A control chart procedure for student grade monitoring

This article reports an application of the control chart procedure for monitoring award of grades to students by the teaching staff in a large university. The chart procedure signals the presence of special cause variations if any in the award of grades. Implementation of the grade monitoring procedure saved considerable time and effort while ensuring that the reported special cause situations are justified. The mathematical derivations for the new control chart scheme are also presented

MATHEMATICAL MODEL OF DIESEL ENGINE CHARACTERISTICS FOR DETERMINING THE PERFORMANCE OF TRACTION DYNAMICS OF WHEEL-TYPE TRACTOR

Wheel-type tractors carry out a range of processing operations, with the exception of early spring work, when caterpillar tractors are used to reduce the compaction effect on the soil. Therefore, to plan the costs and reserves associated with fuel consumption, it is necessary to have an estimate of the fuel economy of the tractor in basic agricultural operations. An objective assessment of fuel consumption requires a mathematical model that describes the fuel characteristics of the engine, taking into account the speed and load torque in a wide range of variation. Verification of the model is possible only with experimental data. Since the efficiency and fuel economy of a tractor depends not only on engine performance, but also on the perfection of the transmission, the running system and the rational choice of speed, it is necessary to take into account the time-varying nature of the tractor’s traction load. The complex of agricultural operations can be divided into characteristic cycles of load change over time. This principle is the basis of PowerMix test cycles, which are conducted on a concrete track to ensure repeatability of the experiment. The use of the variable load on the tractor in the PowerMix tests is positive, but in actual field tests the results may differ due to the instability of the soil properties. On the other hand, PowerMix field cycles can be taken as standard test loads in the simulation of tractor traction tests on the groun

Vindication

Part 3 of a triptych of performances. The previous 2 were Variation and Verification. This performance was 4 hours taking place in the foyer space at Back Hill, Central Saint Martinsn on thursday 7th May

Exploring the Sources of Enterprise Agility in Software Organizations

Organizations involved in the design, development and sustainment of software systems have to manage the tension between creating new products and services, while at the same time maintaining their existing portfolio. This paper explores the sources of enterprise agility in software firms, wherein agility is defined as the ability of the organization to sense changes in its environment (both internal and external), and effectively respond to these changes. Using engaged scholarship as the overarching paradigm, we report on the findings of a process study that uses semi-structured interviews, observation, and archival firm & project information for data gathering, and grounded theory methods and comparative case analysis for data analysis and theory generation. The analysis highlights the importance of the four organizational enablers of: stakeholder alignment, employee empowerment, group & organizational learning, and governance mechanisms, as necessary but not sufficient precursors to obtaining enterprise agility. Furthermore, we provide illustrative case examples of the three mechanisms: Continuous Improvement, Creating Systems of Innovation, and Leveraging Globally available Capabilities, that software organizations use to gain enterprise agility

Broadband power amplifier tube: Klystron tube 5K70SK-WBT and step tuner VA-1470S

The design concept, the fabrication, and the acceptance testing of a wide band Klystron tube and remotely controlled step tuner for channel selection are discussed. The equipment was developed for the modification of an existing 20 KW Power Amplifier System which was provided to the contractor as GFE. The replacement Klystron covers a total frequency range of 2025 to 2120 MHz and is tuneable to six (6) each channel with a band width of 22 MHz or greater per channel. A 5 MHz overlap is provided between channels. Channels are selected at the control panel located in the front of the Klystron magnet or from one of three remote control stations connected in parallel with the step tuner. Included in this final report are the results of acceptance tests conducted at the vendor's plant and of the integrated system tests

Low-cost, high-precision DAC design based on ordered element matching and verification against undesired operating points for analog circuits

