• 한국환경복원기술학회지
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• 제7권2호
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• pp.46-51
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• 2004

In this paper, reinforcement of soil shear strength by bamboo(substitute materials simulating a root system) are evaluated by soil strength parameters(apparent cohesion(c) and internal friction angle(tan${\Phi}$)), using simple shear tester which clearly depicts shear deformation and controls soil suction. The results show that the internal friction angle does not change under various soil suction conditions but the apparent cohesion, which reach a peak in suction of 45cm$H_2O$ near critical capillary head, is effected by soil suction. And the reinforcement of soil strength by bamboo are expressed by apparent cohesion more than internal friction angle. In addition the increment of apparent cohesion by bamboo reached a peak in suction 45cm$H_2O$ too.

• 한국전문물리치료학회지
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• 제30권1호
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• pp.15-22
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• 2023

Background: Delivery workers repeatedly get in and out of trucks and walk or run to deliver packages during work. Iliotibial band syndrome (ITBS) is a well-known non-traumatic overuse injury of the lateral side of the knee caused by frequent knee flexion and extension. Hip muscle strength is among the factors that prevent lower extremity injuries. Although many studies have examined the relationship between ITBS and hip muscle strengths, there was no study comparing hip muscle strength and ratio between delivery workers with and without ITBS. Objects: This study aimed to compare hip muscle strength and hip internal/external rotator and adductor/abductor strength ratios between delivery workers with and without ITBS. Methods: Fourteen delivery workers with ITBS matched inclusion criteria in the present study among 20 participants. Because total sample size was required 28 subjects by G*power program (ver. 3.1.9.4; University of Trier), 14 delivery workers without ITBS were recruited. Hip muscle strengths were measured in a side-lying position using a Smart KEMA pulling sensor (KOREATECH Co. Ltd.). An independent t-test was used to compare hip muscle strengths and hip internal/external rotator and hip adductor/abductor strength ratios between delivery workers with and without ITBS. Results: The adductor/abductor strength ratio was significantly greater in delivery workers without ITBS than in those with ITBS (p < 0.05). The strengths of the hip abductor, hip adductor, hip internal rotator, hip external rotator, and the ratio of internal/external rotator strengths were not significantly different between the delivery workers with and without ITBS (p > 0.05). Conclusion: This study's findings showed that delivery workers with ITBS had significantly lesser adductor/abductor strength ratio, while the strengths of the hip abductor and adductor muscles did not differ significantly. These results suggest that adductor/abductor strength ratio should be considered when evaluating and treating ITBS in delivery workers.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.26-27
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• 2014

Study on high temperature properties of concrete and internal force estimation of structural member subjected to high temperature mainly applied high temperature strength model based on experimental results with concrete under 40MPa. However, it is reported that degradation of internal force at high temperature and spalling of ultra high strength concrete are higher than that of normal strength concrete. Therefore, this study attempts to propose compressive strength degradation model which is suitable to ultra high strength concrete comparing to existing model by evaluating high temperature properties of ultra high strength concrete.

• 펄프종이기술
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• 제31권1호
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• pp.46-51
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• 1999

The most important effect of refining is believed as the internal fibrillation. The internal fibrillation is the separation of the fiber wall into several lamellae. The internal fibrillation results in fiber swelling as water penetrates the fiber wall. The increase in paper strength as a result of refining was due to delamination which made the fiber more flexible. Pulp fibers are refined to 20, 40, and 70$^{\circ}$SR freeness at Valley beater. Changes of Physical paper properties are analyzed depending on fiber wall thickness and fiber's collapse index at 2.5 and 5.6kg$_f$ refining load. At same $^[\circ}$SR freeness with 2.5kg$_f$ refining load, fiber wall thickness is increased further than at high 5.6kg$_f$ refining load. With higher fiber wall thickness by lower intensity refining load, higher internal fibrillation, flexibility, collapsability of fibers are achieved. Those effects improve WRV, tensile strength, and burst strength. Tear strength shows opposite trend to tensile and burst strength as usual.

