Journal articles: 'Two and three-shift operation'

1

Huang, Yu Ping, Yue Zhong, Zai Ping Zheng, Ying Xu, and Hong Xing Wu. "Analysis of Two-Phase Operation Mechanism of Three-Phase Motor Based on Capacitor Phase Shift Method." Applied Mechanics and Materials 556-562 (May 2014): 2058–62. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.2058.

Full text

Abstract:

In the absence of a three-phase power source, single-phase operation of three-phase induction motor used single-phase power source had a certain practical significance. In this paper, utilized symmetrical component method analysed the asymmetric circuit system of motor, will be voltage and current of the three-phase stator windings decomposed into positive, negative and zero sequence three groups symmetrical components. The theory is analyzed and the formula is deduced of capacitor phase shift method, solved the problem of starting torque, proposed to add starting capacitors and deduced the optimal value of starting capacitor. Finally, the single-phase operation of three-phase induction motor is simulated and verified by simulation software.

APA, Harvard, Vancouver, ISO, and other styles

2

Li, Xinwang, Li Li, Huayong Lv, and Tianqiang Guan. "The shift step optimization of belt conveyor in self-advancing semi-continuous mining technology based on SIMIO." World Journal of Engineering 14, no. 4 (2017): 324–28. http://dx.doi.org/10.1108/wje-10-2016-0116.

Full text

Abstract:

Purpose This paper aims to develop a computer simulation processing method to simulate the mining operation of self-advancing semi-continuous mining technology and optimize the shift step of belt conveyor by using simulation modeling framework based on intelligent objects (SIMIO). The method would effectively solve the challenge of field testing such large-scale equipment. Design/methodology/approach The four operational modes of self-advancing semi-continuous mining technology at single bench had been illustrated. The operational system of this technology was analyzed and broken down to single units. By analyzing the time constitution of one operation cycle, the theoretical optimization model of shift step can be established and the optimization criteria is the time utilization ratio being maximum. Once the simulation flow was determined, a three-dimensional (3D) computer simulation model of this mining technology was developed by adapting the SIMIO simulating software to the theoretical model. The models were run to investigate the outputs from different operational modes using geological and mining data from East open-pit mine. Findings The result of these simulations showed that the four-mining-width one-shift (FMWOS) is at maximum production capacity during all operation modes. If transfer equipment is necessary, then this mode can adapt, but system will become more complex. There are minor differences between two-mining-width one-shift and three-mining-width one-shift. If transfer equipment is not necessary, then the two-mining-width one-shift can adapt during actual production. Originality/value The simulation results show that the proposed method can achieve the optimal shift step of a belt conveyor and effectively reduce the time loss caused by the coordination of multiple pieces of equipment while simultaneously improving operational efficiency.

APA, Harvard, Vancouver, ISO, and other styles

3

Odden, David. "Tone shift and spread in Taita I." Studies in African Linguistics 30, no. 1 (2001): 76–99. http://dx.doi.org/10.32473/sal.v30i1.107363.

Full text

Abstract:

Numerous Bantu languages have processes of rightward shift or spread of H tone. Sometimes the process is quite simple: every H shifts once to the right (as in Cijita) or spreads once to the right (as in Kikerewe). The tonal system of Taita is more complex in that both shifting and spreading are found in the language. Furthermore, the extent of tone shift or spread is not just one syllable; sometimes, H tone can shift or spread by two syllables. An analysis of the tonal system of the Dembwa dialect of Taita is given here. It is argued that the facts of the language are best described in terms of two rules of rightward spreading and a third rule of tone delinking. The argument for analyzing the tone system in terms of three interacting rules rather than one unified rightward movement process resides in the fact that the environments for the three processes only overlap partially. On the theoretical front, these results support a general decomposition of the process of tone shift into tone spread interacting with tonal delinking, rather than including the operation of shift in the formal repertoire of primitive phonological operations.

APA, Harvard, Vancouver, ISO, and other styles

4

Lin, Bor-Ren. "Phase-Shift PWM Converter with Wide Voltage Operation Capability." Electronics 9, no. 1 (2019): 47. http://dx.doi.org/10.3390/electronics9010047.

Full text

Abstract:

A soft switching three-level pulse-width modulation (PWM) converter is presented for industrial electronics with wide voltage range operation, such as solar power or fuel cell applications. Phase shift PWM scheme is used on the input-side to accomplish the zero voltage turn-on on power switches and improve the converter efficiency. Three-level diode-clamp circuit topology is adopted in the presented circuit to lessen the voltage ratings on active devices for high voltage applications. Three sub-circuits with the different turns-ratio of transformers can be selected in the presented converter in order to achieve 10:1 (Vin,max = 10Vin,min) wide input voltage operation when compared to the conventional multilevel converter. The proposed circuit is a single-stage converter instead of two-stage converter to realize wide voltage operation. Therefore, the presented converter has less component counts. Finally, the design procedure and experiments with a 300W laboratory circuit are presented and discussed to confirm the circuit analysis and converter performance.

APA, Harvard, Vancouver, ISO, and other styles

5

Pearson, Michael. "Issues associated with two-shift operation of combined cycle generating plant." Materials at High Temperatures 18, no. 4 (2001): 211–14. http://dx.doi.org/10.1179/mht.2001.022.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Takahashi, Daiko. "Determiner Raising and Scope Shift." Linguistic Inquiry 33, no. 4 (2002): 575–615. http://dx.doi.org/10.1162/002438902762731772.

Full text

Abstract:

Whether quantifier scope is regulated by movement or not has been debated for more than two decades, and this issue has become especially important in the minimalist framework. This article provides a novel argument for the existence of a scope-marking movement operation on the basis of what can be called the split-QP construction in Japanese. It is shown that the construction involves overt movement of quantificational determiners, whereby their scope is visibly marked, and that the movement operation is subject to economy so that it may apply only if it yields scope shift.

APA, Harvard, Vancouver, ISO, and other styles

7

Wu, Caicong, Zhibo Chen, Dongxu Wang, et al. "A Cloud-Based In-Field Fleet Coordination System for Multiple Operations." Energies 13, no. 4 (2020): 775. http://dx.doi.org/10.3390/en13040775.

Full text

Abstract:

In large-scale arable farming, multiple sequential operations involving multiple machines must be carried out simultaneously due to restrictions of short time windows. However, the coordination and planning of multiple sequential operations is a nontrivial task for farmers, since each operation may have its own set of operational features, e.g., operating width and turning radius. Taking the two sequential operations—hoeing cultivation and seeding—as an example, the seeder has double the width of the hoeing cultivator, and the seeder must remain idle while waiting for the hoeing cultivator to finish two rows before it can commence its seeding operation. A flow-shop working mode can coordinate multiple machines in multiple operations within a field when different operations have different implement widths. To this end, an auto-steering-based collaborative operating system for fleet management (FMCOS) was developed to realize an in-field flow-shop working mode, which is often adopted by the scaled agricultural machinery cooperatives. This paper proposes the structure and composition of the FMCOS, the method of operating strip segmenting, and a new algorithm for strip state updating between successive field operations under an optimal strategy for waiting time conditioning between sequential operations. A simulation model was developed to verify the state-updating algorithm. Then, the prototype system of FMCOS was combined with auto-steering systems on tractors, and the collaborative operating system for the server was integrated. Three field experiments of one operation, two operations, and three operations were carried out to verify the functionality and performance of FMCOS. The results of the experiment showed that the FMCOS could coordinate in-field fleet operations while improving both the job quality and the efficiency of fleet management by adopting the flow-shop working mode.

