Introduction to Still Challenging

What is/are Still Challenging?

Still Challenging - Facial recognition (FR) in unconstrained weather is still challenging and surprisingly ignored by many researchers and practitioners over the past few decades. ^[1] Leveraging on such reference architectures, the automated deployment of distributed toolsets and frameworks on various clouds is still challenging due to the diversity of technologies and protocols. ^[2] The treatment for TMJ inflammation is still challenging due to the rapid clearance and lack of selectivity of traditional medication. ^[3] Despite face alignment has made significant progress, it is still challenging to get a small and accurate face landmark detection model. ^[4] However, the direct intercalation of organic guest molecules into the gallery of LDHs using carbonate-intercalated LDHs as the starting material is still challenging. ^[5] In spite of the good performance of convolutional neural network (CNN) and graph neural network (GNN) in 3D point cloud classification and segmentation at present, to aggregate local information of point clouds and improve the robustness of geometric transformation are still challenging problems. ^[6] The mechanistic understanding of propane conversion to aromatics is still challenging due to the complexity of the aromatization process. ^[7] However, it is still challenging to correctly detect CNVs of different lengths. ^[8] CLINICAL RELEVANCE Management of patients under antiplatelet or anticoagulant drugs is still challenging in clinical practice. ^[9] Background Ovarian cancer seriously threatens the lives and health of women, and early diagnosis and treatment are still challenging. ^[10] However, due to the complex structure and various sizes of ship, detecting multi-scale ships under complex backgrounds is still challenging. ^[11] However, the rapid generation of RFeS for the selective and efficient degradation of EOCs over a wide pH range is still challenging. ^[12] However, primary or secondary resistance to current therapies is still challenging. ^[13] However, how to maximize the benefits and minimize the costs of afforestation is still challenging. ^[14] However, valve technology for nanofluidic control (nanovalves) is still challenging due to the ultrasmall size (100 nm scale) of the nanochannels. ^[15] However, the preparation of high-performance soybean meal-based adhesives was still challenging. ^[16] However, comprehensive analysis of mutational data from MRS is still challenging, necessitating complicated integration of a plethora of computational and statistical approaches. ^[17] The PFASs destruction is still challenging in practice because of the powerful C–F bond and has only been utilized at the laboratory and small scale. ^[18] Among the associated factors of ONFH, majority of patients who require high-dose corticosteroid are still challenging due to inevitable therapeutic option regardless of poor prognosis. ^[19] However, the determination of the key toxicants that consider the combined effects of all sediment-related contaminants are still challenging and necessary for an appropriate sediment risk assessment. ^[20] Understanding the implication of point cloud is still challenging to achieve the goal of classification or segmentation due to the irregular and sparse structure of point cloud. ^[21] However, it is still challenging to modulate the localized surface plasmon resonance (LSPR) of gold nanomaterials from the first near-infrared (NIR-I) to NIR-II region. ^[22] Although convolutional neural networks (CNNs) show great abilities in image classification, improving their performance is still challenging for shallow networks. ^[23] The effect of the natural sources of fructose such as high fructose fruits and honey on the risk of fatty liver is still challenging. ^[24] However, the etching of this material is still challenging. ^[25] The consistent reduction of random background noise to capture functionally meaningful biological signals is still challenging. ^[26] However, designing efficient cryptographically enforced dynamic access control system in the cloud is still challenging. ^[27] It is still challenging to construct stable 3D energy storage materials at the nanoscale by precise pore structure control and reasonable surface modification. ^[28] Nevertheless, it is still challenging to synthesize photochromic materials that selectively absorb different wavelengths of light for erasable optical storage. ^[29] Nevertheless, it is still challenging to efficiently load inorganic nano-antibacterial materials in polymer fibers. ^[30] Cerebral organoids are a promising model to study human brain function and disease, though the high inter-organoid variability of the mini-brains is still challenging. ^[31] However, its practical application is still challenging due to the lack of an appropriate method for its scalable damage-free transfer to a device substrate. ^[32] However, it is still challenging to prepare CTFs with good crystallinity via an efficient approach under mild conditions. ^[33] Vaccination aims at reaching sterilizing immunity, however assessing vaccine efficacy is still challenging and underscores the need for a better understanding of immune protective responses. ^[34] The consequences of the noisy environment are still challenging due to the lack of analytical tools. ^[35] However, the current technological gap between virtual scaffold design and practical AM processes makes it still challenging to realize scaffolds capable of encoding all structural and cell regulatory functions of the native extracellular matrix (ECM) of health and diseased tissues. ^[36] At present, stem cell transplantation has a significant therapeutic effect on spinal cord injury (SCI), however, it is still challenging for the seed cells selection. ^[37] Switchable and perceptive adhesion regardless of the shape or surface shape of the object is still challenging in dry and aquatic surroundings. ^[38] Controlling their lengths in an open-loop based on pressure is still challenging, due to their non-linear nature, even more so if external perturbations can occur. ^[39] Although vanadium (V)-based sulfides have been investigated as cathodes for aqueous zinc-ion batteries (ZIBs), the performance improvement and the intrinsic zinc-ion (Zn2+) storage mechanism revelation is still challenging. ^[40] Viruses that infect bacteria (phages) are increasingly recognized for their importance in diverse ecosystems but identifying and annotating them in large-scale sequence datasets is still challenging. ^[41] However, reconstituting protein-channel complexes in physiological environments is still challenging, limiting our ability to identify tools and probes based on allosteric mechanisms, which could lead to more targeted and precise modulation of the channel function. ^[42] However the formation of global prior from local patch interaction is still challenging for patch-based image denoising methods. ^[43] However, it is still challenging to build the algorithmic mapping from one modality space to another, namely the cross-modal visual-tactile data translation/generation, which could be potentially important for robotic operation. ^[44] However, in China to assess hydrological drought at national scale is still challenging basically because of the difficulty of obtaining runoff data. ^[45] Most existing works have focused on mining high-utility itemsets from databases showing large amount of patterns; however exact decisions are still challenging to make from that large amounts of discovered knowledge. ^[46] However, translating the synthetic lethality targets to the clinics is still challenging due to the complex nature of cancers. ^[47] However, continuous-wave (CW) pumped lasing of 2D lead halide perovskites, as the precondition for the electrically pumped lasing, is still challenging. ^[48] However, it is still challenging to design for sustainable carbon sequestration. ^[49] Although research work has been carried out in the field of MHD flow control at home and abroad, its experimental investigation is still challenging. ^[50]

