Satellite reliability is critical to ensuring uninterrupted operations in aerospace systems, where anomalies can lead to mission failures and significant economic losses. Existing anomaly classification methods often lack scalability, interpretability, and adaptability to diverse datasets. This study introduces the Trade-Space Exploration Machine Learning (TSE-ML) framework, a comprehensive pipeline for satellite anomaly classification that optimizes preprocessing, transformation, normalization, and machine learning stages. Leveraging a Seradata dataset spanning 66 years and 4,455 satellite records, the framework systematically evaluates four data cleaning methods, four data transformation techniques, five normalization strategies, and seven machine learning algorithms across 480 configurations. The optimal configuration, comprising Iterative Imputation, FastText, Robust Scaling, and Decision Tree, achieved the highest testing accuracy of 95.74% with competitive computational efficiency. The Decision Tree model delivered superior accuracy and provided interpretability, revealing critical factors influencing satellite anomalies, such as Age Since Launch, Design Life, and Orbit Category. Stratified 5-fold cross-validation ensured robustness and generalizability of the results. The TSE-ML framework’s transparency and high performance enable actionable insights for improving satellite design, operational planning, and anomaly mitigation. Future research will focus on real-time anomaly detection, integrating satellite telemetry data, and extending the framework to other space applications. This study establishes a robust, interpretable foundation for advancing anomaly classification in aerospace engineering, addressing the dual challenges of reliability and operational efficiency.

Earth station system plays an important role to ensure that a satellite communication system runs efficiently. Redundancies of the subsystems and regular maintenance planning can improve the earth station system. Organising system affordability can be challenging as more redundancies would acquire more maintenance. Thus, a sustainable framework that considers an earth station system's reliability, cost, and maintainability was modelled. 2-parallel, 3-parallel, and 4-parallel earth station system configurations were studied with five mean time between failures (MTBF). The results showed that an earth station that was configured with 2-parallel configuration provided an optimum reliability system performance though both 3-parallel and 4-parallel configuration provided higher reliability. Moreover, the 2-parallel configuration was also cheaper in terms of operational cost if compared to the 3-parallel and the 4-parallel configurations. Hence, this sustainable framework comprising the reliability and operational cost elements were modelled based on the 2-parallel configuration with the proposed maintenance activities. Moreover, the computed root mean square (RMS) values for both new reliability and new operational cost models yielded smallest values of 20.84% and 22.82% respectively. Thus, these RMS values for both reliability and operational cost models based on 2-parallel configuration are suitable to be applied in the earth station system design.

Systems engineering traditionally approaches the design of systems through determination of requirements for and implementation of a system. The system is conceived as something to enable achievement of an effect with the tacit assumption that the system to be designed must achieve technical performance, including availability characteristics, which enable delivery of the whole of the intended effect. This approach determines the technical requirements of the system to ensure achievement of the system purpose under assumptions about how the system, or fleet, would be deployed to provide the intended service. Usually, cost is addressed after requirements, either to find the cheapest method to achieve the requirements or as one dimension of a trade-space analysis. In this paper, we explore a different philosophy for finding the system requirements; starting with the required system level service provision, but agnostic about the technical quality needed. We investigate a trade-space including the life cycle cost (LCC) of service provision as a contribution to determining subsystem requirements. We model the life cycle, for many variations of technical composition, using a Monte Carlo method, and show that a trade-space of LCC and requirements is likely to produce a cheaper solution than starting with sub-system requirements.

Operational cost is important in any system. In the case of the earth station system, operational cost is very crucial. The operational cost can be divided into three costs: maintenance, failure, and replacement costs. There are many complex subsystems incorporated in the earth station system, for instance a high-power amplifier, modulators, and antennas, to name a few. In this research, only the replacement cost was considered. Moreover, there are many replacement methods that are available. These replacement methods implicitly influence both the replacement and the replacement costs. The aim of this research is to provide a new cost model based on which replacement method yields the lowest cost. Two replacement methods are involved in this research: failure-triggered and age-based. The failure-triggered and the age-based replacement methods were considered because these methods are the most used in previous research work. Furthermore, three types of cost models were also considered, and they were linear, polynomial, and exponential operational cost models. The outcomes show that the failure-triggered and age-based replacement methods of 2-parallel configuration of polynomial and linear operational cost models yielded the lowest RMSE value of 2.5. Therefore, both polynomial and linear operational cost models of the 2-parallel configuration were the most optimal operational cost models. ABSTRAK: Kos operasi adalah penting dalam mana-mana sistem. Dalam kes sistem stesen bumi, kos operasi adalah sangat penting. Kos operasi boleh dibahagikan kepada tiga kos: kos penyelenggaraan, kegagalan dan penggantian. Terdapat banyak subsistem kompleks yang digabungkan dalam sistem stesen bumi, contohnya penguat kuasa tinggi, modulator, dan antena. Penyelidikan ini hanya membincangkan tentang kos penggantian. Selain itu, terdapat banyak kaedah penggantian sedia ada. Kaedah penggantian ini secara tersirat mempengaruhi kedua-dua kos penggantian dan penggantian. Matlamat penyelidikan ini adalah bagi menyediakan model kos baharu berdasarkan kaedah penggantian yang menghasilkan kos terendah. Dua kaedah penggantian yang terlibat dalam kajian ini: penggantian yang dicetuskan oleh kegagalan dan berdasarkan umur. Kaedah cetusan kegagalan dan penggantian berasaskan umur telah dipertimbangkan kerana kaedah ini paling banyak digunakan dalam penyelidikan terdahulu. Tambahan, tiga jenis model kos turut dipertimbangkan, iaitu model kos operasi linear, polinomial dan eksponen. Dapatan menunjukkan kaedah penggantian cetusan kegagalan dan berdasarkan umur melalui konfigurasi model 2 selari bagi kos operasi polinomial dan linear menghasilkan nilai RMSE terendah iaitu 2.5. Oleh itu, kedua-dua model kos operasi polinomial dan linear bagi konfigurasi model 2 selari adalah kos operasi paling optimum.

