• Tribology and Lubricants
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• v.37 no.4
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• pp.129-135
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• 2021

An air-bearing stage uses externally pressurized air as the lubricant between the stage and the rail. The supporting force generated by the supplied air makes the stage rise and move smoothly with extremely low friction. Mechanical contacts rarely happen, the bearing surfaces do not produce wear particles, and dust is not generated. It also has the advantage of having low energy loss and high precision. Because of its advantages, an air-bearing stage is used in several types of machines that require high precision. In this article, the effect of the pocket depth on the hammering phenomena of the air bearing is studied. An analysis program is developed to calculate the dynamic behavior of the stage by solving the Reynolds equation between the stage and the guideway and the equations of motion on the stage. The acceleration, constant movement, and deceleration are applied to the stage. The stage is modeled as a five-degree-of-freedom system. In the course of the dynamic behavior, the hammering phenomena occur under some special conditions. The deeper the pocket, the more unstable the behavior of the stage, and air hammering occurs when it exceeds a certain depth. In addition, the higher the supply pressure, the more unstable the behavior of the stage. However, hammering occurs even with a shallow pocket depth. Other conditions that affect the hammering phenomena are calculated and discussed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.4
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• pp.33-47
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• 2022

Wild boars(Sus scrofa) are expanding their range of behavior as their habitats change. Appearing in urban centers and private houses, it caused various social problems, including damage to crops. In order to prevent damage and effectively manage wild boars, there is a need for ecological research considering the characteristics and movement characteristics of wild boars. The purpose of this study is to analyze home range and identify land cover types in key areas through tracking wild boars, and to predict the movement connectivity of wild boars in consideration of previous studies and their preferred land use characteristics. In this study, from January to June 2021, four wild boars were captured and tracked in Jinju city, Gyeongsangnam-do, and the preferred land cover type of wild boars was identified based on the MCP 100%, KDE 95%, and KDE 50% results. As a result of the analysis of the home range for each individual, it was found that 100% of MCP was about 0.68km², 2.77km², 2.42km², and 0.16km², and the three individuals overlapped the home range, refraining from habitat movement and staying in the preferred area. The core areas were analyzed as about 0.55km², 2.05km², 0.82km², and 0.14km² with KDE 95%., and about 0.011km², 0.033km², 0.004km², and 0.003km² with KDE 50%. When the preferred land cover type of wild boar was confirmed based on the results of analysis of the total home range area and core area that combined all individuals, forests were 55.49% (MCP 100%), 54.00% (KDE 95%), 77.69% (KDE 50%), respectively, with the highest ratio, and the urbanization area, grassland, and agricultural area were relatively high. A connectivity scenario was constructed in which the ratio of the land cover type preferred by the analyzed wild boar was reflected as a weight for the resistance value of the connectivity analysis, and this was compared with the connectivity evaluation results analyzed based on previous studies and wild boar characteristics. When the current density values for the wild boar movement data were compared, the average value of the existing scenario was 2.76, the minimum 1.12, and the maximum 4.36, and the weighted scenario had an average value of 2.84, the minimum 0.96, and the maximum 4.65. It was confirmed that, on average, the probability of movement predictability was about 2.90% better even though the weighted scenario had movement restrictions due to large resistance values. It is expected that the identification of the movement route through the movement connectivity analysis of wild boars can be suggested as an alternative to prevent damage by predicting the point of appearance. In the future, when analyzing the connectivity of species including wild boar, it is judged that it will be effective to use movement data on actual species.

• Korean journal of applied entomology
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• v.50 no.1
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• pp.1-6
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• 2011

Movement of adult Monochamus alternatus was investigated on young black pine, Pinus thunbergii, trees for about one month in a screen cage. Number of pine trees to which M. alternatus females and males moved during the experimental period was $6.4{\pm}1.4$ and $7.2{\pm}1.5$ out of 15 trees, respectively. Adult females and males moved to $0.2{\pm}0.1$ and $0.3{\pm}0.1$ tree per day, respectively. A 74.6 and 80.7% of adult females and males moved at night (17:00-08:00) to other trees. After moving, most beetles (72.6% of females and 76.0% of males) stayed on the tree to which they moved for one to two days. Some beetles stayed for up to seven days.

• Journal of the Korean Geotechnical Society
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• v.15 no.5
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• pp.259-279
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• 1999

Model tests on propped retaining walls were performed for the investigation of wall displacement, distribution of earth pressure, surface settlement and underground movement at various excavation stage in sand. The result of model tests on the trough of surface settlement showed considerable difference depending on the characteristic of wall stiffness, wall friction and soil condition. The location of maximum underground movement were found to be at range of 0.15H to 0. 1H(H: Final excavation depth). Effect of arching by the redistribution of earth pressure were closely related to the stiffness of wall as well as the soil condition. The wall displacement and earth pressure distribution were simulated by elasto - plastic beam analysis program and finite element method with GDHM model respectively. The result of elasto-plastic analysis showed some discrepancy on the wall displacement and earth pressure, but result of underground movement by FEM with various wall stiffness were in good agreement with the model tests.