hydrogen evolution reaction

Rationally designing highly efficient, stable and earth-abundant electrocatalysts plays a leading role for hydrogen evolution reaction (HER) from water splitting but is still challenging. ^[1] Developing stable, efficient and economical electrocatalytic materials is still challenging for hydrogen evolution reaction (HER). ^[2] Developing high-performance electrocatalysts toward hydrogen evolution reaction is important for clean and sustainable hydrogen energy, yet still challenging. ^[3] Rational coupling of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalysts is extremely important for practical overall water splitting, but it is still challenging to construct such bifunctional heterostructures. ^[4] Recently, electrocatalytic N2 reduction to NH3 production has attracted as a potential approach, but achieving high NH3 yield and Faradaic efficiency, and avoiding competitive hydrogen-evolution reaction (HER) are still challenging. ^[5] The development of cost-effective, high-efficiency bifunctional electrocatalysts as alternatives to the state-of-the-art Pt-based materials toward the hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) is of great significance but still challenging. ^[6] The development of palladium-based catalysts for alkaline hydrogen evolution reaction (HER) is highly desired for renewable hydrogen energy systems, yet still challenging due to the strong palladium-hydrogen bond. ^[7] It is highly desirable but still challenging to construct three-dimensional (3D) open porous structure assembled with small-sized and hollow active components for hydrogen evolution reaction (HER). ^[8]

oxygen evolution reaction

Rational construction of advanced bifunctional catalysts with dual-active-sites is still challenging for both oxygen reduction (ORR) and oxygen evolution reactions (OER). ^[1] The oxygen evolution reaction (OER) at anode requires high overpotential and is still challenging. ^[2] The development of highly active and low-cost oxygen evolution reaction (OER) electrocatalysts is pivotal for the efficient generation of renewable hydrogen but still challenging. ^[3] Controllable construction of self-supporting electrodes with efficient charge migration on the whole electrode and abundant electrocatalytic active sites is still challenging in oxygen evolution reaction (OER). ^[4] Developing efficient electrocatalysts for the neutral oxygen evolution reaction (OER) is important but still challenging. ^[5]

