Smooth Index Research Articles

Optimal design of broadband, low-directivity graded index acoustic lenses for underwater communication.

Manipulating underwater pressure waves is crucial for marine exploration, as electromagnetic signals are strongly absorbed in water. However, the multi-path phenomenon complicates the accurate capture of acoustic waves by receivers. Although graded index lenses, based on metamaterials with smoothly varying properties, successfully focus pressure waves, they tend to have high directivity, which hinders practical application. This work introduces three 2D acoustic lenses made from a metamaterial composed of solid inclusions in water. We propose an optimization scheme where the pressure dynamics is governed by Helmholtz's equation, with control parameters affecting each lens cell's density and bulk modulus. Through an appropriate cost function, the optimization encourages a broadband, low-directivity lens. The large-scale optimization is solved using the Lagrangian approach, which provides an analytical expression for the cost gradient. This scheme avoids the need for a separate discretization step, allowing the design to transition directly from the desired smooth refractive index to a practical lattice structure. As a result, the optimized lens closely aligns with real-world behavior. The homogenized numerical model is validated against finite elements, which considers acoustic-elastic coupling at the microstructure level. When homogenization holds, this approach proves to be an effective design tool for achieving broadband, low-directivity acoustic lenses.

Three-Dimensional Model-Based Line-of-Sight Analysis for Optimal Installation of IoT Monitoring Devices in Underground Mines

Internet of things (IoT)-based wireless communication technology has been applied for efficient work and safety in mines. However, underground mines are surrounded by walls and have numerous curves, which reduce communication stability. For smooth communication between devices, a line of sight (LOS) must be connected without obstacles. If optimal installation locations in a virtual space can be confirmed before installing the device in the field, trial and error can be avoided. In this study, a 3D model-based LOS analysis technology was developed using Python and a ray-casting algorithm. A place with numerous LOS connections has good communication with other places; consequently, it is a suitable location to install the device. To indicate the degree of communication smoothness, a smooth communication index was proposed. A preliminary experiment was conducted in an indoor space within the Samcheok Campus of the Kangwon National University, and a field experiment was conducted at the Samdo Mine in Dogye-eup, Samcheok-si, Gangwon-do. Based on these results, an effective wireless sensor network (WSN) was established by installing a ZigBee-based monitoring device. The results of this study can be further improved and used for constructing smooth WSNs in underground mines in the future.

Calf circumference predicts sarcopenia in maintenance hemodialysis.

Early recognition of sarcopenia in hemodialysis (HD) patients will be of great importance in preventing adverse outcomes and improving the quality of life in these patients. The main goal of this study was to evaluate the diagnostic accuracy of calf circumference (CC) measurement in detecting sarcopenia among CKD patients undergoing maintenance HD. This cross-sectional study included 52 patients (53 ± 17 years) who were currently in a maintenance HD. Muscle strength was evaluated using handgrip strength, and smooth muscle mass index (SMI) was assessed through bioelectrical impedance analysis, and CC was measured at the widest part of the calf with the foot pressed against a hard surface. Out of the total patient population, sarcopenia was identified in 32.7% (n = 17). The two groups were comparable in terms of age, weight, and height, but the median body mass index of sarcopenic group was statistically lower than nonsarcopenic group (21.6 kg/m2 [18.9-24.6] vs 24.7 kg/m2 [21.4-27.3]. The sarcopenic group had a substantially smaller CC than the nonsarcopenic group (30.0 cm [26.5-32.0] vs 31.5 cm [30.3-34.8], P = 0.013; respectively). In the regression analysis, CC was found to be independently associated with post-HD SMI (P < 0.001; odds ratio, 1.938; and 95% CI, 1.020-2.856). CC was positively but weakly correlated with handgrip strength, however strong and significant correlation was found between CC and SMI (r = 0.277, P = 0.047 and r = 0.733, P < 0.001; respectively). A CC of 31 cm or less predicted confirmed sarcopenia in HD patients (area under the curve = 0.709, P = 0.006, specificity = 0.556, sensitivity = 0.765). Low muscle mass and potentially low muscle strength in HD patients can be accurately identified through the use of CC measurements. Specifically, a CC measurement below 31 cm has found to be a useful indicator to identify individuals on maintenance HD.

