CIMS企业中应用Push/Pull生产方式的研究

文章首先对MRP＿II和JIT生产方式进行了对比,分析各自的优缺点,并针对性地提出一种适合于CIMS类企业Push／Pull生产方式.然后,作者详细研究了Push／Pull生产方式下原材料投入的Push控制方法和后续加工的Pull控制方法.最后,作者研究了Push／Pull生产方式下生产计划和调度策略的基本框架、系统的总体结构和JIT的主生产计划方法等.     

一种新的RFID传感网络中多阅读器防碰撞协议

阅读器碰撞问题(RCP)是影响射频识别(RFID)系统读取效率的关键问题。提出了一种新的解决阅读器碰撞问题的协议——DREAM协议。新协议根据阅读器间的信号干扰情况在多个阅读器中动态产生若干个临时的控制中心作为簇首,合理安排各个阅读器的读取顺序,完全避免了阅读器间的信息碰撞。理论和仿真结果表明DREAM协议相对于现有性能较优的PULSE协议,在极大地提高系统读取效率的同时,大大地节省了阅读器的功率消耗。     

BIOGENIC AMINES IN FINNISH DRY SAUSAGES

A study was conducted to determine the biogenic amine levels of Finnish dry sausages and to compare the results with those of other surveys of different types of fermented sausages. Sausages with high amine concentration were analyzed microbiologically in order to identify amine-producing microorganisms. Tyramine was the most common amine: the mean of 68 samples was 82 mg/kg and the mode 110 mg/kg. Other vasoactive amines found were histamine (<1–200 mg/kg), phenylethylamine (<1–48 mg/kg) and tryptamine (<10–91 mg/kg). Increased amounts of the spoilage indicator amines putrescine and cadaverine were found from most of the samples containing vasoactive amines. The formation of amines can be linked with problem(s) in hygienic conditions of raw materials and manufacturing practices and it is thus proposed that the sum of tyramine, histamine, putrescine and cadaverine could serve as an indicator of quality in fermented meat products.     

Formation of Biogenic Amines during Ripening of Dry Sausages as Affected by Starter Culture and Thawing Time of Raw Materials

Raw materials affect formation of biogenic amines in dry sausages. Effects of thawing time of raw materials and amine-negative starter culture on amine formation were studied on a pilot scale. The levels of biogenic amines, precursor amino acids, pH, water activity, and microbial counts were measured. Use of starter culture significantly decreased levels of histamine, tyramine and cadaverine formed. The effect of thawing time on formation of biogenic amines was dependent on the use of starter culture.     

Biogenic Amines in Dry Sausages as Affected by Starter Culture and Contaminant Amine-Positive Lactobacillus

The effect of an amine-negative starter culture, containing Pediococcus pentosaceus and Staphylococcus carnosus, on the growth and amine formation of an amine-positive contaminant lactic acid bacterium (G 106) was studied in dry sausages. Levels of biogenic amines, precursor amino acids, pH, water activity and microbial counts were measured. Levels of phenylethylamine and tyramine increased in the sausages inoculated with the amine-positive strain. The starter culture did not prevent growth of G 106 or its amine formation capability. However, levels of histamine remained low although G 106 could produce histamine in vitro.