• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.1
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• pp.63-72
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• 2020

The purpose of this study is to investigate the effects of the application of various numerical models and frequency contents of earthquakes on the performances of the reactor containment building (RCB) in a nuclear power plant (NPP) equipped with an advanced power reactor 1400. Two kinds of numerical models are developed to perform time-history analyses: a lumped-mass stick model (LMSM) and a full three-dimensional finite element model (3D FEM). The LMSM is constructed in SAP2000 using conventional beam elements with concentrated masses, whereas the 3D FEM is built in ANSYS using solid elements. Two groups of ground motions considering low- and high-frequency contents are applied in time-history analyses. The low-frequency motions are created by matching their response spectra with the Nuclear Regulatory Commission 1.60 design spectrum, whereas the high-frequency motions are artificially generated with a high-frequency range from 10Hz to 100Hz. Seismic responses are measured in terms of floor response spectra (FRS) at the various elevations of the RCB. The numerical results show that the FRS of the structure under low-frequency motions for two numerical models are highly matched. However, under high-frequency motions, the FRS obtained by the LMSM at a high natural frequency range are significantly different from those of the 3D FEM, and the largest difference is found at the lower elevation of the RCB. By assuming that the 3D FEM approximates responses of the structure accurately, it can be concluded that the LMSM produces a moderate discrepancy at the high-frequency range of the FRS of the RCB.

• Korean Journal of Occupational Health Nursing
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• v.6 no.1
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• pp.23-43
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• 1997

The work-related diseases due to continuous overwork are mainly cerebro- and cardio-vascular ones, which is commonly called 'Karoshi', death from overwork. Many factors are capable for Karoshi : occupational stress in relation to technological renovation and industrial rationalization, competitive social structure, and accumulated fatigue accured to long time or irregular working. And its occurence is on the rise. The World Labor Report 1993 released by ILO, pointed out the diseases related to overwork and stress as one of the most important occupational health problem. In Korea, social awareness of Karoshi is at an infant stage, and reliable statistics for its occurence are not compiled in a convenient manner. Despite the rising Karoshi, there are no reliable clauses in workmen's compensation enough to settle down the disputes. Therefore, it is not uncommon that the Labour Ministry and Civil Court find difficulties in reaching an agreement. This study was intended to provide proper compensation and prevention program for workers by suggesting reasonable compensation clauses for the death from overwork. This study consists of two comparative reviews on the compensaton clauses for the death from overwork. One is to review legal standards of Karoshi among three countries, such as Korea, Japan and Taiwan. The other is to investigate the cases of Karoshi in Korea, 121 cases identified at the Labor Welfare Corperation and the Labour Ministrial process of examination and reexamination, and 73 leading cases at the High Court of Justice. The main findings of the study are as follows : 1. Comparisons of comperative review on compensation clauses for the death from overwork among three countries. 1) All of three countries have the same kinds of disease for compensation, which were cerebro-and cardiao-vascular diseases, while for cardiac disease group, Korea has the smaller number of diseases for compensation than Japan. 2) As for the definition of overwork, the three countries share equally that overload for one week prior to collapse is considered as an important factor, but accumulated chronic fatigue is disregarded. 3) As the basis of overwork, in Japan, there is a tendency to move from the conditions of an ordinary healthy adult to those of the individual concerned in Japan, whereas there is no such concern yet in Korea. 4) All the three countries use a common standard of medical judgement in demonstrating causal relationship between a job and a disease. However, Korea is progressive in the sense that in the case of CVA at worksite, the worker himself has no obligation to prove the cause. 2. The results of a comparative review on excutive decisions by Labor Ministry and judicial decisions by the Court in Korea : A judicial decision is based on the legalistic probability, but a excutive decision is not. Therefore, excutive decisions have such restrictions that : 1) TIA (transitory ischemic cerebral attack) and myocarditis are excluded from compensation, and there is little consistency of decision in the case of cause-unknown death. 2) There is a tendency not to compensate for the death from overwork since the work terms such as repeated long-time working, shift work or night-shift work are not considered as overloading. 3) There is a tendency to regard the conditions of a ordinary healthy adult rather than those of the individual concerned(age, existing diseases, health state, etc.) as the comparative basis of overload. 4) There remains a tendency not to compensate for the death from overwork in the case of collapse occuring out of workplace, on the ground of 'on the course of working' and 'in the cause of accident'. Through the study, the fact manifests itself that Korea's compensation clauses for work-related diseases due to overwork are very restrictive. So, it is necessary to extend the Labor Ministry's clauses of compensation for the death from overwork following to the recent changes of other countries and internal judicial decisions. This is very important in the perspective of occupational health that aims at health promotion of workers including prevention of the Karoshi.

