• The Journal of Engineering Geology
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• v.32 no.2
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• pp.209-219
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• 2022

To experimentally investigate the variation of soil characteristics in slope during rainfall and the shape of slope failure, the model test was performed using soil box and artificial rainfall simulator. The model test of slope formed by the homogenous sand was performed, and the saturation pattern in the model slope due to rainfall infiltration was observed. The slope model with the inclination of 35° was set up on the slope of 30°, and the rainfall intensity of 50 mm/hr was applied in the test. The soil depth of 35 cm was selected by considering the size of soil box, and the TDR (time domain reflectometry) sensors were installed at various depths to investigate the change of soil characteristics with time. As the result of model test, the slope model during rainfall was saturated from the soil surface to the subsurface, and from the toe part to the crest part due to rainfall infiltration. That is, the toe part of slope was firstly saturated by rainfall infiltration, and then due to continuous rainfall the saturation range was enlarged from the toe part to the crest part in the slope model. The failure of slope model was started at the toe part of slope and then enlarged to the crest part, which is called as the retrogressive failure. At the end of slope failure, the collapsed area increased rapidly. Also, the mode of slope failure was rotational. Meanwhile, the slope failure was occurred when the matric suction in the slope was reached to the air entry value (AEV) estimated in soil-water characteristic curve (SWCC).

• Journal of Space Technology and Applications
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• v.1 no.1
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• pp.64-75
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• 2021

On the moon as well as the earth, one of the easiest ways to understand geological formation history of any region is to observe the stratigraphy if it is available, the order in which the strata build up. By analyzing stratigraphy, it is possible to infer what geological events have occurred in the past. Mare Nubium also has an unique normal fault called Rupes Recta that shows stratigraphy. However, a rover moving with wheels is incompetent to explore the cliff since the Rupes Recta has an inclination of 10° - 30°. Therefore, a quadruped walking robot must be employed for stable expedition. To exploration a fault with a four-legged walking robot, it is necessary to design an expedition route by taking account of whether the stratigraphy is well displayed, whether the slope of the terrain is moderate, and whether there are obstacles and rough texture in the terrain based on the remote sensing data from the previous lunar missions. For the payloads required for fault surface exploration we propose an optical camera to grasp the actual appearance, a spectrometer to analyze the composition, and a drill to obtain samples that are not exposed outward.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2C
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• pp.133-142
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• 2006

Many methods have been tried to more correctly measure rock joint roughness. However, true roughness may be distorted and underestimated due to the sampling interval and measurement method. Thus, currently used measurement methods produce a dead zone and distort roughness profiles. The purpose of this study is to suggest new roughness measurement method by a camera-type 3D scanner as an alternative of currently used methods. First, the underestimation of artificial roughness is analyzed by using the current measurement method such as laser profilometry. Second, we replicate eight specimens from two rock joint surfaces, and digitize by a 3D scanner. Then, the roughness coefficient values obtained from eight numbers of 3D surface data and from three hundred twenty numbers of 2D profiles data are analyzed by using current and new measurement methods. The artificial simulation confirms that the sampling interval is one of main factors for the distortion of roughness and shows that inclination of waviness may not be considered any current methods. The experimental results show that the camera-type 3D scanner produces 10% larger roughness values than current methods. As the proposed new method is a fast, high precision and more accurate method for the roughness measurement, it should be a promising technique in this area.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1C
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• pp.1-9
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• 2009

In this study, the influence of wetting band depth by continuous rainfall and the magnitude of wetting front suction on the stability of slopes in weathered soils were investigated by using finite element programs SEEP/W and SLOPE/W. Three different intensities of rainfall (10mm/hr, 30mm/hr, 50mm/hr) were chosen, and the total duration of rainfall was 96 hours. Three infinite slopes with the inclination of 1:1.5 and 1:1.8, 1:2.0 were considered and the typical properties and the shear strength parameters of the weathered soil were applied. It is shown that rainfall duration plays an important role in slope stability. Based on the analytical results, it is found that as the rainfall duration increases, the wetting band depth also increases. Also, the increasing rate of the wetting band depth was decreased as the soil density was increased. These results come from the decrease of the coefficient of permeability and the increase of the soil suction. Finally, it is also shown that the safety factors of slopes by unsaturated analysis are mostly larger than those by saturated analysis. Therefore, commonly used saturated analysis may substantially underestimate the degree of safety factor in realistic situations.

