Firewalls fend off invasions from the Net

Whether a computer is in a corporation, government agency, university, small business, or at home, if it is linked to a network, hackers are a risk. The first line of defense against them is a firewall, provided it is set up correctly. Firewall technology is a set of mechanisms that collectively enforce a security policy on communication traffic entering or leaving a guarded network domain. The security policy is the overall plan for protecting the domain. Embodied in hardware, software, or both, a firewall guards and isolates the domain. Broadly, firewalls attempt to maintain privacy and ensure the authenticity of data communications that pass through their domain's boundaries. Whether data is entering or leaving a domain, it is protected from eavesdropping (passive wiretapping) and change (active wiretapping). But only communication traffic entering or leaving a domain comes under the influence of firewall technology     

丹麦钢铁公司板坯连铸机自动化改造

１９９９年９月,奥钢联工程技术公司（ＶＡＩ）自动化部成功完成丹麦钢铁公司板坯连铸机自动化系统改造工程,目标是以更先进的喷淋冷却模型取代老式的喷水控制系统,同时提高板坯质量和铸机产量以及实行更为合理的生产和质量管理。整个改造工程历时仅６个月,其中包括制定技术规范、项目实施、系统调试和试运行改造后,板坯质量、特别是内部裂纹和宏观偏析方面有极大改善。