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152. Empty Container Repositioning

Author

Santén, Vendela, Altuntas Vural, Ceren, Castrellon, Juan Pablo, Rogerson, Sara, Roso, Violeta, Sanchez-Diaz, Ivan, Santén, Vendela, Altuntas Vural, Ceren, Castrellon, Juan Pablo, Rogerson, Sara, Roso, Violeta, and Sanchez-Diaz, Ivan

Abstract

Although some movements of empty containers are needed due to imbalances between inbound and outbound goods flows in specific geographical areas, the transport of empty containers could be performed more efficiently. This report outlines results from the project “Increasing transport efficiency through reducing positioning of empty containers” performed during 2020-2023 by RISE and Chalmers, and financed by the Swedish Energy Agency. The purpose of the project was to contribute to increasing transport efficiency by understanding how empty container repositioning can be reduced and made more efficient in the Swedish transport system. To provide increased understanding regarding current practices and possible improvement areas, the report describes empty repositioning of containers in the inland container transport, and highlights drivers and barriers to minimize and make empty repositioning more efficient. Data on empty container movements in ports and by truck provide increased understanding of the current state. However, available data only offer partial views of empty container movements. Therefore, an empty trip model was constructed to help understand the proportion of containers that are transported empty between various origin-destination pairs, drawing on the Swedish road goods transport data from Trafikanalys. Several recommendations are made for how to improve data on empty container movements, for example differentiating between 20 and 40 feet containers. Also, this report details strategies for either reducing the empty container repositioning or making it more efficient within the national transport system, with a focus on: a) increased reutilization of containers and b) an increased share of rail compared to truck transport. Reutilization involves matching import and export containers to a larger degree, for example facilitated by extended storage of containers, and also how demands in various regions can be matched more efficiently, where some geograph

Published
2023

153. Bridging the logistics divide with service inclusion for socially sustainable urban logistics services.

Author

Vural, Ceren Altuntas, Sanchez-Diaz, Ivan, Halldórsson, Árni, and Ait, Linda-Triin

Subjects
MATHEMATICAL logic, COVID-19 pandemic, LOGISTICS, SOCIAL sustainability, SUSTAINABLE development
Abstract

The rise of e-commerce over the last decade has increased the pressure on urban logistics and highlighted important sustainability challenges. The COVID-19 pandemic exacerbated this trend and underscored the need to address social sustainability challenges with e-commerce. In particular, the pandemic drew attention to the uneven access to home deliveries and the importance of having a logistic system that is aligned with the principles underlying society and sustainable development goals. The purpose of this paper is to identify urban logistics services that emerged in response to access limitations linked to the COVID-19 pandemic, and to analyse how these services can enhance inclusivity and fair access to goods. We adopt an exploratory and qualitative research design based on a deductive content analysis approach. This method aims to systematize, objectively analyse, and draw assumptions from secondary evidence and semi-structured interviews with key actors. We identified several urban logistics innovations that spanned organizational, transportation modal shift, informational and technological approaches to face existing restrictions. The findings indicate a deficiency in inclusivity and equitable access to logistics innovations, prompting ad-hoc organization by citizens and private initiatives in response to the extraordinary circumstances of the pandemic. We introduced the concept of logistics divide to analyse the inequalities on who benefits from logistics innovations. This divide is a consequence of the uneven ability of different consumer segments to get access to those services either due to digital mastery, geographical barriers, legal barriers, or to economic reasons. The findings also showed that urban logistics actors have started to innovate to increase access to goods after the pandemic disclosed this logistics divide. In essence, this paper shows the importance of integrating transport and logistics research with transformative service research to decrease the logistics divide and achieve more equitable urban logistics. [ABSTRACT FROM AUTHOR]

Published
2024
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154. Seeking equity and justice in urban freight: where to look?

Author

Fried, Travis, Goodchild, Anne, Browne, Michael, and Sanchez-Diaz, Ivan

Subjects
JUSTICE, DELIVERY of goods, URBAN research, CITIES & towns, RESEARCH personnel
Abstract

Urban freight systems embed and reflect spatial inequities in cities and imbalanced power structures within transport decision-making. These concerns are principal domains of "transportation justice" (TJ) and "mobility justice" (MJ) scholarship that have emerged in the past decade. However, little research exists situating urban freight within these prevailing frameworks, which leaves urban freight research on socio-environmental equity and justice ill-defined, especially compared to passenger or personal mobility discussions. Through the lens that derives from TJ and MJ's critical dialogue, this study synthesises urban freight literature's engagement with equity and justice. Namely, the review evaluates: How do researchers identify equitable distributions of urban freight's costs and benefits? At what scale do researchers evaluate urban freight inequities? And who does research consider entitled to urban freight equity and how are they involved in urban freight governance? The findings help inform researchers who seek to reimagine urban freight management strategies within broader equity and justice discourse. [ABSTRACT FROM AUTHOR]

Published
2024
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162. Efficiently transporting average treatment effects using a sufficient subset of effect modifiers

Author

Rudolph, Kara E., Williams, Nicholas T., Stuart, Elizabeth A., and Diaz, Ivan

Subjects
Methodology (stat.ME), FOS: Computer and information sciences, Statistics - Methodology
Abstract

We develop flexible and nonparametric estimators of the average treatment effect (ATE) transported to a new population that offer potential efficiency gains by incorporating only a sufficient subset of effect modifiers that are differentially distributed between the source and target populations into the transport step. We develop both a one-step estimator when this sufficient subset of effect modifiers is known and a collaborative one-step estimator when it is unknown. We discuss when we would expect our estimators to be more efficient than those that assume all covariates may be relevant effect modifiers and the exceptions when we would expect worse efficiency. We use simulation to compare finite sample performance across our proposed estimators and existing estimators of the transported ATE, including in the presence of practical violations of the positivity assumption. Lastly, we apply our proposed estimators to a large-scale housing trial.