APA, Harvard, Vancouver, ISO, and other styles

8

Lin, Bor-Ren, and Ji-Wei Chang. "Analysis and Verification of a Wide Input Voltage PWM Converter with Variable Windings." Energies 13, no. 7 (2020): 1634. http://dx.doi.org/10.3390/en13071634.

Full text

Abstract:

A three-leg pulse-width modulation converter with auxiliary windings is provided and investigated to realize wide voltage operation and zero voltage switching characteristics on power switches. The presented converter has three converter legs on the input-side and two sets of winding turns on the output-side. Owing to the on/off states of the three converter legs and the two sets of secondary winding turns, the proposed converter can be operated under three different equivalent circuits to have wide input voltage operation from 30V ~ 240V (Vin,max = 8Vin,min). Compared with the multi-stage converters to realize wide input voltage operation, the proposed circuit topology has fewer circuit components and a simple control algorithm. Conventional duty cycle control with phase-shift between each converter leg is adopted to regulate load voltage and also accomplish zero voltage switching on active switches. The presented three-leg converter is tested with a laboratory circuit. Finally, experiments testify to the performance and validity of the presented converter.

APA, Harvard, Vancouver, ISO, and other styles

9

Rząsa, Mariusz, Ewelina Łukasiewicz, and Dariusz Wójtowicz. "Test of a New Low-Speed Compressed Air Engine for Energy Recovery." Energies 14, no. 4 (2021): 1179. http://dx.doi.org/10.3390/en14041179.

Full text

Abstract:

The paper presents a new design solution for the multi-cylinder compressed air engine, described in the PL 216801 patent. A characteristic feature of the engine is its double-piston operation with pistons working in pairs in opposition and a reciprocating movement in toroidal cylinders. The energy of compressed air was used more effectively in the described engine than in the solutions known so far. Comparing the engine built in accordance with the PL 216801 patent with the parameters of the MP165 and MP3000 engines, lower air consumption in relation to the power generated on the shaft is demonstrated. The described engine uses only one crankshaft and one straight complex shaft, which constitutes an innovative combination of pistons, while maintaining the same engine operation as in the case of two crankshafts operating with phase shift and working chamber shift. Such a solution results in a reduction in the harmful space occurring at the beginning of the power stroke to the value close to “zero”—the necessity to maintain the minimum distance between the pistons working in one cylinder when they are at their closest exists only to for the sake of collision-free operation—which is very desirable for the compressed engine operating with a shift of the working chamber. The mechanical efficiency of the engine has also been improved by guiding the pistons on the complex shaft, and the number of kinematic nodes was decreased by applying only three connecting rods supporting six pistons, which also makes it possible to improve the power and mass relation by approximately 25% in comparison with the currently known engines of similar power.

APA, Harvard, Vancouver, ISO, and other styles

10

LIU, DAOCHU, YIMIN LIU, XIAOFENG YIN, XIANSONG LIU, and ZHANJUN ZHANG. "GENERALIZED THREE-PARTY QUBIT OPERATION SHARING." International Journal of Quantum Information 11, no. 01 (2013): 1350011. http://dx.doi.org/10.1142/s0219749913500111.

Full text

Abstract:

Two three-party schemes of qubit operation sharing proposed by Zhang and Cheung [J. Phys. B44 (2011) 165508] are generalized by utilizing partially entangled states as quantum channels instead of maximally entangled ones. Their quantum and classical resource consumptions, necessary-operation complexities, success probabilities and efficiencies are calculated and compared with each other. Moreover, it is revealed that the success probabilities are completely determined by the shared entanglement.

APA, Harvard, Vancouver, ISO, and other styles

11

MAT DERIS, MUSTAFA, ALI MAMAT, PUA CHAI SENG, and MOHD YAZID SAMAN. "THREE DIMENSIONAL GRID STRUCTURE FOR EFFICIENT ACCESS OF REPLICATED DATA." Journal of Interconnection Networks 02, no. 03 (2001): 317–29. http://dx.doi.org/10.1142/s0219265901000415.

Full text

Abstract:

This article addresses the performance of data replication protocol in terms of data availability and communication costs. Specifically, we present a new protocol called Three Dimensional Grid Structure (TDGS) protocol, to manage data replication in distributed system. The protocol provides high availability for read and write operations with limited fault-tolerance at low communication cost. With TDGS protocol, a read operation is limited to two data copies, while a write operation is required with minimal number of copies. In comparison to other protocols. TDGS requires lower communication cost for an operation, while providing higher data availability.

APA, Harvard, Vancouver, ISO, and other styles

12

Su, Ling-Huey, and James C. Chen. "Two- and three-machine flowshop scheduling problems with optional final operation." Journal of the Chinese Institute of Industrial Engineers 28, no. 1 (2011): 55–71. http://dx.doi.org/10.1080/10170669.2010.535859.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Nau, Peter, W. Scott Melvin, Vimal K. Narula, P. Mark Bloomston, E. Christopher Ellison, and Peter Muscarella. "Laparoscopic Distal Pancreatectomy with Splenic Conservation: An Operation without Increased Morbidity." Gastroenterology Research and Practice 2009 (2009): 1–5. http://dx.doi.org/10.1155/2009/846340.

Full text

Abstract:

Objectives. The advent of minimally invasive techniques was marked by a paradigm shift towards the use of laparoscopy for benign distal pancreatic masses. Herein we describe one center's experience with laparoscopic distal pancreatectomy.Methods. A retrospective chart review was performed for all distal pancreatectomies completed laparoscopically from 1999 to 2009. Outcomes from those cases completed with a concurrent splenectomy were compared to the spleen-preserving procedures.Results. Twenty-four patients underwent laparoscopic distal pancreatectomy. Seven had spleen-conserving operations. There was no difference in the mean estimated blood loss (316 versus 285 mL, ) or operative time (179 versus 170 minutes, ). The mean tumor size was not significantly different (3.1 versus 2.2 cm, ). There was no difference in the average hospital stay (7.1 versus 7.0 days, ). Complications in the spleen-preserving group included one iatrogenic colon injury, two pancreatic fistulas, and two cases of iatrogenic diabetes. In the splenectomy group, two developed respiratory failure, three acquired iatrogenic diabetes, and two suffered pancreatic fistulas (71% versus 41% , ).Conclusions. The laparoscopic distal pancreatectomy is a safe operation with a low morbidity. Splenic conservation does not significantly increase the morbidity of the procedure.

