The capture of a target spacecraft by a chaser is an on-orbit docking operation that requires an accurate, reliable, and robust object recognition algorithm. Vision-based guided spacecraft relative motion during close-proximity maneuvers has been consecutively applied using dynamic modeling as a spacecraft on-orbit service system. This research constructs a vision-based pose estimation model that performs image processing via a deep convolutional neural network. The pose estimation model was constructed by repurposing a modified pretrained GoogLeNet model with the available Unreal Engine 4 rendered dataset of the Soyuz spacecraft. In the implementation, the convolutional neural network learns from the data samples to create correlations between the images and the spacecraft’s six degrees-of-freedom parameters. The experiment has compared an exponential-based loss function and a weighted Euclidean-based loss function. Using the weighted Euclidean-based loss function, the implemented pose estimation model achieved moderately high performance with a position accuracy of 92.53 percent and an error of 1.2 m. The in-attitude prediction accuracy can reach 87.93 percent, and the errors in the three Euler angles do not exceed 7.6 degrees. This research can contribute to spacecraft detection and tracking problems. Although the finished vision-based model is specific to the environment of synthetic dataset, the model could be trained further to address actual docking operations in the future.
In one, docking is defined as “when one incoming spacecraft rendezvous with another spacecraft and flies a controlled collision trajectory in such a manner to align and mesh the interface mechanisms”, and defined docking as an on-orbital service to connect two free-flying man-made space objects. The service should be supported by an accurate, reliable, and robust positioning and orientation (pose) estimation system. Therefore, pose estimation is an essential process in an on-orbit spacecraft docking operation. The position estimation can be obtained by the most well-known cooperative measurement, a Global Positioning System (GPS), while the spacecraft attitude can be measured by an installed Inertial Measurement Unit (IMU). However, these methods are not applicable to non-cooperative targets. Many studies and missions have been performed by focusing on mutually cooperative satellites. However, the demand for non-cooperative satellites may increase in the future. Therefore, determining the attitude of non-cooperative spacecrafts is a challenging technological research problem that can improve spacecraft docking operations. One traditional method, which is based on spacecraft control principles, is to estimate the position and attitude of a spacecraft using the equations of motion, which are a function of time. However, the prediction using a spacecraft equation of motion needs support from the sensor fusion to achieve the highest accuracy of the state estimation algorithm. For non-cooperative spacecraft, a vision-based pose estimator is currently developing for space application with a faster and more powerful computational resource.
คณะแพทยศาสตร์
Migraine, a prevalent neurological disorder, is the third most common disease globally, causing significant health and financial burdens. It has four stages: prodrome, aura, headache, and postdrome. The prodrome (also known as premonitory) stage is crucial as it precedes the headache by up to 72 hours. Taking medication during the premonitory peroid has shown to prevent the headache phase . However, the symptoms of premonitory period lack specificity, making it difficult for patients to know if they’re experiencing premonitory symptoms. Calcitonin-gene related peptide (cGRP),is a protein that plays a key role in migraine pathogenesis and studies found that salivary cGRP levels increase during the premonitory stage. This study aims to develop and evaluate a lateral flow immunoassay kit for detecting salivary cGRP levels in migraine patients during the prodrome stage. It can serve as a confirmation tool for premonitory symptoms.
คณะสถาปัตยกรรม ศิลปะและการออกแบบ
The thesis artwork titled “The Red Mist” presents a narrative adapted from a short story of the same name by Assistant Professor Chatnarong Wisutkul in 2003. The story is set in a future world where people's greed and selfishness have led to a war, forcing them to rely on "breathing machines" to survive in the "red toxic mist." Phakin, a 15-year-old boy, embarks on a journey with a group of refugees. As they pass through abandoned cities, they encounter a boy without a breathing machine who has recently lost his father. Phakin decides to help him, despite objections from others. The boy tries to end his life by shutting off his breathing machine, and when Phakin intervenes to save him, he collapses from inhaling the toxic air. Witnessing Phakin's selfless act, the others are moved and join forces to save both of them. Phakin demonstrates that in difficult times, humans must cooperate and help each other rather than being divided and selfish.
คณะอุตสาหกรรมอาหาร
Most rice is consumed as cooked, milled rice, but a small portion is also ground into flour or separated into a starch fraction and used by the food industry as a gluten-free ingredient. This study aims to find out if different types of rice flour and starch, such as white and colored rice, could be used in industry. This study employs green modification techniques to slow down the digestion process by combining polyphenols with starch. Our initial study found that the raw colored rice has a lower glycemic index than other types of rice, such as brown or white rice. Another study that looked at how the quality of colored rice flour was changed by different methods also discovered that out of the six green methods (annealing, heat moisture treatment, ultrasound, pregelatinization, wet-microwave, and dry-microwave). It found that ultrasound improved the polyphenol bioaccessibility in the rice flour and reduced the digestion rate. The pregelatinization process led to the flour having high solubility and an estimated glycemic index. Different techniques affected the flour/starch quality in different ways. Therefore, for further industrial application, it could also be easier to select the method for food product based on their required techno-functional quality of flour/starch. In addition to the modification techniques, this study showed that the high bioaccessible polyphenol content and high polyphenol content in rice greatly slowed down the rate of digestion. This study also open for further exploring the possibility of using high polyphenol agricultural waste to modify starch and flour in a sustainable manner.