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This study examines when firms offer higher product quality. We measure product quality by examining four different inflight amenities provided by airlines: Wi-Fi, seat size, entertainment, and seat power. Using daily flight level data for over 800 routes and spanning nine weeks in third quarter of 2015 we observe that carriers were actively retrofitting aircraft to expand their inflight amenity offerings. We find significantly lower product quality (Wi-Fi, entertainment, and power) on more concentrated routes. While considerable research has been done on airline pricing, less well known is how airlines pursue other revenue streams from ancillary services. Recent work by Brueckner et al. (2015) explores the role of baggage fees in airline pricing. We examine additional revenue streams provided by Wi-Fi and entertainment inflight amenities. We find that carriers are lowering the posted base ticket prices on routes with Wi-Fi and entertainment and then charging passengers for using these amenities. The IV price estimates reveal that magnitude of the posted fare reduction is larger than the additional revenue generated from the inflight amenity.

Ad blocking may benefit all stakeholders with better quality ads through a signaling mechanism.

It is difficult to segment Glioma and its internal structure because the Glioma boundaries have edemas and complex internal structures. This paper proposes a new optimized, integrated 3D U-Net network to achieve accurate segmentation of Glioma and internal subareas. The contribution of this paper is twofold, it studies the clinical path of patients with Glioma and constructs an optimized 3D U-Net deep learning algorithm by combining them with the radiologic feature set. The proposed model was validated in the published Glioma operation data set of multi-modal MRI resonance images and clinicians manual segmentation data. The model can accurately segment the MRI multi-modality images of Glioma and intra-tumour nodes and achieve the multi-modality prediction of the overall survival period of patients. The experimental results further indicated that the segmentation accuracy of the proposed method was higher than other sophisticated methods. The Dice similarity coefficients of the whole tumor (WT) region, the core tumor (CT) region, and the augmentation / enhanced tumor (ET) region, were 0.9632, 0.8763, and 0.8421, respectively, which are better than the clinical experts’ manual segmentation results. Hence, this research can effectively promote the development of deep learning clinical precise diagnosis and medical technology for Glioma.

This paper introduces strategic agents into a two-sided market. We model strategic agents as advertisers who can invest in ad quality, which in turn affects readers, platforms and themselves. When platforms can choose prices on both the reader side and the advertiser side, strategic agents intensify competition, leading to lower prices and profits for the platforms. However, when prices on the reader side are restricted to be zero, equilibrium prices on the advertiser side can be higher or lower under strategic agents. We also investigate the interplay between strategic agents and platform asymmetry, and analyze platforms’ incentive to invest in content quality. Our results suggest that strategic agents increase the degree of platform asymmetry and make it harder for the disadvantaged platform to compete. However, strategic agents may raise or lower platforms’ incentive to invest in content quality.

Aiming at the difference in the segmentation performance of the three segmentation target regions in the glioma image segmentation task based on the fully convolutional neural network, we propose a comprehensive evaluation method of neural network performance based on four evaluation indices. In addition, we analyze the performance and characteristics of neural network in the segmentation task of glioma, study the segmentation performance of neural network in the whole tumor (WT), tumor core (TC) and enhanced tumor (ET) regions, and propose a deep learning algorithm based on multiple networks in parallel. In this paper, the input image of the two-dimensional neural network is sliced, and the input of the three-dimensional neural network is processed in two ways: overlapping and non-overlapping, and in the image post-processing part, the three-dimensional image is reconstructed before the evaluation index is calculated. This article uses four evaluation indexes, which are Dice, Sensitivity, PPV, and Hausdorff, for the three segmentation target regions, and performs RSR* weight calculation, and finally performs a comprehensive evaluation. Experimental results show that Vnet has the best comprehensive segmentation performance, FCN-8s has the best segmentation performance in the TC area, Unet++ has the best segmentation performance in the ET area, and Vnet has the best segmentation performance in the WT area. Based on this, we propose a FUV multi-network parallel algorithm, combined with a reverse attention mechanism to improve the segmentation accuracy of the three segmentation target regions.