APA, Harvard, Vancouver, ISO, and other styles

14

Kour, Darpandeep, J. P. Singh Joorel, and Neha Sharma. "Effectiveness Analysis of a Two Non-Identical Unit Standby System with Switching Device and Proviso of Rest." International Journal of Mathematical, Engineering and Management Sciences 4, no. 6 (2019): 1496–507. http://dx.doi.org/10.33889/ijmems.2019.4.6-118.

Full text

Abstract:

This paper deals with two-unit cold standby system with switching device and proviso of rest. The system consists of two non-identical units which are connected in parallel redundancy. Initially, the first unit is in operative mode and second is kept in cold standby mode. There is also a proviso for rest for the first unit after a random time from its starting operation. For operation and repair, priority is always given to first unit. A switching device is used to shift the failed unit to repair mode. If the switching device is found non-operational then priority is given to it for repair provided that system is in functional mode. The effectiveness of the proposed system has been carried out by determining various reliability characteristics of the proposed model.

APA, Harvard, Vancouver, ISO, and other styles

15

Xia, Li Xin, and Qian Zhao Lei. "Quantum Three-Qubit Phase Gate Operation by Using an Artificial Atom in a Three-Mode Cavity." Advanced Materials Research 301-303 (July 2011): 1705–9. http://dx.doi.org/10.4028/www.scientific.net/amr.301-303.1705.

Full text

Abstract:

We propose a scheme for realizing quantum three-qubit phase gate operation, in a three-mode cavity where the large detuned cavity-mode fields interact with the four-level artificial atom of an rf-SQUID in tripod-type configuration. In this scheme, the two lowest levels of the artificial atom represent the two logical states of the target qubit and two cavity-mode states are the control qubits, while the third cavity-mode field serves the gate manipulation. Since only the metastable lower levels are involved in the gate operations, the gate is insensitive to the decay rates of the artificial atom, which makes this scheme advantageous and it is important in view of decoherence.

APA, Harvard, Vancouver, ISO, and other styles

16

Chen, Jyh Wei, Yi Hong Liu, Chi Hou Chen, Yi Lin Yueh, Yun Chi Tzeng, and Jian Shiang Syu. "Design of Parallel Interleaved-Phase-Shift-PWM Inverters with Voltage Feedback Control." Applied Mechanics and Materials 229-231 (November 2012): 923–28. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.923.

Full text

Abstract:

The paper is to design and implement parallel operation of paralleled inverters with interleaved phase shift. For parallel operation, one inverter is used as master module to transmit synchronization signals to trigger the external interrupts of two microcontrollers for synchronous operation to slave module. In this paper, the design of voltage controlled loop feedback controller by proportional-integral controller is employed to have fast transient response with different load conditions. It is proposed that interleaved phase shift for parallel inverters could reduce output voltage ripple of inverter and increase the system response. The experimental results show that the proposed inverter provided a voltage output with low harmonic distortion by the proposed interleaving phase-shift parallel inverter scheme.

APA, Harvard, Vancouver, ISO, and other styles

17

Gao, Shengwei, Xi Zha, Congwei Hu, and Chenming Dong. "A New Method on Optimal Control of Triple-Phase-Shift Angle Based on MOPSO in DAB System." International Journal of Pattern Recognition and Artificial Intelligence 35, no. 09 (2021): 2158007. http://dx.doi.org/10.1142/s0218001421580076.

Full text

Abstract:

Nowadays, dual-active-bridge (DAB) DC/DC converter is widely used for its high power density and flexible operation mode. However, complex control variables and high reflux power are the main disadvantages of the system, which have become its development bottleneck. In view of this, this paper presents an in-depth analysis of the impacts of three phase-shifting degrees of freedom on the transmission power and effective values of the inductive current based on the triple-phase-shift (TPS) control strategy by deducing the relationship equations between the three degrees of freedom and the other two variables in the TPS control system. Based on the equations, the method of using the multi-objective particle swarm optimization (MOPSO) algorithm to optimize three phase shift angles is proposed, which cannot only improve the convergence speed of the optimal phase shift angle but also be ideal for solving nonlinear problems. The experimental results show that this method can improve the transmission power and reduce the effective value of inductive current.

APA, Harvard, Vancouver, ISO, and other styles

18

Xing, Pengfei, Yimin Liu, Chuanmei Xie, Xiansong Liu, and Zhanjun Zhang. "Generalized three-party sharing of operations on remote single qutrit." International Journal of Quantum Information 12, no. 03 (2014): 1450011. http://dx.doi.org/10.1142/s0219749914500117.

Full text

Abstract:

Two three-party schemes are put forward for sharing quantum operations on a remote qutrit with local operation and classical communication as well as shared entanglements. The first scheme uses a two-qutrit and three-qutrit non-maximally entangled states as quantum channels, while the second replaces the three-qutrit non-maximally entangled state with a two-qutrit. Both schemes are treated and compared from the four aspects of quantum and classical resource consumption, necessary-operation complexity, success probability and efficiency. It is found that the latter is overall more optimal than the former as far as a restricted set of operations is concerned. In addition, comparisons of both schemes with other four relevant ones are also made to show their two features, including degree generalization and channel-state generalization. Furthermore, some concrete discussions on both schemes are made to expose their important features of security, symmetry and experimental feasibility. Particularly, it is revealed that the success probabilities and intrinsic efficiencies in both schemes are completely determined by the shared entanglement.

APA, Harvard, Vancouver, ISO, and other styles

19

Zhang, Xue Hua. "Analysis of KATL Operation Simulated by TAAM." Applied Mechanics and Materials 713-715 (January 2015): 1601–4. http://dx.doi.org/10.4028/www.scientific.net/amm.713-715.1601.

Full text

Abstract:

This objective of this research is to use Jeppesen’s Total Airspace and Airport Modelersimulator of airport and airspace operations (TAAM). TAAM has the capability to create models of airspace and airports, which makes it easy to planning, analysis, and making a decision. TAAM can help researchers evaluating the impact of changes to infrastructure, operations and schedules, after mimicking the airspace or airport into model.The simulation of this paper is going to imitate the operation of KATL in two different layouts with three different flight schedules based on a valid baseline model. In this case, the study is based on VFR operating condition, and operating towards west.

APA, Harvard, Vancouver, ISO, and other styles

20

Narasimha, S., and Surender Reddy Salkuti. "An improved closed loop hybrid phase shift controller for dual active bridge converter." International Journal of Electrical and Computer Engineering (IJECE) 10, no. 2 (2020): 1169. http://dx.doi.org/10.11591/ijece.v10i2.pp1169-1178.

Full text

Abstract:

In this paper, a new closed loop hybrid phase shift control is proposed for dual active bridge (DAB) converter with variable input voltage. The extended phase shift (EPS) control is applied when load gets heavy enough and the secondary side phase shift angle decreases to zero. When this modified DAB converter operates at light loads, the triple phase shift (TPS) modulation method is applied, and the added control freedom is the secondary phase shift angle between the two-secondary side switching legs. The hybrid phase shift control (HPS) scheme is a combination of EPS and TPS modulations, and it provides a very simple closed form implementation for the primary and secondary side phase shift angles. Depending on the application by changing the phase shift angles we can achieve Buck or Boost operation. A characteristic table feedback control method has been used for closed loop operation. By using 1D look up table the proposed DAB converter provides constant 400V for any given input voltage.

