• Journal of Ecology and Environment
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• v.35 no.3
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• pp.189-194
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• 2012

Coarse woody debris (CWD) is generally considered dead woody material in various stages of forest decomposition and has been hypothesized to be an important habitat feature for mammals in forests of the Pacific Northwest, USA. Sherman and pitfall trapping were conducted for 2 years on three paired sites with low and high amounts of CWD. Deer mice was the dominant species with a total capture of 605 (45.6%). Four species of insectivores were captured, including Sorex moncicolus, S. trowbridgii, S. vagrans, and Neurotrichus gibbsii. A Poisson regression model was used to test whether 11 CWD variables could predict insectivore captures. The volume of logs and mean decay were important variables for deer mice use of CWD. Mean distance from pieces of CWD to the capture point was significantly related to the total number of captures of trowbridge shrew (Sorex trowbridgii) and all insectivore species. Vagrant shrews (Sorex vagrans) were significantly associated with log volume. Retaining large size CWD should be part of a management plan for ground-dwelling insectivores in forests to secure their biodiversity.

• Journal of the Korean Solar Energy Society
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• v.29 no.5
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• pp.20-27
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• 2009

The effect of borehole thermal resistance on the borehole length is studied. In performing this work a new concept BLRR(borehole length reduction rate) is developed based on the line source model. The solution of line source model is shown to be valid through the comparison with the data of thermal response test. It is shown that BLRR is a function of soil thermal conductivity(k) and borehole thermal resistance($R_b$). The value of BLRR increases with increasing k, which means reducing $R_b$ is more effective when k is high. The reduction of borehole length with change of $R_b$ is easily estimated with BLRR. The validity of BLRR is also examined with EED analysis.

• Journal of the military operations research society of Korea
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• v.13 no.1
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• pp.19-27
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• 1987

This paper deals with the development of an expert system modeling by constructing a knowledge-based system of the dive recovery for anticrash on the ground or sea during the task of fighter aircraft. In an IBM PC / XT computer, a prototype dive recovery expert system is constructed using mu LISP-86 programming language, and is interconnected to the SAM SUNG RM-501 robot arm to test and simulate this model. The knowledge base of this model is composed of the dive recovery charts and the V-N envelope charts of F-4 D Phantom fighter aircraft. It is shown that the prototype expert system woks well and the feasibility of practical realization is valid.

• Journal of Industrial Technology
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• v.14
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• pp.77-87
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• 1994

This research is an experimental work of investigating the behavior of soil nailing system under surcharges whereas most of them were concentrated on evaluating its capacity under selfweight of excavated ground. Model tests in laboratory were performed to investigate the ultimate bearing capacity of soil nailing system under surcharges in forms of strip loading. Tests were carried out to find parameters controlling its capacity such as length of nail, vertical and horizontal spacings between nails, inclination of nail installation, and loading position of surcharges. Failure mechanism of forming failure line due to surcharge to soil nailing system was also observed by using dyed sand and monitoring its behavior. From results of these test, effects of parameters was analyzed qualitatively. Thus, this experimental results could provide meaningful data to analyze and design this system later.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.601-607
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• 2002

Infiltration of rainfall causes railway embankment to be unstable and may result in failure. Basic relationship between the stability of railway embankment and rainfall introducing the partial saturation concept of ground are defined to analyze the stability of embankment by rainfall. A pressure plate test is also peformed to obtain soil-water characteristic curve of unsaturated soils. Based on this curve, the variables in the shear strength function and permeability function are also defined. These functions are used fur the numerical model for evaluation of railway embankments under rainfall. As comparing the model and case studies, the variation of shear strength, the degree of saturation and pore-water pressure for railway embankment during rainfall can be predicted and the safety factor of railway embankment can be expressed as the function of rainfall amount namely rainfall index. Therefore, the research on safety factor on railway embankment considering train speed and rainfall infiltration with the variation of rainfall intensity and rainfall duration was carried out in this paper.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.732-734
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• 2003

In the middle -resolution remote sensing, the Ground Sampled Distance(GSD) sensed and sampled by the detector is generally larger than the size of objects(or materials) of interest, in which case several objects are embedded in a single pixel and cannot be detected spatially. This study is intended to solve this problem of a hyperspectral data with high spectral resolution. We examined the detection algorithm, Linear Spectral Mixing Model, and also made a test on the Hyperion data. To find class Endmembers, we applied two methods, Spectral Library and Geometric Model, and compared them with each other.

• Geomechanics and Engineering
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• v.13 no.6
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• pp.963-975
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• 2017

Improvement of soft clay deposit by preloading with vertical drains is one of the most popular techniques followed worldwide. These drains accelerate the rate of consolidation by shortening the drainage path. Although the analytical and numerical solutions available are mostly based on equal strain hypothesis, the adoption of free strain analysis is more realistic because of the flexible nature of the imposed surcharge loading, especially for the embankment loading used for transport infrastructure. In this paper, a numerical model has been developed based on free strain hypothesis for understanding the behaviour of soft ground improvement by vertical drain with preloading. The unit cell analogy is used and the effect of smear has been incorporated. The model has been validated by comparing with available field test results and thereafter, a hypothetical case study is done using the available field data for soft clay deposit existing in the eastern part of Australia and important conclusions are drawn therefrom.

• Korean Journal of Remote Sensing
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• v.19 no.5
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• pp.341-349
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• 2003

The so-called B-method, a simplified surface energy budget, permits calculation of daily actual evapotranspiration (ET) using remotely sensed data, such as NOAA-AVHRR. Even if the use of satellite data allows estimation of the albedo and surface temperature, this model requires meteorological data measured at ground-level to obtain the other inputs. In addition, a difficulty may be occurred by the difference of temporal scales between the net radiation in daily scale and instantaneous measurement at midday of the surface and air temperatures because the data covered whole day are necessary to obtain accumulated daily net radiation. In order to solve these problems, this study attempted a modification of B-method through an extension of hourly ET value calculated using a complete instantaneous inputs. The estimation of the daily apparent ET from newly proposed system showed a root mean square error of 0.26 mm/day as compared the output obtained from the classical model. It is evident that this may offer more rapid estimation and reduced data volume.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.8
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• pp.691-701
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• 2017

The barbell squat is a fundamental physical exercise for strengthening the lower body and core muscles. It is an integral part of training and conditioning programs in sports, rehabilitation, and fitness. In this paper, we proposed a virtual test framework for squat exercises using a Smith machine to simulate joint torques and muscle forces, based on an integrated product-human model and motion synthesis algorithms. We built a muscular skeletal human model with boundary conditions modeling the interactions between the human body and a machine or the ground. To validate the model, EMG, external forces, and squat motions were captured through physical experiments by varying the foot position. A regression-based motion synthesis algorithm was developed based on the captured squat motions to generate a new motion for a given foot position. The proposed approach is expected to reduce the need for physical experiments in the development of training programs.

• Journal of the Korean GEO-environmental Society
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• v.12 no.8
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• pp.5-12
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• 2011

This study was performed to analyze the degree of rainfalls, the duration time of rainfalls, the inclination of slopes and other damage causes depending on the ground condition, when the landslide occurs by the rainfall. Based on that, a big and a small model soil box were compared to examine the features of landslides, which is ultimately for forecasting landslides. An artificial rainfall device was installed in the model box, and the large model box has a real-size slope in it. Also, various measures were fulfilled such as collapse forms, a pore pressure, an earth pressure and moisture contents in order to analyze the effect of the model box size on the landslide mechanism and to test the usability of a small model box as a material for landslide experiments.