Spacing Uniformity Research Articles

Coexisting Ordered States, Local Equilibrium-like Domains, and Broken Ergodicity in a Non-turbulent Rayleigh-B\xe9nard Convection at Steady-state

A challenge in fundamental physics and especially in thermodynamics is to understand emergent order in far-from-equilibrium systems. While at equilibrium, temperature plays the role of a key thermodynamic variable whose uniformity in space and time defines the equilibrium state the system is in, this is not the case in a far-from-equilibrium driven system. When energy flows through a finite system at steady-state, temperature takes on a time-independent but spatially varying character. In this study, the convection patterns of a Rayleigh-Bénard fluid cell at steady-state is used as a prototype system where the temperature profile and fluctuations are measured spatio-temporally. The thermal data is obtained by performing high-resolution real-time infrared calorimetry on the convection system as it is first driven out-of-equilibrium when the power is applied, achieves steady-state, and then as it gradually relaxes back to room temperature equilibrium when the power is removed. Our study provides new experimental data on the non-trivial nature of thermal fluctuations when stable complex convective structures emerge. The thermal analysis of these convective cells at steady-state further yield local equilibrium-like statistics. In conclusion, these results correlate the spatial ordering of the convective cells with the evolution of the system’s temperature manifold.

Robust edge-spread function construction methods to counter poor sample spacing uniformity in the slanted-edge method.

The slanted-edge method describes an algorithm for measuring the spatial frequency response of digital imaging systems. The method can be applied to edges oriented at nearly any angle, but there are some angles that cause simplistic implementations of the algorithm to fail, or produce inaccurate measurements. These angle-dependent phenomena are demonstrated to stem from a lack of uniformity in supersample spacing in the edge-spread function. Two well-known slanted-edge implementation variants are adapted to minimize edge-orientation-dependent errors. These robust slanted-edge implementations are demonstrated to yield accurate measurements, regardless of edge orientation angle or moderate image noise.

Spatial Uniformity Assessment of Particles Distributed in a Spherical Fuel Element Using a Non-Destructive Approach

In many manufacturing procedures, a large number of identical particles need to be disseminated uniformly into a given space. The uniformity of the spatial distribution of the particles can be critical to the properties of the final products. We proposed an image processing-based non-destructive technique to evaluate the particles’ spatial uniformity in a spherical space imaged with computed tomography. Both graphic (qualitative) and numerical (quantitative) methods were developed to demonstrate the (non-) uniformity of the particles. Simulation results indicated that the technique helped detecting the non-uniformity in the particles’ spatial distribution accurately. We conclude that the proposed technique can be used to test whether a number of particles in a sphere are uniformly distributed statistically and graphically.

Effects of seed furrow liquid spraying device on sowing quality and seedling growth of maize

The two cultivation patterns, no-tillage and ridge cultivation, are widely used in maize planting in Northeast China. However, the seed bounce in the falling process and drought seriously at the seedling stage often occur to affect the sowing quality, mean emergence time, percentage of emergence, root biomass, aboveground biomass and root shoot ratio of maize, and eventually reduces the grain yield. To solve the problems, a seed furrow liquid spraying device was designed and thereby the effects of spraying water volumes [0 L/m (V0), 0.6 L/m (V1), 1.2 L/m (V2) and 1.8 L/m (V3)] and nozzle types [conical nozzle (N1) and sectorial nozzle (N2)] on the sowing quality and seedling growth of maize were studied. The water volume and nozzle type had significant effects on the sowing quality (QR, CV, LD), not seedling growth (MET, PE, RB, AB, RSR) (p V2 > V1 > V0). However, the variability coefficient of seed spacing and lateral deviation of seed position were the opposite. The larger spraying water volume led to shorter mean emergence time (V0 > V1 > V2 > V3) and higher percentage of emergence (V3 > V2 > V1 > V0). The root biomass and aboveground biomass increased significantly with the enlargement of spraying water volume. Under different water volumes, the root shoot ratio differed significantly. The plants in the V1, V2 and V3 treatments had lower root shoot ratios compared with the V0 treatment. The increase of spraying water volume significantly reduced the root shoot ratio. The seed furrow liquid spraying device provides a reference for improving sowing quality and promoting seedling growth. Keywords: seed bounce, drought, spraying water volume, nozzle type, seed spacing uniformity, root shoot ratio DOI: 10.25165/j.ijabe.20191202.3799 Citation: Wang W J, Wang W P, Jia H L, Zhuang J, Wang Q. Effects of seed furrow liquid spraying device on sowing quality and seedling growth of maize. Int J Agric & Biol Eng, 2019; 12(2): 68–74.

