Imperfect Power Research Articles

Abstract 1705: Spatial interrogation of tertiary lymphoid structures (TLS) in colorectal carcinoma (CRC) tumor microenvironment (TME) using the MultiOmyx࣪ assay

Abstract Immune checkpoint blockade (ICB) therapy has revolutionized the landscape of cancer therapy in multiple tumor types since Ipilimumab, the first ICB agent, was approved for the treatment of metastatic melanoma is 2011. Current predictive biomarkers for therapy response include PD-L1 expression, tumor mutational burden (TMB) and microsatellite instability (MSI) status. However, responses to ICB vary widely and these predictive markers have demonstrated imperfect predictive power to ICB therapy. For instance, half of microsatellite instability-high (MSI-H) colorectal carcinoma (CRC) patients do not respond to ICB immunotherapy. There is still a crucial need to identify and develop biomarkers predictive of outcome to ICB therapy. Tertiary lymphoid structures (TLS) have been observed in a variety of solid tumors in humans, and their presence is a favorable prognostic indicator for survival in a variety of solid cancers including CRC. Further, it was recently shown that the presence of mature TLS was associated with improved response rate to ICB and overall survival in patients with advanced tumors in a large retrospective study. In this study, we used a 17-plex MultiOmyx panel to detect TLS, explore TLS maturation stage and characterize the tumor microenvironment (TME) in 40 CRC patients with known MSI status. The 17-plex includes CD3, CD4, CD8, CD45RO, FOXP3, CD20, CD56, CD68, CTLA-4, PD1, PD-L1, CXCL13, PNAd, CD21, CD23, DC-LAMP and PanCK. Using this panel, we successfully detected different stages of TLS in these CRC samples. Using proprietary deep-learning-based image analysis algorithm (NeoLYTX), we quantified TLS’s in the CRC samples and classified them by maturation stage based on biomarker expression and spatial organization of immune cells. While there was no difference in the number of early TLS (E-TLS; characterized by CD3, CD20 and pNAd) between MSI-H and microsatellite-stable (MSS) CRC samples, more primary follicle-like TLS (P-TLS; defined by CD3, CD20 and CD21) and secondary follicle-like TLS (S-TLS; defined by CD3, CD20 and CD23) were observed in the MSI-H group than the MSS group. In particular, the abundance of mature S-TLS was significantly higher in MSI-H CRC samples. This 17-plex MultiOmyx assay provides a powerful tool to characterize the cellular composition and spatial organization of the tumor microenvironment. The panel enables quantification of TLS, PD-L1 expression and abundance of tumor infiltrating lymphocytes from one single FFPE slide. The rich datasets generated by the MultiOmyx assay can provide greater understanding of the immune contexture within the TME and deeper insights into the correlations between biomarkers. These findings may have broad application and help identify biomarker signatures with improved predictive performance to immune checkpoint inhibition efficacy in solid tumors. Citation Format: Harry Nunns, Erinn A. Parnell, Michael Lazare, Judy Kuo, Eric Leones, Flora Sahafi, Josette William, Qingyan Au. Spatial interrogation of tertiary lymphoid structures (TLS) in colorectal carcinoma (CRC) tumor microenvironment (TME) using the MultiOmyx࣪ assay [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1705.

Robust trajectory planning for UAV communication systems in the presence of jammers

Unmanned Aerial Vehicle (UAV) has emerged as a promising novel application for the Sixth-Generation (6G) wireless communication by leveraging more favorable Line-of-Sight (LoS) propagation. However, the jamming resistance by exploiting UAV’s mobility is a new challenge in the UAV-ground communication. This paper investigates the trajectory planning problem in an UAV communication system, where the UAV is operated by a Ground Control Unit (GCU) to perform certain tasks in the presence of multiple jammers with imperfect power and location information. To ensure the reliability of the GCU-to-UAV link, we formulate the problem as a non-convex semi-infinite optimization, aiming to maximize the average worst-case Signal-to-Interference-plus-Noise Ratio (SINR) over a given flight duration by designing the robust trajectory of the UAV under stringent energy availability constraints. To handle this problem efficiently, we develop an iterative algorithm for the solution with the aid of S-procedure and Successive Convex Approximation (SCA) method. Numerous results demonstrate the efficacy of our proposed algorithm and offer some useful designinsights to practical system.

Free vibration of imperfect sigmoid and power law functionally graded beams

In the present work, free vibration of beams made of imperfect functionally graded materials (FGMs) including porosities is investigated. Because of faults during process of manufacture, micro voids or porosities may arise in the FGMs, and this situation causes imperfection in the structure. Therefore, material properties of the beams are assumed to vary continuously through the thickness direction according to the volume fraction of constituents described with the modified rule of mixture including porosity volume fraction which covers two types of porosity distribution over the cross section, i.e., even and uneven distributions. The governing equations of power law FGM (P-FGM) and sigmoid law FGM (S-FGM) beams are derived within the frame works of classical beam theory (CBT) and first order shear deformation beam theory (FSDBT). The resulting equations are solved using separation of variables technique and assuming FG beams are simply supported at both ends. To validate the results numerous comparisons are carried out with available results of open literature. The effects of types of volume fraction function, beam theory and porosity volume fraction, as well as the variations of volume fraction index, span to depth ratio and porosity volume fraction, on the first three non-dimensional frequencies are examined in detail.