APA, Harvard, Vancouver, ISO, and other styles

21

Dey, Netai Chandra, and Shibaji Dey. "Effective utilization of man shift through sustainable workload testing for underground mining machine operators. An ergonomic based man-machine interface approach." New Trends in Production Engineering 2, no. 1 (2019): 394–403. http://dx.doi.org/10.2478/ntpe-2019-0042.

Full text

Abstract:

Abstract Insight of man-machine interfaces during mining machine operations, better co-ordinance with human efficiencies and suitable workload selection in underground mining machine operation are the main viewpoints of the study. Total 12 side discharge loader (SDL) and load haul dumper (LHD) operators [N = 12] have been taken as participants of the study. The methodology is divided into two parts first part is devoted to measuring and analyzing workload response of machine operation with polar heart rate monitor. Machine operator’s heart rate ratio (HR ratio) for the whole shift is recorded and metabolic rate (MR) has been analyzed. Additionally, fatigue sustainability (FS) and degradation of muscle force (MF) are recorded for each work cycles up to exposure time period (ETP) of 360 minutes. In the second part of the methodology, based on the HR ratio recorded during the mining operation, a workload simulation study is undertaken on a treadmill at the surface following BRUCE protocol. At treadmill, based on HR ratio, workload achieved from mines along with three different workloads i.e. low, moderate and high has been tested. Differences in FS and degradation rate of MF after each workload experiment have been recorded. A result from the underground operational study shows that there is about 43.2% and 32.4% of decreasing MF for SDL and LHD operators after end of spells at mines. Additionally, a negative correlation (r = −0.99) is found between ETP and MF. The workload simulation study shows that there are significant differences between FS (p < 0.05) and MF (p < 0.05) data of mining and treadmill experiment with the same workload. In comparison to an underground operation, FS rate of low, moderate and high workload is recorded 60%, 35%, and 15% higher respectively than of mine workload. Higher FS rate may achieve due to availability of good environment. Among the tested workload only low kind of workload is found suitable for mining machinery job as degradation of MF is found significantly (p < 0.05) low and FS is found significantly (p < 0.01) high in this kind of workload. Therefore, it can be concluded that in mining machinery operation better to adopt low workload for effective utilization of man shift (EUMS) as it gives comparatively low MF degradation and better FS during continuous work.

APA, Harvard, Vancouver, ISO, and other styles

22

Ghaffarian M, R., K. Stampfer, and J. Sessions. "Comparison of three methods to determine optimal road spacing for forwarder-type logging operations." Journal of Forest Science 55, No. 9 (2009): 423–31. http://dx.doi.org/10.17221/79/2008-jfs.

Full text

Abstract:

Optimum road spacing (ORS) of forwarding operation in Styria in Southern Austria is studied in this paper. In a harvesting operation it is important to compute the ORS to minimize the total cost of harvesting and roading. The aim of this study was a comparison of different methods to study ORS. Data from 82 cycles were used to develop two models for predicting the cycle time using statistical analysis of a time study data base. The ORS was computed by three methods including Matthews’ formula (1942), Sundberg’s method (1976), and the two statistical models for predicting the cycle time. The results gave the ORS for one-way forwarding using Matthew’s formula as 1,969 m, Sund-berg’s model as 394.4 m, and the two time study models as 463 and 909 m. The analysis of forwarding data indicated that the speed was related to a distance which contributed to the difference between models and that the loading and unloading time may be related to one or several other study variables.

APA, Harvard, Vancouver, ISO, and other styles

23

Hida, Kazutoshi, Yoshinobu Iwasaki, Toshitaka Seki, and Shunsuke Yano. "Two-stage Operation for Resection of Spinal Cord Astrocytomas:Technical Case Report of Three Cases." Operative Neurosurgery 58, suppl_4 (2006): ONS—E373—ONS—E373. http://dx.doi.org/10.1227/01.neu.0000208965.41531.a3.

Full text

Abstract:

Abstract Objective and Importance: Surgery for excision of intramedullary spinal cord tumors without increasing neurological deficit is one of the more difficult operations in spinal surgery. In particular, infiltrating astrocytomas without a clear cleavage between the tumor and normal spinal cord parenchyma are difficult to remove totally without producing additional neurological impairment. In this study, we describe a two-stage resection facilitating total resection of intramedullary tumors. Clinical Presentation: Three cases of spinal cord astrocytomas were treated using a two-staged method. Technique: The first surgery included myelotomy, biopsy and duroplasty. A thin expanded polytetrafluoroethylene sheet was placed between the dorsal surface of the spinal cord and dura mater to prevent adhesions. Two or 3 weeks after surgery, a second surgery was performed to remove the now exophytic tumor. Results: Magnetic resonance imaging scans showed exophytic extrusion of the tumor in all three cases before the second operation. In each patient, we were able to carry out gross total removal of the tumors without additional neurological deficit except for transient joint position sense loss in one case. All three patients remain neurologically stable without evidence of tumor recurrence more than 3 years after surgery. Conclusion: A two-stage operation may enhance the surgeon's ability to completely resect extensive low-grade spinal cord astrocytomas and, at the same time preserve neurological function.

APA, Harvard, Vancouver, ISO, and other styles

24

Kim, Chil-Min, and Yongduk Kim. "Two-line operation of a TEA CO_2 laser with three cavity mirrors." Applied Optics 25, no. 17 (1986): 2926. http://dx.doi.org/10.1364/ao.25.002926.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Djurdjev, Mica, Robert Cep, Dejan Lukic, Aco Antic, Branislav Popovic, and Mijodrag Milosevic. "A Genetic Crow Search Algorithm for Optimization of Operation Sequencing in Process Planning." Applied Sciences 11, no. 5 (2021): 1981. http://dx.doi.org/10.3390/app11051981.

Full text

Abstract:

Computer-aided process planning represents the main link between computer-aided design and computer-aided manufacturing. One of the crucial tasks in computer-aided process planning is an operation sequencing problem. In order to find the optimal process plan, operation sequencing problem is formulated as an NP hard combinatorial problem. To solve this problem, a novel genetic crow search approach (GCSA) is proposed in this paper. The traditional CSA is improved by employing genetic strategies such as tournament selection, three-string crossover, shift and resource mutation. Moreover, adaptive crossover and mutation probability coefficients were introduced to improve local and global search abilities of the GCSA. Operation precedence graph is adopted to represent precedence relationships among features and vector representation is used to manipulate the data in the Matlab environment. A new nearest mechanism strategy is added to ensure that elements of machines, tools and tool approach direction (TAD) vectors are integer values. Repair strategy to handle precedence constraints is adopted after initialization and shift mutation steps. Minimization of total production cost is used as the optimization criterion to evaluate process plans. To verify the performance of the GCSA, two case studies with different dimensions are carried out and comparisons with traditional and some modern algorithms from the literature are discussed. The results show that the GCSA performs well for operation sequencing problem in computer-aided process planning.

