An official website of the United States government
In each step of the cup game on n cups, a filler distributes up to 1" water among the cups, and then an emptier removes 1 unit of water from a single cup. The emptier’s goal is to minimize the height of the fullest cup, also known as the backlog. The cup emptying game has found extensive applications to processor scheduling, network- switch buffer management, quality of service guarantees, and data- structure deamortization. The greedy emptying algorithm (i.e., always remove from the fullest cup) is known to achieve backlog O(log n) and to be the optimal deterministic algorithm. Randomized algorithms can do significantly better, achieving backlog O(log log n) with high probability, as long as " is not too small. In order to achieve these improvements, the known randomized algorithms require that the filler is an oblivious adversary, unaware of which cups the emptier chooses to empty out of at each step. Such randomized guarantees are known to be impossible against fully adaptive fillers. We show that, even when the filler is just slightly non- adaptive, randomized emptying algorithms can still guarantee a backlog of O(log log n). In particular, we give randomized ran- domized algorithms against an elevated adaptive filler, which is an adaptive filler that can see the precise fills of every cup containing more than 3 units of water, but not of the cups containing less than 3 units.
more »
« less
Automated Handling and Feeding Techniques for Skewering Operations
Barbecue kebab skewers typically consist of various meat choices, including chicken, lamb, pork, or seafood, and vegetables such as onion and pepper. Traditionally, manual kebab-making is a time-consuming and labor-intensive process, which is considered to be replaced by semi-auto and full-auto skewering machines. Currently, semi-auto skewering machines still require two main manual preparation processes: align the small meat and vegetable pieces into lines for skewering operations; superpose the large pieces of meat and vegetables, then do skewering and cutting operations. Fully automated skewering machines also have two different strategies. The first one is to use rotating scrappers and cups with a respective depth to ensure only one item can be loaded into each cup. All the cups are arranged into sequential cup rows and cup lines for skewering operations. However, the cups are frequently left empty because the rotating scrapper design often blocks any items falling into cups. Thus, some processing facilities still need extra labor to manually fill these empty cups. Another solution is the pick-and-place method by using robot arms and real-time image processing equipment, which cannot process irregular food pieces, such as shrimps (C-shape). In this paper, a novel fully automated handling and feeding system has been developed to prepare and connect the skewering operations to establish unattended kebab production lines. The performances of singulation, handling, and feeding operations have been investigated with different parameter settings and food items. Besides, the presented machine system is the first realization of unattended kebab production lines to process shrimps (C-shape), and the first design of using horizontal skewering operation to produce meat and vegetable kebabs (cube+ square piece) and shrimp and vegetable kebabs (C-shape+ square piece). This study will be beneficial for developing more effective next-generation skewering technologies and better value-added meat and seafood products.
more »
« less
- Award ID(s):
- 2431189
- PAR ID:
- 10625021
- Publisher / Repository:
- American Society of Agricultural and Biological Engineers
- Date Published:
- Journal Name:
- Journal of the ASABE
- Volume:
- 67
- Issue:
- 5
- ISSN:
- 2769-3295
- Page Range / eLocation ID:
- 1181 to 1190
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Although vegetables are important for healthy diets, there are concerns about the sustainability of food systems that provide them. For example, half of fresh-market vegetables sold in the United States (US) are produced in California, leading to negative impacts associated with transportation. In Iowa, the focus of this study, 90% of food is imported from outside the state. Previous life cycle assessment (LCA) studies indicate that food consumption patterns affect global warming potential (GWP), with animal products having more negative impacts than vegetables. However, studies focused on how GWP, energy, and water use vary between food systems and vegetable types are less common. The purpose of this study was to examine these environmental impacts to inform decisions to buy locally or grow vegetables in the Midwest. We used a life cycle approach to examine three food systems (large-, mid-, and small-scale) and 18 vegetables commonly grown in/near Des Moines, Iowa. We found differences in GWP, energy, and water use (p ≤ 0.001 for each) for the three food systems with the large-scale scenario producing more emissions. There were also differences among vegetables, with the highest GWP for romaine lettuce (1.92 CO2eq/kg vegetable) approximately three times that of leaf lettuce (0.65 CO2eq/kg vegetable) at the large scale. Hotspots and tradeoffs between GWP, energy, and water use were also identified and could inform vegetable production/consumption based on carbon and water use footprints for the US Midwest.more » « less
