Key Performance Parameters Research Articles

Refining Operational Vertical Mobility


 Environmental hazards have an unrecognized and unmet influence on operations. The mistranslation of vertical access and rescue customs and practices, to an environment with uncertain and unrecognizable hazards, can lead to catastrophic failure. Application of these customs and practices to meet the complex operational constraints and environmental hazards central to high-hazard mission sets, has persisted and confused operational vertical rescue teams. Improvised approaches, using minimal but readily available equipment, can close gaps between theory and practice and between discrete concepts in a continuously evolving environment. This paper addresses existing gaps in operational vertical response utilizing a context-specific approach similar to the authors of the original Tactical Combat Casualty Care (TCCC) project published in the 1996 supplement of Military Medicine (Butler FK, 1996).
 
 A pragmatic framework is introduced, which has been evolving for the past 10 years within USSOCOM, Federal special operations teams, and municipal special response elements termed Operational Vertical Mobility (OVM). Operational Vertical Mobility (OVM) creates an adaptable model within high-hazard vertical response in the same manner that TCCC disrupted prehospital tactical medicine (Butler FK Jr, 2007). Since normative traditional civilian vertical practices do not translate well into the context of a Volatile, Uncertain, Complex, Ambiguous, Threat containing, and Time-compressed (VUCA-T2) environment, OVM reframes vertical response key performance parameters (KPP’s) in opposition to traditional design principles. OVM promotes creating theories out of practice rather than forcing theories into practice. In order to appraise the key performance parameters of verticality within a VUCA-T2 environment, a panel of practitioners with expertise across multiple vertical disciplines and specialized units analyzed relevant guidelines, principles, industry recommendations, nonlinear sciences, and high reliability organizational characteristics for successful operational application.

Understanding of Blast Furnace Performance with Biomass Introduction

The blast furnace still dominates the production and supply of metallic units for steelmaking. Coke and coal used in the blast furnace contribute substantially to CO2 emissions from the steel sector. Therefore, blast furnace operators are making great efforts to lower the fossil CO2 emissions and transition to fossil-free steelmaking. In previous studies the use of pre-treated biomass has been indicated to have great potential to significantly lower fossil CO2 emissions. Even negative CO2 emission can be achieved if biomass is used together with carbon capture and storage. Blast furnace conditions will change at substantial inputs of biomass but can be defined through model calculations when using a model calibrated with actual operational data to define the key blast furnace performance parameters. To understand the effect, the modelling results for different biomass cases are evaluated in detail and the overall performance is visualised in Rist- and carbon direct reduction rate (CDRR) diagrams. In this study injection of torrefied biomass or charcoal, top charging of charcoal as well as the use of a combination of both methods are evaluated in model calculations. It was found that significant impact on the blast furnace conditions by the injection of 142 kg/tHM of torrefied biomass could be counteracted by also top-charging 30 kg/tHM of charcoal. With combined use of the latter methods, CO2-emissions can be potentially reduced by up to 34% with moderate change in blast furnace conditions and limited investments.

Modelling of leakages in rotary twin-screw compressor

The adiabatic and volumetric efficiencies are key performance parameters of any positive displacement machines including twin screw compressors. These efficiencies are affected by clearances and leakages in these machines. The leakage happen because of clearance gap and pressure difference between two pressurized chambers the compression module. In this work, findings from all the numerical and mathematical models are presented for different leakages in the twin-screw compressor. Authors proposed an iterative method to estimate the leakages by taking in account the geometry of the clearance, friction and local resistances. An experimental set up to collaborate the leakage model is presented, which can be used for further investigation of these leakages.