In this study, the self-extracted constipation treatment of traditional Chinese medicine extracts was applied to constipated rats. To explore the mechanism and role of the Chinese medicine for the treatment of constipation, the 16S rRNA sequencing and qRT-PCR technology were used to analyze the intestinal flora. We found that the relative abundance of Firmicutes with constipation was significantly higher accounted for 86.7%, while the gut microbiota was significantly changed after taking a certain dose of Chinese medicine, greatly increased the relative abundance of Lactobacillus accounted for 23.1%, enhanced the symbiotic relationships of Lactobacillus with other intestinal flora. The total copies of intestinal bacteria in the constipated rats decreased after taking the traditional Chinese medicine. Finally, this study results provides a theoretical basis for the treatment and understand the mechanism and effect of traditional Chinese medicine on rate constipation.

Neuroimaging technologies have improved our understanding of deception and also exhibit their potential in revealing the origins of its neural mechanism. In this study, a quantitative power analysis method that uses the Welch power spectrum estimation of functional near-infrared spectroscopy (fNIRS) signals was proposed to examine the brain activation difference between the spontaneous deceptive behavior and controlled behavior. The power value produced by the model was applied to quantify the activity energy of brain regions, which can serve as a neuromarker for deception detection. Interestingly, the power analysis results generated from the Welch spectrum estimation method demonstrated that the spontaneous deceptive behavior elicited significantly higher power than that from the controlled behavior in the prefrontal cortex. Meanwhile, the power findings also showed significant difference between the spontaneous deceptive behavior and controlled behavior, indicating that the reward system was only involved in the deception. The proposed power analysis method for processing fNIRS data provides us an additional insight to understand the cognitive mechanism of deception.

This paper develops an equilibrium framework to structure informational and non-informational content for ad messages in various market settings. The novel element in this framework is in assessing the viewer’s individual incentives to attend to elements of an ad relative to some other, non-ad-viewing activity. We prescribe ad content strategies across various (i) market factors, (ii) advertising goals, and (iii) ad formats (skippable versus non-skippable). Our framework classifies many advertising content strategies observed in practice. First, an advertiser can structure content to induce curiosity for continued viewing, a tactic prevalent in clickbait ads and “mystery ads”. Second, skippable ads have a lower return to non-informational content relative to non-skippable ads and explains the industry perception that ads on digital media are of lower copy quality than traditional ads. Finally, skippable ads are better suited for less ambitious advertising goals, such as brand awareness, when attention-spans are shorter. This latter result justifies the value proposition for the skippable format used by digital media platforms, such as YouTube and Facebook.

The Dibbling machine is the core part of the seeder, which plays an important role in precision and semi-precision seeding. In this paper, the suction precision seeder has strict requirements on seeds. The high speed seeding adaptability of disc precision seeder is poor and the seeds need to be graded. Because of the limitation of the landform land parcel, these large equipment can not complete the seeding operation of the relatively complex land parcel such as the small parcel or even the hilly area. The seeder overcomes the shortcomings of suction precision seeder and disc precision seeder, it can realize precise seeding of seeds of different specifications. The design has the advantages of simple structure, stable work, easy operation and low cost. It can realize fixed distance seeding, which significantly improves the uniformity and efficiency and meets the requirements of practical application. Finally, SolidWorks 3D modeling software is used to carry out solid modeling design for each part of the parts and complete the overall assembly of the hand-pushed roller seeder.

BACKGROUND: This study aims to investigate the clinical efficacy of transoral laser microsurgery and open partial laryngectomy (OPL) in treating T1-2 laryngeal cancer. METHODS: A retrospective analysis was conducted of 182 patients with T1-2 cancer with anterior vocal commissure (AVC) involvement. The local control (LC), disease-free survival (DFS) and overall survival (OS) rates at 5-year follow-up and the influencing factors were analyzed. RESULTS: No significant difference was observed in the LC or DFS rates between the two groups at 3- and 5-year follow-up. No significant difference was found between the two groups with T1-stage disease. The 5-year LC rates were significantly different from patients with grade 3 or 4 tumors on indirect laryngoscopy and patients with class III or IV tumors on the modified Mallampati test (MMT) (log-rank test: χ(2)=8.037, P=0.005). The 3-year LC rate of OPL in the depth of pathological infiltration (3–5 mm) group was found to be significantly higher than that of TLM. Significant differences in pathological infiltration depth (3–5 mm) existed between the two groups (log-rank test: χ(2)=5.786, P=0.016). CONCLUSIONS: T1 lesions are generally limited and superficial, and laser surgery can be well-controlled. For patients with difficult airway exposure, surgeons should have extensive surgical experience and skills. It is recommended that a variety of equipment should be ready so that surgeons can convert to open surgery at any time. For patients with a deep infiltration depth, surgeons should examine laryngoscopy imaging results before surgery.

