海关商品HS编码分类是企业和个人进出口贸易的重要国际程序。HS编码分类可以看作是一个文本分类问题,即给定一段商品的描述,确定商品由HS编码表示的所属类别。然而,该任务比一般的文本分类任务更具挑战性,原因是商品描述文本具有特定的...海关商品HS编码分类是企业和个人进出口贸易的重要国际程序。HS编码分类可以看作是一个文本分类问题,即给定一段商品的描述,确定商品由HS编码表示的所属类别。然而,该任务比一般的文本分类任务更具挑战性,原因是商品描述文本具有特定的层次结构,同时商品描述文本展现出了两个层次上的序列特征,并且商品描述文本还存在关键信息分散且描述形式多样的特点。现有的文本分类方法无法综合考虑以上因素来捕获商品描述文本中的关键信息。对此,文中提出了一种融合文本序列和图信息的神经网络(Text Sequence and Graph Information combination Neural Network,TSGINN)模型,用于解决海关商品HS编码分类问题。TSGINN将HS编码分类问题定义为基于词共现网络的子图分类问题,通过图注意力网络建模非连续词之间的关联关系,同时利用分层的长短期记忆网络结合商品文本层次结构捕获多层次的序列信息。在真实海关商品数据集上进行了实验,结果表明TSGINN模型的HS编码分类效果优于其他分类方法。展开更多
Short-chain and medium-chain chlorinated paraffins(SCCPs/MCCPs)are of concern due to their persistence,bioaccumulation,and toxicity.SCCPs were listed in 2017 as persistent organic pollutants(POPs)in the Stockholm Conv...Short-chain and medium-chain chlorinated paraffins(SCCPs/MCCPs)are of concern due to their persistence,bioaccumulation,and toxicity.SCCPs were listed in 2017 as persistent organic pollutants(POPs)in the Stockholm Convention and Rotterdam Convention for Prior Informed Consent(PIC)procedure.MCCPs are evaluated in the POPs Reviewing Committee for listing.Studies in Africa demonstrate high SCCP/MCCP levels in house dust and human milk.Therefore,this study undertook an initial assessment of the production and import situation in Nigeria.The Nigerian government has not assessed SCCPs yet and has no registered exemptions for SCCPs and therefore should not produce or use SCCPs.Also,Nigeria has not notified Rotterdam Convention of PIC procedure and,therefore,no SCCP should be imported into Nigeria.Since no local production of SCCPs/MCCPs was observed in Nigeria,this study therefore compiled data on importation of SCCPs/MCCPs and products which may likely contain these chemicals from the UN Comtrade Database for the period 1996 to 2018.Despite the listing of SCCPs in the Rotterdam Convention,there is still no specific Harmonized System(HS)codes for SCCPs/MCCPs.This study therefore used HS codes of product categories known to contain SCCPs/MCCPs.HS substance categories under which SCCP/MCCPs are usually imported include plasticisers and other product categories that amounted to 229,779 and 518,342 tonnes respectively but without specific information on the type of plasticiser.About 39%of PVC and rubber imports of 2,683,015 tonnes and 3,516,052 tonnes respectively contain plasticisers.Based on the SCCP and MCCP impact factors from literature for China,the highest amount of SCCP(33,712 tonnes)was imported in the different PVC products while rubber products accounted to 1386 tonnes and PUR foam to 2331 tonnes.The amount of imported MCCPs in PVC products(25,599 tonnes)and rubber products(32,317 tonnes)was in the same order of magnitude while MCCP imported in PUR foam was estimated to 2020 tonnes.At the end of life(EoL),these product categories most likely contain appreciable amount of SCCPs possibly above Basel Convention low POP limit.This will hamper recycling and circular economy for these waste categories and generate POPs stockpiles/wastes that are difficult to manage/destroy in Africa.Hence there is an urgent need for specific HS Codes for SCCPs and industrial POPs currently produced/used for better control.Presently,products containing SCCPs are not labelled and are imported in huge quantities into Nigeria,without monitoring.In its current form this rather conveys a pseudo-safety for industrial POPs that do not exist.The Rotterdam Convention needs to establish specific HS codes for POPs for an appropriate PIC procedure and effective control of industrial POPs still produced.Furthermore,products containing SCCPs(and other POPs)require labelling and should also be covered under the Rotterdam Convention.The study highlights that Nigeria should urgently update the NIP for chemicals listed from 2015 to 2019 with a detailed SCCP inventory and develop monitoring capacity for market surveys.The Rotterdam Convention does not function fully and need to significantly improve to assure PIC procedure.展开更多
