• Title/Summary/Keyword: physical load

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Effect of thermal laser pulse in transversely isotropic Magneto-thermoelastic solid due to Time-Harmonic sources

  • Lata, Parveen;Kaur, Iqbal;Singh, Kulvinder
    • Coupled systems mechanics
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    • v.9 no.4
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    • pp.343-358
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    • 2020
  • The present research deals with the time-harmonic deformation in transversely isotropic magneto thermoelastic solid with two temperature (2T), rotation due to inclined load and laser pulse. Generalized theory of thermoelasticity has been formulated for this mathematical model. The entire thermo-elastic medium is rotating with uniform angular velocity and subjected to thermally insulated and isothermal boundaries. The inclined load is supposed to be a linear combination of a normal load and a tangential load. The Fourier transform techniques have been used to find the solution to the problem. The displacement components, stress components, and conductive temperature distribution with the horizontal distance are computed in the transformed domain and further calculated in the physical domain using numerical inversion techniques. The effect of angle of inclination of normal and tangential load for Green Lindsay Model and time-harmonic source for Lord Shulman model is depicted graphically on the resulting quantities.

A Study on Physical Behavior Property of R/C Beams Strengthened with Bonding Methods (보강재의 부착방법의 따른 물리적 거동 특성에 관한 연구)

  • 한만엽;백승덕
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.727-732
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    • 1999
  • In this research, we made an experiment on the 10 specimen beams that we made. The specimen beams consist of 4 steel plate strengthening beams and 5 carbon fiber sheet strengthening beams. We applied the methods of notch, rounding off a edge, anchor bolt and side shear strengening to the steel plate and for the case of carbon fiber sheet, we applied the methods of anchor bolt, line anchor and shear strengthening. After all the cases were applied, the beams was measured and analyzed about the behavior property of strengthened beams, th ability of strengthening method, the relation between load and the shape of failure, the crack load, the yield load, the shape of crack pattern, the increasing rate from yield load and maximum load and the strain of rebar. All the strengthening methods resulted in almost same value until the yield load, and it wasn't quite different from the theoretical value. In comparison with existing method, the SER, SEAS for the steel plate and the CEA, CESS, CCESS for carbon fiber sheet showed the increasement of ductility with big displacement.

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Effects of Disc Degeneration on Biomechanical Behaviors of the Intevertebral Disc: A Biomechanical Analysis (퇴행성으로 인한 추간판의 생체역학적 거동에 대한 분석)

  • Lee Hyun-Ok;Lee Sung-Jae;Shin Jung-Woog;Shin Tae-Jin
    • The Journal of Korean Physical Therapy
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    • v.12 no.3
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    • pp.455-467
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    • 2000
  • The purpose of this study was to analyse the effects of disc degeneration on the biomechanical behaviors of the intervertebral disc in term of axial displacement, intradiscal pressure. disc bulge at the 1.4-1.5 functional spinal unit(FSU). The degeneration is divided 4 grade by initial intradiscal pressure: normal: 135kPa. mild: 107kPa. moderate: 47kPa, severe: 15kPa, The predicted results were follows: 1. The magnitude of the bulge is found to be maximum at the anterior, minimum at the postero-lateral portion. The bulge of lateral, postero-lateral is found to be maximum in severe grade. followed by moderate. mild, normal grade. 2. Tho displacement was increased with increasing compressive load in all four grades.'rho stiffness of disc was found to be reduced by progressing from normal to severe grade. 3. The intradiscal pressure was increased nearly linearly with increasing compressive load in normal and mild grade. But the increasing rate in moderate and severe grade was showed apparently different from nomal and mild grade. Specially, it was increased very slightly in severe grade. In conclusion, decreased intradiscal pressure resulted in increase of axial displacement and disc bulge with compressive load increasing. these may compromise the nerve root impingement or irritation. Therefore posture and activities must be focus to reduce compressive load applied on the back or disc.

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Physical and mechanical changes on titanium base of three different types of hybrid abutment after cyclic loading

