• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3C
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• pp.187-196
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• 2008

An earthquake of magnitude 5.0 occurred at Ssang-gye-sa, a Buddhist temple in Jirisan, located near the southern border of the Korean peninsula on 4 July 1936. It resulted in severe damage of several buildings and structures in Ssang-gye-sa. Particularly, the top component of a five-story stone pagoda in the temple was tipped over and fell down during the earthquake. This earthquake damage case would be usefully applied to estimating the intensity of ground motion in the Korean peninsula, a moderate seismicity region, where strong motion has never been recorded with the exception of historic seismic events. In order to estimate the local site effects and the corresponding ground motion at Ssang-gye-sa site, intensive site investigations including borehole drilling and in-situ seismic tests such as crosshole and SASW tests were performed in the temple area. Based on the site characteristics, site-specific seismic response analyses using various input motions were conducted for a representative Ssang-gye-sa site by means of both one-dimensional equivalent-linear and nonlinear methods with six input rock outcrop acceleration levels ranging from 0.044g to 0.220g. The resultant site-specific seismic responses indicated the amplified ground motions in the short-period range near the site period of Ssang-gye-sa. Furthermore, the intensity on rock outcrop of the 1936 Jirisan earthquake was estimated by making a comparison between the site responses analysis results in this study and the full-scaled seismic test of pagoda model in the prior study.

• Journal of the Korean Geotechnical Society
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• v.34 no.8
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• pp.37-49
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• 2018

Since the observation of ground motions in South Korea, liquefaction manifestation was the first to be observed in Pohang earthquake in 2017 with $M_L$ 5.4. Because liquefaction causes ground settlement and lateral spread damaging in-ground or super structures, various researchers have been analyzing the Pohang liquefaction case history to better understand and predict liquefaction consequence and to prevent future disasters. In prior research at the 2018 EESK conference, a map of Liquefaction Potential Index (LPI), indicating the severity of liquefaction, in Pohang was created and compared with damage observations. The LPI correlated well with the observations, but the severity categorized by LPI range was significantly higher than the actual observations in most regions. The prior LPI map was created evaluating ground motions using the simplified approach. In this research, we perform the effective site response analyses with porewater pressure generation model for the detailed evaluation of liquefaction on the liquefied sites in Pohang. We found that the simplified approach for LPI evaluation can overestimate the severity.

• Journal of Music and Human Behavior
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• v.11 no.1
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• pp.1-19
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• 2014

The purpose of this study was to investigate the immediate effect of Patterned Sensory Enhancement (PSE) technique on the motor function of the affected upper limb in hemiplegic stroke patients by comparing the use of PSE and simple rhythmic cue. A total of 16 stroke patients were recruited from rehabilitative hospitals. The participants were assigned to the experimental group (n = 8) and control group (n = 8). While performing six different upper limb motions, musical stimuli applying the PSE technique was presented for the experimental group and simple rhythmic cue using the metronome was applied for the control group. The results showed that while the significantly increased range of motion (ROM) was found in the experimental group with the immediate use of PSE (p < .05), the control group did not show no significant change. This study implies that the use of musical elements in cueing for upper limb motion immediately leads to significant improvement in ROM by providing sufficient temporal, spatial, and dynamic information for expected motor performance.

• (The) Research of the performance art and culture
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• no.38
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• pp.349-383
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• 2019