Comparison Between the Clinical Effect of Percutaneous Kyphoplasty for Osteoporosis Vertebral Compression Fracture Patient with or Without Sarcopenia: A Retrospective Cohort Study.

Sarcopenia and osteoporosis vertebral compression fractures (OVCF) are common diseases that increase with age. This study aimed to investigate the effects of sarcopenia on OVCF patients after percutaneous kyphoplasty (PKP). Data of 101 patients who were treated with single-level PKP between January 2021 and March 2022 at Ningbo No.6 Hospital were enrolled. Forty-five OVCF patients with sarcopenia who met our inclusion criteria were included in the Sarcopenia-PKP group (SPKP group), and 56 patients in the Normal-PKP group (NPKP group). All clinical and radiological data were collected from medical records. Baseline characteristics, operation-related parameters (operation time, time to ambulation, hospital stay, surgery segment), clinical outcomes (visual analog score [VAS], Oswestry Disability Index [ODI], Japanese Orthopaedic Association Scores [JOA] of lumber), radiological outcomes (vertebral anterior height rate and local kyphosis angle), Macnab score, and complications were evaluated and compared. There were no significant differences in age, sex, surgical segment preoperative VAS score, ODI, or JOA between the two groups (P > 0.05). The SPKP group had a significantly lower body mass index (BMI), bone mineral density (BMD), and smooth muscle index (SMI) than the NPKP group (P < 0.05). Significantly longer hospital stays and time to ambulation in SPKP group than NPKP group (3.7±0.8 vs 3.4±0.5 and 2.0±0.8 vs 1.6±0.5, P < 0.05). In SPKP group, significantly better clinical outcomes at 6- and 12-months follow-up were observed in NPKP group than SPKP group (P < 0.05), and NPKP group showed significantly better in vertebral anterior height rates than SPKP group after 6-month follow-up (P < 0.05). Moreover, there were significantly more cases of complications in the SPKP group (P < 0.05). Sarcopenia could reduce the clinical effect of percutaneous kyphoplasty, and furthermore. Related studies are needed to verify the effect of sarcopenia on OVCF patients.

Evaluation of Reliability Parameters of a Cement Manufacturing Plant by using Supplementary Variable Technique

In particular, Article 40 of Law Number 37 of 2004 concerning Bankruptcy and PKPU regulates that the curator may not take an inheritance during bankruptcy that descends to the bankrupt debtor unless it benefits the bankrupt assets. This piece specifically warns the curator not to become a bankrupt banker by being cautious when collecting the debtor's assets. In reality, it is not unusual for the debtor's heirs to decline to provide security for the seizure of the deceased debtor's assets to be used as collateral for repayment of the debt by the creditor. This refusal increases the weight of losses on unresolved/unsettled receivables for creditors as a result of the debtor's passing. Naturally, this raises issues with the legal elements of warranties and contract law. There are rights and responsibilities that cannot be resolved, and it is still unclear how the heirs of a deceased debtor who still owes money to creditors will be treated. The emphasis of this study is on the distinction between the bankruptcy-related positions of the debtor who receives an inheritance (the debtor) and the debtor who inherits it. The mechanism for listing debtor's assets as bankruptcy assets is the second study's main focus. Keywords: Line Balancing, Moodie Young, Line Efficiency, Balance Delay, Smooth Index

The Analysis of Production Line Balance Using the Moodie Young Method at X Inc.

The goal of this study is to determine how much the level of efficiency the production line at PT. X by using the Moodie young approach. The three components of the method - Line Efficiency, Balance Delay, and Smooth Index - are utilized to assess the degree of balance in the manufacturing line. The findings indicated that there were 5 work stations with 7 work elements in the real production line configuration, with a Line Efficiency of 40.29%, a Balance Delay of 59.70%, and a Smoothness Index of 9578.22. As a consequence of the research utilizing the Moodie Young approach, the new production lines are composed of 3 work stations with 7 work elements and a Line Efficiency result of 67.15%, Balance Delay of 32.84%, and Smoothness Index of 4449.71. Keywords: Line Balancing, Moodie Young, Line Efficiency, Balance Delay, Smooth Index

Research on Position Control of an Electro–Hydraulic Servo Closed Pump Control System