Secure multilevel permutation-diffusion based image encryption using chaotic and hyper-chaotic maps

This paper proposes a technique that encrypt images using chaotic and hyper-chaotic maps. To attain a high level of security and to get a better encryption effect, the proposed technique performs multilevel permutation and diffusion operations such as block, pixel, and bit-level to encrypt images. In this technique, block-level permutation operation is first performed using Alpar’s map followed by Arnold cat map based pixel-level permutations. Finally, in the permutation stage, hyper-chaotic map based bit-level shuffling operation is performed for over strengthening of the encryption system. To make the ciphertext totally independent of the plaintext, the proposed scheme performs all the three levels of diffusion operations such as bit, pixel, and block-level. In the diffusion stage, Piece-wise Linear Chaotic Map (PWLCM) based bit-level diffusion operation is first performed followed by pixel-level diffusion operation. Finally, block-level diffusion operation is performed to get encryption output. In each of the levels of encryption operation, a hash value (256-bits) of plaintext is used to strongly resist the algorithm against known-plaintext attack and chosen-plaintext attack. The security analyses and computer simulations indicate the good encryption outputs, higher key space and gray scale uniformity, stronger resistance of entropy, differential, and statistical attacks as well as fewer computations to perform encryption operation. This proves the strong ability of the proposed scheme to encrypt gray scale images.

Fluid flow and heat transfer of cross flow hollow fiber membrane contactors with randomly distributed fibers: A topological study

Fluid flow and heat transfer in novel cross flow hollow fiber membrane contactors are studied. The fiber banks are randomly potted in contactor shells and their distribution topology varies from case to case. The packing densities and the inlet flow Reynolds numbers are from 0.35 to 0.5 and 20 to 180, respectively. It is found that the pressure drops and heat transfer coefficients of the contactors are correlated to the topological characteristics of the void spaces among the fibers. Especially, the topological features of the large cavities among the fibers show dominant effect. Two typical large cavities are identified, namely isolated cavities and cut-through cavities. Two non-dimensional parameters σ and γ, which are based on the Delaunay subdivision of the cross sectional images of a contactor, are used to characterize the topological features of the void spaces among the fibers. The σ and γ characterize the uniformity of the void spaces and the channel size of the cut-through cavities, respectively. The pressure drops/Nusselt numbers of a contactor exhibit power law relations to the topological parameter γ. The constants in correlations are found to be dependent on the packing densities. The results can be used to predict the pressure drops and Nusselt number of those massively produced hollow fiber membrane contactors with randomly distributed fibers. Solid inserts that are used to reduce the size of cut-through cavities are suggested.

Effects of seed furrow liquid spraying device on sowing quality and seedling growth of maize

The two cultivation patterns, no-tillage and ridge cultivation, are widely used in maize planting in Northeast China. However, the seed bounce in the falling process and drought seriously at the seedling stage often occur to affect the sowing quality, mean emergence time, percentage of emergence, root biomass, aboveground biomass and root shoot ratio of maize, and eventually reduces the grain yield. To solve the problems, a seed furrow liquid spraying device was designed and thereby the effects of spraying water volumes [0 L/m (V0), 0.6 L/m (V1), 1.2 L/m (V2) and 1.8 L/m (V3)] and nozzle types [conical nozzle (N1) and sectorial nozzle (N2)] on the sowing quality and seedling growth of maize were studied. The water volume and nozzle type had significant effects on the sowing quality (QR, CV, LD), not seedling growth (MET, PE, RB, AB, RSR) (p V2 > V1 > V0). However, the variability coefficient of seed spacing and lateral deviation of seed position were the opposite. The larger spraying water volume led to shorter mean emergence time (V0 > V1 > V2 > V3) and higher percentage of emergence (V3 > V2 > V1 > V0). The root biomass and aboveground biomass increased significantly with the enlargement of spraying water volume. Under different water volumes, the root shoot ratio differed significantly. The plants in the V1, V2 and V3 treatments had lower root shoot ratios compared with the V0 treatment. The increase of spraying water volume significantly reduced the root shoot ratio. The seed furrow liquid spraying device provides a reference for improving sowing quality and promoting seedling growth. Keywords: seed bounce, drought, spraying water volume, nozzle type, seed spacing uniformity, root shoot ratio DOI: 10.25165/j.ijabe.20191202.3799 Citation: Wang W J, Wang W P, Jia H L, Zhuang J, Wang Q. Effects of seed furrow liquid spraying device on sowing quality and seedling growth of maize. Int J Agric & Biol Eng, 2019; 12(2): 68–74.