long term stability

However, chemical vapor detection is still challenging for organic microlaser sensors, as it requires not only optical gain and self-assembly capability, but also rapid response to stimuli and long-term stability under high excitation power. ^[1] However, their lack of long-term stability and low targetability are still challenging. ^[2] It is still challenging for conductive polymer composite-based electromagnetic interference (EMI) shielding materials to achieve long-term stability while maintaining high EMI shielding effectiveness (EMI SE), especially undergoing external mechanical stimuli, such as scratches or large deformations. ^[3] Organic-inorganic metal halide perovskites are regarded as one of the most promising candidates in the photovoltaic field, but simultaneous realization of high efficiency and long-term stability is still challenging. ^[4]

oxygen reduction reaction

Understanding the origin of the high electrocatalytic activity of Fe–N–C electrocatalysts for oxygen reduction reaction is critical but still challenging for developing efficient sustainable nonprecious metal catalysts used in fuel cells. ^[1] Reasonable design of the porous metal-organic frameworks (MOFs) to convert a burgeoning carbon-based catalysts with high oxygen reduction reaction (ORR) activity are still challenging in energy conversion, storage and transport. ^[2] It is intriguing but still challenging to develop non-noble electrocatalysts with efficient catalytic centers to replace Pt-based ones for oxygen reduction reaction (ORR) in both alkaline and acidic conditions. ^[3] Understanding the origin of high activity of Fe-N-C electrocatalysts in oxygen reduction reaction (ORR) is critical but still challenging for developing efficient nonprecious metal catalysts in fuel cells and metal-air batteries. ^[4]

optical remote sensing

Currently, reliable and accurate ship detection in optical remote sensing images is still challenging. ^[1] At present, reliable and precise ship detection in high-resolution optical remote sensing images affected by wave clutter, thin clouds, and islands under complex sea conditions is still challenging. ^[2] Although considerable success has been achieved in change detection on optical remote sensing images, accurate detection of specific changes is still challenging. ^[3]

attracted increasing attention

The design and synthesis of highly dispersed metal catalyst have attracted increasing attention, and it is still challenging to generate stable metal clusters with high metal loadings. ^[1] The coexistence of multiferroic orders has attracted increasing attention for its potential applications in multiple-state memory, switches, and computing, but it is still challenging to design single-phase crystalline materials hosting multiferroic orders at above room temperature. ^[2] Non-precious transition-metal based materials have attracted increasing attention as an efficient oxygen electrocatalysts for Zn-air battery although their unsatisfactory durability in harsh charging/discharging cycling condition makes their practical application still challenging. ^[3]

specific surface area

However, synthesis of ultra-high specific surface area mesoporous silica nanoparticles with well-defined sphere structure and small particle size (< 200 nm) is still challenging. ^[1] Surface cracks could improve the optical and photoelectronic properties of crystalline materials due to the increased specific surface area, but controlled self-assembly of fullerene (C60) molecules into micro-/nanostructures with surface cracks is still challenging. ^[2] It is desirable but still challenging to optimize meso-/micro-pore ratio and configuration while achieving a high specific surface area in carbon nanofibers. ^[3]

Yet Still Challenging

Attaining an energy-efficient pathway to switch the rotation of polarization vortex with the use of trivial homogeneous electric field is essentially important for low-power consumption electronic nanodevices, yet still challenging. ^[1] Developing a reliable strategy for the modulation of the texture, composition, and electronic structure of electrocatalyst surfaces is crucial for electrocatalytic performance, yet still challenging. ^[2] Developing high-performance electrocatalysts toward hydrogen evolution reaction is important for clean and sustainable hydrogen energy, yet still challenging. ^[3] Developing highly efficient anodic catalyst is important, yet still challenging. ^[4] Development of advanced oil/water separation materials with durability, versatility, and cost-efficiency in a green manner is highly desired yet still challenging. ^[5] However, the large-scale preparation of low cost photothermal materials for solar steam generators is highly desired yet still challenging. ^[6] The development of palladium-based catalysts for alkaline hydrogen evolution reaction (HER) is highly desired for renewable hydrogen energy systems, yet still challenging due to the strong palladium-hydrogen bond. ^[7]

