An improved algorithm based on equivalent sound velocity profile method at large incident angle

With the development of ultra-wide coverage technology,multibeam echo-sounder(MBES)system has put forward higher requirements for localization accuracy and computational efficiency of ray tracing method.The classical equivalent sound speed profile(ESSP)method replaces the measured sound velocity profile(SVP)with a simple constant gradient SVP,reducing the computational workload of beam positioning.However,in deep-sea environment,the depth measurement error of this method rapidly increases from the central beam to the edge beam.By analyzing the positioning error of the ESSP method at edge beam,it is discovered that the positioning error increases monotonically with the incident angle,and the relationship between them could be expressed by polynomial function.Therefore,an error correction algorithm based on polynomial fitting is obtained.The simulation experiment conducted on an inclined seafloor shows that the proposed algorithm exhibits comparable efficiency to the original ESSP method,while significantly improving bathymetry accuracy by nearly eight times in the edge beam.

Study on the optimal incident proton energy of ^(7)Li(p,n)^(7)Be neutron source for boron neutron capture therapy

Boron neutron capture therapy(BNCT)is recognized as a precise binary targeted radiotherapy technique that effectively eliminates tumors through the^(10)B(n,α)^(7)Li nuclear reaction.Among various neutron sources,accelerator-based sources have emerged as particularly promising for BNCT applications.The^(7)Li(p,n)^(7)Be reaction is highly regarded as a potential neutron source for BNCT,owing to its low threshold energy for the reaction,significant neutron yield,appropriate average neutron energy,and additional benefits.This study utilized Monte Carlo simulations to model the physical interactions within a lithium target subjected to proton bombardment,including neutron moderation by an MgF_(2)moderator and subsequent BNCT dose analysis using a Snyder head phantom.The study focused on calculating the yields of epithermal neutrons for various incident proton energies,finding an optimal energy at 2.7 MeV.Furthermore,the Snyder head phantom was employed in dose simulations to validate the effectiveness of this specific incident energy when utilizing a^(7)Li(p,n)^(7)Be neutron source for BNCT purposes.

Radical cholecystectomy without liver resection for peritoneal side early incidental gallbladder cancer

Gallbladder cancer(GBC)is a rare disease with a poor prognosis.Simple cholecystectomy may be an adequate treatment only for very early disease(Tis,T1a),whereas reoperation is recommended for more advanced disease(T1b and T2).Radical cholecystectomy should have two fundamental objectives:To radically resect the liver parenchyma and to achieve adequate clearance of the lymph nodes.However,recent studies have shown that compared with lymph node dissection alone,liver resection does not improve survival outcomes.The oncological roles of lymphadenectomy and liver resection is distinct.Therefore,for patients with incidental GBC without liver invasion,hepatic resection is not always mandatory.

Focal incidental colorectal fluorodeoxyglucose uptake:Should it be spotlighted?

Fluorine-18 fluorodeoxyglucose(F-18 FDG)positron emission tomography/computed tomography(PET/CT)has emerged as a cornerstone in cancer evaluation imaging,with a well-established history spanning several years.This imaging modality,encompassing the examination of the body from the base of the skull to the upper thighs,comprehensively covers the chest and abdominopelvic regions in a singular scan,allowing for a holistic assessment of nearly the entire body,including areas of marginal interest.The inherent advantage of this expansive scan range lies in its potential to unveil unexpected incidental abnormal hypermetabolic areas.The identification of incidental focal FDG uptake within colorectal regions during PET/CT scans is not an uncommon occurrence,albeit fraught with challenges associated with non-specific FDG uptake.The presence of benign colorectal lesions or physiological uptake poses a particular obstacle,as these may manifest with FDG uptake levels that mimic malignancy.Consequently,physicians are confronted with a diagnostic dilemma when encountering abnormal FDG uptake in unexpected colorectal areas.Existing studies have presented divergent results concerning these uptakes.Standardized uptake value and its derivatives have served as pivotal metrics in quantifying FDG uptake in PET images.In this article,we aim to succinctly explore the distinctive characteristics of FDG,delve into imaging findings,and elucidate the clinical significance of incidental focal colorectal uptake.This discussion aims to contribute valuable insights into the nuanced interpretation of such findings,fostering a comprehensive understanding.

