• East Asian mathematical journal
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• v.35 no.1
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• pp.41-50
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• 2019

This paper is dealt with one-dimensional elliptic jumping problem with nonlinearities crossing n eigenvalues. We get one theorem which shows multiplicity results for solutions of one-dimensional elliptic boundary value problem with jumping nonlinearities. This theorem is that there exist at least two solutions when nonlinearities crossing odd eigenvalues, at least three solutions when nonlinearities crossing even eigenvalues, exactly one solutions and no solution depending on the source term. We obtain these results by the eigenvalues and the corresponding normalized eigenfunctions of the elliptic eigenvalue problem and Leray-Schauder degree theory.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.85.2-86
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• 2015

The YORP effect is non-gravitational force that changes the spin-status of asteroid. So far this effect has been directly detected only from the Near-Earth asteroids (Taylor et al. 2007; Lowry et al. 2007, 2014; Breiter et al. 2011; Durech et al. 2008, 2012). Pravec at el. 2008 found the evidences for changing spin rate of small asteroids (3 - 15 km) by the YORP effect in the Main-Belt and Mars-crossing asteroids. The Mars-crossing asteroids (1.3 < q < 1.66 AU) are objects that cross orbit of the Mars. The Mars-crossing asteroids are regarded as one of the main sources for the Near-Earth asteroids. We expect that rotation of Mars-crossing asteroids would be influenced by the YORP effect. We try to search observational evidence of the YORP effect for the Mars-crossing asteroid. Our target 2078 Nanking is a population of the Mars-crossing asteroid. First light-curve of 2078 Nanking was obtained from Mohamed et al. 1994, and Warner et al. 2015 recently published new observational data. We observed this asteroid on 26th Nov. 2014 and 17th Jan. 2015 using SOAO (Sobaeksan Optical Astronomy Observatory) 0.61 m telescope with 4K CCD. Using light-curve inversion method (Kaasalainen & Torppa 2001; Kaasalainen et al. 2001), we try to determine the pole orientation and shape model of this asteroid based on the combination of our light-curve and literature photometric data. Knowing spin parameters, such as rotational period and spin axis, are essential for studying the YORP effect. In this presentation, we provide some preliminary results of our recent study: light-curve and processing of shape modeling of 2078 Nanking. We plan to find observational clue for the YORP effect on the Mars-crossing asteroids.

• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.136-141
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• 2018

The purpose of this study is to compare the bird crossing of roads by type (Expressway 1, railroad-provincial road and Highway 4) and the crossing of roads according to the size of birds. The greatest number of avian species and individuals crossing road per 10 minutes were found on railroad-provincial road ($8.96{\pm}1.92$ and $29.33{\pm}11.94$, respectively), while the lowest number of avian species and individuals were found on Expressway 1 ($2.96{\pm}1.04$ and $6.13{\pm}2.89$, respectively), which has the widest width. In addition, the number of small-sized bird (<20 cm) crossing the Expressway 1, railroad-provincial road, and Highway 4 was lower than that of the medium-sized bird (${\geq}20cm$). Current wildlife crossing structures have been focused on mammals, amphibians and reptiles, but future structures should also consider birds.

• Journal of the Korean Society for Railway
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• v.8 no.2
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• pp.145-154
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• 2005

Traffic accidents at highway-rail crossing result in larger social and economic damages than the accidents at the typical highway intersections. The traditional control and warning systems of the highway-rail crossing have limitations in that 1) they do not recognize the differences of the trains' arrival times because they rely on the distance-based control system, rather than the time-based one, and 2) thereby they usually cause longer delays of vehicles and pedestrians at the highway-rail crossings. The objective of this study is to develop a time-based railroad crossing control system which takes into account the speed and expected arrival time of trains. using the spot speeds and acceleration rates of trains measured at three points, the developed system was found to be able to accurately estimate the arrival time of train. VISSIM simulation package was utilized to compare system effect of the developed time-based railroad crossing control system with that of the conventional distance-based one. It was found that the developed time-based railroad crossing control system reduced the average travel time, maximum delay length, average delay time, and average number of stop-experienced vehicles as much as 7.0$\%$, 75.6$\%$, 12.7$\%$, and 60.0$\%$, respectively, compared with those from the conventional distance-based one.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.1
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• pp.139-150
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• 2019

