Simplified Version Research Articles

Smart Agri Bot for Multi-Crop Harvesting

The integration of automation and robots into modern agriculture is crucial for improving output and efficiency. A recent development in this field is the creation of a color-sensing robot specifically designed for agricultural purposes. This robot utilizes advanced color detection technology to accurately identify objects and exert control over them based on their color characteristics. The primary goal of this research is to find solutions for labor-intensive agricultural tasks, particularly fruit and vegetable harvesting. By combining robotics and computer vision technology, this robot aims to streamline these processes. Automation plays a significant role in reducing human effort in routine and frequently performed tasks. In the case of agriculture, color-sensing robots have been employed to pluck fruits and vegetables. The robot's mobile application is controlled through a Bluetooth Module, sending instructions to the microcontroller, and then to the motor. The robot's architecture is also programmed with Arduino, an open-source programming language that is a simplified version of other languages. These robots have the potential to reduce damage, increase productivity, and prove cost- effective, while also freeing up labor resources. In addition to object recognition, the robot's navigational capabilities have been enhanced with the integration of an ultrasonic sensor. This sensor emits high-frequency sound waves and analyzes the echoes to accurately estimate distances to nearby objects. This information is crucial for the robot to identify obstacles in its path, ensuring safe and effective navigation

Polydispersity effect on dry and immersed granular collapses: an experimental study

The column collapse experiment is a simplified version of natural and industrial granular flows. In this set-up, a column built with grains collapses and spreads over a horizontal plane. Granular flows are often studied with a monodisperse distribution; however, this is not the case in natural granular flows where a variety of grain sizes, known as polydispersity, is a common feature. In this work, we study the effect of polydispersity, and of the inherent changes that polydispersity causes in the initial packing fraction, in dry and immersed columns. We show that dry columns are not significantly affected by polydispersity, reaching similar distances at similar times. In contrast, immersed columns are strongly affected by the polydispersity and packing fraction, and the collapse sequence is linked to changes of the basal pore fluid pressure $P$ . At the collapse initiation, negative changes of $P$ beneath the column produce a temporary increase of the column strength. The negative change of $P$ lasts longer in polydisperse columns than in monodisperse columns, delaying the collapse sequence. Conversely, during the column spreading, positive changes of $P$ lead to a decrease of the shear strength. For polydisperse collapses, the excess of $P$ lasts longer, allowing the material to reach farther distances, compared with the collapses of monodisperse materials. Finally, we show that a mobility model that scales the final runout with the collapse kinetic energy remains true for different polydispersity levels in a three-dimensional configuration, capturing the scaling between the micro to macro controlling features.

Analysis of Structure and Function of Ladybird Leg and Subsequent Design and Fabrication of a Simplified Leg Structure for Robotic Applications.

Many insects are able to walk vertically or upside down on both hard and soft surfaces. In beetles such as the ladybird (Coccinella septempunctata), intermolecular forces between tarsal setae on the footpads of the insects make this movement possible. In prior work, adhesion structures made from polydimethylsiloxane (PDMS) that mimic the action of the tarsal setae have been developed. It is proposed that these adhesion structures could be attached to a simplified version of the leg of a ladybird and used in practical applications. For example, the leg structures could potentially be employed in small surveillance drones to enable attachment to surfaces during flights, in order to preserve battery power. Alternatively, the structures could be used in small robotic devices to enable walking on steeply inclined surfaces. In this program of work, the morphology and movement of the leg of a ladybird were closely studied using a 3D X-ray microscope and a high-speed microscope. The positions of the tendons that facilitated movement were identified. From this knowledge, a simplified leg structure using pin-joints was designed and then fabricated using 3-D printing. The PDMS adhesion structures were then attached to the leg structure. The tendons in the actual insect leg were replicated using thread. Typical detachment forces of about 4 N indicated that the simplified leg structure was, in principle, more than capable of supporting the weight of a small device and then detach successfully. Attachment/detachment movement operations were performed using a linear actuator and controlled remotely. Therefore, proof of concept has been demonstrated for the use of such a simplified ladybird leg structure for the attachment/detachment of small robotic devices to horizontal, inclined, or vertical surfaces.

