Complexity Transfer Research Articles

The Ancient Greek Potter’s Wheel: Experimental Archaeology and Web Applications for Velocity Analysis

The potter’s wheel is central to the understanding of ancient technology, knowledge transfer, and social complexity. With scant evidence of potter’s wheels from antiquity, experimental projects with replica potter’s wheels can help researchers address larger questions on ceramic production. One such set of experiments, performed using the Ancient Greek wheel replica in Tucson modelled on Athenian and Corinthian iconographic evidence, provided useful insight into the qualitative experience of ancient potters. In past experiments, the quantitative analysis of the throwing sessions included data on wheel velocity which had been collected collected over large intervals, comprising entire stages of the throwing process. While this method provides an overview of rotational speed, a continuous velocity graph provides a clearer picture collected data on wheel velocity. To address this, we developed a web application (WheelVis; brandonneth.github.io/wheelvis) to aid in the velocity analysis of experimental potter’s wheels. Users provide a recording of the throwing session and while advancing through the recording, they mark points where the wheel has completed rotations. Using the time intervals between these points, the tool reconstructs a graph of the velocity of the wheel throughout the throwing session. This innovative application provides fast, fine-grained velocity information, and helps archaeologists answer questions about the physical properties of their experimental replicas or wheels used in traditional workshops. Future development of the application will include contextual partitions to allow users to split the throw into different stages, enabling further analysis into the throwing process. Moreover, intelligent error detection would notify users when a mark is likely to be made in error and allow them to correct their mistake.

Complexity transfer in supplier-customer systems

This paper uses a multiple case-study methodology to investigate complexity transfer (CT) in manufacturing supplier-customer systems, leading to a new model of complexity transfer. An entropic-related complexity measure is applied to three supplier-customer systems, internally within each organisation and at their supplier-customer interface. The results are compared and integrated to provide cross-case analyses and insights. Although CT has been acknowledged in the literature to occur towards upstream supply chain (SC) partners, e.g. in the context of the bullwhip effect, this paper provides evidence that CT may also occur towards downstream SC partners. This study also highlights that complexity can be managed through significant and sustained operational interventions. Our new empirically-tested model of CT identifies four organisational types: Sink, Source, Equilibrium, and Boom or Bust, according to their transfer of internally-generated and externally-accepted complexity. This new model enables an in-depth representation of the transfer of complexity and of its impact on SC partnerships. Managers may use this CT model to develop complexity management insights and to identify structural and operational changes – at organisational level, and systemic SC changes that may reduce the costs associated with complexity.

Analysis of Interhospital Transfer of Critically Ill Patients to the Coronary Care Unit of a Highly Complex Hospital

Background: Interhospital transfer of critically ill patients is frequent in our country. However, despite the existence of emergency medical transfer services both in public and private settings, no scientific publications have been generated regarding the transfer of critically ill patients to understand their operation, planning and results. Objective: The aim of this study was to describe the conditions of interhospital transfer of cardiovascular disease patients. Methods: This was an observational, prospective, multicenter design study, analyzing interhospital land transfer of patients admitted to a third level coronary care unit between April 2014 and April 2015. The transfer physician was surveyed. Complications related to hospital transfer and mortality were also recorded. Results: A total of 214 transfers were analyzed. Median transfer time was 30 minutes (IQR 18.5-50). Among all transfers, 16.1% of cases were considered to be at high risk, 71.2% at moderate risk and 12.7% at low risk, according to a validated score. The main diagnoses were acute coronary syndrome (66.8%), heart failure (8.9%) and bradyarrhythmia or blockade (3.7%). In 73.5% of highrisk transfers, high complexity ambulances were used, and in low- and moderate-risk transfers (30.8% and 28.9%, respectively), they were carried out with low complexity ambulances. Fifty percent of transfers were performed by resident physicians; 10.8% of cases presented with some complication during the transfer and/or during the first hour. Complications were more frequent in high-risk transfers and were associated with in-hospital mortality. There was no association between estimated increased risk of transfer and greater ambulance complexity (p=0.6). Conclusion: Transfer scheduling was not adequate. The calculated risk of transfers was predominantly low, with a high proportion of severe complications, which impacted in in-hospital mortality.

A spatial compression technique for head-related transfer function interpolation and complexity estimation.

A head-related transfer function (HRTF) model employing Legendre polynomials (LPs) is evaluated as an HRTF spatial complexity indicator and interpolation technique in the azimuth plane. LPs are a set of orthogonal functions derived on the sphere which can be used to compress an HRTF dataset by transforming it into a lower dimensional space. The LP compression technique was applied to various HRTF datasets, both real and synthetic, to determine how much different HRTFs can be compressed with respect to their structural complexity and their spatial resolution. The spatial complexity of different datasets was evaluated quantitatively by defining an HRTF spatial complexity index, which considers the rate of change in HRTF power spectrum with respect to spatial position. The results indicate that the compression realized by the LP technique is largely independent of the number of spatial samples in the HRTF dataset, while compressibility tracks the HRTF spatial complexity index so that more LP coefficients are needed to represent an HRTF dataset with a larger complexity index. The slope of the complexity index with respect to sub-sampling density can be used as a predictor for high interpolation error.

Robust Two-Phase RZ Asynchronous SoC Interconnects

A novel two-phase RZ delay-insensitive asynchronous handshaking protocol for on-chip communication has been developed along with an efficient and robust dual-rail circuit implementation (Transmitter/Receiver). Performance was verified using SPICE simulations with a 0.13 μm, 1.2 V technology and compared to that of the best-in-class asynchronous transceivers in terms of forward and backward latencies, throughput, energy per bit transfer and design complexity. Results demonstrate the superior overall performance of the new transceiver.

L1 Transfer and L2 Complexity as Factors in Syllabus Design

Traditionally, second language syllabus organization has been based on the assumption that how a language is described is related to how it is processed by learners of that language. This article examines two traditional approaches to syllabus design in terms of how each defines this relationship. Underlying one approach is the assumption that second language (L2) structures which differ most from equivalent structures in a learner's native language (L1) are also the most difficult to learn and should therefore be given greatest emphasis in the syllabus. The other approach is based on the premise that there is a direct relationship between linguistic complexity and learning difficulty and that a syllabus should therefore present target structures to the learner in order of increasing linguistic complexity. These approaches are evaluated from linguistic perspectives on the nature of language and psycholinguistic evidence on the sequence of language acquisition. Recent studies on interlanguage development are cited to argue that syllabus design can be enhanced by attention to both approaches-more specifically, to the issues of first language transfer and target language complexity. The article does not advocate a return to exclusive use of either approach; rather, it emphasizes new perspectives which each can bring to the selection and grading of syllabus items.