Time Of Occurrence Research Articles

First Observation of Harmonics of Magnetosonic Waves in Martian Magnetosheath Region

AbstractThe present study provides an evidence for the generation of harmonics of magnetosonic waves in the Martian magnetosheath region. The wave signatures are manifested in the magnetic field measurements recorded by the fluxgate magnetometer instrument onboard the Mars Atmosphere and Volatile Evolution missioN (MAVEN) spacecraft in the dawn sector around 5–10 LT at an altitude of 4,000–6,000 kms. The wave that is observed continuously from 19.1 to 20.7 UT below the proton cyclotron frequency (fci ≈ 46 mHz) is identified as fundamental mode of the magnetosonic wave. Whereas harmonics of the magnetosonic wave are observed during 19.7–20.3 UT at frequencies that are multiple of fci. The ambient solar wind proton density and plasma flow velocity are found to vary with a fundamental mode frequency of 46 mHz. It is noticed that the fundamental mode is mainly associated with the left‐hand (LH), and higher frequency harmonics are associated with the right‐hand (RH) circular polarizations. A clear difference in the polarization and ellipticity is noticed during the time of occurrence of harmonics. The magnetosonic wave harmonics are found to propagate in the quasi‐perpendicular directions to the ambient magnetic field. The results of linear theory and Particle‐In‐Cell simulation performed here are in agreement with the observations. The present study provides a conclusive evidence for the occurrence of harmonics of magnetosonic wave in the close vicinity of the magnetosheath region of the unmagnetized planet Mars.

Time association study on a sub-acute mouse model of Parkinson’s disease

Parkinson's disease (PD) is a severe neurodegenerative disease that disturbs human health. In the laboratory researches about PD, the mice model induced by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was widely used. However, there has been controversy about the model effectiveness to simulate PD symptoms and pathology, and the time-varying development of behavioral and pathological characteristic after MPTP treatment remains unclear. In order to solve these problems, we designed a series of experiments to evaluate this PD model at different time points. We constructed the subacute PD mouse model by intraperitoneal injection of MPTP for 5 consecutive days. The rotarod test, open field test and the immunohistochemical staining of tyrosine hydroxylase were conducted at −5, 1, 5, 7, 14, 21 and 28 days after the last injection of MPTP. The results showed that 5 days after the last MPTP administration, typical motor disorders with significant balance function damage in rotarod test began to appear and remained stable throughout the entire experiment. Simultaneously, we also observed the loss of tyrosine hydroxylase (TH) positive cells in the substantia nigra compacta and reduction of TH content in the striatum but this pathological change in the substantia nigra compacta reversed 21 days after injection. Besides, the spontaneous movement of mice in open field test remained unchanged by MPTP. This research indicated the time-dependence of MPTP neurotoxicity that impair the motor function and histological features and confirmed the symptom occurrence time after MPTP injection, which provides a reference for the future research about MPTP-induced PD.

Exploring the Contributory Factors of Homicide Victimization within the Province of Pampanga, Philippines

In the province of Pampanga, Philippines, particularly from 2019-2022, homicide victimization is considered the third highest crime category in the region. This study aimed to address this gap by exploring and evaluating the factors contributing to homicide victimization in Pampanga during the specific years. The descriptive research design was employed using the survey questionnaire and secondary data sources to answer the objectives of the study. A survey questionnaire was distributed purposively to 101 Police Commissioned Officers (PCO) and Police Non-Commissioned Officers (PNCO) stationed at various police stations in Pampanga. The study revealed that the homicide incidents in the province of Pampanga, Philippines from 2019-2022 occurred often in the evening and midnight during the first quarter. Homicide incidents can occur in public and private places and the perpetrators were sometimes under the influence of alcohol/liquor, and the weapons often used were guns/firearm, knives, and other blunt/bladed instruments. The motives of the perpetrators are usually out of anger or hatred, heated argument and revenge, and the often modus operandi were shooting the victims and stabbing or hacking the victims. Furthermore, the study also revealed that the crime prevention programs to prevent the occurrence of homicide incidents in Pampanga, Philippines were always implemented. Positive correlations were observed to the time of occurrence, involvement of perpetrators, weapons used, motives and community involvement.

