A new SOLT calibration method for leaky on-wafer measurements using a 10-term error model

We present a new Short-Open-Load-Thru (SOLT) calibration method for on-wafer S-parameter measurements. The new calibration method is based on a 10-term error model which is a simplified version of the 16-term error model. Compared with the latter, the former ignores all signal leakages except the ones between the probes. Experimental results show that this is valid for modern vector network analyzers (VNA). The advantage of using this 10-term error model is that the exact values of all error terms can be obtained by using the same calibration standards as the conventional SOLT method. This avoids not only the singularity problem with approximate methods, such as least squares, but also the usage of additional calibration standards. In this paper, we first demonstrate how the 10-term error model is developed and then the experimental verification of the theory is given. Finally, a practical application of the error model using a 10 dB attenuator from 140 GHz to 220 GHz is presented. Compared with the conventional SOLT calibration method without crosstalk corrections, the new method shows approximately 1 dB improvement in the transmission coefficients of the attenuator at 220 GHz

A digital definition method for manufacturing model of aircraft integral panel

The manufacturing model of aircraft integral panel is presented based on the analysis of its structure and manufacturing process. The manufacturing model for each key process consists of model for processing and model for workpiece to bridge digital design and fabricating. Model for workpiece is used to express the target part information at the end of some operation. Model for processing is used to describe the intermediate state information, and it aims to attain but is different the workpiece because of process factors. The definition flow of the manufacturing model is given. The modeling approach of integral panel part blank from shot peen forming part model orienting to NC cutting is proposed and exemplified. It is analyzed that the approaches above can define the models accurately and totally to meet the needs of process planning , NC fabricating and inspecting

The Penetration of Virginia Woolf’s Life to Her Novel Mrs. Dalloway

Virginia Woolf, as one of the best known novelist and critic, has made great achievements in the development of the “stream of consciousness” school of modern literature. One of her most famous representative works Mrs. Dalloway has vividly demonstrated the beauty and attraction of stream of consciousness approach of literature creation. In this novel, a great deal of elements of the author’s life have been penetrated and embodied in the development of the story and the characters, represented by the family and social background, the attitude to literature, the influences of death as well as the understanding towards marriage and women. A glance at the influences of the author’s own life experiences on the characters she created may help the readers to have a better understanding towards this special kind of literary works, which is usually much less conspicuous in plot

The apple of China

An equity research involves analyzing a company’s financial information and forecasting it with the intention of making an investment recommendation of either buy or sell its stock. The goal of this paper is to analyze Xiaomi Corporation’s financial information, forecast the company’s value in the future and, though that, make an investment recommendation about whether it is better to buy or sell Xiaomi Corporation’s stock by comparing Xiaomi Corporation’s market stock price with its theoretical target price. For that effect, the DCF valuation method was applied and the investment recommendation was to buy Xiaomi Corporation’s stock

A study of students’ learning pathways on the buoyant force through the CoSci learning platform

The study of students’ learning pathways is necessary for teachers to understand how students learn. In learning or solving some problems, the students have their own strategy for constructing knowledge to learn and solve. During students’ learning, they will apply their previous knowledge to further create a body of knowledge. For example, students need to understand basic concepts related to the buoyant force – density, mass, volume, water level, weight, and depth – before solving the buoyancy problem (Wongsuwan & Huntula, 2019). Therefore, if teachers know how students learn, they can encourage and promote students to learn better. Teachers can also know what the difficulties for students in learning are. However, to study how students learn and learning pathways, is to study something inside a person. Yet, some students are not able to express their thoughts by speaking or writing, which makes it difficult to understand how they learn and their learning pathways. Therefore, it is a challenge for teachers to find appropriate ways and strategies to understand students' learning pathways validly. One of the reliable tools used to investigate students' conceptual understanding and students' learning pathways is the CoSci learning platform with an interactive computer simulation. The CoSci can be used to record students' behaviors such as students' answers, frequency of operating computer simulations, times, and date of interaction with the platform. Moreover, there is the Lag Sequential Analysis function (LSA) which is one of the functions of CoSci to calculate and display students' activity patterns, referred to as a learning pathway in this presentation. This study aims to investigate 1) students' learning pathways on the buoyant force, and 2) the relation between Predict-Observe-Explain (POE) activity performance and learning performance of eighteen students in eleventh grade in science classrooms of a university-affiliated school project (SCiUS), Khon Kaen University, Thailand. The focusing conception was the buoyant force and the basics conception related to the buoyant force which are mass (M), volume(V), density(D), the level of solution(L), submerged depth(H), and weight(W). The POE with the interactive computer simulation (i.e., the CoSci learning platform) was developed on the CoSci platform based on students' alternative concepts and used to facilitate students' conceptual understanding of the buoyant force (Wongsuwan & Huntula, 2021). In this study, the LSA was used to calculate and display students' learning pathways while students were learning on the CoSci meanwhile, Spearman's correlation was used to compute the correlation between the post-test score (learning performance) and the score of each step of the POE. The findings showed that the most difficult concept for students to learn about the buoyant force was the concept related to the mass of the object. This study identified two groups of students' learning pathways patterns on the buoyant force: 1) the V-M-W pattern, which is starting from the basic concepts of volume then mass, and weight consequently which facilitated students in learning the buoyant force; 2) the W-M-V pattern, which means student started to learn the basic concepts of weight then mass and volume consequently, that made students still confused in learning the buoyant force. Spearman's correlation showed a significant positive relationship between learning performance and explanation score (r=1.00, p<0.01) and a significant negative relationship between learning performance and the frequency of running the simulation (p<0.05). The implications of the findings are discussed in this presentation. REFERENCES Wongsuwan, W., and Hantula, J. (2019). The students’ basic conceptions of Buoyant force. Journal of Physics: Conference Series. 1380 012139. Wongsuwan, W., and Hantula, J. (2021). The interactive computer simulation and learning activity for facilitating students’ conceptual understanding on the buoyant force through the CoSci learning platform. Journal of Physics: Conference Series. 2145 012075

Weak turbulence theory of the non-linear evolution of the ion ring distribution

The nonlinear evolution of an ion ring instability in a low-beta magnetospheric plasma is considered. The evolution of the two-dimensional ring distribution is essentially quasilinear. Ignoring nonlinear processes the time-scale for the quasilinear evolution is the same as for the linear instability 1/t_ql gamma_l. However, when nonlinear processes become important, a new time scale becomes relevant to the wave saturation mechanism. Induced nonlinear scattering of the lower-hybrid waves by plasma electrons is the dominant nonlinearity relevant for plasmas in the inner magnetosphere and typically occurs on the timescale 1/t_ql w(M/m)W/nT, where W is the wave energy density, nT is the thermal energy density of the background plasma, and M/m is the ion to electron mass ratio, which has the consequence that the wave amplitude saturates at a low level, and the timescale for quasilinear relaxation is extended by orders of magnitude