The Effect of Seed Drill Vibration on the Seed Spacing Uniformity in Row in Lentil Planting

Sıra üzeri tohum dağılım düzgünlüğü, bitkinin gelişimine ve verimine etkili önemli parametrelerden biridir. Sıra üzeri tohum dağılım düzgünlüğünün bulunmasında, laboratuvar ortamında yapışkan bant deneme düzeneğinden yararlanılır. Bu çalışmada, mercimek tohumunun normal sıraya ekiminde, ekim makinası titreşiminin sıra üzeri tohum dağılım düzgünlüğüne olan etkisi incelenmiştir. Ekim makinası titreşiminin sıra üzeri tohum dağılım düzgünlüğüne olan etkisini saptanmak için, normal sıraya ekimde kullanılan λ iyilik kriteri ve Vf varyasyon faktörü değerlerinden yararlanılmıştır. Araştırma sonuçlarına göre, titreşimin etkisiyle sıra üzeri tohum dağılım düzgünlüğünün kötüleştiği belirlenmiştir. Varyasyon faktörü değeri (Vf) 1.1’den büyük çıkarak sıra üzeri tohum dağılımını, poisson karakterinden negatif binomiyal karaktere dönüştürmüştür. İyilik kriterine (λ) göre yapılan değerlendirmede ise titreşimin etkisiyle sıra üzeri tohum dağılım düzgünlüğü oranının %55 sınır değerinin altında kalmasına (yetersiz) neden olmuştur.

Discovery of parabolic microresonators produced via fiber tapering.

We demonstrate a new method for the creation of surface nanoscale axial photonics (SNAP) microresonators with harmonic profiles via fiber tapering in a laser-heated microfurnace. This simple procedure makes microresonators that support hundreds of axial modes with good spacing uniformity, yielding a promising prospective method for fabricating miniature frequency comb generators and dispersionless delay lines.

Rapeseed Seedling Stand Counting and Seeding Performance Evaluation at Two Early Growth Stages Based on Unmanned Aerial Vehicle Imagery.

The development of unmanned aerial vehicles (UAVs) and image processing algorithms for field-based phenotyping offers a non-invasive and effective technology to obtain plant growth traits such as canopy cover and plant height in fields. Crop seedling stand count in early growth stages is important not only for determining plant emergence, but also for planning other related agronomic practices. The main objective of this research was to develop practical and rapid remote sensing methods for early growth stage stand counting to evaluate mechanically seeded rapeseed (Brassica napus L.) seedlings. Rapeseed was seeded in a field by three different seeding devices. A digital single-lens reflex camera was installed on an UAV platform to capture ultrahigh resolution RGB images at two growth stages when most rapeseed plants had at least two leaves. Rapeseed plant objects were segmented from images of vegetation indices using typical Otsu thresholding method. After segmentation, shape features such as area, length-width ratio and elliptic fit were extracted from the segmented rapeseed plant objects to establish regression models of seedling stand count. Three row characteristics (the coefficient of variation of row spacing uniformity, the error rate of the row spacing and the coefficient of variation of seedling uniformity) were further calculated for seeding performance evaluation after crop row detection. Results demonstrated that shape features had strong correlations with ground-measured seedling stand count. The regression models achieved R-squared values of 0.845 and 0.867, respectively, for the two growth stages. The mean absolute errors of total stand count were 9.79 and 5.11% for the two respective stages. A single model over these two stages had an R-squared value of 0.846, and the total number of rapeseed plants was also accurately estimated with an average relative error of 6.83%. Moreover, the calculated row characteristics were demonstrated to be useful in recognizing areas of failed germination possibly resulted from skipped or ineffective planting. In summary, this study developed practical UAV-based remote sensing methods and demonstrated the feasibility of using the methods for rapeseed seedling stand counting and mechanical seeding performance evaluation at early growth stages.

