• PNF and Movement
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• 제17권3호
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• pp.463-469
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• 2019

Purpose: This study investigated the effect of plantar-flexor muscle fatigue on the force sense and joint reposition sense of ankle joints in the healthy adults. Methods: Fifteen healthy subjects (male: 9, female: 6) participated in this study. A digital dynamometer was used to measure the force sense error while a wireless motion capture device was used to measure the joint reposition sense error. To induce plantar-flexor muscle fatigue for a dominant lower extremity, the subjects were asked to perform plantar flexion until exhaustion while barefoot. The differences in force sense error and joint reposition sense error for the ankle joint were measured immediately. The Wilcoxon test was used to compare these values before and after inducing plantar-flexor muscle fatigue. Results: The force sense error and joint reposition sense error of ankle joints after inducing plantar-flexor muscle fatigue increased significantly compared to the values before inducing muscle fatigue. Conclusion: This study suggests that plantar-flexor muscle fatigue could degrade the force sense and joint reposition sense in ankle joints. In addition, it could deteriorate ankle proprioception.

• Structural Engineering and Mechanics
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• 제54권4호
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• pp.693-710
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• 2015

This paper presents a nonlocal shear deformation beam theory for bending, buckling, and vibration of functionally graded (FG) nanobeams using the nonlocal differential constitutive relations of Eringen. The developed theory account for higher-order variation of transverse shear strain through the depth of the nanobeam, and satisfy the stress-free boundary conditions on the top and bottom surfaces of the nanobeam. A shear correction factor, therefore, is not required. In addition, this nonlocal nanobeam model incorporates the length scale parameter which can capture the small scale effect and it has strong similarities with Euler-Bernoulli beam model in some aspects such as equations of motion, boundary conditions, and stress resultant expressions. The material properties of the FG nanobeam are assumed to vary in the thickness direction. The equations of motion are derived from Hamilton's principle. Analytical solutions are presented for a simply supported FG nanobeam, and the obtained results compare well with those predicted by the nonlocal Timoshenko beam theory.

• Archives of Pharmacal Research
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• 제9권2호
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• pp.111-114
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• 1986

Bretylium tosylate is a quaternary ammonium compound used for the treatment of ventricular fibrilation in humans. It is advantageous to other cationic compound in the study of biliary excretion in that negligible amount is bound to plasma protein and metabolite is not likely is to be formed. Some researchers reported that the formation of ion-pair complex caused to increase the lipothilicity of cationic compound. The partition of bretylium between water and organic phase was increased with the addition of sodium taurodeoxycholate. Also sensitive gas chromatographical assay procedure using flame ionization detector was studied. This procedure can detect as low as 0.1 mg/ml using 0.1 ml biological sample, but contamination by previous injection is the major problem of this method.

• 한국해양공학회지
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• 제23권4호
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• pp.12-18
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• 2009

The present study focused on the compressibility of partially filled fluids in a sloshing tank. Filling ratios ranging from 18% to 26% were used to find compressible impact on a vertical wall. The model test was for 1/25 scale of a 138 K LNGC cargo tank. To investigate the two dimensional phenomenon of sloshing, a longitudinal slice model was tested. A high speed camera was used to capture the flow field, as well as the air pocket deformation. The pressure time history synchronized with the video images revealed the entire compressible process. Three typical impact phenomena were observed: hydraulic jump, flip through, and plunging breaker. In particular, the pressure time history and flow pattern details for flip through and plunging breaker are presented.

• Computers and Concrete
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• 제13권4호
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• pp.569-585
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• 2014

In this paper, a four-layer road structure consisting of an edge transverse crack is simulated using three-dimensional finite element method in order to capture the influence of a single-axle wheel load on the crack propagation through the asphalt concrete layer. Different positions of the vehicular load relative to the cracked area are considered in the analyses. Linear elastic fracture mechanics (LEFM) is used for investigating the effect of the traffic load on the behavior of a crack propagating within the asphalt concrete. The results obtained show that the crack front experiences all three modes of deformation i.e., mode I, mode II and mode III, and the corresponding stress intensity factors are highly affected by the crack geometry and the vehicle position. The results also show that for many loading situations, the contribution of shear deformation (due to mode II and mode III loading) is considerable.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.309-312
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• 2005

21 세기의 핵심기술이 될 가상현실은 차세대를 이끌 주요 패러다임 중 하나로써 광범위한 응용분야를 창출할 수 있고 기술적인 면에서도 커다란 변혁과 전환을 몰고 올 수 있다. 이러한 변화는 앞으로 인간 생활의 전 분야에 있어 그 가치와 파급효과가 매우 커질 것으로 전망된다. 그러나, 국내 가상현실 관련 업체는 대부분 영세한 수준을 벗어나지 못하고 있으며, 업체 간 과다경쟁 및 정보교류의 부족으로 유사 기술에 중복 투자돼 국가적인 손실을 초래하고 있는 것이 현실이다. 따라서 본 연구는 가상현실에 대한 선형연구를 토대로 하여 가상현실 시뮬레이션 시스템을 개발 할 수 있는 방법을 제시하고자 한다.