This discussion is focused on Donghaeanbyulsingut's 'gutchum-pan to pray'. 'Gutchum-pan to pray' is repeated in almost all of the geori in Byulsingut, so it is a crucial chum-pan that can never be disregarded in understanding Byulsingutchum. Meanwhile, it supposes that Donghaeanbyulsingut is grounded on the activity of producing 'praying (words) and dance (motions)' within its relationship with the structure of capitalistic society along with the context of traditional rituals. The motion that is newly generated as a response to the concrete expression of 'praying' conducted by a mudang (a shaman), that is, the expression coming from the inside associated with the praying is seen as gutchum. This dance is bound to be in competition and interest among shaman groups, and they tend to influence one another. If praying leads to dance, a mudang can gain profits from capital as well as the value of labor. When the mudang succeeds in forming a bigger bond of sympathy with her praying, the object of praying gets more eager to select byulbi and dances a heoteunchum (impromptu dance) more vigorously. This means that a mudang's ability to perform a ritual is associated with the object of praying's consumption. With his impromptu motions, the object of praying comes to go into 'the field of consumption' within the structure of capitalistic competition before he is aware of it. Behind the communication that praying leads to dance, a lot of things are associated with one another organically. 'Gutchum-pan to pray' is generated by the continuous movement of diversity and unity that the time has within the ritual of the mudang and the object of praying. It continues to create the future 'self' that is different from the present 'self', and it means that he expects variability from the present 'self' through 'gutchum-pan to pray'. The mudang also prays for him arranging the variability of the other (the object of praying) inside her labor. In a big picture, of course, the mudang expects the variability of herself, too, which is connected to the value of her labor. The variability that they expect forms a crucial axis that determines where the flow of time and space that the 'gutchum-pan to pray' has is directed to. The contents of praying are directly related with the villagers' lives, and what leads to dance is mostly related with their jobs. This implies that what the mudang experiences in her everyday consuming activity is directly associated with the villagers' activity for earning money. In other words, the contents of that praying change constantly according to the flow of capitalistic economy. Also, those striving to respond to it before anyone else also expect better life for them by substituting their self to the 'gutchum-pan to pray' eagerly. If so, who are the ones that generate 'gutchum-pan to pray'? This can be understood through relationship among mudangs, relationship between the mudang and villagers, and also relationship among villagers. Their relationships can never be free from the concepts like labor in capitalistic society, consumption and expenditure, or time; therefore, they come to compete with the other, the present self, or the better self within the diverse relationships. This gets to be expressed in any ways, words or motions. And the range that covers the creation of either group or individual 'gutchum-pan to pray' in the village is the village community. Outside the range, it is upsized to the competition of the village unit, so individual praying may become diminished more easily. Although mudangs pray in each geori, it does not mean all praying leads to dance. Within various relationships between mudangs and villagers, 'gutchum-pan to pray' comes to be generated, repeated, and extinct. As it is mitigated to more positive competition, it does not lead to gutchum any longer. In other words, repeating 'gutchum-pan to pray' previously created has turned the object of praying into the state different from the former. Also, the two groups both have experienced the last step of Byulsingut, and at that point, praying does no longer lead to dance. In other words, from the position of the shaman group, it is the finish of their labor time and ritual performance, and from the perspective of the villagers, it means the finish of consuming activity and participation in a ritual. The characteristics of 'gutchum-pan to pray' can be summarized as follows. First, it goes through the following process: competition in the village group → competition in the group → competition among individuals. Second, repeated praying does not lead to 'gutchum'. Third, in the cases of praying for each of the occupation groups, the mudang can induce a bond of sympathy from the objects of praying directly, and this lead to dance. Fourth, the group that fails in being included in the category of praying gets to be alienated from 'gutchum-pan to pray' repeatedly.

• International Journal of Fluid Machinery and Systems
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• v.10 no.2
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• pp.119-137
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• 2017

