• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.3
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• pp.21-29
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• 2023

In this study, the stress characteristics of temporary fixed steel rods were analyzed in the "temporary fixing system using internal prestressing tension", which is mainly applied to the construction of superstructures by FCM. It was difficult to confirm the changes in initial tensile force in this system because the steel rod was internally connected to the pier and the PSC BOX. Therefore, measurement was performed before and after the completion of each segment using an FBG sensor to measure the change in the micro length of the steel rod. The results of the analysis showed that 75% to 90% of the maximum vertical contraction of the steel rod that occurred until the completion of the cantilever segment occurred in the fixing ~ 1segment, and the maximum loss of initial prestressing force was 39%. Such excessive loss of tension force to 1 segment means that tension is needed to improve the precision of construction during the fixation, and re-tension is needed to secure stability for conduction of cantilever segments after the completion of 1segment. In the 2 ~ last segment, the stress of the steel rod decreased gradually, and in the summer, the decrease in stress tended to partially recover due to the increase in the length of the steel rod corresponding to the increase in the vertical volume of PSC BOX. The dominant factor in the stress change in 2~ last segment in this phenomenon is judged to be the change in the length of the steel rod according to the temperature. Unlike the change in length, the relaxation was 1.2-2.7%, which was mostly offset by the opposite stress corresponding to the temperature stress. Therefore, a plan was proposed to improve the internal stress, such as adjusting the fixation time.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.711-718
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• 2013

This study examined the effect of 3 evaluation factors(extraction temperature, extraction time and drinking temperature) on the 5 tastes (sour, sweet, malty, salty and bitter) of coffee. the aim of this experiment were threefold: i) to investigate the change of the 5 tastes depending on the each 3 evaluation factor ii) to examine the change of the 5 tastes depending on the extraction time, drinking temperature under fixing the group of extraction temperature iii) to research the preference for the taste of coffee depending on 3 evaluation factors. As a result, in relation to the evaluation factors, significance difference was made at the sour taste. And when extraction temperature was higher and extraction time was longer, the sour taste was felt stronger. To the contrary, when drinking temperature was lower, sour was stronger. When the extraction Temperature group was controlled, the sour and malty taste were stronger. The sour taste was stronger when drinking temperature was lower and delicate flavor was stronger when drinking temperature was higher. High preference was demonstrated at extraction temperature($98^{\circ}C$), extraction time(0 minute), drinking temperature($60^{\circ}C$) and higher malty taste.

• The Journal of Engineering Geology
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• v.18 no.2
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• pp.227-232
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• 2008

In this study, the pull out resistance characteristics of an anchor bar to support a spillway installed in a slope are investigated by field tests. The injection materials were a cement mortar and cement milk. Unconfined compression strengths of those materials under several conditions were measured. As the result of compression test, the unconfined compression strengths of the cement mortar and the cement milk have positive proportional relation-ship with the water-cement ratio. They also have negative proportional relationship with increasing the curing time. In the same condition of water-cement ratio and curing time, the unconfined compression strength of cement milk is larger than that of cement mortar. In order to reduce the eccentricity in anchor bar during pull-out test in the field, the installation apparatus was improved by inserting a nut type of steel fixing coupling into the anchor bar. As the result of the pull-out test, the strength modification of cement milk was increased steeply at the early curing time. However, that of cement mortar was increased gradually with passing the curing time. Therefore, the cement milk has to use as the injection material for a prompt construction of anchor bar because the strength modification of cement milk is occurred at the early curing time.

