Complete Loop Research Articles

Mechanism of nucleation in ferroelastic domain switching

The mechanism of domain nucleation during ferroelastic domain switching is revealed by utilizing phase-field simulations. A complete compression-tension hysteresis loop is simulated, and the results show the nucleation of new domains at domain walls (DW). Due to relaxation of strain energy, the coherent DWs of the surviving domains often form features like steps, crevices and corners, and nucleation of new domains primarily takes place at these sites in a repeated fashion. The change in elastic strain energy around these sites is sufficient to provide the energy necessary for ferroelastic domain nucleation (FDN). The present simulations reveal that the apparent ellipsoidal shape of a nucleus might be an oblate spheroid when the nucleation takes place at a crevice. The present work also reveals that nucleation of triangular shaped domains is equally probable, and they take place at the steps or corners of DWs.

A complete shortest independent loop set algorithm for model structure analysis

AbstractThis article looks at the well‐known shortest independent loop set algorithm, which is used to identify an independent loop set in system dynamics models. It addresses the cases where the algorithm fails to find a complete set due to its limitation to geodetic cycles and introduces a modification that has the potential to identify a complete independent loop set in every case while maintaining the efficiency of the original algorithm. The modified algorithm uses second‐shortest paths to complete the loop set. Special attention is given to the creation of the second‐shortest path matrix required for the modified algorithm, and to the application of the algorithm to a model where the independent loop set created by the shortest independent loop set algorithm was previously shown to be incomplete. © 2024 System Dynamics Society.

Quantized magnetic flux in a two-band superconducting condensate with a type-Kagome pinning center lattice

In this work we studied the vortex-configuration in a mesoscopic superconducting square in presence of an external magnetic field H applied parallel to its surface vector. We study the magnetization curves in a complete loop, the magnretic induction and the superconducting-electron density for the sample considering Neumann boundary conditions for the order parameter, via length Gennes extrapolation . The sample presents a pinnin center as a Kagome-type laticce at different critical temperature. We solve the generalized time-dependent Ginzburg-Landau equations for a two-condensate system using the Link-variable method considering a Field-Cooling process. Our results show that the vortices are always located at the pinning centers in non-conventional configurations, due to cuopling used.

Spatially-resolved cluster dynamics modeling of irradiation growth

We develop here a spatially resolved, three-dimensional continuum model coupling cluster dynamics (SR-CD) and crystal plasticity to investigate irradiation growth in zirconium. The model uses scale separation to divide the population of the irradiation cluster into mobile and immobile families. Small interstitial and vacancy clusters are modeled using anisotropic reaction–diffusion equations. Among the immobile clusters, an atomistically-informed vacancy cluster to vacancy loop transition is taken into account. The coupling between the evolution equation of CD and the plastic deformation of the material is two-fold, with stress-informed bias factors and local inelastic strains computed from the evolution of the evolving cluster population. The numerical implementation of the model utilizes the finite element method to analyze both single-crystal and polycrystalline samples. The growth strains that are computed align well with the experimental data provided by Carpenter for single-crystal Zr. Furthermore, the transformation of a vacancy cluster into a complete vacancy loop, occurring at a size of 14 nm, is in agreement with experimental observations and atomistic simulations. The density, size, and growth rate of the dislocation loops, denoted as 〈c〉 and 〈a〉, also exhibit good agreement with transmission electron microscopy (TEM) analysis of irradiated Zr and its alloys. Our findings demonstrate that there is a spatial correlation between the growth of these dislocation loops and growth strains, significantly influenced by the crystal size. To explain the expansion of the 〈a〉 axis and the contraction of the 〈c〉 axis in irradiated Zr, it is necessary to consider the diffusion anisotropy difference (DAD) of mobile interstitial species. We show that the PWR Kearns parameters, specifically fr = 0.63, ft = 0.32, fa = 0.05, confer enhanced irradiation resistance to Zr along the principal directions when compared to single crystals. Additionally, reducing the grain size to nanograins further enhances the resistance to irradiation-induced growth, particularly along the direction with the highest volume fraction of basal poles [0001].

