Strategic, tactical decisions and information in Rapid Manufacturing supply chain

The efficiency and agility of its supply chain is vital to the commercial success of any product. Sharing strategic and tactical information effectively within the supply chain is often a key factor in achieving this goal. This paper proposes a framework to identify strategic, tactical decisions and information. The framework is used to conduct a sector based analysis of the Rapid Manufacturing (RM) industry. The decisions and information identified include amongst others various supply chain strategies and technical information

The whistler nozzle phenomenon

The whistler nozzle is a simple device which can induce jet self-excitations of controllable amplitudes and frequencies and appears highly promising for many applications involving turbulent transport, combustion and aerodynamic noise. The characteristics of this curious phenomenon are documented for different values of the controlling parameters and attempts to explain the phenomenon. It is shown that the whistler excitation results from the coupling of two independent resonance mechanisms: shear-layer tone resulting from the impingement of the pipe-exit shear layer on the collar lip, and organ-pipe resonance of the pipe-nozzle. The crucial role of the shear-layer tone in driving the organ-pipe resonance is proven by reproducing the event in pipe-ring and pipe-hole configurations in the absence of the collar. It is also shown that this phenomenon is the strongest when the self-excitation frequency matches the preferred mode of the jet

Quantum transport across van der Waals domain walls in bilayer graphene

Bilayer graphene can exhibit deformations such that the two graphene sheets are locally detached from each other resulting in a structure consisting of domains with different inter-layer coupling. Here we investigate how the presence of these domains affect the transport properties of bilayer graphene. We derive analytical expressions for the transmission probability, and the corresponding conductance, across walls separating different inter-layer coupling domain. We find that the transmission can exhibit a valley-dependent layer asymmetry and that the domain walls have a considerable effect on the chiral tunnelling properties of the charge carriers. We show that transport measurements allow one to obtain the strength with which the two layers are coupled. We performed numerical calculations for systems with two domain walls and find that the availability of multiple transport channels in bilayer graphene modifies significantly the conductance dependence on inter-layer potential asymmetry.Comment: 20 pages, 24 Figure

Human-centric light sensing and estimation from RGBD images: the invisible light switch

Lighting design in indoor environments is of primary importance for at least two reasons: 1) people should perceive an adequate light; 2) an effective lighting design means consistent energy saving. We present the Invisible Light Switch (ILS) to address both aspects. ILS dynamically adjusts the room illumination level to save energy while maintaining constant the light level perception of the users. So the energy saving is invisible to them. Our proposed ILS leverages a radiosity model to estimate the light level which is perceived by a person within an indoor environment, taking into account the person position and her/his viewing frustum (head pose). ILS may therefore dim those luminaires, which are not seen by the user, resulting in an effective energy saving, especially in large open offices (where light may otherwise be ON everywhere for a single person). To quantify the system performance, we have collected a new dataset where people wear luxmeter devices while working in office rooms. The luxmeters measure the amount of light (in Lux) reaching the people gaze, which we consider a proxy to their illumination level perception. Our initial results are promising: in a room with 8 LED luminaires, the energy consumption in a day may be reduced from 18585 to 6206 watts with ILS (currently needing 1560 watts for operations). While doing so, the drop in perceived lighting decreases by just 200 lux, a value considered negligible when the original illumination level is above 1200 lux, as is normally the case in offices

Performance of socially responsible investment funds in China: A comparison with traditional funds

This paper empirically examines and compares social responsibility investment funds to traditional funds, and explores the performance of the existing social responsibility investment funds in China. Based on 64 social responsibility investment funds (SRI Funds) and 64 traditional funds, this paper extracts the data of the sample fund from the fourth quarter of 2016 to the fourth quarter of 2019 as sample data to conduct a comparative analysis of the difference between the SRI fund and the traditional fund in terms of return and risk, and to then empirically study the performance of the funds. The results show that the difference between the return of China’s socially responsible investment funds and the traditional funds is insignificant, and the risk of socially responsible investment funds is significantly lower than that of traditional funds. The regression analysis is also carried out on a model of social responsibility as a factor affecting the performance of the funds. Subsequently, the results show that social responsibility has a significant positive impact on the fund’s return in the Chinese market