PURPOSE: This study was conducted to determine the effects of treadmill gait training with obstacle-crossing on the static and dynamic balance ability of patients with post stroke hemiplegia. METHODS: Twenty-one patients with post stroke hemiplegia were divided into three groups as: treadmill gait training with obstacle-crossing (TOG, n=7), treadmill gait training without obstacle-crossing (TGG, n=7) and a control (CON, n=7). TOG and TGG performed exercise for 20 minutes, three times a week for 8 weeks. Static balance ability (stability typical, ST; weight distribution index, WDI; fourier harmony index, FHI; and fall index, FI) and dynamic balance ability (berg balance scale, BBS and timed up and go test, TUG) were measured before and after 8 -weeks in each exercise group. Statistical analyses were conducted using two-way ANOVA with repeated measures, a paired t-test, and multiple comparisons according to Tukey's HSD. RESULTS: FHI and BBS were significantly increased at TOG (p<.01) and TGG (p<.05) after 8-weeks compared to before treadmill gait training with obstacle-crossing. FHI and BBS were significantly increased at TOG compared with CON and TGG (p<.05). CONCLUSION: Treadmill gait training with obstacle-crossing was more effective than that without obstacle-crossing to improve posture control and independent daily life performance of hemiplegia patients.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.634-636
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• 2008

This paper proposes a frequency detection method based on an advanced zero-crossing technique. Zero-crossing method for detecting frequency is one of the most widely used methods today. Although it is simple to apply, it requires extra hardware in implementation due to its limitations in accuracy. The proposed method models the error generated during zero crossing linearization and compensated for it in real time which makes it simple and accurate. The validity of the method and its applicability in anti-islanding detection of distributed generators was confirmed through simulation.

• Journal of The Korean Digital Architecture Interior Association
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• v.11 no.4
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• pp.39-46
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• 2011

This Study is about the Axis used for creating forms of interior spaces in representative works of Peter Eisenman architecture. The plans, elevations, photos of interior spaces of his architecture were collected and analysed. In conclusion, the methods using axises were classified in the axises crossing right angle and the rotating axises crossing right angle. The rotating axis were divided into one-angle rotating and multi-angle rotating. The axises were rotated on the plan or rotated on the elevation. The axises crossing right angle were used for dividing, assembling, transforming and composing different proportions of rectangles in interior spaces. The rotating axises crossing right angle were used for creating divers forms such as triangle, quadrilateral, and polygon. The one-angle rotating emphasizes directions of axises in interior spaces. The multi-angle rotating emphasizes decentered directions in interior spaces. The parts created while crossing axises three-dimensionally were opened or filled. The axises were used dynamically and three-dimensionally for diversity of forms in interior spaces of Peter Eisenman architecture.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.655-660
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• 2005

Recently, the crossing tunnel has been constructed to maintain the operation highway as well as railroad. The advantages of adopting RPS method in crossing tunnel construction are needed a little space and easy to change the direction of cutting shoe during the construction of pipe roof. The numerical analysis of RPS was performed for the application in the crossing tunnel under railroad. The earth pressure distribution and settlement were predicted when the RPS method was applied during the excavation for crossing tunnel construction.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.225-227
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• 1995

An object detection algorithm using a modified IDM(Image Differential Method) is proposed for detecting an object in a level crossing area. The conventional object detection method using LASER light has the deadzone that it cannot detect small objects, while the object detection method using image data in a level crossing area can detect such small objects. But the image data in a level crossing area can be changeable easily because the data is outdoor and sensitive to such surrounding environments as the change of the sun beam, the shadow of cars, and so on. So we resolve these problems by adding the normalization and the process for shadow of the image data in a level crossing area to the basic IDM(Image Differential Method).

• Journal of the Korean Society for Railway
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• v.5 no.2
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• pp.125-132
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• 2002

As the public use part of the railway and the road, the railway crossing is important to work properly by two transportation means. Also, It is important to provide the good face of friction on the railway crossing in aspect of protecting the railway crossing accident. Lately, the material of railway crossing panel is the wood, the asphalt, and the steel. As they have a various fault, it was studied to analyze the structural action of the new material, rubber panel. This paper analyzed eigenvalue, stress and displacement by truck passing weight, thermal stress and train moving weight, using the Finite Element Method model