Attenuated Chamber-Pressure Signal Reconstruction Using Maximum-Likelihood Estimation and Optimal Deconvolution

Chamber pressure, as it develops during rocket combustion, strongly correlates with many of the internal motor ballistic properties, including combustion stability, fuel regression rate, and mass flow. Chamber pressure is also an essential measurement for calculating achieved thrust coefficient and characteristic velocity. Because of the combustion environment hostility, sensing chamber pressure with high fidelity presents a difficult measurement problem, especially for solid and hybrid rocket systems, where combustion by-products contain high amounts of carbon and other sooty materials. These contaminants tend to deposit within the pneumatic tubing used to transmit pressure oscillations from the thrust chamber to the sensing transducer. Partially clogged transmission tubes exhibit significant response latency and damp high-frequency pressure oscillations that may be of interest to the testers. A maximum-likelihood method for fitting a second-order model to chamber-pressure response is presented. The resulting model is subsequently used to reconstruct a high-fidelity motor response via optimal deconvolution. The method is applied to small hybrid-thruster results from three separate testing campaigns. Key performance parameters, such as thrust coefficient, characteristic velocity, and specific impulse, are recalculated using the reconstructed data. Results are compared to the unreconstructed data and are shown to exhibit consistently better agreement with theoretical predictions.

THz-driven split ring resonator undulator

We propose a short period undulator based on the electromagnetic field pattern in a THz-driven split ring resonator structure. An analytical model is developed that allows us to assess the key performance parameters of the undulator and to estimate the emitted radiation spectrum. Different geometric configurations are compared in detail using numerical simulations. A 100 MeV electron bunch with 5 pC charge is shown to emit narrow band 83 eV photon pulses with a peak brightness of approximately ${10}^{19}\text{ }\mathrm{photons}/(\mathrm{s}\text{ }{\mathrm{mrad}}^{2}\text{ }{\mathrm{mm}}^{2}\text{ }\text{ }0.1%\text{ }\text{ }\mathrm{BW})$ when passing through the 100 mm long undulator with a 1 mm period.

Effective Reusable Cleanroom Garments and Evaluation of Garment Life

Cleanroom garments are used to control the airborne dispersion of contamination from people into the cleanroom. The effectiveness of the garment in controlling the dispersion of contamination is a function of the fabric and design of garments, and test methods used to ascertain the effectiveness of garments are discussed in this article. These test methods can be used when choosing garments for use in a cleanroom but were used in this article to determine the deterioration of garments through use. Cleanroom garments were subjected to increasing numbers of decontamination cycles, which included sterilisation by gamma radiation, up to a maximum of 70. At defined number of decontamination cycles, the garment’s fabric was compared to a new fabric by visual examination, by a scanning electron microscope, and by physical tests of key performance parameters. It was concluded that the performance of the fabric remained acceptable up to 50 decontamination cycles. This conclusion was supported by the low dispersion rate of particles and microbe-carrying particles in a dispersal chamber from personnel wearing the garments. After 50 decontamination cycles, a low dispersion rate of 0.2/s of microbe-carrying particles from personnel wearing the garments was obtained and a 194-fold reduction in the microbial dispersion rate compared to cleanroom undergarments. Key words: cleanroom garments, garment life, contamination control

Determination of Lithium Diffusion Coefficients in Single Battery Active Material Particles by Using an AFM-Based Steady-State Diffusion Depolarization Technique

In lithium-ion batteries (LIBs), the ambipolar diffusion coefficient of lithium in the active material particles of the composite electrodes is a key parameter for the battery performance. Because conventional intermittent titration techniques (PITT/GITT) for determining the Li diffusion coefficient do not yield reliable values for composite electrodes, it is important to develop alternative methods. Here, we present a novel AFM-based technique for determining the Li diffusion coefficient of single active material particles in composite electrodes. The technique is based on creating a local Li diffusion polarization around the AFM tip and by subsequently monitoring the depolarization by AFM-based surface potential measurements. The analysis of the measurement results is supported by 3D diffusion simulations. Measurements on a single LiCoO2 particle inside a composite electrode yield a Li ambipolar diffusion coefficient of 8 × 10–13 cm2/s at 25 °C, which is in good agreement with results obtained from PITT/GITT measurements on homogeneous LiCoO2 thin films. The activation energy of the Li ambipolar diffusion coefficient is 0.41 eV.

