The study of a thin-walled column structure has gained much attention due to its potential in many engineering applications, such as the crash box of a car. A thin-walled square column usually exhibits high initial peak force, which may become very dangerous to the driver or passenger. To address this issue, introducing some shape patterns, e.g., origami folding pattern, to the column may become a solution. The present work investigates the compressive properties and behavior of a square box column structure which adopts the Miura origami folding pattern. Several test pieces of single-cell Miura origami column with varying folding angle and layer height are fabricated by a 3D printer. The filament is made of Polylactic Acid (PLA), which is a brittle material. Then, compression tests are carried out to understand its compressive mechanical properties and behavior. The results show that introducing a Miura origami pattern to form a thin-walled square column can dramatically lower down the initial peak stress by 96.82% and, at the same time, increase its ductility, which eventually improves the energy absorption capacity by 61.68% despite the brittle fracture behavior.

Some challenges in the development of autonomous vehicles, such as generating a model representing the dynamics of the speed, designing a longitudinal controller, and the optimization method, are still explored until now. In this paper, a longitudinal controller based on the proportional-integral-derivative controller with an additional feedforward term is proposed, where the Flower Pollination Algorithm is employed for optimizing the controller. The feed-forward term and the model used in the optimization are generated using the data-driven approach. For the optimization, a cost function considering mean absolute error and mean absolute jerk will be minimized. The simulation study was performed using the CARLA simulator, and the results show that the proposed scheme represents the dynamics of the speed very well inside the range of the training data and does not overfit the training data. It is also demonstrated that the proposed longitudinal controller can track the desired speed satisfactorily in a non-straight path.

Li4Ti5O12 (LTO) anode doped with Al ions with varying concentrations (Al = 0; 0.005; 0.015; 0.03; 0.045) was successfully synthesized using the sol-gel method. Al-doped LTO samples were obtained through the sintering of gel at 850oC for 4 hours under a normal atmosphere. Electrochemical performance such as charge-discharge capacity and diffusion coefficient were characterized using an automatic battery cycler. The cells consist of electrode sheets (LTO doping Al) as a working electrode, lithium metal as the counter electrode, Celgard film as the separator, and LiPF6 as an electrolyte. Cyclic voltammetry test results show that a greater scan rate results in decreased capacity and greater polarization voltage. In addition, an increase in concentrations used in Al doping on LTO causes capacity, and the diffusion coefficient tends to decrease.

Total length of paved road in Rajshahi City is about 186.64 km (2011 census). It shows that about 23% of total road lengths are present in failure condition. This study shows an investigation to compute the flexible pavement’s failure types, to define and identify the causes, and select the best maintenance for that failures of flexible pavement within Rajshahi City. There are many types of failures occur on the roads such as different types of cracks, potholes, raveling, water bleeding, corrugation and shoving, depression, and rutting. The possible causes of flexible pavement failures are improper bituminous mixes with poor quality of materials, heavy traffic loads, heavy rainfall, and bad drainage on pavement. The failures are gradually raised due to lack of proper planning, inspection, and treatment. These failures create different types of disadvantages like traffic jam, discomfort to the passengers as well as drivers, increasing vehicle operating, maintenance cost, etc. This study proves that the authorities practice maintenance procedures to repair the failures of pavement which are about 60% similar to the conventional road maintenance procedures. The authorities as Roads and Highway Department and Rajshahi City Corporation are suggested to do maintenance according to the requirements of urgent maintenance and availability of fund which is found in this investigation.

Nowadays, motorcycle is considered as one of the most practical transportation mode in Indonesia. It has become a common practice that a motorcycle rider often brings a small child using a child seat while riding. However, the used child seat is usually not safe and can easily fall off from the motorcycle due to the lack of safety consideration. Moreover, it is very risky to ride a motorcycle with a small child, knowing that motorcycles are the highest contributor to road traffic accidents. For this reason, this paper proposes a primary design idea of a foldable child safety-seat that can be placed on the front part of a scooter motorcycle. This design is also completed with strength analysis to evaluate the components’ safety for children under five years old with a weight of around 50 kg. The strength calculation of the frame is done by a theoretical approach under static and dynamic loading. According to the analysis, the proposed child seat design could provide a factor of safety of more than 3.6 for static loading and 1.6 for dynamic loading. This study is expected to be used as a reference for developing a more reliable child safety- seat for motorcycle rider in Indonesia.