Optimization of technological parameters of the methane tri-reforming process based on the phenomenon of conservatively perturbed equilibrium

course under the condition of the phenomenon of conservative perturbed equilibrium (CPE) are considered. It is shown that the onset of the CPE point - an extremum of the over-equilibrium concentration - occurs at a certain point in time. Therefore, one of the tasks of optimal control is to calculate the time of occurrence of this point and determine the effect of temperature and pressure on its position. The modeling of the TRM process is performed for an ideal displacement reactor. The DWSIM software product was used to model the TRM process. The kinetic equations were programmed in the form of scripts. The position of the over-equilibrium concentration point was also investigated depending on the initial composition of the mixture. According to the modeling results, it was concluded that the position of the CPE point for product H₂ is constant, and depends only on pressure and temperature and does not depend on the initial composition of the mixture. This allows us to conclude that the control can ensure that the product yield with the maximum concentration is achieved. The problem of optimizing the initial composition of the mixture for the methane tri-reforming process using CPE is formulated: the objective function and constraints are defined, and the solution method is chosen. The optimization problem is to maximize the target product of methane tri-reforming, H2. The solution to the problem is the composition of the mixture (concentrations of CH4, H2O, CO2). As for the constraints, the pressure and temperature are limited by the physicochemical properties of the process and the design features of the reactor, the elemental balance must be maintained, the key component at the input must have an equilibrium concentration at a given pressure and temperature, and the concentrations of other components must be deviated from their equilibrium values. A software implementation of the optimization problem based on the Optimization Toolbox Matlab was performed. The research results indicate an increase in the efficiency of the process (increase in the output of the target component) and the possibility of implementing optimal solutions in real time, which opens up prospects for implementation in existing control systems and development of decision-making systems.

A Study on the Impact of Low-Frequency Random Loading and Unloading on Silo Structures

To investigate the development of cracks in the walls of reinforced concrete silos under feeding–discharge cycle loading, their causes, and their fatigue life during dynamic loading, a study was conducted using a combination of in situ monitoring and numerical simulation analysis. The following conclusions were drawn: during the loading and unloading process of the silo, the time of occurrence of the minimum pressure points follows a 4:3 ratio; extreme points are approximately 15 min apart; the minimum pressure increases during material addition and decreases during material subtraction; and the load in the non-discharge area is 1.43 times that of the load in the discharge area. That is, at the same elevation, the load borne by the silo wall is uneven, with fluctuations and rotational effects occurring. Under such uneven load conditions, the silo wall experiences significant bending and torsional moments, causing excessive local tension and leading to cracking. Our analysis showed that the most unfavorable load condition occurs when discharge ports 5 and 7 are operating simultaneously, which causes the maximum tensile damage to the silo wall. For the first time, a fatigue life prediction model for reinforced concrete silos was proposed, and the accuracy of this prediction method was verified based on actual conditions.

Intelligent identification and quantification method of rockburst behavior characteristics based on vision and 3D laser point cloud technology

Aiming at the problem of recording rockburst events, a safe and intelligent identification technology and instrument are developed. The instrument mainly consists of a network spherical camera and LiDAR. Corresponding processing algorithms have been developed to automatically measure the occurrence time, location, velocity, and size of rockfalls during rockburst. The instrument was applied to a tunnel construction site in Southwest China, where 96 rockburst events were collected and identified. The results show that: rockburst in this tunnel mostly occur at the vault and right arch shoulder, mainly within 150 min after the tunnel face blasting, the velocity of the falling rocks can reach 12.297 m/s, the falling process is only about 1 s, and the size of the falling rocks is mainly stones smaller than 0.2 m3. The results indicate that this method has good detection performance and can provide beneficial technology and equipment for further statistical analysis of the occurrence patterns of rockburst.