MODELING OF THE OPTIMAL STRUCTURE OF MEAT PROCESSING ENTERPRISES

In today’s economic conditions, problems of functioning of domestic enterprises are not limited by lack of sources of financing of assets, but also often associated with inefficient investment in specific components of property, which adversely affects the level of economic efficiency of Ukrainian enterprises and the development of the economy as a whole.
 An important factor in making sound, rational and sound decisions about asset management is to improve existing or develop fundamentally new methods and models for optimizing the structure of assets of Ukrainian enterprises using criteria that are most relevant to current economic requirements, environmental challenges and internal objectives.
 In view of the above, the article demonstrates a clear dependence of the structure of the assets of the enterprise and the key indicators that characterize the effectiveness of its management. The optimal structure of assets for the studied enterprises and possible ways of their achievement are offered taking into account the defined criteria. A comparative assessment of the assets structure of the surveyed enterprises before and after optimization was carried out and on this basis the latter was confirmed by comparing the key parameters of the enterprise performance — profit and market value.
 A clear sequence of stages of the asset structure optimization model is proposed and described, along with methodological aspects of determining the effective structure of assets, the feasibility of its practical application at Ukrainian enterprises is proved through the achievement of the key goal of the enterprise activity — maximization of market value and profit.

Ultrathin Lensed Photonic Crystal Fibers with Wide Bandwidth and Long Working Distances

We have demonstrated an effective approach to fabricating ultrathin lensed photonic crystal fibers (PCFs) with long working distances. The analytic function of the maximum working distance of lensed PCF has been first revealed, agreeing well with the numerical solutions. Our specific lensed PCF can be experimentally optimized in terms of the collapsed PCF length and fiber tip curvature by use of a graphite filament furnace. A maximum collimating working distance up to 4.84 mm for a lensed PCF with the diameter of 125 μm is demonstrated, which is more than four times as long as previous lensed PCFs. The ultrawide working bandwidth over 770 nm is also demonstrated. The significantly enhanced features in terms of key performance parameters such as working distances and bandwidth will accelerate a variety of applications using such ultrathin lensed PCFs.

Lasers for Satellite Uplinks and Downlinks

The use of Light Amplification by Stimulated Emission of Radiation (i.e., LASERs or lasers) by the U.S. Department of Defense is not new and includes laser weapons guidance, laser-aided measurements, and even lasers as weapons (e.g., Airborne Laser). Lasers in the support of telecommunications is also not new. The use of laser light in fiber optics has shattered thoughts on communications bandwidth and throughput. Even the use of lasers in space is no longer new. Lasers are being used for satellite-to-satellite crosslinking. Laser communication can transmit orders-of-magnitude more data using orders-of-magnitude less power and can do so with minimal risk of exposure to the sending and receiving terminals. What is new is using lasers as the uplink and downlink between the terrestrial segment and the space segment of satellite systems. More so, the use of lasers to transmit and receive data between moving terrestrial segments (e.g., ships at sea, airplanes in flight) and geosynchronous satellites is burgeoning. This manuscript examines the technological maturation of employing lasers as the signal carrier for satellite communications linking terrestrial and space systems. The purpose of the manuscript is to develop key performance parameters (KPPs) to inform the U.S. Department of Defense initial capabilities documents (ICDs) for near-future satellite acquisition and development. By appreciating the history and technological challenges of employing lasers, rather than traditional radio frequency sources for satellite uplink and downlink signal carriers, this manuscript recommends ways for the U.S. Department of Defense to employ lasers to transmit and receive high bandwidth, and large-throughput data from moving platforms that need to retain low probabilities of detection, intercept, and exploit (e.g., carrier battle group transiting to a hostile area of operations, unmanned aerial vehicle collecting over adversary areas). The manuscript also intends to identify commercial sector early-adopter fields and those fields likely to adapt to laser employment for transmission and receipt.

