• 화약ㆍ발파
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• 제35권4호
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• pp.1-9
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• 2017

본 연구는 인공절리를 이용한 발파효과 검토를 위해 인공절리 수, 인공절리 간격, 인공절리 경사에 따른 발파속도의 영향 및 기여도를 평가 분석한 연구이다. 인공절리 상태 변화에 따른 발파속도는 동적해석 프로그램인 AUTODYN을 이용하여 획득하였다. 수치해석 결과에 대해 정규화 분석을 수행하였고, 각 인자의 기여도 분석을 위해 강건설계 실험계획법을 이용하여 설계 인자를 분석하였다. 각 인자는 3수준으로 설정하였고, 분석에 직교 배열표 $L_9(3^4)$를 사용하였다. 정규화 분석을 통해 수치해석 결과를 분석한 결과 인공절리 경사가 증가함에 따라 발파속도는 감소하는 경향을 보였다. 또한, 인공절리 간격과 인공절리 경사에 대해 발파속도를 분석한 결과 발파속도는 경사가 수직일 때 인공절리 간격이 증가함에 따라 감소는 경향을 보였다. 강건설계를 이용한 기여율 분석결과 발파속도에 가장 큰 영향을 미치는 것은 인공절리 경사이며, 이어서 인공절리 수, 인공절리 간격 순으로 기여율이 평가되었다.

• 대한의용생체공학회:의공학회지
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• 제45권2호
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• pp.57-65
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• 2024

Recently, several studies have been conducted to lower the cost of transport of human by adding external joint stiffness elements. However, it has not been clearly elucidated whether adaptation time is required for human subjects to adapt to the added external joint stiffness. In this study, carbon plates in the form of shoe midsoles were added to the metatarsophalangeal joint, and the lower limb joint torque and mechanical energy consumption were compared before and after a total of 5 sessions (2.5 weeks) of running. A total of 11 young healthy participants exhibited higher elastic energy storage in carbon plates in the fifth session compared to the first session, and lower power in the ankle joint. This suggests that a single training session may be insufficient to validate the efficiency effect of added joint stiffness, and the human body seems to increase the elastic energy stored in the assistive joint stiffness and its reutilization.

• 소음진동
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• 제2권2호
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• pp.125-134
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• 1992

In this study, ti identify the dynamic characteristics of automobile steering system which consists of many components and joints, each component combined structure was analyzed using commercial structural package, ANSYS. And, the finite element method for each component and modeling method of several joints universal joint, bolt joint, bearing, etc. were studied. On the other hand, the experimental modal analysis was performed to compare with the results of the finite element analysis and joint modeling. The result shows very close agreement between two analysis. Also, it was found that the steeing column used in this experiment does not effect the low frequency mode of entire system. In addition, we found that constraint equations need to be considered in modeling universal joint. Since the stiffness effect of Urethane around wheel could be ignored, it can be modeled only with mass effect. In the end, it was found that dynamic characteristics of the entire steerintg system depends mainly upon the wheel characteristics.

• 턱관절균형의학회지
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• 제11권1호
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• pp.25-36
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• 2021

It was observed that the effectiveness of Yin-yang balancing therapy of the tempromandibular joint (YBT) or functional cerebrospinal therapy (FCS) in three cases: an acute and a chronic motor tic disorder and a Tourrette's disorder (TD). These three cases were mainly managed with cervical balancing appliance for the Yin-yang Balancing on tempromandibular joint (TMJ) and pelvic balance therapy. They were treated concurrently with acupuncture, cupping and herb-medicine. Clinical outcome measurement was based on subjective measures with visual analogue scale (VAS), Yale Global Tic Severity Scale (YGTTS) and clinical observations for 235, 279 and 273 days respectively. The patient showed positive changes after the treatment and this effect maintained over the follow-up period. Although it is not clear whether the effect is sustained afterwards or not, a positive effect on the motor tic disorders and TD was observed. And so, furthermore strict clinical and structural researches for verification on YBT is expected.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.469-474
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• 1999

The object of study is analysis to joint crack behavior of cracked joint concrete pavement. In the new constructing concrete pavement, joint crack behavior was compared general joint depth D/4 with joint depth D/3 and D/5 that it's environmental effects changed temperature and humidity. After joint saw cutting joint section was predicted crack at joint depth D/5 test section from the result for monitoring development of crack. In the setting of data logger system of the joint section, it's data compared see with the naked eye. In the research, development of crack at the joint section should effect to joint saw timing latter than joint depth. This performance could be the minimum of deterioration to the early curing. In this research, At new constructing of joint concrete pavement of highway, the monitoring system be setting after finished paving and joint sawing. The system and see with the naked eye could be analysis to pavement behaviors from collecting data at the test section. This system could be monitoring shot term and long term. In this report, joint section of crack behavior analysis used to collected data during a month after paving and joint sawing.