-
Volatile organic compounds (VOCs) are common constituents of fruits, vegetables, and crops, and are closely associated with their quality attributes, such as firmness, sugar level, ripeness, translucency, and pungency levels. While VOCs are vital for assessing vegetable quality and phenotypic classification, traditional detection methods, such as Gas Chromatography-Mass Spectrometry (GC-MS) and Proton Transfer Reaction Mass Spectrometry (PTR-MS) are limited by expensive equipment, complex sample reparation, and slow turnaround time. Additionally, the transient nature of VOCs complicates their detection using these methods. Here, we developed a paper-based colorimetric sensor array combined with needles that could: 1) induce vegetable VOC release in a minimally invasive fashion, and 2) analyze VOCs in situ with a smartphone reader device. The needle sampling device helped release specific VOCs from the studied vegetables that usually require mechanic stimulation, while maintaining the vegetable viability. On the other hand, the colorimetric sensor array was optimized for sulfur compound-based VOCs with a limit of detection (LOD) in the 1–25 ppm range, and classified fourteen different vegetable VOCs, including sulfoxides, sulfides, mercaptans, thiophenes, and aldehydes. By combining principal components analysis (PCA) nalysis, the integrated sensor platform proficiently discriminated between four vegetable subtypes originating from two major categories within 2 min of testing time. Additionally, the sensor demomstrated the capability to distinguish between different types of tested fruits and vegetables, including garlic, green pepper, and nectarine. This rapid and minimally invasive sensing technology holds great promise for conducting field-based vegetable quality monitoring.more » « less
-
ABSTRACT The northern clingfish (Gobiesox maeandricus) has a suction-based adhesive disc that can stick to incredibly rough surfaces, a challenge for stiff commercial suction cups. Both clingfish discs and bioinspired suction cups have stiff cores but flexible edges that can deform to overcome surface irregularities. Compliant surfaces are common in nature and technical settings, but performance data for fish and commercial cups are gathered from stiff surfaces. We quantified the interaction between substrate compliance, surface roughness and suction performance for the northern clingfish, commercial suction cups and three biomimetic suction cups with disc rims of varying compliance. We found that all cups stick better on stiffer substrates and worse on more compliant ones, as indicated by peak stress values. On compliant substrates, surface roughness had little effect on adhesion, even for commercial cups that normally fail on hard, rough surfaces. We propose that suction performance on compliant substrates can be explained in part by effective elastic modulus, the combined elastic modulus from a cup–substrate interaction. Of all the tested cups, the biomimetic cups performed the best on compliant surfaces, highlighting their potential to be used in medical and marine geotechnical fields. Lastly, we discuss the overmolding technique used to generate the bioinspired cups and how it is an important tool for studying biology.more » « less
-
Bacteriophages are the most numerous entities on Earth. The number of sequenced phage genomes is approximately 8000 and increasing rapidly. Sequencing of a genome is followed by annotation, where genes, start codons, and functions are putatively identified. The mainstays of phage genome annotation are auto-annotation programs such as Glimmer and GeneMark. Due to the relatively small size of phage genomes, many groups choose to manually curate auto-annotation results to increase accuracy. An additional benefit of manual curation of auto-annotated phage genomes is that the process is amenable to be performed by students, and has been shown to improve student recruitment to the sciences. However, despite its greater accuracy and pedagogical value, manual curation suffers from high labor cost, lack of standardization and a degree of subjectivity in decision making, and susceptibility to mistakes. Here, we present a method developed in our lab that is designed to produce accurate annotations while reducing subjectivity and providing a degree of standardization in decision-making. We show that our method produces genome annotations more accurate than auto-annotation programs while retaining the pedagogical benefits of manual genome curation.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.13031/ja.15940
