• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.220-220
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• 2000

In this paper, some non-interaction problems in tandem cold rolling mill are considered, which are required to control effectively a thickness of the cold .oiled strip. First, Interstand non-interactive compensate. (Interstand NIC) is designed for decoupling the interaction between stands. Next, a L2 optimization based pre-compensator is designed for decoupling the interaction between roll gap and strip tension in the stand. Finally, the effectness of the proposed decoupling methods is demonstrated via simulations.

• 한국산업융합학회 논문집
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• 제4권4호
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• pp.379-386
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• 2001

The lower toughness or brittle materials for mechanical test lead to the additional requirement that applied displacements be controlled with high resolution. Biaxial tension and shear tester using stepper motor with harmonic driver is shown. The device had to be high resolution so that the crack initiation process of slow extension and steady growth could be examined, Grip plates were connected to a linear bearing and actuator. The actuators consisted of stepper motors with harmonic driver connected to pre-loaded ball screw and nut assemblies. The encoders and motor controllers were connected to a personal computer so that arbitrary displacements histories could he prescribed in normal and tangential directions. The linear bearings were used to react loads perpendicular to their axes while allowing low friction, parallel movement of the attached grips. Load cells measured the reactions normal and tangential. the loads measured the reactions were recorded by the computer.

• 소성∙가공
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• 제26권1호
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• pp.41-47
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• 2017

Cyclic behavior of advanced high strength steel sheets was measured using an inverse-optimization approach with pre-straining and bending. First, tensile specimens were pre-strained, and three-point bending was conducted for the pre-strained specimens. By using the inverse finite element optimization, the combined isotropic-kinematic hardening parameters that minimize the error between the measured and predicted bending force-displacement curves. The measured cyclic behavior agreed well with the cyclic behavior measured by sheet tension-compression test, which confirms the validity of the measuring procedure based on inverse optimization.

• KCI Concrete Journal
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• 제12권1호
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• pp.69-77
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• 2000

The reinforced concrete(RC) flexural members strengthened with steel plate/CFS at soffit have initial stresses and strains in reinforcements and concrete caused by the service loads at the time of retrofitting works. These initial residual stresses and strains of strengthened beams may affect the flexural performance of the rehabilitated beams. The objective of this study is to evaluate and verify the effectiveness of rehabilitation by external bonded steel plates and CFS to the tension face of the beams under three conditions of pre-loading. Thirteen beam specimens are tested and analyzed. Main test parameters are pre-loading conditions, strengthening materials and reinforcement ratio of specimens. The effect of test parameters on the strengthened beams is analyzed from the maximum load capacity, load-deflection relationship, state of stress of the materials. crack propagation phase, and failure modes. Both test results and design formulas of ACI Code provisions are compared and evaluated.

• 한국간호교육학회지
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• 제14권2호
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• pp.273-281
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• 2008

Purpose: This study was performed to investigate the effects of aromatherapy on headache, stress and immune response of students with tension-type headache. Method: This study employed a two-group pre-post test study design. Data was collected from 44 subjects. Twenty-two subjects were assigned to the experimental group and received aromatherapy massage every other day for 3 weeks, but the other 22 subjects were in the control group and did not receive any intervention. Experiment had been conducted from Apr. 9 through Aug. 25, 2001 and intensity of headache, stress response (serum cortisol, life stress) and immune response(T-cell and natural killer cell ratio) were measured in the course of aromatherapy for both experimental group and control group. Data were analyzed by using $X^2$-test, t-test, Paired t-test and repeated measures ANOVA. Result: Headache scores, serum cortisol levels and life stress scores were significantly decreased in the experimental group after treatment compared to the control group. Conclusion: These findings is suggested that the aromatherapy could be an effective nursing intervention in relaxing and relieving the pain caused by tension-type headache for students.

