Philosophical skepticism about the external world is a philosophical view that questions our knowledge of the propositions that are about the external world. Some versions of philosophical skepticism use skeptical hypothesis to prove that we can’t know anything about the external world. One of the most famous skeptical hypothesis is the brain in a vat hypothesis. Putnam is the first philosopher who has tried to show that accepting semantic externalism refutes this kind of skepticism. Semantic externalism is the view that the meaning of a term in our language, or the content of our psychological state, is at least partially determined by factors that are external to the speaker. Putnam's argument seems to be epistemically circular; so it can't show that we know that we are not brains in a vat. By introducing new externalist arguments, Brueckner has tried to solve this problem. The evaluation of Bruckner’s simple arguments in refuting the skepticism is the main purpose of this paper. Having analyzed these arguments, it has shown that these arguments can’t prove that we can have knowledge about the external world. But Brueckner’s compatibilist argument shows that we can have justified believes about the external world.

In recent years, laser drilling is used as a new process for micro drilling with high precision, less time and high aspect ratio in various industries, particularly in the aerospace industry. To improve the quality of drilling process, identification of the process parameters and investigation of their influence on the output characteristics are necessary. In present study, laser percussion drilling process was performed on Hastelloy X nickel-based superalloy and the effect of process parameters including laser frequency, pulse width and laser beam keeping time was investigated on the hole geometry characteristics (hole entrance and exit diameter, hole entrance and exit Circularity and hole taper). The results indicate that by increasing the laser frequency, hole entrance and exit diameter increases but hole entrance and exit Circularity and hole taper decrease. By increasing the pulse width, hole entrance and exit diameter increases but hole entrance and exit Circularity decreases. Also, with increasing the pulse width, hole taper decreases. When the laser beam keeping time increases, hole entrance and exit diameter increases but hole entrance and exit Circularity and hole taper decrease.

Effective watershed management is crucial for mitigating natural hazards and necessitates the evaluation and prioritization of sub-watersheds. This study prioritizes the sub-watersheds of the Anjerd watershed in East Azerbaijan Province for soil and water conservation interventions through morphometric parameter analysis. Given the lack of high-resolution Digital Elevation Model (DEM) data for the study area, topographic maps at a 1:25,000 scale were utilized to generate a digital elevation model and conduct morphometric analysis. Fifteen morphometric parameters influencing flood risk, erosion, and sedimentation were extracted, including drainage density, bifurcation ratio, stream frequency, drainage texture ratio, length of overland flow, Circularity ratio, form factor, elongation ratio, compactness coefficient, infiltration number, maintenance coefficient, mean slope, ruggedness number, relative relief ratio, and hypsometric integral. Each sub-basin was ranked from 1 to 11 based on individual morphometric parameter values, and an average ranking was used to determine overall prioritization. To refine the analysis and reduce dimensionality, Principal Component Analysis (PCA) was employed, effectively narrowing the parameters to six key indices: drainage density, Circularity ratio, bifurcation ratio, stream frequency, compactness coefficient, and hypsometric integral. The prioritization results obtained from all 15 parameters aligned with those derived from the key indices, validating the effectiveness of PCA in sub-basin prioritization. According to the prioritization outcomes, sub-basin A1-4 exhibited the highest priority for management interventions due to its lowest average rank, whereas sub-basin A5 had the lowest priority. These findings provide a strategic basis for decision-making, aiming to reduce sediment inflow into the Emarat Dam reservoir and mitigate flood-related damage.

The current paper develops three different ways to measure the multi-period global cost efficiency for homogeneous networks of processes when the prices of exogenous inputs are known at all time periods. A multi-period network data envelopment analysis model is presented to measure the minimum cost of the network system based on the global production possibility set. We show that there is a relationship between the multi-period global cost efficiency of network system and its subsystems, and also its processes. The proposed model is applied to compute the global cost Malmquist productivity index for measuring the productivity changes of network system and each of its process between two time periods. This index is circular. Furthermore, we show that the productivity changes of network system can be defined as a weighted average of the process productivity changes. Finally, a numerical example will be presented to illustrate the proposed approach.

The quarry operators and managers are having a running battle in determining with precision the rate of deterioration of the button of the drill bit as well as its consumption. Therefore, this study is set to find the best-performing model for predicting the drill bit button's wear rate during rock drilling. Also, the rate at which drill bit buttons wear out during rock drilling in Ile-Ife, Osogbo, Osun State, and Ibadan, Oyo State, Southwest, Nigeria was investigated. Artificial Neural Network (ANN), Adaptive Neuro-Fuzzy Inference System (ANFIS), and adaptive moment Estimation-based Long Short-Term Memory (LSTM) machine learning approaches were used to create models for estimating the bit wear rate based on Circularity factor, rock grain size, equivalent quartz content, uniaxial compressive strength, porosity, and abrasive properties of the rock. The performance of the models was measured using a new error estimation index and four other convectional performance estimators. The analysis of performance shows that the adaptive moment estimation algorithm-based LSTM model did better and more accurately than the other models. Thus, the LSTM models presented can be used to improve drilling operations in real-life situations.

One of the ways in which Avicennian logic is different from the other logical systems, is in the definition of propositions. In Avicennian logic, a proposition is a speech which we can truly say the speaker is true or false in what she has said. But in other logical systems, truth and falsehood are properties of propositions themselves. In the present article, we attempt to present a new explanation of this feature of Avicennian logic to determine its superiority over other logical systems. According to this explanation, Avicenna’ s reasons for the definition are (i) he sought to provide a criterion for identifying propositions to avoid the problem of Circularity in defining the propositions; and (ii)Since Avicenna considers not the potential proposition but the actual proposition as the primary bearer of truth, he attributes truth and falsehood to the speaker of the actual proposition, i. e., the person who utters the sentence.

The problem of the hermeneutical circle is one of the contentious issues in philosophical hermeneutics. This paper, begins with focusing on the question as to whether what hermeneuts mean by a hermeneutical circle is in fact a real circle with no analogical sense involved. Recognizing that this problem is not confined to the relation between part and whole, this study confines itself to explore the problem of the hermeneutical circle with regard to the Circularity between part and whole in a sentence. I will argue that, as far as the interdependence between part and whole of a sentence is concerned, there is no real Circularity between them. This will be followed by scrutinizing the source of such a misunderstanding, i.e., the circular interdependence between understanding the part and the whole of a sentence. I will present my analysis through a critical reading of two contemporary hermeneuts, Eric Donald Hirsch and Graeme Nicholson, even though both are on the right track in questioning the existence of such a circle in the first place. The argument presented could apply to contexts well beyond that of the Circularity between part and whole in a sentence.