Study on the Preventive Effect of Au/CeO2 on Lithium-Ion Battery Thermal Runaway Caused by Overcharging

In this study, a flower-like Au/CeO2 supported catalyst composite anode was prepared to explore its impact on thermal runaway triggered by overcharging and flame. Through structural and performance characterization, it was found that the catalyst has a high specific surface area and good CO catalytic oxidation capability, with a CO removal rate higher than 99.97% at room temperature. Through electrical performance testing, it was discovered that, compared to batteries without the catalyst, batteries using the composite anode did not exhibit significant capacity degradation. In overcharge testing, the catalyst prolonged the voltage rise time and peak voltage occurrence time of the battery. In thermal runaway testing, the addition of the catalyst delayed the detection time of CO and significantly reduced the concentration of thermal runaway products, especially the peak concentration and integrated concentration of CO, demonstrating its effectiveness in reducing thermal runaway products. Therefore, this study provides a new approach for improving the safety of lithium-ion batteries. The catalyst exhibits good performance in reducing toxic gases generated after thermal runaway and delaying the occurrence of thermal runaway, providing strong support for the safe application of lithium-ion batteries.

PMUs data based detection of oscillatory events and identification of their associated variable: Estimation of information measures approach

Information theory can be a useful tool for quantifying the perturbations in the associated state variables at the time of disturbance occurrence. The study introduces a framework for the spectral decomposition of multivariate information measures to detect initiation of low frequency oscillations (LFOs), caused due to physical events in the power grid. A frequency-specific quantification of the information is shared between a target variable and two source variables from their time series data. Initially, the approach is applied on different synthetic test signals having different oscillatory frequency modes and decay time constant. Then, approach is extended on PMUs signals. The combination of cross-spectral and information-theoretic approaches is applied for the multi-variable analysis of PMUs signals from the same bus. The interdependence among the frequency, voltage angle and voltage magnitude, corresponding to specific oscillations, manifested due to cause-effect relationships obtained in terms of statistics is estimated. The dynamics in terms of unique (interaction), redundant and synergetic information is determined with the contribution from two of these three signals as source variables to target variable (frequency/voltage angle). This provides a direct coupling to identify driver-response relationships between source variables and target variable to indicate the onset of LFOs, following physical events in power network. The extension of approach among the variables from different buses aids to identify the responsible area of event occurrence.

Chemotherapy-related cardiotoxicity and its symptoms in patients with breast cancer: a scoping review

BackgroundChemotherapy-related cardiotoxicity is a significant concern because it is a major cause of morbidity. This study aimed to provide in-depth information on the symptoms of chemotherapy-related cardiotoxicity (CRCT) by exploring literature that concurrently reports the types and symptoms of CRCT in patients with breast cancer.MethodsA scoping review was performed according to an a priori protocol using the Joanna Briggs Institute’s guidelines. The participants were patients with breast cancer. The concept was the literature of specifically reported symptoms directly matched with CRCT and the literature, in English, from 2010, and the context was open. The search strategy included four keywords: “breast cancer,” “chemotherapy,” “cardiotoxicity,” and “symptoms.” All types of research designs were included; however, studies involving patients with other cancer types, animal subjects, and symptoms not directly related to CRCT were excluded. Data were extracted and presented including tables and figures.ResultsA total of 29 articles were included in the study, consisting of 23 case reports, 4 retrospective studies, and 2 prospective studies. There were no restrictions on the participants’ sex; however, all of them were women, except for one case report. The most used chemotherapy regimens were trastuzumab, capecitabine, and doxorubicin or epirubicin. The primary CRCT identified were myocardial dysfunction and heart failure, followed by coronary artery disease, pulmonary hypertension, and other conditions. Major tests used to diagnose CRCT include echocardiography, electrocardiography, serum cardiac enzymes, coronary angiography, computed tomography, and magnetic resonance imaging. In all case reports, CRCT was diagnosed through an incidental checkup according to the patient’s symptom presentation; however, only 10 of these studies showed a baseline checkup before chemotherapy. The five most common CRCT symptoms were dyspnea, chest pain, peripheral edema, fatigue, and palpitations, which were assessed by patient-reported symptom presentation rather than using a symptom assessment tool. Dyspnea with trastuzumab treatment and chest pain with capecitabine treatment were particularly characteristic. The time for first symptom onset after chemotherapy ranged from 1 hour to 300 days, with anthracycline-based regimens requiring 3–55 days, trastuzumab requiring 60–300 days, and capecitabine requiring 1–7 days.ConclusionsThis scoping review allowed data mapping according to the study design and chemotherapy regimens. Cardiac assessments for CRCT diagnosis were performed according to the patient’s symptoms. There were approximately five types of typical CRCT symptoms, and the timing of symptom occurrence varied. Therefore, developing and applying a CRCT-specific and user-friendly symptom assessment tool are expected to help healthcare providers and patients manage CRCT symptoms effectively.