• Korean Journal of Heritage: History & Science
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• v.53 no.3
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• pp.62-79
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• 2020

The rock-carved seated Avalokiteśvara statue at Ganghwa Bomunsa Temple is a giant rock-carved Buddhist statue that was built in 1928 during the Japanese colonial era. Although it is a year-recorded Buddhist statue that occupies a prominent place in modern Korean Buddhist sculpture history, it has not been the subject of in-depth discussion due to weak research on modern Buddhist sculptures. In this study, to examine the various significant aspects of the rock-carved Seated Avalokiteśvara statue at Bomunsa Temple as a modern Buddhist sculpture, I have managed to determine its construction year, artificers, and patrons by deciphering the inscription around the rock-carved statue; in addition I have researched the effects of the rock shapes and landforms on the formation of the Buddhist statue by comparing and analyzing the points of view of both artificers and worshipers. I have also identified the specific circumstances of the time of construction from interviews with the descendants of artificers. A monk from Geumgangsan Mountain, Lee Hwaeung, took the role of sponsor and chief painter to construct the rock-carved seated Avalokiteśvara statue at Bomunsa temple. In the beginning of its construction in 1928, more than 100 donators jointly sponsored the construction of the statue. Gansong Jeon Hyoungphil sponsored alone at the time of the place of worship's expansion in 1938. Bomunsa Temple has been regarded as one of the top-three sacred places of Avalokiteśvara Bodhisattva together with Naksansa Temple in Yang Yang and Boriam in Nam Hae, due to the construction of the rock-carved statue. It took about three months to construct the statue. Lee Hwaeung drew a rough sketch and then Un Songhag and five masons from Ganghwa Island took part in the carving process. We can observe the line drawing technique around the rock-carved statue because the statue was carved based on the rough sketch of the monk painter. The aspect of Lee Hwaeung as a painter is revealed; therefore, we can identify the clue of painting pattern leading to Seogongchulyou- Hwaunghyoungjin- Ilonghyegag. The rock-carved seated Avalokiteśvara statue at Bomunsa Temple is a typical Avalokiteśvara that wears a jeweled crown and holds Kundica. It makes a strong impression as it has a big square-shaped face and a short neck and is unsophisticated in general. The artificers solved the issue of visual distortion of the rock-carved statue caused by carving on a 10-meter high and 40-degree sloping rock by controlling motion to its maximum, omitting detailed expression by emphasizing symmetry, and adjusting the head-to-body proportion to be almost one-to-one. In this study, especially, I presume the unified form of sacred sculptures and Buddhist altars, without making a Buddhist altar like the rock-carved seated Avalokiteśvara statue at Bomunsa Temple, to be a key characteristic of modern Buddhist sculptures. Furthermore, I make newly clear that the six letters of Sanskrit carved on nimbus, which had been interpreted as a Six-Syllable Mantra, are a combination with Jeongbeopgye and Sabang Mantras. In addition, three iron rings driven on eaves rock were used as a reference point, and after construction they were used as a decoration for the Bodhisattva with hanging wind chimes.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.6
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• pp.1-8
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• 2005