Ductile rupture under cyclic loadings at high triaxiality: The influence of strain hardening and elasticity

Previous works (Devaux et al., 1997; Cheng et al., 2017) have emphasized the effects of strain hardening and elasticity upon ductile rupture of metals under cyclic loading conditions. This work pursues the study and modelling of these two effects by distinct theoretical methods, each coupled with micromechanical finite element simulations of the behaviour of some “representative cell”. For the effect of strain hardening, we employ Morin et al. (2017)’s approach, based on the theory of sequential limit-analysis (Yang, 1993; Leu, 2007; Leblond et al., 2018). This approach is applied to various types of hardening of the metallic matrix: isotropic, linear kinematic, nonlinear kinematic with one or two kinematic variables (Armstrong and Frederick, 2007) , and even a simplified version of Chaboche (1991)’s model accounting for complex cyclic effects. Numerical micromechanical simulations of a hollow sphere made of elastic–plastic materials obeying the various hardening laws considered, and subjected to cyclic loadings at high triaxiality, fully confirm the predictions of the model developed, provided elasticity is made negligible by using an artificially high value of Young’s modulus. When a realistic value is employed, however, the agreement between theoretical predictions and numerical results is degraded, thus emphasizing again the importance of the effect of elasticity in cyclic ductile rupture. To deal with this effect we derive, apparently for the first time, an evolution equation of the porosity accounting for (compressible) elasticity. However, numerical micromechanical simulations reveal that simply using this new evolution law, while keeping all other aspects of the model unchanged, remains insufficient to get a good match of theoretical and numerical results. Such a match is achieved by introducing the ad hoc hypothesis that the yield criterion and flow rule derived from sequential analysis still apply in the presence of elasticity, but with some “effective porosity” slightly differing from the true one through some heuristic, adjustable factor.

The positive effect of blue luminescent pathways on urban park visitor’s affective states: A virtual reality online study measuring facial expressions and self-reports

The colour blue often elicits feelings of calmness and contentment, for which evidence has largely been provided in daytime settings. It is unclear whether pathways illuminated in blue, for example, in urban recreational park areas at night confers the same positive impact on night time park visitors. To tackle this open empirical question, we investigated how adding blue self-luminous pavement to park lighting at night time affects park visitors’ emotions compared to conventional white street light illumination. Our goal is to inform design decisions aimed at enhancing the emotional well-being of people outdoors at night in urban environments. Participants’ emotional response was captured at four different time points while watching a video of a walk in a virtual urban park at night, which was lit with white street lights only or with the addition of blue luminescent pavement on the walked paths (between-subject design). To capture visitor’s emotions, we used a simplified version of the Geneva Emotion Wheel (GEW) instrument and online facial expression recognition technology as subjective (self-reports) and objective (physiological) measures of emotion, respectively. The results of the GEW self-reports showed that the addition of a blue self-luminous pavement in a park during night time yielded more positive affect than standard white lighting in park visitors for the first half of the walk. In the second half of the walk through the park, participants’ affective states seemed to equalize between the two lighting conditions. In contrast, sensory data on facial expressions indicated no difference between participants’ emotional states over the whole walk in the two experimental conditions. Consistent with the positive emotional state perceived in the second half of the walk, the state of relaxation experienced after the walk also did not differ between the two lighting conditions. Furthermore, participants’ relaxation judgements after the park walk were more negative overall for females than the more neutral ratings of males. Our results highlight the importance of lighting colour at night for the design of future affect-smart cities that may consider individual and group characteristics with the ultimate intent of promoting public well-being.

Analysis of planar arbitrarily curved microbeams with simplified strain gradient theory and Timoshenko–Ehrenfest beam model

As the first endeavor in the context of Mindlin’s strain gradient theory, this study contributes a systematic and rigorous derivation for governing equations and boundary conditions of planar arbitrarily curved microbeams. The Timoshenko–Ehrenfest beam model is incorporated into a simplified version of Mindlin’s strain gradient theory. Kinematic unknowns include displacement components of the beam axis in the local coordinate system and the rotation of cross-section. Since the derived governing equations and boundary conditions are extremely complex, analytical solutions are not achievable for microbeams having non-uniform curvature. To facilitate the numerical analysis, two isogeometric collocation formulations are proposed, that is, displacement-based and mixed formulations. Several tests are designed to evaluate the accuracy and reliability of the proposed isogeometric collocation formulations, especially with respect to the well-known locking pathology. It is found that the mixed formulation is more accurate and robust than the displacement-based one. Therefore, the mixed formulation is then used to numerically investigate the size-dependent behavior and stiffening effect. Furthermore, some informative tests are performed to delineate the significance of the curviness in the prediction of structural responses of planar arbitrarily curved microbeams, which appears to be still an unanswered issue.

