Investigation on fatigue damage equivalence probability for the structure with similar fatigue hazardous detail parts

Fatigue damage of a whole structure with multiple similar fatigue hazardous detail parts is unclear. This paper focuses on the concept of quantified fatigue damage for the structure with similar fatigue hazardous detail parts by using the probability method and fatigue failure probability of the severe load spectrum. The probability criterion and calculation method of equivalent damage with different load spectra were proposed. The fatigue life probability distribution of the severe load spectrum was analyzed, and the acceleration ratio was defined by the similar details number of fatigue cracking in combination with the fatigue failure probability characteristics of the severe load spectrum. The results show that there is good agreement between the similar details number range of fatigue cracking in two load spectra, which means they are considered to be equivalent. The ratio of the sum of two similar details number ranges is used as acceleration ratio to evaluate the severe load spectrum. The application of this study in the statistical sense of engineering structure fatigue failure is more convincing.

Competitiveness and export development strategy for Indonesia's creative economy sector in the ASEAN market

The main objectives of this study are (1) to analyze the competitiveness of Indonesian exports in the ASEAN market (2) to formulate a strategy that will be able to support the export competitiveness of Indonesia's creative economy. Revealed Comparative Advantage, Acceleration Ratio, Export Competitiveness Index, and SWOT analysis (to determine a creative economy export development strategy using quantitative) were used as analysis tools. This study focused on examining the subsectors of architecture, movies, animation and video, craft, culinary, music, fashion, publishing, and art. Based on the results, we conclude that all subsectors have export competitiveness in the ASEAN market. Among them, craft and culinary appear as subsectors with strong competitiveness and meet all the analysis criteria. The results also show that SO strategy (growth) could be chosen to develop the creative economy.

Design of experiments for light-speed invariance to moving observers

The principle of the constancy of the velocity of light, which stated that the light velocity is invariant to the motion of the emitter, was well established and directly proven by many experiments. Interestingly, the further assumption that the light velocity is also independent of the motion of the observer was, arguably, never conclusively proven by any experiment for a century. This paper tried to address some perceived technical difficulties in such experiments and proposed two experiments to test this assumption. One is to directly measure the light speed as to moving sensors, with the setup designed in such a way that the concerns of time synchronization and dilation can be avoided. Another experiment is to test the isotropy of the light speed to a high-speed particle by measuring the momentum to acceleration ratio. The experiment results, if positive, will provide direct proof of the assumption. Otherwise, it may imply a need for further investigation. Since the light speed invariance to moving observers is a key assumption of some fundamental physical theory, either way, the experiments will have significant importance.

Design of Experiments for Light Speed Invariance to Moving Observers

The principle of the constancy of the velocity of light, which stated that the light velocity is invariant to the motion of the emitter, was well established and directly proven by experiments. Interestingly, the further assumption that the light velocity is independent of the motion of the observer was, arguably, never directly proven by any experiment for a century. This paper proposed the design of two experiments to directly test this assumption, which tried to address some perceived technical difficulty in such experiments. One is to directly measure the light speed as to moving sensors. The experiment setup is designed in such a way that the concerns of time synchronization and dilation can be avoided. Another experiment is to test the isotropy of the light speed to a moving particle in the electromagnetic accelerator by measuring the momentum to acceleration ratio. The experiment result, if positive, will provide direct and solid proof of the assumption. Otherwise, it may imply a need for further investigation. Since the light speed invariance to moving observers is a key assumption of some fundamental physical theory, either way, the experiments will have significant meanings.

Design of experiments for light speed invariance to moving observers

The principle of the constancy of the velocity of light, which stated that the light velocity is invariant to the motion of the emitter, was well established and experimentally proven. Interestingly, the further assumption that the light velocity is independent of the motion of the observer was never directly proven by any experiment for a century. This paper proposed the design of two experiments to directly test this assumption. One is to directly measure the light speed as to moving sensors. The experiment setup is designed in such a way that the concerns of time synchronization and dilation can be avoided. Another experiment is to test the isotropy of the light speed to a moving particle in the electromagnetic accelerator by measuring the momentum to acceleration ratio. Since the light speed invariance to observers is a key assumption, the experiment result, if positive, will cover a long-time gap. Otherwise, it may imply a need for further investigation. Either way, the experiments will have significant meanings in physical theory.