• 동아시아경상학회지
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• 제12권1호
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• pp.1-11
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• 2024

Purpose: This study empirically examines the relations among corporate performance, technology, and corporate capabilities for service companies to find factors that could affect the competitiveness of the service industry. Most study on technology in the service industry have been conducted in developed countries, and yet there exist not sufficient empirical reviews. Research design, data and methodology: This paper, using rare empirical data, examines Korea's service industry and aims to make an academic and managerial contribution to the understanding of the relation between corporate competence and performance. This study analyzes 567 Korean Domestic Companies in Non-manufacturing and Service Industry, using the 2020 Detailed Survey of Venture Businesses (2500) data. Frequency analysis, correlation analysis, and regression analysis are performed. Results: Results show, Hypothesis 1 that internal competence has positive influence on technological strength, is supported. However, Hypothesis 2 that technological strength mediates between internal competence and business performance, Hypothesis 3 that external competence has positive influence on technological strength and Hypothesis 4 that technological strength mediates between external competence and business performance are all partially supported/rejected. Conclusions: This study suggests that technological strength is an important factor that affects both market share and sales. And mediating effect of technology strength emphasized in market share. However, in managing sales, more cautious approach and a more detailed analysis are needed..

• 한국지반공학회논문집
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• 제36권2호
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• pp.17-28
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• 2020

본 연구에서는, 제주도 화산암의 인장강도와 관련하여, 기존의 연구결과 및 본 연구에서 수행된 시험결과에 대한 종합적인 비교·분석을 수행하였으며, 제주도 화산암의 압열인장강도와 일축압축강도로부터 추정된 점착력과 내부 마찰각의 특성 및 그 유효성을 각각 살펴보았다. 제주도 화산암의 압열인장강도는 흡수율과 밀접한 관계에 있었으며, 흡수율이 증가함에 따라 지수 함수적으로 급격하게 감소하는 특성을 갖고 있었다. 내부 마찰각은 압열인장도강도에 대한 일축압축강도의 비(σ_c / σ_t)와 밀접한 관계에 있었으며, 강도비 σ_c / σ_t가 증가함에 따라 내부 마찰각은 로그 함수적으로 증가하는 특성을 갖고 있었다. 그리고 제주도 화산암의 강도비 σ_c / σ_t는 내부 마찰각의 크기에 따라 약 5~20 사이의 값을 나타내고 있었다. 한편, 점착력(c)의 경우, 흡수율 및 압열인장강도와 밀접한 관계에 있음을 확인할 수 있었다. 점착력과 흡수율 사이에는 압열인장강도와 흡수율의 관계와 같이 지수 함수적인 관계에 있으며, 점착력과 압열인장강도 사이에는 선형관계에 있음을 확인할 수 있었다. 그리고 일축압축강도와 압열인장강도로부터 추정된 내부 마찰각과 점착력은 각각 삼축압축강도로부터 추정된 내부 마찰각과 점착력에 비해 약 13% 과소평가 그리고 약 24% 정도 과대평가되는 경향을 보였다.

• Clinics in Shoulder and Elbow
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• 제17권4호
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• pp.166-174
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• 2014