The Roadheader Auto-Rectification Dynamic Analysis and Control Based on the Roadway Floor Mechanic Characteristics

The auto-rectification of the roadheader is one of the most key steps in the roadway auto-cutting progress, and the performance of the roadheader rectification on the mechanized excavation faces the key performance parameter. The determination of the roadway floor mechanical parameter is the big challenge and difficulty to the automation excavation of the roadheader. Combined the component of the roadway floor mechanical property and experiment parameters for the mechanical parameters regression equation, the floor mechanical parameter formula can be got, which is accurate and could be utilized in calculating the resistance. Analyzing the finite element part on the compaction resistance and steering resistance of the roadheader track, the accurate and reliable dynamic model of the roadheader rectification can be built. Combined with the roadheader’s structure and motion characteristic, the neural net PID(Proportion Integration Differentiation)control method is proposed which can real-time adjust the control parameters. Then the dynamic model and control method are simulated by MATLAB and the control method is tested by the roadheader control experiment system. Based on the experiment result, the designed control system can well meet the control requirements, fast response, small overshoot and better stability, which could ensure the good dynamic performance of the roadheader and the cutting quality of the roadway. It could be the theoretical basis and important technical support for the intelligent mining of coal mine.

Recent Advancements in Quasi-Isotropic Antennas: A Review

Quasi-isotropic antennas are promising candidates due to their applications in modern communication systems, where full spatial coverage and/or uniform signal reception is required. In this work, an in-depth review of quasi-isotropic antennas is presented, with the aim of understanding the working principles of such antennas and presenting the recent advancements, challenges, and solutions offered by various researchers. First, different design techniques adopted to achieve quasi-isotropic patterns, such as the use of complementary dipoles, multiple monopoles or dipoles, and an array of discrete elements are discussed. Then, different types of quasi-isotropic antennas—for example, planar, electrically small, 3-D printed, dual-band/wideband, circularly polarized, metamaterial-inspired, and dielectric resonator-based quasi-isotropic antennas—are revisited. Their applications in various technologies, such as RFID, energy harvesting, wireless sensor networks, and the IoT, are briefly explained. Lastly, different key performance parameters, such as complexity of configuration, design approach, physical profile, far field and radiation characteristics, reflection coefficients, operating frequency and bandwidth, gain deviation, and fabrication process, are discussed and tabulated. This review not only provides a guideline but will also help antenna engineers in designing a quasi-isotropic antenna with desirable performance.

Carbohydrase and Phytase Can Compensate Net Energy, Digestible Amino Acids and Available Phosphorus for High-performing Pigs

Two experiments were conducted to evaluate the efficacy of carbohydrases and phytase to compensate three key nutrients (NE, DAA and avP) for growing-finishing pigs. In Exp. 1, 112 pigs with average live weight 20.7 kg were randomly allocated to 4 dietary treatments, fed on commercial multi-grain diets containing total NSPs 12-15% with added phytase (500 FTU/kg), to examine the effect of two types of carbohydrase enzymes (single xylanase or multi-carbohydrase complex) to compensate NE and DAA: T1, Positive Control (PC); T2, negative control (NC1, PC minus 2% NE and 3% DAA); T3, NC1+ Multi-carbohydrases; and T4, NC1 + Single xylanase. In Exp. 2, 72 pigs averaged 20.7 kg live weight were randomly allocated to 3 dietary treatments: T5, Positive Control (PC, with added phytase); T6, NC2 negative control (PC minus 2.5% NE, 3.2% DAA, and 0.17 pcu avP, without added phytase); T7, NC2 + Multi-enzyme complex (carbohydrases + phytase). The pigs of both studies were reared for 3 phases: Grower 1 20-50 kg, Grower 2 50-75 kg, and Finisher (76-100 kg). The key performance parameters were measured and compared. The results of Epx. 1 showed, the pigs (PC) grew from 20 kg to 100 kg at average daily gain (ADG) close to 1 kg and FCR 2.30, and the reduction of nutrients (NC1) impaired growth rate mostly during the finishing phase (feed intake P=0.07, FCR P=0.09), and supplementation with both NSPase preparations tended to improve FCR over the NC1 with no differences observed between the two types of NSPase. In Exp. 2, the reduction of the three key nutrients clearly suppressed performance, namely lower weight gain (P<0.05) and higher FCR (P<0.05). The supplementation of multi-enzyme preparation partially restored performance with no significant differences from PC and NC2. In conclusion, for high performing pigs, carbohydrases can play a positive role in diets that already contain added phytase, and the contribution of the NSPase and phytase complex appear to be age related, and can be extrapolated as NE 40, 50 and 60 kcal/kg, respectively for Post-weaning, Grower and Finisher phases, and digestible amino acids 2-3% and avP 0.17% are for all phases. The enzyme supplementation showed no impact on feed intake.

