Seize the (intra)day: Features selection and rules extraction for tradings on high-frequency data

We describe a method to develop trading rules based on the responses of self-organizing maps (SOMs), trained under various distance metrics. The effectiveness of the procedure is examined on 5 min data of S&P MIB financial index, and its performances compared with those of classical buy and hold trading technique. The noticeable innovations of the paper include the methodology itself, which brings SOMs into a decision making tool to operate into the market; the focus on intraday tradings bars; the systematic study of how changes in the distance metrics employed to train the maps may affect the overall performances, and, finally, the discussion of system performances both in the absence and in the presence of commission fees. At the current stage the results, evaluated with both financial and statistical indicators, bring us to the following conclusions: (a) self-organizing maps can be helpful to localize profitable intraday patterns, achieving more stable performances than common trading rules; (b) working with proper metrics may enhance the overall performances; (c) trading strategies based on unsupervised neural networks make exploitable with profits almost continuous trades, until commission fees maintain below suitable thresholds.     

欧洲PCB行业的供应链面临萎缩

主要论述由于世界原材料涨价和价格竞争等原因,欧洲PCB行业供应链面临萎缩。     

Statement on report of Joint Commission on Mental Illness and Health.

An "endorsement of Action for Mental Health [see 35: 6705], the final report of the Joint Commission on Mental Illness and Health." The report cites the very substantial cost of adequate care for mental patients, hidden costs of mental illness, gross inadequacy of present measures, and presents a pattern of increased federal financial support to deal with the problem. It recommends the demise of the large custodial "mental hospital" and calls for "invention and trial of novel approaches." Reservations about the report are also made explicit: the report emphasized improved treatment of mental illness at the expense of other facets of the problem area; it says little about promoting more effective personal development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

中国联通社会渠道发展之路

通过研究电信运营商目前的社会渠道发展现状,对比分析运营商之间的竞争态势,提出中国联通在社会渠道方面的发展策略建议,为联通公司下一步的渠道发展提供参考。     

近代东方的“中世纪欧洲城市”——澳门

澳门,这个孤悬海外的弹丸之地,本无任何资源或文化上的优势可言;澳门,这个近代移植于西方的中世纪胚胎,本无任何孕育成长的生机可望.然而,澳门奇迹般地生存与发展,使我们得到一个极其罕见的例证,去探索原本在时间、空间和性质上差异极大的城市文明之间的和谐共存.     

Trace-metal contamination in proton exchange membrane fuel cells caused by laser-cutting stains on carbon-coated metallic bipolar plates

Trace-metal contamination poses a threat to performance and stability of proton exchange membrane fuel cells (PEMFCs). In this study the source of origin and degree of metal dissolution from carbon-coated 316L bipolar plates (BPPs) are evaluated after a long-term PEMFC test run under conditions resembling a real-life automotive application. Despite intact carbon-coating, metal dissolution occurs from uncoated oxycarbide stains on the plates’ surface. Which correlates with post-mortem detection of chromium, iron and nickel in the membrane electrode assembly. The rate of cell voltage decrease throughout the high current operations is found to be twice as high in the presence of metal ions. Metal dissolution can be correlated with transients in cell voltage during dynamic current load cycling as a result of temporary global fuel starvation. The observed difference in metal dissolution on the anode and cathode BPP indicates weak galvanic coupling between the bipolar plate(s) and the electrode layer(s).     

Occurrence and estimation of aflatoxin M1 exposure in milk in Serbia

The occurrence of AFM1 was investigated in 150 cow's, 10 goat's, 5 donkey's, 10 breasts milk and 1 infant formula samples. Analyses were done using Enzyme Linked Immunosorbent Assay (ELISA) method. AFM1 was detected in 98.7% of analyzed cow's milk samples in concentrations ranged from 0.01 to 1.2 μg/kg. Further, even 129 (86.0%) cow's milk samples contained AFM1 in concentration greater than maximum residue levels (MRL) of 0.05 μg/kg defined by European Union (EU) Regulation. Analysis of other types of milk showed that AFM1 was detected in 80.0% goat's, 60.0% donkey's and 60.0% of breasts milk samples.Although Serbian Regulation for MRL of AFM1 in milk has been changed and harmonized with EU Regulation in 2011, occurrence of AFM1 in milk in Serbia during 2013 resulted in Regulation changes, and MRL were changed from 0.05 to 0.5 μg/kg.On the basis of the obtained concentrations of the AFM1 in cow's milk, collected information about average milk intake and mean body weight (bw) for different age's categories, mean ingestion of AFM1 in ng/kg per bw per day were estimated. Obtained results showed that all age's categories, especially children, are exposed with high risk related to presence of AFM1 in milk.There are only a few published data about occurrence of AFM1 in milk in Serbia and none about intake assessment for AFM1.     

HACCP – The difficulty with Hazard Analysis

HACCP is a key element of modern food safety management practice such that design, implementation, control and management of HACCP systems are crucial to the production of safe food products. Whilst it is widely accepted that food companies should apply HACCP, understanding of the factors impacting successful HACCP application is limited and this knowledge is important to the delivery of systems that will control all relevant food safety hazards. HACCP principle 1, Conduct a Hazard Analysis, forms a central pillar of any HACCP plan since hazards need to be identified, analysed and understood before effective control measures can be specified. However limited guidance is available to HACCP teams on exactly how to approach the application of this principle. This paper discusses an investigation into the application of HACCP principle 1 by HACCP teams operating within manufacturing sites of a multinational food company. Using a combination of HACCP knowledge testing and HACCP plan assessment, the study identified weaknesses in knowledge of significant hazard identification and errors in the hazard analysis process, including errors in application of structured risk evaluation methods. Findings suggest that this is an area of difficulty for HACCP teams and that further detailed guidance in the application of this HACCP principle is urgently needed.     

The precautionary principle and other non-tariff barriers to free and fair international food trade

International food trade and world population are growing rapidly. National legislation has been enacted and implemented in many countries to assure good quality and safe foods to meet increased demand. No country is fully self-sufficient in domestic food production to meet population demands, and all require some food imports. Current international food trade agreements call for free and fair food trade between all countries, developed and developing. National food legislation and food production, processing and marketing systems have evolved in most countries to ensure better quality and safer foods. At the international level the work of the FAO/ WHO Codex Alimentarius Commission (Codex) and the World Trade Organization Agreements on Sanitary and Phytosanitary Measures (SPS) and on Technical Barriers to Trade (TBT) and related Uruguay Round agreements have been agreed to by over 140 countries with the aim to promoting the free and fair trade of good quality and safe foods between all countries. The SPS and TBT agreements rely on science-based Codex standards, guidelines, and recommendations as benchmarks for judging international food trade disputes. A number of non-tariff barriers to trade, often related to agricultural subsidies and other food trade payments in developed countries, continue to give rise to complaints to WTO. They also continue to prevent free and fair trade, particularly for developing countries in international food trade. A number of these non-tariff barriers to trade are briefly examined, along with other domestic and international food trade problems, and recommendations for improvements are made.     

食品和饲料中农药残留分析方法性能标准指南

本文译自国际食品法典委员会"CAC/GL 90-2017食品和饲料中农药残留分析方法性能标准指南".该指南规定了农药残留分析方法的选择和验证原则、分析方法的性能参数、筛选方法的性能指标、定量方法的性能指标、分析物鉴定方法和确证方法的性能标准和定义等.本译文可为我国食品和饲料中农药残留分析专业人员研发和验证化学分析方法或...