectomy in 3 (9%) patients, bilateral oophorectomy with omentectomy in 1 (3%) patient and salpingoophorectomy in 1 (3%) patient. Histopathology reports showed 2 cases each of serous cystadenoma, mucinous cystadenoma and dermoid cyst and one case of dysgerminoma. Corpus lutueal cyst was most common cyst found on histopathology.  Conclusions: Early correct diagnosis of ovarian masses in young girls is important and can be reached by careful physical examination, imaging and tumour markers. Surgery should be as much as possible for fertility preservation. The treatment of malignant tumors would involve complete staging, resection of the tumor, postoperative chemotherapy when indicated, to give the patient a chance for future childbearing.

Integrated foodbank network design: Model and a case study

To address the UN’s zero hunger goal (SDG 2), scattered and isolated initiatives by nonprofit organizations towards operating foodbanks are generally ineffective in developing countries where the foodbank ecosystem is at a preliminary stage. Establishing an integrated system comprising entities such as donors, foodbanks, food recovery and redistribution agencies (FRRA), and beneficiaries can be quite complex due to an underlying hierarchy, scale of operation, types of donors, and the severity of food insecurity of the beneficiaries. In this work, we present a strategic mixed-integer programming model to design an integrated foodbank network towards achieving an efficient, effective, and equitable food distribution mechanism for food-insecure beneficiaries while accounting for their age profile and nutritional requirements. We ensure cost-efficiency by minimizing the total system cost, effectiveness by discouraging food waste and unmet demand via charging penalties, and equity by adopting five variants of an egalitarian approach. We conduct a case study with a mix of real and realistically estimated data to design a foodbank network in Delhi (India) and present detailed analyses with insights for the practitioners. Specifically, the effects of foodbanks’ initial capacities, budget and strategic-to-operational cost constraints on the solution are identified. Among important observations, our analyses highlight when initiatives for collecting more ready-to-eat foods might be taken to relieve the pressure on the integrated system, and also help in identifying the conditions when investment in capacity building serves the beneficiaries’ interests better than direct spending

Accelerated bender’s decomposition algorithm and hybrid heuristics for multi-period planning of maternal healthcare facilities in India

This work addresses the challenge of improving availability and accessibility of maternal healthcare in India by presenting a multi-period planning problem of hierarchical and successively inclusive healthcare facilities. The problem is formulated as a mixed-integer linear programming model to minimize the overall cost, including the cost of establishing and upgrading the facilities, the cost of allocating/referring the mothers-to-be to the respective facilities and the penalty cost of demotivating the overburdening of the facilities in each time period. To solve the model effectively and efficiently, a Bender\u27s Decomposition Algorithm (BDA) with several acceleration strategies such as valid inequalities, disaggregated Benders cuts, rolling horizon heuristic and parallelism is developed. A Bender\u27s type heuristic is also tested by solving the master problem heuristically. Additionally, a Fix-and-Optimize (F&O) heuristic hybridized with Simulated Annealing (SA) enhanced by various search space reduction techniques is developed to obtain good quality solutions in a reasonable time for large instances. It is evident from the results of the computational experiments that the accelerated BDA and Bender type heuristic outperforms Gurobi. The hybrid F&O and SA is observed to be the most computationally efficient approach. A representative scenario in the Indian setting presents further evidence of the model\u27s applicability

Role of interpregnancy cervical encerclage in case of intrauterine insemination pregnancy

Cervical encerclage was first performed in 1902 in women with history of mid trimester abortion spontaneous preterm birth suggestive of cervical insufficiency, with the aim of preventing recurrent loss. Cervical insufficiency occurs in only 0.1% to 2% of all pregnancies. Cervical insufficiency has been defined as the inability of the uterine cervix to retain a pregnancy. Women with cervical insufficiency usually present with repetitive painless second trimester losses. There has not much been reported about cases in which interval cervical encerclage was done in non-pregnant state before start of ART procedure. We report a case with cervical insufficiency in a case of subseptate uterus who underwent interval cervical encerclage and carried pregnancy till term with positive outcome

Triple X syndrome: a rare case entity with premature ovarian failure, recurrent abortion and secondary infertility

Triple X syndrome is a sex chromosome abnormality characterised by extra X chromosome, occurring in 1 in 1000 female births. This condition often remains undiagnosed as most of them have normal phenotype, puberty and fertility. We report a case of Triple X syndrome with normal phenotype and intelligence presented with premature ovarian failure, recurrent abortion and secondary infertility. This case emphasizes the need for chromosomal analysis in women presenting with premature ovarian failure leading to recurrent abortion and secondary infertility

An Internet Based Aggregated Shopping Cart

This project mainly studies developments and establishments of an internet based aggregated shopping cart, specially to provide service for small buyers and small business holders, based on consolidated shopping and reverse auction at sellers side. This paper also explores the requirement and solutions for large volume discount to small buyers in both Business to Customer (B2C) and Business to Business(B2B) environments. For elective and e client navigation and representation of the entire structure of the product catalog system includes Tree map visualization technique and history bar to provide 2.5dimentional view. The whole platform possesses the versatility, convenience and includes the both Business to Customer (B2C) and Business to Business(B2B) environments. Dimensional view of contextual information