1,921 research outputs found
Indefensibility, Skepticism and Conceptual Truth
It is true of many truths that I do not believe them. It is\ud
equally true that I cannot rationally assert of any such truth\ud
that it is true and that I do not believe it. Such a claim is\ud
indefensible, i.e. for internal reasons unable to convince. I\ud
claim that such is the skeptic's predicament, trying to\ud
convince us to bracket knowledge claims we have good\ud
grounds to take ourselves to be entitled to. An analysis of\ud
skepticism as an epidemic rather than epistemic challenge\ud
will shed new light on what it is to doubt a proposition and\ud
provide us with an analysis of conceptual truths as those\ud
which cannot rationally be doubted
Machine learning regression on hyperspectral data to estimate multiple water parameters
In this paper, we present a regression framework involving several machine
learning models to estimate water parameters based on hyperspectral data.
Measurements from a multi-sensor field campaign, conducted on the River Elbe,
Germany, represent the benchmark dataset. It contains hyperspectral data and
the five water parameters chlorophyll a, green algae, diatoms, CDOM and
turbidity. We apply a PCA for the high-dimensional data as a possible
preprocessing step. Then, we evaluate the performance of the regression
framework with and without this preprocessing step. The regression results of
the framework clearly reveal the potential of estimating water parameters based
on hyperspectral data with machine learning. The proposed framework provides
the basis for further investigations, such as adapting the framework to
estimate water parameters of different inland waters.Comment: This work has been accepted to the IEEE WHISPERS 2018 conference. (C)
2018 IEE
Overcommitment in Cloud Services -- Bin packing with Chance Constraints
This paper considers a traditional problem of resource allocation, scheduling
jobs on machines. One such recent application is cloud computing, where jobs
arrive in an online fashion with capacity requirements and need to be
immediately scheduled on physical machines in data centers. It is often
observed that the requested capacities are not fully utilized, hence offering
an opportunity to employ an overcommitment policy, i.e., selling resources
beyond capacity. Setting the right overcommitment level can induce a
significant cost reduction for the cloud provider, while only inducing a very
low risk of violating capacity constraints. We introduce and study a model that
quantifies the value of overcommitment by modeling the problem as a bin packing
with chance constraints. We then propose an alternative formulation that
transforms each chance constraint into a submodular function. We show that our
model captures the risk pooling effect and can guide scheduling and
overcommitment decisions. We also develop a family of online algorithms that
are intuitive, easy to implement and provide a constant factor guarantee from
optimal. Finally, we calibrate our model using realistic workload data, and
test our approach in a practical setting. Our analysis and experiments
illustrate the benefit of overcommitment in cloud services, and suggest a cost
reduction of 1.5% to 17% depending on the provider's risk tolerance
Estimating Chlorophyll a Concentrations of Several Inland Waters with Hyperspectral Data and Machine Learning Models
Water is a key component of life, the natural environment and human health.
For monitoring the conditions of a water body, the chlorophyll a concentration
can serve as a proxy for nutrients and oxygen supply. In situ measurements of
water quality parameters are often time-consuming, expensive and limited in
areal validity. Therefore, we apply remote sensing techniques. During field
campaigns, we collected hyperspectral data with a spectrometer and in situ
measured chlorophyll a concentrations of 13 inland water bodies with different
spectral characteristics. One objective of this study is to estimate
chlorophyll a concentrations of these inland waters by applying three machine
learning regression models: Random Forest, Support Vector Machine and an
Artificial Neural Network. Additionally, we simulate four different
hyperspectral resolutions of the spectrometer data to investigate the effects
on the estimation performance. Furthermore, the application of first order
derivatives of the spectra is evaluated in turn to the regression performance.
