2,201 research outputs found

    A Proposal of Storytelling Direction as a Process of Narrowing the Gap between Designers and Users

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    OAIID:RECH_ACHV_DSTSH_NO:A201701933RECH_ACHV_FG:RR00200003ADJUST_YN:EMP_ID:A080155CITE_RATE:FILENAME:HCIK2017_디자이너와 사용자의 간극을 좁히는 프로세스로서 스토리텔링 방향성 제안_paper_242_FINAL.pdfDEPT_NM:디자인학부EMAIL:[email protected]_YN:FILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/b8b39b27-ce50-4d0f-b403-08849291b068/linkCONFIRM:

    Identification of the optimal hiit protocol for fatigue resistance in adolescent athletes: a randomized controlled trial

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    The combat sports athletes developed great gains in both muscular function and fatigue resistance by utilizing high-intensity interval training (HIIT). However, it has not been investigated fully whether different work-to-rest ratios of HIIT show the effectiveness on muscle function in adolescent athletes. The purpose of the study was to compare different work-to-rest ratios by applying different rest times in response to the identical work time during HIIT on muscle function in adolescent taekwondo athletes. Forty-seven adolescent male taekwondo athletes (mean age: 16.7±0.8 years) were randomly assigned to the control group (n=11) vs. three HIIT groups by work-to-rest ratios; (1) 1:2 [30s:60s] (n=12), (2) 1:4 [30s:120s] (n=12), and (3) 1:8 [30s:240s] (n=12). All groups completed 10 experimental sessions over four weeks, while the control group maintained their regular taekwondo training. Muscular functions were measured by assessing isokinetic muscle strength and endurance of the knee extensor and flexor. The participants performed three sets of twenty maximal extension and flexion contractions at 120°s-1 with a 1-min interval between the sets for fatigue resistance. Blood samples were collected to measure free-testosterone, cortisol, creatine kinase, and urea as stress-to-recovery indicators. A positive effect on improving muscle fatigue resistance was observed at the first set of assessments in the HIIT with 1:4 (Δ10.2%, p<.05) and 1:8 groups (Δ8.6%, p<.05). Additionally, the 1:4 group exhibited fatigue resistance improvement in the second set (Δ7.7%, p<.01) without any changes of stress-to-recovery indicators, while the other groups did not show any improvement. The 30s all-out work with 120s rest time, lasting over a brief 4-week period, improved participants’ fatigue resistance. A certain amount of rest time between high-intense movements is required to optimize muscle development in adolescent athletes compared with insufficient rest time

    Vitamin D3 Supplementation Reduces the Symptoms of Upper Respiratory Tract Infection during Winter Training in Vitamin D-Insufficient Taekwondo Athletes: A Randomized Controlled Trial

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    Vitamin D insufficiency may be associated with increased risk of upper respiratory tract infection (URTI) in athletes. This study examined the effects of vitamin D3 supplementation on salivary immune functions and symptoms of URTI in vitamin D-insufficient taekwondo athletes. Twenty-five male taekwondo athletes, aged 19–22 years with vitamin D insufficiency [serum 25-hydroxyvitamin-D concentrations (25(OH)D, 31.3 ± 1.39 nmol/L)], participated in this study. They were randomized to receive 5000 IU/day of vitamin D3 (n = 13) or placebo capsule (n = 12) during 4 weeks of winter training. Blood samples were collected two times (pre- and post-tests) for analyzing serum 25(OH)D concentration while salivary samples were obtained three times (pre-, mid-, and post-tests) for secretory immunoglobulin A (SIgA) and lactoferrin analyses. The symptoms of URTI were reported daily during the intervention. Serum 25(OH)D concentration significantly increased by 255.6% in the vitamin D group, whereas in the placebo group it did not change (p \u3c 0.001). While the significant increase in SIgA was observed in both groups (p \u3c 0.001), elevated salivary lactoferrin level in response to winter training was found only in the placebo group (p = 0.011). The change in serum 25(OH)D concentration was negatively associated with total URTI symptoms (r = −0.435, p = 0.015). Vitamin D3 supplementation may be effective in reducing the symptoms of URTI during winter training in vitamin D-insufficient taekwondo athletes

    Elevated fasting insulin predicts the future incidence of metabolic syndrome: a 5-year follow-up study

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    <p>Abstract</p> <p>Background</p> <p>There is controversy about the specific pathophysiology of metabolic syndrome (MS) but several authors have argued that hyperinsulinemia is a key feature of the cluster. We aimed to assess whether the baseline insulin levels could predict the development of MS in a well characterised cohort of otherwise healthy adults who were followed over a five year period.</p> <p>Methods</p> <p>We identified 2, 350 Koreans subjects who did not have MS in 2003 and who were followed up in 2008. The subjects were divided into 4 groups according to the baseline quartiles of fasting insulin, and the predictors of the incidence of MS were analyzed using multivariate regression analysis.</p> <p>Results</p> <p>Over the follow up period, 8.5% of the cohort developed MS. However, 16.4% of the subjects in the highest quartile of the insulin levels developed MS. In a model that included gender, age, the smoking status, the exercise level, alcohol consumption and the systolic blood pressure, the subjects in the highest quartile of the insulin levels had more than a 5 times greater risk of developing MS compared that of the subjects in the lowest quartile. This predictive importance remained significant even after correcting for all the individual features of MS.</p> <p>Conclusions</p> <p>These data suggest that high baseline fasting insulin levels are independent determinants for the future development of MS.</p

