Vertical Foreclosure with the Choice of Input Specifications

This paper develops an equilibrium model of vertical foreclosure with the choice of input specifications. In this model, vertical foreclosure occurs as the upstream division of the integrated firm makes a specialized input for its sister downstream division while it would, as an independent firm, provide a generalized input. The changes in incentives whit vertical integration allows the upstream firm to internalize the benefit of raising the rival firm's cost at the downstream level. The choice of a specialized input by the integrated firm serves as a natural commitment mechanism not to supply the rival downstream firms, and thus enables us to dispense with the controversial price commitment assumption in the literature. We derive conditions for equilibrium vertical foreclosure to occur and discuss its welfare consequences

Equilibrium Vertical Foreclosure with Investment

One of the most enduring controversies in antitrust concerns the potential foreclosure effects of vertical integration. In a recent paper, Ordover, Saloner and Saloner and Salop (1990) construct a model of vertical integration in which vertical foreclosure emerges as the equilibrium outcome. However, as is well-known, OSS's result breaks down if the vertically integrated firm cannot make the price commitment. In this paper, we reexamine the foreclosure theory of vertical integration by extending OSS's model to include upstream market power and investments. Cost-reducing investments introduce a channel through which the integrated firm can credibly commit itself to a higher input price at which it is willing to supply the unintegrated downstream firm. We show that a profitable but anticompetitive (both for consumer welfare and for aggregate efficiency) vertical causing hold-out problems between the input suppliers. In contrast to OSS's model, where vertical integration (even with commitment) is not effective under Cournot downstream competition, vertical integration in our model can be both effective and anticompetitive even under Cournot downstream competition

Automated Brittle Fracture Rate Estimator for Steel Property Evaluation Using Deep Learning After Drop-Weight Tear Test

This study proposes an automated brittle fracture rate (BFR) estimator using deep learning. As the demand for line-pipes increases in various industries, the need for BFR estimation through dropweight tear test (DWTT) increases to evaluate steel's property. Conventional BFR or ductile fracture rate (DFR) estimation methods require an expensive 3D scanner. Alternatively, a rule-based approach is used with a single charge-coupled device (CCD) camera. However, it is sensitive to the hyper-parameter. To solve these problems, we propose an approach based on deep learning that has recently been successful in the fields of computer vision and image processing. The method proposed in this study is the first to use deep learning approach for BFR estimation. The proposed method consists of a VGG-based U-Net (VU-Net) which is inspired by U-Net and fully convolutional network (FCN). VU-Net includes a deep encoder and a decoder. The encoder is adopted from VGG19 and transferred with a pre-trained model with ImageNet. In addition, the structure of the decoder is the same as that of the encoder, and the decoder uses the feature maps of the encoder through concatenation operation to compensate for the reduced spatial information. To analyze the proposed VU-Net, we experimented with different depths of networks and various transfer learning approaches. In terms of accuracy used in real industrial application, we compared the proposed VU-Net with U-Net and FCN to evaluate the performance. The experiments showed that VU-Net was the accuracy of approximately 94.9 %, and was better than the other two, which had the accuracies of about 91.8 % and 93.7 %, respectively.11Ysciescopu

Optimal compatibility in systems markets

We investigate private and social incentives for standardization to ensure market-wide system compatibility in a two-dimensional spatial competition model. We develop a new methodology to analyze competition on a torus and show that there is a fundamental conflict of interests between consumers and producers over the standardization decision. Consumers prefer standardization with full compatibility because it offers more variety that confers a better match with their ideal specifications. However, firms are likely to choose the minimal compatibility to maximize product differentiation and soften competition. This is in sharp contrast to the previous literature that shows the alignment of private and social incentives for compatibility

Characteristics of blood tests in patients with acute cerebral infarction who developed symptomatic intracranial hemorrhage after intravenous administration of recombinant tissue plasminogen activator

Objective Patients suspected as having acute ischemic stroke usually undergo blood tests, including coagulation-related indexes, because thrombocytopenia and coagulopathy are contraindications for recombinant tissue plasminogen activator (rtPA) administration. We aimed to identify blood test indexes associated with symptomatic intracranial hemorrhage (sICH) in patients with acute ischemic stroke who received intravenous rtPA. Methods This retrospective observational study included patients diagnosed with acute ischemic stroke who were treated with intravenous rtPA at the emergency department of a tertiary hospital in Seoul between February 2008 and January 2018. Blood test indexes were compared between the sICH and non-sICH groups. Logistic regression and receiver-operating characteristic curve analyses were performed. Results In this study, 375 patients were finally included. Of 375 patients, 42 (11.2%) showed new intracranial hemorrhage on follow-up brain computed tomography, of whom 14 (3.73%) had sICH. Platelet count, aspartate aminotransferase and lactate dehydrogenase levels were significantly different between the sICH and non-sICH groups, and platelet count showed statistical significance in the regression analysis. Significantly lower platelet counts were observed in the sICH group than in the non-sICH group (174,500 vs. 228,000/mm3, P=0.020). The best cutoff platelet count was 195,000/mm3, and patients with platelet counts of <195,000/mm3 had a 5.4- times higher risk of developing sICH than those with platelet counts of ≥195,000/mm3. Conclusion Platelet count was the only independent parameter associated with sICH among the blood test indexes. Mild thrombocytopenia may increase the risk of sICH after intravenous administration of rtPA

A Case of Stent Graft Infection Coupled With Aorto-Esophageal Fistula Following Thoracic Endovascular Aortic Repair in a Complex Patient

The incidence of peri-stent graft infection (PGI) following thoracic endovascular aortic repair (TEVAR) is low, but the associated mortality rates are extremely high. The diagnosis of this complication can be difficult due to nonspecific symptoms. Here, we report a case of PGI combined with an aorto-esophageal fistula (AEF) diagnosed by computed tomography (CT) and positron emission tomography (PET) imaging after TEVAR. A 50-year-old woman with a history of diabetes mellitus and chronic hemodialysis had received a stent graft for a contained rupture of a pseudoaneurysm of the descending thoracic aorta. Three months after stent-grafting, she experienced back pain. CT and PET imaging suggested a PGI. The patient underwent surgical treatment for PGI with AEF

Abdominal Aortic Aneurysm Repair in Patient with a Renal Allograft: A Case Report

Renal transplant recipients requiring aortic reconstruction due to abdominal aortic aneurysm (AAA) pose a unique clinical problem. The concern during surgery is causing ischemic injury to the renal allograft. A variety of strategies for protection of the renal allograft during AAA intervention have been described including a temporary shunt, cold renal perfusion, extracorporeal bypass, general hypothermia, and endovascular stent-grafting. In addition, some investigators have reported no remarkable complications of the renal allograft without any specific measures. We treated a case of AAA in a patient with a renal allograft using a temporary aortofemoral shunt with good result. Since this technique is safe and effective, it should be considered in similar patients with AAA and previously placed renal allografts