scholarly journals SPECIALIZED SYMBOLIC COMPUTATION FOR STEADY STATE PROBLEMS

2013 ◽  
Vol 3 (1) ◽  
pp. 5-8
Author(s):  
Marcin Sowa
Keyword(s):  
Steady State ◽  
Programming Languages ◽  
Symbolic Computation ◽  
Optimal Algorithm ◽  
Operation Time ◽  
Mathematical Basis ◽  
Calculation Time ◽  
Implementation Scheme ◽  
Made In

An implementation of symbolic computation for steady state problems is proposed in the paper. A mathematical basis is derived in order to specify the quantities that the implementation will concern. An analysis is performed so that an optimal algorithm can be chosen in terms of the two chosen criteria – the operation time and memory needed to store symbolic expressions. The implementation scheme of the specialized class for symbolic computation is presented with the use of a general figure and by an example. The implementation is made in C++ but the presented idea can also be applied in other programming languages that share similar properties. A program using the proposed algorithm was studied for its efficiency in terms of calculation time and memory used by symbolic expressions. This is made by comparing the calculations made by the author’s program with those made by a script written in Mathematica.

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

scholarly journals ANALISA UNJUK KERJA MESIN STEMPEL FLASH MADE IN TIONGKOK MEREK FLAZ TERHADAP MESIN STEMPEL FLASH MADE IN INDONESIA MEREK MD

2020 ◽  
Vol 2 (1) ◽  
pp. 13-18
Author(s):  
Slamet Raharjo ◽  
Massus Subekti ◽  
Imam Arif Raharjo
Keyword(s):  
Grounded Theory ◽  
Electricity Consumption ◽  
Operation Time ◽  
Electrical Energy ◽  
Quality Parameter ◽  
Theory Approach ◽  
Machine Performance ◽  
Work Method ◽  
Better Than ◽  
Made In

This research aimed to find out the work method of flash stamp machine made in Tiongkok brand Flaz and flash stamp machine made in Indonesia brand MD observed from each machine performance including colour stamp quality resulted, duration in its operation, as well as power and electricity consumption. The research method adopted is qualitative method with grounded theory approach. This research conducted in Enterprise of Flash Stamp Machine made in Indonesia brand MD on Jl. Lembang Baru I West Sudimara, Ciledug, Tangerang, Banten. The result drawn from work method research of both flash stamp machine are: First,   the stamp quality resulted by flash stamp machine brand MD was better than flash stamp machine brand MD. Second, the operation time of flash stamp machine brand MD was 4 second faster, that is 3 second, while flash sta mp machine brand Flaz was 4 second. Third, the electricity power consumption of flash stamp machine brand Flaz was smaller that is 136,62 watt, while brand Flaz was 392,34 watt. Fourth, the electrical energy consumption of flash stamp machine Flaz was smaller that is 888,39 Joule, while flash stamp machine brand MD was 1709,06. The conclusion drawn from work method research of flash stamp machine made in Tiongkok brand Flaz toward flash stamp machine made in Indonesia brand MD measured from stamp output quality parameter and operation time speed, so flash stamp machine made in Indonesia brand MD is better than flash stamp machine made in Tiongkok brand Flaz. Abstrak Penelitian ini bertujuan untuk mengetahui unjuk kerja mesin stempel flash made in Tiongkok merek Flaz terhadap mesin stempel flash made in Indonesia merek MD dilihat dari performa masing-masing mesin meliputi kualitas cap stempel warna yang dihasilkannya, lama waktu pengoperasiannya, pemakaian daya serta konsumsi energi listriknya. Metode penelitian yang di gunakan adalah metode kualitatif dengan pendekatan penelitian grounded theory. Penelitian ini dilakukan di Perusahaan Pembuatan Mesin Stempel Flash made In Indonesia merek MD di Jl. Lembang Baru I Kelurahan Sudimara Barat, Ciledug, Tangerang, Banten. Hasil yang diperoleh dari penelitian unjuk kerja kedua mesin stempel flash ini adalah :  Pertama, kualitas cap stempel yang dihasilkan mesin stempel flash merek MD lebih bagus dibandingkan mesin stempel flash merek Flaz. Kedua, lama waktu operasinya 4 detik lebih cepat mesin stempel flash merek MD yaitu selama 3 detik dan 4 detik untuk mesin stempel flash merek Flaz. Ketiga, daya listrik yang dibutuhkan lebih kecil me sin stempel flash merek Flaz yaitu sebesar 136,62 watt dan 392,34 Watt untuk merek Flaz. Keempat, konsumsi energi listrik yang dibutuhkan lebih kecil mesin stempel merek Flaz yaitu 888,39 Joule dan 1709,06 Joule untuk mesin stempel flash merek MD. Kesimpulan yang diperoleh dari penelitian unjuk kerja mesin stempel flash made in Tiongkok merek Flaz terhadap mesin stempel flash made in Indonesia merek MD diukur dari parameter kualitas hasil cap dan kecepatan waktu operasi maka mesin stempel flash made in Indonesia merek MD lebih bagus dari pada mesin stempel flash made in Tiongkok merek Flaz.

