Combinatorial auctions for electronic business

Combinatorial auctions (CAs) have recently generated significant interest as an automated mechanism for buying and selling bundles of goods. They are proving to be extremely useful in numerous e-business applications such as e-selling, e-procurement, e-logistics, and B2B exchanges. In this article, we introduce combinatorial auctions and bring out important issues in the design of combinatorial auctions. We also highlight important contributions in current research in this area. This survey emphasizes combinatorial auctions as applied to electronic business situations

Design of multiunit electronic exchanges through decomposition

In this paper, we exploit the idea of decomposition to match buyers and sellers in an electronic exchange for trading large volumes of homogeneous goods, where the buyers and sellers specify marginal-decreasing piecewise constant price curves to capture volume discounts. Such exchanges are relevant for automated trading in many e-business applications. The problem of determining winners and Vickrey prices in such exchanges is known to have a worst-case complexity equal to that of as many as (1+m+n) NP-hard problems, where m is the number of buyers and n is the number of sellers. Our method proposes the overall exchange problem to be solved as two separate and simpler problems: 1) forward auction and 2) reverse auction, which turns out to be generalized knapsack problems. In the proposed approach, we first determine the quantity of units to be traded between the sellers and the buyers using fast heuristics developed by us. Next, we solve a forward auction and a reverse auction using fully polynomial time approximation schemes available in the literature. The proposed approach has worst-case polynomial time complexity and our experimentation shows that the approach produces good quality solutions to the problem

Late Gore Excluder endoprosthesis fabric tear leading to abdominal aortic aneurysm rupture 5 years after initial implant

Endoprosthesis fabric tear leading to abdominal aortic aneurysm rupture is a rare event. In this report, we describe a patient who presented with an abdominal aortic aneurysm rupture after a tear in the fabric of the Gore Excluder endoprosthesis (W. L. Gore and Associationes, Flagstaff, Ariz) 5 years after implantation. The reason for the fabric tear was unknown. The complication was successfully treated by relining the endograft with an aortic cuff and two iliac limbs. The patient experienced an uneventful recovery after the intervention

Combinatorial auctions for electronic business

Combinatorial auctions (CAs) have recently generated significant interest as an automated mechanism for buying and selling bundles of goods. They are proving to be extremely useful in numerous e-business applications such as e-selling, e-procurement, e-logistics, and B2B exchanges. In this article, we introduce combinatorial auctions and bring out important issues in the design of combinatorial auctions. We also highlight important contributions in current research in this area. This survey emphasizes combinatorial auctions as applied to electronic business situations

FORMULATION OF TRANSDERMAL PATCHES OF MICONAZOLE NITRATE AND ASSESMENT FOR DRUG RELEASE

Adhesive transdermal patches containing Miconazole Nitrate were prepared as an antifungal therapy. Eudragit RS 100 and Eudragit RL 100 were used in combination as matrix polymers. The patches were assessed for release using a model drug as Miconazole Nitrate by diffusion method. Subsequently, the permeation enhancement effect of DMSO and 2-pyrrolidone was studied. The patches have shown significant controlled release property of the model drug which can be used for a prolonged effect of the drug avoiding the first pass deactivation of Miconazole Nitrate. The patches were also evaluated using various parameters as weight variation, tensile strength, moisture uptake, moisture loss, drug content and other significant parameters. Selected formulations were subjected for their ex-vivo studies on rodent skin

A prospective randomized comparative study on fractures of lower third of both bones of the leg treated by interlock nailing of tibia with or without fixation of fibula

Background: In the treatment of fractures of the distal third of tibia and fibula treated by interlocking nail of tibia, the role of fixing the fibular fracture is not clearly defined. This study was conducted to assess the benefits of fixation of fibular fracture in distal third leg bones fractures.Methods: 95 patients were enrolled into study and divided randomly into two groups based on whether fibula fixed or not with interlock intramedullary nailing tibia. Patients were followed for an average period of 11 months both radiologically and clinically.Results: We observed that the average valgus angulation was significantly less (P =0.001) in the group where fibula was fixed. The outcome of the two groups for clinical ankle score, time of union and complication showed no difference (P ≥0.05). Conclusions: We concluded that fixation of fibula decrease the malalignment of tibia in distal third fractures of tibia and fibula treated with interlocking nail of tibia.