Excision And Recovery: Visual Defect Obfuscation Based Self-Supervised Anomaly Detection Strategy

Due to scarcity of anomaly situations in the early manufacturing stage, an unsupervised anomaly detection (UAD) approach is widely adopted which only uses normal samples for training. This approach is based on the assumption that the trained UAD model will accurately reconstruct normal patterns but struggles with unseen anomalous patterns. To enhance the UAD performance, reconstruction-by-inpainting based methods have recently been investigated, especially on the masking strategy of suspected defective regions. However, there are still issues to overcome: 1) time-consuming inference due to multiple masking, 2) output inconsistency by random masking strategy, and 3) inaccurate reconstruction of normal patterns when the masked area is large. Motivated by this, we propose a novel reconstruction-by-inpainting method, dubbed Excision And Recovery (EAR), that features single deterministic masking based on the ImageNet pre-trained DINO-ViT and visual obfuscation for hint-providing. Experimental results on the MVTec AD dataset show that deterministic masking by pre-trained attention effectively cuts out suspected defective regions and resolve the aforementioned issues 1 and 2. Also, hint-providing by mosaicing proves to enhance the UAD performance than emptying those regions by binary masking, thereby overcomes issue 3. Our approach achieves a high UAD performance without any change of the neural network structure. Thus, we suggest that EAR be adopted in various manufacturing industries as a practically deployable solution.Comment: 10 pages, 5 figures, 5 table

Special Issue on Research and Enhancement of Mechanical Properties of Cementitious Materials

Concrete is the most-produced product on the planet [...

Special Issue on Research and Enhancement of Mechanical Properties of Cementitious Materials

Concrete is the most-produced product on the planet [...

Dynamic Control of Region of Attraction Using Variable Inductor for Stabilizing DC Microgrids with Constant Power Loads

DC microgrids with power electronic converter units are prone to become unstable due to the well-known negative impedance characteristic of constant power loads. For such systems, the global stability cannot be assumed. It is known that the transient stability of the system can be degraded by large and fast disturbances due to the reduced stability region. As a result, the system gets to operate outside the stability region and becomes unstable even if the steady-state operating point is in the stable region. To overcome this problem, a dynamic stabilizer that controls the stability region using variable inductor is proposed to guarantee stable operation during transient-states. The proposed scheme is straightforward and can be implemented with minimal power consumption. Furthermore, it is robust for parameter variation. The feasibility of the proposed method is verified experimentally

Long-Term Flexural Behaviors of GFRP Reinforced Concrete Beams Exposed to Accelerated Aging Exposure Conditions

This study investigates the impact of accelerated aging conditions on the long-term flexural behavior and ductility of reinforced concrete (RC) members with glass fiber-reinforced polymer (GFRP) bars (RC-GFRP specimen) and steel bars (RC-steel specimen). A total of thirty six specimens were designed with different amounts of reinforcement with three types of reinforcing bars (i.e., helically wrapped GFRP, sand-coated surface GFRP and steel). Eighteen specimens were subjected to sustained loads and accelerated aging conditions (i.e., 47 °C and 80% relative humidity) in a chamber. The flexural behavior of specimens under 300-day exposure was compared to that of the companion specimens without experiencing accelerated aging conditions. Results indicate that the accelerated aging conditions reduced flexural capacity in not only RC-steel, but also RC-GFRP specimens, with different rates of reduction. Different types of GFRP reinforcement exhibited different rates of degradation of the flexural capacity when embedded in concrete under the same exposure conditions. Several existing models were compared with experimental results for predicting the deflection and deformability index for specimens. Bischoff and Gross’s model exhibited an excellent prediction of the time-dependent deflections. Except for the deformability index proposed by Jaeger, there was no general trend related to the aging duration. This study recommends the need for further investigation on the prediction of the deformability index

Modified Graphene Oxide-Incorporated Thin-Film Composite Hollow Fiber Membranes through Interface Polymerization on Hydrophilic Substrate for CO2 Separation

Thin-film composite mixed matrix membranes (CMMMs) were fabricated using interfacial polymerization to achieve high permeance and selectivity for CO2 separation. This study revealed the role of substrate properties on performance, which are not typically considered important. In order to enhance the affinity between the substrate and the coating solution during interfacial polymerization and increase the selectivity of CO2, a mixture of polyethylene glycol (PEG) and dopamine (DOPA) was subjected to a spinning process. Then, the surface of the substrate was subjected to interfacial polymerization using polyethyleneimine (PEI), trimesoyl chloride (TMC), and sodium dodecyl sulfate (SDS). The effect of adding SDS as a surfactant on the structure and gas permeation properties of the fabricated membranes was examined. Thin-film composite hollow fiber membranes containing modified graphene oxide (mGO) were fabricated, and their characteristics were analyzed. The membranes exhibited very promising separation performance, with CO2 permeance of 73 GPU and CO2/N2 selectivity of 60. From the design of a membrane substrate for separating CO2, the CMMMs hollow fiber membrane was optimized using the active layer and mGO nanoparticles through interfacial polymerization

Graphene quantum dots-decorated ZnS nanobelts with highly efficient photocatalytic performances

Hybrid nanostructures combining inorganic materials and graphene have shown great potential for the environmentally friendly treatment of effluents. Herein, graphene quantum dots (GQDs)-decorated ZnS nanobelts have been synthesized via a facile hydrothermal method. The electrostatic attraction of two materials and the thermal reduction of graphene are the main driving forces to fabricate well-defined composite nanostructures. GQDs in GQD/ZnS nanocomposites have been found to exist discretely and uniformly on the surfaces of ZnS nanobelts. The photocatalytic activity of GQD/ZnS nanocomposites has been found to be highest at a GQD/ZnS mass ratio of 8 x 10(-4). The photocatalytic rate constant (0.0046 min(-1)) of GQD/ZnS nanocomposites having the optimized GQD content in the photodegradation reaction of rhodamine B has been found to be 14 times higher than that of commercially available ZnS powder. Decorated GQDs introduce an additional visible-light response and serve as electron collectors and transporters to block electron-hole recombination efficiently, enhancing the photocatalytic performances of ZnS nanobelts immensely

Computed Tomography Angiography of Situs Inversus, Portosystemic Shunt and Multiple Vena Cava Anomalies in a Dog

ABSTRACT. A 5-year-old Shih Tzu was presented with intermittent vomiting and anorexia. Microhepatica and reversed position of the ab-dominal organs were observed on radiography. Ultrasonographically, portosystemic shunt (PSS) was tentatively diagnosed. Computed tomography (CT) revealed that the distended portal vein drained into the left hepatic vein. The caudal vena cava (CdVC) split postrenally and converged at the renal level. Cranial to this, the azygos continuation of the CdVC was confirmed. In the thorax, a persistent left cranial vena cava (CrVC) was found along with right CrVC. This is the first report of a dog with persistent left CrVC and multiple abdominal malformations. CT angiography was useful in evaluating the characteristics of each vascular anomaly and determining the required surgical correction in this complex case. KEY WORDS: azygos continuation of the caudal vena cava, CT, persistent left cranial vena cava, portosystemic shunt, situs inversus. doi: 10.1292/jvms.13-0212; J. Vet. Med. Sci. 75(11): 1525–1528, 2013 Situs inversus is a congenital condition in which the vis-ceral position is reversed as a mirror image. This condition is the main characteristic of Kartagener’s syndrome with rhinosinusitis and bronchiectasis [7]. Situs inversus without dextrocardia has been reported with congenital vascular anomalies including portosystemic shunts (PSS) and azygo