The hemiplegic rehabilitation state diagnosing performed by therapists can be biased due to their subjective experience, which may deteriorate the rehabilitation effect. In order to improve this situation, a quantitative evaluation is proposed. Though many motion analysis systems are available, they are too complicated for practical application by therapists. In this paper, a method for detecting the motion of human lower limbs including all degrees of freedom (DOFs) via the inertial sensors is proposed, which permits analyzing the patient’s motion ability. This method is applicable to arbitrary walking directions and tracks of persons under study, and its results are unbiased, as compared to therapist qualitative estimations. Using the simplified mathematical model of a human body, the rotation angles for each lower limb joint are calculated from the input signals acquired by the inertial sensors. Finally, the rotation angle versus joint displacement curves are constructed, and the estimated values of joint motion angle and motion ability are obtained. The experimental verification of the proposed motion detection and analysis method was performed, which proved that it can efficiently detect the differences between motion behaviors of disabled and healthy persons and provide a reliable quantitative evaluation of the rehabilitation state.

The price discrimination literature typically makes the assumption of no consumer arbitrage. This assumption is increasingly violated in the digital economy, where coupons are traded with increased frequency online. In this paper, we analyze the welfare impacts of coupon trading using a modified Hotelling model where firms send coupons to poach each other’s loyal customers. The possibility of coupon trading renders this important instrument for price discrimination less effective. Moreover, coupon distribution has unintended consequences when coupon traders sell coupons back to a firm’s loyal customers. Consequently, coupon trading may reduce firms’ incentive to distribute coupons, leading to higher prices and profits. We find that, an increase in coupon distribution cost lowers promotion frequency but raises promotion depth, and an increase in the fraction of coupon traders lowers both promotion frequency and promotion depth.

We explore the firm quasi-dynamics (entry/exit and growth) in the Chinese manufacturing industries and investigate how these dynamics vary across regions. Our results show that relative to provinces with less developed economies, in provinces with more developed economies: (1) There are higher shares of new firms; (2) New firms are smaller and more labor-intensive; (3) Firms exit at a quicker rate and surviving firms grow faster. These results point toward cross-region differences in market efficiency in terms of how much it costs a firm to enter or exit the market. Our findings shed light on how firms should adapt their strategies across regions and how the government should create sound policies on industrial upgrading and relocation.

Background Recently, deep learning technologies have rapidly expanded into medical image analysis, including both disease detection and classification. As far as we know, migraine is a disabling and common neurological disorder, typically characterized by unilateral, throbbing and pulsating headaches. Unfortunately, a large number of migraineurs do not receive the accurate diagnosis when using traditional diagnostic criteria based on the guidelines of the International Headache Society. As such, there is substantial interest in developing automated methods to assist in the diagnosis of migraine. Methods To the best of our knowledge, no studies have evaluated the potential of deep learning technologies in assisting with the classification of migraine patients. Here, we used deep learning methods in combination with three functional measures (the amplitude of low-frequency fluctuations, regional homogeneity and regional functional correlation strength) based on rs-fMRI data to distinguish not only between migraineurs and healthy controls, but also between the two subtypes of migraine. We employed 21 migraine patients without aura, 15 migraineurs with aura, and 28 healthy controls. Results Compared with the traditional support vector machine classifier, which has an accuracy of 83.67%, our Inception module-based convolutional neural network approach showed a significant improvement in classification output (over 86.18%). Our data also indicate that the Inception module-based CNN performs better than the AlexNet-based CNN (Inception module-based CNN reached an accuracy of 99.25%). Finally, we also found that regional functional correlation strength (RFCS) could be regarded as the optimum input out of the three indices (ALFF, ReHo, RFCS). Conclusions Overall, our study shows that combining the three functional measures of rs-fMRI with deep learning classification is a powerful method to distinguish between migraineurs and healthy individuals. Our data also highlight that deep learning-based frameworks could be used to develop more complicated models or systems to aid in clinical decision making in the future. Electronic supplementary material The online version of this article (10.1186/s12938-018-0587-0) contains supplementary material, which is available to authorized users.

