Miracle-dz/UniFAR-FTUs huggingface dataset:
Topological insulators and Mott physics from the Hubbard interaction

We investigate the Hubbard model on the honeycomb lattice with intrinsic spin orbit interactions as a paradigm for two-dimensional topological band insulators in the presence of interactions. Applying a combination of Hartree-Fock theory, slave-rotor techniques, and topological arguments, we show that the topological band insulating phase persists up to quite strong interactions. Then we apply the slave-rotor mean-field theory and find a Mott transition at which the charge degrees of freedom become localized on the lattice sites. The spin degrees of freedom, however, are still described by the original Kane-Mele band structure. Gauge field effects in this region play an important role. When the honeycomb layer is isolated then the spin sector becomes already unstable toward an easy plane Neel order. In contrast, if the honeycomb lattice is surrounded by extra "screening" layers with gapless spinons, then the system will support a fractionalized topological insulator phase with gapless spinons at the edges. For large interactions, we derive an effective spin Hamiltonian.
Perioperative chemotherapy versus postoperative chemoradiotherapy in patients with resectable gastric/gastroesophageal junction adenocarcinomas: A survival analysis of 5058 patients

Both perioperative chemotherapy (PECT) and postoperative chemoradiotherapy (POCRT) have a significant survival advantage over surgery alone for the treatment of patients with gastric cancer. However, to the best of our knowledge, these regimens have not been compared in a randomized clinical trial. The purpose of the current observational study was to compare overall survival among patients receiving PECT versus POCRT for the treatment of gastric/gastroesophageal junction (GEJ) adenocarcinomas.
Visual Representation: Implications for Decision Making

A large number of visualization tools have been created to help decision makers understand increasingly rich databases of product, customer, sales force, and other types of marketing information. This article presents a framework for thinking about how visual representations are likely to affect the decision processes or tasks that marketing managers and consumers commonly face, particularly those that involve the analysis or synthesis of substantial amounts of data. From this framework, the authors derive a set of testable propositions that serve as an agenda for further research. Although visual representations are likely to improve marketing manager efficiency, offer new insights, and increase customer satisfaction and loyalty, they may also bias decisions by focusing attention on a limited set of alternatives, increasing the salience and evaluability of less diagnostic information, and encouraging inaccurate comparisons. Given this, marketing managers are advised to subject insights from visual representations to more formal analysis.
Intended Use of Proceeds and the Post-Issue Operating Performance of IPO Firms: A Quantile Regression Approach

This paper investigates the link between intended use of proceeds and the decline in post-issue operating performance of IPO firms. After taking into account special features of the compositional data containing zero values, a quantile regression analysis is employed for the Indonesian equity market data over the period of 2000-2010. The results show that the post-issue performance can be explained by different types of intended use of proceeds. Fixed asset investment and investment in stock market shares will lead to better operating performance for average and high performing firms only. Allocation to other usages leads to poor operating performance. The findings were found to be robust when ownership structure was included in the models. These results have policy implications for the management of IPO proceeds.
UDC: a self-adaptive uneven clustering protocol for dynamic sensor networks

The constrained resources of sensor networks challenge researchers to design resource efficient protocols. Clustering protocols are efficient to support the aggregation queries in sensor databases. This paper presents a novel clustering protocol, named UDC ( spatially Uneven Density Clustering ), to prolong the lifetime of sensor networks. Unlike other clustering protocols, UDC forms distributed sensor nodes into spatially uneven clusters according to local network conditions. In short, clustered by UDC, the nodes nearby the central base are grouped into smaller clusters, while the distant nodes are clustered into larger groups to save resources. Our simulation results exemplify that UDC can extend the lifetime of sensor networks up to twice as long as the other clustering protocols do.
Comparative Study of the Plaque Removal Efficacy of Three Types of Toothbrushes in Patients with Fixed Orthodontic Appliances

Introduction: Patients undergoing orthodontic treatment with fixed appliances have a challenging oral hygiene situation because brackets tenaciously trap food and other oral debris. Good plaque control is an important factor in the maintenance of dental health during fixed appliance therapy. Many different types of specially designed toothbrushes have been developed in recent years in order to improve the plaque removal. One of these new developments is a manual triple headed brush which is called 'superbrush' which is intended to clean the oral, buccal and occlusal surfaces of the teeth at one time. A clinical study was planned to evaluate the effectiveness of plaque removal by using the new triple headed toothbrush compared to the conventional manual toothbrush and an orthodontic toothbrush. Methods: A total of 75 patients, aged between 18 and 28 years, were equally divided into three groups: Group I (triple headed toothbrush), group II (orthodontic toothbrush) and group III (conventional toothbrush). The gingival index (Loe and Silness, 1963) and plaque index (Turesky Gilmore and Glickman, 1962) were recorded at baseline, month 1, month 2, month 3 and month 4, and results were subjected to statistical analysis utilizing ANOVA one way and multiple comparison Tukey’s HSD test. Results: Comparison of the mean gingival and plaque index scores and difference in mean plaque scores between the groups was done and found to be statistically significant (p < 0.05). Conclusion: The study indicated that the triple headed toothbrush was more efficient in reduction of plaque scores and improvement in gingival index scores overall, and more effective in removal of plaque from tooth surfaces compared to the other two toothbrushes.
Investment Behavior and Risk Dynamics: Evidence from Share Repurchases