A control strategy combining adaptive backstep sliding mode control and dead-zone inverse compensation control in a series was proposed to solve the problem of system parameter uncertainty and system dead-zone in the process of position control in an electro–hydraulic servo closed pump control system. Firstly, an adaptive backstepping sliding mode controller was designed by introducing the sliding mode control principle. Secondly, the smooth dead-zone inverse function was constructed by using the smooth continuous index function to design the dead-zone inverse compensation controller, which is combined with the adaptive sliding mode controller to form a series controller. Finally, the feasibility of the controller was verified by using the pump control servo system of a lithium battery pole strip mill. The experimental results show that, compared with traditional PID control, the control strategy displayed no excessive overshoot before the steady state, the steady-state control accuracy could reach ±0.002 mm, and the time required to reach the steady state was 1 s to 2 s shorter, which shows this method’s ability to effectively improve the position control accuracy of the pump control system, as well as its dynamic response performance.

Iridian anterior segment OCT in rubella uveitis syndrome and cytomegalovirus anterior uveitis: a comparative study.

To compare iris affectation in cytomegalovirus anterior uveitis (CMVAU), rubella virus-associated uveitis (RVU), and healthy contralateral eyes, using swept-source anterior segment optical coherence tomography (SS-AS-OCT). A comparative, transversal, retrospective study examining 60 eyes from 30 patients-18 eyes (17 patients) with CMVAU, 14 eyes (13 patients) with RVU, and 28 healthy eyes-was performed. Six-millimeter cross-sectional SS-AS-OCT B-scans were obtained in each iris quadrant. Images were exported to ImageJ®. Qualitative and quantitative analyses were done: stromal thickness (ST), smooth index (SI), and optical density (OD) of pigment epithelium. Comparisons between measurements and clinical-demographic parameters were performed using SPSS®. Qualitative analysis showed extensive damage in iris stroma but was unable to differentiate between both uveitis. RVU eyes had a lower mean ST (315.72μm ± 42.4) compared to those with CMVAU (348.6μm ± 46) (p = 0.047) and a lower ST in the upper (338.9μm ± 38.52)/(386.25μm ± 47.2) (p = 0.005) and temporal (281.5μm ± 57.3)/(326.43μm ± 62.3) (p = 0.016) quadrants. Mean (0.94 ± 0.02)/(0.9 ± 0.03) (p = 0.001), temporal (0.94 ± 0.02)/(0.89 ± 0.03) (p < 0.001), and nasal SI (0.094 ± 0.02)/(0.9 ± 0.04) (p = 0.005) were higher in RVU. OD was similar in both uveitis. In healthy eyes, mean ST (376.8μm ± 39.7) was higher and mean SI was lower (0.87 ± 0.04) than in RVU (p < 0.001) and CMVAU eyes (p = 0.032). Mean OD was higher in healthy eyes (911 ± 130) than in CMVAU eyes (800 ± 200) (p = 0.037). The quantitative analysis of the SS-AS-OCT iris images allows for the differentiation between healthy eyes and those with CMVAU and RVU, as well as between both uveitis.

High refractive index change in Type A laser modification using a multi-scan approach

The focusing of femtosecond laser pulses is an efficient and robust way to fabricate integrated optical components in glasses. However, the induced refractive index changes are weak if compared with those obtained in lithography. Several solutions have been found to overcome such problem, the multi-scan technique being one of these. The present work implements the multi-scan approach on the femtosecond inscription of Type A laser modifications in high repetition rate regime. Therefore, a study on the effects of the absorption of subsequent laser pulses on the increase of the induced refractive index is conducted. As a result, the achievement of high and smooth refractive index change, up to 2 × 10−2, in a commercial silver-glass is reported. Moreover, such high and controlled index contrast is exploited for the fabrication of low-propagation-losses and engineered waveguides exhibiting single-mode operation in the VIS-NIR range.