scholarly journals Small-Signal Stability Analysis of Multi-Terminal DC Grids

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 130
Author(s):  
Amr Radwan
Keyword(s):  
Steady State ◽  
State Space ◽  
State Space Model ◽  
Operation Time ◽  
Power Sharing ◽  
Voltage Source ◽  
Small Signal ◽  
Small Signal Stability ◽  
Steady State Operation ◽  
The Individual

This paper presents a detailed small-signal analysis and an improved dc power sharing scheme for a six terminal dc grid. The multi-terminal DC (MTDC) system is composed of (1) two voltage-source converters (VSCs) entities operating as rectification stations; (2) two VSCs operating as inverting stations; (3) two dc/dc conversion stations; and (4) an interconnected dc networking infrastructure. The small-signal state-space sub-models of the individual entities are developed and integrated to formulate the state-space model of the entire system. Using the modal analysis, it is shown that the most critical modes are associated with the power sharing droop coefficients of the rectification stations, which are constrained by the steady-state operational requirements. Therefore, a second degree-of-freedom compensation scheme is proposed to improve the dynamic response of the MTDC system without influencing the steady-state operation. Time domain simulation results are presented to validate the analysis and show the effectiveness of the proposed techniques.

Distribution of ventilation-perfusion ratios in dogs with normal and abnormal lungs

1975 ◽  
Vol 38 (6) ◽  
pp. 1099-1109 ◽  
Author(s):  
P. D. Wagner ◽  
R. B. Laravuso ◽  
E. Goldzimmer ◽  
P. F. Naumann ◽  
J. B. West
Keyword(s):  
Pulmonary Embolism ◽  
Steady State ◽  
Gas Exchange ◽  
Clinical Investigation ◽  
Inert Gas ◽  
Blood Gas ◽  
Gas Barrier ◽  
Initial Application ◽  
Arterial Po2 ◽  
Made In

We have recently described a new method for measuring distributions of ventilation-perfusion ratios (VA/Q) based on inert gas elimination. Here we report the initial application of the method in normal dogs and in dogs with pulmonary embolism, pulmonary edema, and pneumonia. Characteristic distributions appropriate to the known effects of each lesion were observed. Comparison with traditional indices of gas exchange revealed that the arterial PO2 calculated from the distributions agreed well with measured values, as did the shunts indicated by the method and by the arterial PO2 while breathing 100 per cent 02. Also the Bohr dead space closely matched the dispersion of ventilation in realtion to VA/Q. Assumptions made in the method were critically evaluated and appear justified. These include the existence of a steady state of gas exchange, an alveolar-end-capillary diffusion equilibration, and the fact that all of the observered VA/Q inequality occurs between gas exchange units in parallel. However, theoretical analysis suggests that the method can detect failure of diffusion equilbration across the blood-gas barrier should it exist. These results suggest that the method is well-suited to clinical investigation of patients with pulmonary disease.

Steady State Eeg as a Measure of Peripheral Light Loss

1986 ◽  
Vol 30 (13) ◽  
pp. 1249-1253
Author(s):  
Richard T. Gill ◽  
Kevin M. Kenner ◽  
Andrew M. Junker
Keyword(s):  
Steady State ◽  
Stimulus Intensity ◽  
Line Of Sight ◽  
Strong Response ◽  
Experimental Conditions ◽  
Pilot Studies ◽  
Sensitive Measure ◽  
Stimulus Parameters ◽  
Light Loss ◽  
Made In

The objective of this research was to assess the feasability of using ElectroEncephaloGrams (EEG) to measure the extent of acceleration induced Peripheral Light Loss (PLL). Two pilot studies were conducted to determine if an EEG response to peripherally localized stimuli could be detected and to establish the stimulus parameters that would yield a strong response. Results revealed: (1) identifiable EEG responses to stimuli located as far as ± 60 degrees from the foveal line-of-sight; (2) higher stimulus intensity and, in particular, higher depth of modulation yielded stronger EEG responses; and (3) coherence was found to be a more sensitive measure than RMS Power or Gain. These findings were used to establish the experimental conditions that were used in a study whose objective was to estimate the minimum time necessary to detect the presence, or absence, of an EEG response to peripherally localized stimuli. Results revealed a reliabe determination for stimuli located at ± 45 degrees could be made in 20 seconds or less.

scholarly journals Innate lymphoid cells lacking surface expression of CD90 are functional

2021 ◽  
Author(s):  
J-H Schroeder ◽  
T Zabinski ◽  
J F Neves ◽  
GM Lord
Keyword(s):  
Steady State ◽  
Cell Biology ◽  
Surface Expression ◽  
Innate Lymphoid Cells ◽  
Lymphoid Cells ◽  
T Cell Biology ◽  
First Time ◽  
Made In

