1,298 research outputs found
Carbon and nitrogen accumulation and decomposition from coarse woody debris in a naturally regenerated Korean red pine (pinus densiflora S. et Z.) forest
The contribution of coarse woody debris (CWD) to forest carbon (C) and nitrogen (N) dynamics is poorly quantified. This study quantified total C and N content in CWD and estimated the decomposition rates of CWD at different decay stages in a 70-year-old naturally regenerated Korean red pine forest (Pinus densiflora S. et Z.). The N concentration in CWD varied among species and decay classes (from 0.15% to 0.82%), and exhibited a decreasing pattern in C:N ratios with increasing decay class. Total CWD amounts of 4.84 Mg C ha−1, dominated by pine logs (45.4%) and decay class III (40.0%), contained total N of 20.48 kg N ha−1, which was approximately nine times the N input from annual tree mortality. In addition, this study demonstrated that the decay constant rate k was 0.2497 for needle litter, whereas k values were 0.0438, 0.0693, 0.1054, and 0.1947 for red pine CWD of decay class I, II, III, and IV, respectively. The decay rates were significantly related to wood density, N concentration, and C:N ratio across the decay classes of CWD. The results suggest that the C:N ratio of CWD is a key factor affecting its decomposition
Image-Object-Specific Prompt Learning for Few-Shot Class-Incremental Learning
While many FSCIL studies have been undertaken, achieving satisfactory
performance, especially during incremental sessions, has remained challenging.
One prominent challenge is that the encoder, trained with an ample base session
training set, often underperforms in incremental sessions. In this study, we
introduce a novel training framework for FSCIL, capitalizing on the
generalizability of the Contrastive Language-Image Pre-training (CLIP) model to
unseen classes. We achieve this by formulating image-object-specific (IOS)
classifiers for the input images. Here, an IOS classifier refers to one that
targets specific attributes (like wings or wheels) of class objects rather than
the image's background. To create these IOS classifiers, we encode a bias
prompt into the classifiers using our specially designed module, which
harnesses key-prompt pairs to pinpoint the IOS features of classes in each
session. From an FSCIL standpoint, our framework is structured to retain
previous knowledge and swiftly adapt to new sessions without forgetting or
overfitting. This considers the updatability of modules in each session and
some tricks empirically found for fast convergence. Our approach consistently
demonstrates superior performance compared to state-of-the-art methods across
the miniImageNet, CIFAR100, and CUB200 datasets. Further, we provide additional
experiments to validate our learned model's ability to achieve IOS classifiers.
We also conduct ablation studies to analyze the impact of each module within
the architecture.Comment: 8 pages, 4 figures, 4 table
Gain-Scheduled Complementary Filter Design for a MEMS Based Attitude and Heading Reference System
This paper describes a robust and simple algorithm for an attitude and heading reference system (AHRS) based on low-cost MEMS inertial and magnetic sensors. The proposed approach relies on a gain-scheduled complementary filter, augmented by an acceleration-based switching architecture to yield robust performance, even when the vehicle is subject to strong accelerations. Experimental results are provided for a road captive test during which the vehicle dynamics are in high-acceleration mode and the performance of the proposed filter is evaluated against the output from a conventional linear complementary filter
Eosinophilic Otitis Media: CT and MRI Findings and Literature Review
Eosinophilic otitis media (EOM) is a relatively rare, intractable, middle ear disease with extremely viscous mucoid effusion containing eosinophils. EOM is associated with adult bronchial asthma and nasal allergies. Conventional treatments for otitis media with effusion (OME) or for chronic otitis media (COM), like tympanoplasty or mastoidectomy, when performed for the treatment of EOM, can induce severe complications such as deafness. Therefore, it should be differentiated from the usual type of OME or COM. To our knowledge, the clinical and imaging findings of EOM of temporal bone are not well-known to radiologists. We report here the CT and MRI findings of two EOM cases and review the clinical and histopathologic findings of this recently described disease entity
Structural abnormalities in benign childhood epilepsy with centrotemporal spikes (BCECTS)
AbstractPurposeThe aim of this study was to investigate cortical thickness and gray matter volume abnormalities in benign childhood epilepsy with centrotemporal spikes (BCECTS). We additionally assessed the effects of comorbid attention-deficit/hyperactivity (ADHD) on these abnormalities.MethodsSurface and volumetric MR imaging data of children with newly diagnosed BCECTS (n=20, 14 males) and age-matched healthy controls (n=20) were analyzed using FreeSurfer (version 5.3.0, https://surfer.nmr.mgh.harvard.edu). An additional comparison was performed between BCECTS children with and without ADHD (each, n=8). A group comparison was carried out using an analysis of covariance with a value of significance set as p<0.01 or p<0.05.ResultsChildren with BCECTS had significantly thicker right superior frontal, superior temporal, middle temporal, and left pars triangularis cortices. Voxel-based morphometric analysis revealed significantly larger cortical gray matter volumes of the right precuneus, left orbitofrontal, pars orbitalis, precentral gyri, and bilateral putamen and the amygdala of children with BCECTS compared to healthy controls. BCECTS patients with ADHD had significantly thicker left caudal anterior and posterior cingulate gyri and a significantly larger left pars opercularis gyral volume compared to BCECTS patients without ADHD.ConclusionChildren with BCECTS have thicker or larger gray matters in the corticostriatal circuitry at the onset of epilepsy. Comorbid ADHD is also associated with structural aberrations. These findings suggest structural disruptions of the brain network are associated with specific developmental electro-clinical syndromes
Contributing to sustainability education of east asian university students through a field trip experience: A social-ecological perspective
This study reports the effects of a field trip environmental education program with a social-ecological perspective on the experience and learning of university students from China, Japan, South Korea and Vietnam. The students visited Jeju Island, the SaemangeumSeaDike, theDemilitarized Zone and Seoul, South Korea. Their experiences and learning about social-ecological interactions were analyzed using the new environmental paradigmtest, an evaluation questionnaire, group presentations and individual reports. Across demographic characteristics, the participants believed the program fairly presented the concept of social-ecological systems. Some developed new ideas of social-ecological systems through interpreting, transforming and contextualizing their field trip experience based on prior knowledge bases; others compared the sites to case studies. They preferred the sites where social-ecological issues were clearly presented by well-preserved landscapes, successful environmental management or environmental conflict. The results show the need for an advanced multi-dimensional methodology to evaluate students' learning through constructive processes. The program design of this study from planning to field trip and evaluation, the field site design in which regional site resources were organized in a social-ecological context and the analysis of participants' learning and experiences could contribute to attempts to couple the social-ecological perspective with the practice of sustainability and environmental education in field trip design.We appreciate the anonymous private environmental foundation that organized and supported the field trip program. We also appreciate the passionate NGO directors and activists who devoted themselves to helping and guiding the field trip in Jeju, Saemangeum and the DMZ. This study was supported by research grants from the National Research Foundation of Korea (2015R1A6A3A01058445) and the Korea Forest Service (S211216L030120).Scopu
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