Evaluating the effect of Multi-Scale droughts on autumn phenology of global land biomes with satellite observation

The end of the growing season (EOS), autumn phenology, is a significant indicator of vegetation health in terrestrial ecosystems. Higher frequency and intensity droughts are expected to have a greater impact on ecosystem homeostasis, and an urgent determination of the impact of temporal effects on autumn phenology is imperative to improve the understanding of ecosystem resilience and resistance and the stability of plant carbon sinks. This study aims to quantitatively assess the response of global autumn phenology to observed drought cumulative and lagged effects based on EOS and multi time-scales drought index (the Standardized Precipitation and Evapotranspiration Index, SPEI), and analyze the potential impact path of climate variables on EOS-SPEI relationship. Our results suggested that the cumulative and lagged effects of drought had a significant impact on the autumn phenology of approximately 27.00% and 48.73% of the vegetated area, respectively. The accumulated months were mostly concentrated on shorter time scales (1- to 3-month), and the lagged effect was mostly concentrated on 1 to 3 lagged months. These two effects on EOS were similar in different biomes and water availability, demonstrating that diverse biomes have different adaptation strategies to drought and the importance of water available for ecosystem drought mitigation. Precipitation and solar radiation had a direct negative impact on evaporation, whereas evaporation had a substantial directly positive impact on the intensity of drought effect on autumn phenology. The interaction between the climatic variables results in the accumulated months being directly positively regulated by thermal radiation, while the lagged months were directly positively influenced by precipitation, which indicates that the hydrothermal conditions at the onset of EOS occurrence govern the autumn phenology response to drought more than the occurrence time of EOS.

Время жизни поляризационного джета при длительных магнитных бурях

The paper examines conditions of occurrence and typical time scales of a polarization jet by measuring ionospheric parameters from DMSP satellites (h~830 km) and using data from the ground-based ionospheric station Yakutsk (YA462) during strong and long-term geomagnetic storms. The polarization jet at the ionospheric station Yakutsk was recorded in the dusk sector at the background of substorm disturbances when the geomagnetic index SME reached values from 1000 to ~3000 nT, and, according to data from the magnetic observatory Yakutsk (YAK), there was a positive bay ~50–100 nT in the geomagnetic field H component and ~100–200 nT in its Z component. We show that the lifetime of the polarization jet or narrow troughs in ionospheric plasma in the subauroral ionosphere during strong and long-term magnetic storms can be as long as 12 hrs.

Randomized trial comparing the effects of tulathromycin, tildipirosin and gamithromycin used as first treatment for clinical bovine respiratory disease in commercial feedlot steers

Our objective was to compare effects of 3 macrolide antibiot­ics used as first-time bovine respiratory disease (BRD) treat­ment on primary health outcomes (retreatment, removal and mortality) in feedlot steers. Secondary outcomes included days-on-feed, rectal temperature and weight at the time of event occurrences. Crossbred beef steers (n = 978; average body weight [± SD] 655 ± 84.0 lb [297 ± 38.1 kg]) were enrolled across 2 commercial feedlots in the U.S. High Plains in a ran­domized complete block design. Steers were eligible for in­clusion if they were exhibiting clinical BRD symptoms from natural exposure and had not been previously treated with an antimicrobial drug for any reason including metaphylaxis. Treatment was administration of tulathromycin, tildipirosin or gamithromycin, at the time of first BRD diagnosis. Linear and generalized linear mixed models were used for statisti­cal analyses with significance threshold α = 0.05. At enroll­ment, animal weight (P = 0.98), rectal temperature (P = 0.58), and days-on-feed (P = 0.28) did not differ significantly between treatments. There was no evidence of differences for any health outcome (P ≥ 0.30), nor for any cattle characteristics at the time of retreatment, removal, or mortality (P ≥ 0.15). Treatment success (steers that were never retreated, removed, and/or were a BRD case fatality) ranged from 62.7 to 64.8% between treatments (P = 0.87). There was no evidence to reject the null hypothesis of similar effectiveness between these macrolides when administered to similar steer populations as first-time clinical BRD treatments.

