Implementing the panel event study

Many studies estimate the impact of exposure to some quasiexperimental policy or event using a panel event study design. These models, as a generalized extension of “difference-in-differences” designs or two-way fixed-effects models, allow for dynamic leads and lags to the event of interest to be estimated, while also controlling for fixed factors (often) by area and time. In this article, we discuss the setup of the panel event study design in a range of situations and lay out several practical considerations for its estimation. We describe a command, eventdd, that allows for simple estimation, inference, and visualization of event study models in a range of circumstances. We then provide several examples to illustrate eventdd’s use and flexibility, as well as its interaction with various native Stata commands, and other relevant community-contributed commands such as reghdfe and boottest.

Internal solitary waves propagation speed estimation in the northern-part of Lombok Strait observed by Sentinel-1 SAR and Himawari-8 images

Remotely sensed data, both Synthetic Aperture Radar (SAR) and optical sensors, significantly contribute to the study and understanding internal solitary wave (ISW) dynamics in the ocean. Pairs of SAR and optical sensors were analyzed to estimate the ISW propagation speed in the northern-part of Lombok Strait. ISW propagation speed estimation used an image from Sentinel-1 SAR and three image pairs of Himawari-8 on 29 October 2018 with a time difference of 409 minutes. Sentinel-1 wide-swath imagery (250 km x 400 km) from two adjacent scenes can provide information on multiple ISW packets evolution in the northern-part of Lombok Strait. ISW propagation speed estimation on Sentinel-1 SAR image using the simple estimation by measuring the interpacket distance and dividing by the semidiurnal tidal period. The high temporal resolution of the optical sensor from Himawari-8 can estimate the ISW propagation speed using two different approaches. ISW propagation speed estimation using the semidiurnal tidal period from Sentinel-1 and Himawari-8 showed almost similar values. Sentinel-1 estimation results are 2.69 m.s−1 (Lombok Strait) and 1.30 m.s−1 (northern-part area), Himawari-8 results are 2.52 m.s−1 (Lombok Strait) and 1.27 m.s−1 (northern-part area). ISW propagation speed variability in the northern-part of the Lombok Strait shown in this study.

Heart Disease Prediction Using Hybrid Random Forest Model Integrated with Linear Model

The objective of the paper is to throw light on few existing heart disease predicting approaches and proposes a Hybrid Random Forest Model Integrated with Linear Model (HRFMILM) for predicting and identifying the HDs at an early stage. Even though the linear model has simple estimation procedure, it is very sensitive to outliers and may lead to overfitting process. On the other hand, averaging in Random Forest Model (RFM) improves the overall accuracy and reduces the possibility of overfitting. The dataset is collected from standard UCI repository. Experimental results concluded that the integration of Linear Model with RFM makes the simple estimation procedure with improved overall accuracy than the respective models. Further, the proposed method compares the prediction performance of few existing approaches in terms of parameters, namely, precision, recall and F1-score.

PHYSICS OF MOSFET NANOTRANSISTORS: FUNDAMENTAL LIMITS AND RESTRICTIONS

In the last one from the series of the tutorial review articles, devoted to physics of modern nanotransistors and aimed to serve reseachers, ingeneers, students and teachers in the universities, it is demonstrated that the existence of the minimal energy for recording of 1 bite of information leads to fundamental restriction on minimal MOSFET channel length and on minimal time of transistor swithching. The obtained simple estimation Lmin = 1.2 nm (for room temperature) is somewhat lower, than in reality, and it looks like that Si FETs with a channel shorter than 2.5–3 nm would newer be fabricated. This correlates with the results of numerical modeling of electron transport through the channel, which demonstrate that for short channels the greater part of current passes by tunneling below the barrier top, and the transistor loses its functionality, because the current in source-drain circuit is no longer governed by gate voltage.

On the probability of lymph node negativity in pN0-staged prostate cancer—a theoretically derived rule of thumb for adjuvant needs

Purpose The extent of lymphadenectomy and clinical features influence the risk of occult nodes in node-negative prostate cancer. We derived a simple estimation model for the negative predictive value (npv) of histopathologically node-negative prostate cancer patients (pN0) to guide adjuvant treatment. Methods Approximations of sensitivities in detecting lymph node metastasis from current publications depending on the number of removed lymph nodes were used for a theoretical deduction of a simplified formulation of npv assuming a false node positivity of 0. Results A theoretical formula of npv = p(N0IpN0) = (100 − prevalence) / (100 − sensitivity × prevalence) was calculated (sensitivity and preoperative prevalence in %). Depending on the number of removed lymph nodes (nLN), the sensitivity of pN0-staged prostate cancer was derived for three sensitivity levels accordingly: sensitivity = f(nLN) = 9 × nLN /100 for 0 ≤ nLN ≤ 8 and f(nLN) = (nLN + 70) /100 for 9 ≤ nLN ≤ 29 and f(nLN) = 1 for nLN ≥ 30. Conclusion We developed a theoretical formula for estimation of the npv in pN0-staged prostate cancer patients. It is a sine qua non to use the formula in a clinically experienced context before deciding to electively irradiate pelvic lymph nodes or to intensify adjuvant systemic treatment.

Field Representation Microwave Thermography Utilizing Lossy Microwave Design Materials

In this contribution, we are investigating a technique for the representation of electromagnetic fields by recording their thermal footprints on an indicator material using a thermal camera. Fundamentals regarding the interaction of electromagnetic heating, thermodynamics, and fluid dynamics are derived which allow for a precise design of the field illustration method. The synthesis and description of high-loss dielectric materials is discussed and a technique for a simple estimation of the broadband material’s imaginary permittivity part is introduced. Finally, exemplifying investigations, comparing simulations and measurements on the fundamental TE10-mode in an X-band waveguide are presented, which prove the above introduced sensing theory.