Advances in information technology have greatly enhanced firms’ ability to collect, market and utilize consumer information. As the market for consumer information expands rapidly, businesses are armed with unprecedented means to target any group of consumers they desire. This has important and far-reaching impacts on consumer welfare. In this paper we analyze the welfare impacts of price discrimination facilitated by increasing qualities of consumer information. We employ a two-dimensional spatial differentiation model where consumer information is available on one dimension, and better information leads to more refined price discrimination. We find that as information quality improves, equilibrium prices and profits monotonically increase while consumer surplus and social surplus monotonically decrease. Price discrimination has a reduced demand elasticity effect which becomes stronger when consumer information becomes more precise. Our results suggest that regulators need to pay more attention to the potential damage to consumer welfare by the increasing collection and utilization of consumer information. We also endogenize firms’ information acquisition decisions.

Background: Nowadays, social media tools such as short message service, Twitter, video, and web-based systems are more and more used in clinical follow-up, making clinical follow-up much more time- and cost-effective than ever before. However, as the most popular social media in China, little is known about the utility of smartphone WeChat application in follow-up. In this study, we aimed to investigate the feasibility and superiority of WeChat application in clinical follow-up. Methods: A total of 108 patients diagnosed with head and neck tumor were randomized to WeChat follow-up (WFU) group or telephone follow-up (TFU) group for 6-month follow-up. The follow-ups were delivered by WeChat or telephone at 2 weeks, 1, 2, 3, and 6 months to the patients after being discharged. The study measurements were time consumption for follow-up delivery, total economic cost, lost-to-follow-up rate, and overall satisfaction for the follow-up method. Results: Time consumption in WFU group for each patient (23.36 ± 6.16 min) was significantly shorter than that in TFU group (42.89 ± 7.15 min) (P < 0.001); total economic cost in WFU group (RMB 90 Yuan) was much lower than that in TFU group (RMB 196 Yuan). Lost-to-follow-up rate in the WFU group was 7.02% (4/57) compared with TFU group, 9.80% (5/51), while no significance was observed (95% confidence interval [CI]: 0.176–2.740; P = 0.732). The overall satisfaction rate in WFU group was 94.34% (50/53) compared with 80.43% (37/46) in TFU group (95% CI: 0.057–0.067; P = 0.034). Conclusions: The smartphone WeChat application was found to be a viable option for follow-up in discharged patients with head and neck tumors. WFU was time-effective, cost-effective, and convenient in communication. This doctor-led follow-up model has the potential to establish a good physician-patient relationship by enhancing dynamic communications and providing individual health instructions. Trial Registration: Chinese Clinical Trial Registry, ChiCTR-IOR-15007498; http://www.chictr.org.cn/ showproj.aspx?proj=12613.

Background The safety and efficacy of sublingual immunotherapy (SLIT) have been demonstrated in the recent 2 decades. However, the data is still mixed regarding the efficacy of house dust mite (HDM) SLIT. The objective of this work was to evaluate the different clinical efficacy SLIT in patients with allergic rhinitis (AR) according to different durations of treatment. Methods A total of 500 subjects with HDM-induced AR were randomized to receive SLIT with Dermatophagoides farinae (Der.f) drops or pharmacotherapy with oral antihistamines. Patients in the SLIT group were further divided into SLIT1, SLIT2, and SLIT3 subgroups. After SLIT completion, a yearly follow-up visit was given to patients in the SLIT1 and SLIT2 subgroups. The total nasal symptom score (TNSS), the proportion of medication withdrawal, the visual analogue scale (VAS) score, and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores were assessed at each monthly visit. Results Comparing with the baseline value, TNSS, VAS, and RQLQ were significantly improved in 3 SLIT subgroups after treatment (p 0.05) with respect to the completion value. No severe systemic adverse events (AEs) were reported. Conclusion The randomized study suggested that 3-year courses of SLIT in patients with AR was more efficacious than 1-year or 2-year courses. Furthermore, patients achieved 1-year long-term clinical benefits from HDM SLIT.