Vision-Locomotion Coordination Control for a Powered Lower-Limb Prosthesis Using Fuzzy-Based Dynamic Movement Primitives

An amputee cannot directly use the perceptual visual information to control the movements and gait patterns of his worn prosthesis. In order to help an amputee walk and cross over obstacles smoothly, the paper proposes a vision-locomotion coordination control method for a powered lower-limb prosthesis (PLLP), in which a vision system is proposed to detect obstacles, and a complete vision-locomotion loop is then constructed. With deep learning techniques, the vision system can recognize common obstacles (e.g., garbage cans, bricks and boxes) and obtain the features of obstacles (e.g., distance from obstacles to the depth camera and height of obstacles). Through integrating the vision system into the locomotion control system, the PLLP can make obstacle avoidance decisions and use dynamic movement primitives with type-2 fuzzy models (T2FDMPs) to help amputees cross over obstacles simultaneously. Utilizing the type-2 fuzzy models, smooth trajectories for crossing over obstacles can be obtained. The experimental results show that the PLLP with visual information can switch an amputee’s gaits between level walking and obstacle avoidance adaptively, which demonstrates the effectiveness of the vision-locomotion coordination control system. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —The paper is motivated by the challenge of obstacle avoidance of prostheses. Traditional prostheses cannot achieve autonomous obstacle avoidance because they lack of environmental perception capability. In addition, most prostheses always utilize use the human-robot interaction between amputees and prostheses to recognize the environments. However, due to noise and individual differences, recognition results are not accurate enough. We found that the integration of vision can improve the accuracy and efficiency of environmental recognition. Therefore, it is necessary to construct a complete vision and locomotion closed-loop. In the paper, a vision-locomotion coordination control is proposed, and to make the PLLP cross over obstacles smoothly, a novel trajectory shaping with fuzzy-based dynamic movement primitives is developed. The coordination control is partitioned into the obstacle detection, trajectory shaping and joint control, which can help the PLLP fulfill several obstacle avoidance tasks.

Mother and Daughter Technique Using a Low-Profile Microcatheter for Navigating a Complete Radial Artery Loop

AbstractRadial loops are infrequent; however, they are a major cause for failure of radial access for procedure. Interventionists should be familiar with bail-out techniques when a radial loop is encountered to avoid spasm/injury. We describe our experience with two cases with 360 degrees radial loop in which we used low-profile microcatheter system to successfully complete the procedure

Graphene oxide-DNA/graphene oxide-PDDA sandwiched membranes with neuromorphic function.

The behavior of polyelectrolytes in confined spaces has direct relevance to the protein mediated ion transport in living organisms. In this paper, we govern lithium chloride transport by the interface provided by polyelectrolytes, polycation, poly(diallyldimethylammonium chloride) (PDDA) and, polyanion, double stranded deoxyribonucleic acid (dsDNA), in confined graphene oxide (GO) membranes. Polyelectrolyte-GO interfaces demonstrate neuromorphic functions that were successfully applied with nanochannel ion interactions contributed, resulting in ion memory effects. Excitatory and inhibitory post-synaptic currents were tuned continuously as the number of pulses applied increased accordingly, increasing decay times. Furthermore, we demonstrated the short-term memory of a trained vs untrained device in computation. On account of its simple and safe production along with its robustness and stability, we anticipate our device to be a low dimensional building block for arrays to embed artificial neural networks in hardware for neuromorphic computing. Additionally, incorporating such devices with sensing and actuating parts for a complete feedback loop produces robotics with its own ability to learn by modifying actuation based on sensing data.

Material Removal Mechanism and Evolution of Subsurface Defects during Nanocutting of Monocrystalline Cu

Multigroup large-scalenanocutting models of monocrystalline Cu were established by molecular dynamics simulations to investigate the influence of cutting parameters on the material removal mechanism. The formation and distribution of subsurface defect structures were revealed, and the evolution behavior of the complete prismatic dislocation loop was analyzed in depth. It was demonstrated that the chips and machined surface of monocrystalline Cu were mainly formed under the coupling effect of shearing and extrusion forces. A diamond tool with a larger edge radius or a negative rake angle could produce a noticeable suppression on the chip formation. The corresponding relationship between the location of defect atoms and the distribution of von Mises stress was studied, which indicated that the shear stress would become larger at the subgrain boundaries, dislocation lines, and the amorphous atoms than that in their nearby regions. The complete prismatic dislocation loop was formed by cross-slip between two sets of stacking faults; meanwhile, the generated multiple Lomer–Cottrell locks hindered its movement and promoted the work-hardening phenomenon. These research results are of great theoretical value to enrich the nanocutting mechanism and technology of plastic materials.

