• The korean journal of orthodontics
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• v.49 no.2
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• pp.124-136
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• 2019

Orthodontic treatment is more complicated when both soft and hard tissues must be considered because an impacted maxillary canine has important effects on function and esthetics. Compared with extraction of impacted maxillary canines, exposure followed by orthodontic traction can improve esthetics and better protect the patient's teeth and alveolar bone. Therefore, in order to achieve desirable tooth movement with minimal unexpected complications, a precise diagnosis is indispensable to establish an effective and efficient force system. In this report, we describe the case of a 31-year-old patient who had a labio-palatal horizontally impacted maxillary left canine with a severe occlusal alveolar bone defect and a missing maxillary left first premolar. Herein, with the aid of three-dimensional imaging, sequential traction was performed with a three-directional force device that finally achieved acceptable occlusion by bringing the horizontally impacted maxillary left canine into alignment. The maxillary left canine had normal gingival contours and was surrounded by a substantial amount of regenerated alveolar bone. The 1-year follow-up stability assessment demonstrated that the esthetic and functional outcomes were successful.

• 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.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.382-389
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• 2020

Soil properties in opencast mines are a key factor in reclamation (revegetation) of mining areas. In this study we determined the soil physical and chemical properties of kaolinite tailings, reclaimed areas, and adjacent natural red pine (Pinus densiflora S. et Z.) forests in kaolinite opencast mines in Sancheong-gun, Gyeongsangnam-do. Six sites were chosen for collection of soil samples to determine soil physical and chemical properties at a soil depth of 10 cm. Soil bulk density was significantly higher (P < 0.05) in the kaolinite tailings (1.51 g·cm-3) than in the reclaimed areas (1.19 g·cm-3) and red pine forests (0.93 g·cm-3), whereas air phase in the kaolinite tailings (14.2%) was significantly lower than in the red pine forests (32.6%). Clay content in the red pine forests was significantly higher than in the reclaimed areas (18.7%) or kaolinite tailings (14.8%), whereas soil structural stability index was significantly lower in the reclaimed areas (1.61%) and kaolinite tailings (0.87%) than in the red pine forests (7.75%). Soil pH was significantly higher in the kaolinite tailings (pH 6.68) and reclaimed areas (pH 6.27) than in the red pine forests (pH 5.31). Soil organic carbon and total nitrogen were significantly higher in the red pine forests (C: 36.03 mg·g-1; N: 2.08 mg·g-1) than in the reclaimed areas (C: 5.00 mg·g-1; N: 0.31 mg·g-1) than in the kaolinite tailings (C: 2.12 mg·g-1; N: 0.07 mg g-1). The amount of available phosphorus was not significantly different among the three treatments. The concentration of exchangeable potassium was significantly lower in the kaolinite tailings (0.08 cmolc·kg-1) than in the reclaimed areas (0.21 cmolc·kg-1) and red pine forests (0.30 cmolc·kg-1). These results indicate that, because of high soil bulk density and low soil organic carbon, total nitrogen, available phosphorus, and exchangeable potassium in kaolinite tailings and reclaimed mining areas, soil nutrient management is needed in order to reclaim the vegetation in these type of areas.

• KIPS Transactions on Software and Data Engineering
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• v.9 no.12
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• pp.431-438
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• 2020

In this paper, the method to extract lip contour by multiple threshold is proposed. Spyridonos et. el. proposed a method to extract lip contour. First step is get Q image from transform of RGB into YIQ. Second step is to find lip corner points by change point detection and split Q image into upper and lower part by corner points. The candidate lip contour can be obtained by apply threshold to Q image. From the candidate contour, feature variance is calculated and the contour with maximum variance is adopted as final contour. The feature variance 'D' is based on the absolute difference near the contour points. The conventional method has 3 problems. The first one is related to lip corner point. Calculation of variance depends on much skin pixels and therefore the accuracy decreases and have effect on the split for Q image. Second, there is no analysis for color systems except YIQ. YIQ is a good however, other color systems such as HVS, CIELUV, YCrCb would be considered. Final problem is related to selection of optimal contour. In selection process, they used maximum of average feature variance for the pixels near the contour points. The maximum of variance causes reduction of extracted contour compared to ground contours. To solve the first problem, the proposed method excludes some of skin pixels and got 30% performance increase. For the second problem, HSV, CIELUV, YCrCb coordinate systems are tested and found there is no relation between the conventional method and dependency to color systems. For the final problem, maximum of total sum for the feature variance is adopted rather than the maximum of average feature variance and got 46% performance increase. By combine all the solutions, the proposed method gives 2 times in accuracy and stability than conventional method.