Effects of wheat residue and depth-control mechanism of no-till seeder on corn sowing performance

No-till planting can promote soil and water conservation and has gradually been adopted on the North China Plain where an annual wheat–corn double cropping system serves as the main cropping system. Corn is planted in June immediately after the winter wheat harvest so that fields are covered with wheat residues. The presence of wheat straw makes it difficult to maintain uniform corn seed spacing and sowing depth. To overcome these problems, a new seeder unit has been developed with a depth-control mechanism on a single-sided gauge wheel. A study was conducted to compare the performance of this seeder unit with two conventional seeder units (with depth-control mechanisms using double-sided gauge wheels and a rear gauge wheel) by testing in fields with two different amounts of residue (0.78 kg/m2 and 0.64 kg/m2). Seed spacing, sowing depth, and emergence time were measured after planting. The results indicate that the newly designed seeder unit with a single-sided gauge wheel performs better on seed spacing, sowing depth and emergence time uniformity, particularly in fields with a small amount of residue, with the quality of feed index, quality of sowing depth index and quality of emergence time index of 91.90%, 95.45% and 87.87%, respectively. The new seeder unit can meet the requirements of no-till planting for corn.

Design and experimental study of seed precise delivery mechanism for high-speed maize planter

Aiming at improving the seed spacing uniformity of maize planter at high forward speed, a seed precise delivery mechanism driven by electric motor has been developed and evaluated in laboratory. The mechanism was designed to deliver single seed from seed meter to furrow. Seed’s movement from the seed release point in a seed meter to the seed delivery cavity in the belt was analyzed, the mathematical model of seed movement in the seed precise delivery mechanism was established based on seed delivery time analysis. A mechanical prototype was designed and associated control system was developed. The performance contrast experiment was conducted between a traditional seed tube and newly developed seed precise delivery mechanism, and test results indicated that the qualities of feed index of the seed precise delivery mechanism were higher than those of the traditional seed tube delivery mechanism, and the coefficients of variation of the seed precise delivery mechanism were lower than those of the traditional seed tube delivery mechanism when the forward speed of planter was set at 10 km/h, 12 km/h and 14 km/h, respectively. It indicated the seed precise delivery mechanism significantly improved seed spacing uniformity of maize planter compared with the traditional seed tube delivery mechanism. Keywords: seed precise delivery mechanism, electric motor, seed spacing uniformity, delivery time, mechanical prototype DOI: 10.25165/j.ijabe.20181104.2802 Citation: Liu Q W, Cui T, Zhang D X, Yang L, Wang Y X, He X T, et al. Design and experimental study of seed precise delivery mechanism for high-speed maize planter. Int J Agric & Biol Eng, 2018; 11(4): 81-87.

Short-period fluctuation and spatial distribution of solar irradiance under clouds

Recently, outdoor photovoltaic (PV) module performance characterizations have been carried out mainly for testing installed PV modules. For high-accuracy outdoor measurement, solar irradiance with stability in time and uniformity in space are required. Short-period temporal instability and spatial nonuniformity of solar irradiance are observed using a series of PV module sensors (PVMSs). The speed and direction of cloud shadows moving on PVMSs are evaluated from the fluctuations of irradiance detected by several PVMSs. On the basis of cloud distribution, weather conditions are classified into four types, and the characteristics of solar irradiance fluctuations are examined for each type. The irradiance changes quickly under cumulous clouds. On the other hand, the irradiance becomes weak, but its short-period fluctuations are not evident under layered clouds. The amplitude of irradiance fluctuations reaches 70% of clear-day irradiance at noon in this observation. The spatial nonuniformity evaluated on the basis of the instantaneous difference in irradiance intensity between two PVMSs also reaches 1.8%/m of clear-day irradiance.

Prototype twin vacuum disk metering unit for improved seed spacing uniformity performance at high forward speeds

The objective of this study was to design and develop a prototype twin vacuum disk metering unit so that seeding can be achieved at higher forward speeds while reducing the peripheral speed of the vacuum disk for improved seed spacing uniformity performance and increased field work capacity. In order to meet this objective, a new precision seeding unit with twin vacuum disks, each being a mirrored view of the other and geometrically the same, was designed in animated drafting software and then it was manufactured and used for the laboratory experiments. Three crop seeds were used to determine the performance of the new metering unit in the lab on a sticky belt test stand. Two alternative measures were used to quantify the seed spacing accuracy, and polynomial functions using the principles of response surface methodology were developed to calculate the optimum level of the variables. The tests performed in the laboratory at 2, 3, and 4 ms-1 forward speeds resulted in improved seed spacing accuracy values, while the quality of feed index measure went down once the forward speed increased from 2 to 4 ms-1. The quality of feed index with the new metering unit was obtained to be 100% at 2 ms-1, while it was almost 98% for all crop seeds at 3 ms-1. The forward speed of 4 ms-1 resulted in quality of feed index values of 92%, 96%, and 96% for cotton, sunflower, and corn seeds, respectively.