Although the stall stagnation phenomena have often been experienced in site and also analytically in numerical experiments in surges in systems of compressors and flow paths, the fundamental causes have not been identified yet. In order to clarify the situations, behaviours of infinitesimal disturbance waves superposed on a main flow were studied in a simplified one-dimensional flow model. A ratio of the amplifying rate of the system instability to the characteristic slope of the compressor element was surveyed as the instability enhancement factor. Numerical calculations have shown the following tendency of the factor. In the situation where both the sectional area ratio and the length ratio of the delivery flow-path to the suction duct are sufficiently large, the enhancement factors are greater in magnitude, which means occurrence of ordinary deep surges. However, in the situation where the area ratio and/or the length ratio is relatively smaller, the enhancement factor tends to lessen significantly, which situation tends to suppress deep surges for the same value of the characteristic slope. It could result in the stall stagnation condition. In the domain of area ratio vs. length ratio of the delivery duct to the suction duct, contour-lines of the enhancement factor behave qualitatively similar to those of the stall stagnation boundaries of a fan analytically obtained, suggesting that a certain range of the enhancement factor values could specify the stagnation occurrence. The significant decreases in the factors are observed to accompany appearances of phase lags and travelling waves in the wave motions, which macroscopically suggests breaking down of the complete surge actions of filling and emptying of the air in the delivery duct. The strength of the action is deeply related with acoustic interferences and is evaluated in terms of the volume-modified reduced resonance frequency proposed by the author. These observations have shown the fundamental cause and the sequence of the stall stagnation in principle.

• Physical Therapy Korea
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• v.6 no.3
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• pp.11-21
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• 1999

Human balance is maintained through a complex process involving sensory detection of body motions, integration of sensorimotor information within the central nervous system, and execution of appropriate musculoskeletal responses. The basic task of balance is to position the body center of gravity (COG) over some portion of the support base. When the COG extends beyond the base of support, the person has exceeded the limits of stability (LOS). At this point, a step or stumble is required to prevent a fall. Automatic postural responses operate to keep the COG over the base of support. They are a set of functionally organized, long-loop responses that act to keep the body in a state of equilibrium. There are four commonly identified automatic postural responses, or strategies. These are ankle strategy, hip strategy, suspensory (knee) strategy, and stepping strategy. Thus, the purpose of this study was to evaluate the LOS using various knee strategies. Forty subjects participated in this study. The subjects were comprised of 20 males and 20 females who were without neurologic, orthopaedic or balance performance impairments. The LOS was measured with a Balance Performance Monitor (BPM) Dataprint Software Version 5.3. The results of this study were as follows: 1) Knee joint angle which is to increase stability of standing balance with using knee strategy was at mid-range. 2) There were statistically significant differences in anteroposterior LOSs according to the knee strategy. 3) There were no statistically significant differences in mediolateral LOSs according to the knee strategy. 4) There were statistically significant differences of anteroposterior LOSs with using knee strategy according to gender. 5) There were no statistically significant differences in mediolateral LOSs with using knee strategy according to gender.

• Earthquakes and Structures
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• v.22 no.2
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• pp.169-184
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• 2022

The importance of seismicity in developing countries and the strengthening of buildings is a topic of major importance. Therefore, the study of several solutions with the development of new technologies is of great importance to investigate the damage on retrofitted structures by using probabilistic methods. The Federal Emergency Management Agency considers three types of performance levels by considering different scenarios, intensity and duration. The selection and scaling of ground motions mainly depends on the aim of the study. Intensity-based assessments are the most common and compute the response of buildings for a specified seismic intensity. Assessments based on scenarios estimate the response of buildings to different earthquake scenarios. A risk-based assessment is considered as one of the most effective. This research represents a practical method for developing countries where exists many active faults, tall buildings and lack of good implementable approaches. Therefore, to achieve the main goal, two high-rise steel buildings have been modeled and assessed. The contribution of buckling-restrained braces in the elastic design of both buildings is firstly verified. In the nonlinear static range, both buildings presented repairable damage at the central top part and some life safety hinges at the bottom. The nonlinear incremental dynamic analysis was applied by 15 representative/scaled accelerograms to obtain levels of performance and fragility curves. The results shown that by using probabilistic methods, it is possible to estimate the probability of collapse of retrofitted buildings by buckling-restrained braces and tuned mass dampers, which are practical retrofitting options to protect existing structures against earthquakes.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.65-71
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• 2007

