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In open-air explosion experiments, the measured blast pressure characteristics often show high Coefficients of Variation (COV), causing reproducibility issues. Shock tubes can address this problem. They consist of a driver section, where the shock is generated, and a driven section, where it is transmitted. The shock can be produced using either gas or high explosives (HEs). The intensity of gas-generated shocks are limited due to the driver section’s size, making HE-based shock tubes more suitable for replacing open-field detonation tests. This study derived experimental conditions for an HE-based shock tube to replicate the pressure characteristics from open-air experiments. Conditions include the sealed status of the driver section, TNT location and amount, expansion tube presence, and target location. When TNT was centered at the driver section and the driver section was sealed, reflections caused the peak pressure to occur twice, which is unsuitable for target loading. The COV values of reflected pressures at different locations of target were high without target contact but dropped significantly with contact, showing that target contact with the shock tube is necessary for uniform pressure generation. Additionally, it was confirmed that using the expansion section also resulted in low COV values for both reproducibility and uniform pressure.

Quantifying structural brain changes is critical for diagnosing and monitoring neurodegenerative diseases. Although magnetic resonance imaging (MRI) is the silver standard, limited accessibility and cost hamper routine use. We developed a deep learning–based framework using the nnU-Net for brain segmentation using computed tomography (CT) to assess cerebrospinal fluid (CSF) volume changes, as an indirect marker of tissue loss, and evaluated its utility across Alzheimer’s disease (AD) stages and frontotemporal dementia (FTD) subtypes. We included 2357 participants: cognitively unimpaired (CU, n = 595), mild cognitive impairment (MCI, n = 954), dementia of Alzheimer’s type (DAT, n = 663), and FTD subtypes (FTD, n = 145, behavioral variant FTD (bvFTD, n = 66), nonfluent variant primary progressive aphasia (nfvPPA, n = 29), and semantic variant PPA (svPPA, n = 50). CT-based segmentation was trained and validated using 3D T1-weighted MRI as reference. We assessed (1) segmentation accuracy via Dice similarity coefficients (DSCs), (2) reliability and precision using correlation and Bland–Altman analyses, and (3) clinical utility by identifying stage- and region-specific changes in CSF volumes. Key regions, including anterior and posterior lateral ventricles, showed DSCs above 0.93 and correlations ranging from 0.822 to 0.996. CT-based measurements revealed increasing CSF volumes from CU to DAT and distinct patterns of CSF volume enlargement across FTD subtypes. This framework enables accurate, reliable assessment of CSF volume changes as an indirect marker of atrophy, and supports early detection and differential diagnosis.

We aimed to assess cross-cultural differences in depressive symptoms and the validity of the Korean version of the Mood and Feelings Questionnaire (MFQ). Four hundred and sixty-four children and adolescents (aged 7–19, 278 girls) with any psychiatric diagnosis, 290 of whom had major depressive disorder, were included. The levels of depressive symptoms in children and adolescents were evaluated by children/adolescents and their parents. We conducted Pearson’s r and Cronbach’s α, confirmative factor analysis and item response theory tests. The Korean version of the MFQ demonstrated excellent criterion validity and discriminant validity. There were no cultural differences in the clinical manifestations of depression in youth from Western countries and Korea. Korean youths with depression were more likely to complain of cognitive and emotional symptoms than somatic symptoms. The Korean version of the MFQ demonstrated promising psychometric properties in a clinical sample of children and adolescents.

Bid-rigging has long been a problem in the construction area. This research identified the existing problems in evaluating damages from bid-rigging in Design-Bid-Build (DBB) and lowest-bid construction projects. Traditional econometric assessment based on stochastics requires sufficient historical data to obtain reliable estimates. Thus, it is crucial to collect and analyze data from pertinent projects for its utilization. To ensure the accuracy of the estimation, a substantial amount of data on the outcomes of DBB bids should have been gathered. In many construction projects, that requirement could not be met. Furthermore, econometric analysis cannot reflect the differences caused by the details of individual projects. This study proposes an alternative approach based on detailed cost estimates, weights of major work groups and their historical bid rates when historical data from similar projects are scarce. This approach can reflect the distinct characteristics of individual projects. The proposed model was applied to 23 gas pipeline construction projects under DBB and the lowest bid. This study identified the impacts of the different compositions of major work groups. Bid rates of the main work groups could not only be used to evaluate the damages caused by bid-rigging, but could also be used to determine reliable bid prices and provide a bidding strategy to aid the bidder’s decision-making process in future bids for similar projects.

Endometriosis, which is the presence of endometrial stroma and glands outside the uterus, is one of the most frequently diagnosed gynecologic diseases in reproductive women. Patients with endometriosis suffer from various pain symptoms such as dysmenorrhea, dyspareunia, and chronic pelvic pain. The pathophysiology for chronic pain in patients with endometriosis has not been fully understood. Altered inflammatory responses have been shown to contribute to pain symptoms. Increased secretion of cytokines, angiogenic factors, and nerve growth factors has been suggested to increase pain. Also, altered distribution of nerve fibers may also contribute to chronic pain. Aside from local contributing factors, sensitization of the nervous system is also important in understanding persistent pain in endometriosis. Peripheral sensitization as well as central sensitization have been identified in patients with endometriosis. These sensitizations of the nervous system can also explain increased incidence of comorbidities related to pain such as irritable bowel disease, bladder pain syndrome, and vulvodynia in patients with endometriosis. In conclusion, there are various possible mechanisms behind pain in patients with endometriosis, and understanding these mechanisms can help clinicians understand the nature of the pain symptoms and decide on treatments for endometriosis-related pain symptoms.