Remain Still Challenging

Because of its harsh growth requirements, limited detection methods, and non-specific clinical manifestations, diagnosing Legionella pneumonia remains still challenging. ^[1] However, careful size tuning in such a regime remains still challenging. ^[2] However, flood susceptibility prediction in data-scarce regions remains still challenging. ^[3] Although, their therapeutic management remains still challenging. ^[4] In this context, for applications like concrete rebars assessments, utility networks surveys, the precise localization of embedded cylindrical pipes remains still challenging due to complex geometrical and dielectric characteristics of the stratified medium. ^[5]

Task Still Challenging

In industry, defect detection involves two kinds of tasks: defect classification and location, which make it difficult to ensure the accuracy of both, and also make the task still challenging in practical application. ^[1] However, relational facts in these texts are often complicated, where most of them contain overlapping triplets, making the joint extraction task still challenging. ^[2]

still challenging issue

However, high sensitivity and good selectivity are still challenging issues blocking their further development. ^[1] There are several techniques have been proposed for quality assessment but the accurate feature learning is still challenging issues in various image processing applications. ^[2] Despite the remarkable advances in terms of salt adsorption capacity (SAC) and charge efficiency (QE), there are still challenging issues concerning the electrode stability for long‐term operation. ^[3] Controlling chondroitin sulfates (CSs) biological functions to exploit their interesting potential biomedical applications requires a comprehensive understanding of how the specific sulfate distribution along the polysaccharide backbone can impact in their biological activities, a still challenging issue. ^[4] However, needs of additional actuations, eccentric properties for a specific situation and complicated fabrications, with only a few reports to date, show that multispectral (visible and IR) camouflage surfaces are still challenging issues. ^[5] Concrete is a typical quasi-brittle material, and the nonlinear analysis and crack simulation of concrete during loading are still challenging issues. ^[6] This macroscopic model obviously overperforms CFDs regarding computational cost; however, determining its coefficients is a still challenging issue. ^[7] Thus, there are still challenging issues of current ultrasound imaging (USI) systems, such as low-quality ultrasound images, slow time response to emergencies, and location-based operation. ^[8] Thermal treatment of plastic waste into fuels has gained substantial prominence in the scientific community, but processing of municipal mixed plastic waste (MMPW) has still challenging issues due to the wide variance in plastic composition, size, decomposition behavior, and thermal behavior. ^[9] Deformation mechanisms and microstructural evolution are still challenging issues. ^[10] Diamond/SiC composites with high thermal conductivity are important materials for electronic industry, especially electronic packaging, but their complex structures and high-precision manufacturing are still challenging issues. ^[11] — Even though, reconfigurable intelligent surfaces (RISs) are adopted in various scenarios to enable the implementation of a smart radio environment, there are still challenging issues for its real-time operation due to the need for a costly full dimensional channel estimation with offline exhaustive search or online exhaustive beamtraining. ^[12]

still challenging task

However, P waves detection is a still challenging task, especially in long-term ECGs with manifested cardiac pathologies. ^[1] Image restoration is still challenging task to recover an original image using a degradation and restoration model. ^[2] However, rapid and accurate identification of the cancer cell pattern from the cell biopsy is still challenging task. ^[3] Thus, detecting crimes is a still challenging task. ^[4] However, how to segment medical images accurately and how to build neural network effectively with very limited computing resource, is still challenging task. ^[5] However, achieving an accurate crowd counting and generating a precise density map are still challenging tasks due to the occlusion, perspective distortion, complex backgrounds, and varying scales. ^[6] Accurate fast hand detection and gesture recognition for hand understanding are still challenging tasks that are influenced by the diversity of hands and the complexity of the scene in color images. ^[7] Accurate intrusion detection is still challenging task in terms of improving security and intrusion detection rate. ^[8] Background: Automatic detection and classification of breast masses in mammograms are still challenging tasks. ^[9] Developing efficient and low-cost urea oxidation reaction (UOR) catalysts is a promising but still challenging task for environment and energy conversion technologies such as wastewater remediation and urea electrolysis. ^[10] Timely finding and interpreting genetic variants are still challenging tasks among diagnostic laboratories and clinicians. ^[11] Moreover, there are still challenging tasks for Deep Networks: contexts where the success depends on structured knowledge that can not be easily provided to the networks in a standardized way. ^[12]