This study reveals the potential of combining machine learning approaches and
remote sensing data for inland waters. Each machine learning model achieves an
R2-score between 80 % to 90 % for the regression on chlorophyll a
concentrations. The random forest model benefits clearly from the applied
derivatives of the spectra. In further studies, we will focus on the
application of machine learning models on spectral satellite data to enhance
the area-wide estimation of chlorophyll a concentration for inland waters.Comment: Accepted at ISPRS Geospatial Week 2019 in Ensched
Fallstudie Vontobel : «Digitalisiertes Service Management schafft Kundennutzen»
Die Fallstudie aus den Operation Services des Schweizer Private Wealth und Asset Managers Vontobel zeigt, dass auch die digitale Transformation interner Bereitstellungsprozesse ein hohes Nutzenpotenzial birgt und dazu beiträgt, dass sich Servicefunktionen in der Organisation neu positionieren und ihre Rolle in der Organisation verändern können. Kundenzufriedenheit, mehr Transparenz und Effizienz in der Leistungserbringung und eine bessere Verfügbarkeit von Informationen in kritischen Supportprozessen standen im Mittelpunkt der in dieser Fallstudie beschriebenen Transformation des IT-gestützten Service Managements bei Vontobel
Pathways to Developing Digital Capabilities within Entrepreneurial Initiatives in Pre-Digital Organizations
To enable new digital business models, pre-digital organizations launch entrepreneurial initiatives. However, in developing the required digital capabilities, pre-digital organizations often face challenges as they are marked by the ways they have historically established their organizational identity. Research on how pre-digital organizations can develop digital capabilities remains scarce. This study draws on a single case study to illustrate potential pathways for the development of digital capabilities. Two key characteristics are identified: the source of digital capability development and the set-up of the actors involved. The authors synthesize four possible pathway manifestations, discuss the dynamic nature of pathway combinations, and suggest that managing a portfolio of pathways may be crucial for pre-digital organizations. Therefore, the study contributes to a better understanding of digital transformation in pre-digital organizations. Furthermore, it provides guidance for practitioners to reflect on when deciding which pathways to follow
ir_metadata: An Extensible Metadata Schema for IR Experiments
The information retrieval (IR) community has a strong tradition of making the
computational artifacts and resources available for future reuse, allowing the
validation of experimental results. Besides the actual test collections, the
underlying run files are often hosted in data archives as part of conferences
like TREC, CLEF, or NTCIR. Unfortunately, the run data itself does not provide
much information about the underlying experiment. For instance, the single run
file is not of much use without the context of the shared task's website or the
run data archive. In other domains, like the social sciences, it is good
practice to annotate research data with metadata. In this work, we introduce
ir_metadata - an extensible metadata schema for TREC run files based on the
PRIMAD model. We propose to align the metadata annotations to PRIMAD, which
considers components of computational experiments that can affect
reproducibility. Furthermore, we outline important components and information
that should be reported in the metadata and give evidence from the literature.
To demonstrate the usefulness of these metadata annotations, we implement new
features in repro_eval that support the outlined metadata schema for the use
case of reproducibility studies. Additionally, we curate a dataset with run
files derived from experiments with different instantiations of PRIMAD
components and annotate these with the corresponding metadata. In the
experiments, we cover reproducibility experiments that are identified by the
metadata and classified by PRIMAD. With this work, we enable IR researchers to
annotate TREC run files and improve the reuse value of experimental artifacts
even further.Comment: Resource pape
Evaluating Temporal Persistence Using Replicability Measures
In real-world Information Retrieval (IR) experiments, the Evaluation
Environment (EE) is exposed to constant change. Documents are added, removed,
or updated, and the information need and the search behavior of users is
evolving. Simultaneously, IR systems are expected to retain a consistent
quality. The LongEval Lab seeks to investigate the longitudinal persistence of
IR systems, and in this work, we describe our participation. We submitted runs
of five advanced retrieval systems, namely a Reciprocal Rank Fusion (RRF)
approach, ColBERT, monoT5, Doc2Query, and E5, to both sub-tasks. Further, we
cast the longitudinal evaluation as a replicability study to better understand
the temporal change observed. As a result, we quantify the persistence of the
submitted runs and see great potential in this evaluation method.Comment: To be published in Proceedings of the Working Notes of CLEF 2023 -
Conference and Labs of the Evaluation Forum, Thessaloniki, Greece 18 - 21,
202
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