Digital media platforms commonly use the skippable ad format, which gives a viewer the option to skip part of an advertisement after seeing some limited information, and jump directly to the desired content. It also enables these platforms to charge advertisers only when viewers attend to the entire ad. We develop a dynamic model of a viewer receiving incremental information from the advertiser and embed it in a two-sided market setting with an advertising market. Our results show that skippable ads can be less effective overall in converting existing viewers to advertisers. However, skippable ads bring more viewers to the platform and, in turn, induce more advertisers. This suggests that a switch to the skippable format is a profitable strategy for an emerging and growing platform, but not necessarily for one in a saturated market.

In 2010, Spirit airlines announced that it would start charging passengers for carry-on baggage. Using a vector of route level characteristics, we construct a matched group consisting of routes which best match those served by Spirit (treated group). We then run a diff-in-diff estimation using the treated and matched group, and examine the impact of Spirit's baggage fee policy on its rivals' ticket prices. Our results show that Spirit's rivals reduce their prices by about 5.8% after Spirit charges carry-on baggage fee. Looking into potentially heterogeneous impacts, we find that the policy impact is smaller on low-cost carriers relative to legacy carriers. We also take into account subcontracting status. Relative to non-subcontracting carriers, those which subcontract operations to regional carriers reduce their prices further by more than 10%, including average price (linear or log) and various points on the price distribution. We also develop a stylized theory model to help better understand our empirical findings.

In order to realize the real-time monitoring of the operation state and predict the possible faults of a steam turbine, a mobile APP based on the steam turbine operation monitoring and health management system is proposed in this paper. Firstly, some common faults which will be encountered in the operation of steam turbine are analyzed and the mechanism and characteristics of the faults are studied. Secondly, the hardware and software platform on the PC are built to diagnose the fault and analyze the trend by combining the methods of wavelet packet decomposition and BP neural network. Finally, the APP on the mobile terminal for the real-time operation monitoring of the steam turbine is developed. Furthermore, the test results of the mobile APP demonstrate that the developed mobile APP can effectively diagnose the fault and predict the trend. It also proved that the developed mobile APP can make the operation monitoring and health management system of the steam turbine run stably and meet the practical application requirements.

Advancing in information technology has empowered firms with unprecedented flexibility when interacting with each other. We compare welfare results in a vertical market (e.g., manufacturers and retailers) for several types of pricing strategies depending upon the following: (1) which side (retailers or manufacturers) chooses retail prices; and (2) whether there is revenue sharing or linear pricing between the two sides. Our results are as follows. Under revenue sharing, retail prices (and thus industry profits) are higher if and only if they are chosen by the side featuring less competition. Under linear pricing, however, retail prices are higher if they are chosen by the side featuring more competition (for linear demand functions). Relative to linear pricing, revenue sharing always leads to lower retail prices, higher consumer surplus and social surplus. However, the comparison on industry profits depends on the demand elasticity ratios. Revenue sharing raises industry profits when the elasticity ratios are small, but the results are reversed when the elasticity ratios are large. Copyright © 2014 John Wiley & Sons, Ltd.

We follow the framework in Arya and Mittendorf's 2011 Rand Journal of Economics paper but extend their analysis by investigating supplier(s)' equilibrium choices of disclosure or confidentiality regarding their contract terms with the downstream retailers. In the case of a common supplier, we find that the unique subgame perfect Nash equilibrium (SPNE) is for the supplier to choose disclosure. This private incentive is opposite to social incentive, which calls for the regulator to choose confidentiality. In the case of dedicated suppliers, however, there are multiple SPNE due to coordination issues between the suppliers. The case which maximizes social surplus – disclosure – can be supported as a SPNE, together with the case of confidentiality, which maximizes supplier profits at the cost of everyone else. Copyright © 2014 John Wiley & Sons, Ltd.

