The decline in water quality is a serious environmental issue, particularly in urban areas. This research aims to develop an Internet of Things (IoT)-based water quality monitoring system using ESP32, pH, TDS, and turbidity sensors. The system is designed to monitor water quality parameters in real-time and transmit data to a cloud platform for further analysis. The system prototype was tested with water samples from various sources, and the results demonstrated high accuracy, with a maximum deviation of ±0.5% compared to laboratory results. Thus, this system offers an efficient and easy-to-implement solution for continuous water quality monitoring, which can aid in water resource management in urban environments.

Police Sector (Polsek) is one of the agencies that provide protection, order and ensure public safety in the sunggal area. The number of cases of criminal acts that occur makes residents feel unsafe and always feel threatened in certain areas in the Sunggal sub-district, the pattern of criminal acts that often occur due to several factors, one of which is due to the lack of security in the area so that many criminal acts occur as well as behaviour that has been planned by the perpetrator to achieve their goals by planning, preparing, implementing, disposing of evidence, even hiding or escaping depending on the type of crime committed based on the characteristics of the perpetrator, and the situation or context in which the crime occurred. Therefore, it is necessary to analyse techniques from existing criminal data using the a priori algorithm method to find patterns of relationships between variables that can assist agencies in taking action for public safety. Based on the research conducted, the above case is tested with a minimum support = 10%, confidence = 100% so that the results of the rule that meets the support and confidence values are obtained: ‘If the criminal act is theft then the job is self-employed’, then giving value is successful with 15% support, 100% confidence. And ‘If the age of 17-25 years, the criminal act is Theft then the job is unemployed’, then giving value is successful with 10% support, 100% confidence.

Cats are one of the beloved animals that require care and development. As beloved animals, cats have their own charm thanks to their different body shapes, eyes and fur colors. Cats whose pedigrees are officially registered as purebred cats. Cats, in Latin Felis silvestris catus, are a type of carnivore. The word cat usually means a domesticated cat but can also refer to large cats such as lions, tigers and leopards. Cats have been mixed with human life for at least 6000 years BC, since cat skeletons were discovered on the island of Cyprus (Arquitectura et al., 2015).  One of the diseases that often appears in cats is feline lower urinary tract disease (FLUTD), also known as feline urological syndrome (FUS), which is a health problem that often occurs in cats, especially male cats. This health problem attacks the cat's bladder and urethra. Urethral disorders are caused by the structure of the male cat's urethra, which is tube-shaped and has a narrow section, which often causes obstruction of urine from the bladder (VU) to the outside of the body. FLUTD includes several diseases that occur in the cat's urinary tract (Indonesia, 2022).  Knowledge about diseases in cats is one of the problems. Many owners do not realize that their cats are suffering from diseases that can cause death. The cause of the cat's death occurred due to the keeper's lack of knowledge regarding the disease and symptoms the cat was experiencing. Apart from that, the problem is that there are so few doctors available that they are difficult to find, and the information obtained is only in accordance with the condition of the cat when it goes to the vet. If you see other symptoms, like it or not, you have to consult the veterinarian again and it will take additional time and money. This problem can be solved with an expert system that can diagnose the disease suffered by the cat based on the selected symptoms.