We explore the distinguishing characteristics of firms that completed or stopped their repurchase programs. Our findings help further understanding the economic reasons why firms would stop buybacks. Based on our international sample of 818 completed and 101 stopped share repurchase programs shows a significant drop in systematic risk around completed buybacks. This suggests that completed buybacks are a response to deteriorating investment opportunities. In contrast, the systematic risk of incomplete-repurchasing firms decreases prior to the announcement, followed by an increase that peaks during the event period. This suggests that firms stop their repurchase intentions when growth options move into the money.
Prophylactic Inferior Vena Cava Filters Prevent Pulmonary Embolisms in High-Risk Patients Undergoing Major Spinal Surgery

Study Design Clinical case series. Objective To show the efficacy of prophylactic inferior vena cava (IVC) filters in preventing venous thromboembolic event (VTE) in high-risk patients undergoing major spinal surgery. Summary of Background Data Patients undergoing major spinal surgery are at increased risk for VTEs. Recent studies have shown IVC filters are effective in preventing clinically significant pulmonary embolism (PE), but have not documented the frequency of all emboli prevented. Methods Patients undergoing major spinal surgery from 2006 to 2009, having IVC filters placed for VTE prophylaxis, were reviewed. Patients with 2 or more risk factors for VTE were included and their perioperative courses were reviewed for PE and device-related complications. Cavograms obtained at the time of attempted filter retrieval identified intercepted emboli. The rates of intercepted emboli and clinical PEs were compared with those of similar populations undergoing similar procedures. Results Approximately 17% of patients had entrapped thrombus present at attempted filter retrieval. An additional 17% of filters were unable to be retrieved due to change in position within the IVC. No patients experienced symptomatic PE. One patient developed a deep vein thrombus requiring pharmacologic treatment and another patient developed superficial phlebitis. There were no complications related to IVC filter use. Conclusions These findings show that the decreased rate of PE observed in this and other series is likely because of the use of IVC filters, rather than sampling bias inherent when studying a relatively rare problem. The safety of IVC filters in this population is also confirmed. The observed rate of clinical PE is consistent with other published series. Emboli intercepted by filters may more accurately estimate clinically significant emboli prevented. Therefore, cavograms may prove to be a valuable method of assessing the efficacy of these devices in future studies.
Sales Force Automation Systems and Sales Force Productivity

Abstract Salespeople are in a unique position of being in very close proximity to customers and thus have the ability to create and maintain long-term relationships with them. Sales force automation systems (SFA) have the ability to help or hinder this relationship building process. This article looks at SFA and its impact on sales force productivity. Much of the current research in the area of SFA seems to focus on efficiency issues within the firm, with particular attention being paid to technology implementation and reasons for high SFA failure rates. The authors review past literature and identify potential areas for future research by creating and presenting a research agenda. Many of the future research areas lie in the realm of effectiveness of SFA rather than the efficiency side of SFA. Although efficiency is still of great importance to SFA researchers and practitioners, the customer or relationship focus of SFA effectiveness is also needed.
Pyomyositis caused by methicillin-resistant Staphylococcus aureus.

To the Editor: Pyomyositis is common in tropical regions but is rarely reported in temperate climates. In the United States, most cases are associated with human immunodeficiency virus infection or other immunosuppressive conditions, including diabetes mellitus, cancer, connective-tissue diseases, and cirrhosis.1 Christin and Sarosi observed that Staphylococcus aureus was the causative organism in 70 percent of cases, and that 31 percent of the patients had bacteremia.2 We describe four patients with community-acquired pyomyositis caused by methicillin-resistant S. aureus who presented to our hospital within a span of six months. Patient 1 was a 22-year-old Nicaraguan woman without previous medical problems .
CEO compensation as a mechanism to induce firm performance

