Transfer learning between crop types for semantic segmentation of crops versus weeds in precision agriculture

Agricultural robots rely on semantic segmentation for distinguishing between crops and weeds to perform selective treatments and increase yield and crop health while reducing the amount of chemicals used. Deep‐learning approaches have recently achieved both excellent classification performance and real‐time execution. However, these techniques also rely on a large amount of training data, requiring a substantial labeling effort, both of which are scarce in precision agriculture. Additional design efforts are required to achieve commercially viable performance levels under varying environmental conditions and crop growth stages. In this paper, we explore the role of knowledge transfer between deep‐learning‐based classifiers for different crop types, with the goal of reducing the retraining time and labeling efforts required for a new crop. We examine the classification performance on three datasets with different crop types and containing a variety of weeds and compare the performance and retraining efforts required when using data labeled at pixel level with partially labeled data obtained through a less time‐consuming procedure of annotating the segmentation output. We show that transfer learning between different crop types is possible and reduces training times for up to 80%. Furthermore, we show that even when the data used for retraining are imperfectly annotated, the classification performance is within 2% of that of networks trained with laboriously annotated pixel‐precision data.     

Creative clusters in the regeneration of Valletta and the cultural politics of Strait Street

The paper aims to unfold the narrative of development in a creative cluster project for the regeneration of Strait Street in Valletta, Malta. This is approached by first examining the distinctive, historically contentious background of the neighbourhood and, thereafter, unpacking the development narrative of policy documents and the discursive and material constructs about the creative city approach to regeneration strategies in the city. Using a ‘system-wide’ analytical framework, this material is then scrutinized to gain an understanding of the specificities involved and, finally, discuss the crucial features of the key dimensions elucidating the potential strengths and weaknesses of the case     

Moving beyond ‘more crop per drop’: insights from two decades of research on agricultural water productivity

ABSTRACT

Concern over increasing water scarcity has led to the introduction of the concept of agricultural water productivity and an emphasis on interventions to achieve ‘more crop per drop’. Yet, a strong debate continues on how the concept is to be defined and used. Drawing largely from the irrigation literature, the origins of the concept and its methodological developments are reviewed, and its use in applied work over two decades is discussed. Based on this analysis of conceptual and applied research, key insights into the concept’s contributions and limitations are presented, as well as opportunities for further refinements.     

莫高窟第61窟《回鹘女供养人》文创设计研究

目的针对社会文创设计出现的两种典型误区,以敦煌莫高窟第61窟女供养人文创设计为例进行设计研究实践,梳理出传统视觉形象的研究方法和创新设计方法,以此传承和保护中国传统文化。方法采用“图解法”对莫高窟第61窟东壁南侧女供养人的人物身份、妆容、发饰、服饰、色彩、局部等进行深入剖析,并将其作为文创衍生设计的根本来源,总结适用于当今社会的传统文化视觉元素创新设计方法,实现以传统文化为本源、艺术设计为手段、文创设计为载体的传统文化现代设计转译。结论依据“图解法”完成文创衍生设计,实现传统文化与现代设计的深度融合,有助于为不同传统文化题材的文创设计提供借鉴之意。     

基于秩序与非秩序理论的文创产品卡通形象设计研究

目的 从秩序与非秩序理论出发,研究文创产品卡通形象的设计方法.方法 对秩序与非秩序理论的视觉机制和创制理论进行梳理,结合实例,阐述了其与文创产品卡通形象设计之间的联系,分析文创产品卡通形象中的秩序与非秩序的表现形式,提出基于秩序与非秩序理论文创产品卡通形象设计的主要原则,归纳出一套基于秩序与非秩序理论的文创产品卡通形象设计流程与方法,指导设计实践,并验证这些理论方法在设计实践中有效性与可行性.结论 通过对秩序与非秩序理论的研究,文创产品卡通形象设计时应注意提高辨识度、亲和力和便于衍生设计的原则.探索基于秩序与非秩序理论的设计流程与方法,按照界定主题、主体形象设计、主体形象拓展、衍生品应用四个环节开展整体方案设计,为文创产品卡通形象设计提供新的思路与方法.     