Evaluation of the environmental quality monitoring protocol for Amazonian streams: a systematic review

The Amazon Rainforest is renowned for its extraordinary biodiversity and the ravages of pervasive deforestation. The removal of natural vegetation significantly affects Amazonian streams, leading to alterations in their environmental conditions. In the United States, the Environmental Protection Agency has devised a comprehensive protocol to monitor changes in the environmental quality of streams. Since 2011, the Sustainable Amazon Network has implemented this protocol in Amazonian streams. Our systematic review aimed to address the following questions: i) How widely has the protocol been employed in Amazonian streams?; ii) Is the utilization of this protocol well-distributed across the Amazon Basin?; iii) Which types of land use have been assessed using this protocol?; iv) Which components of the aquatic biota have been studied in conjunction with the protocol?; and, v) Which metrics of the protocol are most crucial for elucidating aquatic biota distribution? We conducted searches using the Web of Science and Google Scholar databases, identifying 34 studies that directly aligned with our objectives. It was observed that the Eastern Amazon had the highest number of streams evaluated. Additionally, aquatic insects emerged as an effective tool when utilized alongside the protocol for evaluating the impacts of changes in land use. Ultimately, the most important metrics for assessing impacts on aquatic biota were shelter availability in the channels, the preservation status of riparian forests, and water quality. We recommend developing a simplified version of this protocol to facilitate its application for research teams with limited personnel and financial resources available for fieldwork. Keywords: aquatic conservation, biomonitoring, land use change, sampling efficiency, stream ecology.

A proven optimal result for a benchmark instance of the uncapacitated examination timetabling problem

AbstractExamination timetabling is a problem well known to the scheduling community. Its simplest version, which is the uncapacitated examination timetabling problem, is easily described and comprehended. Nevertheless, proof of optimality is notoriously difficult even for moderate size problems. In this paper, we describe the effort that our team exercised in finally proving the optimality of the sta83 instance of Carter’s dataset. The problem was decomposed naturally in three parts and for each part a different approach managed to prove optimality of the currently best known solution. This work also presents optimal solutions to subproblems that exist in various public datasets problems and two best known solutions of such problems.

Home Treatment for Active Cancer Patients With Low-Risk Pulmonary Embolism - A Predetermined Companion Report From the ONCO PE Trial.

Patients with appropriately selected low-risk pulmonary embolism (PE) can be treated at home, although it has been controversial whether applies to patients with cancer, who are considered not to be at low risk.Methods and Results: The current predetermined companion report from the ONCO PE trial evaluated the 3-month clinical outcomes of patients with home treatment and those with in-hospital treatment. The ONCO PE trial was a multicenter, randomized clinical trial among 32 institutions in Japan investigating the optimal duration of rivaroxaban treatment in cancer-associated PE patients with a score of 1 using the simplified version of the Pulmonary Embolism Severity Index (sPESI). Among 178 study patients, there were 66 (37%) in the home treatment group and 112 (63%) in the in-hospital treatment group. The primary endpoint of a composite of PE-related death, recurrent venous thromboembolism (VTE) and major bleeding occurred in 3 patients (4.6% [0.0-9.6%]) in the home treatment group and in 2 patients (1.8% [0.0-4.3%]) in the in-hospital treatment group. In the home treatment group, there were no cases of PE-related death or recurrent VTE, but major bleeding occurred in 3 patients (4.6% [0.0-9.6%]), and 2 patients (3.0% [0.0-7.2%]) required hospitalization due to bleeding events. Active cancer patients with PE of sPESI score=1 could be potential candidates for home treatment.

A simplified version of rapid susceptibility testing of bacteria and yeasts using optical nanomotion detection.

We present a novel optical nanomotion-based rapid antibiotic and antifungal susceptibility test. The technique consisted of studying the effects of antibiotics or antifungals on the nanometric scale displacements of bacteria or yeasts to assess their sensitivity or resistance to drugs. The technique relies on a traditional optical microscope, a video camera, and custom-made image analysis software. It provides reliable results in a time frame of 2-4 h and can be applied to motile, non-motile, fast, and slowly growing microorganisms. Due to its extreme simplicity and low cost, the technique can be easily implemented in laboratories and medical centers in developing countries.

