Energy-Based Accounting and Scheduling of Virtual Machines in a Cloud System

Computer systems & NetworksVirtualization enables flexible resource provisioning and improves energy efficiency through consolidating virtualized servers into a smaller number of physical servers than that of the virtualized servers. Therefore, it is becoming an essential component for the emerging cloud computing model. Currently, virtualized environment including cloud computing systems bills users for the amount of their processor time, or the number of their virtual machine instances. However, accounting based only on the depreciation cost of server hardware is not an economically proper model because the cooling and energy cost for datacenters has already exceeded the cost to own servers. This paper suggests an estimation model to account energy consumption of each virtual machine without any dedicated measurement hardware. Our estimation model estimates the energy consumption of a virtual machine based on the in-processor events generated by the virtual machine. Based on the estimation model, this paper also proposes the virtual machine scheduling algorithm that is able to provide computing resources according to the energy budget of each virtual machine. The suggested schemes are implemented in the Xen virtualization system, and the evaluation shows the suggested schemes estimate and provide energy consumption with errors less than 5% of the total energy consumption.ope

A survey of experience-based preference of Nickel- Titanium rotary files and incidence of fracture among general dentists

Objectives: The purpose was to investigate the preference and usage technique of NiTi rotary instruments and to retrieve data on the frequency of re-use and the estimated incidence of file separation in the clinical practice among general dentists. Materials and Methods: A survey was disseminated via e-mail and on-site to 673 general dentists. The correlation between the operators experience or preferred technique and frequency of re-use or incidence of file fracture was assessed. Results: A total of 348 dentists (51.7%) responded. The most frequently used NiTi instruments was ProFile (39.8%) followed by ProTaper. The most preferred preparation technique was crowndown (44.6%). 54.3% of the respondents re-used NiTi files more than 10 times. There was a significant correlation between experience with NiTi files and the number of reuses (p = 0.0025). 54.6% of the respondents estimated experiencing file separation less than 5 times per year. The frequency of separation was significantly correlated with the instrumentation technique (p = 0.0003). Conclusions: A large number of general dentists in Korea prefer to re-use NiTi rotary files. As their experience with NiTi files increased, the number of re-uses increased, while the frequency of breakage decreased. Operators who adopt the hybrid technique showed less tendency of separation even with the increased number of re-use.OAIID:oai:osos.snu.ac.kr:snu2012-01/102/0000027976/8SEQ:8PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:0000027976ADJUST_YN:NEMP_ID:A076085DEPT_CD:861FILENAME:RDE37-4(4이우철).pdfDEPT_NM:치의학과EMAIL:[email protected]_YN:NCONFIRM:YCONFIRM:

Antimicrobial effect of calcium hydroxide as an intracanal medicament in root canal treatment: a literature review - Part II. in vivo studies

The first part of this study reviewed the characteristics of calcium hydroxide (Ca(OH)2) and summarized the results of in vitro studies related to its antimicrobial effects. The second part of this review covers in vivo studies including human clinical studies and animal studies. The use of Ca(OH)2 as an intracanal medicament represented better histological results in animal studies. However, human clinical studies showed limited antimicrobial effects that microorganisms were reduced but not eliminated through the treatment, and that some species had resistance to Ca(OH)2. Most of clinical outcome studies supported that there is no improvement in healing of periapical lesions when Ca(OH)2 was applied between appointments. Further studies are required for the antimicrobial effects of Ca(OH)2, and search for the ideal material and technique to completely clean infected root canals should be continued

Antimicrobial effect of calcium hydroxide as an intracanal medicament in root canal treatment: a literature review - Part I. In vitro studies

The goal of endodontic treatment is the prevention and control of pulpal and periradicular infections. Calcium hydroxide (Ca(OH)2) has been widely used in endodontics as an intracanal medicament to eliminate the remaining microorganisms after chemomechanical preparation. The purpose of this article is to review the antimicrobial properties of Ca(OH)2 as an intracanal medicament in root canal treatment. The first part of this review details the characteristics of Ca(OH)2 and summarizes the results of in vitro studies related to its antimicrobial effect. The antimicrobial effect of Ca(OH)2 results from the release of hydroxyl ions when it comes into contact with aqueous fluids. Ca(OH)2 has a wide range of antimicrobial effects against common endodontic pathogens, but is less effective against Enterococcus faecalis and Candida albicans. The addition of vehicles or other agents might contribute to the antimicrobial effect of Ca(OH)2

