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This paper sets out to design and realize a highly linear, wide dynamic range and high switching efficiency integrated CMOS up‐conversion mixer for two‐step IEEE 802.1a WLAN transmitter application in 0.18‐μm deep submicron CMOS technology.

A folded current draining low‐voltage mixer architecture is explored and an extensive simulation carried out utilizing Cadence Spectre‐RF tool in optimizing the linearity, input third‐order intercept point (IIP3), the dynamic range, 1 dB compression point (P_−1dB), power dissipation and reduction of switching quad C_gs, input gate‐source capacitance, in enhancing the switching efficiency of the proposed architecture.

A highly linear, high input dynamic range, low voltage folded up‐conversion mixer architecture is realized in a significant comparable performance with respect to conventional reported architecture, indicating −8.87 dBm of OIP3 corresponding to 15.27 dBm IIP3 and 4.37 dBm of P_−1dB in 0.18‐μm CMOS technology.

The optimized mixer architecture is stringent to an up‐converter application. To be utilized as a down converter at the receiver end, parameters, namely as noise figure and conversion gain, are of additional importance.

The designed folded mixer architecture is in need of integration to a two‐step up‐conversion transmitter architecture which relaxes the injection pulling effect for a given low voltage headroom, with low power dissipation design.

In this work, an integrated folded architecture with on‐chip process, voltage and temperature compensated biasing circuit is explored and enhanced, raising awareness of adapting improved multiplier blocks in achieving optimal performance in WLAN transceiver architecture.

Most current modeling approaches identify very small gains from trade reform. In this chapter, we examine recent developments in the literature to assess whether standard modeling approaches are mis-specifying, understating, or overstating the gains from trade reform. Key areas where the impacts of trade barrier reduction appear to be understated include the measurement of barriers; the aggregation of these barriers; process productivity gains, particularly those resulting from reallocation of resources between firms; product quality improvements and expansion of product variety; factor supply; and investment of gains from trade.

In this paper, we critically review cost‐benefit analysis, cost‐effectiveness analysis and the guard‐rail approach as decision‐support tools for the choice of climate protection strategies. Our main focus is on the central role of value judgments, which arise from the need to value; first, uncertain environmental benefits from climate protection relative to other goods; second, the consumption of the present relative to future generations; and third the consumption of “poor” relative to “rich” people. Each of the three approaches analyzed has its shortcomings. Cost‐benefit analysis requires a complete and transitive preference ordering, which stands in sharp contrast to scientific uncertainties and valuation problems. Cost‐effectiveness analysis suffers from the difficulty of setting an appropriate climate protection target. Finally, the usefulness of the guard‐rail approach for decision‐makers depends on the extent to which it is possible to limit the choice set.

This chapter tests theoretically and empirically the existence of a stable relationship between energy consumption and CO2 emissions. Based on microeconomics and physics, a model has been specified and applied to annual data for twenty countries, which representing 61 percent of the world’s population in 2018, over the period 1995–2015. The data are from the International Energy Agency (2019) and econometric techniques including panel data and causality tests have been used. The results indicate that there is a causal relationship between energy consumption and CO2 emissions. In general, consumers cannot directly change emissions caused by production processes, but they can act on emissions caused by their own domestic energy consumption. Approximately three quarters of domestic energy consumption is due to heating and domestic hot water consumption. Taking into account the lower emissions and the lower economic cost of the initial investment, four potential energy systems have been selected for use in heating and domestic hot water. Their social returns have been assessed across nine of the twenty countries in the sample over a lifecycle of 25 years from 2018: France, Portugal, Ireland, Spain, Iceland, Germany, United Kingdom, Morocco and the United States. Cost-benefit analysis techniques have been used for this purpose and the results indicate that the use of thermal water, where applicable, is the most socially profitable system among the proposed systems, followed by natural gas. The least socially profitable systems are those using electricity.

Benefit–cost analysis took root in the U.S. at the federal level in the 1930s with the use of the method by the Army Corps of Engineers. It now is used widely by government agencies and research organizations. The practice has long been controversial, and it remains so. Some critics find the weaknesses of benefit–cost analysis to be so severe as to warrant abandoning its practice.

This paper presents new evidence that the error in estimating the economic welfare of a transport scheme can be very large. This is for two reasons. Firstly when cost changes are large the income effect can be significant. This means the change in consumer surplus is no longer a good estimate of the compensating variation — the true measure of welfare benefit. Secondly, in the presence of large cost changes estimating the change in consumer surplus using the Rule of Half can lead to large errors. The paper uses a novel approach based on stated choice and contingent valuation data to estimate the size of this error for the situation of the provision of fixed links to islands in the Outer Hebrides of Scotland.

This paper aims to clarify the predicting and compensating method of aeroplane assembly. It proposes modeling the process of assembly. The paper aims to solve the precision assembly of aeroplane, which includes predicting the assembly variation and compensating the assembly errors.

The paper opted for an exploratory study using the state space theory and small displacement torsor theory. The assembly variation propagation model is established. The experiment data are obtained by a real small aeroplane assembly process.

The paper provides the predicting and compensating method for aeroplane assembly accuracy.

This paper fulfils an identified need to study how the assembly variation propagates in the assembly process.

In this paper, an adaptive fuzzy sliding mode controller (AFSMC) is developed for the formation control of a team of autonomous underwater vehicles (AUVs) subjected to unknown payload mass variations during their mission.

A sliding mode controller (SMC) is designed to drive the state trajectories of the AUVs to a switching surface in the state space. The payload mass variation results in parameter variation in AUV dynamics leading to actuator failure. This further leads to loss of communication among the members of the team. Hence, an adaptive SMC based on fuzzy logic is developed to maintain the coordinated motion of AUVs with payload mass variation.

The results are obtained by employing adaptive SMC for AUVs with and without payload variations and are compared. It is observed that the proposed adaptive SMC exhibits improved performance and tracks the desired trajectory in less time even with variation in the payload. The adaptive fuzzy control algorithm is developed to handle variation in payload mass variation. Lyapunov theory is used to establish stability of AFSMC controller.

Perfect alignment is assumed between centres of gravity (OG) and buoyancy (OB), thus AUVs maintaining horizontal stability during motion. The AUVs’ body centres are aligned with centres of gravity (OG), thus the distance vector being rg = [0,0,0]T. As it is a tracking problem, sway motion cannot be neglected as the AUVs are travelling in a curved locus, hence susceptible to Coriolis and centripetal forces. The AUV is underactuated as only two thrusters at the stern plate that are employed for the surge and yaw controls and error in Y- direction are controlled by adjusting control input in surge and heave direction. Control inputs to the thruster are constants, and depth control is achieved by adjusting the rudder angle.

AUVs are employed in military mission or surveys, and they carry heavy weapons or instrument to be deployed at or picked from specific locations. Such tasks lead to variation in payload, causing overall mass variation during an AUV’s motion. A sudden change in the mass after an AUV release or pick load results in variation in depth and average velocity.

The proposed controller can be useful for military missions for carrying warfare and hydrographic surveys for deploying instruments.

A proposed non-linear SMC has been designed, and its performances have been verified in terms of tracking error in X, Y and Z directions. An adaptive fuzzy SMC has been modelled using quantized state information to compensate payload variation. The stability of AFSMC controller is established by using Lyapunov theorem, and reachability of the sliding surface is ensured.