Platforms such as Uber, Lyft and Airbnb serve two-sided markets with drivers (property owners) on one side and riders (renters) on the other side. Some agents multi-home. In the case of ride-sharing, a driver may drive for both Uber and Lyft, and a rider may use both apps and request a ride from the company that has a driver close by. In this paper, we are interested in welfare implications of multi-homing in such a market. Our model abstracts away from entry/exit by drivers and riders as well as pricing by platforms. Both drivers' and riders' surpluses are determined by the average time between a request and the actual pickup. The benchmark setting is a monopoly platform and the direct comparison is a single-homing duopoly. The former is more efficient since it has a thicker market. Next, we consider two multi-homing settings, multi-homing on the rider side and multi-homing on the driver side. Relative to single-homing duopoly, we find that multi-homing on either side improves the overall welfare. However, multi-homing drivers potentially benefit themselves at the cost of single-homing drivers. In contrast, multi-homing riders benefit themselves as well as single-homing riders, representing a more equitable distribution of gains from multi-homing.

With the aging population problem getting more and more aggravated, the number of hemiplegia patients increases rapidly, which results in the increasing requirement of rehabilitation training for regaining the body movement function. Taking advantages of rehabilitation robots makes the rehabilitation training more scientific and efficient compared to traditional rehabilitation measures such as manual training. By now, many types of rehabilitation robots have been proposed by researchers. However, from the view of the physiological structure, many of them can't well fit the motion characteristics. Ankle plays an important role in standing, walking and so on. As the motion of these robots is different from the motion characteristics of ankles, it would make an undesired influence on the training effect. Rehabilitation robots have many structures, and they are mainly serial mechanism and parallel mechanism. However, serial mechanism is inconvenient to package. In this paper, a new type of parallel mechanism with six degrees of freedom is proposed. The basic principle structure of the ankle rehabilitation robot in this paper would be done according to the medical requirement and engineering requirement. After determine the programmer of the mechanism, the degrees of freedom of the mechanism would be calculated by the screw theory, and the Solid works software would be used to simulate and analyze the movement of the mechanism so that the torque and power calculation of key positions of the mechanism would be done with the simulation data. At last, the specific design of the mechanism would be finished with the obtained feasible basic principle structure. The function of different components would be introduced and this paper would check the key components to ensure the reliability of the mechanism.

This study aimed to compare the accuracy of CT and MRI in determining the invasion of thyroid cartilage by and the T staging of laryngeal carcinoma with anterior vocal commissure (AVC) involvement. A total of 26 cases of laryngeal carcinomas with AVC involvement from May 2012 to January 2014 underwent enhanced CT and MRI scan, out of whom 6 patients also underwent diffusion-weighted magnetic resonance imaging(DWI). T staging and thyroid cartilage involvement were evaluated. All the surgical specimens underwent serial section and were reviewed by two senior pathologists independently. When compared with pathologic staging, the accuracy was 88.46% (23/26) of MRI scan (with a 95% confidence interval 37~77%) and 57.69% (15/26) of CT scan (with a 95% confidence interval 70~98%), respectively (P

We study the effects of introducing a Most-Favored Customer (MFC) clause on price competition among major consumer electronics retailers. Our data spans the periods before and after the introduction of an MFC clause by Best Buy, which occurred between April 1, 2003 and March 31, 2004. After controlling for various factors (including product life-cycle and seasonality effects), we find that, on average, Best Buy lowered its prices by 1.6% after introducing the MFC clause. Its competitors responded by cutting prices further: Buy.com by 3.5%, Circuit City by 2.2%, CompUSA by 3.2%, and Sears by 0.4%. We conclude that Best Buy's MFC adoption reduced prices.

This paper shows the conditions for consumer sorting to be profitable. Sorting of low quality goods dampens their substitutability with high quality goods and can raise firm's profit even when sorting lowers profit from low quality sales considered alone.

Research Summary: Platform owners sometimes enter complementors' product spaces and compete against them. Using data from Amazon.com to study Amazon's entry pattern into third‐party sellers' product spaces, we find that Amazon is more likely to target successful product spaces. We also find that Amazon is less likely to enter product spaces that require greater seller efforts to grow, suggesting that complementors' platform‐specific investments influence platform owners' entry decisions. While Amazon's entry discourages affected third‐party sellers from subsequently pursuing growth on the platform, it increases product demand and reduces shipping costs for consumers. We consider the implications of these findings for complementors in platform‐based markets. Managerial Summary: Platform owners can exert considerable influence over their complementors' welfare. Many complementors with successful products are pushed out of markets because platform owners enter their product spaces and compete directly with them. To mitigate such risks, complementors could build their businesses by aggregating nonblockbuster products or focusing on products requiring significant platform‐specific investments to grow. They should also develop capabilities in new product discovery so that they could continually bring innovative products to their platforms.

