Factor analysis or sometimes referred to as variable analysis has been extensively used in classification problems for identifying specific factors that are significant to particular classes. This type of analysis has been widely used in application such as customer segmentation, medical research, network traffic, image, and video classification. Today, factor analysis is prominently being used in fault diagnosis of machines to identify the significant factors and to study the root cause of a specific machine fault. The advantage of performing factor analysis in machine maintenance is to perform prescriptive analysis (helps answer what actions to take?) and preemptive analysis (helps answer how to eliminate the failure mode?). In this paper, a real case of an industrial rotating machine was considered where vibration and ambient temperature data was collected for monitoring the health of the machine. Gaussian mixture model-based clustering was used to cluster the data into significant groups, and spectrum analysis was used to diagnose each cluster to a specific state of the machine. The significant features that attribute to a particular mode of the machine were identified by using the random forest classification model. The significant features for specific modes of the machine were used to conclude that the clusters generated are distinct and have a unique set of significant features.

Predictive maintenance and condition-based monitoring systems have seen significant prominence in recent years to minimize the impact of machine downtime on production and its costs. Predictive maintenance involves using concepts of data mining, statistics, and machine learning to build models that are capable of performing early fault detection, diagnosing the faults and predicting the time to failure. Fault diagnosis has been one of the core areas where the actual failure mode of the machine is identified. In fluctuating environments such as manufacturing, clustering techniques have proved to be more reliable compared to supervised learning methods. One of the fundamental challenges of clustering is developing a test hypothesis and choosing an appropriate statistical test for hypothesis testing. Most statistical analyses use some underlying assumptions of the data which most real-world data is incapable of satisfying those assumptions. This paper is dedicated to overcoming the following challenge by developing a test hypothesis for fault diagnosis application using clustering technique and performing PERMANOVA test for hypothesis testing.

The area of predictive maintenance has taken a lot of prominence in the last couple of years due to various reasons. With new algorithms and methodologies growing across different learning methods, it has remained a challenge for industries to adopt which method is fit, robust and provide most accurate detection. Fault detection is one of the critical components of predictive maintenance; it is very much needed for industries to detect faults early and accurately. In a production environment, to minimize the cost of maintenance, sometimes it is required to build a model with minimal or no historical data. In such cases, unsupervised learning would be a better option model building. In this paper, we have chosen a simple vibration data collected from an exhaust fan, and have fit different unsupervised learning algorithms such as PCA T-2 statistic, Hierarchical clustering, K-Means, Fuzzy C-Means clustering and model-based clustering to test its accuracy, performance, and robustness. In the end, we have proposed a methodology to benchmark different algorithms and choosing the final model.

Manufacturing industries have been on a steady path considering for new methods to achieve near-zero downtime to have flexibility in the manufacturing process and being economical. In the last decade with the availability of industrial internet of things (IIoT) devices, this has made it possible to monitor the machine continuously using wireless sensors, assess the degradation and predict the failures of time. Condition-based predictive maintenance has made a significant influence in monitoring the asset and predicting the failure of time. This has minimized the impact on production, quality, and maintenance cost. Numerous approaches have been in proposed over the years and implemented in supervised learning. In this paper, challenges of supervised learning such as need for historical data and incapable of classifying new faults accurately will be overcome with a new methodology using unsupervised learning for rapid implementation of predictive maintenance activity which includes fault prediction and fault class detection for known and unknown faults using density estimation via Gaussian Mixture Model Clustering and K-means algorithm and compare their results with a real case vibration data.

A modified rank order clustering (MROC) method based on weight and data reorganization has been developed to facilitate the needs of real world manufacturing environment. MROC is designed to optimize the manufacturing process based on important independent variables with weights and reorganize the machine-component data that helps form cells where each cell would have approximately the same work load. The developed algorithm using a heuristics minimizes number of bottlenecks for the cellular solution without human input (necessary in King {1980)), while ensuring comparable machine utilizations in each cell. This paper describes our proposed algorithm and a solution to the machine cell design process for the real world manufacturing environment.

The most severe bile duct injuries, also known as complex bile duct injuries (BDI), are associated with significant morbidity and mortality. Although reconstructive biliary surgery is considered standard treatment for complex BDI, recent studies have suggested that an endoscopic or combined endoscopic/percutaneous approach might be an alternative to a surgical approach in selected patients. We report our experience with a variety of endoscopic or combined endoscopic/percutaneous techniques to re-establish biliary drainage in patients with complex BDI and biliary exclusion.