Multi-granularity pruning for deep residual networks

Network pruning has been widely used to reduce the high computational cost of deep convolutional neural networks(CNNs). The dominant pruning methods, channel pruning, removes filters in layers based on their importance or sparsity training. But these methods often give limited acceleration ratio and encounter difficulties when pruning CNNs with skip connections. Block pruning methods take a sequence of consecutive layers (e.g., Conv-BN-ReLu) as a block and remove entire block each time. However, previous methods usually introduce new parameters to help pruning and lead additional parameters and extra computations. This work proposes a novel multi-granularity pruning approach that combines block pruning with channel pruning (BPCP). The block pruning (BP) module remove blocks by directly searches the redundant blocks with gradient descent and leaves no extra parameters in final models, which is friendly to hardware optimization. The channel pruning (CP) module remove redundant channels based on importance criteria and handles CNNs with skip connections properly, which further improves the overall compression ratio. As a result, for CIFAR10, BPCP reduces the number of parameters and MACs of a ResNet56 model up to 78.9% and 80.3% respectively with <3% accuracy drop. In terms of speed, it gives a 3.17 acceleration ratio. Our code has been made available at https://github.com/Pokemon-Huang/BPCP.

Tensile and Fatigue Failure of 17-4 PH Martensitic Stainless Steels in Presence of Hydrogen Depending on Frequency and Heat Treatment

Slow-strain-rate tensile (SSRT) and fatigue-life tests were carried out on 17-4PH martensitic stainless steel with an ultimate tensile strength (UTS) of ∼ 1 GPa. The specimens were precharged by exposure to hydrogen gas at pressures of 35 MPa or 100 MPa at 270°C for 200 h. The SSRT tests used smooth axisymmetric specimens made of two grades of 17-4PH (H1150 and H900) differing by the UTS due to their thermal history. No degradation of the UTS was observed for both H1150 and H900 grades. However, the relative reduction in area (RRA) was 0.31 for H1150 or 0.11 for H900, translating a difference in their hydrogen sensitivity. Both grades presented different fracture-surface morphologies: a mixture of quasi-cleavage (QC) and intergranular (IG) facets for H1150 and cleavage (C) facets for H900. Circumferentially-notched axisymmetric specimens made of H1150 were used for the fatigue-life tests in the [10−3 Hz;10 Hz] frequency range. Our previous study on low-alloy steels with UTS of around 950 MPa demonstrates that the fatigue life of a circumferentially-notched specimen with a sharp notch can be successfully predicted from the fatigue crack growth (FCG) property following the Paris law. This study used the same specimen geometry and a BCC steel with a similar UTS value; hence, the FCG behavior was investigated from the fatigue-life test of the notched specimen. As a result, the degradation of fatigue lives attributed to the FCG acceleration was observed in presence of hydrogen. A FCG acceleration ratio bounded to 30 was observed in the high-cycle regime, accompanied by QC facets. A FCG acceleration ratio bounded to ∼100 was observed in the low-cycle regime, accompanied by QC and IG facets. A FCG model accounting for the interaction of elementary mechanisms was proposed and succeeded in predicting the FCG acceleration ratio observed on H1150. This model was also successfully applied to a low-alloy steel with a comparable UTS (1002 MPa) tested in gaseous hydrogen.

Analisis Daya Saing Kopi Indonesia di Pasar Internasional

Based on coffee export data 2008-2017, the index value of Indonesia's coffee trade specialization is positive (0-1). The average value of ISPs of Indonesian coffee for 10 years is 0.91, meaning that Indonesia tends to be a coffee exporter country. Indonesian coffee has competitiveness in the international market with an acceleration ratio value between 10.66 in 2012 to 53.76 in 2008. The always positive acceleration ratio (AR) value shows that Indonesian coffee is able to win the world coffee market. Indonesian coffee also has a comparative advantage with the value of Revealed Comparative Advantages (RCA) which is always positive. The highest RCA value of Indonesian coffee occurred in 2008 at 5.26 and the lowest RCA value in 2011 was 2.60, while the average RCA value of Indonesia was 3.93.

Assessment of Head Impacts and Muscle Activity in Soccer Using a T3 Inertial Sensor and a Portable Electromyography (EMG) System: A Preliminary Study

Heading the ball is an important skill in soccer. Head impacts are of concern because of the potential adverse health effects. Many elite players now wear GPS (that include inertial monitoring units) on the upper spine for location tracking and workload measurement. By measuring the maximum acceleration of the head and the upper spine, we calculated the acceleration ratio as an attenuation index for participants (n = 8) of different skill levels during a front heading activity. This would allow for in-field estimates of head impacts to be made and concussive events detected. For novice participants, the ratio was as high as 8.3 (mean value 5.0 ± 1.8), whereas, for experienced players, the mean ratio was 3.2 ± 1.5. Elite players stiffen the neck muscles to increase the ball velocity and so the torso acts as a support structure. Electromyography (EMG) signals that were recorded from the neck and shoulder before and after a training intervention showed a major increase in mean average muscle activity (146%, p = 3.39 × 10−6). This was accompanied by a major decrease in acceleration ratio (34.41%, p = 0.008). The average head-ball impact velocity was 1.95 ± 0.53 m/s determined while using optical motion capture. For this low velocity, the impact force was 102 ± 19 N, 13% of the published concussive force. The voluntary action of neck muscles decreases isolated head movements during heading. Coaches and trainers may use this evidence in their development of junior players.