Viec xay buc tuong la phi pham va khong huu hieu? Lam on chung minh la tai sao nhu vay, xin dung noi chung chung. Gia su nha minh co san rong, neu khong co buc tuong chan khong cho ke la xam nhap thi chung ta dung cai gi de ngan can ho? Dung he thong dien tu nhu dang DC de nghi? Cai nao re hon hay mac hon? cai nao huu hieu hon cai nao? (chu y den ca van de xay dung (build) va duy tri (maintenance)). Neu la cho hang rao quanh nha cua minh thi ban nghi se xay tuong hay dung thiet bi dien tu?