Background: Our study was to determine the effect on shoulder isokinetic muscle strength and muscle endurance in isolated full-thickness supraspinatus tendon tear and combined other rotator cuff tear. Methods: Total of 81 male patients (mean age $57.8{\pm}7.4$ years) who were diagnosed as a full-thickness supraspinatus tendon tear were included. They were classified into isolated or combined tear. The isokinetic muscle strength and muscle endurance were measured using the Biodex multi-joint system $PRO^{(R)}$ (Biodex Medical Systems, Shirley, NY, USA) in following movements: shoulder abduction, adduction, flexion, extension, external rotation, and internal rotation. Then, the difference in muscle function according to the type of tears were assessed. Fifty-seven patients had isolated supraspinatus tendon (mean age $56.9{\pm}7.3$ years). They were classified into either anteroposterior tear or modified mediolateral tear. The size were measured using T2-weighted magnetic resonance imaging scans in sagittal plane. Results: Between subjects categorized into the type of tear, we found significant inter-categorical differences in isokinetic muscle strength during abduction, adduction, flexion, extension, and internal rotation, and in muscle endurance during flexion, extension, and internal rotation. Anteroposterior diameter tear, we did not show significant differences in either isokinetic muscle strength or muscle endurance during any movements. However, with modified mediolateral diameter, we found significant differences with isokinetic muscle strength during adduction, and in muscle endurance the external rotation and internal rotation. Conclusions: We found that a supraspinatus tendon tear associated with more numbers of rotator cuff tears has lower isokinetic muscle strength and muscle endurance than a tear found alone.

• Structural Engineering and Mechanics
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• 제52권2호
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• pp.427-443
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• 2014

This paper presents detailed analysis of the internal forces of interior beam-column joints of reinforced concrete (RC) frames under seismic action, identifies critical joint sections, proposes consistent definitions of average joint shear stress and average joint shear strain, derives formulas for calculating average joint shear and joint torque, and reports simplified analysis of the effects of joint shear and torque on the flexural strengths of critical joint sections. Numerical results of internal joint forces and flexural strengths of critical joint sections are presented for a pair of concentric and eccentric interior connections extracted from a seismically designed RC frame. The results indicate that effects of joint shear and torque may reduce the column-to-beam flexural strength ratios to below unity and lead to "joint-yielding mechanism" for seismically designed interior connections. The information presented in this paper aims to provide some new insight into the seismic behavior of interior beam-column joints and form a preliminary basis for analyzing the complicated interaction of internal joint forces.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.548-551
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• 2004

The main purpose of this study is to estimate the internal temperature of RC beam under fire. For this purpose, the finite difference method was used. In the previous studies, the structural behavior of fire damaged RC beams was investigated through experiments. The result was concluded that The high temperature affects the properties of concrete such as the elastic modulus, the compressive strength. The internal temperature Estimation of the concrete is helpful for understanding the structural behavior of fire damaged RC beams. Especially, high strength concrete has more spalling than normal strength one. So, this study is performed analysis of internal temperature of RC beam considering spalling.

• 대한통합의학회지
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• 제8권1호
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• pp.101-111
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• 2020

Purpose : The purpose of this study was to identify the comparison of the effects of manual therapy combined with exercise on range of motion (ROM), muscle strength, and functional performance in adolescent baseball players with internal impingement syndrome of the shoulder. Methods : The subjects were 30 patients diagnosed with impingement syndrome of the shoulder. Thirty subjects are randomly assigned to each 3 different groups; Group 1. (exercise group), Group 2. (exercise+mobilization; EMOB group), Group 3. (exercise+mobilization with movement; EMWM group). The interventions were performed three times a week for 4 weeks. The main outcome measures were goniometer, Biodex dynamometer, and Korean Kerlan Jobe shoulder-elbow (K-KJOC) scores. The ROM (external and internal rotation), muscle strength (external and internal rotation: 60 °/sec., 180 °/sec.), and functional performance were compared among the groups. Results : No significant difference was observed among the groups in the range of external rotation of the shoulder before and after the intervention, but the range of internal and total rotation was significantly increased in Group 2, 3 compared to Groups 1. Muscle strength of external and internal rotation (60 °/sec., 180 °/sec.) was not significantly different among Group 1, 2, 3, and functional performance was significantly increased in Group 2, 3 compared to Group 1. However, there was no significant difference between Group 2 and Group 3 in all measurements. Conclusion : An intervention with manual therapy such as EMOB and EMWM was more effective than exercise alone for rapid recovery from shoulder injury and improvement in functional performance. However, further efforts are needed to identify effects of specific interventions with manual therapy.