Line In Series Research Articles

Optimization of Scheduling using Heuristic Approach with Campbell Dudek Smith Algorithm (CDS) at PT OSIN

PT OSIN is a company that runs a business in the automotive manufacturing sector. The company applies a flow shop production model whose production pattern is line to line in series using the First Come First Serve production scheduling method. The problem with the FCFS method which is considered to have not reached the optimal enough in meeting uncertain product demands, causing delays in the production schedule, which has an impact on the flow or distribution of goods and can lead to increased production in activities. The proposed improvement method is made to optimize production scheduling, focusing on minimizing the makespan values in the scheduling system's order. This study uses a heuristic approach to the Campbell, Dudek, Smith (CDS) algorithm in overcoming scheduling problems. The CDS method is a production scheduling heuristic method developed from the Johnson algorithm in obtaining several sequences of 6 types of work processes at the work center which aims to analyze the total time for each processing process (makespan). Comparing the two methods using the FCFS method by sorting the scheduling according to the order of the initial order time produces a total value of 2,408.75 minutes, while using the CDS algorithm which uses 5 iterations produces a minor matter of 881.3 minutes. Comparing the results obtained by applying the scheduling system with the CDS method can be used as a proposed improvement in overcoming the delay in delivery and the production scheduling process.

Transient stability enhancement using optimized PI tuning of static synchronous series compensator in wind power conversion system

Power systems are expanding comprehensively with the increase in load demand from both residential and industrial usage. Renewable energy is penetrating the power system to satisfy the power needs of the load demand. With its potential to generate power and compensate for a large portion of the load demand, wind generators make a major renewable power contribution. Power oscillations inherent in wind generator integration with the grid are a power quality issue to be addressed. Oscillation damping using flexible AC transmission system (FACTS) devices is a relevant solution for the power quality issue. There are multiple reasons for power oscillation. Mainly, power systems encounter fault conditions. The faults can be cleared, and the power system tries to retain stability. Sometimes, the system fails due to a longer settling time. A series-connected FACTS device utilized as a series compensator is referred to as a static synchronous series compensator (SSSC). Controlling the flow of electricity over a transmission line using this method is incredibly efficient. The capacity to switch between a capacitive and an inductive reactance characteristic is necessary. The SSSC regulates the flow of power in transmission lines to which it is linked by adjusting both the magnitude of the injected voltage and the phase angle of the injected voltage in series with the transmission line. This allows the SSSC to manage the power flow in the transmission lines. It does it by inserting a voltage that can be controlled into a transmission line in series with the fundamental frequency. This paper develops the optimally tuned SSSC in the wind-integrated grid system to dampen the oscillation. Teacher–learner-based optimization (TLBO) and gray wolf optimization (GWO) algorithms are used to tune the PI controller to improve the damping response. The obtained results show that the damping performance of the proposed controller is better than that of the other traditional controllers.

Optimization of Power Quality Using the Unified Power Quality Conditioner (UPQC) with Unbalanced Loads

The power quality (PQ) is a major issue for both electrical utilities and their customers. The nonlinear loads cause PQ problems like current harmonics, voltage harmonics, frequency deviation, voltage sag and voltage swell. A unified power quality conditioner (UPQC) is utilized in this research to minimize these PQ problems. The UPQC is made up of two active power filters (APFs), one of which is connected to the line in series and the other in parallel. The Unit Vector Template Generation (UVTG) approach is used to control the series APF, whereas the Synchronous Reference Frame (SRF) technique is used to control the shunt APF. The compensating properties of a series-shunt APFs when the loads become imbalanced have been explored. The system performance has been tested under conditions current harmonics, voltage harmonics, voltage sag, and voltage swell. The voltage harmonics are identified and reparation in a series APF using the UVTG technique, whereas the harmonics and unbalanced currents are identified and reparation in a shunt APF using the SRF method. An IEEE-519-compliant THD (Total Harmonic Distortion) of less than 5% is achieved by UPQC in simulations with unbalanced loads. The findings indicate that harmonic currents and supply voltage fluctuations were lessened by UPQC.