The purpose of this study was to investigate variability of kinematic factors affecting the record in women's javelin throwing. For this study, 8 female-javelin thrower participated in this experiment. The three digital video cameras (Sony, 120x) were used to record motions. Kwon3D 2.1 was used to process data and they were analyzed with Excell for factors. The sampling rate of a camera was 60Hz and shutter speed of a camera was 1/1000sec. The coordinate data were filtered using a fourth-order Butterworth low pass filtering with an estimated optimum cut-off frequency of 6Hz. The results were as follows: 1. From cross step to landing of delivery, the average velocities of CoM of non-dominant athletes were greater than dominant athletes and those of CoM of non-dominant athletes less than dominant athletes, but at release dominant athletes had a lower average velocity and a variability than non-dominant athletes. 2. From cross step to landing of delivery, the average throwing velocities and variabilities of a javelin of dominant athletes were greater than dominant athletes, but at release, dominant athletes had a higher velocity than dominant athletes and had a equal variability. 3. At every events, a forward or backward angles and variabilities of non-dominant athletes were greater than dominant athletes. 4. From cross step to landing of delivery, dominant athletes' elbow average angles were greater than non-dominant athletes and the variabilities of latter less than non-dominant athletes, but at release dominant athletes' variabilities were smaller than non-dominant athletes. 5. At landing of delivery, dominant athletes' knee average angles and variabilities of a supporting foot were a greater than non-dominant athletes, and at release, dominant athletes' knee average angles was a greater but variabilities less than non-dominant athletes. In conclusion, the dominant threw javelins fast while having stable postures and the range of elbow's angle large.

• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.58-64
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• 2016

Vibrational characteristics of curved pipe structures are investigated with respect to the change of inside flow velocities. Based upon the Hamilton's principle, the equations of motions are derived, and the finite element equation is constructed to solve the frequency equation for curved pipe structures. When the initial tension is neglected in cured pipes, the natural frequencies are reduced as flow velocity increases, and the rapid decreases of the natural frequencies take place. However, when the initial tension is taken into account, the natural frequencies are not changed with the change of the flow velocity. In free vibrational simulation of pipe systems, it is necessary to calculate the initial force due to the velocity and the pressure of the fluid flow from the equilibrium. The force should be included in the equation of motion of the systems to get more accurate natural frequencies. The mechanical properties like stiffness or the location of pipe support need to be changed to avoid resonance. The natural frequencies are to be isolated from the frequency range of dominant vibration modes. The angles of elbows do not affect the change of the fundamental natural frequency, but affect the change of the third or higher natural frequencies.

• Bulletin of the Korean Chemical Society
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• v.16 no.12
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• pp.1193-1203
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• 1995

In this work, we focused on the setup of the tools for the analysis of the final rotational state distribution of photofragments in vibrational predissociations of triatomic van der Waals molecules A-B2. We found that reflection principle used for the direct photodissociation processes can also be applied to find out the final rotational state distributions for indirect photodissociation processes. The quantity which represents the strength of rovibrational coupling between the quasi-bound state and the final state is reflected into the mirror of the classical angular momentum function, instead of the initial state before light absorption used in the reflection principle of direct processes. The sign change in the first derivative of the interaction potential with respect to the bond distance of B2 is found to be the source of the binodal structures in the final rotational distributions of photofragments in the model system studied in this work. In MQDT analysis, short range eigenchannel basis functions were found to be localized in angle, in the previous work [Lee, C.W. Bull. Korean Chem. Soc. 1995, 16, 957.] and may be called angle functions. Angle functions enjoy simple geometrical structures which have simple functional relations with the final state distributions of photofragments. Two processes take place along the angle functions which resemble the quasi-bound state and dominate over other processes. Two such angle functions are found to be not only localized angularly but also localized either one of ends of B2 in motions along the bond of B2. These dominating photodissociation processes, however, cancel each other. This cancellation causes photodissociation to depend sensitively on the interaction potential at other angles than the dominant one. Part of potential surface where much larger torque exists can now play an important role in photodissociation. MQDT also enables us to see which processes play important roles after cancellation. This is done by examining the amounts of time delayed by asymptotic eigenchannels.