• 한국전자통신학회논문지
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• 제16권2호
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• pp.347-354
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• 2021

화학공장과 같은 장치산업은 고온·고압·유독성 유체가 배관을 통하여 각종 설비들 사이를 이동한다. 온도변화, 진동, 지진, 지반침하와 같은 주변환경의 변화에 의한 배관의 위치 이동과 파손은 인명피해를 수반하는 큰 사고로 연결되는 경우가 많다. 이러한 사고를 방지하기 위하여 배관에 가해지는 각종 충격을 흡수하고, 보완하여 사고를 미연에 방지하기 위한 여러 가지 종류의 익스펜션 조인트(Expansion Joint)를 사용한다. 따라서 사용된 익스펜션 조인트의 변형을 측정하고, 수명을 예측하는 것은 대형사고를 방지하기 위하여 매우 중요하다. 본 논문에서는 익스펜션 조인트의 변형을 일종의 모션으로 이해하고, Hall Effect Sensor와 9-Axis Sensor를 사용하여 변화를 측정하였다. 그리고 범용의 마이컴보드 아두이노와 C언어를 사용하여 측정된 데이터를 모으고, 분석하여 익스펜션 조인트의 변형을 예측할 수 있는 시스템에 대하여 연구하였다.

• Structural Engineering and Mechanics
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• 제83권5호
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• pp.693-707
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• 2022

Bonded joints have proven their performance against conventional joining processes such as welding, riveting and bolting. The single-lap joint is the most widely used to characterize adhesive joints in tensile-shear loadings. However, the high stress concentrations in the adhesive joint due to the non-linearity of the applied loads generate a bending moment in the joint, resulting in high stresses at the adhesive edges. Geometric optimization of the bonded joint to reduce this high stress concentration prompted various researchers to perform geometric modifications of the adhesive and adherends at their free edges. Modifying both edges of the adhesive (spew) and the adherends (bevel) has proven to be an effective solution to reduce stresses at both edges and improve stress transfer at the inner part of the adhesive layer. The majority of research aimed at improving the geometry of the plate and adhesive edges has not considered the effect of temperature and water absorption in evaluating the strength of the joint. The objective of this work is to analyze, by the finite element method, the stress distribution in an adhesive joint between two 2024-T3 aluminum plates. The effects of the adhesive fillet and adherend bevel on the bonded joint stresses were taken into account. On the other hand, degradation of the mechanical properties of the adhesive following its exposure to moisture and temperature was found. The results clearly showed that the modification of the edges of the adhesive and of the bonding agent have an important role in the durability of the bond. Although the modification of the adhesive and bonding edges significantly improves the joint strength, the simultaneous exposure of the joint to temperature and moisture generates high stress concentrations in the adhesive joint that, in most cases, can easily reach the failure point of the material even at low applied stresses.

• 한국자동차공학회논문집
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• 제6권1호
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• pp.143-150
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• 1998

The evaluation of joint fatigue strength of light weight materials for electrical vehicle body has been performed through single lap joint tests with the design parameters such as joint style, adherend, bonding overlap length and bonding thickness. Fatigue strength was evaluated through 5-Hz, tension-tension, load controlled test with the stress ratio zero value. It is experimentally observed that fatigue strength of joint increases for the increase of overlap length. The combinations of Al-Al and Al-FRP adherends show that fatigue strength of joint is hardly changed for the increase of bonding thickness, but FRP-FRP adherend specimen shows that fatigue strength of joint increases after decreases for the increase of bonding thickness. Al-Al adherend specimen has much higher fatigue length than Al-FRP and FRP-FRP adherend specimens. Riveting at adgesive bonded joint gives little effect on fatigue strength.

• 국제물리치료학회지
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• 제8권2호
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• pp.1152-1157
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• 2017

The aim of this study was to observe the effects of kinesiotaping and joint mobilization on the metatarsophalangeal joint angle and pain in hallux valgus patients Twenty-one female hallux valgus patients in their 20s were divided into two groups, a Kinesiotaping group (KT, n=10) and another group with the addition of joint mobilization (KTJM, n=11). After undergoing 6 weeks of intervention, the change in the metatarsophalangeal joint and pain were measured. Metatarsophalangeal joint angle was significantly increased both the KT and the KTMJ group after intervention. In the change of pain, both the KT and KTJM groups on an individual basis also experienced a significant decrease in pain, though comparison between the two groups failed to represent a significant difference. These findings suggest that Kinesiotatping and joint mobilization increased the joint angle and reduced pain.

• Journal of Acupuncture Research
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• 제30권2호
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• pp.9-15
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• 2013

Objectives : This study was done for reporting the effect of moxibustion therapy on Ryodoraku score of the patients with degenerative arthritis of knee joint. Methods : We investigated 65 cases of patients with degenerative arthritis of knee joint, and devided patients into two groups : One group treated by moxibustion therapy, which was not applied to the other group we analyzed of each group the Ryodoraku score(F1, F6) of each group before and after moxibustion therapy and compared it. Results : 1. In moxibustion therapy group compared with baseline, at final, Ryodoraku score(F1, F6) was significantly increased. 2. At final, moxibustion therapy group showed significant increase on Ryodoraku score(F1, F6) score compared with non moxibustion therapy group. Conclusions : It is suggested that Ryodoraku score(F1, F6) should be available for diagnosing degenerative arthritis of knee joint.