Hemangioblastoma Incidentally Discovered at CT Scan in Bamako: About a Case

Hemangioblastomas are benign vascular tumors of the brain. These are rare tumors, usually located in the cerebellum and most often affecting young adults. The aim was to study the value of CT in the management of hemangioblastoma through observation. We report the case of a 38-year-old patient referred to the radiology and Medical Imaging Department of the Marie Curie Medical Clinic in Bamako, Mali, for an orbito-cerebral CT scan in a context of bilateral eyelid edema. The examination was performed using multi-slice computed tomography (16 slices) with reconstruction in the 3 planes of space without and with the injection of an iodinated contrast agent. The CT scan was crucial in making the diagnosis of hemangioblastoma incidentally, which allowed for adequate management. The patient was operated on, and the radiological outcome was favorable, without significant cystic formation, after postoperative control and clinical signs were resolved. CT can be an interesting alternative in countries like ours despite MRI being the examination of choice in hemangioblastomas.

Training for Vessel Collision Prevention:Circumstances and Causes of Near-Miss Incidents

Among the near-miss incidents related to the operation of training ship of the JMETS(Japan Agency of Maritime Education and Training for Seafarers),three characteristic cases were analyzed,extracting their circumstances and near-miss factors.Based on the results of these analyses,measures to prevent vessel collisions were studied,from which we proposed collision prevention training.The training entails(1)lookout training,(2)navigation planning training,(3)resource management training,and(4)false assumption prevention training.In future research,we aim to verify the effectiveness of the proposed training,improve the training’s effectiveness,and contribute to the development of effective anti-collision support devices.

Design and analysis of traffic incident detection based on random forest

In order to avoid the noise and over fitting and further improve the limited classification performance of the real decision tree, a traffic incident detection method based on the random forest algorithm is presented. From the perspective of classification strength and correlation, three experiments are performed to investigate the potential application of random forest to traffic incident detection： comparison with a different number of decision trees; comparison with different decision trees; comparison with the neural network. The real traffic data of the 1-880 database is used in the experiments. The detection performance is evaluated by the common criteria including the detection rate, the false alarm rate, the mean time to detection, the classification rate and the area under the curve of the receiver operating characteristic （ROC）. The experimental results indicate that the model based on random forest can improve the decision rate, reduce the testing time, and obtain a higher classification rate. Meanwhile, it is competitive compared with multi-layer feed forward neural networks （MLF）.

Optimal dispatching method of traffic incident rescue resource for freeway network

An optimal resource dispatching method is proposed to solve the multiple-response problem under the conditions of potential incidents on freeway networks.Travel time of the response vehicle is selected instead of route distance as the weight to reflect the impact of traffic conditions on the decisions of rescue resources.According to the characteristics of different types of rescue vehicles the dispatching decision-making time is revised to show the heterogeneity among different rescue vehicle dispatching modes. The genetic algorithm is used to obtain the solutions to the rescue resources dispatching model. A case study shows that the proposed method can accurately reveal the impact of potential incidents on the costs of rescues according to the variations in the types and quantities of rescue resources and the optimal dispatching plan with respect to potential incidents can be obtained.The proposed method is applicable in real world scenarios.

Hierarchical decision-making system for real-time freeway incident response

The artificial intelligence technique is used to generate a freeway incident response plan. The incident response framework based on rule-based reasoning, case-based reasoning and Bayesian networks reasoning is presented. First, a freeway incident management system （RK-IMS） based on rule-based reasoning is developed and applied for incident management in the northern section of the Nanjing-Lianyunguang Freeway. Then, field data from the two-year long operations of the RK-IMS are analyzed. Representations of incident case structures and Bayesian networks（BNs） structures related to incident responses are deduced. Finally, the k-nearest neighbor （k-NN） algorithm is applied to calculate the similarities of the cases. The preplan generation and the control strategy by integrating the k-NN algorithm are also developed. The model is validated by using incident data of the year 2006 from the RK-IMS. The comparison results indicate that the proposed algorithm is accurate and reliable.