Cardiovascular effect of epinephrine in endodontic microsurgery: a review

Epinephrine is one of the most widely-used vasoconstrictors in dental treatment including endodontic microsurgery. However, the systemic safety of epinephrine has been in debate for many years because of its potential risk to cause cardiovascular complications. The purpose of this review was to assess the cardiovascular effect of epinephrine use in endodontic microsurgery. Endodontic microsurgery directly applies epinephrine into the bone cavity, and the amount is reported to be much larger than other dental surgeries. Moreover, when considering that systemic potency of intraosseous application is reported to be comparable to intravenous application, the systemic influence of epinephrine could be increased in endodontic microsurgery. Besides, pre-existing cardiovascular complications or drug interactions can enhance its systemic influence, resulting in increased susceptibility to cardiovascular complications. Although clinical studies have not reported significant complications for patients without severe systemic complications, many epinephrine-induced emergency cases are warning the cardiovascular risk related with pre-existing systemic disease or drug interactions. Epinephrine is a dose-sensitive drug, and its hypersensitivity reaction can be fatal to patients when it is related to cardiovascular complications. Therefore, clinicians should recognize the risk, and the usage of pre-operative patient evaluation, dose control and patient monitoring are required to ensure patient's safety during endodontic microsurgery

Anomaly VAE-Transformer: A Deep Learning Approach for Anomaly Detection in Decentralized Finance

DeFi, a decentralized financial service based on blockchain, not only provides innovative financial services, but also poses various risks, such as the Terra Luna crash. Therefore, anomaly detection in DeFi is necessary to ensure the safety and reliability of the DeFi ecosystem. However, this is very difficult because of the complex protocol, interaction among smart contracts, and high market volatility. In this study, we propose a novel method to effectively detect anomalies in DeFi. To the best of our knowledge, this is the first study that utilizes deep learning to detect anomalies in DeFi. We propose a deep learning model, anomaly VAE-Transformer, which combines the variational autoencoder to extract local information in the short term, and the transformer, to identify dependencies between data in the long term. Based on a deep understanding of DeFi protocols, the proposed model collects and analyzes various on-chain data of Olympus DAO, a representative DeFi protocol, for extracting features suitable for anomaly detection. Then, we demonstrate the superiority of the proposed model by analyzing four anomaly cases detected successfully by the proposed model in Olympus DAO. A malicious attack attempt and structural changes in DeFi protocols can be identified quickly using the proposed method; this is expected to help protect the assets of DeFi users and improve the safety, reliability, and transparency of the DeFi market. The dataset and codes are available at https://github.com/fialle/Anomaly-VAE-Transformer</uri

Does apical root resection in endodontic microsurgery jeopardize the prosthodontic prognosis?

Apical surgery cuts off the apical root and the crown-to-root ratio becomes unfavorable. Crown-to-root ratio has been applied to periodontally compromised teeth. Apical root resection is a different matter from periodontal bone loss. The purpose of this paper is to review the validity of crown-to-root ratio in the apically resected teeth. Most roots have conical shape and the root surface area of coronal part is wider than apical part of the same length. Therefore loss of alveolar bone support from apical resection is much less than its linear length.The maximum stress from mastication concentrates on the cervical area and the minimum stress was found on the apical 1/3 area. Therefore apical root resection is not so harmful as periodontal bone loss. Osteotomy for apical resection reduces longitudinal width of the buccal bone and increases the risk of endo-perio communication which leads to failure. Endodontic microsurgery is able to realize 0 degree or shallow bevel and precise length of root resection, and minimize the longitudinal width of osteotomy. The crown-to-root ratio is not valid in evaluating the prosthodontic prognosis of the apically resected teeth. Accurate execution of endodontic microsurgery to preserve the buccal bone is essential to avoid endo-perio communication

Minimizing the extra-oral time in autogeneous tooth transplantation: use of computer-aided rapid prototyping (CARP) as a duplicate model tooth

Objectives The maintenance of the healthy periodontal ligament cells of the root surface of donor tooth and intimate surface contact between the donor tooth and the recipient bone are the key factors for successful tooth transplantation. In order to achieve these purposes, a duplicated donor tooth model can be utilized to reduce the extra-oral time using the computer-aided rapid prototyping (CARP) technique. Materials and Methods Briefly, a three-dimensional digital imaging and communication in medicine (DICOM) image with the real dimensions of the donor tooth was obtained from a computed tomography (CT), and a life-sized resin tooth model was fabricated. Dimensional errors between real tooth, 3D CT image model and CARP model were calculated. And extra-oral time was recorded during the autotransplantation of the teeth. Results The average extra-oral time was 7 min 25 sec with the range of immediate to 25 min in cases which extra-oral root canal treatments were not performed while it was 9 min 15 sec when extra-oral root canal treatments were performed. The average radiographic distance between the root surface and the alveolar bone was 1.17 mm and 1.35 mm at mesial cervix and apex; they were 0.98 mm and 1.26 mm at the distal cervix and apex. When the dimensional errors between real tooth, 3D CT image model and CARP model were measured in cadavers, the average of absolute error was 0.291 mm between real teeth and CARP model. Conclusions These data indicate that CARP may be of value in minimizing the extra-oral time and the gap between the donor tooth and the recipient alveolar bone in tooth transplantation