Embracing Uncertainty: Utilizing the Narrated Past to Move toward a Polyvocal Inclusive History

The reality of the past is complex in its many facets and perspectives; however, dominant historical narratives have overtaken the representation of the past through a simplified version from a single perspective. Academics are complicit in this process, not only by emphasizing some types of (historic) source material over others but also by claiming authority over the past. Sharing the authority to narrate the past is therefore a crucial step to allow uncertainty back into the historical narrative. This article briefly discusses how this “objectified past” and the narrated past can coexist alongside each other when we construct history as a polyvocal plural narrative that is aware of its contemporary agenda and public. To exemplify how these mechanisms work in both a European and an Asian context, I will discuss case studies related to my research on the Banda Islands in Indonesia as well as my recent work in the postindustrial city Esch-sur-Alzette in Luxembourg.

A methodology to reduce the computational effort in 3D-CFD simulations of plate-fin heat exchangers

The analysis of a plate-fin heat exchanger performance requires the evaluation of key parameters such as heat transfer and pressure drop. In this regard, Computational Fluid Dynamics (CFD) can be proficiently adopted, at the design stage, to predict the performance of plate-fin heat exchangers. However, these last are often characterized by a complex geometry, such as in the case of plate exchangers with turbulators, leading to a huge computational effort, which often exceeds the available resources. In this study, a numerical methodology for the simulation of plate heat exchangers is proposed, to bypass the limits imposed by the computational cost. The methodology relies on the simulation of a minimal portion of the exchanger (two plates, one per fluid) characterized by periodic boundary conditions (that mimic the presence of several layers). The total heat exchanged is obtained simply multiplying the calculated heat transfer by the number of plate couples composing the device. Moreover, the two plates allow to calibrate porous media which are adopted to rebuild (in a simplified version) the two fluid circuits of the whole exchanger and obtain the overall pressure drop across the device for both the hot and cold fluids.The proposed approach is validated against experimental data of an oil cooler for automotive application, that is a plate-fin heat exchanger characterized by the presence of turbulators. The numerical outcomes are compared to the experiments in terms of pressure drop and heat transfer for a wide range of volumetric flow rates. Particular attention is devoted to the mesh sensitivity and the adopted computational grid minimizes the number of cells (and, thus, the computational cost), without compromising the accuracy. Moreover, the Reynolds-Stress-Transport turbulence model is accurately selected among the most diffused ones, in order to properly match the test bench data.The proposed methodology allows to reduce of nearly one order of magnitude the total number of cells required for the simulation of the heat exchanger performance. The heat transfer is predicted with high accuracy, i.e. error is always lower than 4%. As for the pressure loss, the deviation compared to the experiments increases up to nearly 15% (for one of the simulated conditions) but it is considered still acceptable.

Exploring the nonclassical dynamics of the “classical” Schrödinger equation

The introduction of nonlinearities into the Schrödinger equation has been considered in the literature as an effective manner to describe the action of external environments or mean fields. Here, we explore the nonlinear effects induced by subtracting a term proportional to Bohm’s quantum potential to the usual (linear) Schrödinger equation, which generates the so-called “classical” Schrödinger equation. Although a simple nonlinear transformation allows us to recover the well-known classical Hamilton–Jacobi equation, by combining a series of analytical results (in the limiting cases) and simulations (whenever the analytical treatment is unaffordable), we find an analytical explanation to why the dynamics in the nonlinear “classical” regime is still strongly nonclassical. This is even more evident by establishing a one-to-one comparison between the Bohmian trajectories associated with the corresponding wave function and the classical trajectories that one should obtain. Based on these observations, it is clear that the transition to a fully classical regime requires extra conditions in order to remove any trace of coherence, which is the truly distinctive trait of quantum mechanics. This behavior is investigated in three paradigmatic cases, namely, the dispersion of a free propagating localized particle, the harmonic oscillator, and a simplified version of Young’s two-slit experiment.