    M3FPolypSegNet: Segmentation Network with Multi-frequency Feature Fusion for Polyp Localization in Colonoscopy Images

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    Polyp segmentation is crucial for preventing colorectal cancer a common type of cancer. Deep learning has been used to segment polyps automatically, which reduces the risk of misdiagnosis. Localizing small polyps in colonoscopy images is challenging because of its complex characteristics, such as color, occlusion, and various shapes of polyps. To address this challenge, a novel frequency-based fully convolutional neural network, Multi-Frequency Feature Fusion Polyp Segmentation Network (M3FPolypSegNet) was proposed to decompose the input image into low/high/full-frequency components to use the characteristics of each component. We used three independent multi-frequency encoders to map multiple input images into a high-dimensional feature space. In the Frequency-ASPP Scalable Attention Module (F-ASPP SAM), ASPP was applied between each frequency component to preserve scale information. Subsequently, scalable attention was applied to emphasize polyp regions in a high-dimensional feature space. Finally, we designed three multi-task learning (i.e., region, edge, and distance) in four decoder blocks to learn the structural characteristics of the region. The proposed model outperformed various segmentation models with performance gains of 6.92% and 7.52% on average for all metrics on CVC-ClinicDB and BKAI-IGH-NeoPolyp, respectively.Comment: 5pages. 2023 IEEE International Conference on Image Processing (ICIP). IEEE, 202

    Photocatalytic Activity of Titanate Nanotube Powders in a Hybrid Pollution Control System

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    The photocatalytic activity on decomposition of Rhodamine B (RB) of titanate nanotubes (TNTs) synthesized by alkali hydrothermal treatment method was evaluated using a microwave/UV/photocatalyst hybrid system. The effects of each element technique as well as the synergy effects on decomposition of organic material were investigated. When TNTs were ion-exchanged with HCl, Na+ content was reduced from 8.36 wt% to 0.03 wt%, whereas the TNTs calcined at 723 K was phase-transformed into anatase structure. The RB decomposition rate increased with TNTs dosage as well as with microwave intensity. Effect of addition of auxiliary oxidants on photocatalytic decomposition of RB was also investigated. When ozone was added, the decomposition rate increased with the amount of ozone added. When H2O2 was used as the auxiliary oxidant, however, addition of H2O2 exceeding a threshold amount caused reduction of decomposition rate. A synergy effect was observed when H2O2 addition was combined with microwave-assisted photocatalysis

    Determining the influence of ship hull deformations caused by draught change on shaft alignment application using FE analysis

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    This paper was to address the shortcomings of current design practice to evaluate the stability of the shaft alignment for a 300,000 DWT Very Large Crude Oil Carrier. An enhanced approach using FE was applied to identify the influence of hull deformation on the alignment of the shafting system. The effectiveness of this method was demonstrated in comparison with Jack up technique. Analysis results showed that the hull deformation could be a key factor affecting the offset distortion of each bearing supporting the shaft line. Moreover, it was confirmed that the deformation pattern of cargo hold was opposite to the deformation of engine room structure when hull deformation occurred due to draught change of the case ship. As new research findings, they are believed to contribute significantly to the prevention of shaft damage associated with hull deformations, thereby improving the reliability of shaft alignment for similar types of vessels

    Comparisons of physique, body composition, and somatotype by weight division between male and female collegiate taekwondo athletes

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    The aim of the study was to compare the physique, body composition and somatotype between male and female collegiate taekwondo athletes and specially focus on differences by weight division. 60 collegiate taekwondo athletes (male: 29, female: 31) voluntarily participated in the study. They were divided into four Olympic weight divisions (male for -58 kg, -68 kg, -80 kg, +80 kg, female for -49 kg, -57 kg, -67 kg, +67 kg). Anthropometric measurements included body weight, height, sitting height, body circumferences (relaxed arm, flexed arm, chest, waist, hip, thigh, and calf), bone widths (humerus and femur), and skinfold thicknesses (triceps, subscapular, suprailiac, thigh, and calf) were measured. The three somatotype components were assessed by Heath-Carter anthropometric method (Carter & Heath, 1990). Independent t-test and one-way ANOVA were applied to analyze difference of dependent variables. Significant level was set at .05. Male athletes were taller and heavier than female athletes. However, sum of skinfold thickness was significantly higher in female athletes than male athletes. The three somatotype components for male athletes were 3.4-3.5-3.1 and characterized with balanced mesomorphy. On the other hand, the somatotype of female athletes were 6.1-3.4-2.6 and characterized with mesomorphic endomorph. In male athletes -80 kg and +80 kg weight divisions were higher mesomorphy, but lower ectomorphy than -58 kg and -68 kg weight divisions. In female, -57 kg, -67 kg and +67 kg weight divisions were higher endomorphy and mesomorphy, but lower ectomorphy than -49 kg weight divisions. In conclusion, male athletes had higher anthropometric characteristics than female athletes except for the skinfold thickness. Female athletes had higher endomorphy, whereas male athletes had higher ectomorphy. Physique and somatotype were different between weight divisions both male and female athletes. This study provides a reference data of morphological characteristics of collegiate elite taekwondo athletes
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