In this paper, we propose a two-stage head tracking algorithm adequate for real-time active camera system having pan-tilt-zoom functions. In the color convergence stage, we first assume that the shape of a head is an ellipse and its model color histogram is acquired in advance. Then, the min-shift method is applied to roughly estimate a target position by examining the histogram similarity of the model and a candidate ellipse. To reflect the temporal change of object color and enhance the reliability of mean-shift based tracking, the target histogram obtained in the previous frame is considered to update the model histogram. In the updating process, to alleviate error-accumulation due to outliers in the target ellipse of the previous frame, the target histogram in the previous frame is obtained within an ellipse adaptively shrunken on the basis of the model histogram. In addition, to enhance tracking reliability further, we set the initial position closer to the true position by compensating the global motion, which is rapidly estimated on the basis of two 1-D projection datasets. In the subsequent stage, we refine the position and size of the ellipse obtained in the first stage by using shape information. Here, we define a robust shape-similarity function based on the gradient direction. Extensive experimental results proved that the proposed algorithm performs head hacking well, even when a person moves fast, the head size changes drastically, or the background has many clusters and distracting colors. Also, the propose algorithm can perform tracking with the processing speed of about 30 fps on a standard PC.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1186-1191
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• 2006

Removal efficiency of As(III) through oxidation and adsorption in column reactors was investigated at different ratios of manganese-coated sand(MCS) and iron-coated sand(ICS) : MCS-alone, ICS-alone and both of ICS and MCS. The breakthrough of arsenic immediately occurred from a column reactor with MCS-alone. However, most of the arsenic present in the effluent was identified as As(V) due to the oxidation of As(III) by MCS. While five-times delayed breakthrough of arsenic was observed from a column reactor with ICS-alone. At a complete breakthrough of arsenic, the removed As(III) was 36.1 mg with 1 kg ICS. To find an optimum ratio of ICS and MCS in the column packed with both ICS and MCS, the removal efficiency of As(III) was investigated at three different ratios of ICS/MCS with a fixed amount of ICS. The breakthrough time of arsenic was quite similar in the different ratios ICS/MCS. However, much slower breakthrough of arsenic was observed as the ratio of ICS/MCS decreased. As the ratio of ICS/MCS decreased the concentration of As(III) in the effluent decreased and then showed below 50 ppb at an equal amount of ICS and MCS, suggesting more efficient oxidation of As(III) by greater amount of MCS. When a complete breakthrough of arsenic occurred, the removed total arsenic with an equal amount of ICS and MCS was 68.5 mg with 1 kg of filter material.

• Restorative Dentistry and Endodontics
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• v.34 no.5
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• pp.424-429
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• 2009

This study aimed to assess the influence of different cross-sectional area on the cyclic fatigue fracture of Ni-Ti rotary files using a fatigue tester incorporating cyclical axial movement. Six brands of Ni-Ti rotary files (ISO 30 size with. 04 taper) of 10 each were tested: Alpha system (KOMET), HeroShaper (MicroMega), K3 (SybronEndo), Mtwo (VDW), NRT (Mani), and ProFile (Dentsply). A fatigue-tester (Denbotix) was designed to allow cyclic tension and compressive stress on the tip of the instrument. Each file was mounted on a torque controlled motor (Aseptico) using a 1:20 reduction contra-angle and was rotated at 300 rpm with a continuous, 6 mm axial oscillating motion inside an artificial steel canal. The canal had a $60^{\circ}$ angle and a 5 mm radius of curvature. Instrument fracture was visually detected and the time until fracture was recorded by a digital stop watch. The data were analyzed statistically. Fractographic analysis of all fractured surfaces was performed to determine the fracture modes using a scanning electron microscope. Cross-sectional area at 3 mm from the tip of 3 unused Ni-Ti instruments for each group was calculated using Image-Pro Plus (Imagej 1.34n, NIH). Results showed that NRT and ProFile had significantly longer time to fracture compared to the other groups (p < .05). The cross-sectional area was not significantly associated with fatigue resistance. Fractographycally, all fractured surfaces demonstrated a combination of ductile and brittle fracture. In conclusion, there was no significant relationship between fatigue resistance and the cross-sectional area of Ni-Ti instruments under experimental conditions.