We follow the framework in Arya and Mittendorf (2011) but extend their analysis by investigating supplier(s)' equilibrium choices of disclosure or confidentiality regarding their contract terms with the downstream retailers. In the case of a common supplier, we find that the unique SPNE is for the supplier to choose disclosure. This private incentive is opposite to social incentive which calls for the regulator to choose confidentiality. In the case of dedicated suppliers, however, there are multiple SPNE due to coordination issues between the suppliers. The case which maximizes social surplus -- disclosure -- can be supported as a SPNE, together with the case of confidentiality which maximizes supplier profits at the cost of everyone else.

Advancing in information technology has empowered firms with unprecedented flexibility when interacting with each other. We compare welfare results in a vertical market (e.g., manufacturers and retailers) across several types of pricing strategies depending upon (1) which side (retailers or manufacturers) chooses retail prices and (2) whether there is revenue sharing or linear pricing between the two sides. Our results are as follows. Under revenue sharing, retail prices (and thus industry profits) are higher if and only if they are chosen by the side featuring less competition. Under linear pricing, however, retail prices are higher if they are chosen by the side featuring more competition (for linear demand functions). Relative to linear pricing, revenue sharing always leads to lower retail prices, higher consumer surplus and social surplus. However, the comparison on industry profits depends on the demand elasticity ratios. Revenue sharing raises industry profits when the elasticity ratios are small, but the results are reversed when the elasticity ratios are large.

We analyze product differentiation in a multi-dimensional model with non-uniform consumer distribution. The level of product differentiation is measured by both unit transport costs and firm locations. Our analysis concerns both measures. First, fixing firms' locations, we show that equilibrium prices can increase or decrease with unit transport cost. The overall result depends on the interplay of a shifting effect and a rotating effect -- the latter exists only in multi-dimensional models. Second, fixing unit transport costs, we find that under non-uniform distribution, there may exist no equilibrium where firms maximize differentiation on one dimension but minimize differentiation on other dimensions. Instead, there may exist equilibrium where firms choose intermediate locations, contrary to the common findings in existing studies which assume uniform distribution.

Trust is an important issue in distributed systems. Recommendation trust has very strong subjectivity. Mendacious recommendation will mislead trust evaluation and threat the system security. To address the problem, this paper proposed a trust computing method based on feedback credibility. Feedback credibility is used to evaluate the authenticity of the recommendation trust by computing the difference between the recommendation trust and mean recommendation trust. The time attribute of feedback information was identified by time decay function. Simulation experiments show that this method can reduce effectively the impact of mendacious recommendation trust, and compute accurately the trust of entity according to entity’s behaviors. It provides reliable information to correctly make the security decisions for the system.

This paper investigates the roles of price-matching guarantee as a response to `showrooming' (quality free-riding) and as a tool for predation. Employing a duopoly vertical differentiation model, we find that price-matching guarantee raises consumer surplus but its impact on social surplus is ambiguous. We identify two effects of price-matching guarantee on firms' profits. The change of sales effect improves the high quality firm's profit at the cost of its low quality rival while the intensified competition effect reduces both firms' profits. When the level of quality free-riding is sufficiently high, the change of sales effect dominates and price-matching guarantee raises the high quality firm's profit. On the other hand, when the level of quality free-riding is low, a price-matching guarantee lowers both firms' profits, suggesting a possible anti-trust rationale if adopted. That is, the high quality firm adopts a price-matching guarantee to drive the low quality firm out of market (predation through price-matching).

Using a dynamic overlapping-generations model, we show that loyalty rewards robustly facilitate tacit collusion. We compare the sustainability of tacit collusion when uniform prices are used, when loyal customers are rewarded without using commitment, and when loyalty rewards are implemented by committing to offering customers either lower fixed repeat-purchase prices or fixed repeat-purchase discounts. We find that, relative to uniform prices, rewarding loyalty without using commitment on the equilibrium path makes tacit collusion easier to sustain, because a deviating firm is unable to steal one period of industry profit before losing all future profits. When loyalty rewards are offered by firms committing to repeat-purchase prices, collusion is even easier to sustain, because a deviating firm cannot renege on its discounted price for repeat-purchase customers. When firms commit to repeat-purchase discounts, they also commit to lowering the price for their repeat-purchase customers if they undercut the regular price, rendering tacit collusion to be even more readily sustainable. Our results hold whether products are homogeneous or horizontally differentiated as in a Hotelling model.

