Tensor Product Production System: a Modular Architecture and Representation

Can connectionist networks effectively represent and process structure? A technique called ‘tensor product representations’, which formalizes and generalizes the approaches of several previous connectionist models, was developed by Smolensky and shown to possess a number of desirable general properties. This paper shows how the technique can be effectively used to design a specific symbol-processing task: the serial execution of simple production rules requiring pattern matching, variable binding and structure manipulation. This ‘Tensor Product Production System’ is applied to one of the classes of production rules in Touretzky and Hinton's Distributed Connectionist Production System, and a number of comparisons are made between the two approaches. The mathematical simplicity and analyzability of the tensor product scheme allows the straightforward design of a simpler, more principled, and in some ways more efficient system.     

定向凝固单相Sn-2%Sb合金的胞/枝晶转变、枝晶生长和显微硬度（英文）

采用单相Sn-2%Sb(质量分数)合金进行水平定向凝固实验,分析凝固热参数对显微组织形貌和长度尺度的影响。在凝固过程中,对沿铸坯长度方向的不同部位进行连续温度测量,用这些温度数据来确定凝固热参数,包括生长速率(V_L)和冷却速率(T_R)。高冷却速率的胞晶和枝晶可以表征铸件不同区域的显微组织,当T_R5.0 K/s时发生枝晶向胞晶的可逆转变。沿定向凝固铸造的长度方向确定胞晶尺寸(λ_c)和一次枝晶间距(λ_1),提出关于λ_c和λ_1与V_L和T_R的实验生长规律,并与垂直向上定向凝固实验结果进行对比分析,并分析显微组织形貌和长度尺度对显微硬度的影响。     

Real-Time lethality Evaluation During the Flame Sterilization of Canned Foods

A pilot-scale flame sterilizer was interfaced to a microcomputer for real-time thermal process evaluation of individual cans. The computerized system used a photodetector system to synchronize data acquisition at predetermined monitoring sites. Infrared sensors were used to measure can temperatures. Also, a method to measure can surface temperature was developed for infrared sensor calibrations. Foil thermocouples were found to be the most accurate and reliable for surface temperature measurements. However, a thin gauge wire thermocouple attached to the inside of the can end surface was a more practical and economical method for sensor calibration.     

LINKING MICROBIOLOGICAL CRITERIA FOR FOODS WITH QUANTITATIVE RISK ASSESSMENT

The current annual risk of acquiring a foodborne disease in the United States is estimated at 2.7 × 10^-2. The risk of associated death is estimated at 3.7 × 10^-5. These represent a health care burden >$3 billion. Using a risk assessment model one can identify levels of microbial contamination which may be unacceptable in foods and appropriate controls needed to reduce these levels. Salmonella bacteria continue to represent a large percentage of the identifiable infections. A model developed from human dose-response studies predicts the probability of infection for Salmonella at 7.5 × 10^-3 with exposure to a single CFU of the organism. Risks of severity (hospitalization), mortality, reactive arthritides, and mortality in the elderly are estimated at 3.1 × 10^-6, 7.5 × 10^-6, 1.7 × 10^-5, and 2.8 × 10^-4. Exposure to microbial contaminants needs to be evaluated on a single meal basis. For chicken, exposure may range from a single drum stick (38g) to a half broiler (176g) but averages around 80g. For beef between 51 and 85g may be consumed during a single meal. Therefore, methods for monitoring must be able to detect at least 1 CFU/80g. Risks for some pathogenic E. coli are estimated at 1,000 to 10,000 less than Salmonella. Therefore, use of coliforms as indicators needs to be assessed and related to occurrence and survival and regrowth potential of the enteric bacteria of greater public health concern. Because, 20% of the U.S. population may be considered to be in a special population category and at an increased risk of severe outcomes, no more than 20% failure of a standard should be acceptable .     

RHEOLOGICAL CHARACTERIZATION OF COMMERCIALLY PROCESSED FLUID MILKS

Flow profiles of commercially processed whole, two-percent, one-percent and nonfat milks with added solids as well as skim milk without added solids were measured using a rotational steady shear viscometer. Also tested were mixtures of concentrated skim milk added to skim milk over a range of 9.7% to 20.2% total solids. A shear rate range of 121 to 486 s^-1 was used with a cone and plate geometry. In all cases, linear plots of shear stress versus shear rate with small nonzero intercepts were obtained.     

INHIBITION OF LISTERIA MONOCYTOGENES AND OTHER BACTERIA BY A PLANT ESSENTIAL OIL (DMC) IN SPANISH SOFT CHEESE

The inhibitory effects of a mixture of plant essential oils (DMC) were tested in culture media and Spanish soft cheese. The minimum inhibitory concentration (MIC) was determined in plate count agar and tryptose broth, with pH adjusted to 6.5, against Listeria monocytogenes, Listeria innocua, Staphylococcus aureus, Lactobacillus brevis, Micrococcus luteus, Salmonella cholerasuis, Escherichia coli O157:H7 , Enterobacter cloacae, Pseudomonas aeruginosa and Pseudomonas fluorescens. The mixture of essential oils inhibited all Gram-positive bacteria tested at 40 ppm, but higher concentrations were needed to inhibit Gram-negative bacteria, and no inhibitory effect was found against Ps. fluorescens. The effects of DMC against L. monocytogenes and E. coli O157:H7 were evaluated in Spanish soft cheese (Queso Fresco, pH=6.5) stored at 7C. DMC had a bacteriostatic effect against L. monocytogenes at concentrations of 2500 ppm but was ineffective to control the growth of E. coli O157:H7 .     

“THERE'S NO PLACE LIKE NEW ORLEANS”: SENSE OF PLACE AND COMMUNITY RECOVERY IN THE NINTH WARD AFTER HURRICANE KATRINA

ABSTRACT: This study contributes to the literature on the strength of place attachment, identity, and dependence in low‐ and moderate‐income neighborhoods. It also engages the literature concerning the role of sense of place in community engagement and the disruption in place attachment, identity, and dependence that natural disasters can cause. By drawing on interview data collected from residents who returned to New Orleans after the storm and from former New Orleanians who evacuated to Houston but did not return, this article investigates the “sense of place” that residents in Ninth Ward New Orleans neighborhoods identify in their narratives about their pre‐ and post‐Hurricane Katrina experiences. The data considered here suggest that returning residents believe that New Orleans in general (and their Ninth Ward neighborhoods in particular) possess a unique bundle of characteristics that, when taken together, cannot be found or replicated elsewhere. While sense of place is an important motivator for returning residents, the data also suggest that complementary factors must be in place if the full potential of this social resource is to be realized.