A comparison of regression models for the ice loads measured during the ice tank test

To evaluate the time-domain positioning performance of arctic marine structures, it is necessary to generate an ice load appropriate for the current position and heading of the structure. The position and orientation angle of a floating body continuously change with time. Therefore, an ice load is required for any attitude in the time-domain simulation. In this study, we present a fundamental technique for analyzing ice loads in the frequency domain based on data measured at various angles in the ice-water tank experiment. We perform spectral analysis instead of general FFT to analyze the ice load, which has the characteristics of a random signal. To generate the necessary ice load in the time domain, we must first interpolate the measured data in the frequency domain. Using the Blackman-Tukey method, we estimate the spectrum for the measured data, then process the data to generate the training set required for machine learning. Based on the results, we perform regression analysis by applying four representative techniques, including linear regression, random forest, or neural network, and compare the results with MSE. The deep neural network method performed best, but we provide further discussion for each model

Accuracy of dental implant placement with computer-guided surgery: a retrospective cohort study

Abstract Background The aim of this study was to assess the accuracy of virtual planning of computer-guided surgery based on the actual outcomes of clinical dental implant placement. Methods This retrospective study enrolled patients among whom implant treatment was planned using computer-guided surgery with cone beam computed tomography (CBCT). The patients who received implant according to the guide with the flapless and flapped approach were classified as group 1 and 2, respectively, and the others who could not be placed according to the guide were allocated to the drop-out group. The accuracy of implant placement was evaluated with the superimposition of CBCT. Results We analyzed differences in the deviated distance of the entrance point and deviated angulation of the insertion of implant fixtures. With regard to the surgical approach, group 2 exhibited greater accuracy compared to group 1 in deviation distance (2.22 ± 0.88 and 3.18 ± 0.89 mm, respectively, P < 0.001) and angulation (4.27 ± 2.30 and 6.82 ± 2.71°, respectively, P = 0.001). The limitations of guided surgery were discussed while considering the findings from the drop-out group. Conclusions Computer-guided surgery demonstrates greater accuracy in implant placement with the flapless approach. Further research should be conducted to enhance the availability of guides for cases with unfavorable residual bone conditions

Considerations for physicians using ketamine for sedation of children in emergency departments

Objective Ketamine use in emergency departments (EDs) for procedural sedation and analgesia is becoming increasingly common. However, few studies have examined patient factors related to adverse events associated with ketamine. This study investigated factors for consideration when using ketamine to sedate pediatric ED patients. Methods The study included pediatric patients receiving ketamine for laceration repair in the ED. Before sedation, information was collected about upper respiratory tract infection symptoms, allergy history, and fasting time. Patients received 2 mg/kg ketamine intravenously or 4 mg/kg ketamine intramuscularly. The primary outcomes were adverse events due to ketamine. Results We studied 116 patients aged 8 months to 7 years (2.8±1.5 years). The group with adverse events was significantly younger on average than the group without adverse events (2.5±1.5 vs. 3.1±1.5, P=0.028). Upper respiratory tract infection symptoms were not significant variables affecting ketamine sedation (48.9% vs. 43.7%, P=0.719). There was no significant association between duration of fasting and adverse events (P=0.073 and P=0.897, respectively), or between food type and adverse events (P=0.734). However, the number of attempts to sedate and ketamine dose correlated with adverse events (P<0.001 and P=0.022, respectively). In multiple logistic regression analysis, intravenous injection and ketamine dose were significant factors (odds ratio, 16.77; 95% confidence interval, 1.78 to 498.54; odds ratio, 4.37; 95% confidence interval, 1.59 to 22.9, respectively). Conclusion Emergency medicine physicians should consider injection type and ketamine dose when using ketamine sedation while suturing lacerations

A Possible Mechanism Underlying the Effectiveness of Acupuncture in the Treatment of Drug Addiction

Clinical trials are currently underway to determine the effectiveness of acupuncture in the treatment of drug addiction. While there are still many unanswered questions about the basic mechanisms of acupuncture, some evidence exists to suggest that acupuncture can play an important role in reducing reinforcing effects of abused drugs. The purpose of this article is to critically review these data. The neurochemical and behavioral evidence showed that acupuncture's role in suppressing the reinforcing effects of abused drugs takes place by modulating mesolimbic dopamine neurons. Also, several brain neurotransmitter systems such as serotonin, opioid and amino acids including GABA have been implicated in the modulation of dopamine release by acupuncture. These results provided clear evidence for the biological effects of acupuncture that ultimately may help us to understand how acupuncture can be used to treat abused drugs. Additional research using animal models is of primary importance to understanding the basic mechanism underlying acupuncture's effectiveness in the treatment of drug addiction

Liposarcoma: exploration of clinical prognostic factors for risk based stratification of therapy