Research on a Three-Phase Energy Mutual-Aid Strategy for a Grid-Connected Inverter Based on Constructed Negative Sequence Current Control

With the increased grid-connected capacity of a single-phase distributed power supply, three-phase power unbalance is more likely to occur in a power grid. Three-phase power unbalance can further lead to three-phase voltage unbalance, which can have adverse effects on power quality and power supply reliability. Therefore, there is a need to build a three-phase power transmission channel to realize power exchanging among phases. In this paper, a novel grid-connected inverter control strategy for three-phase power exchanging is proposed based on constructed negative sequence current control. A completed negative sequence current control loop is added to a conventional three-bridge inverter to realize the decoupling control of three-phase grid current, and then three-phase power exchanging is realized. On this basis, this paper further puts forward a strategy for three-phase power exchanging aimed at three-phase voltage balance. Correspondingly, the three-phase grid current is controlled according to the feedback of the three-phase voltage. Then, three-phase voltage balance is achieved by three-phase power exchanging. The simulation and experimental results show that the proposed strategy is suitable for a three-phase unbalanced power grid, which can realize three-phase power exchanging, and further, can achieve three-phase voltage balance. The proposed strategy can help to improve power quality and supply reliability.

Overstrength and plastic rotation of variable cross-section replaceable link

This paper presents a comprehensive investigation of variable cross-section replaceable links (VRLs) through a combination of experimental and numerical analyses. Two types of specimens were designed: one with circular holes in the web plate (C-VRL) and the other with long holes in the web plate (LC-VRL). The performance of VRL specimens with circular and long holes in the web plate were analyzed, focusing on hysteresis curves, energy dissipation capacity, overstrength coefficient, and failure modes. The results showed that the C-VRL specimen exhibited stable and complete hysteresis loops with substantial plastic development and efficient energy dissipation. On the other hand, the LC-VRL specimen experienced reduced bearing capacity due to tearing around the long holes and sliding of the connection between the web plate and the flange. The C-VRL specimen demonstrated higher bearing capacity compared to the LC-VRL specimen, and both specimens exhibited favorable structural ductility. The numerical analysis involved a validated finite element model, considering various parameters such as the length and height of the energy-dissipation region, variable cross-section slope, and weakening form of the web plate. The energy dissipation capacity increased with the rotation angle for all specimens. The overstrength coefficient of the VRLs exceeded the recommended value, indicating its better load-carrying capacity. Overall, the study findings provide insights into the seismic performance, overstrength coefficient, and design considerations of VRLs in practical engineering applications.

Model-free robust decentralised control of multi-input-multi-output nonlinear interconnected dynamic systems

This study presents a generalised framework for model-free robust decentralised control (MFRDC) of interconnected MIMO dynamic systems, with the goal of significantly reducing complexity in model-based design. A model-free robust sliding mode control, by Lyapunov differential inequality, is presented to achieve simultaneous nonlinear, dynamic, interaction/coupling inversion/cancellation (NDII) for such MIMO systems, which treats the plant/process as a total uncertainty from input to output. The U-control platform is presented, to integrate separately independently designed NDII and an invariant controller (IC) into a complete double loop control system. The associated robust stability and other properties are analysed to provide reference for applications. Two simulated tracking control tests are presented for functionally numerical demonstration, validation of the analytical results and illustration of the transparent procedure for general expansion/applications. These are: a coupled inverted pendulum and a two-input and two-output (TITO) non-affine nonlinear dynamic plant.

Numerical investigation on the thermal performance of energy tunnels under groundwater flow and tunnel airflow