• Physical Therapy Korea
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• v.16 no.4
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• pp.8-15
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• 2009

Grip strength is an objective indicator for evaluating the functional movement of upper extremities. Therapists have been using it for a long time as an excellent barometer for evaluating the therapy process, therapeutic effects and prognosis of patients with injuries in upper extremities. This study investigated the effects of extensor pattern position and elastic taping of non-dominant hand on the grip strength of dominant hand among general adults. The subjects of this study were 23 males and 7 females from physical therapy departments of 3 Universities located in Busan who agreed to participate in the experiment and the resultant data were analyzed using SPSS version 12.0. The results of the study were as follows. First, there was a significant difference between the grip strength of dominant hand when the non-dominant hand was at the neutral position and that when the non-dominant hand was at the extensor pattern position and both hands were at the maximum strength simultaneously (Bonferroni-corrected p<.001). Second, there was a significant difference between the grip strength of dominant hand when the non-dominant hand was at the neutral position and that when the elastic taping of non-dominant hand was applied (Bonferroni-corrected p<.001). Third, there was no significant difference between the grip strength of dominant hand when the non-dominant hand was at the extensor pattern position and both hands were at the maximum strength simultaneously and that when the elastic taping of non-dominant hand was applied. The irradiation effects through the extensor pattern position of non-dominant hand and application of the elastic taping to non-dominant hand showed significant results in improving the maximum grip strength of dominant hand. This finding could be suggested as the probability for the indirect treatment of the upper extremities of hemiplegia and orthopedic patients due to the long-term fixing of upper extremities.

• Korean Journal of Applied Biomechanics
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• v.24 no.1
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• pp.51-57
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• 2014

The purpose of this study was to compare and analyze kinetic variables of lower limbs according to types of ankle taping in drop landing. For this, targeting seven male basketball players (average age: $20.8{\pm}0.74yrs$, average height: $187.4{\pm}3.92cm$, average weight: $79.8{\pm}7.62kg$) with no instability of ankle joints, the drop landing motion was conducted according to three types of inelastic taping (C-type), elastic taping (K-type), and no treatment (N-taping). Based on the result, the next conclusion was reached. First, the effect of taping for the players with stable ankles was minimal and the high load on ankle joints offset the fixing effect of inelastic taping. Thus the inelastic taping for the players with stable ankles did not have an effect on the control of dorsal flexion during one-foot landing. Second, increasing angular velocity by increasing the movable range of knee joints disperses impact forces, yet inelastic taping restricted the range of knee joint motion and at the same time increased angular velocity, adding to a negative effect on knee joints. Third, inelastic taping induced inefficient motion of Lower limbs and unstable impact force control of ankle joints at the moment of landing and produced maximum vertical ground reaction force, which led to an increase of load. Therefore, inelastic ankle taping of players whose jump actions occur very often should be reconsidered. Also, it is thought that this study has a great meaning in proving the problem of inelastic taping related to knee pain with unknown causes.

• Clean Technology
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• v.10 no.1
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• pp.19-25
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• 2004

The leather was fixed with various colors through the dyeing process in leather manufacturing. During the dyeing process, the amount of 30~50% dyestuff which were not bonded with leather drained with waste water. These dyestuff raise lots of environmental problems, so technology for improving the fixing effect, levelling effect and penentration effect with the use of small amount of dyestuff has been required. Also, insufficient color fastness level 2~3 grade for common natural leather needs to be improved at the same time. Accordingly, the use of ultrasound(us) in dyeing process has decreased the amount of dyestuff and obtained the smooth permeability effect. So, we could find that the reduction of amount of dyestuff in wastewater led to decrease in environmental trouble caused by leather waste water with severe contamination degree and improved fastness up to 0.5 grades.

• Journal of the Korean Society of Costume
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• v.54 no.3
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• pp.145-158
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• 2004