Over the past 50 years, the integrated circuit (IC) industry has grown rapidly, following the famous ``Moore\u27s law. The process feature size keeps shrinking, whereby the performance of digital circuits is constantly enhanced and their cost constantly decreases. However, with the system integration and the development of system on chip (SoC), nearly all of today\u27s ICs contain analog/mixed-Signal circuits. Although a mixed-signal SoC is primarily digital, the analog circuit design and verification consume most of the resources, and the dominant source of IC breakdowns is attributable to the analog circuits. One important reason for the high cost and risk of breakdowns of analog circuits is that the technology advancement does not benefit many analog and mixed-signal circuits, and in fact imposes higher requirements on their performance. With process scaling, many important parameters of integrated circuit components degrade, which cause a drop in many key aspects of performance of analog circuits. Many analog circuits rely on matched circuit components (transistors, resistors, or capacitors) to achieve the required linearity performance; examples are amplifiers, digital-to-analog converters (DACs), etc. However, shrinking of the feature sizes increases the circuit components mismatch, thereby making it more difficult to maintain circuit accuracy. Therefore, to reduce the cost of analog circuit design, designers should propose new structures whose key performance can be improved by the technology scaling. In this dissertation, we propose a low-cost, high-precision DAC structure based on ordered element matching (OEM) theory. High matching accuracy can be achieved by applying OEM calibration to the resistors in unary weighted segments and calibrating the gain error between different segments by calibration DAC (CalDAC). As a design example to verify the proposed structure, a high-precision DAC is designed in a 130 nm Global Foundry (GF) CMOS process. The 130 nm GF process features high-density digital circuits and is a typical process which is constantly enhanced by the scaling of device dimensions and voltage supply; implementation of a high-precision DAC in such process is important to decreasing the costs of high-precision DAC designs. As a result, our proposed DAC structure is demonstrated to be able to significantly lower the cost of high-precision DAC design. Another reason for the high cost and risk of breakdowns of analog circuits arises from the complexity of analog circuit working states. Most digital circuits serve as logic functions, so that digital transistors work in only two states, either low or high. In contrast, analog circuits have much more complicated functions; they may work in multiple operating points, since various feedback approaches are applied in analog circuits to enhance their performance. Circuits with undetected operating points can be devastating, particularly when they are employed in critical applications such as automotive, health care, and military products. However, since the existing circuit simulators provide only a single operating point, recognizing the existence of undesired operating points depends largely on the experiences of designers. In some circuits, even the most experienced designers may not be aware that a circuit they designed has undesired operating points, which often go undetected in the standard simulations in the design process. To identify undesired operating points in an analog circuit and reduce its risk of breakdowns, a systematic verification method against undesired operating points in analog circuits is proposed in this dissertation. Unlike traditional methods of finding all operating points, this method targets only searches for voltage intervals containing undesired operating points. To achieve this, our method first converts the circuit into a corresponding graph and locates the break point to break all the positive feedback loops (PFLs). For one dimensional verification, divide and contraction algorithms could be applied to identify undesired operating points. Two dimensional vector field methods are used to solve the two dimensional verifications. Based on the proposed verification methods against undesired operating points, an EDA tool called ``ITV is developed to identify undesired operating points in analog and mixed-signal circuits. Simulation results show ITV to be effective and efficient in identifying undesired operating points in a class of commonly used benchmark circuits that includes bias generators, voltage references, temperature sensors, and op-amp circuits

Mathematical model of diesel engine characteristics for determining the performance of traction dynamics of wheel-type tractor

Wheel-type tractors carry out a range of processing operations, with the exception of early spring work, when caterpillar tractors are used to reduce the compaction effect on the soil. Therefore, to plan the costs and reserves associated with fuel consumption, it is necessary to have an estimate of the fuel economy of the tractor in basic agricultural operations. An objective assessment of fuel consumption requires a mathematical model that describes the fuel characteristics of the engine, taking into account the speed and load torque in a wide range of variation. Verification of the model is possible only with experimental data. Since the efficiency and fuel economy of a tractor depends not only on engine performance, but also on the perfection of the transmission, the running system and the rational choice of speed, it is necessary to take into account the time-varying nature of the tractor’s traction load. The complex of agricultural operations can be divided into characteristic cycles of load change over time. This principle is the basis of PowerMix test cycles, which are conducted on a concrete track to ensure repeatability of the experiment. The use of the variable load on the tractor in the PowerMix tests is positive, but in actual field tests the results may differ due to the instability of the soil properties. On the other hand, PowerMix field cycles can be taken as standard test loads in the simulation of tractor traction tests on the ground

LEVANTAMENTO DA DISPERSÃO E VARIABILIDADE GENÉTICA DE Tectococcus ovatus (HETEROPTERA: ERIOCOCCIDAE) NAS REGIÕES DE OCORRÊNCIA NATURAL DE Psidium cattleianum (MYRTACEAE)