Increasing and Diminishing Returns – Africa’s Opportunity to Develop

Marshall’s observation also applies to today’s migration patterns: from countries where most activities are subject to constant or diminishing returns to countries whose key economic activities are subject to increasing returns to scale. Diminishing returns occur when one factor of production is limited by nature, which means that it occurs in agriculture, mining, and fisheries. Normally the best land, the best ore, and the richest fishing grounds are exploited first, and – after a point – the more a country specializes in these activities, the poorer it gets. OECD (2018) shows how this occurs in Chilean copper mining: every ton of copper is produced with a higher cost than the previous ton. In Alfred Marshall’s theory, the ‘Law of Diminishing Returns’ is juxtaposed with ‘The Law of Increasing Returns’, also called economies of scale. Here we find the opposite phenomenon; the larger the volume of production, the cheaper the next unit of production becomes. Traditionally economies of scale were mainly found in manufacturing industry, and increasing returns combined with technological change has for centuries been the main driving force of economic growth. Increasing returns creates imperfect competition, market power and large barriers to entry for challengers – companies or nations – making it difficult for them to enter these industries. In contrast to the rents produced under conditions of increasing returns, raw materials – commodities – on the other hand, are subject to perfect markets, and productivity improvements spread as lowered prices. This is the essence of the theory which explains why former World Bank Chief Economist Justin Yifu Lin was correct when he asserted that ‘Except for a few oil-exporting countries, no countries have ever gotten rich without industrialization first’ (Lin 2012 : 350).

Robust adaptive power control for cognitive radio networks

In this study, the problem of robust adaptive power control (PC) in an underlay cognitive radio network with multiple secondary users (SUs) and primary users (PUs) is considered. Due to the effects of uncertainties (i.e. estimation errors, delays), the optimal PC (resource allocation) cannot guarantee the quality of service of SUs and PUs under imperfect channel state information and interference power of PUs. A robust resource allocation problem is formulated to maximise sum throughput of SUs under individual power constraints and signal-to-interference-and-noise ratio constraints of SUs as well as interference temperature constraints of PUs, whereas channel uncertainties and interference uncertainties induced into the secondary system are modelled by multiplicative uncertainties. Under the worst-case approach, the problem is transformed into a geometric programming problem solved by Lagrange dual methods. The performance of the different algorithms and the impact of uncertainties are discussed according to several simulation results.

How Many Good and Bad Funds Are There, Really?

Building on the work of Barras, Scaillet and Wermers (BSW, 2010), we propose a modified approach to inferring performance for a cross-section of investment funds. Our model assumes that funds belong to groups of different abnormal performance or alpha. Using the structure of the probability model, we simultaneously estimate the alpha locations and the fractions of funds for each group, taking multiple testing into account. Our approach allows for tests with imperfect power that may falsely classify good funds as bad, and vice versa. Examining both mutual funds and hedge funds, we find smaller fractions of zero-alpha funds and more funds with abnormal performance, compared with the BSW approach. We also use the model as prior information about the cross-section of funds to evaluate and predict fund performance.

Robust secrecy beamforming for wireless information and power transfer in multiuser MISO communication system

In this paper, we study the max-min fairness for robust secrecy beamforming design in a multiuser MISO communication system with simultaneous wireless information and power transfer (SWIPT). In particular, the imperfect channel state information (CSI) and power splitting information receiver (IR) are taken into account. We model the design as an optimization problem which maximizes the minimum harvested energy among the multi-antenna energy receivers (ERs). Besides, both the secure communication requirement and the lowest electrical energy storage threshold at IR must be guaranteed in our formulated optimization problem. The considered max-min problem is non-convex and hard to tackle. By introducing the technique of semidefinite relaxation (SDR), we prove the tightness of this relaxation and obtain the global optimal solution of our original optimization problem. Moreover, a suboptimal beamforming design scheme is proposed with low computational complexity. Simulation results show that our proposed robust schemes are more efficient than other schemes in terms of energy harvesting and transmit power saving.

A description of the operative decision-making process of a power generating company on the Nordic electricity market

In a liberalised electricity market, power generating companies face various trading possibilities. In addition, they have to take scheduling decisions. Both kinds of decisions are affected by uncertainties, e.g. power plant outages, uncertain market prices for electricity or imperfect wind power forecasts. This paper presents an overview of the decision-making process of a power generating company on the Nordic electricity market and illustrates how uncertainties affect this process. As a power generating company’s return on investment arises—at least partly—from its trading and scheduling decisions, it is important to optimise those decisions. Therefore, selected optimisation models are listed in a condensed manner. The paper also includes a both detailed and comprehensive description of the market design in the Nordic countries.

