基于Reduct的“规则+例外”学习

一般地说,机器学习关注的是“规则”,并将规则不能覆盖的“例外”考虑为噪声.然而,大量的应用不仅需要刻画满足大多数观察的规则,同时需要显现可解释地表示例外.在情报分析与安全预警这类应用中,例外可能是更为重要的知识.对此作者描述了一类限制在结构化符号数据集合上的基于Reduct的“规则+例外”学习的理论框架,并给出了解决这个框架各个组成部分中所存在的问题的一个方案.

Study on Serotypes and Auxotypes of Neisseria Gonorrhoeae in Guangzhou

Objective:To investigate the serotypes and auxotypes distribution of Neisseria gonorrhoeae in Guangzhou. Method: 131 strains of Neisseria gonorrhoeae wereserotyped by co-agglutination test and 108 strains wereauxotyped by La Scolea's method. Results: Out of 131 strains of Neisseria gonorrhoeae,87.8% (115/131) were WⅡ/WⅢ, while 9.9% (13/131) wereWⅠ. The most important auxotypes were Proto, Pro and ILe,42.6% (46/108), 21.3% (23/108) and 12.0%, respectively. WⅡ/WⅢ was distributed among the all auxotypes aboveand WI found only in both Proto and Pro. Conclusion: The study illustrated the prevailing serotype,WⅡ/WⅢ, and higher prevalence of Ile- in Guangzhou.

Changes of Circulating Platelet-Derived Growth Factor and Granulocyte Colony-Stimulating Factor in Patients with Condyloma Acuminatum

Objective: To study the expression levels of platelet-derived growth factor (PDGF) and granulocyte colony-stimulatingfactor (G-CSF) in peripheral blood and their role in thepathogenesis of Condyloma acuminatum (CA). Methods: Sera were taken from 70 patients with Condylomaacuminatum and compared with 35 healthy controls. PDGFand G-CSF in serum were quantitated using a dual antibodysandwich enzyme-linked immunoabsorbent assay (ELISA). Results: Serum concentrations of PDGF and G-CSF weresignificantly increased in patients with Condylomaacuminatum (CA) compared to controls (P<0.001 and P<0.005respectively). Serum levels of PDGF and G-CSF correlatedwith clinical severity of CA, but no significant difference wasobserved between different duration of disease groups. Asignificant positive correlation was noticed between neutrophilcount and G-CSF levels (γ=0.38, P<0.001), and the neutrophilcount showed no significant correlation with PDGE Conclusion: The results indicated that increased expressionof PDGF an -CSF in peripheral blood might be involved in pathogenesis of CA.

Soil Properties Degradation Assessment Using Infrared Scanning Technique of Soils （Case Study： Eastern of Congo）

Recently, near infrared reflectance （NIR） and mid-infrared （MIR） spectroscopy techniques are increasingly introduced as convenient and simple non-destructive techniques for quantifying several soil properties. This study uses MIR method to predict pH, soil organic C, total N, AI, Ca, Mg and K, CEC and soil texture for soil samples collected in Sud-Kivu, Congo. A total of 536 composite soil samples were taken from two locations （Burhale and Luhihi） at two depths （0-20 cm and 20-40 cm） using a spatially-stratified random sampling design within an area of 200 km2. Differences in characteristics were evaluated between the two locations, land use （cultivated vs. non-cultivated land） with soil depths. A random subset of the samples （10%） were analyzed using standard wet chemistry methods, and calibration models developed by MIR data to estimate soil properties for the full soil sample set. Partial least squares regression （PLS） method gave acceptable coefficients of determination between 0.71 and 0.93 for all parameters. Soil organic matter levels were higher in cultivated plots in Luhihi （3.9% C） than in Burhale （3.0% C）, suggesting lower levels of soil fertility in the later area. This indicates high levels of acidity, which are likely to limit crop production in the area. Phosphorus deficiency is acute in Burhale （2.4 mg P/kg） but less in Luhihi （5.4 mg P/kg）. In both locations, low levels of Ca and Mg indicate that soils may be susceptible to deficiencies in both elements.These findings provide new opportunities for monitoring soil quality in the region which can benefit multiple actors and scientists involved in the agricultural and environmental sectors.

Epidemiological characteristics of expressway traffic trauma in 2040 cases

Objective: To evaluate the epidemiologic characteristics of expressway traffic trauma in (2 040) cases in Zhejiang Province.Methods: The data of (2 040) cases of expressway traffic trauma taken from Zhejiang Provincial Expressway Traffic Bureau were analyzed with computer techniques.Results: A total of (2 040) persons were injured in (7 963) expressway traffic accidents in Zhejiang Province from January 1999 to December 2001. Among them, 435 persons died (mortality, (21.3)%) and 1 605 were injured. The economic losses were over 170 million yuan RMB. The accidents caused by human factors accounted for (84.9)% (vehicle drivers accounting for (79.2)%), which mainly included improper measures ((20.4)%), steering failure ((17.7)%), insufficient longitudinal space ((15.9)%), over-speed drive ((12.5)%), fatigue drive ((6.4)%), loading violation ((5.9)%) and careless drive ((6.3)%). Mechanical troubles and other factors took up (15.1)%. There existed obvious uneven distribution among various regions. Jiaxing and Shaoxing were the sections with high incidence of accidents. The accidents mostly happened at 12:00-18:00, but the causing-dead ones most concentrated at 0:00-6:00. The main victims were young and middle-aged people (accounting for (72.3)%), but accident-stricken children and elderly persons (over 70 years old) took up higher mortalities ((30.2)% and (40.7)%, respectively). Conclusions: The number of expressway traffic accidents and the economic losses are increasing year by year, with obvious uneven distribution at different places, different time and under different weather conditions. To reduce the accident frequency, it is important to strengthen the enforcement of traffic regulation, to balance the system of ”person-vehicle-road”, and to improve the safety consciousness of people.