Unveiling Temporal Cyclicities in Seismic b-Values and Major Earthquake Events in Japan by Local Singularity Analysis and Wavelet Methods

Studying the temporal characteristics of earthquake activity contributes to enhancing earthquake prediction capabilities. The seismic b-value is a key indicator describing the relationship between seismic frequency and magnitude. This study investigates the correlation between the occurrence of major earthquakes and seismic b-values using earthquake activity records in Japan from 1990 to 2023. Local singularity analysis and wavelet analysis of earthquake frequency and b-value time series reveal significant 5-year periodic features in seismic activity in Japan. Furthermore, our research identifies that this periodicity is also prominent in major earthquakes with magnitudes of 7 and above. Additionally, through a detailed analysis of the cross-correlation between seismic b-values and the occurrence time of major earthquakes, we uncover a notable pattern: major earthquakes often occur approximately two years after the peak of seismic b-values. This discovery offers a new perspective on earthquake prediction and may play a crucial role in future earthquake early warning systems.

Clinical characteristics of human parvovirus B19 infection after allogeneic stem cell transplantation

Human parvovirus B19 (HPVB19) belongs to Parvoviridae, a genus of erythrovirus, and has been associated with various human diseases, and HPVB19 infection is one of the most important causes of refractory anemia after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study retrospectively analyzed 24 patients with HSCT combined with HPVB19 infection to collate and summarize the clinical presentation, treatment, and regression of patients with combined HPVB19 infection after allo-HSCT and provide experience in the management of HPVB19 infection after allo-HSCT. The median age of the patients with HPVB19 infection was 25 years, and the median time of infection occurrence was +107 days after transplantation, and 22 (91.7% ) had anemia with a median hemoglobin (HGB) level of 77.5 (46-149) g/L, and 13 (54.2% ) had new-onset anemia or persistent decline in HGB. The median length of hospital stay was 19 days. Among patients with new-onset anemia or persistent decline in HGB, the mean increase in HGB after treatment with intravenous immunoglobulin and/or antiviral therapy was 15.69 g/L, and treatment was effective in 10 (76.92% ) patients. HPVB19 infection should be alerted to the development of refractory anemia after HSCT; despite the lack of specific treatment, the overall prognosis of HPVB19-infected patients is good.

Lightning-induced fire regime in Portugal based on satellite-derived and in situ data

Fire databases typically contain information regarding the location, timing, and duration of fire occurrences, as well as the cause (natural or human-induced). These databases allow for the analysis and understanding of the circumstances surrounding the ignition and propagation of wildfires, being highly relevant when addressing fire suppression and management plans, or for improvement of prevention policies. In Portugal, a large number of fires in the official database have unknown causes, which limits the understanding about the relevance of each fire cause, in particular the role of lightning on the ignition of fires over the country. The objective of this paper is twofold: first, we investigated the spatial-temporal variability of lightning-induced fires from 2003 to 2020. Then, we evaluate the feasibility of using remote sensing data as a surrogate for identifying fire causes, through validation with the fire database. Our results revealed that lightning-ignited fires represent an even smaller fraction of all fire events than mentioned in the latest official report about fire causes in the country, accounting for only 1 % of the fire occurrences and 4.6 % of the total burned area in the 18-year period under analysis. The months of June to September comprise 91 % of all lightning fires, which occur more frequently in the northern, remote regions of the country and at relatively high altitudes. Moreover, lightning ignitions originate fires larger than the global average and contributed significantly to the total area burned during the extreme 2003 and 2017 fire seasons. Its importance in these extreme years suggests that lightning can trigger large fires when in conjunction with compound events such as droughts and heatwaves. When compared with in-situ databases, the application of remote sensing data reproduced the seasonality of lightning-ignited fires, but failed to account for the contribution of smaller fires, which represent the majority of occurrences in the Portuguese fire database. Finally, we discuss the implications of our findings for the improved assessment of fire risks, causes, and impacts in Portugal.

