• Clinics in Shoulder and Elbow
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• v.18 no.3
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• pp.152-158
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• 2015

Background: Acromioclavicular (AC) stability is maintained through a complex combination of soft-tissue restraints that include coracoclavicular (CC), AC ligament and overlying muscles. Among these structures, the role of the CC ligament has continued to be studied because of its importance on shoulder kinematics, especially after AC injury. This study was designed to determine the geometric change of conoid and trapezoid ligaments and resulting stresses on these ligaments according to various scapular motions. Methods: The scapuloclavicular (SC) complex was isolated from a fresh-frozen cadaver by removing all soft tissues except the AC and CC ligaments. The anatomically aligned SC complex was then scanned with a high-resolution computed tomography scanner into 0.6- mm slices. The Finite element model of the SC complex was obtained and used for calculating the stress on different parts of the CC ligaments with simulated movements of the scapula. Results: Average stress on the conoid ligament during anterior tilt, internal rotation, and scapular protraction was higher, whereas the stress on the trapezoid ligament was more prominent during posterior tilt, external rotation, and retraction. Conclusions: We conclude that CC ligament plays an integral role in regulating horizontal SC motion as well as complex motions indicated by increased stress over the ligament with an incremental scapular position change. The conoid ligament is the key structure restraining scapular protraction that might occur in high-grade AC dislocation. Hence in CC ligament reconstructions involving only single bundle, every attempt must be made to reconstruct conoid part of CC ligament as anatomically as possible.

• Korean Journal of Applied Biomechanics
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• v.21 no.1
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• pp.25-29
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• 2011

The purpose of this study was to analyze quantitative and qualitative differences according to shoe type for the grand jete landing in ballet. The subjects for this study were 9 female ballet majors with an average of 12 years of experience. Subjects jumped, performing a front split, and landed on 1 foot, a movement called the grand jete. Analysis was performed on the students' landing. Independent variables were 3 shoe types: split sole, traditional out sole, and 5-toed forefoot shoes, with bare feet as a control group. Dependent variables were vertical passive ground reaction force and qualitative elements. Passive ground reaction force variables(maximum passive peak value, number of passive peaks, passive force-time integral, and center of pressure) were measured by the Kistler 9281B Force Platform. Qualitative elements were comfort, cushioning, pain, and fit. Statistical analysis included both 1-way ANOVA and Tukey's test for follow-up. Finalized data demonstrated that the 5-toed forefoot shoe allows the forefoot to expand and the toes to individually press down upon landing, increasing foot contact with the surface. Five-toed forefoot shoes minimize passive peaks and pain, while increasing comfort, cushioning, and fit. Most ballet movements are composed of jumping, balancing, landing, and spinning. Wearing 5-toed forefoot shoes allows for a natural range of movement in each toe, to improve both technique and balance. Pain and injuries from ballet can be minimized by wearing the correct shoe type. According to this analysis, it is possible to customized ballet shoes to increase the efficiency of techniques and movements.

• Wind and Structures
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• v.31 no.3
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• pp.269-285
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• 2020

The statistical characteristics of typhoon wind speed records tend to have a considerable time-varying trend; thus, the stationary wind model may not be appropriate to estimate the wind characteristics of typhoon events. Several nonstationary wind speed models have been proposed by pioneers to characterize wind characteristics more accurately, but comparative studies on the applicability of the different wind models are still lacking. In this study, three landfall typhoons, Ampil, Jongdari, and Rumbia, recorded by ultrasonic anemometers atop the Shanghai World Financial Center (SWFC), are used for the comparative analysis of stationary and nonstationary wind characteristics. The time-varying mean is extracted with the discrete wavelet transform (DWT) method, and the time-varying standard deviation is calculated by the autoregressive moving average generalized autoregressive conditional heteroscedasticity (ARMA-GARCH) model. After extracting the time-varying trend, the longitudinal wind characteristics, e.g., the probability distribution, power spectral density (PSD), turbulence integral scale, turbulence intensity, gust factor, and peak factor, are comparatively analyzed based on the stationary wind speed model, time-varying mean wind speed model and time-varying standard deviation wind speed model. The comparative analysis of the different wind models emphasizes the significance of the nonstationary considerations in typhoon events. The time-varying standard deviation model can better identify the similarities among the different typhoons and appropriately describe the nonstationary wind characteristics of the typhoons.

• Nuclear Engineering and Technology
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• v.27 no.3
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• pp.336-343
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• 1995

The Self Tuning Regulator(STR) method which is an approach of adaptive control theory, is ap-plied to design the fully automatic power controller of the nonlinear reactor model. The adaptive control represent a proper approach to design the suboptimal controller for nonlinear, time-varying stochastic systems. The control system is based on a third­order linear model with unknown, time-varying parameters. The updating of the parameter estimates is achieved by the recursive extended least square method with a variable forgetting factor. Based on the estimated parameters, the output (average coolant temperature) is predicted one-step ahead. And then, a weighted one-step ahead controller is designed so that the difference between the output and the desired output is minimized and the variation of the control rod position is small. Also, an integral action is added in order to remove the steady­state error. A nonlinear M plant model was used to simulate the proposed controller of reactor power which covers a wide operating range. From the simulation result, the performances of this controller for ramp input (increase or decrease) are proved to be successful. However, for step input this controller leaves something to be desired.