A Novel Flexible Fault Current Limiter for DC Distribution Applications

As an effective carrier of new energy collection, DC power grid has characteristics of low inertia and weak damping, which makes DC fault propagate extremely fast. However, the existing protection and DC circuit breaker (DCCB) technique still could not match its fault propagation speed. Therefore, to solve this problem, a novel of flexible fault current limiter (NFFCL) is presented in this paper. Under normal operation condition, NFFCL is connected to DC line in series without negative influence. When a fault occurs to DC line, NFFCL’s rectifier circuit, according to the protection criterion, provides cascade inductor, which is connected to DC line in series, with a set-slope linear current. In this case, the voltage drop between both ends of inductor can be clamped flexibly, which can even completely isolate the fault area. A controlled voltage source (CCVS) is applied to generate inverse flux to prevent the cascading inductor from magnetic saturation. When the fault disappears, the energy of current-limit inductor can be released and transferred to AC power grid through NFFCL’s converter. Finally, simulation cases are carried out to verify the working principles and practicability of proposed NFFCL.

Load Frequency Control of Three area Multi-Unit Deregulated Power System with FOSMC and Performance analysis using Regulation constant

This paper presents three area multi-unit Deregulated Power System (DPS) for Load Frequency Control (LFC) using Fractional Order Sliding Mode Controller (FOSMC) along with Thyristor Controlled Phase Shifters (TCPS) and Superconducting Magnetic Energy Storage (SMES) combination. The FOSMC can be used to overcome nonlinearities and uncertainties of the system for bilateral and unilateral transactions under different Step Load Perturbations (SLPs). The deregulated power system performance is analyzed for different Regulation constants (R) such as 1.8, 2.4 and 3.0. For stabilization of oscillations in frequency and to stabilize the deregulated power system dynamically for different SLPs, TCPS is incorporated with the tie line in series and SMES is used as an energy storage unit. The dynamic responses of LFC problems have been simulated and analyzed with MATLAB/Simulink-based computer simulations. Further simulation results have also been tabulated as a comparative performance with respect to peak overshoot and settling time.

Parasitic Compensation and Hence Isolation Improvement of PIN Diode-Based Switches

This brief presents a transmission line based resonant technique to nullify the parasitic effect of a PIN diode used to design a narrowband high frequency switch. Resonant condition is obtained by using a section of transmission line in series with a single PIN diode in a shunt branch. The method guarantees isolation improvement at any design frequency lower than the series resonant frequency of a diode. It does not use any lumped component other than those required for biasing. Thus, the method greatly improves the high frequency performance of a PIN diode as a switch. A transmission line based analysis is carried out to obtain the design equations. The theoretical prediction is verified by fabrication and measurement. A single-pole-single-throw (SPST) switch using just one single PIN diode provides measured isolation of 40 dB and insertion loss of 1.5 dB at 10.55 GHz. The return loss is more than 20 dB over 10.2-10.8 GHz. A low cost NXP semiconductors BAP64-02 PIN diode with high parasitic and the manufacturer specified highest frequency as 6 GHz is used to show the competency of the proposed method. A second SPST switch using two diodes provides isolation of 72 dB, insertion loss of 1.8 dB and return loss of 35 dB at 10.55 GHz. An SP4T switch is also fabricated and tested. Measured 1 dB compression point for all the switches is higher than 23 dBm.

Research on 3D geological modeling method based on section thinning-densification and close-range photogrammetry

When 3D modeling of the geological body is carried out based on the section, problems such as unable to close the structural plane, slow rendering speed of the model and uneven and long and narrow section triangle network will occur due to the situation of super near point or too dense fold point. To solve the appealing problem, this paper proposes a section thinning-densification method based on the Douglas Peucker algorithm and equidistance algorithm. When processing the original section data, the Douglas Peucker algorithm is used for thinning, and then the equal distance is used for density increase. In this way, the section obtained by thinning-densification method solves the problem of uneven break points on the original section line and does not affect the shape of the section line, effectively solving the problem caused by too dense or too sparse break points on the section line in 3D geological modeling Series of modeling problems. In this paper, through the research on the modeling method of the above ground structure, the application demonstration of the above-ground and underground integrated three-dimensional model construction in Chengdu International Biological city is carried out, which verifies that the above-ground and underground integrated three-dimensional model construction technology is feasible and applicable and worthy of promotion.

A High-Efficiency Inverse Class-F Microwave Rectifier for Wireless Power Transmission

A high-efficiency inverse class-F microwave rectifier for wireless power transmission is described in this letter. The proposed inverse class-F harmonic termination network is realized by connecting a $\lambda /12$ open-ended transmission line in parallel with the diode cathode, and a $\lambda /8$ short-ended transmission line in series with the diode anode. This structure yields a compact layout, and measurement results have demonstrated a peak conversion efficiency of 80.4% for an input power of 13 dBm at 2.35 GHz, and an efficiency larger than 60% within the bandwidth 2.25–3 GHz and for a wide range of output loads.