The IEEE802.3an 10GBase-T standard [1] provides full duplex transmission and reception over 4 twisted pairs in a 100M UTP cable. Earlier AFE implementations for this standard have utilized a transmitter hybrid configuration requiring multiple DACs with stringent inter-DAC matching requirements [2-3]. This paper describes a new AFE architecture using a single DAC and line-driver to achieve better echo-cancellation linearity. The design achieves >;59dB TX SFDR and >;68dB echo-cancellation (EC) SFDR across 400MHz bandwidth. The AFE receiver circuitry consists of PGA and 2× time-interleaved SHA-less 11b pipelined ADC operating at 800MS/s. Measured receive noise floor and SFDR is <;-144dBm/Hz and >;53dB, respectively. The AFE dissipates less than 2W power, occupies 17mm2 silicon area including 4 lanes with clocking circuitry, and is implemented in a 40nm triple-gate 0.9V/1.2V/2.5V CMOS process.

Endoscopic treatment is recommended as initial treatment of iatrogenic biliary fistula or strictures. However in complete transection of the bile ducts surgical treatment is indicated due to the inability to visualise the proximal severed end of the bile duct and to cross it via endoscopic means. To review the techniques, complications and outcomes of 6 patients who had undergone successful non surgical treatment of complete transection of the bile ducts. From 1998 till 2010 six patients at a single center underwent non surgical treatment of complete transection of the bile duct. We describe 3 different techniques used to pass a guide wire percutaneously through the intrahepatic bile ducts (IHBD) into the common bile duct (CBD) as well as the complications of these procedures and their outcomes. The first method used a TIPSS (Transjugular Intrahepatic Portosystemic Shunt) set. A 5F catheter mounted in a 10F curved sheath (TIPSS-200 set) was passed percutaneously over a wire into the intrahepatic ducts. The inferior biliary stump was distended by injection of contrast medium using a balloon catheter. The TIPPS needle and 5F catheter were placed under fluoroscopy through the transection into the biliary stump. A wire was then passed into the duodenal lumen and pulled back up through the endoscope. The second method involved passing a guide wire percutaneously into a biloma via the intrahepatic ducts. The guide wire was subsequently retrieved endoscopically through the CBD via a polypectomy snare which was passed into the biloma. The third method used a soehendra stent retriever to tunnel through a narrow communication between the CBD and the IHBD which was delineated using percutaneous cholangiography. A wire was then passed through percutaneously into the duodenum. Subsequent placement of an 8.5 Ring catheter over the wire for biliary drainage was done for all 3 methods. One of 6 patients had an immediate complication of bile leak which resolved with bile duct stenting. All 6 patients had a significant stenosis at the site of transection which required stenting. Four of 6 patients had complete resolution of stenosis after a mean duration of 17.3 months (range 12-26). Out of the 4 patients with resolution of stenosis, 2 had recurrence of stenosis at 4 and 10 years. There were no other complications that resulted in further surgery or mortality in all 6 patients. Non-surgical treatment of transected bile ducts is a feasible option in patients not suitable for surgery. Stricture at the transected end of the bile duct is the most common complication. Further studies are required to define the long term safety and success rates of these new approaches.

AIM:To investigate the potential benefit of Fujinon intelligent chromo endoscopy (FICE)-assisted small bowel capsule endoscopy (SBCE) for detection and characterization of small bowel lesions in patients with obscure gastroenterology bleeding (OGIB).METHODS:The SBCE examinations (Pillcam SB2, Given Imaging Ltd) were retrospectively analyzed by two GI fellows (observers) with and without FICE enhancement. Randomization was such that a fellow did not assess the same examination with and without FICE enhancement. The senior consultant described findings as P0, P1 and P2 lesions (non-pathological, intermediate bleed potential, high bleed potential), which were considered as reference findings.MAIN OUTCOME MEASUREMENTS:Inter-observer correlation was calculated using kappa statistics. Sensitivity and specificity for P2 lesions was calculated for FICE and white light SBCE.RESULTS:In 60 patients, the intra-class kappa correlations between the observers and reference findings were 0.88 and 0.92 (P2), 0.61 and 0.79 (P1), for SBCE using FICE and white light, respectively. Overall 157 lesions were diagnosed using FICE as compared to 114 with white light SBCE (P = 0.15). For P2 lesions, the sensitivity was 94% vs 97% and specificity was 95% vs 96% for FICE and white light, respectively. Five (P2 lesions) out of 55 arterio-venous malformations could be better characterized by FICE as compared to white light SBCE. Significantly more P0 lesions were diagnosed when FICE was used as compared to white light (39 vs 8, P < 0.001).CONCLUSION:FICE was not better than white light for diagnosing and characterizing significant lesions on SBCE for OGIB. FICE detected significantly more non-pathological lesions. Nevertheless, some vascular lesions could be more accurately characterized with FICE as compared to white light SBCE.