Rank-Based Greedy Model Averaging for High-Dimensional Survival Data

ABSTRACT Model averaging is an effective way to enhance prediction accuracy. However, most previous works focus on low-dimensional settings with completely observed responses. To attain an accurate prediction for the risk effect of survival data with high-dimensional predictors, we propose a novel method: rank-based greedy (RG) model averaging. Specifically, adopting the transformation model with splitting predictors as working models, we doubly use the smooth concordance index function to derive the candidate predictions and optimal model weights. The final prediction is achieved by weighted averaging all the candidates. Our approach is flexible, computationally efficient, and robust against model misspecification, as it neither requires the correctness of a joint model nor involves the estimation of the transformation function. We further adopt the greedy algorithm for high dimensions. Theoretically, we derive an asymptotic error bound for the optimal weights under some mild conditions. In addition, the summation of weights assigned to the correct candidate submodels is proven to approach one in probability when there are correct models included among the candidate submodels. Extensive numerical studies are carried out using both simulated and real datasets to show the proposed approach’s robust performance compared to the existing regularization approaches. Supplementary materials for this article are available online.

Fault Feature Extraction of Automobile Wheel Hub Bearing Based on RSK and RSSD

Abstract Wheel hub bearing not only bears axial load but also radial load, and then its running status directly affects the performance and safety of the automobile. In particular, complicated and variable driving conditions of the automobile are not only liable to aggravate the occurrence of mechanical fault such as localized wear, but also often cause powerful intermittent interference noise. It is difficult to extract the vibration characteristics of the transient impact and harmonic components of the wheel bearings in the event of a local fault. An extraction method of fault feature based on ration of smooth and kurtosis (RSK) index and resonance-based signal sparse de-composition (RSSD) is proposed for automobile wheel hub bearings, which aims at the minimum value of RSK index, sequentially optimizes the Q-factor of the resonance sparse decomposition, and obtains its optimal value adaptively to achieve the decomposition of low resonance components with transient impact components and high resonance components with harmonic components. The effect of the method has been verified by powerful intermittent interference simulation signals and experiment signals from local fault of wheel hub bearing with periodic dynamic radial loading.

Nutritional Status Impairment Due to Neoadjuvant Chemotherapy Predicts Post-Radical Cystectomy Complications.

Background: Radical cystectomy (RC) is the standard treatment for muscle invasive bladder cancer (MIBC). Neoadjuvant chemotherapy (NAC) is associated with improved patient survival. The impact of NAC on nutritional status is understudied, while the association between malnutrition and poor surgical outcomes is well known. This study aims to examine the association between NAC, nutritional status impairment, and post-operative morbidity. Materials and Methods: We included MIBC patients who underwent RC and received NAC from multiple academic centers in Israel. Cross-sectional imaging was used to measure the psoas muscle area and normalized it by height (smooth muscle index, SMI). Pre- and post-NAC SMI difference was calculated (represents nutritional status change). The primary outcomes were post-RC ileus, infection, and a composite outcome of any complication. Logistic regression models were fit to identify independent predictors of the outcomes. Results: Ninety-one patients were included in the study. The median SMI change was −0.71 (−1.58, −0.06) cm2/m2. SMI decline was significantly higher in patients with post-RC complications (−18 vs. −203, p < 0.001). SMI change was an independent predictor of all complications, ileus, infection, and other complications. The accuracy of SMI change for predicting all complications, ileus, infection, and other complications was 0.85, 0.87, 0.75, and 0.86, respectively. Conclusions: NAC-related nutritional deterioration is associated with increased risk of complications after RC. Our results hint towards the need for nutritional intervention during NAC prior to RC.

The beneficial effect of physical activity on cognitive function in community-dwelling older persons with locomotive syndrome