Determination of full S-parameters of a low-loss two-port device from uncalibrated measurements.

A procedure has been proposed for the determination of full scattering (S-) parameters of a low-loss two-port device using uncalibrated waveguide measurements of four configurations (thru, non-reflecting line, device, and reflection-line with the device). It is shown that to uniquely determine forward and backward reflection S-parameters of the device, S-parameters of a reflecting line (reflection-symmetric or reflection-asymmetric) in series with the device should be used. We first validated our proposed method from simulated S-parameters and then extracted full S-parameters of three different two-port devices [waveguide cells partially loaded by low-loss dielectric samples-polyethylene, polyvinyl chloride, and alumina (with 99.5% concentration) samples] using symmetric and asymmetric reflecting lines. Next, we also compared the complex permittivities of the polyethylene and polyvinyl chloride samples inside two different devices using extracted S-parameters from our formalism with the complex permittivities of the same samples measured by a calibration-dependent method. A good agreement between measured and extracted complex permittivities is observed, demonstrating the accuracy of our proposed method. Finally, we carried out ten independent measurements to determine at each frequency the average and maximum and minimum values (thus changes from the average) of extracted full S-parameters of a low-loss two-port device to evaluate the total uncertainty in measuring these parameters by our method. We note from this analysis that if the S-parameters of a low-loss two-port device will be determined using a reflecting line with symmetric reflections, then attention should be paid in implementing a reflecting line with symmetric reflections since any deviation from the symmetric property of the reflecting line could increase the overall uncertainty.

Unified Power Quality Conditioner Using Injection Capacitors for Voltage Sag Compensation

<p>Power quality has become an important factor in power systems, for consumer and household appliances. The main causes of poor power quality are har ue of achieving active current distortion compensation, power factor monic currents, poor power factor, supply voltage variations etc. A techniq correction and also mitigating the supply voltage variations at load side is compensated by unique device UPQC presented in this thesis. This concept presents a multi loop based controller to compensate power quality problems through a three phase four wire Unified Power Quality Conditioner (UPQC) under unbalanced and distorted load conditions. Here the UPQC is constituted of two Voltage Source Converters (VSC) connected via power link. The series compensator is connected to the line in series and injects the voltage and thus compensates for voltage issues; whereas the shunt compensator injects current thus compensating for current issues, and is connected in shunt to the line. The voltage injection to the line uses an ijecting transformer. The injection transformer is later replaced with injection capacitors, thus eliminating the drawback of conventional UPQC. In this way a good power quality is maintained</p>

Unified Power Quality Conditioner Using Injection Capacitors for Voltage Sag Compensation

<p>Power quality has become an important factor in power systems, for consumer and household appliances. The main causes of poor power quality are harmonic currents, poor power factor, supply voltage variations etc. A technique of achieving both active current distortion compensation, power factor correction and also mitigating the supply voltage variations at load side is compensated by unique device UPQC presented in this thesis. This concept presents a multi loop based controller to compensate power quality problems through a three phase four wire unified power quality conditioner (UPQC) under unbalanced and distorted load conditions. Here the UPQC is constituted of two voltage source converters (VSC) connected via power link. The series compensator is connected to the line in series and injects the voltage and thus compensates for voltage issues; whereas the shunt compensator injects current thus compensating for current issues, and is connected in shunt to the line. The voltage injection to the line uses an injecting transformer. The injection transformer is later replaced with injection capacitors, thus eliminating the drawback of conventional UPQC. In this way a good power quality is maintained.</p>

Pulsed welding plasma source

It is shown that in order to form the current pulse of a near rectangular shape, which provides conversion of the welding arc into a dynamic mode, it is rational to connect a forming element made on the basis of an artificial forming line in series to the welding DC circuit. The paper presents a diagram of a pulsed device for welding with a non-consumable electrode in argon which was developed using the forming element. The conversion of the arc into the dynamic mode is illustrated by the current and voltage oscillograms of the arc gap and the dynamic characteristic of the arc within the interval of one pulse generation time in the arc gap. The background current travels in the interpulse interval.