34 A survey of the Oklahoma State University Cowculator user preferences

Abstract The Oklahoma State University Cowculator is a free, easy to use model designed to assist cattle producers in making informed decisions regarding the nutrition of their herd. The Cowculator operates as a spreadsheet-based model, which collects information from the 2016 National Academy of Science, Engineering, and Medicine’s Nutrient Requirements for Beef Cattle, previous editions of the book, and previous research data. Producers have the option to adjust animal characteristics, feed and forage values, and diet composition to fit certain production objectives. In 2022, a Qualtrics survey was developed to determine perception of users of the program and their likes and dislikes. When users download the program, they are required to enter their name, email address, and zip code. A link to the survey was emailed to each address registered within the Cowculator database, with an email reminder sent out 30 days later. The survey yielded 233 responses. According to user download data, in 2022 the Cowculator was downloaded 2,090 times from 41 states and 53 countries. Based on email addresses ending in “.edu” the program was downloaded by faculty or students from 135 different universities, colleges, or other technical institutions. Of the respondents, 60% identified as beef cattle producers, 16% as industry professionals (e.g., consultants, veterinarians), 11% as extension personnel, 7% as research or teaching faculty, and 6% as students. Regarding the type of enterprise which the program was used for, 52% responded with cow/calf, 33% growing or stocker cattle, and 15% finishing cattle. The survey indicated that 88% of respondents were able to utilize the program effectively to evaluate or modify their nutrition program, while 16% indicated they were not successful in using the program. The survey asked respondents to give their opinion on the accuracy of the program. 69% indicated that it yielded “mostly accurate” projections, 23% responded with “very accurate”, and 5% perceived the program to be inaccurate or marginally accurate. Users of the program estimated the average annual benefit of the program to be $1,500. The respondents were asked to select what they liked about the program and what they felt needed improvement. It was indicated that the most liked features were that the program was free and that it was easy to use. The features that were indicated as needing improvement where the limited pre-added list of feedstuffs and the lack of availability of a simplified app version of the program. The results of this survey provide valuable insights regarding user demographics, as well as what can further be adjusted within the Cowculator to best fit the needs of the users.

Validation of a screening panel for pediatric metabolic dysfunction-associated steatotic liver disease using metabolomics.

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as NAFLD, is the most common liver disease in children. Liver biopsy remains the gold standard for diagnosis, although more efficient screening methods are needed. We previously developed a novel NAFLD screening panel in youth using machine learning applied to high-resolution metabolomics and clinical phenotype data. Our objective was to validate this panel in a separate cohort, which consisted of a combined cross-sectional sample of 161 children with stored frozen samples (75% male, 12.8±2.6 years of age, body mass index 31.0±7.0kg/m2, 81% with MASLD, 58% Hispanic race/ethnicity). Clinical data were collected from all children, and high-resolution metabolomics was performed using their fasting serum samples. MASLD was assessed by MRI-proton density fat fraction or liver biopsy and cardiometabolic factors. Our previously developed panel included waist circumference, triglycerides, whole-body insulin sensitivity index, 3 amino acids, 2 phospholipids, dihydrothymine, and 2 unknowns. To improve feasibility, a simplified version without the unknowns was utilized in the present study. Since the panel was modified, the data were split into training (67%) and test (33%) sets to assess the validity of the panel. Our present highest-performing modified model, with 4 clinical variables and 8 metabolomics features, achieved an AUROC of 0.92, 95% sensitivity, and 80% specificity for detecting MASLD in the test set. Therefore, this panel has promising potential for use as a screening tool for MASLD in youth.

WALIS dashboard: An online tool to explore a global paleo sea-level database.

In this paper, we present WALIS Dashboard, an open-access interface to the World Atlas of Last Interglacial Shorelines (WALIS), which was developed and compiled thanks to funding from the European Research Council. WALIS is a database that includes thousands of samples (dated with different radiometric methods) and sea-level indicators formed during the Last Interglacial (~80 to 130 ka). The WALIS Dashboard was coded in R (shiny app), and allows querying a simplified version of WALIS by either geographic extent or by attributes. The user can then download the queried data and perform simple and reproducible data analysis. The WALIS Dashboard can be used both online and offline.