still challenging problem

In spite of the good performance of convolutional neural network (CNN) and graph neural network (GNN) in 3D point cloud classification and segmentation at present, to aggregate local information of point clouds and improve the robustness of geometric transformation are still challenging problems. ^[1] Under the influence of atmospheric turbulence, there are still challenging problems in the OAM multiplexing system. ^[2] However, the localization accuracy and robustness are still challenging problems due to low-cost noisy devices, especially in those complicated localization environments. ^[3] However, due to complex backgrounds, ambiguous boundaries, heterogeneous appearances and highly varied shapes of the liver, accurate liver segmentation and tumor detection are still challenging problems. ^[4] Efficient assessment of small first-passage failure probabilities of nonlinear structures with uncertain parameters under stochastic seismic excitations is an important but still challenging problem. ^[5] Given the complex nature of human brain signals, emotion recognition and regulation are still challenging problems. ^[6] However, motion learning and generalization of musculoskeletal systems are still challenging problems. ^[7] However, the inherent chattering and none finite-time convergence are still challenging problems in SMO application. ^[8] In self-supervised monocular depth estimation, the depth discontinuity and motion objects' artifacts are still challenging problems. ^[9] Partially removing the framework Al atoms from low-silica aluminosilicates is an old but still challenging problem, because a high framework Al content generally induces lower acid strength and fast deactivation. ^[10] Conclusion Severe hyperbilirubinemia requiring exchange transfusion and acute bilirubin encephalopathy are still challenging problems in neonatal periodin our country. ^[11]

still challenging since

However, their design is still challenging since it should account for their entire lifetime, from rapid cycling exploitation to centuries of abandonment. ^[1] Currently this is still challenging since typical methods rely on MR-images, and are therefore limited by the 3D MR-imaging latency. ^[2] However, its design is still challenging since most of existing hydrogel adhesive cannot work in wet environments. ^[3] However, it is still challenging since the feature information in the vibration signal is usually submerged by strong and complex noise. ^[4] Faulty feeder detection of single phase-earth fault for medium voltage distribution networks is still challenging since the weak fault feature and diverse fault conditions. ^[5] Elemental mercury (Hg0) removal from a hot gas is still challenging since high temperature influences the Hg0 removal and regenerable performance of the sorbent. ^[6] Nevertheless, the rapid prototyping of such actuators is still challenging since conventional 3D printers are not designed to fabricate airtight objects or to specify their bending behavior by combining materials of different stiffness. ^[7] Nevertheless, establishing EUS as a firm diagnostic and therapeutic modality is still challenging since the performance of interventional EUS requires high expertise and adequate facilities. ^[8] However, accurate decoding is still challenging since fMRI data acquired from only a single subject have several disadvantageous characteristics such as small sample size, noisy nature, and high dimensionality. ^[9] But the distinctive detection of these two ions is still challenging since they belong to the same periodic group and have similar chemical properties. ^[10]

still challenging owing

Despite significant progress in object detection tasks, remote sensing image target detection is still challenging owing to complex backgrounds, large differences in target sizes, and uneven distribution of rotating objects. ^[1] However, its widespread utilization is still challenging owing to the inherent requirement of a high electric current density for efficient magnetization switching. ^[2] Accurate measurements on physiological parameters using wearable monitoring devices during physical exercises are essential for personal healthcare and rehabilitation training, but still challenging owing to various motion artifacts (MA) caused by the interfacial dynamic change between wearable sensors and human skin. ^[3] Although a wide range of thermoplastic polymers are available as 3DP feedstock, yet obtaining biocompatible and structurally integrated biomedical devices is still challenging owing to various technical issues. ^[4] However, fabricating SACs with high atomic dispersion is still challenging owing to their extremely high surface energy. ^[5] Although a nodule detection method based on deep learning has achieved good performance, building a nodular detection network with good generalization performance is still challenging owing to the unbalanced positive and negative samples. ^[6] The real-time monitoring of NO in the low-concentration range from the ppb- to ppm-level is of great importance in the field of healthcare; however, accomplishing this is still challenging owing to the technical issues regarding highly efficient and selective sensing materials. ^[7] Although many different imaging modalities are in use today, molecular imaging with computed tomography (CT) is still challenging owing to its low sensitivity and soft tissue contrast compared with other modalities. ^[8]