The emerging of inductive wireless power transfer (IWPT) technology provides more opportunities for the electric vehicle (EV) battery to have a better recharging process. With the development of IWPT technology, various way of wireless charging of the EV battery is proposed in order to find the best solution. To further understand the fundamentals of the IWPT system itself, an ample review is done. There are different ways of EV charging which are static charging (wired), static wireless charging (SWC) and dynamic wireless charging (DWC). The review starts with a brief comparison of static charging, SWC and DWC. Then, in detailed discussion on the fundamental concepts, related laws and equations that govern the IWPT principle are also included. In this review, the focus is more on the DWC with a little discussion on static charging and SWC to ensure in-depth understanding before one can do further research about the EV charging process. The in-depth perception regarding the development of DWC is elaborated together with the system architecture of the IWPT and DWC system and the different track versions of DWC, which is installable to the road lane.

Satellites are essential for modern communication, navigation, and Earth observation, but their operation in the harsh space environment makes them vulnerable to anomalies and failures, resulting in significant financial losses. This research investigates the relationship between the design life of satellite subsystems and the cost of anomalies, using data from the Seradata database. Three statistical models, Exponential, Weibull, and Poisson distributions, were applied to cost data for four critical subsystems: antenna, payload, power system, and attitude control. Each model was fitted using one-variable (cost only) and two-variable approaches (design life and cost) to evaluate subsystems' behaviour independently and in combination. The performance of each model was assessed using the Root Mean Square Error (RMSE) and the Relative RMSE (RRMSE). Among all models, the Exponential distribution consistently produced the best results. For instance, the payload subsystem achieved the lowest RMSE and RRMSE of 115.73 and 41.66% in the two-variable case. Similarly, the attitude control subsystem showed strong performance with an RMSE of 110.57 and RRMSE of 40.59%. In contrast, the Poisson distribution yielded the highest errors across most subsystems, with the antenna subsystem reaching an RMSE of 489.87 and RRMSE of 102.65% in the two-variable fitting. The Weibull model demonstrated mixed performance, performing moderately for the payload subsystem (RMSE 186.21, RRMSE 67.03%), but poorly for the power system and antenna subsystems, particularly when two variables were used. ABSTRAK: Satelit memainkan peranan penting dalam komunikasi moden, navigasi, dan pemerhatian bumi, namun operasinya dalam persekitaran angkasa lepas yang ekstrem menjadikannya terdedah kepada anomali dan kegagalan, sekali gus membawa kepada kerugian kewangan yang besar. Kajian ini mengkaji hubungan antara jangka hayat reka bentuk subsistem satelit dengan kos anomali menggunakan data daripada pangkalan data Seradata. Tiga model statistik iaitu taburan Eksponen, Weibull, dan Poisson telah digunakan pada data kos bagi empat subsistem kritikal: antena, muatan, sistem kuasa, dan kawalan sikap. Setiap model dipadankan menggunakan pendekatan satu pemboleh ubah (kos sahaja) dan dua pemboleh ubah (jangka hayat reka bentuk dan kos) bagi menilai tingkah laku subsistem secara individu dan gabungan. Prestasi setiap model dinilai menggunakan Ralat Punca Min Kuasa Dua (RMSE) dan Relatif RMSE (RRMSE). Antara semua model, taburan Eksponen secara konsisten memberikan dapatan terbaik. Sebagai contoh, dalam subsistem muatan, ia mencapai nilai RMSE dan RRMSE terendah iaitu 115.73 dan 41.66% masing-masing bagi kes dua pemboleh ubah. Begitu juga, subsistem kawalan sikap menunjukkan prestasi kukuh dengan RMSE 110.57 dan RRMSE 40.59%. Sebaliknya, taburan Poisson menghasilkan ralat tertinggi dalam kebanyakan subsistem, dengan subsistem antena mencatatkan RMSE 489.87 dan RRMSE 102.65% dalam padanan dua pemboleh ubah. Model Weibull pula menunjukkan prestasi bercampur, sederhana dalam subsistem muatan (RMSE 186.21, RRMSE 67.03%) tetapi lemah bagi subsistem sistem kuasa dan antena, khususnya apabila dua pemboleh ubah digunakan.