• Tunnel and Underground Space
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• v.34 no.1
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• pp.1-14
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• 2024

An image-reconstruction technology, involving the deployment of an unmanned mobility equipped with high-speed LiDAR (Light Detection And Ranging) has been proposed to reconstruct the shape of abandoned mine. Unmanned mobility operation is remarkably useful in abandoned mines fraught with operational difficulties including, but not limited to, obstacles, sludge, underwater and narrow tunnel with the diameter of 1.5 m or more. For cases of real abandoned mines, quadruped robots, quadcopter drones and underwater drones are respectively deployed on land, air, and water-filled sites. In addition to the advantage of scanning the abandoned mines with 2D solid-state lidar sensors, rotation of radiation at an inclination angle offers an increased efficiency for simultaneous reconstruction of mineshaft shapes and detecting obstacles. Sensor and robot posture were used for computing rotation matrices that helped compute geographical coordinates of the solid-state lidar data. Next, the quadruped robot scanned the actual site to reconstruct tunnel shape. Lastly, the optimal elements necessary to increase utility in actual fields were found and proposed.

• Science of Emotion and Sensibility
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• v.27 no.2
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• pp.15-24
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• 2024

Previous studies on texture and emotion have focused on identifying precisely which tactile stimuli trigger specific emotions. Despite the significant role of vision in tactile perception, research has so far only focused on the singular aspect of texture. In this study, we used tactile stimuli to investigate the effects of three variables-roughness, hardness, and visual blocking-on the affective responses to tactile perception. The experimental stimuli that can be encountered in daily life were selected based on the four conditions of "rough/hard," "rough/soft," "smooth/hard" and "smooth/soft" by crossing two roughness conditions (rough, smooth) and two hardness conditions (hard, soft). The experiment was divided into two sessions depending on whether or not visual blocking existed. Participants completed a session in which they evaluated a tactile stimulus after touching it without seeing it and then proceeded with a session in which they evaluated a stimulus after touching it with sight of it. The results of the repeated-measures ANOVA showed that individuals reported a more positive perception when touching stimuli with visual cues and more negative when touching stimuli without visual cues. Furthermore, the inclination to perceive smooth and soft stimuli more positively and rough stimuli more negatively was stronger when touching without visual cues. The results of this study suggest implications for enhancing the understanding of the interaction between emotion and visual information processing by elucidating how emotions are experienced differently in situations where visual information is provided and where it is not.

• Journal of Family Resource Management and Policy Review
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• v.28 no.2
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• pp.51-63
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• 2024

This study aimed to identify the factors influencing the intentions of employed married women, aged 19 and above, with no prior experience of childbirth, to give birth to their first child. First, the intention of employed married women to give birth to their first child showed a moderate level of inclination, with slightly higher scores reflected in the subvariables of perceived marital value and perceived child value both within family values, while the effect of perceived gender role value was generally higher than the midpoint. Perception of work-life balance was generally a moderate influence, with the subvariable of balancing work and family being slightly higher than the midpoint in terms of influence. Second, the intention to give birth to a first child was clearly associated with the level of education and showed a positive correlation. However, this intention was negatively correlated with age, perceived child values, perceived marital values, and residential tenure. Third, pregnancy intention was influenced by age, educational level, perceived value of children, perceived value of marrriage, and work-life balance. This study provides meaningful assistance in understanding current low birth rate by gathering data on the preferences of married working women in relation to childbirth and by presenting the diverse perspectives of the women.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.855-864
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• 1998

The purposes of this study were to evaluate the cephalometric characteristics of Korean female patients with Class II division 2 malocclusion and to compare Korean females with Caucasian females who had same type of malocclusion. All of the samples had Class II division 2 malocclusion with deep overbite (more than 4mm) and full permanent dentition. These samples were divided into two groups according to the races: Group 1(N=16; Korean females; average age=18Y 2M) and Group 2 (N:20; Caucasian females; average age=14Y 2M). The pretreatment lateral cephalograms were measured, analyzed and compared by using 38 variables and independent t-test. And the results were as follows: 1. Although there were no differences in Overbite, SN to mandibular plane angle, Palatomandibular plane angle, and FMA between Group 1 and 2, the other vertical relation variables of maxilla and mandible (SN to palatal plane angle, SN to occlusal plane angle, ODI) of Group 1 showed more clockwise rotation tendency of occlusal plane and less hypodivergency tendency than those of Group 2. 2. There were no differences in mandibular body length and ramus height between Group 1 and 2 except small upper genial angle of Group 1. There was less counterclockwise rotation tendency of mandible in Group 1. 3. There were no statistical significant differences in UAFH/LAFH and PFH/AFH between Group 1 and 2. 4. Although there were no differences of overjet and anteroposterior position of mandible between Group 1 and 2, the position of maxilla of Group 1 was more retropositioned than that of Group 2. 5. Except the more protrusion of lower incisor to A-Pog of Group 1, there were no differences of inclination and distance of upper and lower incisors to basal plane between Group 1 and 2. 6. The distance from upper- first molar to palatal plane showed no difference between Group 1 and 2. But the distance from lower first molar to mandibular plane of Group 1 was greater than that of Group 2. So it may be partially related to the clockwise rotation of occlusal plane and the less counterclockwise rotation tendency of mandible of Group 1. 7. Group 1 had more protrusive upper and lower lips than Group 2.