Covalent organic frameworks as multifunctional materials for chemical detection.

Sensitive and selective detection of chemical and biological analytes is critical in various scientific and technological fields. As an emerging class of multifunctional materials, covalent organic frameworks (COFs) with their unique properties of chemical modularity, large surface area, high stability, low density, and tunable pore sizes and functionalities, which together define their programmable properties, show promise in advancing chemical detection. This review demonstrates the recent progress in chemical detection where COFs constitute an integral component of the achieved function. This review highlights how the unique properties of COFs can be harnessed to develop different types of chemical detection systems based on the principles of chromism, luminescence, electrical transduction, chromatography, spectrometry, and others to achieve highly sensitive and selective detection of various analytes, ranging from gases, volatiles, ions, to biomolecules. The key parameters of detection performance for target analytes are summarized, compared, and analyzed from the perspective of the detection mechanism and structure–property–performance correlations of COFs. Conclusions summarize the current accomplishments and analyze the challenges and limitations that exist for chemical detection under different mechanisms. Perspectives on how future directions of research can advance the COF-based chemical detection through innovation in novel COF design and synthesis, progress in device fabrication, and exploration of novel modes of detection are also discussed.

LoRa Network Planning and Deployment: A Terrestrial Navigation Application

Long Range (LoRa) is a popular low power wide area network (LPWAN) technology which operates in the Industrial, Scientific and Medical (ISM) frequency band transmitting information over ranges in excess of 20 km and 5 km in rural and urban landscapes respectively. This is of significance in applications where LoRa may be used as a terrestrial navigation system, or in any wireless sensor network (WSN) applications. A key system performance parameter for network planning and coverage prediction in ranging applications is the horizontal dilution of precision (HDOP). HDOP, is dependent on transmitter geometry and can amplify the position errors depending on how the transmitters are placed with respect to one another. Despite the importance of HDOP, there is no prescribed transmitter or gateway placement technique in the literature that has been combined with HDOP to obtain good position fixes within the coverage area. We propose a gateway placement technique called imaginary triangular tessellation technique to be used in conjunction with HDOP. The HDOP performance of our proposed technique is compared against three other placement techniques, namely naive, Deluany and random placement for the same number of gateways using the total average HDOP score of the area where a method has been deployed, as well as statistical significance and effect size as tests. The goal of our experiment is to find a placement technique that results in a better HDOP score (values between 0 and 1) in most parts of the coverage area. The HDOP scores for the random, Delauny, naive and our proposed technique are 30%, 50% 47% and 70% respectively for 8 gateways. The results also suggest that at least 8 LoRa gateways are needed to service our chosen geographical area of 2500 hectares or 6175 federation football fields. The results demonstrate that our proposed method can be used to set up and plan a LoRa network for use in scenarios such as tracking of animals, vehicles and navigation.

Metrology of convex-shaped nanoparticles via soft classification machine learning of TEM images.

