• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.251-257
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• 2018

There are various quality deteriorations of concrete such as plastic, drying shrinkage due to abrupt moisture evaporation, slump loss and cold joint under hot weather condition. To protect from above deteriorations, several kinds of modified bubble sheets have been applied to secure heat insulation performance. But, there is not enough application cases of bubble sheets at job site under hot weather condition. The objective of the paper is to investigate the temperature profile and crack occurrence of the concrete covered with five different kinds of surface curing sheets, which is placed under hot weather condition. Single layer transparent bubble sheet, white colored bubble sheet, aluminum metalizing bubble sheet and PE film are adopted for surface curing sheets. Test results indicated that application of aluminum metalizing bubble sheet had most favorable effect on the reduction of on temperature rise and on the crack reduction of concrete. But due to larger reflection of light by aluminum, it brings about visual pollution to the workers. Hence, the application of white colored bubble sheet can be the most desirable alternative to protect the concrete from hot weather in the field.

• Physical Therapy Rehabilitation Science
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• v.3 no.1
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• pp.49-54
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• 2014

Objective: This study aimed to identify how various applications of weight bearing on the affected side of hemiplegia patients affect the ability of balance keeping of the affected leg and the gait parameters. Design: Cross-sectional study. Methods: Eighteen patients with hemiplegia participated in this study. There were twelve males and six females. This study investigated the effects of the single-leg stance exercise on dynamic balance, weight bearing, and gait ability compared with four conditions. Dynamic balance and weight bearing were measured using the step test (ST) of the affected side in stroke patients. In addition, gait parameters were measured using the optogait system for analysis of the spatial and temporal parameters of walking in stroke patients. Results: This study investigated the effect of the single leg stance exercise on the paralysis side. The ST showed significant findings for all conditions (p<0.05). Therefore, knee extension and flexion exercise on the affected side single-leg stance (condition 4) significantly improved dynamic balance and weight bearing on the affected side (p<0.05). In the condition of moving the knee joint in a single-leg stance was discovered that the stance phase time significantly increased more than in the condition of supporting the maximal voluntary weight on the affected side (p<0.05). Conclusions: Single-leg stance on the paralysis side with knee flexion and extension increased symmetry in weight bearing during stance phase time. This study suggests that single-leg stance exercises augments improved gait function through sufficient weight bearing in the stance phase of the affected side.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.49-58
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• 2019

A study on the analysis of underground ground condition using 3D-GPR exploration was carried out in this paper. The test bed was constructed similar to the field, and the detection analysis was carried out for each depth of cavity and underground burial. Through this, we were able to know the permittivity of the ground by inversion, and we could confirm the depth of detection for the joint by accurate calculation. We confirmed the signal waveforms in the cavity under the road through 3D-GPR exploration, analyzed more quantitatively in subjective and empirical analysis. The subsidence and depth of the subsurface settlement can be observed through 3D-GPR survey, and ground condition change after the ground reinforcement can be confirmed through the exploration section.

• Physical Therapy Korea
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• v.28 no.1
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• pp.59-64
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• 2021

Background: Hip flexor muscles are very important in the hip joint structure as a mover and stabilizer. In addition, isometric hip flexor strength in the supine position needs to be considered with isometric core strength (WICS) to measure a precise strength in a clinical way. Objects: We compared isometric hip flexor strength in the supine position in subjects with and without WICS (between factors) and conditions with and without an external support (within factors). Methods: A total of 34 subjects (16 with WICS, 18 without WICS) participated in this study. We used the double-bent leg-lowering test to divide the subjects in two groups according to the presence of WICS. Isometric hip flexor strength was evaluated in the supine position both with and without an external support condition. The two-way mixed analysis of variance was applied to identify significant differences between groups (with vs. without WICS: between factors) and conditions (with vs. without an external support: within factors). Statistical significance was set at α = 0.05. Results: In subjects with WICS, isometric hip flexor strength was greater with an external support than without it (p = 0.0064). In subjects without WICS, there were no significant differences in isometric hip flexor strength in the presence or absence of an external support (p = 0.075). The isometric hip flexor strength was significantly greater with an external support condition in particular in subjects with WICS. Conclusion: The findings of this study reported that an external support condition in individuals with WICS may contribute to the improvement of isometric hip flexion strength in the supine position. Therefore, isometric core strength should be evaluated to distinguish the weakness between core region and hip flexors.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.113-118
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• 2023

