Kode blok adalah skema penyandian yang menggunakan sistem kode-kode pada suatu lapangan hingga dengan panjang yang sama dan tetap. Kode blok linear atau lebih sering disebut kode linear atas suatu lapangan hingga merupakan himpunan kode-kode blok dengan panjang  yang membentuk suatu subruang bagian atas lapangan hingga  dengan  adalah bilangan prima dan  bilangan bulat positif. Sedangkan kode linear  dikatakan kode siklik jika setiap elemennya diputar masih terdapat di himpunan kode linear . Setiap kode blok di kode siklik mempunyai korespondensi dengan semua faktorisasi polinomial tak tereduksi dari polinmial . Umumnya, pembahasan mengenai kode siklik pada lapangan hingga hanya dibatasi oleh Hal ini menyebabkan setiap faktor dari polinomial  adalah tunggal. Untuk , memunculkan suatu pendefinisian baru dari konsep kode siklik. Kode siklik ini disebut disebut kode siklik berulang (repeated cyclic code). Penelitian ini mencakup sifat dan struktur ring  dari kode linear atas ring rangkaian komutatif hingga, kontruksi kode siklik berulang, algoritma dari kontruksi kode siklik atas lapangan hingga  dengan  bilangan prima tertentu.

The archiving process uses a certain system in the preparation, maintenance of records so that they can be recovered quickly and precisely and easily for destruction of archives based on certain criteria. The archive itself has enormous benefits for educational organizations, because the archive is information on activities carried out by schools. Archives in schools need to be well managed, so that archives can be used effectively and efficiently and have good accessibility. The arrangement of archives usually has several problems including, documents cannot be recovered because they are lost, the number of documents is always increasing every day, the storage area for documents is too small compared to the number of documents, so the space is insufficient, not to mention the lack of staff capacity, and the system. The storage is not in accordance with the principles of archiving. For this reason, this service is aimed at providing knowledge and skills in arranging archives in accordance with RI archiving principles, namely using an alphanumeric archive storage system, through training followed by practice and evaluation. Adequate archive facilities and infrastructure are needed in schools for this training. After the dedication was carried out, teachers and administrative staff experienced an increase in knowledge and skills in compiling personal archives and schools got the facilities and infrastructure that supported archiving. Furthermore, an evaluation of the application of archiving in schools is carried out in order to determine its effectiveness in school management.

Ecoenzyme is a solution of complex organic substances produced by the fermentation process of organic waste, water, and molasses. So that organic waste that has been disposed of and is no longer used can be utilized as an environmentally friendly product. This eco-enzyme solution is dark brown in color and has a strong sour aroma. This socialization and demonstration focuses on making Ecoenzyme solutions from organic waste grapefruit, pumpkin, kale, chicory and papaya from household waste which aims to educate the public, especially housewives in Tanjung Kasau Plantation Village to know the procedure for making Ecoenzyme and using waste organic. Using an experimental method, an Ecoenzyme solution was made with 1 part molasses, 3 parts fruits and vegetables, and 10 parts clean water and then fermented for 3 months to make an Ecoenzyme solution. For the first 1 month the test was carried out Periodically, samples are taken every 2 days and evaluated for find out the evaluation parameters including organoleptic, pH and appropriate viscosity established test procedures. The results of this study showed that a good Ecoenzyme had a dark brown color, a fresh sour aroma typical of spicy and get a stable pH with a pH of 4.0 showing a high eco-enzyme produced is acidic which has benefits such as radiation protection, clearing drains, floor cleaners, organic disinfectants etc.

Education is an attempt by the Government to increase the country's potential to be able to compete with other countries that are experiencing very rapid development. The development of education will have an influence on the life of the local community, that is, it can affect various aspects of life, be it social, economic, cultural, religious, language and also the environment. The extent of the influence of educational development on aspects of life can be studied independently. Besides that, education also plays a major role in expanding employment opportunities, encouraging activities of supporting industries, introducing natural and cultural beauty that is inseparable from a sense of increasing brotherhood in the national and international environment. This is because education itself creates multiple economic impacts, namely direct, indirect, and secondary impacts, which provide opportunities for the growth of businesses and the role of local communities in the education sector. This research will discuss about Active Learning Training with Mathematics Tools at SDS HKBP Pembangunan 3 Medan. The result achieved is that schools are able to provide effective services online in the face of changing times caused by Covid-19 and can provide more information regarding the location of tourist objects that will be traversed by local and foreign tourists.