The price discrimination literature typically makes the assumption of no consumer arbitrage. This assumption is increasingly violated in the digital economy, where coupons are traded with increased frequency online. In this paper, we analyze the welfare impacts of coupon trading using a modified Hotelling model where firms send coupons to poach each other's loyal customers. The possibility of coupon trading renders this important instrument for price discrimination less effective. Moreover, coupon distribution has unintended consequences when coupon traders sell coupons back to a firm's loyal customers. Consequently, coupon trading may reduce firms' incentive to distribute coupons, leading to higher prices and profits. We find that, an increase in coupon distribution cost lowers promotion frequency but raises promotion depth, and an increase in the fraction of coupon traders lowers both promotion frequency and promotion depth.

Unrestricted flows of information usually improve efficiency. The recent growth of the Internet as a medium of communication and commerce, combined with the development of sophisticated software tools have paved the road for the collection and analysis of a vast amount of data about consumers. Firms who possess such information can target individual consumers (or certain groups of consumers) more effectively. We investigate whether consumers can claim some of the value of their own private information, while at the same time efficient flows of information are guaranteed. We address this question in a principal-agent adverse selection model. Prior to the contracting stage, the agent (consumer) chooses how much (precision) of his private information to sell to the principal. This gives rise to a signaling game that precedes the adverse selection stage. We show that there exists a pooling efficient equilibrium, where both agent types sell all their information to the principal.

This article explores the features and the role of the anterior vocal commissure (AVC) structure and the surface morphologies of glottic carcinomas with AVC involvement to provide a reference for the selection of transoral carbon dioxide (CO2) laser surgery. A total of 31 cases of glottic carcinomas with AVC involvement from May 2012 to January 2014 were included. All patients underwent electronic laryngoscopic examinations and computed tomography scans to determine the surface morphology. After surgery, the tumor specimens were resected integrally, and axial serial sections parallel to the plane of vocal cords were taken to explore the features and possible invasion paths of the glottic carcinomas with AVC involvement. The rates of involvement of the supraglottis and subglottis were 71.4% and 14.8%, respectively, via the AVC. The involvement of the superficial layer of the unilateral or bilateral vocal cords without involvement of the vocal muscle in the AVC region (IVM) or the cartilage was present in 15 cases (48.4%). The involvement of the superficial layer of the unilateral and bilateral vocal cords occurred in 16 cases (51.6%) with the IVM in 13 cases and the involvement of the intermediate lamina of the thyroid cartilage (ITC) in 8 cases. The involvement of the ITC was associated with the involvement of the vocal muscle of the AVC region (P

Incremental updating of frequent item-sets on a database includes three problems. In this paper, these problems are explored when database stores massive data. The main contributions include: (a) introduces the concept of Interesting Support Threshold; (b) proposes Frequent Item-sets Tree (FITr) with compact structure; (c) proposes and implements algorithm FIIU for frequent item-sets incremental updating; (d) in order to further improve performance, proposes the algorithm DFIIU for distributed incremental updating of frequent Item-sets on massive database; (e) gives extensive experiments to show that FIIU and DFIIU algorithms have better performance than traditional algorithm on massive database when the number of items is less.

Recent developments in information technology (IT) have resulted in the collection of a vast amount of customer-specific data. As IT advances, the quality of such information improves. We analyze a unifying spatial price discrimination model that encompasses the two most studied paradigms of two-group and perfect discrimination as special cases. Firms use the available information to classify the consumers into different groups. The number of identifiable consumer segments increases with the information quality. Among our findings (1) when the information quality is low, unilateral commitments not to price discriminate arise in equilibrium; (2) after a unique threshold of information precision such a commitment is a dominated strategy, and the game becomes a prisoners' dilemma; and (3) equilibrium profits exhibit a U-shaped relationship with the information quality.