A semiconductor wafer manufacturing system scheduling start-up and decision mechanism considering bottleneck drift characteristics

The development of Artificial Intelligence (AI) requires a significant amount of high-performance semiconductor chips. Scientifically and effectively scheduling and optimizing semiconductor wafer manufacturing systems can improve the productivity of the production system, equipment utilization, and semiconductor chip output. Therefore, scheduling optimization and decision-making for semiconductor wafer manufacturing systems have become a hot research topic for current researchers. However, bottleneck drift is an important feature of semiconductor wafer manufacturing systems, and is also a key factor that constrains scheduling and decision-making in semiconductor wafer manufacturing systems. Currently, there is a lack of research on the specific characteristics of bottleneck drift in semiconductor wafer manufacturing systems in the literature, which leads to problems such as ineffective planning and scheduling decisions by managers, and affects the performance of semiconductor wafer manufacturing systems. This paper considers the triggering conditions, occurrence time, and impact on production plan objectives of bottleneck drift, and improves two methods for bottleneck identification and bottleneck drift, based on which a new semiconductor wafer manufacturing systems scheduling start-up mechanism is proposed, which includes three parts and nine steps. Firstly, the semiconductor wafer manufacturing system scheduling process is given, including bottleneck identification, impact analysis, prediction, and planning for the impact of bottleneck drift on production plan objectives. Secondly, bottleneck identification and impact factors are predicted based on bottleneck drift, and the trigger conditions and drift time of bottleneck drift are determined. Then, based on the delivery time of the production plan objectives, the impact of bottleneck drift on production plan objectives is analyzed to determine the scheduling start-up conditions for the semiconductor wafer manufacturing system. Experimental results show that the mechanism proposed in this paper can timely and accurately identify the triggering conditions and drift time of bottleneck drift, avoid ineffective scheduling decisions before bottleneck drift, avoid unnecessary production scheduling decisions, and reduce additional performance losses. In addition, it can analyze the impact of bottleneck drift on production plan objectives according to the production plan objectives, so as to formulate scheduling decision-making schemes better, avoiding production plan delays and waste of production capacity.

Tolerability of the niraparib individualized starting dose in the PRIMA/ENGOT-OV26/GOG-3012 trial of niraparib first-line maintenance therapy

PurposeTo explore safety and tolerability parameters for the niraparib individualized starting dose (ISD) in patients with newly diagnosed advanced ovarian cancer that responded to platinum-based chemotherapy who participated in the phase 3 PRIMA/ENGOT-OV26/GOG-3012 trial (NCT02655016). MethodsThe PRIMA protocol was amended so newly enrolled patients received an ISD based on baseline body weight/platelet count. In this ad hoc analysis, the timing, duration, and resolution of the first occurrence of common any-grade hematologic (thrombocytopenia, anemia, neutropenia) and nonhematologic (nausea, asthenia/fatigue, constipation, insomnia, hypertension) treatment-emergent adverse events (TEAEs) were evaluated by treatment arm in the ISD safety population (data cutoff, November 17, 2021; median follow-up, 3.5 years). ResultsOf 733 randomized patients, 255 were enrolled after the ISD protocol amendment and received ≥ 1 dose of study treatment (niraparib, 169; placebo, 86). In the niraparib arm, median times to first events were 22.0–35.0 days for hematologic TEAEs and 7.0–56.0 days for nonhematologic TEAEs. First events resolved in ≥ 89.8% of patients for hematologic TEAEs; for nonhematologic TEAEs, resolution rates ranged from 55.3% (insomnia) to 86.0% (nausea). Median durations of first hematologic TEAEs were ≤ 16.0 days, but for first nonhematologic TEAEs ranged from 18.0 days (nausea) to 134.0 days (insomnia). ConclusionThe niraparib ISD was generally well tolerated and TEAEs were manageable. Common hematologic and nonhematologic TEAEs occurred early and first events of hematologic TEAEs had a short duration (≈ 2 weeks) and a high resolution rate. These findings support close monitoring immediately following niraparib initiation and may help inform patient expectations for niraparib safety.