基于虚拟导航线的农业机器人精确视觉导航方法

针对农田、野外环境中无人工标记情况下的导航问题，提出了一种基于虚拟导航线的农业机器人精确视觉导航方法。该方法不需要铺设导航线或者路标即可引导机器人行走直线。首先，根据需求确定需要跟踪的目标区域，之后控制机器人调整方向直到目标移至视野中央；其次，根据机器人和目标的位置确定参照目标，并依据两个目标的位置确定虚拟导航线；然后，动态更新导航线，并结合虚拟定标线和虚拟导航线确定偏移角度和偏移距离；最后，利用偏移参数构建模糊控制表，并以此实现对机器人旋转角度和行走速度的调整。实验结果表明，该算法能较为精确地实现对导航路线的识别，进而利用模糊控制策略使机器人沿直线向目标行走，且导航精度在10 cm以内。     

Worldwide aflatoxin contamination of agricultural products and foods: From occurrence to control

Aflatoxins represent a global public health and economic concern as they are responsible for significant adverse health and economic issues affecting consumers and farmers worldwide. Produced by fungal species from the Aspergillus genus, aflatoxins are a toxic, mutagenic, and carcinogenic group of fungal metabolites that routinely contaminate food and agricultural products. Climate and diet are essential factors in the aflatoxin contamination of food and subsequent human exposure process. Countri es with warmer climates and staple foods that are aflatoxin-susceptible shoulder a substantial portion of the global aflatoxins burden. Enactment of regulations, prevention of pre- and postharvest contamination, decontamination, and detoxification have been used to prevent human dietary exposure to aflatoxin. Exploiting their chemical and structural properties, means are devised to detect and quantify aflatoxin presence in foods. Herein, recent developments in several important aspects impacting aflatoxin contamination of the food supply, including: fungal producers of the toxin, occurrence in food, worldwide regulations, detection methods, preventive strategies, and removal and degradation methods were reviewed and presented. In conclusion, aflatoxin continues to be a major food safety problem, especially in developing countries where regulatory limits do not exist or are not adequately enforced. Finally, knowledge gaps and current challenges in each discussed aspect were identified, and new solutions were proposed.     

Tropane alkaloid contamination of agricultural commodities and food products in relation to consumer health: Learnings from the 2019 Uganda food aid outbreak

Tropane alkaloids (TAs) are secondary plant metabolites derived mainly from Solanaceae plant families, with the most virulent invasive species being Datura stramonium. Datura stramonium commonly grows in cereal fields and produce TAs (e.g., hyoscyamine and scopolamine) which may accidentally contaminate cereals (and cereal-based foods) at occasionally high levels. Dietary exposure to TAs can be toxic and depending on the dose ingested can cause outcomes ranging from anticholinergic effects to acute poisoning and death. In 2019, 315 adults became ill and another five adults died in Uganda following consumption of a “Super Cereal” (a fortified blended food) that was later confirmed to be contaminated by TAs—a scenario which provoked this holistic review on TAs in foodstuffs. Thus, this article provides information on the history, development, occurrences, exposures, and human legislative and health benchmarks for TAs. It describes control strategies for reducing TA contamination of agricultural commodities and resultant health implications following consumption of TA contaminated foodstuffs. Adequate application of food safety control measures (including maximum limits) and good practices, from the start of cereal cultivation through to the final stages of manufacturing of food products can aid in the reduction of seeing toxic plants including D. stramonium in cereal fields.     

基于津沽文化脉络的文创产品创新发展策略研究

类比故宫博物院等优秀文创产品产业化发展思路对津沽文化脉络进行文化传承元素的有效梳理，结合产业化发展的活态传承与保护形式，以文创产品设计为研究载体，带动城市文化创新发展与文化自信，间接促进社会经济发展。通过总结天津非物质文化遗产的特性和产业化发展现状，对比分析不同领域文创产品设计案例。以市场需求定位设计层级，建立在设计层级基础上的产品创新设计理念，从升级保护技术的角度拓展产业化发展思路，结合数字化营销模式，适应现今智能化时代需求。总结了非遗文创产品在层级设计指导下的历史与文化，以及在现代与未来概念下的文化传承创新发展方向。进一步带动了天津文化产业发展，促进文化产业的良性循环，为天津传统文化产业化发展提出了切实可行的创新理念。     

浅谈农业科研档案管理存在的问题及建议

基于当前农业科研档案管理的概况,其中存在着一些问题和不足。通过分析这些问题,进而提出针对性的解决对策和建议,进一步提高农业科研档案管理效率,为各项工作开展提供更好的保障。