Quantization noise as a determinant for color thresholds in machine vision.

Color discrimination simulation is applied to study a uniformity of the color space of machine vision devices whose operation is based on a three-component color model and which involve analog-to-digital conversion of signals with a resolution of 8 bits per channel. Algorithms for finding the intervals of the dominant wavelength and color saturation of a specimen are developed. The spectral dependence of intervals of color parameters calculated using the digital images is found. It is shown that machine vision possesses the color discrimination thresholds, which can be drawn in the CIE1931 xy chromaticity diagram in the form of equal-contrast ellipses similar to the MacAdam ellipses. At resolution of 6 bits, the size of a reference MacAdam's ellipse is a little less than that of the machine vision ellipse's sizes, and at resolution of 7 bits, it is a little more than that of the machine vision ellipse's sizes. A hypothesis is proposed that implies that the process of an encoding of the visual neural signals may include procedures similar to an analog-to-digital conversion.

Real time laboratory and field monitoring of the effect of the operational parameters on seed falling speed and trajectory of pneumatic planter

Laboratory tests are usually carried out with different technologies and under quite different conditions to field tests. In this study, a laboratory test was proposed to assess seed spacing uniformity which is applicable in a field situation. In this method, a high-speed camera system was used to detect seed falling trajectory, which is an effective factor on uniformity of seed spacing in both conditions of laboratory and field. Experiments were performed with four pressures (30, 40, 50 & 60 kPa) two forward speed ranges (3 to 4.5 km/h and 6 to 8.5 km/h) and two types of seed (maize and castor) under two conditions of laboratory and field. Results revealed that the highest value of quality of feed for the seed of castor with mean of 98.31% (at forward speed of 3.0 to 4.5 km/h and 4.0 kPa vacuum pressures), and for maize seed with mean of 80% (at 3.0–4.5 km/h and 4.0 kPa) were obtained under laboratory and field conditional, respectively. To determine the locations of seed in the different frames, equations of seed trajectories were first obtained for every treatment and then a general equation was extracted from the entire data set of treatments. This equation is: y=3.523e-0.077x with value for coefficient of determination, R2 = 0.902. The results show that under operating speed range of 3 to 4.5 km/h, seed spacing uniformity for different treatments of both seeds is statistically the same at 95% confidence level both in the laboratory and in the field. At a forward speed of 6 to 8.5 km/h and 4 levels of vacuum pressure, the difference among calculated mean and actual mean of speeds of fall is statistically significant at 5% probability level.

Effect of Riverbed Morphology on Lateral Sediment Distribution in Estuaries

ABSTRACT Yang, Z.; Cheng, H.; Cao, Z.; Guo, X., and Shi, X., 2018. Effect of riverbed morphology on lateral sediment distribution in estuaries. An idealized model is applied to a set of eight estuaries with various transverse depth cross-sections to examine the effect of riverbed morphology on suspended sediment concentration (SSC) distribution. Five estuaries consist of a single deep channel, and three estuaries consist of double deep channels. All estuaries share a set of boundary conditions, including tidal flow, density gradient, river discharge, in an attempt to represent a typical estuary. Under these conditions, model results suggest that both tidal and residual flow fields vary significantly among eight estuaries, resulting in significant differences on SSC distribution, e.g., maximum mean SSC (), location of (), and space uniformity of mean SSC. In most estuaries, the SSC is higher over the left channel than that over the right channel mainly due to the lateral density gradient-generated residual...