APA, Harvard, Vancouver, ISO, and other styles

26

Soo, Khí-Uí, and Tim Stokes. "Algebraic properties of if-then-else and commutative three-valued tests." International Journal of Algebra and Computation 29, no. 04 (2019): 743–59. http://dx.doi.org/10.1142/s0218196719500255.

Full text

Abstract:

This paper establishes a finite axiomatization of possibly non-halting computer programs and tests, with the if-then-else operation. The model is a two-sorted algebra, with one sort being the programs and the other being the tests. The main operation on programs is composition, and 1 and 0 represent the programs skip and loop (i.e. never halts) respectively. Programs are modeled as partial functions on some state space [Formula: see text], with tests modeled as partial predicates on [Formula: see text]. The operations on the tests are the usual logical connectives ∧, ∨, [Formula: see text], [Formula: see text] and [Formula: see text]. In addition, there is the hybrid operation of if-then-else, and the test-valued operation [Formula: see text] on programs which is true when a program halts, and undefined otherwise. The halting operation [Formula: see text] implies that operations of domain [Formula: see text] and domain join ∨ may also be expressed. When tests are assumed to be possibly non-halting, the evaluation strategy of the logical connectives affects the result. Here we model parallel evaluation, as opposed to the common sequential (or short-circuit) evaluation strategy. For example, we view [Formula: see text] as false if either [Formula: see text] or [Formula: see text] is false, even if the other does not halt.

APA, Harvard, Vancouver, ISO, and other styles

27

Lin, Bor-Ren, and Yi-Hao Peng. "Analysis of a PWM Converter with Less Current Ripple, Wide Voltage Operation and Zero-Voltage Switching." Processes 9, no. 4 (2021): 580. http://dx.doi.org/10.3390/pr9040580.

Full text

Abstract:

This paper studies and implements a power converter to have less current ripple output and wide voltage input operation. A three-leg converter with different primary turns is presented on its high-voltage side to extend the input voltage range. The current doubler rectification circuit is adopted on the output side to have low current ripple capability. From the switching states of the three-leg converter, the presented circuit has two equivalent sub-circuits under different input voltage ranges (Vin = 120–270 V or 270–600 V). The general phase-shift pulse-width modulation is employed to control the presented converter so that power devices can be turned on at zero voltage in order to reduce switching loss. Compared to two-stage circuit topologies with a wide voltage input operation, the presented converter has the benefits of simple circuit structure, easy control algorithm using a general integrated circuit or digital controller, and less components. The performance of the presented circuit is confirmed and validated by an 800 W laboratory prototype.

APA, Harvard, Vancouver, ISO, and other styles

28

Nalepa, Bartlomiej, and Tomasz Halon. "Recommendations for Running a Tandem of Adsorption Chillers Connected in Series and Powered by Low-Temperature Heat from District Heating Network." Energies 14, no. 16 (2021): 4791. http://dx.doi.org/10.3390/en14164791.

Full text

Abstract:

In this paper, we investigate implications of running a cooling system of two silicagel/water adsorption chillers powered by a district heating network. The devices are connected in series, i.e., the heating water output from the primary chiller is directed to the secondary one. In consequence, the secondary device must deal with an even lower driving temperature and with temperature fluctuations caused by the primary device. We have evaluated three factors that influence the operation of those coupled devices: synchronization of their operating cycles, selection of their cycle time allocations (CTAs), and changing the heating water mass flow rate. Numerical analyses indicate that the performance of the secondary chiller drops significantly if the coupled devices that use the same CTA run asynchronously. The decrease is largest if the shift between the operating cycles is x=0.375 and x=0.875. We found that it is possible to reduce the negative influence of the asynchronous operation by implementing different CTA in each chiller. The best performance is achieved if the primary chiller uses an adsorption time to desorption time ratio f=1.0 and the secondary chiller uses f = 0.6–0.7.

APA, Harvard, Vancouver, ISO, and other styles

29

Mishima, Katsuaki, Toshio Sugahara, Yoshihide Mori, and Masayoshi Sakuda. "Palatal Configuration in Complete Bilateral Cleft Lip and Palate Infants before and after Cheiloplasty." Cleft Palate-Craniofacial Journal 34, no. 6 (1997): 475–82. http://dx.doi.org/10.1597/1545-1569_1997_034_0475_pcicbc_2.3.co_2.

Full text

Abstract:

Objective: The purpose of this study was to analyze the three-dimensional configuration of the premaxilla, vomer, and lateral segments in bilateral cleft lip and palate (BCLP) infants and to investigate the early changes in the configuration following one- and two-stage cheiloplasty. Methods: This study consisted of 10 complete BCLP infants. One-stage operations were performed in five patients according to Manchester's method at 4 months of age. Two-stage operations were done for the remaining five patients using a triangular flap according to Tennison's method, at 4 and 8 months of age. Serial plaster models before and after the cheiloplasty were measured with a computer-controlled, highly accurate, contact-type measuring apparatus. Temporal changes in the configuration and form of the premaxilla were observed using an automatic superimposition method. The inclination and deviation of the vomer were evaluated using an approximation technique to a straight line with least squares. The distance between the lateral segments and a three-dimensional coordinate of the incisal point were also measured. Results and Conclusions: The following differences in palatal configuration between the one- and two-stage cheiloplasties were observed: 1) In the two-stage group, the premaxilla shifted toward the cleft edge where the cheiloplasty was performed in both first- and second-stage operations. After the two-stage operation, the premaxilla did not shift greatly, and the premaxilla in cases 4 and 5 shifted downward and toward the cleft edge of the lateral segments where the first operation was performed. Protrusion of the premaxilla remained in the two-stage group. 2) In the one-stage group, the premaxilla in case 4 descended downward and backward without twisting or bending. The premaxillae of the other patients descended downward with twisting and bending. 3) Patients in the two-stage group had a stronger tendency toward medial collapse of the lateral segments than did those in the one-stage group.

APA, Harvard, Vancouver, ISO, and other styles

30

Butola, MS, YS Dahiya, and BK Rao. "Assessment of fatigue in personnel during sustained operations using ‘SOAP’ – Sustained Operational Assessment Profile." Indian Journal of Aerospace Medicine 64 (October 31, 2020): 2–7. http://dx.doi.org/10.25259/ijasm_38_2020.