were successfully performed.Conclusion: This real-time 3D CT guidance system enhances orientation, navigation, and organ identification during transesophageal NOTES in the human cadaver model.This technology augments the endoscopic view by providing spatial orientation to the operator, which is critical in navigating mediastinal and thoracic anatomy.

AIM:To evaluate the influence of preoperative biliary drainage on morbidity and mortality after surgical resection for ampullary carcinoma.METHODS:We analyzed retrospectively data for 82 patients who underwent potentially curative surgery for ampullary carcinoma between September 1993 and July 2007 at the Singapore General Hospital, a tertiary referral hospital. Diagnosis of ampullary carcinoma was confirmed histologically. Thirty-five patients underwent preoperative biliary drainage (PBD group), and 47 were not drained (non-PBD group). The mode of biliary drainage was endoscopic retrograde cholangiopancreatography (n = 33) or percutaneous biliary drainage (n = 2). The following parameters were analyzed: wound infection, intra-abdominal abscess, intra-abdominal or gastrointestinal bleeding, septicemia, biliary or pancreatic leakage, pancreatitis, gastroparesis, and re-operation rate. Mortality was assessed at 30 d (hospital mortality) and also long-term. The statistical endpoint of this study was patient survival after surgery.RESULTS:The groups were well matched for demographic criteria, clinical presentation and operative characteristics, except for lower hemoglobin in the non-PBD group (10.9 +/- 1.6 vs 11.8 +/- 1.6 in the PBD group). Of the parameters assessing postoperative morbidity, incidence of wound infection was significantly less in the PBD than the non-PBD group [1 (2.9%) vs 12 (25.5%)]. However, the rest of the parameters did not differ significantly between the groups, i.e. sepsis [10 (28.6%) vs 14 (29.8%)], intra-abdominal bleeding [1 (2.9%) vs 5 (10.6%)], intra-abdominal abscess [1 (2.9%) vs 8 (17%)], gastrointestinal bleeding [3 (8.6%) vs 5 (10.6%)], pancreatic leakage [2 (5.7%) vs 3 (6.4%)], biliary leakage [2 (5.7%) vs 3 (6.4%)], pancreatitis [2 (5.7%) vs 2 (4.3%)], gastroparesis [6 (17.1%) vs 10 (21.3%)], need for blood transfusion [10 (28.6%) vs 17 (36.2%)] and re-operation rate [1 (2.9%) vs 5 (10.6%)]. There was no early mortality in either group. Median survival was 44 mo (95% CI: 34.2-53.8) in the PBD group and 41 mo (95% CI: 27.7-54.3; P = 0.86) in the non-PBD group.CONCLUSION:Biliary drainage before surgery for ampullary cancer significantly reduced postoperative wound infection. Overall mortality was not influenced by preoperative drainage.