The integration of underground tunnels with ground heat exchangers (GHEs), also known as energy tunnels, is a promising technology that has gained attention in energy geotechnics research. This study investigates the coupled effects of groundwater and tunnel-air flows on the energy tunnel system via 3D thermo-hydraulic numerical modelling. It is found that the combination of groundwater flow parallel to the tunnel and limited airflow velocity results in reduced operational efficiency of ground source heat pump (GSHP) due to the strong thermal interference along the tunnel. The study also highlights the importance of real-scale modelling to evaluate the thermal yield of long energy tunnels, particularly when dealing with parallel groundwater flow in geothermal tunnel design.&#x0D; The use of shallow geothermal energy is a renewable solution towards net-zero carbon emissions. In recent years, a variety of conventional geotechnical structures, such as piles, retaining walls and tunnels, have been transformed into energy geostructures to also serve as GHEs to harness renewable energy for space heating and cooling purposes [7]. The thermal performance of energy tunnels is significantly affected by the presence of groundwater flow [1, 6] and the airflow in the tunnel [2, 4]. The groundwater flow and tunnel airflow can both be present in the field, however, their coupled effects on the energy tunnel system are hardly explored in the literature. This study aims to bridge this gap via real-scale numerical investigations.&#x0D; This study uses 3D thermo-hydraulic numerical modelling developed with the finite element package COMSOL Multiphysics [3]. The numerical model was successfully validated against an energy tunnel model-scale laboratory experiment [5]. Figure 1 shows the overall geometry and boundary conditions of the numerical model. A 48 m long tunnel section is thermally activated with the embedment of HDPE pipes (outer diameter of 25 mm and 2.3 mm thickness) placed in the lining segments at a spacing of 200 mm. A single tunnel ring consists of six segments with absorber pipes joined between them. Every four adjacent rings are connected in series to form a complete loop (with a single inlet and outlet), which is then connected in parallel to a flow and return header pipe(s). The entire thermally activated section comprises six loops, with identical fluid inlet temperature and flow rates, as they are fed by the same flow header pipe. The outlet fluid from each loop is mixed along the return header pipe to the GSHP. A constant 36 kW cooling thermal load is applied, and the simulation is run for ten years to allow the system to reach a steady state condition considering the minimum groundwater flow and airflow. The thermal properties of the ground are prescribed as 2 W/(m·K) and 1100 J/(kg∙K) for thermal conductivity and specific heat capacity, respectively.&#x0D; Figure 2 shows the entering water temperature (EWT, header outlet) and the coefficient of performance (COP) of the GSHP after 10 years of operation for different groundwater flow velocities and directions for tunnel air velocities = 0.05 m/s and 2 m/s.&#x0D; Results show that an increase in and leads to a decrease in EWT and an increase in COP. However, the effect of groundwater direction and velocity is more significant when airflow is limited ( = 0.05 m/s). The parallel groundwater flow leads to a higher EWT and lower COP than when the flow is inclined and perpendicular to the longitudinal tunnel axis. Consequently, the thermal performance of the system under parallel flow with a higher can be even worse than the perpendicular and inclined flow with a lower . When = 0.05 m/s, the EWT of parallel flow increases by 15% to 20% compared to the perpendicular flow, resulting in a maximum decrease of 15% in the COP. The effect of groundwater flow is much less significant when airflow is fast ( = 2 m/s): for increases from 0.05 to 2 m/d, EWT and COP change by no more than 13% and 5%, respectively, and the impact of groundwater flow direction is minor.

Experimental Study on Flame Response Characteristics of a Non-Premixed Swirl Model Combustor

Non-premixed swirl combustion has been widely used in pieces of industrial combustion equipment such as industrial boilers, furnaces, and certain specific gas turbine combustors. In recent years, the combustion instability of non-premixed swirl flames has begun receiving attention, yet there is still a lack of related research in academia. Therefore, in this study, we conducted experimental research on a swirl stabilized gas flame model combustor and studied the heat release response characteristics of the swirl combustor through the flame transfer function. Firstly, the flame transfer function (FTF) was measured under different inlet velocities and equivalence ratios, and the experimental results showed that the FTF gain curve of the non-premixed swirl flame exhibited a significant “bimodal” shape, with the gain peaks located around 230 Hz and 330 Hz, respectively. Secondly, two oscillation modes of the flame near the two gain peaks were identified (the acoustic induced vortex mode Mv and the thermoacoustic oscillation mode Ma), which have not been reported in previous studies on swirl non-premixed flames. In addition, we comprehensively analyzed the flame pulsation characteristics under the two oscillation modes. Finally, the coupling degrees between velocity fluctuations, fuel pressure fluctuations, and heat release fluctuations were analyzed using the Rayleigh Index (RI), and it was found that in the acoustic-induced vortex mode, a complete feedback loop was not formed between the combustor and the fuel pipeline, which was the main reason for the significant difference in the pressure fluctuation amplitude near 230 Hz and 330 Hz.