• Journal of the Society of Disaster Information
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• v.16 no.4
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• pp.813-823
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• 2020

Purpose: In order to maximize the stability and productivity of the work through simulation prior to high-risk facilities and high-cost work such as dismantling the facilities inside the reactor, we intend to use digital twin technology that can be closely controlled by simulating the specifications of the actual control equipment. Motion control errors, which can be caused by the time gap between precision control equipment and simulation in applying digital twin technology, can cause hazards such as collisions between hazardous facilities and control equipment. In order to eliminate and control these situations, prior research is needed. Method: Unity 3D is currently the most popular engine used to develop simulations. However, there are control errors that can be caused by time correction within Unity 3D engines. The error is expected in many environments and may vary depending on the development environment, such as system specifications. To demonstrate this, we develop crash simulations using Unity 3D engines, which conduct collision experiments under various conditions, organize and analyze the resulting results, and derive tolerances for precision control equipment based on them. Result: In experiments with collision experiment simulation, the time correction in 1/1000 seconds of an engine internal function call results in a unit-hour distance error in the movement control of the collision objects and the distance error is proportional to the velocity of the collision. Conclusion: Remote decomposition simulators using digital twin technology are considered to require limitations of the speed of movement according to the required precision of the precision control devices in the hardware and software environment and manual control. In addition, the size of modeling data such as system development environment, hardware specifications and simulations imitated control equipment and facilities must also be taken into account, available and acceptable errors of operational control equipment and the speed required of work.

• Journal of the Korean Geosynthetics Society
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• v.20 no.2
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• pp.23-33
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• 2021

In Korea, many reservoirs have been built for the purpose of solving the food shortage problem and supplying agricultural water. However, the current 75.6% of the reservoirs are in serious aged as more than 50 years have passed since the year of construction. In the case of such an aging reservoir, the stability due to scour and erosion inside the reservoir is very reduced, and if concentrated rainfall due to recent abnormal weather occurs, the aging reservoir may collapse, leading to a lot of damage to property and human life. Accordingly, each agency that manages aging reservoirs uses Ordinary Portland Cement (OPC) as an injection material and applies the grouting method. However, in the case of OPC, it may deteriorate over time and water leakage may occur again. And there are environmental problems such as consumption of natural resources and generation of greenhouse gases. So, there is a need to develop new materials and methods that can replace the OPC. In this study, an laboratory test and analysis were performed on the grout material developed to induce a curing reaction similar to that of OPC by recycling power plant byproduct. In addition, test in the field such as electric resistivity survey, Standard Penetration Test (SPT), and field permeability test were performed to analyzed to reinforcement effect and determine the possibility of using instead of OPC. As a results of the test, in the case of recycled power plant byproduct, the compressive strength was 2.9 to 3.2 times and the deformation modulus was 2.3 to 3.3 times higher, indicating that it is excellent in strength and can be used instead of OPC. And it was analyzed that the N value of the reservoir was increased by 1~2, and the coefficient of permeability (k) decreased to the level of 8.9~42.5%. showing sufficient reinforcing effect in terms of order.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.3
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• pp.61-77
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• 2011

This study focused on relevant rock names related to Sinsun(神仙) which had been settled as Taoist traces were combined with places. While interpreting major features of Sundoism relevant rocks, it also discussed types and places of rocks reflected in their names by considering distinct characteristics of landscape characters that ancestors viewed through the rocks or on the rocks. Conclusion of this study is summarized as follows. 1. Among the rock names related to Sinsun, the most frequently discovered one was Sinsunbawi(52) and followed by Sinsunbong(神仙峰: 38), Sinsundae(神仙臺: 31). Other than these, there were Gangsundae(降仙臺: 12), Sunyoodae (仙遊臺: 10) and Sasundae(四仙臺: 5). 2. In the name of Sinsundae, 'Dae(臺)' ascertains that it was located in greatly superb place in the aspects of viewpoint and appreciation where landscape superiority and overlook scenery were fair and outstanding. 3. Sinsunbong was named for a peak of mountain. At the same time, it implied a notion of worship with images of 'merging with sky' or 'looking up.' Most of time, Sinsunbong indicated the tallest rock in the mountain chain. 4. A significant number of Sinsunbong had names where legends of Sinsun's Go game or descent were originated from. It shows that 'Sinsun(仙) and Go game' used to be very important motives for folk etymology of Sinsun related rocks. Along with the Sinsundae, a number of Sinsunbawi were also turned out to exist in land and ocean with excellent marine view. 5. According to analysis of their altitudes and heights of the peaks where the rocks belong to, Sinsunbong, Sinsundae and Sinsunbawi were in order. It might indicate that the rocks were located on top of mountain or that Sinsunbong represented the mountain itself. Compared to this, Sinsundae was located in where distant panoramic views were overlooked. It was not necessarily to be in peak but in where with a great view like Taoist world. On the other hand, Sinsunbawi was located in where has fine scenery and great valley not so far from villages, which proved its name had been influenced by place feature not altitude. 6. Feature of rock with Sinsun related name is to comprise visual stability of worship object with close linkage to attitude of worshiper. Considering its deep connection with communicative method of worship object and worshiper, seemingly it was main factor to lead folk etymology of rocks with Sinsun related names. 7. Rock is an object with the greatest implication of Sinsun imagination and Sinsun rocks show most clearly the fact that Taoism, which used to be considered as inaccessible, had been actualized in a visual and realistic manner with the change of time.