A Delay Locked Loop With a Feedback Edge Combiner of Duty-Cycle Corrector With a 20%–80% Input Duty Cycle for SDRAMs

A feedback edge combiner is proposed for the duty-cycle corrector (DCC) of a delay locked loop (DLL) to increase the range of allowed input duty cycle. The feedback edge combiner generates the rising edge of a DCC output at the rising edge of an input clock. It generates the falling edge of the DCC output at the rising edge of a feedback clock that is a half-period-delayed signal of the DCC output. A dual-delay-line digitally controlled delay line (DCDL) is used for seamless boundary switching. The chip area of the DCDL is reduced by around 46% by employing the architecture of two short coarse delay lines followed by a fine phase mixer (FPM) and a long coarse delay line in series instead of the architecture of two long coarse delay lines followed by an FPM. The measurements on the chip fabricated in the 65-nm CMOS show the allowed input duty cycle in the range from 20% to 80%; root-mean-square and peak-to-peak jitters of 2.69 and 14.0 ps, respectively, at 2 GHz and 1.2 V; and the operating frequency range from 0.12 to 2.0 GHz at 1.2 V. The measured power consumption is 3.3 mW/GHz at 1.2 V. The chip area is 0.059 mm 2.

Fabrication of Superconducting Mid-Infrared Photodetectors With Dipole Nanoantennas

We have proposed using nanoantennas with superconducting detector to improve the response performance of infrared detectors. Dipole nanoantennas that have an NbN load resistance were fabricated to evaluate the antenna properties. By using electromagnetic simulation, the antenna length was set at 2400 nm for the operation around 7-μm wavelength. The antennas were evaluated by using Fourier transform infrared spectroscopy. In an evaluation of spectral transmission characteristics, clear absorption caused by antenna effects was observed at around 1400 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . The results of the simulation qualitatively agreed with the results of the experiment. The antenna effective area was also evaluated, and the area was estimated to be approximately 5.4 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at 1420 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . We have fabricated a prototype of midinfrared (MIR) photodetectors that were formed with 45 dipole antennas with an NbN strip. The antennas were placed within an area of 20 × 20 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and they were connected by bias line in series. By the irradiation of MIR (λ = 4.9 μm) light, the responses with high polarization dependence values caused by antenna effect were observed.

Role of Lorentz–Stark broadening of hydrogen spectral lines in magnetized plasmas: Applications to magnetic fusion and solar physics

Broadening of hydrogen spectral lines in plasmas is an important diagnostic tool for many applications (here and below by “hydrogen atoms” and “hydrogen spectral lines” we mean atoms and spectral lines of hydrogen, deuterium, and tritium). In magnetized plasmas radiating hydrogen atoms moving with the velocity v across the magnetic field B experience a Lorentz electric field EL=v×B/c in addition to other electric fields. Since the velocity v has a distribution, so does the Lorentz field, thus making an additional contribution to the broadening of spectral lines. Compared to previous studies of this contribution, we cover the following new aspects. First, we consider the Lorentz–Doppler broadening of highly-excited hydrogen lines and produce new analytical results for arbitrary strength of the magnetic field B. We show for the first time that in the high-B case, the π-components of hydrogen lines are significantly suppressed compared to the σ-components. Second, we derive analytically Lorentz-broadened profiles of highly-excited hydrogen lines. We obtain expressions for the principal quantum number nmax of the last observable hydrogen line in the spectral series. These expressions differ very significantly from the corresponding Inglis–Teller result and constitute a new diagnostic method allowing to measure the product T1/2B, where T is the atomic temperature. Third, we consider magnetized plasmas containing a low-frequency electrostatic turbulence. This kind of turbulence causes anomalous transport phenomena (e.g., the anomalous resistivity) and is therefore very important to be diagnosed. We derive analytically distributions of the total electric field and the corresponding Stark profiles of hydrogen lines. We demonstrate that our findings lead to a significantly revised interpretation of the previous and future experimental data in magnetic fusion and the observational data in solar physics.