Fashioning Luxury for Factory Girls: American Jewelry, 1860–1914

The production of jewelry offers a lens through which to examine the nature of creativity in a capitalist economy. The fashioning of decorative goods for wider sections of society in the second half of the nineteenth century allowed manufacturers to expand the size of their businesses, but only by sustaining strong connections with consumers and keeping track of buyers' changing desires. The outcomes of decisions affecting their enterprises were determined by the degree to which producers understood what their customers wanted. Entrepreneurial activity was critical to the formation of strategies for coping with the problem of scarce or imperfect information and limited market power. These strategies induced a process of creative destruction, whereby old ways of making things changed, and technology, labor, skills, and capital were recombined.

A Capacity Analysis Method for Uplinks in DS/CDMA Cellular Systems with Imperfect SIR-Based Power Control and Multipath Fading

The letter proposes a method to analyze the system capacity of uplinks with imperfect SIR-based power control in direct sequence/code division multiple access (DS/CDMA) cellular systems with the multipath fading. It considers the received signal-to-interference ratio (SIR) as a random variable due to imperfect SIR-based power control. Based on assumptions regarding the average received SIR, a set of linear equations for the average received power on each uplink is derived. An outage-based system capacity can be then obtained according to the feasibility of the average received power vector and the average bit error rate. Finally, by applying central limit theorem, a closed-form solution for system capacity is approximately derived. Results show that numerical results of the closed-form solution have a good match with simulation results, which supports the validity of the proposed capacity analysis method.

An Analytical Framework for Imperfect DS-CDMA Closed-Loop Power Control over Flat Fading

This letter presents an analytical framework for a performance analysis of the imperfect direct-sequence code division multiple access (DS-CDMA) closed-loop power control (CLPC) loop with loop delay, channel estimation error, and power control command bit error as the parameters under a Rayleigh flat fading environment. The proposed model is verified through a comparison between analytical results and simulation ones.

Performance analysis of imperfect closed-loop power control over Rayleigh fading

The performance of closed-loop power control in code division multiple access systems considering several non-ideal conditions such as multiple power control, group delays, channel estimation error, and power control command bit error probability is investigated.

Impact of multipath fading on throughput in cellular packet CDMA system

An analytical approach for the calculation of throughput in a cellular slotted CDMA system with imperfect fast power control is presented. Usually, imperfections in power control after despreading are modelled as a lognormal random variable. It has been shown that, in a fading channel, the standard deviation of this variable is a function of whether or not the mobile is communicating with the base station where the power is measured. It is shown that when this fact is not taken into account the throughput results obtained are too optimistic.

Policy Forum: The Diffusion of New Technology: Editorial Note

Explaining the determinants of economic growth, and the factors which drive differences in growth performance between countries has long been a preoccupation of economists; generating and sustaining growth has also been a major target of public policy. Both economists and policy makers have only been partially successful empirically estimated growth models are not as robust as we would like them to be, government policies are often more damaging than they should be. One thing which is clear, however, is that technical change is important to economic growth. Moreover, taking the Schumpeterian distinction between invention, innovation and diffusion we also know that it is the last of these which has the most decisive impact on economic welfare. In other words, it is not the invention of new products/processes, nor their initial commercial exploitation, which brings the major benefits, but rather their widespread use. This is especially true of process innovations. Notwithstanding this, the process of diffusion is not well understood, nor from a policy standpoint, well targeted. Invention and innovation have been researched far more extensively, and have been the subject of more policy discussion. In this Policy Forum we have two papers on the diffusion of new technology and the role of public policy, one by Paul Stoneman and Paul Diederen, and one byJ. S. Metcalfe. Stoneman and Diederen first provide an overview of the diffusion process and the rationale for intervention, and second look at actual diffusion policies and their impacts. After a brief discussion of the optimal diffusion path the authors examine in some detail three possible sources of market failure which could relate to the diffusion of new processes imperfect information, market power and externalities. Any one of these could result in investment in diffusion which is socially sub-optimal. In each case the authors identify potential instruments for dealing with market failure for instance standard setting in the case of imperfect information, patent protection in the case of market structure and public subsidies in the case of externalities. The authors emphasise the difficulty of specifying general rules, given that diffusion itself is nested in a broader context than the market for a single innovation. This broader context is taken up by Metcalfe in his paper which looks at technology policy from an evolutionary perspective. This perspective aims to provide insights into two processes that which determines the actual range of innovations introduced, and the process by which successful innovations survive and diffuse. Clearly the evolutionary approach sees innovation and