• 한국노년학
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• v.30 no.1
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• pp.195-220
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• 2010

This study is to examine the job satisfaction of the social workers who manage the elderly care service in country, in order to find political alternatives and practical strategies for improving job satisfaction. The Factors to effect on job satisfaction are categorized as three groups ; personal factors, working environment factors and service related factors. The survey was conducted by 231 social workers who participated in a national seminar among 244 elderly care facilities in country, and 220 effective data were collected. Which factors effected on the job satisfaction of social workers and how much effected on it by them were mainly analyzed. The mean of job satisfaction status was 3.01, which was slightly higher than average(2.5). Men had higher job satisfaction than women. The unmarried than the married, permanent workers than contract workers, and workers who didn't execute other jobs had higher job satisfaction also. And The main factors which effected on job satisfaction were sex among personal factors, the manager willingness and not executing other jobs among working environment factors, and service attitude among service related factors. Particularly, the manager willingness was shown to effect on job satisfaction the most, and then service attitude, not executing other jobs and sex effected on it in order. The result showed that the elderly care facilities which had stronger manager willingness and better service attitude provided higher job satisfaction, and men who didn't execute other jobs than women had higher job satisfaction. The job satisfactions of payment and benefits, employment stability, appropriateness of working amount and working time, working environment and welfare conditions were lower than average. Therefore, the strategies to improve the lower job conditions are promptly required. Above all, the low payment strategy that has not been increased at all for 3 years has to be changed. In addition, it is important for the social workers not to execute other jobs as much as possible in order to reduce working amount and working time appropriately. In conclusion, it is required to try to improve the job satisfaction of the social workers who are the core of human service continually, which will make the elderly care service successful and effectiveness improved.

• (The)Study of the Eastern Classic
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• no.54
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• pp.319-348
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• 2014

This paper examines the centered on the Ritualized of Royal archery as a national event led to the demonstration of military rites was settled during the early Chosun Dynasty. And aims at considering of traditional of archery a Royal family and high position military people's. It was maintained as an system for both stability of royal family and centralization of government authority. As we know, since ancient times, the performance number of shooting arrows had been reduced in the early Chosun Dynasty. And one more reason is, traditionally Royal family liked shooting archery. For example, King Taejong was very openly shooting archery to inside palace and outside field. He says the archery is a principal element of military persons. Anyhow, to the King Jungjong, many Kings played shooting archery. However, at that time, the Royal archery came from ancient Korea and Kingdom of Koryo. In this historical background, Military rites will be established not just from ancient China. It specially called five manner of rituals. However, the rule of Confucianism to be Government police, archery ritual was declined. It's involved Curriculum of education. And this is related to the who got the new group of government authority. They are young confucianist. From there, the Confucianism manners, were to change of traditional of archery in Early Chosun Dynasty.

• The Southeast Asian review
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• v.28 no.1
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• pp.21-51
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• 2018

This article takes several approaches in explaining recent developments in Vietnam. First, it draws upon an array of sources that idealize Vietnam's embrace of capitalism and integration into the global market in order to sketch out its economy's progress in 2017. Second, it observes, evaluates, and diagnoses recent changes in the Vietnamese economy in the medium to long term by incorporating conflicting perspectives on Vietnam's performance as a capitalist country. Third, this article traces the power shifts that have risen from internal struggles in the Communist Party over political and social issues. Fourth, it elaborates on the aforementioned impact that foreign relations have had on socio-political developments in Vietnam, as well as the government's response. In so doing, it also attempts to evaluate, however briefly, the significance of the 25th anniversary of South Korea-Vietnam relations. Finally, it examines the public's reaction to the post-reform transitions in light of recent sociocultural changes. 2017 was a memorable year for Vietnam: a continuous march toward capitalism; the resulting expansion of the Vietnamese people's demands; political controversies and government control; the looming instability of United States-China relations and various attempts to address the situation. These events will inevitably replicate themselves in the future as the ostensibly socialist Vietnam adopts a capitalist model. The problem is that it is unclear whether these experiences will continue with the consent of the people of socialist Vietnam or engender resistance. It is difficult to achieve meaningful consent in the status quo of worsening inequalities, widespread corruption, monopoly on power, and sustained use of unskilled low-wage workers. In other words, when concerns such as welfare, public health, and the environment are set aside in favor of economic development and commercialization as they have been, discontent, rather than consent, will prevail. It is thus important to keep a watchful eye on the viability of the nominal economic growth, surface-level political stability, and strategic responses to foreign relations that took place in 2017.