The market for electric vehicles is growing rapidly. Among them, the demand for a dual motor type 4 WD (Four -Wheel Driving) system is increasing. In this paper, we present the Torque Matching Strategy (TMS) method to select the optimal torque distribution ratio for dual motors. The TMS controller operates to set the optimal efficiency point by linearizing the drive efficiency combination of the two motors. Driving simulation and testing were performed through five drive cycles in the driver model interworking environment implemented in MATLAB and Carsim. The optimal distribution ratio was derived according to the front and rear gear ratios under the load condition, and the driving was verified by comparing it with the TMS control method. The efficiency was numerically verified by comparing the power loss of the driving motor. It reduced up to 34% in Urban Dynamometer Driving Schedule and up to 56.3% in Highway fuel efficiency test. The effectiveness of the TMS control method was demonstrated through the distribution rate trend based on the operation cycle and power loss.

Frontotemporal dementia (FTD) encompasses heterogeneous clinical syndromes, and distinguishing its subtypes using imaging remains challenging. We developed a deep learning model to quantify brain atrophy by measuring cerebrospinal fluid (CSF) volumes in key regions of interest (RoIs) on standard MRI scans. In a retrospective study, we analyzed 3D T1-weighted MRI data from 1,854 individuals, including cognitively unimpaired (CU) controls, patients with dementia of the Alzheimer type (DAT), and FTD subtypes: behavioral variant FTD (bvFTD), nonfluent variant primary progressive aphasia (nfvPPA), and semantic variant PPA (svPPA). The model quantified CSF volumes in 14 clinically relevant RoIs and generated age- and sex-adjusted W-scores to express regional atrophy. Each FTD subtype exhibited a distinct, lateralized atrophy pattern: bvFTD showed widespread bilateral frontal and right-predominant parietal and temporal atrophy; nfvPPA showed left-predominant frontal and parietal atrophy; and svPPA exhibited marked left-lateralized temporal and hippocampal atrophy. All FTD subtypes demonstrated significantly greater CSF expansion in these characteristic regions compared to DAT and CU. This deep learning approach provides a simple, interpretable measure of brain atrophy that differentiates FTD subtypes, requiring only standard MRI with minimal preprocessing, and offers clinical utility.

The demand for advanced packaging is driven by the need for low-profile, densely-integrated, large-die Si devices in substrate-based or wafer-level packaging. Die strength is a critical parameter for ultrathin dies, making die singulation a vital aspect of advanced packaging technology. In this work, we present a dicing before grinding (DBG) process to compare and analyze die strengths using a mechanical blade, stealth laser, and plasma dicing. The three DBG processes were applied to a 200 mm silicon (Si) wafer process with a die size of 10 × 10 mm2 and thicknesses of 100, 200, and 300 μm, respectively. Optical and electron microscopes were employed to investigate chipping quality, sidewall damage, and surface contamination. The bare Si die’s strength was assessed using a three-point bending test. Plasma dicing before grinding (PDBG) resulted in less contamination, chipping, and cracking compared to other DBG processes. Furthermore, PDBG exhibited the highest die strength of 1052 Pa.

Most construction projects are delayed, and many are subject to claims or disputes. Therefore, delay analysis is a critical component of any construction project to determine who is responsible for delays. This research examines four different techniques for estimating delay impacts using the impacted as-planned (IAP) method. A sample network was introduced as an example to discuss several concerns. The advantages and limitations of each approach were identified, and recommendations were given for each approach. When inserting an activity or activities representing delay events in IAP, it is necessary to use both constraints and logical relations among delay events, their logical predecessors, and successors. Constraints representing the actual date of delay events are the simplest and easiest. However, constraints should not be used in “single insertion” and “inserting only owner- or contractor-caused delay” approach. In addition, in the case of using constraints, it is critical to ensure that the impact of delay events is less than the duration of those delay events. Constraints should be avoided in this scenario, and delay events should be logically connected to their logical predecessors and successors without constraints. This study also identified through an example that inserting delay events only by logic can cause wrong analysis results. The results of this study will be helpful for delay analysts in identifying what kinds of problems occur in IAP methods and how to prevent those problems.

Let f be a positive definite integral quinary quadratic form and let r ( n ,  f ) be the number of representations of an integer n by f . A quinary quadratic form f is said to be a Bell quinary quadratic form if f is isometric to x 1 2 + 2 α x 2 2 + 2 β x 3 2 + 2 γ x 4 2 + 2 δ x 5 2 for some nonnegative integers α , β , γ , δ . In this article, we reprove the result of Bell (Am J Math 52:271–279, 1930) and compute r ( n ,  f ) by using the number of representations of the sum of 5 squares for any Bell quinary quadratic form f with class number 2.