No abstract

Tsunamis are one of the most unforeseen natural disasters, factors or signs of a tsunami occurring among others is the sudden reflux of seawater which is due to the broken plate of the underlying seafloor receding water, the plate fault is caused by seismic ground-based earthquakes, areas ever experienced a previous fault is likely to occur in the same quake place this is because the slabs can not coalesce or return like the original. for it needed a prototype system that can be detected the early detection of a tsunami that could cost many lives, The method used is Continuous Wave Method or Ultrasonic Echo Pulse Method.

No abstract

Kebutuhan antena dalam jaringan nirkabel semakin meningkat. Selain itu, diperlukan sebuah antena yang kecil dan fleksibel mengingat banyak piranti yang bersifat mobile, sehingga antena mikrostrip menjadi pilihan yang terbaik. Salah satu contoh piranti itu, yaitu wireless sensor. Dalam konsepnya sendiri, wireless sensor merupakan jaringan dari beberapa sensor yang terdistribusi dan dikontrol oleh komputer dalam jarak jauh. Setiap sensor memiliki perangkat lunak dan perangkat keras yang kemudian digabung dan dijalankan dalam sebuah sistem sensor tanpa kabel. Frekuensi umum yang digunakan pada piranti ini sama dengan wifi. Oleh karena itu, dalam penelitian ini dibuatlah antena mikrostrp polarisasi circular dengan model patch Yin-Yang pada frekuensi 2.5 GHz untuk wireless sensor. Dari hasil simulasi antena dengan menggunakan software didapatkan return loss sebesar -16.5847 dB dengan lebar pita bandwidth sebesar 292.6 MHz atau 11.85%. Nilai VSWR sesuai dengan yang diharapkan yaitu < 2, dengan nilai 1.3479. nilai axial ratio didapatkan 1.1202 dB, sehingga polarisasi circular. Untuk nilai matching sebesar (1.2433 -0.2290j)Ω.

There is no periodic scheduling of Air Conditioner (AC) maintenance, which stems from the lack of recording on the maintenance card and maintenance book, resulting in a lot of AC damage that propagates from one component to component until finally the AC cannot function completely. A system is needed to provide information that will remind the time of maintenance as the first step in optimizing the life of the air conditioner. The purpose of this study is to build an information system of maintenance-reminder, so that the air conditioner used is maintained according to a predetermined schedule. The method used to build this system is a waterfall with five steps, namely: analysis, design, implementation, and testing. To Test the system that has been made, in this study using black box-testing by checking every part of each system. Our findings are to produce a standardized maintenance reminder system. The test results show that all components in the system are functioning properly, so it is easier for users to know which air conditioners need maintenance. With this system, it can maximize the maintenance function to optimize service life.