In modern art, body appears as artistic performer, material or producer. and is expressed as' social environment body' which is changed in the relationship with its society and culture. The correlation between body and clothing image appears in 'body as expression object' which directly borrows human body or sets up a section of human body, 'body as medium' in which clothing substitutes body, and 'body as image' in which image of body reappears along with clothing. The results of analysis are as follows : First, 'image of expansion and exaggeration' to expand the influence of clothing thereby disclosing illusion of material civilization prevalent in our society, and make metaphor of dwarfish human's lurking fear by transforming and exaggerating human body. Second, 'image of restriction and suppression' to express the loss of humanity, power and restriction of modern society with fixing and cruelty of body image through clothing which disregard body function. Third, 'image of open and fluidity to criticize the extinction of values of human existence and standardized figure of our society by reducing three-dimensional clothing and body to untypical form or introducing the image of absent of human body to clothing. Fourth, 'image of reversion and paradox' to express practical clothing object with unwearable material, or cause confusion of sex and identity by expressing dual aspects of body at the same time. In this study, which is focused on correlation between body and clothing and the meaning of them, I realized that, even though artistic clothing expressed image of distortion and deformation of human existence as essential subject of body, they, in most contents, were used as medium of communication to rediscover human dignity and identity, and consisted of a series of metaphoric network of meanings satirizing aspects of our society.

• Journal of the Korean Vacuum Society
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• v.22 no.5
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• pp.262-269
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• 2013

Though focused ion beam (FIB) is one of the candidates to fabricate the nanoscale patterns, precision milling of nanoscale structures is not straightforward. Thus this poses challenges for novice FIB users. Optimal determination in FIB parameters is a crucial step to fabricate a desired nanoscale pattern. There are two main FIB parameters to consider, beam current (beam size) and dose (beam duration) for optimizing the milling condition. After fixing the dose, the proper beam current can be chosen considering both total milling time and resolution of the pattern. Then, using the chosen beam current, the metal nano hole structure can be perforated to the required depth by varying the dose. In this experiment, we found the adequate condition of $0.1nC/{\mu}m^2$ dose at 1 pA Ga ion beam current for 100 nm thickness perforation. With this condition, we perforated the periodic square array of elliptical nano holes.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.603-606
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• 2006

We present a study on the development of a practical and quantitative technique for the assessment of the structural health condition with using piezoceramic(PZT) sensors. The electro-impedance-based technique with the PZT patches is very sensitive for evaluation of the incipient and small damage in a high frequency range, and however the commonly traditional modal analysis method is effective only for considerably larger damages in low frequency range. The paper presents the technique in detecting and characterizing real-time damage on the specimen that is an aluminum plate fastened with bolts and nuts by different torques and as well a plate with a crack. By using the special arrangement of the PZT sensors, the required longitudinal wave is generated through the specimen. A large number of experiments are conducted and the different conditions of the specimens, i.e. the location and extent of loosening bolts, and the plate with a crack are simulated. respectively. Since fixing and loosening the loosened bolt is controlled by a torque wrench, we can control exactly the experiment of the different torques. Compared with the simulated healthy condition, we can find whether or not there is a damage in the specimen with using an impedance analyzer with the PZT sensors. Several indices are discussed and used for assessing the different simulated damages. As for the location of bolt loosening, the RMSD is found to be the most appropriate index for numerical assessment and as well the RMSD shows strongly linear relationship for assessing the extent of the bolt loosening, and the frequency peak shift ${\Delta}F$ is used to assess the cracked plate. The possibility of repeatability of the pristine condition signatures is also presented and the appropriate frequency range and interval are uniquely selected through large numbers of experiments.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.10
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• pp.40-45
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• 2007

Lightning warning system plays an important role in protecting human life and other facilities from lightning return strokes. This paper dealt with lightning positioning algorithms and circuits as a main function of lightning warning system, which monitor movements and activities of thunderclouds. Electric field component produced by lightning discharge is detected by the configuration of a whip antenna and a narrow-band resonance amplifier with center frequency of 300[kHz]. Measurement circuit of magnetic field waveform consists of a crossed-loop coil and an integral amplifier, and its frequency bandwidth is ranges from 5[kHz] to 1.2[MHz]. The polarity of lightning discharge is discriminated by electric field component. After-fixing the polarity, we can calculate the direction and distance of lightning discharge by the peak and the zero-cross time of magnetic field waveform.