Development of an electro-mechanic control system for seed-metering unit of single seed corn planters Part II: Field performance

Using single seed planters is important for a uniform distribution of plant growing area. Seed metering units of planters receive their motion from the drive wheel pass through various transmission members such as the chains, gears, shafts and belts. While the planter is being operated, the transmission system of the machine and drive system of the seed metering units naturally push the driving wheel. Because of this effect, the wheel experiences a loss of mobility or some sort of slipping. Consequently, all seed metering units are being affected due to the common mobility transmission system and changes in the desired plant spacing occur. In order to overcome these negativities, an electro-mechanic drive system (EMDS) alternative to classic driving system (CDS) was developed. Detailed information regarding the system design and laboratory simulation results of EMDS were provided in Part I of this study. In this part, it was aimed to investigate the effect of EMDS on the planting quality (plant spacing uniformity, variation among rows) and operational parameters (fuel consumption and negative slippage) in the field and compared with the CDS. While the quality of feed index (Iqf) 90.63%, multiple index (Imult) 0.94%, missing index (Imiss) 8.44% and precision index (Ip) 17.63% were obtained in trials performed by the EMDS, Iqf 88.13%, Imult 2.50%, Imiss 9.38% and Ip 17.81% were found in trials performed by the CDS. Plant spacing uniformity in the EMDS was found as “good” while it was “moderate” in the CDS, according to related criteria. Plant distribution uniformity in the EMDS were better than the CDS. Furthermore, the experimental plant spacing values obtained by the EMDS were closer to the theoretical (set) value than the values obtained by the CDS. The negative slipping in the planter’s drive wheel was found as 1.33% at trials with the EMDS while it was 6.79% with the CDS. When the EMDS used in the field operations, it provided approximately 22% fuel saving compared with the CDS. The results promise that the developed system can be used as an alternative to the CDS for single seed planters. However, in order to provide a complete mechanical rapport between the EMDS and the planter, future studies, various structural improvements in the seed metering unit designs and optimization of the seed plate thickness, number of holes and connection methods may be required.

Superconducting micro-resonator arrays with ideal frequency spacing

We present a wafer trimming technique for producing superconducting micro-resonator arrays with highly uniform frequency spacing. With the light-emitting diode mapper technique demonstrated previously, we first map the measured resonance frequencies to the physical resonators. Then, we fine-tune each resonator's frequency by lithographically trimming a small length, calculated from the deviation of the measured frequency from its design value, from the interdigitated capacitor. We demonstrate this technique on a 127-resonator array made from titanium-nitride and show that the uniformity of frequency spacing is greatly improved. The array yield in terms of frequency collisions improves from 84% to 97%, while the quality factors and noise properties are unaffected. The wafer trimming technique provides an easy-to-implement tool to improve the yield and multiplexing density of large resonator arrays, which is important for various applications in photon detection and quantum computing.

Development of an electro-mechanic control system for seed-metering unit of single seed corn planters Part I: Design and laboratory simulation

The performance of precision planters is very important for attaining uniform seed spacing. While a planter is on work, undesired situations such as spinning and slipping on ground wheel, vibration, seizing and jamming on the chain-sprocket systems may occur during the transfer of the motion from the ground wheel to the seed-metering unit especially at high operating speeds. In order to overcome these problems, it was aimed to develop an electro-mechanic drive system (EMDS) for seed metering units of a classic single seed planter. The performances of the EMDS and the classic drive system (CDS) were tested at three different operating speeds (vf) (5, 7.5, 10 km/h) and ten different seed spacing (zt) from 6 to 29.3 cm at laboratory. Both systems were compared regarding to the seed spacing uniformity. When the EMDS was used, the quality of feed index (Iqf), multiple index (Imult), miss index (Imiss) and precision index (Ip) were ranged as such: 2.91–95.36%, 0–1.73%, 4.45–97.09% and 8.79–22.14%, respectively. At the test of the CDS, the performance indices varied as such: Iqf 2.09–98.55%, Imult 0–0.36% and Imiss 1.09–97.91%, Ip 5.79–20.92%. Seed spacing uniformities were found as “good” and “moderate” for both systems. Average seed spacing values obtained from the EMDS were found to be closer to the theoretical seed spacing values compared with that obtained from the CDS. EMDS enabled the suggested optimum seeding rate, a quick and simple setting possibility, synchronize and real-time control, the ability to work under higher speeds, individual movement and control for each metering unit. However, EMDS should be tested to determine the success of the system in practice. Therefore, the field performance of EMDS with respect to plant spacing uniformity and operational parameters (variation among rows, fuel consumption and negative slippage) were examined in the following part of this study (Part II: Field Performance).