Comparison of manual snow water equivalent measurements: questioning the reference for the true SWE value

Manual measurement of snow water equivalent (SWE) is still important today for several applications such as hydrological model validation. This measurement can be performed with different types of snow tube sampler or by a snow pit. Although these methods have been performed for several decades, there is an apparent lack of information required to have a consensus regarding the best reference for “true” SWE. We define and estimate the uncertainty and measurement error of different methods of snow pits and snow samplers. Analysis was based upon measurements taken over five consecutive winters (2016–2020) from the same flat and open area. This study compares two snow pit methods and three snow samplers. In addition to including the Standard Federal sampler (SFS), this study documents the first use of two new large diameter samplers, the Hydro-Québec sampler (HQS) and Université Laval sampler (ULS). Large diameter samplers had lowest uncertainty (2.6 to 4.0 %). Snow pit methods had higher uncertainty due to instruments (7.1 to 11.4 %), close to that of the SFS (mean = 10.4 %). Given its larger collected snow volume for estimating SWE and its lower uncertainty, we posit that ULS represents the most appropriate method of reference for “true” SWE. By considering ULS as the reference in calculating mean bias error (MBE), different snow pit methods overestimated SWE by 16.6 to 26.2 %, which was much higher than SFS (8.4 %). This study suggests that large diameter samplers are the best method for estimating “true” SWE.

Uncertainty of the Imported Products and Its Effect on the Income Distribution of Importer

This paper aims to test the uncertainty of the imported products and its effect on the income distribution of importers. This research firstly shows Korea as the risk preference. We show that the relationship between capital and labor has been evolved from when there is no uncertainty to when there is uncertainty, while the relationship between import and capital is complementary. This result proves that the lower uncertainty of imported products hampers the capital of the importing country while it benefits the labor market.

SWAT Model Adaptability to a Small Mountainous Forested Watershed in Central Romania

This study aims to build and test the adaptability and reliability of the Soil and Water Assessment Tool hydrological model in a small mountain forested watershed. This ungauged watershed covers 184 km2 and supplies 90% of blue water for the Brașov metropolitan area, the second largest metropolitan area of Romania. After building a custom database at the forest management compartment level, the SWAT model was run. Further, using the SWAT-CUP software under the SUFI2 algorithm, we identified the most sensitive parameters required in the calibration and validation stage. Moreover, the sensitivity analysis revealed that the surface runoff is mainly influenced by soil, groundwater and vegetation condition parameters. The calibration was carried out for 2001‒2010, while the 1996‒1999 period was used for model validation. Both procedures have indicated satisfactory performance and a lower uncertainty of model results in replicating river discharge compared with observed discharge. This research demonstrates that the SWAT model can be applied in small ungauged watersheds after an appropriate parameterisation of its databases. Furthermore, this tool is appropriate to support decision-makers in conceiving sustainable watershed management. It also guides prioritising the most suitable measures to increase the river basin resilience and ensure the water demand under climate change.

Risk Attitude in Multicriteria Decision Analysis: A Compromise Approach

In fields on which decisions need to be taken including health, as we are seeing nowadays in the COVID-19 crisis, decision-makers face multiple criteria and results with a random component. In stochastic multicriteria decision-making models, the risk attitude of the decision maker is a relevant factor. Traditionally, the shape of a utility function is the only element that represents the decision maker’s risk attitude. The eduction process of multi-attribute utility functions implies some operational drawbacks, and it is not always easy. In this paper, we propose a new element with which the decision maker’s risk attitude can be implemented: the selection of the stochastic efficiency concept to be used during a decision analysis. We suggest representing the risk attitude as a conflict between two poles: risk neutral attitude, associated with best expectations, and risk aversion attitude, associated with a lower uncertainty. The Extended Goal Programming formulation has inspired the parameter that is introduced in a new risk attitude formulation. This parameter reflects the trade-off between the two classical poles with respect to risk attitude. Thus, we have produced a new stochastic efficiency concept that we call Compromise Efficiency.