Full text

Abstract:

Introduction: Sustained operations are the future of any advanced Air Force, which involve round the clock flying operations over a prolonged period. Such operations have the potential of disrupting normal sleep cycle and may cause fatigue among aircrew and ground duty personnel. It is well known that fatigue among crew member is a significant risk to aerospace safety. The present study was hence undertaken to quantify the subjective fatigue and its effects, among the personnel involved in a simulated exercise using Sustained Operations Assessment Profile (SOAP). Material and Methods: SOAP questionnaire, a validated tool, was used for data collection. In the first phase, 1521 personnel involved in the exercise, including aircrew as well as ground duty tradesmen completed the SOAP questionnaires twice during the simulated sustained military operation. The subjective ratings were statistically analyzed using the Wilcoxon matched paired test. The two levels of repeated measures being mean SOAP scores on day 2 and that on day 5. In the second phase, to ascertain differences in the subjective ratings of SOAP among different streams of pilots, data were recorded during another simulated sustained operation after 6 months. A total of 140 aircrew responded to the SOAP questionnaire during 6 days of sustained operations. SOAP score was acquired on day 1 and day 6 of the operations in the second phase. Results: A total of 3042 completed SOAP responses were analyzed. There was a significant increase in ratings of the three cardinal dimensions of SOAP among all personnel. The aircrew rated the subjective effects higher than maintenance or administrative support group. Among the aircrew, the fighter pilots rated significantly higher as compared to transport or helicopter aircrew. Conclusion: The study revealed significant changes in the cardinal dimensions of SOAP among the aircrew who were routinely not involved in shift work (especially fighter pilots). Scientifically designed “shift work” may be an effective strategy to mitigate effects of fatigue during sustained operations, hence, needs to be practiced as a routine by combat Air Force units.

APA, Harvard, Vancouver, ISO, and other styles

31

Ndayiragije, Juvénal. "Strengthening PF." Linguistic Inquiry 31, no. 3 (2000): 485–512. http://dx.doi.org/10.1162/002438900554415.

Full text

Abstract:

One standard assumption of the Minimalist Program is that formal, (grammatical) features are the only features that trigger the “dislocation” property of CHL. On the basis of two syntactically related properties of Fóngbé nonfinite clauses-object shift and verb doubling-I argue that pure phonological features can be overtly attracted. Three consequences follow: (a) the operation Attract F cannot be reduced to, Agree, (b) the concept of strength is inescapable, and (c) some of the effects of strength are PF-driven properties, hence not true imperfections.

APA, Harvard, Vancouver, ISO, and other styles

32

Marinache, Ramona. "Sleep, Work and Globalization: The Evening/Night Shift Employees in Call Centre in Romania." International Review of Social Research 6, no. 3 (2016): 129–36. http://dx.doi.org/10.1515/irsr-2016-0016.

Full text

Abstract:

Abstract In order to ensure synchronized operation of companies who use workforce around the world, work schedules have been divided in two or three shifts and a large number of people work in evening or night shifts. Based on interviews with 25 employees of a call centre in Romania, I describe three processes: sleep desynchronization, i.e. working during night and sleeping during the day, synchronization with those having similar nocturnal schedules and, finally, its resynchronization with the mainstream. I describe the tensions and conflicts which accompany each such transformation.

APA, Harvard, Vancouver, ISO, and other styles

33

Staretu, Ionel, and Sebastian Jitariu. "Reconfigurable Anthropomorphic Gripper with Three Fingers: Synthesis, Analysis, and Simulation." Applied Mechanics and Materials 762 (May 2015): 75–82. http://dx.doi.org/10.4028/www.scientific.net/amm.762.75.

Full text

Abstract:

This paper shows the steps of structural synthesis and analysis, kinematic synthesis and analysis and CAD constructive design of a reconfigurable modular anthropomorphic gripper with three fingers. Modularity refers to the fact that the gripper variants can be obtained with only two modules, namely a platform and a finger. Reconfigurability refers to the fact that the main variants of the gripper can be obtained by changing the relative position of the fingers. It is demonstrated that the three-finger gripper has four main configurations that provide important functionality even reported to the functionality of a three-finger gripper with continuous reconfigurability. To verify correct operation, functional CAD simulation is performed, and for dynamic operation simulation, we turn to the advanced software ADAMS. An important advantage of this type of gripper, compared to those with continuous reconfigurability, is much lower price at a relatively good functionality for current robotic gripping operations. The paper makes possible subsequent turn to prototype, testing the gripper operation, as it is mounted on an industrial robot, and optimization of its operation by equipping it with contact sensors. The simulation of the gripper operation in virtual environment and data transmission to the real gripper is a solution of interest that will be studied in future research.

APA, Harvard, Vancouver, ISO, and other styles

34

Wagner, Jon A. "Time-of-Day Variations in the Severity of Injuries Suffered by Mine Shiftworkers." Proceedings of the Human Factors Society Annual Meeting 32, no. 10 (1988): 608–11. http://dx.doi.org/10.1518/107118188786762694.

Full text

Abstract:

One means of assessing the hazard risk associated with mine work is to study the severity of injuries that occur during the course of the workday. Of special interest is the accident risk inherent in night work and rotating shiftwork. To better understand this risk, the Bureau of Mines conducted a study of accidents that occurred during a 10-year period in the taconite (iron) mining operations of the U.S. Lake Superior iron ore region. In general, accidents that occurred during the night shift resulted in more days lost per accident, compared with either the day or afternoon shifts. To control for the possibility of different accident types occurring on different shifts, part of this study focused on accidents involving equipment operation. Again, night shift accidents were shown to be significantly more severe than on the other two shifts. These results implicate work performance during night hours as being relatively impaired, perhaps due to lowered states of psychophysiological arousal, coupled with the handicap of operating in a darkened environment.

APA, Harvard, Vancouver, ISO, and other styles

35

Viriya, Pichetjamroen, Naras Yongyuth, and Kouki Matsuse. "Analysis of Two Continuous Control Regions of Conventional Phase Shift and Transition Phase Shift for Induction Heating Inverter under ZVS and NON-ZVS Operation." IEEE Transactions on Power Electronics 23, no. 6 (2008): 2794–805. http://dx.doi.org/10.1109/tpel.2008.2004037.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Won, Sae-Yeon, Daniel Dubinski, Bedjan Behmanesh, et al. "Clinical Relevance of Seizure in Pediatric Patients with Isolated Acute Subdural Hematoma without Parenchymal Brain Injury." Journal of Neurological Surgery Part A: Central European Neurosurgery 80, no. 04 (2019): 233–39. http://dx.doi.org/10.1055/s-0039-1677824.

Full text

Abstract:

Purpose Isolated acute subdural hematoma (aSDH) in pediatric patients is rare, but it has a major impact on outcome. The purpose of this study was to determine incidence, seizure risk factors, and the outcome of pediatric patients with aSDH. Methods Within a 10-year period (2007–2016), 10 children with aSDH were identified. Baseline characteristics and these parameters were analyzed: pediatric Glasgow Coma Scale (pGCS) score at admission and 24 hours after the operation, hematoma volume/side, and midline shift. Functional outcome was assessed at 3-month follow-up using the King's Outcome Scale for Childhood Head Injury score. Results Three subgroups were identified depending on age and etiology: birth-associated, nontraumatic, and traumatic aSDH. The overall incidence of seizures was 60%, and an even higher rate (75%) was observed in children < 1 month of age. Of those patients, two (67%) developed late seizures. Significant predictors for seizures were low pGCS score at admission (p = 0.03) and 24 hours after surgery (p = 0.03) as well as increased midline shift (p = 0.02). Patients with seizures tended to have an unfavorable outcome. Conclusion Pediatric patients with aSDH are at high risk for seizures, particularly if the pGCS score is low at admission/24 hours after the operation and midline shows a shift. Determining seizure-prone pediatric patients may facilitate early antiepileptic treatment and promote better clinical outcomes.