The shape of nanoparticles is a key performance parameter for many applications, ranging from nanophotonics to nanomedicines. However, the unavoidable shape variations, which occur even in precision-controlled laboratory synthesis, can significantly impact on the interpretation and reproducibility of nanoparticle performance. Here we have developed an unsupervised, soft classification machine learning method to perform metrology of convex-shaped nanoparticles from transmission electron microscopy images. Unlike the existing methods, which are based on hard classification, soft classification provides significantly greater flexibility in being able to classify both distinct shapes, as well as non-distinct shapes where hard classification fails to provide meaningful results. We demonstrate the robustness of our method on a range of nanoparticle systems, from laboratory-scale to mass-produced synthesis. Our results establish that the method can provide quantitative, accurate, and meaningful metrology of nanoparticle ensembles, even for ensembles entailing a continuum of (possibly irregular) shapes. Such information is critical for achieving particle synthesis control, and, more importantly, for gaining deeper understanding of shape-dependent nanoscale phenomena. Lastly, we also present a method, which we coin the “binary DoG”, which achieves significant progress on the challenging problem of identifying the shapes of aggregated nanoparticles.

The Optimization of the Running Technique using Video Analysis Method

Systematic and continuous monitoring of athletic performance for the purpose of developing incrementally adaptive optimized training solutions is often presented as the future of more efficient training systems. This is a shared view in the specialty literature, with authors such as Lyle J (2005, p. 21) stating that “operational training implies the existence of a continuous monitoring process, not only within a competition but also within the training and preparation”. The periodic analysis of key performance parameters with a great effect on performance during a sports contest is a process based on a coherent, self-adaptive and continuously developing system, being the result of a a systemic analysis mechanism that focuses on the analytical evaluation, data collection and analytics, interpreting, and reporting the information obtained as a result of the research. Our approach is to apply and expand on the video analysis method by focusing on certain key questions: how much, how well, how precise but with what costs, with what effort, with what efficiency. Eliminating the “traditional” methods prompt the conclusions that using advanced mechatronic devices render us capable continuous monitoring, recording, and developing comparison solutions that enable concrete interventions on improving the technical execution of various athletic events and more.

Panorama Image Based Code-Free Programming of Robotic Operations

Increased demand for flexibility typical for most SMEs requires more flexible and skillful robots as well as improved means of interaction to simplify programming. For (semi-) automatic image-based derivation of robot programs for objects with large geometric dimensions systems are required that have an appropriately large range of motion and also provide image fusion methodology to cover the whole workspace.This document describes a software toolchain that can be used to acquire panoramic images, extract possible targets and paths for process tools. It also describes an experiment used to measure key performance parameters for comparison with manual robot programming.

Enhanced photomultiplication of organic photodetectors via phosphorescent material incorporation

The key performance parameters of PM-OPDs were markedly enhanced by introducing the phosphorescent material FIrpic in the active layer, and the corresponding device exhibited high-quality imaging by utilizing imaging systems without current preamplifiers.

Performance Analysis of Spatially Correlated Cylindrical Antenna Array for 3D Massive MIMO

The spectral efficiency of three-dimensional (3D) massive MIMO is impaired due to the spatial correlation (SC) between closed-spaced elements of antenna arrays (AAs). This paper investigates the impacts of arbitrary Q-power variations of the Power Cosine distribution for a precise characterization of the SC. This is done by presenting mathematical expressions characterizing the SC of cylindrical antenna array (CAA) regarding Student's -t, Von Mises and Cosine distributions, for the direction of arrival (DoA) of the electromagnetic waves impinging on the receiving antenna. Unlike the Student's -t and Von Mises distribution, our outcome recorded huge mismatch between theoretical and simulation correlation coefficients for arbitrary Q-power values above ten (10) which also reduced the downlink channel capacity. The practical relevance is that even though higher Q-power values are the key parameters for system performance, meticulous selection of arbitrary Q-power values above ten (10) is essential to minimize errors regarding channel modelling.