• Steel and Composite Structures
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• 제26권5호
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• pp.573-582
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• 2018

This study develops and numerically verifies an innovative seismically resilient bracing system. The proposed self-centering tension-only brace (SC-TOB) is composed of a tensioning system to provide a self-centering response, a frictional device for energy dissipation, and a high-strength steel cable as a bracing element. It is considered to be an improvement over the traditional self-centering braces in terms of lightness, high bearing capacity, load relief, and double-elongation capacity. In this paper, the mechanics of the system are first described. Governing equations deduced from the developed analytical model to predict the behavior of the system are then provided. The results from a finite element validation confirm that the SC-TOB performs as analytically predicted. Key parameters including the activation displacement and load, the self-centering parameter, and equivalent viscous damping are investigated, and their influences on the system behavior are discussed. Finally, a design procedure considering controlled softening behavior is developed and illustrated through a design example.

• Physical Therapy Rehabilitation Science
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• 제8권4호
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• pp.202-209
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• 2019

Objective: The purpose of this study was to evaluate the effects of temporomandibular joint and cervical vertebra treatment in persons with tension-type headaches on pain, tenderness, and functional improvement. Design: Three-group pretest-posttest design. Methods: Subjects with tension-type headaches were divided into the temporomandibular joint and cervical vertebra treatment group (n=11), temporomandibular joint treatment group (n=11), and cervical vertebra treatment group (n=11), and pre- and post-evaluation was performed. The temporomandibular joint treatment group underwent compression massage and joint ply of the muscles around the temporomandibular joint. The cervical vertebra group received deep tendon massage and Myofascial Release of the cervical muscles. The temporomandibular joint and cervical vertebra treatment group performed both types of treatment. Treatment was performed for 50 minutes, three times a week for 4 weeks. Measurement tools included the Korean version of the short form-McGill Pain Questionnaire (SF-MPQ, K), Headache Impact test-6 (HIT-6), Neck Disability Index (NDI), and the Digital Algometer FPX25. Results: The groups showed significant differences in SF-MPQ, HIT-6 test, NDI, and Alogometer FPX25 test scores before and after intervention (p<0.05). The differences between the groups were most significant in the group that received treatment of the temporomandibular joint and cervical vertebra (p<0.05). Conclusions: In this study, the treatment of the temporomandibular joint and cervical vertebra was shown to be effective for improving pain, quality of life, and cervical vertebra in persons with tension-type headaches. This data may be helpful in identifying treatment techniques for tension-type headaches in the future.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.895-898
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• 2008

본 연구는 최근 국내의 옹벽 및 교대의 신기술 특허 등록 동향을 조사하여 파악하며, 이들 신기술특허를 적절히 실제 옹벽 및 교대 공사에 적용하려는데 목적을 두고 있다. 본 연구에서 조사된 신기술옹벽으로는 PS강봉에 프리스트레스를 도입한 단면력 저감형 조립식 PC옹벽공법, Coupler-Tension 조립식 옹벽, 도로용 블록식 보강토옹벽, 균등침하를 유도할 수 있는 블록식 보강토옹벽이 있으며, 신기술 교대로는 시트파일을 이용한 교대의 시공공법, 일체식 복합교대 교량, 반 일체식 교대교량의 시공방법, 보강토 교대구조를 기술하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.137-142
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• 2003

In this study, the propagation behavior of fatigue crack effected hole defects was investigated under mixed-mode I+II loading. To create mixed-mode stress field at crack tip, the compact tension shear (CTS) specimen and loading device were used in this tests. The propagation experiments of fatigue crack were performed by changing of the loading application angle(${\phi}$) and the distance(L) estimated from pre-crack tip to hole center located side by side by side with a pre-crack. As L changes, the variation for propagation aspect of fatigue crack, fatigue life and crack propagation rate were examined under mixed-mode loading. Under mixed-mode loading, the propagation rate of fatigue crack increased while the propagation direction changed dramatically because of the interference of hole defects.

• 한국구조물진단유지관리공학회 논문집
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• 제11권5호
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• pp.123-134
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• 2007

본 논문은 기존 강합성 교량의 내하력 향상을 목적으로 외부 긴장재의 초기 긴장력 결정 방법을 제시하였다, 외부 긴장력은 콘크리트 슬래브 재시공 전과 후에 각각 적용하였다. 활하중에 의하여 발생하는 증가 프리스트레스력을 고려한 내하율식을 제안하여 긴장재 개수와 초기 긴장력의 결정 과정을 제시하였다. 기존 강합성 교량의 내하율 향상에 적용하여 그 타당성을 입증하였다.