• Journal of Animal Science and Technology
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• v.61 no.3
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• pp.147-153
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• 2019

A goal for swine farming is the improvement in the number of live-born and weaned piglets per sow. Hence, the effect of parities should consider the correlation between the component traits of reproductive performance, weaning, and duration. Sows were housed in farrowing pens (W 2.2 ${\times}$ D 1.8 ${\times}$ H 1.2 m) on a partially slatted plastic floor. Twenty sows used in this study were between the first and sixth parity in gilts (P1), parity 2-5 (P3), and parity 6-9 (P6). Data collection by parity was classified into three categories: (1) reproduction performance (gestation length, total number of piglets born, number of piglets live born, number of piglets stillborn, total piglet birth weight; (2) weaning traits (weaning period, number of piglets weaning, total piglets weaning weight); (3) duration traits (farrowing duration, placenta expulsion duration, time from last piglet to first placenta, average birth interval, and tail wagging behavior). Gestation length was higher in P6 than P1 and P3 of different parity sows. The maximum value in P1 and P3 was 117 days, but the median value in P6 was 117 days (p < 0.05). The total number of piglets born (p = 0.113), number of piglets live born (p = 0.118), number of still piglets born (p = 0.151), and total piglet birth weight (p = 0.117) were not affected by parity. The number of live piglets was higher than the other parities by an average of $15.6{\pm}2.1$ in P1. The duration of farrowing was the lowest at 22.2 min in P6, but the maximum value was 42.2 min more than other parities (p = 0.355). Weaning traits of sows also did not differ significantly (p > 0.05), but the weaning period from P1 was lower than that of the other parities (p = 0.170). The number of piglets weaned was 10 heads on average in P1, P3, and P6 (p < 0.05). However, the mean values of the total piglet weaning weight (p = 0.377) of P6 (62.0 10.4 kg) were higher than those of P1 (54.9 10.2 kg) and P3 (58.4 13.6 kg). The placenta expulsion duration was higher in P6 than that in P1 and P3 (p = 0.447). The time from the last piglet to first placenta was be lower in P3 than that of the other parities (p = 0.206). The average birth interval was higher in P3 than that of the other parities (p = 0.156). Tail wagging (count) behavior was higher in P6 than in the other parities (p = 0.065). The data showed that the reproduction performance, total piglets born, and weight were higher in the gilts group, and higher in the weaning trait than that in the P6 group. This study examined the relationship between reproductive performance, birth interval and tail motion according to sow parity. Regarding duration, farrowing duration was lower in P6 than that in the other parities, but placenta expulsion and tail wagging were higher in P6 than in the other parities. Therefore, it is possible that the results from these sows could be used as basic data for effective farm management.

• Journal of Korea Water Resources Association
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• v.52 no.10
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• pp.743-752
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• 2019

The flow in the meandering channel is characterized by the spiral motion of secondary currents that typically cause the erosion along the outer bank. Hydraulic structures, such as spur dike and groyne, are commonly installed on the channel bottom near the outer bank to mitigate the strength of secondary currents. This study is to investigate the effects of submerged vanes installed in a $90^{\circ}$ meandering channel on the development of secondary currents through three-dimensional numerical modeling using the hybrid RANS/LES method for turbulence and the volume of fluid method, based on OpenFOAM open source toolbox, for capturing the free surface at the Froude number of 0.43. We employ the second-order-accurate finite volume methods in the space and time for the numerical modeling and compare numerical results with experimental measurements for evaluating the numerical predictions. Numerical results show that the present simulations well reproduce the experimental measurements, in terms of the time-averaged streamwise velocity and secondary velocity vector fields in the bend with submerged vanes. The computed flow fields reveal that the streamwise velocity near the bed along the outer bank at the end section of bend dramatically decrease by one third of mean velocity after the installation of vanes, which support that submerged vanes mitigate the strength of primary secondary flow and are helpful for the channel stability along the outer bank. The flow between the top of vanes and the free surface accelerates and the maximum velocity of free surface flow near the flow impingement along the outer bank increases about 20% due to the installation of submerged vanes. Numerical solutions show the formations of the horseshoe vortices at the front of vanes and the lee wakes behind the vanes, which are responsible for strong local scour around vanes. Additional study on the shapes and arrangement of vanes is required for mitigate the local scour.