Published
2023

163. An end-to-end SE(3)-equivariant segmentation network

Author

Diaz, Ivan, Geiger, Mario, and McKinley, Richard Iain

Subjects
FOS: Computer and information sciences, Computer Science - Machine Learning, Computer Vision and Pattern Recognition (cs.CV), Image and Video Processing (eess.IV), FOS: Electrical engineering, electronic engineering, information engineering, Computer Science - Computer Vision and Pattern Recognition, Electrical Engineering and Systems Science - Image and Video Processing, Machine Learning (cs.LG)
Abstract

Convolutional neural networks (CNNs) allow for parameter sharing and translational equivariance by using convolutional kernels in their linear layers. By restricting these kernels to be SO(3)-steerable, CNNs can further improve parameter sharing and equivariance. These equivariant convolutional layers have several advantages over standard convolutional layers, including increased robustness to unseen poses, smaller network size, and improved sample efficiency. Despite this, most segmentation networks used in medical image analysis continue to rely on standard convolutional kernels. In this paper, we present a new family of segmentation networks that use equivariant voxel convolutions based on spherical harmonics, as well as equivariant pooling and normalization operations. These SE(3)-equivariant volumetric segmentation networks, which are robust to data poses not seen during training, do not require rotation-based data augmentation during training. In addition, we demonstrate improved segmentation performance in MRI brain tumor and healthy brain structure segmentation tasks, with enhanced robustness to reduced amounts of training data and improved parameter efficiency. Code to reproduce our results, and to implement the equivariant segmentation networks for other tasks is available at http://github.com/SCAN-NRAD/e3nn_Unet, 19 pages, 10 figures, submitted to the Journal of Machine Learning for Biomedical Imaging

Published
2023

174. Ontological Configuration Management for Wireless Mesh Routers

Author

Díaz, Iván, Popi, Cristian, Festor, Olivier, Touriño, Juan, Doallo, Ramón, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Nunzi, Giorgio, editor, Scoglio, Caterina, editor, and Li, Xing, editor

Published
2009
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179. Towards Low-Latency Model-Oriented Distributed Systems Management

Author

Díaz, Iván, Touriño, Juan, Doallo, Ramón, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Ata, Shingo, editor, and Hong, Choong Seon, editor

Published
2007
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183. The Effect of Morphological Instruction in Improving the Spelling, Vocabulary, and Reading Comprehension of High School English Language Learners (ELLs)

Author

Diaz, Ivan

Abstract

The purpose of this study was to determine if Morphological Instruction (knowledge of the Germanic, Latin, and Greek words, roots, and affixes of English) was an effective instructional approach towards accelerating the acquisition of spelling, vocabulary, and reading comprehension and closing at least a 6,000 word gap between English language learners and their English dominant peers. Studies show that there exists a gap between English dominant high school students who bring 10-12,000 words to reading instruction as opposed to the 5,000-7000 words of English Language Learners (ELLs) (Hart & Risley, 1995; Biemiller & Slonim, 2001). For many ELLs, this gap has resulted in school failure, higher dropout rates, and dead-end careers (Fleishman, 2004). One possibility for closing this gap is "Morphological Instruction" which can provide learners with expansive knowledge of the Germanic, Latin, and Greek words, roots, and affixes of English. This knowledge can help students acquire meanings of unfamiliar, morphologically complex words and expose them to the structure of English from a cross-language perspective through structural linguistic elements that have rarely been included in the current language arts or English curriculum (Fashola, Drum, Mayer & Kang, 1996). From early elementary grades and continuing into the college years, a major reason for Morphological Instruction in English, when included in the curriculum, has been to increase knowledge of high-level vocabulary that is essential for comprehension of text (Carlo et al., 2004). In addition, Morphological Instruction, with its focus on affixing, may result in spelling improvement and increased decoding ability (Beck & Juel, 1995; Foorman, Francis, Fletcher, Schnatschneider, & Metha, 1998; Rothstein, Rothstein, & Lauber, 2007). The study involved ELLs (ages 15-17 years of age; n=140) in a true experimental design to determine if Morphological Instruction is an effective instructional approach towards accelerating the acquisition of spelling, vocabulary, and reading comprehension for high school ELLs who face linguistic disadvantages and thereby close the gap between high school English dominant speakers and second language learners. Bivariate and multivariate analyses revealed that each of the "t"-tests and ANCOVAs were found to be of statistical significance in reading, vocabulary, and spelling. The data was significant alone, which made it abundantly clear that each group--control and treatment--regardless of their covariates were judged based on their performance as a class, or cohort, and on the instruction they received, for reading, vocabulary, and spelling vis-a-vis traditional instruction or Morphological Instruction. Thus, Morphological Instruction suggests that it did have a significant effect on whether or not ELL students improved in reading, vocabulary, and spelling to the exclusion of the null and to the acceptance of the alternative hypothesis and research questions indicating, without equivocation, that it can serve as an instructional tool in accelerating the closing of the word gap between ELLs and English dominant high school students. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

Published
2010

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