A Literature Review on Freeway Traffic Incidents and Their Impact on Traffic Operations

Congestion on the freeway is more frequent due to several traffic incidents, namely traffic accidents, debris on the road, vehicle breakdown, and collision with guardrails than any other incidents. These, in turn, affect the operational performance of the freeway by increasing queue length, volume, and density. Consequently, effective freeway management strategies can help to minimize these impacts. The study investigates and summarizes existing studies to identify the reasons for and effects of the traffic incidents. Attention is given to the available solutions of the freeway traffic incidents management. The ultimate goal of this study is to identify the gaps which are not yet addressed to improve the operational effectiveness of the freeway. This study was conducted through a comprehensive literature review of existing refereed publications, established standards, and formal guidelines. Literature was sought through the Transport Research International Documentation (TRID) database, IEEE Transactions database, and google scholar search engine. Research focusing on freeway traffic incidents is a growing concern in transportation operations, as transportation network performance depends on it. Due to the advancement of technology, emerging vehicle technologies like connected vehicles have the potential to address these problems affecting the US transportation system and revolutionize mobility in the future. The study can serve as a reference for the researchers that are involved in freeway traffic operations.

IMPROVING MATERIAL REMOVAL RATE OF BRITTLE CERAMICS THROUGH HONING INCIDENTAL TENSILE STRESSES

The stress intensity factors and stress conditions of machining cracks are analyzed by fracture mechanics on the basis of honing characteristics and of brittle ceramic mechanical behavior.Because the honing incidental tensile stresses effectively decrease the critical grinding stresses and increase the stress intensity factors of machining cracks,the honing process can be carried out easily.The results show that honing can be an efficient machining method for brittle materials.

Incidental gallbladder cancer diagnosis confers survival advantage irrespective of tumour stage and characteristics

BACKGROUND Incidental gallbladder cancer(IGBC)represents 50%-60%of gallbladder cancer cases.Data are conflicting on the role of IGBC diagnosis in oncological outcomes.Some studies suggest that IGBC diagnosis does not affect outcomes,while others that overall survival(OS)is longer in these cases compared to non-incidental diagnosis(NIGBC).Furthermore,some studies reported early tumour stages and histopathologic characteristics as possible confounders,while others not.AIM To investigate the role of IGBC diagnosis on patients’overall survival,especially after surgical treatment with curative intent.METHODS Retrospective analysis of all patient referrals with gallbladder cancer between 2008 and 2020 in a tertiary hepatobiliary centre.Statistical comparison of patient and tumour characteristics between IGBC and NIGBC subgroups was performed.Survival analysis for the whole cohort,surgical and non-surgical subgroups was done with the Kaplan-Meier method and the use of log rank test.Risk analysis was performed with univariable and multivariable Cox regression analysis.RESULTS The cohort included 261 patients with gallbladder cancer.65%of cases had NIGBC and 35%had IGBC.A total of 90 patients received surgical treatment(66%of IGBC cases and 19%of NIGBC cases).NIGBC patients had more advanced T stage and required more extensive resections than IGBC ones.OS was longer in patients with IGBC in the whole cohort(29 vs 4 mo,P<0.001),as well as in the non-surgical(14 vs 2 mo,P<0.001)and surgical subgroups(29 vs 16.5 mo,P=0.001).Disease free survival(DFS)after surgery was longer in patients with IGBC(21.5 mo vs 8.5 mo,P=0.007).N stage and resection margin status were identified as independent predictors of OS and DFS.NIGBC diagnosis was identified as an independent predictor of OS.CONCLUSION IGBC diagnosis may confer a survival advantage independently of the pathological stage and tumour characteristics.Prospective studies are required to further investigate this,including detailed pathological analysis and molecular gene expression.