Oral 8 - Does introducing a standardised TURBT template improve the quality of operative notes? A completed loop audit

Oral 8 - Does introducing a standardised TURBT template improve the quality of operative notes? A completed loop audit

A novel survival rat model of hyperkalemia and landiolol induced cardioplegic arrest and resuscitation via cardiopulmonary bypass.

A small animal model would be an effective tool for research on the pathophysiology of cardiopulmonary bypass (CPB). However, numerous CPB models do not involve myocardial arrest and resuscitation. The aim of this research is to establish an easily achievable myocardial arrest and resuscitation CPB model through hyperkalemia and landiolol, simulating clinical cardiac surgery. Ten Sprague-Dawley rats were chosen for CPB. Rats underwent sevoflurane inhalation induction anesthesia and were sustained in an anesthesia state by intubation and intraperitoneal injection's of esketamine and propofol. The entire CPB circuit include a reservoir, a membrane oxygenator and a roller pump, which were connected into a complete loop via silicon tubes and infusion tube.After CPB was established through the tail artery and internal jugular vein, cardioplegic arrest was induced and maintained for 5min at a rectum temperature of 28.5 ± 0.5°C with hyperkalemia and landiolol. Calcium chloride, epinephrine and insulin were then used for resuscitation. All rats successfully finished cardioplegic arrest, resuscitation procedure and survived 2h postoperatively. Mean hematocrit during CPB was significantly lower than physiologic values of the baseline. The mean time of arrest-resuscitation and CPB was 5.4 ± 0.8min and 98.5 ± 5.0min. The blood gas at each detection point were in range with the normal standard requirement of CPB. The establishment of cardioplegic arrest and resuscitation procedure via hyperkalemia and landiolol during CPB of WD rat could be achieved successfully. This animal model could be an alternative organ injury research on organ injury of patients undergoing cardiac surgery.

Updated formulation of magnetic body force in ferrofluids

The magnetic body force is critical for modelling of convection in ferrofluids. Despite a long history in the development of the theories for ferro-hydrodynamics, literature from the last five years shows that a universal consensus has not been reached concerning the formulation of this term for ferrofluids. We present an updated derivation of the body force directly from the Lorentz force and Maxwell's equations. The derivation requires that the differential volume experiencing the body force only contains complete dipole current loops. This has the effect that an additional surface integral term to account for bound surface current is not needed when modelling situations where the ferrofluid has interfaces with other materials. We compare results from our derived body force with five other formulations from the literature for the case of a single conductor in ferrofluid under static and convection conditions. Most formulations become similar in the limit of small magnetic susceptibility. For a susceptibility of the order of 1, as is typical for ferrofluids, the calculated body force from the formulations differed by a factor of about four, greatly affecting thermomagnetic convection predictions for a heated microwire.

Primary sclerosing encapsulating peritonitis: a case report

BackgroundSclerosing encapsulating peritonitis is a rare condition with a typical macroscopic appearance, with fibrocollagenous membrane enclosing loops of the small intestine, causing intestinal obstruction. Unexplained recurrent abdominal pain, obstruction, and a large array of other possible clinical signs and symptoms make sclerosing encapsulating peritonitis a diagnostic challenge.Case presentationA 48-year-old man of Persian ethnicity was admitted multiple times to the emergency surgery department due to recurrent sudden abdominal pain and chronic obstruction without significant findings in medical history or clinical evaluation. Computed tomography was positive for proximal jejunal dilatation and duodenojejunal flexure stenosis due to internal mesenteric hernia. Exploratory laparoscopy, followed by laparotomy, confirmed thick membrane-like fibrous tissue with complete small intestinal loop envelopment. Extensive membrane excision and adhesiolysis was performed, but no mesenteric herniation was found. Early postoperative paralytic ileus with introduction of low-dose steroid therapy, based on histopathological and immunological results, confirming type III sclerosing encapsulating peritonitis, was completely resolved.ConclusionSclerosing encapsulating peritonitis is a rare and difficult-to-diagnose condition, further divided into primary and secondary sclerosing encapsulating peritonitis, on the basis of underlying etiology, dictating treatment modality and prognosis. Intraoperative diagnosis and surgical treatment are mandatory, besides a wide variety of abdominal computed tomography scans, inconclusive results, and clinical presentations. There are so far no known specific markers for the diagnosis of sclerosing encapsulating peritonitis.