APA, Harvard, Vancouver, ISO, and other styles

37

Gupta, Jatinder N. D., Christos P. Koulamas, George J. Kyparisis, Chris N. Potts, and Vitaly A. Strusevich. "Scheduling Three-Operation Jobs in a Two-Machine Flow Shop to Minimize Makespan." Annals of Operations Research 129, no. 1-4 (2004): 171–85. http://dx.doi.org/10.1023/b:anor.0000030687.72169.c7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Janardhanan, K. V., K. K. Mukundan, and K. S. V. Shenoy. "A Three Beam HF Phased Array Antenna Capable of Two Frequency Harmonic Operation." IETE Journal of Research 47, no. 5 (2001): 241–46. http://dx.doi.org/10.1080/03772063.2001.11416233.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Scheps, Richard, and Joseph F. Myers. "Simultaneous three-wavelength operation of a coupled-cavity laser containing two gain elements." Optical Materials 3, no. 2 (1994): 129–38. http://dx.doi.org/10.1016/0925-3467(94)90016-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Lee, Gi-Ho, Jae-Young Park, Seung-Jun Ham, and Young-Jin Kim. "Comparative Study on Optimization Solvers for Implementation of a Two-Stage Economic Dispatch Strategy in a Microgrid Energy Management System." Energies 13, no. 5 (2020): 1096. http://dx.doi.org/10.3390/en13051096.

Full text

Abstract:

A microgrid energy management system (MEMS) optimally schedules the operation of dispatchable distributed energy resources to minimize the operation costs of microgrids (MGs) via an economic dispatch (ED). Actual ED implementation in the MEMS relies on an optimization software package called an optimization solver. This paper presents a comparative study of optimization solvers to investigate their suitability for ED implementation in the MEMS. Four optimization solvers, including commercial as well as open-source-based ones, were compared in terms of their computational capability and optimization results for ED. Two-stage scheduling was applied for the ED strategy, whereby a mixed-integer programming problem was solved to yield the optimal operation schedule of battery-based energy storage systems. In the first stage, the optimal schedule is identified one day before the operating day; in the second stage, the optimal schedule is updated every 5 min during actual operation to compensate for operational uncertainties. A modularized programming strategy was also introduced to allow for a comparison between the optimization solvers and efficient writing of codes. Comparative simulation case studies were conducted on three test-bed MGs to evaluate the optimization results and computation times of the compared optimization solvers.

APA, Harvard, Vancouver, ISO, and other styles

41

Kruszyński, Bartosz. "The Kiev operation and Tukhachevsky’s two offensives in 1920 as attempts at undertaking strategic and operational initiative during the Polish-Soviet War of 1919-1920." Open Military Studies 1, no. 1 (2020): 88–103. http://dx.doi.org/10.1515/openms-2020-0112.

Full text

Abstract:

Abstract The article is an analysis of: 1) the Kiev operation from late April and early May 1920, 2) Tukhachevsky’s first offensive in May 1920, 3) Tukhachevsky’s second offensive launched in July 1920. All the three operations were attempts at undertaking strategic and operational initiative during the Polish-Soviet War of 1919-1920. The first offensive pertained to the Polish army, in the subsequent two cases it was the Soviet Western Front. Tukhachevsky’s second offensive resulted in the battle of the Bug in late July and early August 1920. By discussing each of the operations, the author presents the fighting potential of the armies involved, the tactical and operational goals, the course of the fighting, the turning points, both parties’ planning mistakes and the consequences of the operations.

APA, Harvard, Vancouver, ISO, and other styles

42

Lin, Jing-Yuan, Kuan-Hung Chen, Pin-Hsian Liu, Hsuan-Yu Yueh, and Yi-Feng Lin. "Current Sharing Control of an Interleaved Three-Phase Series-Resonant Converter with Phase Shift Modulation." Energies 14, no. 9 (2021): 2470. http://dx.doi.org/10.3390/en14092470.

Full text

Abstract:

Recently, three-phase series-resonant converters (SRCs) have been proposed for high power applications. Three-phase SRCs can achieve zero-voltage-switching (ZVS) of the primary power switches and regulate the output voltage by pulse-frequency modulation. The interleaving technique is also a conventional method for DC-DC converters to achieve a high power level, reducing the output voltage ripples due to operating out of phase at the same frequency between the two converters. However, an interleaved three-phase SRC cannot easily synchronize switching instants between the two modules due to the component tolerances of circuits. In the proposed control method, phase shift modulation (PSM) is used to solve the output current imbalance caused by component tolerances. The power switches of the converter can also maintain synchronizing switching instants between the two modules. Therefore, the lower output voltage ripple can be achieved. A detailed analysis and design of this new control method for interleaved three-phase SRCs are described. Finally, prototype converters with a 2.4 kW total output were built and successfully tested to verify the feasibility of the current sharing modulation.

APA, Harvard, Vancouver, ISO, and other styles

43

Zhou, Zhou, and Miaohua Huang. "Regenerative braking algorithm for the electric vehicle with a seamless two-speed transmission." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 233, no. 4 (2018): 905–16. http://dx.doi.org/10.1177/0954407018755818.

Full text

Abstract:

Better energy efficiency can be acquired by an appropriate shift operation during the regenerative braking process. In this work, an electric vehicle equipped with a two-speed automated transmission was used as the target vehicle. The transmission consists of two-stage planetary gear sets, a helical gear set, and two brakes. A hierarchical algorithm is presented for the electric vehicle. The upper-level algorithm was synthesized to assign braking force among regenerative braking, friction braking, front axle braking, and rear axle braking. Based on the motor external characteristic and ECE-R13 regulations, the work designed the dynamic distribution strategy for maximum use of regenerative braking. In the medium-level algorithm, the motor speed, efficiency characteristics, and assigned regenerative braking torque from upper-level algorithm were used to analyze the optimal shift points for improving regenerative efficiency. Then, a shift points table was drawn. In the lower-level algorithm, the linear control for the transmission was given to ensure seamless and smooth shifting. Finally, hardware-in-loop simulations were carried out. The results show that the proposed algorithm can improve performance in energy efficiency in the experimental braking events.

APA, Harvard, Vancouver, ISO, and other styles

44

Hering, Stefanie, Nico Schäuble, Thomas M. Buck, et al. "Analysis and Optimization of Two Film-Coated Tablet Production Processes by Computer Simulation: A Case Study." Processes 9, no. 1 (2020): 67. http://dx.doi.org/10.3390/pr9010067.