Monitoring Freeway Incident Detection Using a Hotelling T2 Control Chart

In real-life freeway transportation system, a few number of incident observation （very rare event） is available while there are large numbers of normal condition dataset. Most of researches on freeway incident detection have considered the incident detection problem as classification one. However, because of insufficiency of incident events, most of previous researches have utilized simulated incident events to develop freeway incident detection models. In order to overcome this drawback, this paper proposes a wavelet-based Hotelling 7a control chart for freeway incident detection, which integrates a wavelet transform into an abnormal detection method. Firstly, wavelet transform extracts useful features from noisy original traffic observations, leading to reduce the dimensionality of input vectors. Then, a Hotelling T2 control chart describes a decision boundary with only normal traffic observations with the selected features in the wavelet domain. Unlike the existing incident detection algorithms, which require lots of incident observations to construct incident detection models, the proposed approach can decide a decision boundary given only normal training observations. The proposed method is evaluated in comparison with California algorithm, Minnesota algorithm and conventional neural networks. The experimental results present that the proposed algorithm in this paper is a promising alternative for freeway automatic incident detections.

Evaluation model for freeway incident management system

In order to evaluate the general situation and find special problems of the freeway incident management system, an evaluation model is proposed. First, the expert appraisal approach is used to select the primary evaluation index. As a result, 81 indices and the hierarchical structures of the index such as the object layer, the sub-object layer, the criterion layer and the index layer are determined. Then, based on the fuzzy characteristics of each index layer, the analytical hierarchy process（AHP）and the fuzzy comprehensive evaluation are applied to generate the weight and the satisfaction of the index and the criterion layers. When analyzing the relationship between the sub-object layer and the object layer, it is easy to find that the number of sub-objects is too large and sub-objects are significantly redundant. The partial least square （PLS） is proposed to solve the problems. Finally, an application example, whose result has already been accepted and employed as the indication of a new project in improving incident management, is introduced and the result verifies the feasibility and efficiency of the model.

Acoustic evaluation of cementing quality using obliquely incident ultrasonic signals

Ultrasonic cement bond logging is a widely used method for evaluating cementing quality. Conventional ultrasonic cement bond logging uses vertical incidence and cannot accurately evaluate lightweight cement bonding. Oblique incidence is a new technology for evaluating cement quality with improved accuracy for lightweight cements. In this study, we simulated models of acoustic impedance of cement and cementing quality using ultrasonic oblique incidence, and we obtained the relation between cementing quality, acoustic impedance of cement, and the acoustic attenuation coeffi cient of the A0-mode and S0-mode Lamb waves. Then, we simulated models of different cement thickness and we obtained the relation between cement thickness and the time difference of the arrival between the A0 and A0′ modes.

Prevalence of incidental prostate cancer in patients undergoing radical cystoprostatectomy： data from China and other Asian countries

The purpose of this study is to investigate the frequency of prostate cancer （Pca） discovered incidentally in radical cystoprostatectomy specimens in Asia and to determine the feasibility of prostate-sparing cystectomy （PSC） for Asian patients. Ninety-two male bladder cancer patients who underwent radical cystoprostatectomy at our center between January 2003 and January 2008 were included in this study. The mean age of patients was 67.1 years （range： 32-75 years）. Prostate-specific antigen （PSA） levels and digital rectal examination （DRE） results before surgery were obtained retrospectively. Prostates of all patients were embedded and sectioned at 5-mm intervals. The same pathologist examined the prostatic tissues from radical cystoprostatectomy specimens. Finally, a structured literature review was performed using MEDLINE and PUBMED to estimate the occurrence of incidental Pca in Asia. Of the 92 patients, 3 （3.3%） were found to have Pca; in one out of three （33.3%） patients the disease was clinically significant due to a Gleason grade 4 carcinoma. Eight articles were included in our review. The overall incidence of Pca discovered incidentally in radical cystoprostatectomy specimens in Asia was 9.9% （64/642）. When age was restricted to 〈 60 years, only 7 out of 222 （3.2%） patients were found to have synchronous Pca, and none of the cases was clinically significant. The occurrence of Pca in radical cystoprostatectorny specimens in Asia is much lower than that in Western countries. PSC might be feasible for Asian patients under a strict preoperative selection.