• Korean Journal of Applied Biomechanics
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• v.29 no.3
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• pp.197-204
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• 2019

Objective: The purpose of this study was to identify the effect of high-heels (HH) modification on metatarsal stress in female workers. Method: Seven females who work in clothing stores ($heights=160.4{\pm}3.9cm$; $weights=47.4{\pm}4.1kg$; $age=31.3{\pm}11.1yrs$; $HH\;wear\;career=8{\pm}6.5yrs$) wore two types of HH (original and modified). The modified HH had been grooved with 1.5 cm radius and 0.2 cm depth around the first metatarsal area inside of the shoes using the modified shoe-last. Participants were asked to walk for 15 minutes on a treadmill and to stand for 10 minutes with original and modified HH, respectively. Kinetics data were collected by the F-scan in-shoe system. After each test, participants were asked to rate their perceived exertion using the Borg's 15-grade RPE scale and interviewed about their feeling of HH. Nonparametric Wilcoxon signed-rank test and effect size (Cohen's d) were used to determine the difference of the variables of interest between the original and modified HH. Results: In the present study, modified HH of the peak contact pressure of 1st metatarsal (PCP) left, PCP right, pressure time integral (PTI) left, peak pressure gradient (PPG) left during standing and PPG right during walking are greater than original HH. And even it didn't show statistically significant, the average in all pressure values of modified HH showed bigger than original HH. It surmised to be related to awkward with modified HH. Even though they said to feel the comfortable cause of big space inside of HH in the interview, they seemed to be not enough time to adapt with new HH. So their walking and standing postures were unstable. Conclusion: Modified the fore-medial part of HH can reduce the stress in the first metatarsal head and big toe area during standing and walking.

• Nuclear Engineering and Technology
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• v.51 no.7
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• pp.1738-1748
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• 2019

Previous research has shown that the inclined condition has an impact on the natural circulation (natural circulation) mode operation of Floating Nuclear Power Plant (FNPP) mounted on the movable marine platform. Due to its compact structure, small volume, strong maneuverability, the Integral Pressurized Water Reactor (IPWR) is adopted as marine reactor in general. The OTSGs of IPWR are symmetrically arranged in the annular region between the reactor vessel and core support barrel in this paper. Therefore, many parallel natural circulation loops are built between the core and the OTSGs primary side when the main pump is stopped. and the inclined condition would lead to discrepancies of the natural circulation drive head among the OTSGs in different locations. In addition, the flow rate and temperature nonuniform distribution of the core caused by inclined condition are coupled with the thermal hydraulics parameters maldistribution caused by OTSG group operating mode on low power operation. By means of the RELAP5 codes were modified by adding module calculating the effect of inclined, heaving and rolling condition, the simulation model of IPWR in inclined condition was built. Using the models developed, the influences on natural circulation operation by inclined angle and OTSG position, the transitions between forced circulation (forced circulation) and natural circulation and the effect on natural circulation operation by different OTSG grouping situations in inclined condition were analyzed. It was observed that a larger inclined angle results the temperature of the core outlet is too high and the OTSG superheat steam is insufficient in natural circulation mode operation. In general, the inclined angle is smaller unless the hull is destroyed seriously or the platform overturn in the ocean. In consequence, the results indicated that the IPWR in the movable marine platform in natural circulation mode operation is safety. Selecting an appropriate average temperature setting value or operating the uplifted OTSG group individually is able to reduce the influence on natural circulation flow of IPWR by inclined condition.

• Physical Therapy Korea
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• v.28 no.2
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• pp.123-131
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• 2021

Background: Only 2% of falls in older adults result in serious injuries (i.e., hip fracture). Therefore, it is important to differentiate injurious versus non-injurious falls, which is critical to develop effective interventions for injury prevention. Objects: The purpose of this study was to a. extract the best features of surface electromyography (sEMG) for classification of injurious falls, and b. find a best model provided by data mining techniques using the extracted features. Methods: Twenty young adults self-initiated falls and landed sideways. Falling trials were consisted of three initial fall directions (forward, sideways, or backward) and three knee positions at the time of hip impact (the impacting-side knee contacted the other knee ("knee together") or the mat ("knee on mat"), or neither the other knee nor the mat was contacted by the impacting-side knee ("free knee"). Falls involved "backward initial fall direction" or "free knee" were defined as "injurious falls" as suggested from previous studies. Nine features were extracted from sEMG signals of four hip muscles during a fall, including integral of absolute value (IAV), Wilson amplitude (WAMP), zero crossing (ZC), number of turns (NT), mean of amplitude (MA), root mean square (RMS), average amplitude change (AAC), difference absolute standard deviation value (DASDV). The decision tree and support vector machine (SVM) were used to classify the injurious falls. Results: For the initial fall direction, accuracy of the best model (SVM with a DASDV) was 48%. For the knee position, accuracy of the best model (SVM with an AAC) was 49%. Furthermore, there was no model that has sensitivity and specificity of 80% or greater. Conclusion: Our results suggest that the classification model built upon the sEMG features of the four hip muscles are not effective to classify injurious falls. Future studies should consider other data mining techniques with different muscles.