still challenging even

However, robot coordination and task allocation to a correct mission accomplishment are still challenging even with technological advances. ^[1] Mapping highly dynamic cropping systems using satellite image time series is still challenging even when robust approaches are used. ^[2] The management of inverted papilloma involving frontal sinus and supraorbital ethmoidal cells is still challenging even for the well-trained rhinologists. ^[3] However, not all speaking styles are easy to model: highly expressive voices are still challenging even to recent TTS architectures since there seems to be a trade-off between expressiveness in a generated audio and its signal quality. ^[4] Blind assessment of video quality is still challenging even in this deep learning era. ^[5]

still challenging especially

However, use of the DOAC as an initial treatment for CA-PVT appears still challenging especially in the early postoperative period after major surgery in terms of unestablished efficacy and safety in such occasion. ^[1] However, the regio-chemistry control to access all the possible results is still challenging especially for the reaction involving multiple addition steps. ^[2] Conclusion: The diagnosis of CPE is still challenging especially for difficulties in isolating microorganisms. ^[3]

still challenging regarding

However, human–robot physical interactions are still challenging regarding maneuverability, controllability, stability, drive layout, and autonomy. ^[1] Due to the widespread use of pesticides and their harmful effects on humans and wildlife, monitoring their residual amounts in crops is critically essential but still challenging regarding the development of high-throughput approaches. ^[2] However, the creation of defenseless gadgets still challenging regarding the restriction of involved assets especially with the attackers ‘continuous trials to misuse these restrictions chasing important information. ^[3]

still challenging today

The CPP for link failures is still challenging today. ^[1] Indexing large-scale databases in main memory is still challenging today. ^[2] Treatment of fusiform basilar artery aneurysms is still challenging today. ^[3]

still challenging nowaday

Encapsulating and storing hydrophilic payloads are still challenging nowadays. ^[1] Although results of adoptive cell therapies are very promising, obtaining large batches of T cell at clinical scale is still challenging nowadays. ^[2] Achieving CO oxidation at room temperature is significant for gas purification but still challenging nowadays. ^[3]

still challenging considering

However, specific activation at the cellular level is still challenging considering the macroscopic-scale exposure area of usual light sources. ^[1] Although the disease classification, diagnosis and targeted therapy of RCC has been increasingly evolving attributing to the rapid development of current molecular pathology, the current clinical treatment situation is still challenging considering the comprehensive and progressively developing nature of malignant cancer. ^[2] However, this work is still challenging considering the complex temporal and spatial dependence between network traffic. ^[3]

still challenging mainly

Diffuse optical tomography (DOT) offers the potential to diagnose FTC because it can measure tumor hypoxia, while image reconstruction of the thyroid is still challenging mainly due to the complex anatomical features of the neck. ^[1] However, this task is still challenging mainly due to the serious occlusion in crowds and large appearance variations caused by the viewing angles of cameras. ^[2] However, the detection of metastases in hematoxylin and eosin (H&E) stained whole-slide images (WSI) is still challenging mainly due to two aspects. ^[3]

still challenging aspect

However, a wide range of battery voltage levels and fast response to power conversion between forward and backward operations are still challenging aspects of the aging test power system. ^[1] , are still challenging aspects to modern biomedical research. ^[2]

still challenging requiring

4 Gy and chemotherapy with Mitomycin C and 5FU) heals patients with anal cancer in up to 85%, salvage surgery in residual or recurrent anal cancer is still challenging requiring at least abdominoperineal excision (APE) leaving an extensive tissue defect in an irradiated area with demand for reconstructive surgery. ^[1] Within the last decades, different modalities were used to assess severity and outcome including Glasgow Coma Scale (GCS), imaging modalities, and even genetic polymorphism, however, determining the prognosis of TBI victims is still challenging requiring the emerging of more accurate and more applicable tools to surrogate other old modalities. ^[2]