Key Statistical Concepts: Non-Parametric Tests and Time Series Analysis
Non-Parametric Methods
Non-parametric methods are statistical tests that do not assume the data follows a specific distribution, such as the normal distribution. They are often used when the assumptions of parametric tests are violated.
- Mann-Whitney U Test (Wilcoxon Rank-Sum Test): Used to compare the distributions of two independent groups or samples to determine if they have different medians. It is an alternative to the independent samples t-test.
- Wilcoxon Signed-Rank Test: Used to compare the medians
Magnetic Properties of Materials: Paramagnetism and Ferromagnetism
PARAMAGNETISM
The atoms of paramagnetic substances possess permanent magnetic dipoles.
In the absence of external magnetic field, the atomic dipoles are distributed randomly throughout the paramagnetic material as shown in fig. (5.6a). The external field of individual atoms cancel each other’s effect and hence do not exhibit any magnetic properties in the absence of external magnetic field.
Now, when the substance is subjected to an external field B, each of the atomic dipole experiences a torque.
Read MoreClinical Shock: Diagnosis, Physiology, and Treatment
Understanding Clinical Shock
Shock is one of the most frequently diagnosed and most complex clinical conditions encountered in the critically ill patient. Ongoing investigations have identified the mechanisms of various shock states to be complicated, yet based within the cellular foundation of normal, everyday existence. Although mortality from shock states remains high, the focus on early, aggressive resuscitation to defined endpoints has significantly enhanced a clinician’s ability to improve
Read MoreMachine Learning Fundamentals: Models, Bias-Variance, Metrics
1. The Three Goals of Modeling
| Goal | Key Question | Example | Models |
| Prediction | “What will happen?” | Accurately flagging spam emails. | Random Forest, GBM, SVM |
| Attribution | “Why does this happen?” | Identifying which ad campaign had a significant impact on sales. | Logistic/Linear Regression |
| Estimation | “What is the true relationship?” | Modeling the true dose-response curve of a new drug. | Logistic/Linear Regression |
2. The Bias-Variance Tradeoff
Bias (Underfitting): Error from a model being too simple and making incorrect assumptions.
Earthquake Science: Faults, Waves, Measurement, and Hazards
*EARTHQUAKES:
-in plate boundries bc is where most jaults jostle, collide with, or slide past each other. Also in transform fault zones.
-fault: planar breaks and displacement happens
-fault plane: plane which displacement occurs
*stirke-
Slip
*reverse -> <-
*normal <- ->
-creep: if a displacement is gradual,smooth there is no seismic activity or earthquake (aseismic slip)
-earthquake:is displacement is quick, earthquake happens (seismic slip)
elastic rebound: two slides of the fault snap back
Read MoreArchitectural Innovations of the Great Mosque of Córdoba
The Double-Arch System
The innovative system of overlapping arches was designed to provide greater elevation for the prayer hall. A column is placed on top of a pillar, approximately 2 meters high, from which the upper arch springs. This design incorporates Visigothic-style horseshoe arches at the bottom, which act as straps to prevent collapse, a significant improvement over the simple beams or braces used previously.
Horseshoe Arch Characteristics
The horseshoe arch features a camber of one-third
Read MoreUnderstanding Neurodevelopmental and Learning Disorders
Articulation, Speech, and Language Impairments
Articulation Disorder
- Refers to problems making speech sounds and with phonological processing skills.
- Seen mostly in young children (preschool age).
- Diagnosed if children do not outgrow common articulation errors (e.g., “wabbit” instead of “rabbit;” “nana” instead of “banana”).
- May be more common in developmental disorders (e.g., autism), genetic syndromes (e.g., Down syndrome), hearing loss, illness, or neurological disorders (e.g., cerebral
Rationalism vs. Empiricism: Descartes’ Dualism and Locke’s Theory of Ideas
Descartes: Existence of Material Fact
The existence of God warrants the correspondence between being and knowledge. God is perfect because He is omnipotent.
Three Areas of Reality (Substances)
Descartes established three areas of reality. One area is identified with Extended Substance (Res Extensa), which is characterized by extension and motion. That is, the world is a physical entity that occupies space.
The Mechanistic Worldview
Descartes defines the world as mechanistic (a quantity of matter with
Read MoreCustomer Relationship Management (CRM): Types, Models, and Strategy
Customer Relationship Management (CRM) Defined
Customer Relationship Management (CRM) is an integrated information system used to plan, schedule, and control pre-sales and post-sales activities within an organization. CRM embraces all aspects of dealing with prospects and customers, including the call center, sales force, marketing, technical support, and field service.
The primary goal of CRM is to improve long-term growth and profitability through a better understanding of customer behavior. CRM
Read MoreContemporary Challenges in European Union Governance and Politics
EU Integration and Regional Autonomy Movements
Europe has witnessed two opposing developments: the deepening of EU integration and the simultaneous rise in regional autonomy movements within member states. At first glance, these trends may appear contradictory. However, both reflect broader transformations in governance and identity in response to globalization, economic restructuring, and the shifting role of the nation-state.
Thesis: EU integration and regional autonomy are not opposing forces but
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