Over the past few decades, academic literature, specifically on agency theory and executive compensation, has argued that CEO compensation should be aligned to firm performance in order to increase shareholder value. Nevertheless, some studies present the contrary idea, in which no link between performance and compensation can be established. This thesis analyses the relationship between firm performance and CEO compensation regarding Portuguese listed firms in the period of 2008-2013. No statistical evidence was found linking firm performance and CEO compensation, even after introducing governance and financial control variables as well as performing small sampling analysis of the top performers.
Selective biodegradation of keratin matrix in feather rachis reveals classic bioengineering

Flight necessitates that the feather rachis is extremely tough and light. Yet, the crucial filamentous hierarchy of the rachis is unknown—study hindered by the tight chemical bonding between the filaments and matrix. We used novel microbial biodegradation to delineate the fibres of the rachidial cortex in situ. It revealed the thickest keratin filaments known to date (factor >10), approximately 6 µm thick, extending predominantly axially but with a small outer circumferential component. Near-periodic thickened nodes of the fibres are staggered with those in adjacent fibres in two- and three-dimensional planes, creating a fibre–matrix texture with high attributes for crack stopping and resistance to transverse cutting. Close association of the fibre layer with the underlying ‘spongy’ medulloid pith indicates the potential for higher buckling loads and greater elastic recoil. Strikingly, the fibres are similar in dimensions and form to the free filaments of the feather vane and plumulaceous and embryonic down, the syncitial barbules, but, identified for the first time in 140+ years of study in a new location—as a major structural component of the rachis. Early in feather evolution, syncitial barbules were consolidated in a robust central rachis, definitively characterizing the avian lineage of keratin.
Strategic Alliances between SMEs and Large Firms: An Exploration of the Dynamic Process

This paper explores the dynamics in strategic alliances between small and medium sized enterprises (SMEs) and large organisations (corporates). Despite the volumes written on this subject, few studies take into account this context of inter-organisational relationships. The dynamics in strategic partnerships between small and large organisations are potentially multifaceted and fraught with complexities and contradictions. The partner organisations bring diverse interests and resources to the strategic partnerships and these affect the dynamics of their relationships. Using the literature on strategic alliances, this article examines four such strategic partnerships in New Zealand. Results show that in order to increase the likelihood of successful collaboration, the alliance partners must understand the importance of building trust and a shared alliance purpose, and both of these must be communicated effectively at executive and operational levels.
Embedding Factorization Models for Jointly Recommending Items and User Generated Lists

Existing recommender algorithms mainly focused on recommending individual items by utilizing user-item interactions. However, little attention has been paid to recommend user generated lists (e.g., playlists and booklists). On one hand, user generated lists contain rich signal about item co-occurrence, as items within a list are usually gathered based on a specific theme. On the other hand, a user's preference over a list also indicate her preference over items within the list. We believe that 1) if the rich relevance signal within user generated lists can be properly leveraged, an enhanced recommendation for individual items can be provided, and 2) if user-item and user-list interactions are properly utilized, and the relationship between a list and its contained items is discovered, the performance of user-item and user-list recommendations can be mutually reinforced. Towards this end, we devise embedding factorization models, which extend traditional factorization method by incorporating item-item (item-item-list) co-occurrence with embedding-based algorithms. Specifically, we employ factorization model to capture users' preferences over items and lists, and utilize embedding-based models to discover the co-occurrence information among items and lists. The gap between the two types of models is bridged by sharing items' latent factors. Remarkably, our proposed framework is capable of solving the new-item cold-start problem, where items have never been consumed by users but exist in user generated lists. Overall performance comparisons and micro-level analyses demonstrate the promising performance of our proposed approaches.
Report of the Workshop on Semantic Heterogeneity and Interpolation in multidatabase Systems

This report presents a review of the problems that were discussed during the Workshop on Semantic Heterogeneity and Interoperability in Multidatabase Systems. The workshop participants discussed the importance of interoperation in the U S WEST information processing environment and the progress that has been achieved in three major research areas: resolution of semantic heterogeneity among cooperating heterogeneous systems, transaction management in such environments, and software architecture for interoperation. The workshop provided researchers with necessary feedback from the industrial perspective and helped in identifying the major issues that need further research. The following problems concerning the applicability of the methods proposed for data processing in the heterogeneous, autonomous information systems have been identified: (i) many of the assumptions made in the research community are too restrictive to make the results directly applicable to existing environments; (ii) performance ramifications of various heterogeneous architectures need to be understood; (iii) the prototype systems need to be put to the test with real data, schemas, and transaction streams to verify their utility.
Vertical and Venereal transmission of Chandipura Virus (Rhabdoviridae) by Aedes aegypti (Diptera: Culicidae)