BackgroundCognitive decline is closely related to motor decline. Locomotive syndrome (LS) is defined as a state associated with a high risk of requiring support because of locomotive organ disorders, and can be evaluated using a questionnaire. This study aimed to clarify the effectiveness of daily goal-targeted exercise on cognitive function in two different populations classified by scores on the Locomo 25 questionnaire.MethodsSeventy community-dwelling older people who participated in a 13-week health class were divided into two populations based on Locomo 25 scores: <7 (non-LS) and ≥7 (LS). Participants were presented with a daily target steps and worked towards that goal. Cognitive function was evaluated using the Japanese version of Addenbrooke’s Cognitive Examination-Revised (ACE-R). Average daily physical activity (exercise [Ex]) for 13 weeks was measured using a portable activity meter. Depression status was assessed using the Geriatric Depression Scale (GDS-15).ResultsNo significant differences were observed in age, years of education, body mass index, smooth muscle mass index, GDS-15 scores, or ACE-R scores between the non-LS and LS populations. Multiple logistic regression analysis showed that Ex (odds ratio = 5.01, p = 0.002) for 13 weeks was significantly associated with increased cognitive function in the LS population. The Ex threshold for the increase in cognitive function based on receiver operating curve analysis was 2.29 metabolic equivalents of task (METs) × h (METs · h/day) (p = 0.047) in the LS population. After 13 weeks, ACE-R scores were significantly higher in the Ex ≥ 2.29 than in the Ex < 2.29 METs · h/day group (p = 0.024, ηp2 = 0.241) in the LS population based on two-way analysis of covariance. Furthermore, a significant increase in the ACE-R memory domain was seen in the Ex ≥ 2.29 group (p = 0.035, ηp2 = 0.213).ConclusionsThese results suggest that Ex ≥ 2.29 METs · h/day is important for improving cognitive function in LS populations.

Anti-reflection subwavelength gratings for InP-based waveguide facets

We demonstrate the anti-reflection properties of lithographically defined subwavelength gratings applied to the facets of integrated waveguides realized in the InP membrane-on-silicon platform. The subwavelength gratings are based on the gradient index effect to create a smooth index transition between the core material and air, making it possible to obtain reflections below -30dB at a wavelength of 1550 nm for both TE and TM polarized modes, as shown by 3D finite-difference time-domain simulations. Characterizations performed using Mach-Zehnder interferometers as test structures show relative reflections as low as -25dB, confirming the effectiveness of the technique.

Underwater image enhancement and marine snow removal for fishery based on integrated dual-channel neural network

Computer vision technology can reduce the intensity and difficulty of marine aquaculture. Nonetheless, the degradation problems of marine fishery underwater images hamper further interpretation and analysis of underwater information by computer vision technology. In order to comprehensively solve the problems of degradation in marine fishery underwater images, this paper proposes an end-to-end integrated dual-channel network model, which uses the underwater image enhancement module based on the residual dense network to perform color correction and dehazing for the low-frequency layer of images, and the marine snow removal module based on local residual learning strategy to remove the white marine snow in the high-frequency layer of images. Moreover, the addition of refinement module further improves the textual details and colors of images. Experimental results on marine fishery dataset indicate that the approach proposed in this paper performs better than several state-of-the-art methods in quantitative metrics, including underwater image quality measure (UIQM), blur index and smooth index, effective in improving the contrast of underwater fishery images and reducing marine snow noise, while achieving better visual quality in qualitative evaluation such as color correction, dehazing, detail and feature restoration. Furthermore, the generalization tests and application tests have proved its effectiveness in underwater scenarios, which means it can meet the practical needs in the field of marine aquaculture.

Damage detection in structures using modal curvatures gapped smoothing method and deep learning

This paper deals with damage detection using a Gapped Smoothing Method (GSM) combined with deep learning. Convolutional Neural Network (CNN) is a model of deep learning. CNN has an input layer, an output layer, and a number of hidden layers that consist of convolutional layers. The input layer is a tensor with shape (number of images) × (image width) × (image height) × (image depth). An activation function is applied each time to this tensor passing through a hidden layer and the last layer is the fully connected layer. After the fully connected layer, the output layer, which is the final layer, is predicted by CNN. In this paper, a complete machine learning system is introduced. The training data was taken from a Finite Element (FE) model. The input images are the contour plots of curvature gapped smooth damage index. A free-free beam is used as a case study. In the first step, the FE model of the beam was used to generate data. The collected data were then divided into two parts, i.e. 70% for training and 30% for validation. In the second step, the proposed CNN was trained using training data and then validated using available data. Furthermore, a vibration experiment on steel damaged beam in free-free support condition was carried out in the laboratory to test the method. A total number of 15 accelerometers were set up to measure the mode shapes and calculate the curvature gapped smooth of the damaged beam. Two scenarios were introduced with different severities of the damage. The results showed that the trained CNN was successful in detecting the location as well as the severity of the damage in the experimental damaged beam.