 A espécie Psidium cattleianum é considerada uma das maiores ameaças ao ecossistema e à biodiversidade nas ilhas do Havaí. Buscando controlar sua disseminação, adotaram-se técnicas de controle biológico. Dentre as várias espécies estudadas como agente de controle, Tectococcus ovatus (Heteroptera: Eriococcidae) apresentou o maior nível de especificidade. Este trabalho teve como objetivo verificar a existência de variabilidade genética entre e dentro das diferentes populações de Tectococcus ovatus amostradas, utilizando a técnica de PCR-RAPD. As análises foram realizadas a partir de fêmeas coletadas nos estados do Rio de Janeiro, Paraná, Santa Catarina e Rio Grande do Sul. Dos oito iniciadores de PCR-RAPD testados, quatro foram utilizados nas análises, revelando marcadores monomórficos e polimórficos com uma freqüência variável, tanto para os indivíduos de uma mesma localidade quanto para os indivíduos de localidades diferentes. Através da análise de agrupamento de caracterização molecular, foi possível verificar a formação de dois grupos distintos, A e B, apresentando uma variabilidade genética de 44%. Os resultados obtidos através da análise dos marcadores RAPD foram úteis na verificação de variação e forneceram informações sobre os níveis de variabilidade e similaridade entre e dentro das diferentes populações de Tectococcus ovatus.Palavras-chave:  Controle biológico; variabilidade genética; PCR-RAPD. AbstractSurvey of dispersal and genetic variability of Tectococcus ovatus (Heteroptera: Eriococcidae) in the regions of natural occurence of Psidium cattleianum (Myrtaceae). The species Psidium cattleianum is considered one of the greatest threats to the ecosystem and biodiversity of the islands from Hawaii. Seeking to control its dissemination, techniques of biological control were used. Among the various species studied, as a biological control agent, Tectococcus ovatus showed a higher level of specificity. This work had as its aim to verify the existence of genetic variability among and inside different populations of Tectococcus ovatus sampled, using the technique of PCR-RAPD. The analyses were made from females collected in the states of Rio de Janeiro, Paraná, Santa Catarina and Rio Grande do Sul. From the eight initiators of PCR-RAPD tested, four were used in the analyses, revealing monomorphic and polimorphic markers with a variable frequency, to the individuals of one place as well as to the individuals of different places. Through the analysis of the grouping of molecular characterization it was possible to verify a formation of two distinctive groups A and B, presenting a genetic variability of 44%. The results obtained through the analysis of RAPD markers were useful to variation verification and provided safe information about the levels of variability and similarity amongst and inside the different populations of Tectococcus ovatus.Keywords:  Biological control; genetic variability; PCR-RAPD.AbstractThe species Psidium cattleianum is considered one of the greatest threats to the ecosystem and biodiversity of the islands from Hawaii. Seeking to control its dissemination, techniques of biological control were used. Among the various species studied, as a biological control agent, Tectococcus ovatus showed a higher level of specificity. This work had as its aim to verify the existence of genetic variability among and inside different populations of Tectococcus ovatus sampled, using the technique of PCR-RAPD. The analyses were made from females collected in the states of Rio de Janeiro, Paraná, Santa Catarina and Rio Grande do Sul. From the eight initiators of PCR-RAPD tested, four were used in the analyses, revealing monomorphic and polimorphic markers with a variable frequency, to the individuals of one place as well as to the individuals of different places. Through the analysis of the grouping of molecular characterization it was possible to verify a formation of two distinctive groups A and B, presenting a genetic variability of 44%. The results obtained through the analysis of RAPD markers were useful to variation verification and provided safe information about the levels of variability and similarity amongst and inside the different populations of Tectococcus ovatus.Keywords:  Biological control; genetic variability; PCR-RAPD

(E‑) Valuative Metrics as a Contested Field: A Comparative Analysis of the Altmetrics‑ and the Leiden Manifesto

This article comparatively analyzes two manifestos in the field of quantitative science evaluation, the Altmetrics Manifesto (AM) and the Leiden Manifesto (LM). It employs perspectives from the Sociology of (E-) Valuation to make sense of highly visible critiques that organize the current discourse. Four motifs can be reconstructed from the manifestos’ valuation strategies. The AM criticizes the confinedness of established evaluation practices and pledges for an expansion of quantitative research evaluation. The LM denounces the proliferation of ill-applied research metrics and calls for an enclosure of metric research assessment. It can be shown that these motifs are organized diametrically: The two manifestos represent opposed positions in a critical discourse on (e-) valuative metrics. They manifest quantitative science evaluation as a contested field.Peer Reviewe