Reflection of Oblique Incident Waves by Breakwaters with Partially-Perforated Wall

The reflection of oblique incident waves from breakwaters with a partially-perforated front wall is investigated. The fluid domain is divided into two sub-domains and the eigenfunction expansion method is applied to expand velocity potentials in each domain. In the eigen-expansion of the velocity potential, evanescent waves are included. Numerical results of the present model are compared with experimental data. The effect of porosity, the relative chamber width, the relative water depth in the wave absorbing chamber and the water depth in front of the structure are discussed.

Incidental gall bladder cancers:Are they truly incidental?

AIM: To seek and analyze features suggestive of gallbladder cancer(GBC) on preoperative imaging and intraoperative findings in patients diagnosed as having incidental GBC(IGBC). METHODS: The study was conducted on 79 patients of IGBC managed in our department over a 10-year period(2003-2012). Review of preoperative imaging and operative notes was done to ascertain any suspicion of malignancy-in-retrospect.RESULTS: Of the 79 patients, Ultrasound abdomen showed diffuse thickening, not suspicious of malignancy in 5 patients, and diffuse suspicious thickening was seen in 4 patients. Focal thickening suspicious of malignancy was present in 24 patients. Preoperative computed tomography/magnetic resonance imaging was done in 9 patients for suspicion of malignancy. In 5 patients, dif-ficult Cholecystectomy was encountered due to dense/inflammatory adhesions. Intraoperative findings showed focal thickening of the gallbladder and a gallbladder mass in 9 and 17 patients respectively. On overall analysis, 37 patients had preoperative imaging or intraoperative findings suggestive of malignancy, which was either a missed GBC or an unsuspected/unexpected GBC. In 42(53.2%) patients, there was no evidence suggestive of malignancy and was an unanticipated diagnosis.CONCLUSION: Our study highlights a potential and not-so-rare pitfall of Laparoscopic Cholecystectomy. A greater awareness of this clinical entity along with a high index of suspicion and a low threshold for conversion to open procedure, especially in endemic areas may avert avoidable patient morbidity and mortality.

The force of oblique incident wave on the breakwater with a partially perforated wall

Wave forces induced by the interaction between the oblique incident wave and the breakwater with a partially perforated front wall is investigated. The fluid domain is divided into two sub-domains and the eigen-function expansion method is applied to expanding velocity potentials in each domain. In the eigen-expansion of the velocity potential, evanescent waves are included. Numerical results of the present model are compared with other theories and a good agreement can be found between them. Experimental data have been compared with the present theoretical results. The effect of the traverse wall on wave forces has been discussed in detail. On the basis of the linear wave theory, it is shown that in the range Of engineering practice, the incident angle of wave has small influence on wave forces on the unit length of perforated caisson.

Incidental non-benign gallbladder histopathology after cholecystectomy in an United Kingdom population: Need for routine histological analysis?

AIM To analyse the range of histopathology detected in the largest published United Kingdom series of cholecystectomy specimens and to evaluate the rational for selective histopathological analysis.METHODS Incidental gallbladder malignancy is rare in the United Kingdom with recent literature supporting selective histological assessment of gallbladders after routine cholecystectomy.All cholecystectomy gallbladder specimens examined by the histopathology department at our hospital during a five year period between March 2008 and March 2013 were retrospectively analysed.Further data was collected on all specimens demonstrating carcinoma,dysplasia and polypoid growths.RESULTS The study included 4027 patients.The majority(97%) of specimens exhibited gallstone or cholecystitis related disease.Polyps were demonstrated in 44(1.09%),the majority of which were cholesterol based(41/44).Dysplasia,ranging from low to multifocal high-grade was demonstrated in 55(1.37%).Incidental primary gallbladder adenocarcinoma was detected in 6 specimens(0.15%,5 female and 1 male),and a single gallbladder revealed carcinoma in situ(0.02%).This large single centre study demonstrated a full range of gallbladder disease from cholecystectomy specimens,including more than 1% neoplastic histology and two cases of macroscopically occult gallbladder malignancies.CONCLUSION Routine histological evaluation of all elective and emergency cholecystectomies is justified in a United Kingdom population as selective analysis has potential to miss potentially curable life threatening pathology.