Measurement of Analog Modulation Index with a Calibrated Radio Frequency Attenuator

This paper presents a method for the accurate and traceable measurement of the analog modulation index. A calibrated step attenuator was used as the main apparatus because it has a higher dynamic range and lower uncertainty than a spectrum analyzer or an oscilloscope. In amplitude modulation (AM), the modulation index is obtained from the amplitude difference between the carrier and the first sideband, as in the conventional method. The resolution and calibration uncertainties of the step attenuator were propagated to the measurement uncertainty of the modulation index. The uncertainty produced by the impedance mismatch and repeatability was also included. For frequency modulation (FM) and phase modulation (PM), the modulation index, β, was estimated (with the step attenuator) from the spectrum of each sideband through the nonlinear fitting of the Bessel function. Thus, the uncertainty of the fitting process was added to the uncertainty of the measurement. The three modulations, AM, FM, and PM, exhibited an expanded uncertainty (approximately 95% confidence level, k = 2) of 0.372% for 50% nominal depth of the AM, 88.8 Hz for the peak frequency deviation of 10 kHz, and 0.88 mrad for a 0.1 radian modulation index, respectively.

Theory of Uncertainty Analysis with Application to Naval Hydrodynamics

The modern methodology for quantifying the quality of experimental data is uncertainty analysis. Current methods are reviewed with some examples primarily from naval hydrodynamics. The methods described are applicable to fluids engineering. The history of uncertainty analysis, US and international standards on uncertainty analysis, verification and validation standards for computational fluid dynamics, and instrument calibration are discussed. One important result is that random loading in force calibration can produce a lower uncertainty estimate than sequential loading. Statistically, the calibration results for the slope and intercept are the same for the two methods in the example thrust calibration, but the uncertainty in random loading is factor of three smaller than sequential loading.

The configurations of HRM bundles in MNCs by their contributions to subsidiaries’ performance and cultural dimensions

The main goal of the paper is to determine whether the HQs of MNCs evaluate the significances of particular HRM subfunctions to their foreign subsidiaries’ performance differently depending on a specific cultural context and—as a consequence—various configurations of HRM subfunctions may be identified in different cultural contexts. The theoretical assumptions are based on a combination of the configurational and contextual perspectives through a cross-cultural lens. In the empirical research an abductive reasoning process is applied. The research sample covers 200 headquarters of MNCs. To analyze the collected data both descriptive and correlational statistical methods are used. Two patterns of configurational bundle of HRM have been identified: A and B. Pattern A tends to be more system oriented and Pattern B more centralization oriented. Pattern A covers the subsidiaries which, with comparison to their HQ, are of lower power distance, higher individualism, higher masculinity, lower uncertainty avoidance, longer time orientation, and higher indulgence. Pattern B is composed of the subsidiaries with the opposite signs of the cultural distance index. The originality of the study consists in the application of the abductive research model. Thanks to it, we were able to search and find the simplest and most probable explanations for our observations. And the value of the research itself lies in the evidence that the contextual perspective with its configurational implications in the HRM research field is useful in identifying the phenomena that are difficult to identify or unidentifiable otherwise. The findings of the present study provide some knowledge on how cultural distance (external variable) and the significance of HRM to the subsidiary’s performance results (internal variable) interact in impacting on different configurational bundles of HRM subfunctions, their centralization practices and knowledge flows in MNCs.

Определение модуля упругости композиционной керамики на основе SiC

Young's modulus of composite heterophase SiC-ceramics with different phase ratios is determined on the base of two independent methods. The Voight-Reuss-Hill model is demonstrated to be applicable for calculation of the Young's modulus using measured characteristics of ceramic components. The calculation results are close to the results of independent dynamic indantation measurements. Lower uncertainty of Young's modulus is shown to be the advantage of the calculation method. At the same time, the application of this method requires additional measurements of ceramics composition and mechanical properties of all components.

Analysis of Runoff According to Application of SWMM-LID Element Technology (II): Parameter Uncertainty Analysis

This study quantitatively analyzed the degree of uncertainty associated with runoff based on the sensitivity analysis of runoff parameters using Low Impact Development (LID) element technology of study (I). Uncertainty was analyzed for parameter uncertainty, uncertainty of runoff, and uncertainty about the degree of parameter and runoff. Parameter uncertainty indices showed lower uncertainty indices as a whole and uncertainty indices of peak runoff were higher than that of total runoff in runoff uncertainty. The reason for this is that the LID element technology itself is intended to store low-frequency small-scale rainfall, so that the uncertainty index of peak rainfall seems to be highly uncertain. As a result of the analysis of uncertainty degree associated with runoff, it was found that the uncertainty of storage depth of bio retention cell and rain garden was low, while the heaviness parameters of rain barrel had the highest uncertainty index. In future experiments and research, it is necessary to modify the parameter range suitable for Korea, which will be helpful for urban development, reduction of nonpoint source pollution, and designing of low frequency rainfall storage facilities.