Background: Diagnostic accuracy of EUS for choledocholithiasis compares favorably with that of ERCP. EUS is less invasive and expensive than ERCP. There is dearth of data from Asia in this regard. Aims: To assess the incidence of choledocholithiasis in low to moderate risk patients by endoscopic ultrasound (EUS), and to ascertain clinical and economic benefits of EUS by avoidance of unnecessary endoscopic retrograde cholangiography (ERC) and sphincterotomy (EST). Methods: We analyzed a prospective series of 221 patients (88 men, 133 women; mean age 62 years, range 22-95 years) who underwent EUS for detecting choledocholithiasis from May 2005 till May 2007 at a tertiary referral center and a teaching hospital. Based on clinical, biochemical, and cross-sectional imaging data (US or CT) patients were stratified into low and moderate risk groups. Patients with normal sized CBD with or without biochemical derangement were included in the low risk group (128). Patients with dilated CBD (>7 mm) were included in the moderate risk group (93). High risk patients were excluded. Positive EUS findings were confirmed by ERCP or by surgery; negative findings were confirmed by clinical follow-up. EUS result was considered a true negative if the patient was confirmed symptom-free with normal tests on follow-up of 6 months. The costs of EUS (procedure, days of hospitalization, any morbidity) were compared with the estimated costs of the ERCP procedures avoided in patients with true-negative EUS findings. Results: EUS findings were verified in 221 patients: EUS was positive for choledocholithiasis in 65 patients (29.4%) and negative in 156 patients (70.6%). Choledocholithiasis was detected in 25 patients (19.5%) in the low risk group and 40 patients in the moderate risk group (43%). By ERCP (64 patients), surgical bile duct exploration (1), and follow-up (156), EUS diagnoses were confirmed as follows: true positive (65), true negative (152), false positive (0), and false negative (1); sensitivity (97.8%), specificity (99.7%), positive predictive value (99%), negative predictive value (99%). Three patients were lost to follow up. The mean stone size was 4.5 mm (+/− 1.87). In 156 (70.6%) patients, more invasive investigations of the bile duct were avoided. The mean cost for patients managed by the EUS-based strategy was US$ 795.2 (+/−238). This was significantly less than the theoretical mean cost of US$ 1630.5 (p < 0.01) for ERCP. Conclusions: The results of this study confirm that EUS is highly reliable for the diagnosis of choledocholithiasis. Its use offers considerable clinical and economic advantages by preventing inappropriate ERCP.

The coating of transparent ZnO films using zinc 2-ethylhexanoate [Zn(OOCH(C2H5)C4H9)2] as a novel metal organic monomer is reported. Zinc 2-ethylhexanoate is liquid at room temperature and can be spin-coated on a flat substrate without precipitation of ZnO under ambient condition. The spin-coated films were heated at different temperatures to remove unwanted organic materials from the surface. It was found that transparent ZnO films could be produced on glass substrates at low heating temperature (~400 °C). The ZnO films produced using the new monomer were free of cracks and defects. Also the ZnO films produced using the new monomer have excellent optical transmittance, mechanical properties and small surface roughness. The surface morphology and degree of crystallinity of the films coated by the new monomer were compared with these properties of ZnO films produced using zinc acetate-based sol–gels. The results clearly indicate that the novel monomer is a potential precursor for coating transparent ZnO films at low temperatures.

Nanocrystalline cobalt oxide thin films were fabricated by sol–gel processing method. The effect of cobalt salt amount in sol–gel mixture on film properties was investigated by means of Raman spectroscopy and atomic force microscopy. Micropatterns of these sol–gel mixtures were fabricated by spin coating followed by a lift-off method. It is generally known that sol–gel processed films are difficult to etch or remove by chemical and plasma techniques. In this novel process, cobalt oxide microstructures could be fabricated by transformation of pre-fabricated nanocrystalline cobalt oxide particles in a sol–gel process. Also, the growth of carbon nanotubes on fabricated cobalt oxide films was investigated. It was found that different size multiwall carbon nanotubes could be grown on the cobalt oxide films depending on the concentration of cobalt salt in sol–gel mixtures.

Mortars and concretes are formulated from hydraulic binders, and are adapted for more rapid setting and hardening in cold weather, such formulations including the admixture of hydraulic binder, aggregates and water, and such formulations being characterized in that they include: (a) a water-soluble dispersant/water-reducing agent; (b) an inorganic basic agent selected from the group comprising the hydroxides of alkali metals other than lithium, alkaline earth metal hydroxides and the mixtures of one of such hydroxides with lithium hydroxide; and (c) a water-soluble salt of an inorganic oxyacid or an aliphatic or aromatic carboxylic acid, said acid having an ionization constant pKa of less than 2.5 in water at 25 DEG C.

This paper describes the fabrication of fine-grained nanocrystalline tungsten oxide thin films for gas sensor application. Thin films of WO3 Were prepared by thermal evaporation of metallic tungsten oxide powder followed by thermal annealing. The films were annealed at different temperatures to form semiconducting WO3 films suitable for gas sensor and other electronic device applications. It was found that 300 degreesC annealed film has a uniformly formed nanocrystalline structure compared with high temperature annealed samples. When these nanocrystalline films were re-annealed at high temperature, the crystallinity and the surface morphology were remained unchanged. In this paper, the structural and Surface characteristics of WO3 films are described as a function of annealing treatments.