Global exponential stabilization of nonlinear systems via width time-dependent periodically intermittent smooth control

In this paper, the global exponential stability and stabilization problems for a class of nonlinear systems are investigated. Some sufficient conditions to guarantee global exponential stable and estimate the minimum admissible value of the control width are presented in virtue of time-dependent width Lyapunov functions. Furthermore, a periodically intermittent smooth controller with variant control width is introduced and theoretical analysis is provided. The smooth index function of periodically intermittent smooth control inputs is defined and the supremum (or least upper bound) of smooth index function set can be solved. On the basis of the analysis, the designed periodically intermittent smooth controller not only can globally exponentially stabilize the nonlinear systems, but also can control the exponential convergence rate of the nonlinear systems. Finally, numerical simulations are given to verify the obtained theoretical results.

An energy conservative hp-scheme for light propagation using Liouville’s equation for geometrical optics

In this contribution an alternative method to standard forward ray-tracing is briefly outlined. The method is based on a phase-space description of light propagating through an optical system. The propagation of light rays are governed by Hamilton’s equations. Conservation of energy and étendue for a beam of light, allow us to derive a Liouville’s equation for the energy propagation through an optical system. Liouville’s equation is solved numerically using an hp-adaptive scheme, which for a smooth refractive index field is energy conservative. A proper treatment of optical interfaces ensures that the scheme is energy conservative over the full domain.

Characteristics of 1064 nm picosecond laser induced filamentary tracks and damages in sapphire

The induction of structural modifications by focused laser pulses in bulk transparent materials is a versatile technique for the microfabrication of photonic devices. In this paper, the influence of repetition rate, pulse energy and number of pulses was studied by comparing picosecond laser induced structural modifications in sapphire. The observed structural modifications consisted of a uniaxial void zone surrounded by smooth refractive index changes, and micro cracks followed by a submicrometer filamentary track. The number of laser pulses was found to be the primary factor in causing cracks surrounding the focal volume while pulse repetition rate and pulse energy were observed to have minor roles in these cracks. However, with increasing repetition rate, length of the filamentary track decreased, whereas no significant difference was observed in the length by changing number of pulses. Furthermore, filamentary track length has increased with the increase of laser energy. At 107 µJ energy, a maximum filamentary track of length 1180 µm was observed.

Baseline and longitudinal quantification of lean muscle mass using routine CT measurements prior to resection for pancreatic adenocarcinoma.

198 Background: When compared to healthy populations subjects are defined as sarcopenic if they have severe loss of lean muscle mass (LMM). Sarcopenia is associated with poor outcomes in some studies of pancreatic cancer (PDA) but the prevelance remains uncertain in resected patients and there is little data about changes in LMM during neoadjuvant chemotherapy. Muscle mass can be reliably quantified in cancer patients using routine imaging. We analyzed a large cohort of patients undergoing surgery at a high-volume center to quantify LMM at baseline and with treatment, and to determine the association of sarcopenia with tumor histology and outcomes. Methods: We analyzed subjects undergoing surgery for PDA at the Pancreas Center at Columbia University from 2011-2014. We utilized CT scans to measure cross sectional area of muscle at the L3 vertebral body (LMM in cm2) and used height to define a smooth muscle index (SMI-cm/m). Sarcopenia was determined based on SMI &lt; 38.9 for females and &lt; 55.4 for males. In subjects undergoing neoadjuvant chemotherapy, SMI was also calculated on post therapy scans. We collected information on clinical and pathological variables and performed statistical analyses utilizing SAS 9.4 software. Results: Among subjects with available imaging (n = 106) sarcopenia rates at initial staging were high whether they were immediately resectable (52%) or locally advanced (63%). Rates of sarcopenia were higher in males than females (77 vs 38%, p &lt; 0.001). Sarcopenic status was not correlated with survival, tumor stage or grade but was associated with age, gender, and BMI. Among locally advanced subjects who proceeded to surgery after neoadjuvant chemotherapy (n = 40) there was no change in SMI or incidence of sarcopenia following treatment (median 171 days). Conclusions: Sarcopenia is highly prevalent at diagnosis in subjects undergoing surgery for PDA but was not associated with survival, tumor grade or stage in this cohort. Subjects who successfully completed neoadjuvant treatment did not experience significant loss in LMM despite extensive treatment suggesting that lack of change in LMM may assist in predicting favorable response to neoadjuvant therapy in PDA.