22 research outputs found
Prediction of tool wear using machine vision approach
Tool wear prediction plays a crucial role in the machining industry for proper
planning and optimization of cutting conditions. Nevertheless, tool wear assessment method
using sensor signals has its drawbacks in the industry application. The objective of this study is
to apply Artificial Neural Network (ANN) prediction model and machine vision system to
predict flank wear in turning operation based on the texture images of machined surface
captured by complementary metal oxide semiconductor (CMOS) camera in-cycle. The image
pre-processing technique was utilized to enhance the quality of surface texture images acquired
from the experiment and the texture descriptors were extracted from the processed images using
gray-level co-occurrence matrix (GLCM). Three ANN prediction models with different input
variables were developed using MATLAB software. The findings showed that the ANN
prediction model with input variables of contrast, entropy, cutting speed, and feed rate
outperformed the other ANN prediction model. The prediction accuracy of this model in
estimating flank wear reached up to 93.18%. A very good fit and the relationship could be
found in this model with R2
of 0.9863 for flank wear
Kajian persepsi arkitek terhadap pelaksanaan bumbung hijau di Malaysia: faedah, halangan dan cadangan
Pelaksanaan bumbung hijau sebagai kaedah mampan untuk menangani kesan pulau haba bandar masih baru di Malaysia. Walaupun bumbung hijau belum diuji pada skala bandar, beberapa kajian telah menunjukkan bahawa bumbung hijau dapat mengurangkan impak perbandaran dan meningkatkan kualiti alam sekitar. Pelaksanaannya yang rendah di Malaysia adalah disebabkan oleh pelbagai faktor seperti faktor kos dan kekurangan kesedaran di kalangan penggiat industri pembinaan. Kajian ini bertujuan untuk mengenal pasti persepsi arkitek tempatan terhadap pelaksanaan bumbung hijau dan mengenal pasti faedah, halangan dan cadangan untuk menangani halangan pelaksanaan bumbung hijau. Kaedah soal selidik telah digunakan untuk menilai pandangan arkitek tempatan terhadap sepuluh faedah, sembilan halangan pelaksanaan bumbung hijau dan lapan cadangan untuk menangani halangan bumbung hijau. Keputusan yang didapati menunjukkan bahawa faedah bumbung hijau yang paling penting adalah untuk mengurangkan kesan pulau haba bandar (N = 8.14), manakala faedah bumbung hijau yang paling lemah adalah untuk meningkatkan penebat haba bumbung (N = 3.73). Halangan untuk melaksanakan bumbung hijau yang paling penting adalah kekangan pelaksanaan daripada pelanggan (N = 4.22), manakala halangan untuk melaksanakan bumbung hijau yang paling lemah adalah kerana arkitek kurang yakin dengan faedah bumbung hijau (N = 2.62). Cadangan untuk menangani halangan pelaksanaannya yang paling penting adalah melalui memperbanyakan insentif kepada penggiat bumbung hijau (N = 4.37), manakala cadangan yang paling lemah merupakan membawa masuk kepakaran luar dan pertukaran teknologi (N = 3.65). Hasil kajian ini dapat membantu mempromosikan pelaksanaan bumbung hijau di Malaysia dan meningkatkan penyumbangan bumbung hijau kepada persekitaran dalaman dan luaran bangunan
Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.
BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700
Early-Age Cracking in Concrete: Causes, Consequences, Remedial Measures, and Recommendations
Cracking is a common problem in concrete structures in real-life service conditions. In fact, crack-free concrete structures are very rare to find in real world. Concrete can undergo early-age cracking depending on the mix composition, exposure environment, hydration rate, and curing conditions. Understanding the causes and consequences of cracking thoroughly is essential for selecting proper measures to resolve the early-age cracking problem in concrete. This paper will help to identify the major causes and consequences of the early-age cracking in concrete. Also, this paper will be useful to adopt effective remedial measures for reducing or eliminating the early-age cracking problem in concrete. Different types of early-age crack, the factors affecting the initiation and growth of early-age cracks, the causes of early-age cracking, and the modeling of early-age cracking are discussed in this paper. A number of examples for various early-age cracking problems of concrete found in different structural elements are also shown. Above all, some recommendations are given for minimizing the early-age cracking in concrete. It is hoped that the information conveyed in this paper will be beneficial to improve the service life of concrete structures. Concrete researchers and practitioners may benefit from the contents of this paper
Development of an Assessment Method to Evaluate the Quality of Remedial Treatments on Concrete Flat Roofs of Multiple Buildings
Existing assessment tools have not been successfully used to evaluate the performance of the remedial treatment of concrete flat roofs by building users or building management personnel because they are complicated and difficult to be applied by non-experts. In this study, a semi-quantitative method has been developed to assess the quality of remedial treatment on concrete flat roofs of multiple buildings. A 10-point scale weighting was calculated based on the results of ranking, and then the score assessment scheme was developed. Results revealed that the repairing principles included protection against ingress (W = 7.25), physical resistance against ingress (W = 5.23), concrete restoration (W = 8.22), structural strengthening (W = 8.22), moisture control (W = 6.59), and chemical resistance (W = 4.57). The grouped principles included physical resistance (W = 6.24), structural stability (W = 8.22), and chemical resistance (W = 5.58). The scoring assessment scheme was applied to a remedial treatment on multilayer concrete flat roof which was treated with bituminous membrane. The assessment scheme was revised based on the surveyors’ comments and then verified by the experts. This assessment method secured and improved the quality of the remedial treatment, since the building management staff/owner successfully evaluated, controlled, and monitored the quality of remedial treatments
E2F and STAT3 provide transcriptional synergy for histone variant H2AZ activation to sustain glioblastoma chromatin accessibility and tumorigenicity
10.1038/s41418-021-00926-5CELL DEATH AND DIFFERENTIATION2971379-139