電力信号フィードバック直列補償器を用いた発電機軸ねじれ共振現象の抑制

Suppression of subsynchronous torsional interaction(SSTI) in electrical power system achieved with insertion of an inverter to transmission line in series. Active power of the transmission line is sensed and filtered by three sets of bandpass filters to get the torsional signal for feedback. The output signal of controller is converted to voltage reference signals for each phase by dq inverse transformation and the voltage reference signals are input to PWM control circuit to generate the gate firing signals for the inserted inverter. Simulation results show the control is effective to suppress the SSTI

How Sommerfeld extended Bohr’s model of the atom (1913–1916)

Sommerfeld’s extension of Bohr’s atomic model was motivated by the quest for a theory of the Zeeman and Stark effects. The crucial idea was that a spectral line is made up of coinciding frequencies which are decomposed in an applied field. In October 1914 Johannes Stark had published the results of his experimental investigation on the splitting of spectral lines in hydrogen (Balmer lines) in electric fields, which showed that the frequency of each Balmer line becomes decomposed into a multiplet of frequencies. The number of lines in such a decomposition grows with the index of the line in the Balmer series. Sommerfeld concluded from this observation that the quantization in Bohr’s model had to be altered in order to allow for such decompositions. He outlined this idea in a lecture in winter 1914/15, but did not publish it. The First World War further delayed its elaboration. When Bohr published new results in autumn 1915, Sommerfeld finally developed his theory in a provisional form in two memoirs which he presented in December 1915 and January 1916 to the Bavarian Academy of Science. In July 1916 he published the refined version in the Annalen der Physik. The focus here is on the preliminary Academy memoirs whose rudimentary form is better suited for a historical approach to Sommerfeld’s atomic theory than the finished Annalen-paper. This introductory essay reconstructs the historical context (mainly based on Sommerfeld’s correspondence). It will become clear that the extension of Bohr’s model did not emerge in a singular stroke of genius but resulted from an evolving process.

Double‐negative reconfigurable resonator with cross‐polarised split rings

Double-negative metamaterials using cross-polarised split-ring resonators in a microstrip line have been implemented. The split-ring resonators comprised quad ring structures and were connected with the microstrip line in series. Four different structures, with the shorted rings in varying locations, were fabricated to demonstrate reconfigurable bandpass characteristics. The effective permittivities and permeabilities were extracted using the Ziolkowski method. Excellent agreement between the developed circuit model and the measurement was observed up to 10 GHz.

A Reconfigurable Compact Coupled Line Multiple-Band Bandpass Filter

This study proposes a circuit structure with reconfigurable multiple bands bandpass filter. This circuit can provide a triple-band or dual-band bandpass facility by adjusting two open stubs (L6 and L7) location. The circuit design used three sections of transmission line in series, the two sets of the coupled lines connected to the gap in each transmission line, and two open stubs in the appropriate locations. The design and manufacturing of the circuit structure is innovative and simple. The center frequencies of the triple-band bandpass filter are set at 2.4, 4.2, and 6.5 GHz, respectively, while the center frequencies of the dual-band bandpass filter are the two lower pass band of the triple-band bandpass filter at 2.4 and 4.2GHz. The filters were simulated using the full-wave electromagnetic simulator, IE3D, and measured by Anritsu-37269D. The simulated and measured results show good agreement in the frequency of interest.

A mythical beast

On the popular US TV series CSI , a rapist almost walks free until crime scene investigators realize he is a chimera: the semen found at the crime scene came from his unborn twin. In an episode of House, MD , doctors tackle the case of a boy, a product of in vitro fertilization, who thinks he has been part of an alien experiment. Conflicting medical tests and the discovery of cells with a different type of DNA are not evidence of alien torture, but rather a sign of the real problem: he is a chimera. On Grey's Anatomy , a tumour turns out to be the testis of a vanished twin, revealing an adolescent to be a hermaphrodite—and a chimera. On All My Children , tests initially indicate that Emma is not Annie's daughter, though Annie swears she gave birth to the girl. A switch in the nursery? No: tissue tests from several organs show Emma is a chimera. The examples do not end there. Over the past few years, US comedies, documentaries and even cartoons have featured chimeric characters, and the condition is now beginning to appear in European programming. > Ironically, although chimerism has long been thought to be rare in humans, the TV writers might have inadvertently got it right Genetics have been a common story line in police series, medical dramas and soap operas for some time. But now that DNA has become mundane, writers are turning to unusual medical conditions such as chimerism to boost their plots. Wikipedia attributes this chimera‐mania to Lawrence Lessig, a law professor at Stanford University (CA, USA), who described chimerism as an underused plot device in his 2004 book Free Culture . Within months, Hollywood responded. Ironically, although chimerism has long been thought to be rare in humans, the TV …