• Journal of Preventive Medicine and Public Health
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• v.57 no.2
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• pp.167-175
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• 2024

Objectives: Rural housewives are integral to household management and family care, yet their sedentary lifestyles present significant health risks. This study used the transtheoretical model (TTM) to investigate strategies that encourage and maintain regular exercise habits among rural housewives. Methods: A semi-experimental study was conducted in 2021 with 114 housewives aged 30 to 59 who attended rural health centers in Gorgan, Iran. Participants were randomly assigned to 1 of 2 groups. Data collection involved a validated questionnaire that gathered demographic information and constructs of the TTM. The intervention group participated in a comprehensive educational program, which included four 60-minute sessions. Data were collected again 6 months post-intervention and analyzed using descriptive and inferential statistics in SPSS version 21. Results: The study encompassed women with an average age of 39.75±6.05 years, the majority of whom had educational levels below a diploma, and over 90% were married. We observed strong correlations between the processes of change, self-efficacy, and decisional balance. At the outset, there were no significant differences in demographics or model structures between the 2 groups. However, 6 months post-intervention, the intervention group exhibited statistically significant differences in the mean scores of model structures, stages of change, and body mass index (p<0.05). Conclusions: This study highlights the importance of physical activity training for rural housewives. The findings suggest that the educational intervention, which utilized the TTM, significantly impacted the participants' model structures and their stages of change.

• Journal of Gastric Cancer
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• v.24 no.2
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• pp.137-144
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• 2024

Purpose: Laparoscopic proximal gastrectomy (LPG) is a viable choice for treating proximal gastric lesions. However, the occurrence of severe reflux has limited its widespread adoption. To address this issue, the double flap technique (DFT), which incorporates artificial lower esophageal sphincteroplasty, has been developed to prevent reflux problems after proximal gastrectomy. In this study, we aimed to investigate the usefulness of this technique using high-resolution manometry (HRM), impedance pH monitoring, and esophagogastroduodenoscopy (EGD). Materials and Methods: The findings of pre- and postoperative 6-month HRM, pH monitoring, and EGD were compared for 9 patients who underwent LPG with DFT for various proximal gastric lesions at Incheon St. Mary's Hospital from January 2021 to December. Results: A total of 9 patients underwent proximal gastrectomy. Approximately half of the patients had Hill's grade under II preoperatively, whereas all patients had Hill's grades I and II in EGD findings. In the HRM test, there was no significant difference between distal contractile integral (1,412.46±1,168.51 vs. 852.66±495.62 mmHg·cm·s, P=0.087) and integrated relaxation pressure (12.54±8.97 vs. 8.33±11.30 mmHg, P=0.27). The average lower esophageal sphincter (LES) pressure was 29.19±14.51 mmHg preoperatively, which did not differ from 19.97±18.03 mmHg after the surgery (P=0.17). DeMeester score (7.02±6.36 vs. 21.92±36.17, P=0.21) and total acid exposure time (1.49±1.48 vs. 5.61±10.17, P=0.24) were slightly higher, but the differences were not statistically significant. Conclusions: There is no significant functional difference in HRM and impedance pH monitoring tests after DFT. DFT appears to be useful in preserving LES function following proximal gastrectomy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1542-1547
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• 2008

Physiological activities of the garlic extracts from eight different cultivating areas (three areas from Daejeong Jeju, four major cultivating areas (Danyang, Uiseong, Taean and Namhae) in Korea, and one imported from China) were investigated. Allicin was the highest in the garlic from Danyang (457 mg/100 g), and in the decreasing order of Uiseong (422), Taean (393), China (370), Jeju (334), Namhae (328). Total phenolic content (TPC) from Taean was the highest (3.77 mg GAE/g), while that from Namhae was the lowest (1.90). Average TPC (3.36 mg GAE/g) of the garlics from Daejeong Jeju was higher than that (2.87) from major cultivating areas in Korea. The highest integral antioxidative capacities of water-soluble substance were obtained from the garlics of Danyang ($3.24{\mu}mol$ ascorbic acid equivalents/g) and Daejeong Jeju (2.73), while the lowest ones were from Namhae (1.94) and Taean (1.67). The integral antioxidative capacities of lipid- soluble substance were the highest in the garlics from Namhae ($5.77{\mu}mol$ trolox equivalents/g of dry extract), Danyang (5.31) and Daejeong Jeju (5.29), while the lowest was from Taean (4.19). Average xanthine oxidase inhibition activity (31.1%) in the garlics from Daejeong Jeju was higher than that (23.2%) from major cultivating areas in Korea. All of the garlics showed the strong antimicrobial activity against S. aureus, and in the decreasing order of L. monocytogenes, S. Typhimurium, and E. coli. The garlics from Daejeong Jeju (specially from Alttre) showed the strongest antimicrobial activities against all four bacterial strains tested.