• Korean journal of communication and information
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• v.34
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• pp.132-160
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• 2006

The main purpose of this study is based on the comparative analysis over news framing of the family headship(Hoju) abolition in Korean society. This study examined the newspaper articles involving the Hoju abolition, which had been printed on the three major dailies, Chosun, Kukmin, Hankyoreh through February of 1990 to July of 2005. First, the news articles were analyzed and classified on the basis of their lengths, news types, main characters, news framing and systematic framing. Second, the articles that this study looked into were divided into the five major periods when the issue of the Hoju abolition in Korean society surfaced as a main social agenda to be discussed. Third, the main differences between the noticeable frame and unnoticeable frame in each period were analyzed through the three different perspectives which can also can be sub-divided into the six different attributes. This study found that the Hoju abolition as an attribute had developed into political, legal and social fields. The analysis of the research shows that the articles related to the patriarchy abolition showed more dominant frame which reflected the social change or the general tendency of the times. However, the analysis indicates that the articles in the level of an attribute included more dominant frame which mirrored a male chauvinism society. It also points out that the articles contained more dominant frame which was be used as a standard to find out the readers' political inclination. The articles also showed the dominant frame which included the revision and legal process of family laws before presidential or general election campaigns. The study also found that there were major differences among the three dailies. First of all, Chosun, regarded the Hoju as a custom by stressing that 'it is necessary to keep Hoju system to intensify the role and crisis of family if the Hoju will be abolished'. However, Hankyoreh recognized the issue as an important one to improve feminism and female rights by maintaining that 'it is the time to balance the inequality out between men and women with the abolition of patriarchy'. Finally, Kukmin treated the issue as an first step to acknowledge the dignity of females by emphasizing that 'a revision of the law is essential to accept the changing ethics of the times'.

• (The)Study of the Eastern Classic
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• no.36
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• pp.203-228
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• 2009

ChaeHo Shin's major interests were in the ancient history, among other periods of the Korean history. Shin's depiction of history is characterized by having nation in the heart of history, whose tendency of nationalism was purposefully strong. In general, the nationalism of those times was emphasizing a 'strong' nation, just as in the case of Shin's theory, and at the same time stood for the theory of social evolution with a view to raising the nation in the front line of history. The nationalism, in association with the theory of social evolution, ended up having a propensity that criticizes imperialism on the one hand, and envies it on the other. This inclination is literally shown in Doksasillon (A New Guide to Reading History), which is ChaeHo Shin's research on the ancient history. Doksasillon is a historical essay that was published serially in 50 installments from August 27th through December 13th in 1908. Unlike the existing views in the late 1900s on the ancient history, among other ages of the Korean history, Doksasillon can be called a treatise with a focus on nation. Doksasillon is an incomplete study which can be divided into two parts, introduction and ancient times that is the first volume. It, nevertheless, shows the aspect of a powerful nation activist who tried to surmount the life-and-death crisis of nation by 'recalling' the nation in the period of the late-Joseon and the Korean empire in 1908 and 'rediscovering' the territory. It also reflects a slice of a historian's anguish that attempted to cope with the national crisis by virtue of the 'power' of history. It is ChaeHo Shin who 'rediscovered' the Buyeo tribe as the mainstream of the ancient history of Korea, and recomposed and materialized the ancient history. Shin chose the 'Buyeo tribe' as a principal race, and used it as a representative of the Korean nation in the ancient era, which was because Buyeo and Goguryeo were the strongest. The emphasis laid on the powerful nation in the history of Korea well reflects the efforts of a powerful nation activist in the age of the late-Joseon, and on the other hand, it shows how nationalism came to be formed in Korea. ChaeHo Shin is regarded as a person who lived in the age in which nationalism, which underscores the homogeneity of a nation, had to be stressed as a sole weapon for a nation who was left behind in modernization and whose rights were disseized. Dosasillon shows a process of reconstructing the history of DanKun and the Buyeo tribe and unearthing a hero who was valued as a savior of the nation, which was the reason that ChaeHo Shin wrote a history.