PC computer is a flexible electronic device and can receive and process data quickly and accurately, and can also store data for a long time. There is a time when the PC hardware is damaged. So that it annoys the user. In connection with the problems that occur, the researchers aim to build an Expert System application to diagnose damage to PC computers using the Certainty Factor method by using Visual Studio 2010 applications and using Microsoft Access 2013 as a database. Applications that are built can be an alternative in knowing the type of damage and provide alternative solutions in handling damage to PC computer hardware.

Chicken disease is a condition in which the body organs of chickens cannot function normally. Diagnosing a disease requires symptoms that appear on the chicken’s body. To conduct a disease diagnosis, further examination is needed by specialists (experts). An expert system is a system that uses human knowledge that is entered into a computer to solve problems that are usually resolved by experts. The system created in solving problems uses the Bayes Theorem method in which the inference process uses Forward Chaining. The application was developed using the visual basic 2010 programming language and MySQL database.

In rural areas there are still many residents 'houses that are unfit for habitation and this is due to the factor of the standard of living of people who are still living simply and have below average income, these conditions make many residents' houses unfit for habitation that need to be repaired through assistance Home renovation. The Weighted Product method can help in making decisions, but the calculation using the Weighted Product method only produces the largest value which will be selected as the best alternative. The design of decision-making for housing renovation assistance recipients at the Housing and Settlement Areas is based on criteria, namely Indonesian citizens, below average income, belonging to a family, owning or controlling land, not having a house or owning and living in an uninhabitable house using the Weighted Product method. Application design using the programming language PHP and MySQL

Salah satu pesta demorasi masyarakat adalah pemilihan kepala Desa, pemilihan kepala desa dilakukan di tingkat desa secara langsug untuk  menentukan  pemimpin  Desa  atau  kepala  Desa.  Sistem pendukung keputusan   merupakan   suatu   alternatife   sistem   yang   interaktif   yang dapat  membantu   dalam pengambilan keputusan  melalui  penggunaan  data  dan  model-model  keputusan  untuk  memecahkan  masalah yang  bersifat  semi  terstruktur  maupun  yang  tidak  terstruktur. Sistem ini dibangun dengan menerapkan  metode SAW (Simple  Additive   Weighting)  dimana Konsep  dasar metode  SAW  yaitu  mencari  penjumlahan terbobot  dari  rating  kinerja  pada  setiap  alternatif  pada  semua  atribut.  Pada perhitungan   metode SAW ini hanya yang menghasilkan nilai terbesar yang akan terpilih sebagai alternatif  yang  terbaik.  Perhitunganakan  sesuai  dengan  metode  ini  apabila  alternatif  yang terpilih  memenuhi  kriteria  yang  telah  ditentukan.  Dengan  Menggunakan  sistem  pendukung keputusan pemilihan calon kepala Desa yang memakai metode Simple Additive Weigtihng (SAW) ini  membantu  warga  masyarakat  untuk  mengetahui  perangkingan  calon kepala  Desa dari  hasil  bobot  kriteria  yang  telah  di  tentukan, sehingga  memberi  informasi tambahan saat akan menetukan pilihan dalam pesta demokrasi warga masyarakat di desa situnggaling.

Eye disease due to frequent use of computers is one of the dangerous diseases in health because if not treated quickly it will result in blindness. These eye diseases can be diagnosed through the symptoms that arise in humans or through their clinical picture, through these symptoms an expert system can be made to make a diagnosis. An expert system is a system that seeks to adopt human knowledge to a computer that is built to solve problems like an expert. The expert system made in carrying out the diagnosis uses the Bayes theorem method to calculate the probability of an event occurring based on the influence obtained from the results of observations and experts. The system was built using PHP and MySQL programming as a database. The method used for tracing is Bayes' theorem. While the results of the diagnosis will inform about the results of the diagnosis containing a list of symptoms entered, information on the results of the rules regarding the eye disease suffered and information about possible treatments that can be carried out as well as treatment solutions.