• 한국운동역학회지
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• 제23권2호
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• pp.141-148
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• 2013

The purpose of this study was to investigate the scapulothoracic joint movement between different weight bearing contributing to effective bench press exercise. Ten male subjects participated in this study. All subjects were tested on the flat bench press machine which modified weight (50% and 70% of 1RM) and subjects were performed two different conditions(none protraction condition and protraction condition). Weight bar height and vertical velocity, EMG activation was measured using 3D motion capture system and wireless EMG analysis system. As the results, none protraction condition showed that it is more concentrate better pectoralis major muscle activation than protraction condition and middle pectoralis major, anterior deltoid and triceps brachii was significant higher integrated EMG in 70% of 1RM condition. In conclusion, limited scapulothoracic joint movement was more effective activated pectoralis major muscle all the weight through, while we could not find that it was not affected integrated EMG on eight muslces related to shoulder complex between scapulothracic joint movement conditions.

• 한국재료학회지
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• 제26권2호
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• pp.90-94
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• 2016

In this study, to increase the strength and enhance the sintering property of $Al_2O_3$, $Y_2O_3$ and $La_2O_3$ were added; the effects of these additions on the sintering characteristics of $Al_2O_3$ were observed. Adding 1% of $Y_2O_3$ to $Al_2O_3$ repressed the development of abnormal particles and reduced the grain boundary migration of $Al_2O_3$, curbing pores to capture particles; as such, the material showed a fine microstructure. But, when over 2% of $Y_2O_3$ was added, the sintering property was reduced because of abnormal particle grain growth and pore formation in particles. Adding 1% of $Y_2O_3$ and $La_2O_3$ to $Al_2O_3$ led to the development of abnormal particles and formed pores in the particles; when over 3% of $La_2O_3$ was added, the sintering property was reduced because the shape of the $Al_2O_3$ particles changed to angled plates.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권5호
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• pp.2194-2210
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• 2018

In the era of big data, consumers capture more and more economic surplus yet the seed of distrust also grows with the fast-spreading of social commerce, this paper began with the idea that product types may determine the degree of consumers' distrust even when identical discounts are offered for those products on Chinese social commerce websites. We also attempted to determine if distrust negatively affected consumers' purchase attitudes. 20 representative products that are commonly sold on social commerce websites in China were chosen to examine the relationships among product types, discount rates, distrust levels, and purchase attitudes. Inductive interview was used to collect the data as well as consumers' perceptions of the relationships. Data analysis results suggested that consumers like deep discounts, but their distrust levels increase along with the discount rates, however, the levels of increasing distrust vary according to product types. High, medium, and low discount rate categorizations were made and three propositions were suggested. This paper will contribute to the body of knowledge on online social commerce market and provide valuable implications for e-retailers and general consumers in online social commerce websites in China.

• Nuclear Engineering and Technology
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• 제53권9호
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• pp.3100-3111
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• 2021

Numerical modeling for the safety-related equipment used in a nuclear power plant (i.e., cabinet facilities) plays an essential role in seismic risk assessment. A full finite element model is often time-consuming for nonlinear time history analysis due to its computational modeling complexity. Thus, this study aims to generate a simplified model that can capture the nonlinear behavior of the electrical cabinet. Accordingly, the distributed plasticity approach was utilized to examine the stiffness-degradation effect caused by the local buckling of the structure. The inherent dynamic characteristics of the numerical model were validated against the experimental test. The outcomes indicate that the proposed model can adequately represent the significant behavior of the structure, and it is preferred in practice to perform the nonlinear analysis of the cabinet. Further investigations were carried out to evaluate the seismic behavior of the cabinet under the influence of the constitutive law of material models. Three available models in OpenSees (i.e., linear, bilinear, and Giuffre-Menegotto-Pinto (GMP) model) were considered to provide an enhanced understating of the seismic responses of the cabinet. It was found that the material nonlinearity, which is the function of its smoothness, is the most effective parameter for the structural analysis of the cabinet. Also, it showed that implementing nonlinear models reduces the seismic response of the cabinet considerably in comparison with the linear model.