Update building.rb

  def exp_tech(user, ceho)
    technology = user.technologies.where('bonus_type' => ceho).first!
    research = user.researches.where('technology_id' => technology.id).first!
    lvl = research.lvl
    if lvl =! 0
      if ceho == "L" || ceho == "E"
        1 - lvl * 0.02
      else
        lvl * 0.02 + 1
      end
    else
      lvl = 1
    end
  end