Maintenance of semiconductor equipment processes is crucial for the continuous growth of the semiconductor market. The process must always be upheld in optimal condition to ensure a smooth supply of numerous parts. Additionally, it is imperative to monitor the status of the robots that play a central role in the process. Just as many senses of organs judge a person's body condition, robots also have numerous sensors that play a role, and like human joints, they can detect the condition first in the joints, which are the driving parts of the robot. Therefore, a normal state test bed and an abnormal state test bed using an aging reducer were constructed by simulating the joint, which is the driving part of the robot. Various sensors such as vibration, torque, encoder, and temperature were attached to accurately diagnose the robot's failure, and the test bed was built with an integrated system to collect and control data simultaneously in real-time. After configuring the user screen and building a database based on the collected data, the characteristic values of normal and abnormal data were analyzed, and machine learning was performed using the KNN (K-Nearest Neighbors) machine learning algorithm. This approach yielded an impressive 94% accuracy in failure diagnosis, underscoring the reliability of both the test bed and the data it produced.

• International Journal of Automotive Technology
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• v.7 no.4
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• pp.423-439
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• 2006

This paper proposes a hybrid analytic method for the prediction of vibrational and acoustic responses of reverberant system in the medium-to-high frequency ranges by using the PFA(Power Flow Analysis) algorithm and SEA(Statistical Energy Analysis) coupling concepts. The main part of this method is the application of the coupling loss factor(CLF) of SEA to the boundary condition of PFA in reverberant system. The hybrid method developed shows much more promising results than the conventional SEA and equivalent results to the classical PFA for various damping loss factors in a wide range of frequencies. Additionally, this paper presents applied results of hybrid power flow finite element method(hybrid PFFEM) by formulating the new joint element matrix with CLF to analyze the vibrational responses of built-up structures. Finally, the analytic results of coupled plate structures and an automobile-shaped structure using hybrid PFFEM were predicted successively.

• Journal of Photoscience
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• v.9 no.2
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• pp.394-396
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• 2002

The emission of microwave sulfur lamp is mainly composed of visible light. This lamp producing little infrared radiation, has high light efficiency, long lifespan and less power consumption. In comparison with xenon lamp, growing under sulfur lamp apparently postponed jointing, increased the number of tillers, accelerated root growth of wheat. Relatively, xenon lamp evidently promoted heading and grain maturation. The development characteristics of wheat plant under sulfur lamp were more similar with that in natural condition.

• International Journal of Korean Welding Society
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• v.4 no.1
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• pp.46-52
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• 2004

To combine the mechanical advantages of ceramics with those of metals, one often uses both materials within one composite component. But, as known, they have different material properties and fracture behaviors. In this study, a four-point bending test is carried out on $Si_3N_4$ joined to ANSI 304L stainless steel with a Ti-Ag-Cu filler and a Cu interlayer at room temperature to evaluate their longitudinal strain behaviors. And, to detect localized strain, a couple of strain gages are pasted near the joint interfaces of the ceramic and metal sides. The normal strain rates are varied from $3.33{\times}10^5$ to $3.33{\times}10^{-1}s^{-1}$ Within this range, the experimental results showed that the four-point bending strength and the deflection of the interlayer increased with increasing the strain rate.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1934-1937
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• 1999

A copper-tungsten sintered alloy(Cu-W) has been friction-welded to a tough pitch copper (Cu) in order to investigate friction weldability. The tensile strength of the friction welded joint was increased up to 87% of the Cu base metal under the condition of friction time 1.0 see, friction pressure 40MPa and upset pressure 100MPa, upset time 5.0 sec. And it is related to upset pressure rather than friction time. Mixed layer was formed in the Cu adjacent weld interface and W particles which were included in mixed layer could induce fracture in the Cu adjacent to the weld interface. Thickness of mixed layer was reduced as upset pressure increase.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1254-1261
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• 2011

Application of long-span bridge, which is affected by parameters such as span length, shoe boundary condition, track property and stiffness of superstructure and substructure etc., can vary. Especially, by CWR aspects of the axial force, long-span high speed railway bridges are limited at type and span length. In this study, in terms of CWR axial force, the long-span high-speed railway bridges without REJ(Rail Expansion Joint) is to propose the bridge type. Various Parameters analysis performed for the proposed type(Arch bridge, Cable-stayed bridge).