Chip-Level Defect Analysis with Virtual Bad Wafers Based on Huge Big Data Handling for Semiconductor Production

Semiconductors continue to shrink in die size because of benefits like cost savings, lower power consumption, and improved performance. However, this reduction leads to more defects due to increased inter-cell interference. Among the various defect types, customer-found defects are the most costly. Thus, finding the root cause of customer-found defects has become crucial to the quality of semiconductors. Traditional methods involve analyzing the pathways of many low-yield wafers. Yet, because of the extremely limited number of customer-found defects, obtaining significant results is difficult. After the products are provided to customers, they undergo rigorous testing and selection, leading to a very low defect rate. However, since the timing of defect occurrence varies depending on the environment in which the product is used, the quantity of defective samples is often quite small. Unfortunately, with such a low number of samples, typically 10 or fewer, it becomes impossible to investigate the root cause of wafer-level defects using conventional methods. This paper introduces a novel approach to finding the root cause of these rare defective chips for the first time in the semiconductor industry. Defective wafers are identified using rare customer-found chips and chip-level EDS (Electrical Die Sorting) data, and these newly identified defective wafers are termed vBADs (virtual bad wafers). The performance of root cause analysis is dramatically improved with vBADs. However, the chip-level analysis presented here demands substantial computing power. Therefore, MPP (Massive Parallel Processing) architecture is implemented and optimized to handle large volumes of chip-level data within a large architecture infrastructure that can manage big data. This allows for a chip-level defect analysis system that can recommend the relevant EDS test and identify the root cause in real time even with a single defective chip. The experimental results demonstrate that the proposed root cause search can reveal the hidden cause of a single defective chip by amplifying it with 90 vBADs, and system performance improves by a factor of 61.

Clinical significance of postoperative complications after pancreatic surgery in time-to-complication and length of postoperative hospital stay: a retrospective study.

We retrospectively analyzed pancreatectomy patients and examined the occurrence rate and timing of postoperative complications (time-to-complication; TTC) and their impact on the length of postoperative hospital stay (POHS) to clarify their characteristics, provide appropriate postoperative management, and improve short-term outcomes in the future. A total of 227 patients, composed of 118 pancreaticoduodenectomy (PD) and 109 distal pancreatectomy (DP) cases, were analyzed. We examined the frequency of occurrence, TTC, and POHS of each type of postoperative complication, and these were analyzed for each surgical procedure. Complications of the Clavien-Dindo (CD) classification Grade II or higher were considered clinically significant. Clinically significant complications were observed in 70.3% and 36.7% of the patients with PD and DP, respectively. Complications occurred at a median of 10 days in patients with PD and 6 days in patients with DP. Postoperative pancreatic fistula (POPF) occurred approximately 7 days postoperatively in both groups. For the POHS, in cases without significant postoperative complications (CD ≤ I), it was approximately 22 days for PD and 11 days for DP. In contrast, when any complications occurred, POHS increased to 30 days for PD and 19 days for DP (each with additional 8 days), respectively. In particular, POPF prolonged the hospital stay by approximately 11 days for both procedures. Each postoperative complication after pancreatectomy has its own characteristics in terms of the frequency of occurrence, TTC, and impact on POHS. A correct understanding of these factors will enable timely therapeutic intervention and improve short-term outcomes after pancreatectomy.

A data-driven and knowledge graph-based analysis of the risk hazard coupling mechanism in subway construction accidents

With the development and expansion of subway construction, accidents usually cause economic losses and seriously threaten personnel safety. Exploring the experience and lessons from accident reports is beneficial for promoting subway construction safety management. Therefore, this study proposes a data-driven and knowledge graph-based approach to reveal the coupling mechanism of risk hazards in subway construction. A total of 231 subway construction accident reports in China from 2001 to 2023 are collected as the database of the knowledge graph. By developing a subway construction safety accident knowledge graph (SCSAKG), the potential paths for accidents can be revealed. To further investigate the internal features of the knowledge graph, topological indicators are proposed to explore the relationships between hazards, hazard types, hazard frequencies, hazard occurrence times, accidents, and accident consequences. Prevention strategies for key risk hazards in subway construction are developed based on the proposed coupling mechanism. The proposed methods that combine knowledge graphs with accident reports can provide decision-making references for subway construction safety management.