ABSTRACTHuge progress has been made in understanding the biology of innate lymphoid cells (ILC) by adopting several well-known concepts of T cell biology. As such flow cytometry gating strategies and markers, such as CD90, to identify ILC were discovered. Here we report that most non-NK intestinal ILC have a high expression of CD90 as expected, but surprisingly some have only a low or even no expression of this marker. CD90-negative CD127+ ILC were identified among all ILC subsets in the gut. CD90-negative cLP ILC2 were frequent at steady state. The frequency of CD90-negative CD127+ ILC was dependent on stimulatory cues in vitro and in vivo, and CD90-negative CD127+ ILC played a functional role as a source of IL-13, IFNγ and IL-17A at steady state and upon dextran sulphate sodium-elicited colitis. Hence, this study highlights for the first time that CD90 is not constitutively expressed by functional ILC in the gut.

scholarly journals Steady-state aerosol distributions in the extra-tropical, lower stratosphere and the processes that maintain them

2008 ◽  
Vol 8 (1) ◽  
pp. 3665-3692 ◽  
Author(s):  
J. C. Wilson ◽  
S.-H. Lee ◽  
J. M. Reeves ◽  
C. A. Brock ◽  
H. H. Jonsson ◽  
...  
Keyword(s):  
Steady State ◽  
Atmospheric Circulation ◽  
Northern Hemisphere ◽  
Lower Stratosphere ◽  
Size Distributions ◽  
Aerosol Properties ◽  
Made In

Abstract. Measurements of aerosol, N2O and OCS made in the Northern Hemisphere below 21 km altitude following the eruption of Pinatubo are presented and analyzed. After September 1999, the oxidation of OCS and the sedimentation of particles in the extra-tropical overworld maintain the aerosol in a steady state. This analysis empirically links precursor gas to aerosol abundance throughout this region. These processes are tracked with age-of-air which offers advantages over tracking as a function of latitude and altitude. In the extra-tropical, lowermost stratosphere, normalized volume distributions appear constant in time after the fall of 1999. Exchange with the troposphere is important in understanding aerosol evolution there. Size distributions of volcanically perturbed aerosol are included to distinguish between volcanic and non-volcanic conditions. This analysis suggests that model failures to correctly predict OCS and aerosol properties below 20 km in the Northern Hemisphere extra tropics result from inadequate descriptions of atmospheric circulation.

A New Procedure for Revision for Fracture of the Stem in Total Hip Replacement

1997 ◽  
Vol 7 (2) ◽  
pp. 70-74
Author(s):  
S. Houshian ◽  
I. Hvass ◽  
P. Riegels-Nielsen
Keyword(s):  
Fracture Surface ◽  
Total Hip Replacement ◽  
Hip Replacement ◽  
High Speed ◽  
Operation Time ◽  
Total Hip ◽  
Stem Revision ◽  
Femoral Stems ◽  
New System ◽  
Made In

A new system for antegrade removal of fractured femoral stems, the Anspach Extractor III®, is described. A conical hole is made in the fracture surface of the stem with a high speed drill. An extractor rod is then fixed into the hole with a malleable sleeve. We have used the system in eight cases of a broken Charnley stem and removed the distal hip in 6 cases without problems. 2 cases were unsuccessful and needed femoral fenestration for retrograde removal. This system is easy to use and we have found it to shorten operation time in case of broken stem revision.

scholarly journals A New Method of Priority Assignment for Real-Time Flows in the WirelessHART Network by the TDMA Protocol

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4242 ◽  
Author(s):  
Yulong Wu ◽  
Weizhe Zhang ◽  
Hui He ◽  
Yawei Liu
Keyword(s):  
Real Time ◽  
Network Flows ◽  
Heuristic Algorithms ◽  
Optimal Algorithm ◽  
Time Data ◽  
Priority Assignment ◽  
Calculation Time ◽  
Greedy Strategy ◽  
Assignment Algorithm ◽  
A Priority

WirelessHART is a wireless sensor network that is widely used in real-time demand analyses. A key challenge faced by WirelessHART is to ensure the character of real-time data transmission in the network. Identifying a priority assignment strategy that reduces the delay in flow transmission is crucial in ensuring real-time network performance and the schedulability of real-time network flows. We study the priority assignment of real-time flows in WirelessHART on the basis of the multi-channel time division multiple access (TDMA) protocol to reduce the delay and improve the ratio of scheduled. We provide three kinds of methods: (1) worst fit, (2) best fit, and (3) first fit and choose the most suitable one, namely the worst-fit method for allocating flows to each channel. More importantly, we propose two heuristic algorithms—a priority assignment algorithm based on the greedy strategy for C (WF-C) and a priority assignment algorithm based on the greedy strategy for U(WF-U)—for assigning priorities to the flows in each channel, whose time complexity is O ( m a x ( N ∗ m ∗ l o g ( m ) , ( N − m ) 2 ) ) . We then build a new simulation model to simulate the transmission of real-time flows in WirelessHART. Finally, we compare our two algorithms with WF-D and HLS algorithms in terms of the average value of the total end-to-end delay of flow sets, the ratio of schedulable flow sets, and the calculation time of the schedulability analysis. The optimal algorithm WF-C reduces the delay by up to 44.18 % and increases the schedulability ratio by up to 70.7 % , and it reduces the calculation time compared with the HLS algorithm.

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