• Journal of the Korean Geotechnical Society
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• v.20 no.8
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• pp.15-27
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• 2004

Sliding aspects of rock slope, where large-scaled tension cracks are induced during preliminary excavation, have been analyzed. Structure of rock mass is investigated by performing the electrical resistivity survey and the orientations and positions of discontinuities are measured from DOM-drilled core log. Geological evidence far primary failure movement has been detected and clay minerals which possess swelling properties are identified through XRD analysis. Slope stability is examined by considering the orientations of discontinuities and their trace distributions on the cut-face and neighboring natural slope surface. Both orientations and positions of failure-invoking discontinuity planes, traces of which are exposed within the anticipated sliding region, are concerned fur analyzing the preferred sliding directions. Regional sliding vectors are assessed based on the relative positions of potential sliding planes in the boreholes and the general trend of anticipated failure movement of rock slope is also investigated.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.3
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• pp.276-280
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• 2008

Many dissemination protocols on the mobility support in wireless sensor networks have been designed based on the assumption that the movement trace of sinks, such as soldiers and fire fighters, is random. However, the mobility of the sinks in many applications, for example, the movement trace of a soldier on operation in a battle field, can be determined in advance. In this paper, we propose a Predictable Mobility-based Data Dissemination protocol that enables data to directly route from source nodes to moving sinks by taking into consideration predictable movement behavior of the sinks. We also show the superiority of the predictable mobility-based data dissemination protocol through the performance comparison with the random mobility-based data dissemination protocols.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.68-74
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• 2011

Rett syndrome is a X-linked genetic neurological disorder characterized by developmental regression, particularly in relation to expressive language and use of the hands, together with profound mental retardation, that almost exclusively affects females. Oral manifestations of the disease are commonly associated with the clinical conditions such as convulsion activity, difficulties for oral hygiene behavior, walking problems and oral/digitalmanual habits. Bruxism is the most frequently observed oral habit in patients with Rett syndrome. Two cases with the Rett syndrome were reported. Both patients had the typical manifestations like stereotypic hand movement, bruxism and digit-hand sucking. Caries control for the patients was perfomed under general anesthesia.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.773-790
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• 2009

The Korea high speed train was launched from Seoul to Busan of 1st construction phase at 1st April, 2004. This huge project will be lead to a great change in korean society such as existing mode choice behavior change and the concentrating on KTX station zone lifestyle pattern's change. With the result to opening high speed train railway was diminished train journey time between Seoul to Busan from 4 hours 10 minute to 2 hours 40 minutes, and has been change population movement, favorite location of corporation headquarters, existing metropolitan transportation pattern and so on. In the middle of this study, I choose to analyse Seoul-Cheonan/Asan stations, Seoul-Deajeon stations, Seoul-Deagu stations, Seoul-Pusan stations. This study have a information to analyse among as like movement of population, status of employee structure, usage of land, movement inland transportation mode. I sure that this study will lead to helpful prediction both 2nd phase of Kyoung-bu high-speed railway and Ho-nam high-speed railway in advance.

• Structural Engineering and Mechanics
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• v.86 no.6
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• pp.739-750
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• 2023

This study examines the two-level behavior of the toggle brace damper within a steel frame having a yielding pipe damper and rotational friction damper. The proposed system has two kinds of fuse for energy dissipation in two stages. In this mechanism, rotational friction damper rather than hinged connection is used in toggle brace system, connected to a pipe damper with a limited gap. In order to create a gap, bolted connection with the slotted hole is used, such that first a specific movement of the rotational friction damper solely is engaged but with an increase in movement, the yielding damper is also involved. The performance of the system is such that at the beginning of loading the rotational friction damper, as the first fuse, absorbs energy and with increasing the input load and further movement of the frame, yielding damper as the second fuse, along with rotational friction damper would dissipate the input energy. The models created by ABAQUS are subjected to cyclic and seismic loading. Considering the results obtained, the flexibility of the hybrid two-level system is more comparable to the conventional toggle brace damper. Moreover, this system sustains longer lateral displacements. The energy dissipation of these two systems is modeled in multi-story frames in SAP2000 software and their performance is analyzed using time-history analysis. According to the results, permanent relocations of the roof in the two-level system, in comparison with toggle brace damper system in 2, 5, and 8-story building frames, in average, decrease by 15, 55, and 37% respectively. This amount in a 5-story building frame under the earthquakes with one-third scale decreases by 64%.

• Parasites, Hosts and Diseases
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• v.58 no.3
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• pp.267-278
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• 2020

The heterogeneity and complexity of malaria involves political and natural environments, socioeconomic development, cross-border movement, and vector biology; factors that cannot be changed in a short time. This study aimed to assess the impact of economic growth and cross-border movement, toward elimination of malaria in Yunnan Province during its pre-elimination phase. Malaria data during 2011-2016 were extracted from 18 counties of Yunnan and from 7 villages, 11 displaced person camps of the Kachin Special Region II of Myanmar. Data of per-capita gross domestic product (GDP) were obtained from Yunnan Bureau of Statistics. Data were analyzed and mapped to determine spatiotemporal heterogeneity at county and village levels. There were a total 2,117 malaria cases with 85.2% imported cases; most imported cases came from Myanmar (78.5%). Along the demarcation line, malaria incidence rates in villages/camps in Myanmar were significantly higher than those of the neighboring villages in China. The spatial and temporal trends suggested that increasing per-capita GDP may have an indirect effect on the reduction of malaria cases when observed at macro level; however, malaria persists owing to complex, multi-faceted factors including poverty at individual level and cross-border movement of the workforce. In moving toward malaria elimination, despite economic growth, cooperative efforts with neighboring countries are critical to interrupt local transmission and prevent reintroduction of malaria via imported cases. Cross-border workers should be educated in preventive measures through effective behavior change communication, and investment is needed in active surveillance systems and novel diagnostic and treatment services during the elimination phase.