  • Rimantas Oziunas;Jurgina Sakalauskiene;Laurynas Staisiunas;Gediminas Zekonis;Juozas Zilinskas;Gintaras Januzis
    • The Journal of Advanced Prosthodontics
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    • v.15 no.1
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    • pp.33-43
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    • 2023
  • PURPOSE. This study investigated the physical and mechanical changes in the titanium base of three different hybrid abutment materials after cyclic loading by estimating the post-load reverse torque value (RTV), compressive side fulcrum wear pattern of titanium base, and surface roughness. MATERIALS AND METHODS. A total of 24 dental implants were divided into three groups (n = 8 each): Group Z, LD, and P used zirconia, lithium disilicate, and polyetheretherketone, respectively, for hybrid abutment fabrication. RTV was evaluated after cyclic loading with 50 N for 1.2 × 106 chewing cycles. The compressive sides of the titanium bases were analyzed using a scanning electron microscope, and the roughness of the affected areas was measured using an optical profilometer after loading. Datasets were analyzed using Kruskal-Wallis test followed by Mann-Whitney tests with the Bonferroni correction (α = .05). RESULTS. Twenty-three samples passed the test; one LD sample fractured after 770,474 cycles. Post-load RTV varied significantly depending on the hybridabutment material (P = .020). Group P had a significantly higher median of post-load RTVs than group Z (16.5 and 14.3 Ncm, respectively). Groups LD and P showed minor signs of wear, and group Z showed a more pronounced wear pattern. While evaluating compressive side affected area roughness of titanium bases, lower medians were shown in group LD (Ra 0.16 and Rq 0.22 ㎛) and group P (Ra 0.16 and Rq 0.23 ㎛) than in group Z (Ra 0.26 and Rq 0.34 ㎛); significant differences were found only among the unaffected surface and group Z. CONCLUSION. The hybrid abutment material influences the post-load RTV. Group Z had a more pronounced wear pattern on the compressive side of titanium base; however, the surface roughness was not statistically different among the hybridabutment groups.

Effect of the Short Foot Exercise with 2nd~5th Toe Extension on the Abductor Hallucis Activity and Medial Longitudinal Arch under Various Loads (다양한 부하에서 2~5번째 발가락 폄을 동반한 짧은 발 운동이 엄지벌림근 근활성도와 안쪽세로활에 미치는 영향)

  • Seong-in Song;Chang-hwan Bae;Sang-hyun Kim
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.29 no.1
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    • pp.25-31
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    • 2023
  • Background: In this study, the abductor hallucis activity and medial longitudinal arch angle were compared by performing four exercises, namely the short foot exercise, the short foot exercise with 2nd~5th toe extension, the short foot exercise with 2nd~5th toe extension with a load of 1kt on the sole, and the short foot exercise with 2nd~5th toe extension with a load of 2kg on the sole. Methods: Four short foot exercises as described above were performed by 20 healthy adult males and females. The abductor hallucis activity and medial longitudinal arch angle were measured and analyzed by surface electromyography and the Kinovea software program. Results: The short foot exercise with 2nd~5th toe extension, short foot exercise with 2nd~5th toe extension with a load of 1kg on the sole, and the short foot exercise with 2nd~5th toe extension with a load of 2kg on the sole showed significantly higher abductor hallucis activity than the short foot exercise alone. Among these, the short foot exercise with the 2nd~5th toe extension was the most effective. All exercises showed a significantly decreased medial longitudinal arch angle post-exercise than pre-exercise, and the short foot exercise with the 2nd~5th toe extension showed a significantly decreased medial longitudinal arch angle compared to the other three exercises. Conclusion: It is believed that the short foot exercise with the 2nd~5th toe extension can be proposed as an effective exercise that can replace the short foot exercise alone.

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Correlation between cognitive load, vividness and cyber sickness for 360-degree education video

  • Park, Jung Ha
    • International Journal of Advanced Culture Technology
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    • v.8 no.4
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    • pp.89-94
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    • 2020
  • This study attempted to investigate cognitive load, vividness, and cybersickness in nursing students, in the last year of nursing college, who used a 360-degree video content for studying intravenous fluid infusion, one of the core fundamental nursing skills. The aim was to determine the correlation between the variables, and to decide whether the 360-degree video content can be used as an effective supplementary educational material in the regular curricula. This study, a descriptive research, was conducted from October 31, 2019 to November 14, 2019. The participants in this study were 64 students in the 4th year of nursing college at a university located in B City, South Korea. They were instructed to watch a 360-degree video content for intravenous infusion using a Samsung Head Mounted Display (HMD) while ensuring the safety of the students. The results showed that the scores, out of 7 points, for material design, self-evaluation, and physical effort for cognitive load in nursing students were 5.93±0.71, 5.92±0.71, and 5.64±0.74 points, respectively. In addition, the scores, out of 7 points, for mental effort and task difficulty were 2.55±1.08 and 1.94±0.75 points, respectively, and the scores for vividness and cybersickness in the participants were 5.82±0.84, and 2.57±0.98 points, respectively. Physical effort, self-evaluation, and material design for cognitive load in the participants were positively correlated with vividness (r=.379, r=.458, r=.507). In addition, mental effort for cognitive load was positively correlated with cybersickness (r=.684), whereas self-evaluation and material design were negatively correlated with cybersickness (r=-.388, r=-.343). Based on the results of this study, we believe that the 360-degree video content for intravenous fluid infusion can be used as an educational medium in regular and non-regular curricula. In addition, future studies are needed to specifically develop and verify teaching and learning methods on how to apply 360-degree video contents..