• (The) Research of the performance art and culture
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• no.34
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• pp.111-131
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• 2017

Korean Shamanism has long been regarded as the peripheral cult or supersition by the majoriy of the society. This fact is a result by the influence of the mass media, especially the motion pictures, which intentionally reflected the negative images of the Shamanism. The documentary films, which stress the objectivity and the reality, rather disclose the neutral position toward the Shamanism. In fact, the directors of the documentary films who have more or less close relationship with the Shamanism have tried to exhibit the mental world and the traditionality of the Shamanism. In this paper, I will explore the value of Shamanism reflected in the documentary films. I focus of two films; directed by the Korean and directed by a foreigner. In this way, I can compare the attitudes of the two directors toward the Korean Shamanism. The director of confessed that he was attracted by the aspect of a musical underlied in the shaman ritual. However, the film does not show the artistic beauty of the shaman music because the director failed to understand the essential aspect of the shaman ritual, that is, the music. In this way, the director failed to show the distinct characteristics of the shamanism to the audience. The director of , a music herself, was focused on the music of the shamanism. The story flows to the adventure to seek a "master" with a long journey to enjoy diverse genres of Korean performing arts. This story resembles the epic shaman song, the Princess Bari. In this way, the audience can easily grasp the beauty of Korean culture. Music is said to be a universal language and, at the same time, a non-universal language which reflects a special trait of a cultural community. The Korean shaman ritual music is a non-universal language that is an accumulation of the Korean culture for a long time. The Korean director fails to exhibit the essential characteristics of the Shamanism since he does not have enough knowledge toward the shaman ritual music in . However, the foreign director, who is a music herself, successively disclose the underlying beauty of Korean shaman ritual music and Korean traditional culture in .

• Journal of the Korean Orthopaedic Association
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• v.56 no.1
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• pp.26-33
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• 2021

Purpose: This study evaluated the results of dual plate fixation for periprosthetic femur fracture after total knee arthroplasty (TKA). Materials and Methods: From October 2007 to February 2013, 23 cases of periprosthetic femur fracture after TKA were treated at the author's hospital. There were 13 cases of fixation using a medial and lateral dual plate when the stability of the fracture site could not be achieved by one side fixation with a follow-up of more than one year. The cases included no loosening of the femoral component in fractures that were categorized as Lewis-Rorabeck classification II and supracondylar comminuted fractures and elongation of the fracture line to the lateral epicondyle of the femur or stem in the medullary canal. The mean age was 72 years (65-82 years), and 11 cases were female. Three cases had a stem due to revision. The mean bone marrow density was -3.2 (-1.7 to -4.4), and the mean period from primary TKA to periprosthetic fractures was 28 months (1-108 months). The mean follow-up period was 23 months (12-65 months). The medial fracture site was first exposed via the subvastus approach. Second, the supplementary plate was fixed on the lateral side of the fracture using a minimally invasive plate osteosynthesis technique. The average union time, complications, and Hospital for Special Surgery Knee Score (HSS) at the last follow-up were evaluated. Results: The mean union time was 17.4 weeks (7-40 weeks). Two cases showed delayed bone union and nonunion occurred in one case, in whom bone union was achieved three months later after re-fixation using a dual plate with an autogenous bone graft. The mean varusvalgus angulation was 1.67 degrees (-1.2-4.9 degrees), and the mean anterior-posterior angulation was 2.86 degrees (0-4.9 degrees) at the last follow-up. The mean knee range of motion was 90 degrees, and the HSS score was 85 points (70-95 points) at the last follow-up. Conclusion: Dual plate fixation for periprosthetic femur fractures that had not achieved stability by one side plate fixation after TKA showed a good clinical result that allowed early rehabilitation.