Prediction of Flow Duration Curve for Seasonal Rivers in Iraq

This paper presents a new method to estimate the flow duration curves [FDCs] for ungauged river basins whose natural and meterological characteristics are known. This study highlights the modeling of the lower three-quarters of the section of the flow duration curves [FDCs]. Eight sub-catchments were used to develop and evaluate the proposed flow duration model in the north of Iraq. The logarithmic type function has been found appropriate for the lower three-quarters of the section of [FDCs] for all river sub-catchments located in the study area. Parameter values of the logarithmic function model were calculated using topographic, hydrological and climatic characteristics of the basins under study by two regional regression models: first CA-MAP (catchment area-mean annual precipitation) model and second MAF-PE (mean annual flowpotential evapotranspiration) model. Generally, it is found that both models used were predicting a good estimate at the end of the flow duration curve (low-flows). In most cases, the statistics and graphical results showed that the agreement between observed and estimated FDCs is very good by using MAF-PE model as compared to CA-MAP model

Design and Development of Hand and Foot Contamination Monitor

A hand and foot contamination monitor is a health physics instrument to provide detection and measurement of beta-gamma contamination on the palm of each hand and on the bottom surface of both feet/shoes. There are four channels of detection for two hands and two feet. Four G-M detectors have been used in a single unit to cover the whole area of hand and feet. A regulated high voltage DC power supply (900 V) has been designed using the PIC12F675 microcontroller to operate the pancake Geiger-Müller detectors. The reading is displayed on a linearly scaled 0-100 Bq/cm2 analog panel meter. The monitor detects beta–gamma radiation emitted by radioactive materials, and if the detected value exceeds a preset level, the monitor sounds an alarm and displays a reading in the respective panel meter. Indicator lamps are used to show the status of contamination. The performance of the system has been tested by using pulse generator and by flat surface radioactive calibration sources. Electronic linearity, detection efficiency, response to the contamination, calibration factor and percentage of error has been measured. Test results were satisfactory and the present system can be used instead of similar imported instruments. Received: 21 May 2014; Revised: 21 August 2014; Accepted: 22 August 201

Teaching Primary Science with Computer Simulation – an Intervention Study in State of Kuwait

This thesis describes an investigation into use of interactive computer simulations software in primary science education. The research questions are what effects teaching with interactive computer simulations have on students’ achievement, their conceptual change in particular science topics and on their attitudes. The question was investigated in an intervention study that tested use of simulations in two different pedagogical environments. The first environment used simulations in a computer laboratory, with students using blended learning (combining computer-based learning with non-computer learning). In this environment students worked independently on the computer. The second environment is class teaching. In this environment, the simulation was used on one computer, controlled by the teacher, in front of the class. The study also investigated ease of use and looked into practical consideration of computer-based teaching expressed by students and teachers. Three science topics were studied. The novelty of the research is using computer simulations in an Arabic nation, which has widespread use of traditional didactic-oriented pedagogy. Recent educational reforms have made demand for more student-oriented teaching, with use of practical experiments in primary science. This major change is difficult to implement for practical reasons, and the study therefore asks if computer simulations may work as an alternative approach to reach the same aims. The theoretical frameworks for the study are constructivism, conceptual change and cognitive multi-media theory. The first of these looks at the role of the student in learning, the second takes into consideration that students enter school with intuitive knowledge about natural phenomena and the last explains learning with use of computers. The theoretical frameworks were used to guide development of the simulation software and the intervention. The participants were 365 students in year five (10-11 year olds) and eight science teachers in Kuwait, located at eight different primary schools. All schools were single sex, with half the schools of each gender. All teachers were female. The study used a quasi-experimental design and separated the students into two experimental groups and two control groups. The first experimental group, which used simulations in computer labs, had 91 students in four primary schools (two boys’ and two girls’ schools). A matching control group with the same number of students was established in the same schools. The other experiment group had 92 students using simulations in the classroom. This group was also matched with an appropriate control group. The eight teachers taught both experimental and control group students. The control groups used traditional teaching. The experiment was carried out in the academic year 2010-2011. The study measured effects of the interventions with pre- and post achievement tests and attitude questionnaires. Students in the experimental groups also answered a usability questionnaire. A sub-sample of students and all teachers were interviewed for triangulation of the questionnaire data and to learn more about experiences with using the simulation software. The results of the study revealed no statistically significant difference (at the 0.05 level) in achievement or attitude between the students who used computer simulations in the computer laboratory. Students, however, who were taught with simulations in the classroom scored significantly higher on both achievement tests and attitude questionnaires. This benefit applied also to conceptual change of specific topics. In general, the interviews revealed that science teachers and students were satisfied with the simulation program used in science teaching and learning. However, the interviews indicated that there were some problems related to infrastructure and use of computers in the teaching that might have influenced the outcome of the study. These problems are relevant also to use of computer simulations in science teaching more widely