A Study on the Load Analysis of Gliding Grade under the Kaltenborn-Evjenth Concept (칼텐본-에비엔즈컨셉 미끄러뜨림 등급의 부하량 크기에 관한 연구)

  • Choi, Seok-Joo;Choi, Wan-Suk;Moon, Ok-Kon
    • Journal of the Korean Society of Radiology
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    • v.6 no.5
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    • pp.383-388
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    • 2012
  • This study attempted to make comparisons in the magnitude of the applied power depending on gender, gliding direction and gliding grade when gliding treatment grade II and III under the Kaltenborn-Evjenth Concept$^{(R)}$ are applied to the caudal, ventral and dorsal shoulder joint using the loading cell equipment. As a result of load difference depending on gender, men showed a significantly higher load than women for all of Caudal Grade II/III, Ventral Grade II/III and Dorsal Grade II/III (p<.05). As a result of comparisons for load difference depending on the treatment direction, the ventral and dorsal loads were significantly higher than the caudal load for all of Grade II and Grade III (p<.05). As a result of comparisons for load difference depending on treatment grade, the load was significantly higher in Grade III than Grade II for all of the caudal, ventral and dorsal side (p<.05). Given the aforesaid results, it could be confirmed that the magnitude of the applied force at the same grade could be different depending on the direction and gender, when gliding II/III are applied to the caudal, ventral and dorsal of glenohumeral joint.

Load Modeling of the Drum Washing Machine Considering the Mechanical Characteristics (역학적 특성을 고려한 드럼세탁기 부하 모델링)

  • Lee, Jung-Hyo;Lee, Won-Chul;Yu, Jae-Sung;Jung, Yong-Chae;Won, Chung-Yuen
    • The Transactions of the Korean Institute of Power Electronics
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    • v.12 no.6
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    • pp.491-499
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    • 2007
  • The variation of a load characteristic in the motor drive is one of the most important consideration. Because the current flowing into the motor generally varies according to the load variation, it needs to design the motor drive circuit properly in accordance with the load variation. However, the load variation of the drum washing machine is irregular and large due to the water flow and reverse load torque. Therefore, to design the motor drive circuit considering this load pattern, simulation results shows the load pattern modeling of the drum washing machine based on the physical analysis in this paper.

Numerical investigations of pile load distribution in pile group foundation subjected to vertical load and large moment

  • Ukritchon, Boonchai;Faustino, Janine Correa;Keawsawasvong, Suraparb
    • Geomechanics and Engineering
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    • v.10 no.5
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    • pp.577-598
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    • 2016
  • This paper presents a numerical study of pile force distribution in a pile group foundation subjected to vertical load and large moment. The physical modeling of a pile foundation for a wind turbine is analyzed using 3D finite element software, PLAXIS 3D. The soil profile consists of several clay layers, which are modeled as Mohr-Coulomb material in an undrained condition. The piles in the pile group foundation are modeled as special elements called embedded pile elements. To model the problem of a pile group foundation, a small gap is created between the pile cap and underlying soil. The pile cap is modeled as a rigid plate element connected to each pile by a hinge. As a result, applied vertical load and large moment are transferred only to piles without any load sharing to underlying soil. Results of the study focus on pile load distribution for the square shape of a pile group foundation. Mathematical expression is proposed to describe pile force distribution for the cases of vertical load and large moment and purely vertical load.

Efficient Virtual Machine Placement Considering System Load (시스템 부하를 고려한 효율적인 가상 머신 배치)

  • Jung, Sungmin
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.16 no.2
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    • pp.35-43
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    • 2020
  • Cloud computing integrates computing resources such as servers, storage, and networks with virtualization technology to provide suitable services according to user needs. Due to the structural characteristics of sharing physical resources based on virtualization technology, threats to availability can occur, so it is essential to respond to availability threats in cloud computing. Existing over-provisioning method is not suitable because it can generate idle resources and cause under-provisioning to degrade or disconnect service. System resources must be allocated in real-time according to the system load to guarantee the cloud system's availability. Through appropriate management measures, it is necessary to reduce the system load and increase the performance of the system. This paper analyzes the work response time according to the allocation or migration of virtual machines and discusses an efficient resource management method considering the system load.