<p>Abstract</p> <p>Background</p> <p>Prognosis and optimal treatment strategies of liposarcoma have not been fully defined. The purpose of this study is to define the distinctive clinical features of liposarcomas by assessing prognostic factors.</p> <p>Methods</p> <p>Between January 1995 and May 2008, 94 liposarcoma patients who underwent surgical resection with curative intent were reviewed.</p> <p>Results</p> <p>Fifty patients (53.2%) presented with well differentiated, 22 (23.4%) myxoid, 15 (16.0%) dedifferentiated, 5 (5.3%) round cell, and 2 (2.1%) pleomorphic histology. With the median 14 cm sized of tumor burden, about half of the cases were located in the retroperitoneum (46.8%). Seventy two (76.6%) patients remained alive with 78.1%, and 67.5% of the 5- and 10-year overall survival (OS) rates, respectively. Low grade liposarcoma (well differentiated and myxoid) had a significantly prolonged OS and disease free survival (DFS) with adjuvant radiotherapy when compared with those without adjuvant radiotherapy (5-year OS, 100% vs 66.3%, P = 0.03; 1-year DFS, 92.9% <it>vs </it>50.0%, respectively, P = 0.04). Independent prognostic factors for OS were histologic variant (P = 0.001; HR, 5.1; 95% CI, 2.0 – 12.9), and margin status (P = 0.005; HR, 4.1; 95% CI, 1.6–10.5). We identified three different risk groups: group 1 (n = 66), no adverse factors; group 2, one or two adverse factors (n = 28). The 5-year OS rate for group 1, and 2 were 91.9%, 45.5%, respectively.</p> <p>Conclusion</p> <p>The histologic subtype, and margin status were independently associated with OS, and adjuvant radiotherapy seems to confer survival benefit in low grade tumors. Our prognostic model for primary liposarcoma demonstrated distinct three groups of patients with good prognostic discrimination.</p

A Kinematic Collision Box Algorithm Applied for the Anti-Collision System of Offshore Drilling Vessels

With the advances in technology and the automation of drilling platforms, the Anti-Collision System (ACS) has appeared as an affordable technology, which is intended to keep equipment on the drilling floor working harmoniously and to prevent the potential hazards associated with accidents. However, the specialty of the machinery on the drilling floor requires a distinguished structure for the ACS and a reliable collision-avoidance algorithm, which is not similar to any algorithm in other applications, such as automobiles and robotics. The aim of this paper is to provide a comprehension of the configuration of an ACS in an Integrated Drilling System and to develop a practical anti-collision algorithm that can be applied to the machine arrangement for an offshore drilling operation. By analyzing the motions and using kinematic parameters, such as the speed and deceleration information of drilling equipment, a kinematic collision box algorithm is developed to eliminate the limitation of conventional algorithms. While the conventional collision-avoidance algorithm uses a collision box with fixed size, the kinematic collision box algorithm uses a collision box with a flexible scale that can be correspond to the velocity and deceleration rate of the equipment. Several operating scenarios are simulated by a visual model of ACS to authenticate the functionality of the proposed algorithm. The operation of the top drive is an outstanding scenario. Only 2.25 s are required to stop the top drive from its maximum velocity, and a conventional algorithm uses this number to create a fixed bounding box. Also, the kinematic collision box algorithm uses the real-time data of velocity and acceleration to adjust the scale of the bounding box when the speed of the top drive increases from 0 to its maximum value. The simulation result illustrates the reliability and advances of the kinematic collision box algorithm in performing the collision-avoidance function in ACS compared to the conventional algorithm

Nanocrystalline MOFs Embedded in the Crystals of Other MOFs and Their Multifunctional Performance for Molecular Encapsulation and Energy-Carrier Storage

A metal–organic framework (MOF) with a specific construction and pores was demonstrated to have many advanced properties, but still limited to having unique aspects arising from the combination of different MOFs in a single body. Here, we report a facile method to produce MOF-5 crystals with nanocrystalline HKUST-1 (nHKUST-1) embedded into them in what is termed the “nHKUST-1⊂MOF-5” structure. The results show that the nHKUST-1⊂MOF-5 structure is capable of molecular encapsulation by trapping dye molecules in nHKUST-1 particles and embedding them in MOF-5 crystals. Moreover, the gravimetric uptake capacity of nHKUST-1⊂MOF-5 for methane (CH₄) was found to be enhanced as compared to that of MOF-5 or nHKUST-1 alone such that the nHKUST-1⊂MOF-5 structure exhibits a volumetric capacity of 250% for fuel storage deliverable by the CNG tank at room temperature and 80 bar. Furthermore, it showed robust capacity retention for reversible CH₄ uptake cycles at room temperature

Fabrication of heterogeneous exposed core-shell catalyst array using the space specificity of an embodied micelle and their application to a high performance photocatalyst

We report a new recipe to synthesize heterogeneous catalyst arrays using the space specificity of an embodied micelle. Also, SEM, AFM, STEM, and TXRF analyses prove that these catalysts are of exposed core-shell types. Furthermore, their structures were found to allow the design of a high performance photocatalyst for water splitting.close0