A 143 dB Delta-Sigma Modulator for Biomedical Applications

This paper presents a single loop forth-order delta-sigma modulator topology of cascade of integrator with multiple feedback This paper presents a single loop forth-order delta-sigma modulator topology of cascade of integrator with multiple feedback (CIFB) . The number of levels in the quantizer increases for higher performance. The modulator noice transfer function (NTF) and signal transfer function (STF) exploited for higher performance. The out-of-band gain (OBG) of 1.5 selected considering the stability of higher order modulator. The high oversampling ratio (OSR) considered for small bandwidth applications. The maximum quantization noise is suppressed by NTF zeros optimization. A full-scale signal of the modulator is 0.55-V considering the higher order loop filter stability. Due to CIFB topology, there is no peaking in the STF while STF response is flat. The zeros of the NTF are optimized for maximum quantization noise and poles are placed inside the unit circle. The complete modulator loop filter has four integrators in the loop filter with multiple feedback digital-to-analog converter (DAC) for maximum stability. The complete modulator simulation shows it an achieve signal-to-noise (SNR) of 1.43 dB with oversampling ratio (OSR) of 128.

Characterization of the Attachment of Three New Coliphages onto the Ferrichrome Transporter FhuA.

Receptor-binding proteins (RBPs) allow phages to dock onto their host and initiate infection through the recognition of proteinaceous or saccharidic receptors located on the cell surface. FhuA is the ferrichrome hydroxamate transporter in Escherichia coli and serves as a receptor for the well-characterized phages T1, T5, and phi80. To further characterize how other FhuA-dependent phages attach to FhuA, we isolated and published the genomes of three new FhuA-dependent coliphages: JLBYU37, JLBYU41, and JLBYU60. We identified the egions of FhuA involved in phage attachment by testing the effect of mutant fhuA alleles containing single-loop deletions of extracellular loops (L3, L4, L5, L8, L10, and L11) on phage infectivity. Deletion of loop 8 resulted in complete resistance to SO1-like phages JLBYU37 and JLBYU60 and the previously isolated vB_EcoD_Teewinot phage, but no single-loop deletions significantly altered the infection of T1-like JLBYU41. Additionally, lipopolysaccharide (LPS) truncation coupled with the L5 mutant significantly impaired the infectivity of JLBYU37 and JLBYU60. Moreover, significant reductions in the infectivity of JLBYU41 were observed upon LPS truncation in the L8 mutant strain. Analysis of the evolutionary relationships among FhuA-dependent phage RBPs highlights the conservation of L8 dependence in JLBYU37, JLBYU60, Teewinot, T5, and phi80, but also showcases how positive selective pressure and/or homologous recombination also selected for L4 dependence in T1 and even the lack of complete loop dependence in JLBYU41. IMPORTANCE Phage attachment is the first step of phage infection and plays a role in governing host specificity. Characterizing the interactions taking place between phage tail fibers and bacterial receptors that better equip bacteria to survive within the human body may provide insights to aid the development of phage therapeutics.

DaGzang: a synthetic data generator for cross-domain recommendation services.

Research on cross-domain recommendation systems (CDRS) has shown efficiency by leveraging the overlapping associations between domains in order to generate more encompassing user models and better recommendations. Nonetheless, if there is no dataset belonging to a specific domain, it is a challenge to generate recommendations in CDRS. In addition, finding these overlapping associations in the real world is generally tricky, and it makes its application to actual services hard. Considering these issues, this study aims to present a synthetic data generation platform (called DaGzang) for cross-domain recommendation systems. The DaGzang platform works according to the complete loop, and it consists of the following three steps: (i) detecting the overlap association (data distribution pattern) between the real-world datasets, (ii) generating synthetic datasets based on these overlap associations, and (iii) evaluating the quality of the generated synthetic datasets. The real-world datasets in our experiments were collected from Amazon's e-commercial website. To validate the usefulness of the synthetic datasets generated from DaGzang, we embed these datasets into our cross-domain recommender system, called DakGalBi. We then evaluate the recommendations generated from DakGalBi with collaborative filtering (CF) algorithms, user-based CF, and item-based CF. Mean absolute error (MAE) and root mean square error (RMSE) metrics are measured to evaluate the performance of collaborative filtering (CF) CDRS. In particular, the highest performance of the three recommendation methods is user-based CF when using 10 synthetic datasets generated from DaGzang (0.437 at MAE and 0.465 at RMSE).