GU-Net: Diffuse Glioma Segmentation in Brain MRIs Using a Modified U-Net under Data Constraints

Diffuse gliomas are a prevalent type of brain tumor in adults. Currently, treating these tumors is a time-consuming process. Radiologists manually identify and segment diffuse gliomas in Magnetic Resonance Images (MRIs), which are then used as reference by surgeons during treatment. Prior research conducted on automating this process utilizes machine learning (ML) models such as CNNs and U-Nets. One key piece of prior work is BU-Net, which slightly alters the architecture of U-Net. To contribute to this field, we propose a novel, simplified version of BU-Net, dubbed GU-Net, optimized specifically for low-computation neuroimaging. The proposed model is trained on a subset of the BraTS 2021 dataset, consisting of a mere 1647 images stemming from 549 different brain MRIs. Under data constraints, we achieve a 71.58% dice similarity coefficient (DSC) and 64.29% Intersection Over Union (IOU) on the testing dataset. Compared with U-Net's 0.672 and 0.611 and BU-Net's 0.613 and 0.554 on the same dataset, GU-Net’s success under data constraints compared to the other two models is shown. Our work specifically advances diagnosis in underprivileged areas and hospitals with less funding, as GU-Net requires less data to be used and has higher efficiency compared to existing solutions.

Inventory Management with Advance Booking Information: The Case of Surgical Supplies and Elective Surgeries

Problem definition: Medical operations require a large volume and variety of consumable supplies that are kept in hospital inventory and replenished on a regular basis. Stringent requirements on the availability of these supplies, together with high variability in their daily usage, contribute to the high inventory costs of the surgical departments in hospitals. We investigate the value of utilizing Advance Booking Information (ABI) on elective surgeries—which are often booked up to months in advance—in reducing inventory costs. Methodology/results: We study a single-item, periodic-review, stochastic inventory control problem, where the item demand in each period is driven by the number and type of surgeries requiring the item, and with the available information on elective surgeries integrated into the ordering decisions. Given that item usage from each case is uncertain and only realized after the surgery, ABI provides imperfect information on future demand. Through exact analysis of a simplified version of the problem, as well as extensive numerical experiments using synthetic and real data, enabled using a state aggregation technique, we provide insights on and quantify the value of using ABI as a function of the number of periods of ABI integrated into the ordering decisions. We identify a relevant parameter regime—namely, high backlog (relative to holding) costs and when surgeries are booked sufficiently in advance—where the value of using ABI could be significant and the majority of the benefits can be gained through incorporating only one period of ABI beyond the order lead time. In a case study conducted using real data, we observe up to 26% reduction in average inventory levels, without violating the service levels. Managerial implications: By incorporating readily available elective surgery schedules into replenishment decisions of surgical supplies, hospitals could significantly reduce inventory costs without compromising the availability of the supplies. Funding: This work was partially funded by The Ontario Ministry of Government and Consumer Services (MGCS). The views expressed in the paper are the views of the authors and do not necessarily reflect those of the Province. Supplemental Material: The e-companion is available at https://doi.org/10.1287/msom.2021.0063 .

DOMESTIC ORIGINAL SIN OF SOVEREIGN DEBT IN TÜRKİYE

The study analyzes the original sin of sovereign debt in Türkiye with a focus on domestic original sin. Eichengreen and Hausmann (1999) define original sin as the inability of a country to borrow in its own currency in the international market, while the issuance of foreign currency debt in the domestic market is defined as domestic original sin (Eichengreen, Hausmann, and Panizza, 2003). In this context, the structure of the debt portfolio was evaluated based on the indicators developed by Eichengreen, et al. (2003) and its simplified version widely used in the literature. Based on the analysis of the sovereign debt portfolio, it has been concluded that although the debt stock to GDP ratio is relatively low in Türkiye, the domestic original sin has reached historically high levels and currency mismatch is significant.

A Modified Slicing Method with Multi-Dimensional Unfolding to Measure Hadron-Argon Cross Sections

Liquid argon technology is widely used by many previous and current neutrino experiments, and it is also promising for future large-scale neutrino experiments. When detecting neutrinos using liquid argon, many hadrons are involved, which can also interact with argon nuclei. In order to gain a better understanding of the detection processes, and to simulate neutrino events, knowledge of hadron-argon cross sections is needed. This paper describes a new procedure which improves upon the previous work with multi-dimensional unfolding to measure hadron-argon cross sections in a liquid argon time projection chamber. Through a simplified version of simulation, we demonstrate the validity of this procedure.