文摘海关商品HS编码分类是企业和个人进出口贸易的重要国际程序。HS编码分类可以看作是一个文本分类问题,即给定一段商品的描述,确定商品由HS编码表示的所属类别。然而,该任务比一般的文本分类任务更具挑战性,原因是商品描述文本具有特定的层次结构,同时商品描述文本展现出了两个层次上的序列特征,并且商品描述文本还存在关键信息分散且描述形式多样的特点。现有的文本分类方法无法综合考虑以上因素来捕获商品描述文本中的关键信息。对此,文中提出了一种融合文本序列和图信息的神经网络(Text Sequence and Graph Information combination Neural Network,TSGINN)模型,用于解决海关商品HS编码分类问题。TSGINN将HS编码分类问题定义为基于词共现网络的子图分类问题,通过图注意力网络建模非连续词之间的关联关系,同时利用分层的长短期记忆网络结合商品文本层次结构捕获多层次的序列信息。在真实海关商品数据集上进行了实验,结果表明TSGINN模型的HS编码分类效果优于其他分类方法。
文摘Short-chain and medium-chain chlorinated paraffins(SCCPs/MCCPs)are of concern due to their persistence,bioaccumulation,and toxicity.SCCPs were listed in 2017 as persistent organic pollutants(POPs)in the Stockholm Convention and Rotterdam Convention for Prior Informed Consent(PIC)procedure.MCCPs are evaluated in the POPs Reviewing Committee for listing.Studies in Africa demonstrate high SCCP/MCCP levels in house dust and human milk.Therefore,this study undertook an initial assessment of the production and import situation in Nigeria.The Nigerian government has not assessed SCCPs yet and has no registered exemptions for SCCPs and therefore should not produce or use SCCPs.Also,Nigeria has not notified Rotterdam Convention of PIC procedure and,therefore,no SCCP should be imported into Nigeria.Since no local production of SCCPs/MCCPs was observed in Nigeria,this study therefore compiled data on importation of SCCPs/MCCPs and products which may likely contain these chemicals from the UN Comtrade Database for the period 1996 to 2018.Despite the listing of SCCPs in the Rotterdam Convention,there is still no specific Harmonized System(HS)codes for SCCPs/MCCPs.This study therefore used HS codes of product categories known to contain SCCPs/MCCPs.HS substance categories under which SCCP/MCCPs are usually imported include plasticisers and other product categories that amounted to 229,779 and 518,342 tonnes respectively but without specific information on the type of plasticiser.About 39%of PVC and rubber imports of 2,683,015 tonnes and 3,516,052 tonnes respectively contain plasticisers.Based on the SCCP and MCCP impact factors from literature for China,the highest amount of SCCP(33,712 tonnes)was imported in the different PVC products while rubber products accounted to 1386 tonnes and PUR foam to 2331 tonnes.The amount of imported MCCPs in PVC products(25,599 tonnes)and rubber products(32,317 tonnes)was in the same order of magnitude while MCCP imported in PUR foam was estimated to 2020 tonnes.At the end of life(EoL),these product categories most likely contain appreciable amount of SCCPs possibly above Basel Convention low POP limit.This will hamper recycling and circular economy for these waste categories and generate POPs stockpiles/wastes that are difficult to manage/destroy in Africa.Hence there is an urgent need for specific HS Codes for SCCPs and industrial POPs currently produced/used for better control.Presently,products containing SCCPs are not labelled and are imported in huge quantities into Nigeria,without monitoring.In its current form this rather conveys a pseudo-safety for industrial POPs that do not exist.The Rotterdam Convention needs to establish specific HS codes for POPs for an appropriate PIC procedure and effective control of industrial POPs still produced.Furthermore,products containing SCCPs(and other POPs)require labelling and should also be covered under the Rotterdam Convention.The study highlights that Nigeria should urgently update the NIP for chemicals listed from 2015 to 2019 with a detailed SCCP inventory and develop monitoring capacity for market surveys.The Rotterdam Convention does not function fully and need to significantly improve to assure PIC procedure.