Abstract Experiments in the laboratory documented vertical and venereal transmission of Chandipura virus (CHPV) in Aedes aegypti (L.). The minimum filial infection rate among the progeny of infected females was 1.2%; the rate among male and female progeny was 0.9 and 1.4%, respectively. The venereal infection rate of CHPV among inseminated females was 32.7%. Our study indicates the possible occurrence of vertical and venereal transmission of CHPV in insect vectors.
Object Fingerprinting

ii Acknowledgements. iv Introduction . 1 1.1 Object Fingerprinting. 1 1.2 Earlier Work. 2 1.3 Research Questions. 2 1.4 Structure of this thesis . 2 Methods . 3 2.1 Scale Invariant Feature Transform (SIFT). 3 2.1.1 Scale Space . 3 2.1.2 Descriptor . 4 2.1.3 Matching . 4 2.2 HueSatSIFT . 5 2.2.1 Hue and Saturation . 5 2.2.2 Descriptor . 6 2.3 Colour Invariant SIFT . 6 2.3. 1 Colour Invariance . 6 2.3. 2 Invariant Descriptor. 7 2.4 PCA-SIFT. 8 2.4.1 Principal Components Analysis . 8 2.4.2 Descriptor . 8 2.5 Bag of Visual Words. 9 2.6 Spatial Pyramid Matching. 11 2.7 Colour Co-occurrence Histograms . 12 2.8 Cortex-Like Mechanisms. 13 2.9 Boosting . 15 2.9. 1 Multiclass Boosting . 15 2.10 Feature Ensemble . 17 Data . 18 Results . 22 4.1 SIFT . 22 4.2 HueSatSIFT . 24 4.3 Colour Invariant SIFT . 25 4.4 PCA-SIFT. 27 4.5 Bag of Visual Words. 28 4.6 Spatial Pyramid Matching. 30 4.7 Colour Co-occurrence Histograms . 34 4.9 Boosting . 36 4.10 Feature Ensemble . 39 Conclusion and future work. 41 References . 43
Bond covenants, bond issue size, and credit default spered premiums

My dissertation contains two essays. It discusses the role of bond covenants in modern capital market and how they impact firms’ financial activities. Bond covenants are effective mechanism to mitigate the agency problems between bondholders and bond issuers. The design of bond covenants has extensive influence on firms’ financial activities. The first essay examines the effect of bond covenants on issue size. The agency problems can prevent bondholders from lending fund to issuers. The inclusion of bond covenants in indenture can provide bondholder with protection by restricting issuers’ activities, indicating the potential relationship between bond issue size and covenants. My findings suggest that restrictiveness of bond covenants is positively related with the issue size. Due to different agency problem, the design of bond covenant put emphasis on different restriction covenant. As a result, the essay observes that for investment grade (below grade) issuers issue size is positively related with the restrictiveness of financing (investment) covenants. Meanwhile due to the severe agency problem in low quality issuers, low rating firms have to include more covenants to raise the same amount of capital. The findings in the first essay indicate that firms can sacrifice their management by including restrictive covenants to raise more capital. The second essay examines the effect of bond covenants on likelihood of CDS issuance and the level of CDS spreads. Like bond covenants, CDS contracts are also effective mechanism to mitigate the agency problem between bondholders and bond issuers. The issuance of CDS occurs after firms include bond covenants, indicating that one of reasons for CDS is bondholders’ feeling of insecurity due to the unrestrictive bond covenants. My findings indicate that the restrictiveness of bond covenant can affect the likelihood of CDS issuance. CDS serves as complement to bond covenants for investment grade bondholder to mitigate the agency problem by providing bondholder with extra protection in the case of default. At the same time, bond covenant can also influence the level of CDS spreads by influencing the issuers’ default risk because actual use of bond covenants can lower the default risk. My findings suggest the level of CDS spread is negatively related with the restrictiveness of bond covenants. The findings in essay 2 not only provide possible reasons for CDS issuance and an important factor influencing the level of CDS spread but also build a link between literature of bond covenants and CDS.
Human Resource Management, Service Quality, and Economic Performance in Call Centers

This paper examines the relationship between human resource practices, operational outcomes, and economic performance in call centers. The study draws on a sample of 64 call centers serving the mass market in a large telecommunications services company. Surveys of 1,243 employees in the 64 centers were aggregated to the call center level and matched to archival data on service process quality, as measured by customer surveys; call handling time, revenues per call, and net revenues per call. Our path analysis shows that human resource practices emphasizing employee training, discretion, and rewards lead to higher service quality, higher revenues per call, and higher net revenues per call. In addition, service quality mediates the relationship between human resource practices and these economic outcomes. There is no significant relationship between HR practices and labor efficiency, as measured by call handling time; and labor efficiency is inversely related to revenue generation.