Full text

Abstract:

Increasing regulatory demands are forcing the pharmaceutical industry to invest its available resources carefully. This is especially challenging for small- and middle-sized companies. Computer simulation software like FlexSim allows one to explore variations in production processes without the need to interrupt the running process. Here, we applied a discrete-event simulation to two approved film-coated tablet production processes. The simulations were performed with FlexSim (FlexSim Deutschland—Ingenieurbüro für Simulationsdienstleistung Ralf Gruber, Kirchlengern, Germany). Process visualization was done using Cmap Tools (Florida Institute for Human and Machine Cognition, Pensacola, FL, USA), and statistical analysis used MiniTab® (Minitab GmbH, Munich, Germany). The most critical elements identified during model building were the model logic, operating schedule, and processing times. These factors were graphically and statistically verified. To optimize the utilization of employees, three different shift systems were simulated, thereby revealing the advantages of two-shift and one-and-a-half-shift systems compared to a one-shift system. Without the need to interrupt any currently running production processes, we found that changing the shift system could save 50–53% of the campaign duration and 9–14% of the labor costs. In summary, we demonstrated that FlexSim, which is mainly used in logistics, can also be advantageously implemented for modeling and optimizing pharmaceutical production processes.

APA, Harvard, Vancouver, ISO, and other styles

45

Arif, Muhammad, Mohsin Shahzad, Jawad Saleem, Waheed Malik, and Abdul Majid. "Single Conversion Stage Three Port High Gain Converter for PV Integration with DC Microgrid." Elektronika ir Elektrotechnika 26, no. 3 (2020): 69–78. http://dx.doi.org/10.5755/j01.eie.26.3.25763.

Full text

Abstract:

A high gain three port converter with a unidirectional port for photovoltaic (PV) side and two bidirectional ports one each for the battery and the DC bus for PV integration to DC microgrid is presented. High gain is achieved by a coupled inductor with switched capacitor, whereas single stage conversion is used between the ports to achieve high efficiency. The proposed converter is modelled in PLECS/MATLAB and the simulated results for various operational modes are validated using a 500 W prototype. For main operating mode, i.e., single input single output (SISO), the efficiency is calculated to be as high as 96 %. Similarly, owing to the reduced number of components, the losses are reduced considerably for different operation modes.

APA, Harvard, Vancouver, ISO, and other styles

46

Widiarto, Wisnu, Mochamad Hariadi, and Eko Mulyanto Yuniarno. "Keyframe Selection of Frame Similarity to Generate Scene Segmentation Based on Point Operation." International Journal of Electrical and Computer Engineering (IJECE) 8, no. 5 (2018): 2839. http://dx.doi.org/10.11591/ijece.v8i5.pp2839-2846.

Full text

Abstract:

<span lang="EN-US">Video segmentation has been done by grouping similar frames according to the threshold. Two-frame similarity calculations have been performed based on several operations on the frame: point operation, spatial operation, geometric operation and arithmatic operation. In this research, similarity calculations have been applied using point operation: frame difference, gamma correction and peak signal to noise ratio. Three-point operation has been performed in accordance with the intensity and pixel frame values. Frame differences have been operated based on the pixel value level. Gamma correction has analyzed pixel values and lighting values. The peak signal to noise ratio (PSNR) has been related to the difference value (noise) between the original frame and the next frame. If the distance difference between the two frames was smaller then the two frames were more similar. If two frames had a higher gamma correction factor, then the correction factor would have an increasingly similar effect on the two frames. If the value of PSNR was greater then the comparison of two frames would be more similar. The combination of the three point operation methods would be able to determine several similar frames incorporated in the same segment</span>

APA, Harvard, Vancouver, ISO, and other styles

47

Xu, Z. L., S. N. He, and Bo Shangguan. "Cracking Mechanism and Retrofit Design of Governing Stage Blades for a Steam Turbine." Key Engineering Materials 392-394 (October 2008): 967–74. http://dx.doi.org/10.4028/www.scientific.net/kem.392-394.967.

Full text

Abstract:

Cracking of blade dovetails occurred in a governing stage of a 50MW steam turbines twice within 5 months. To find out the failure mechanism and measures to avoid the failure accident, one of the cracked blades has been inspected by the metallography and a scanning electronic microscope. The inspection results show that the cracking of the blade is caused by the high cycle fatigue. When governing stage blades are in operation, the vibration of blades can extend to platform or even to dovetail parts over radial supporting surfaces depending on temperature, centrifugal force and assembly tolerance. The calculated results by FEM show that not only natural frequencies of blades in operating are smaller than that in stationary but also the modal order shifts when the blade runs from stationary to operation states. The effect of mode shift on the failure was investigated. According to the conclusion, the blades have been retrofitted by increasing neck of dovetail to avoid dangerous resonance, and the blades have been operating in healthy condition for two years after the modification. Contrarily, if the phenomenon of mode shift were ignored, it would be difficult to find out the right reason of resonance and ways to retrofit the damaged blades.

APA, Harvard, Vancouver, ISO, and other styles

48

Cheng, Wen Ming. "Study of System Design Based on Three Machine Vision of Three Axis Dispensing." Advanced Materials Research 1079-1080 (December 2014): 860–63. http://dx.doi.org/10.4028/www.scientific.net/amr.1079-1080.860.

Full text

Abstract:

With the rapid development of computer technology and electronic technology, the future will be a large number of the use of automation equipment instead of manual operation, to meet the complex control, high precision, multi axis motion control card applied in NC system will become more and more widely. This paper studies three axis dispensing machine positioning control system based on machine vision, not only uses CCD camera to clear description sheet dispensing area real time scanning, using the smoothing operation and the value of the two methods for the acquisition of image preprocessing, and the use of image morphological operation extraction dispensing location coordinates, to solve the traditional dispensing mode of open loop low control accuracy, low efficiency and poor stability problem. Experimental results show that this system is tested and used are able to meet the requirements, in the long time repetition work greatly reduce the use of artificial also can greatly improve the production efficiency and product quality are improved.

APA, Harvard, Vancouver, ISO, and other styles

49

Trafton, Paul R., and Judith S. Zawojewski. "Implementing The Standards: Meanings of Operations." Arithmetic Teacher 38, no. 3 (1990): 18–22. http://dx.doi.org/10.5951/at.38.3.0018.

Full text

Abstract:

“Carlos finally understands subtraction! He got nine of the ten exercises correct, and every one of them involved renaming.” Statements like this confuse students' computational proficiency with their understanding of an operation. Ironically, this student's understanding of the operation of subtraction may be very shallow. We often give too little attention to building and assessing concepts of operations, yet this is one of three important components of teaching and learning about number that are included in the NCTM's Curriculum and Evaluation Standards for School Mathematics (1989). The first of the three components is the standard on number sense and numeration. Concepts of operations (see table 1) is the second and builds on number sense. The third of the three number standards, whole-number computation, must build on the other two areas. A deep understanding of the concepts associated with an operation results from careful attention to many important real-world and mathematical ideas and relationships.

APA, Harvard, Vancouver, ISO, and other styles

50

Lin, Bertrand M. T., F. J. Hwang, and Jatinder N. D. Gupta. "Two-machine flowshop scheduling with three-operation jobs subject to a fixed job sequence." Journal of Scheduling 20, no. 3 (2016): 293–302. http://dx.doi.org/10.1007/s10951-016-0493-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Two and three-shift operation'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles