• International Journal of Highway Engineering
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• v.10 no.4
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• pp.161-170
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• 2008

This study deals with the accident models by vehicle type. The goal is to develop the accident models by vehicle type using the data of 143 4-legged signalized intersections in Cheongju. In pursuing the above, this study gives the particular attentions to explaining the relationships between the values of EPDO(equivalent property damage only) and the traffic and geometric elements. The main results analyzed are the followings. First, 6 negative binomial models are developed, which are all significant at the 90% confidence level. Second, the values of ${\rho}^2$ by vehicle type are 0.14307(auto), 0.35556(large van), 0.21684(small van), 0.205152(motocycle), 0.32338(light-duty truck) and 0.29046(heavy-duty truck), that are all analyzed to be statistically significant. Finally, the common variable included in all models is ADT(average daily traffic), and the specific variable(SV) of auto is analyzed to be the sum of lane width of main road, SV of large van is the average yellow time, and SV of small van is the difference in the number of lane between main and minor road.

• The Journal of Fisheries Business Administration
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• v.31 no.2
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• pp.133-153
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• 2000

During the last several decades, Korea has been regarded as one of the fastest growing economies in the world. However, the small size of national land has not met the vigorous demand for land necessary to develop economic infra-structures such as large-scale harbors airports and highways. In order to satisfy the growing demand for land, the Korean government and industry have implemented the national land development programs to reclaim land from the sea fur the several decades. It is certain that these land development programs have resulted in a lot of property disputes between fishermen and public project administrators. This paper is to develop a quantitative model to estimate compensation for damages or restriction of charted fisheries resulting from large-scale public projects. In this paper, the compensation model is derived by using cost-volume-profit analysis framework because the compensation for charted fisheries basically depends on the factors such as the costs, production volume, profit of charted fisheries damaged or restricted by public projects. The model shows that the compensation for damages or restriction of charted fisheries is determined by the average annual profit, damage duration period, and the degree of fishery damages. In addition, the degree of fishery damages measured by the ratio of lost profit to annual average profit turns out to be determined by the following factors: annul profit, unit variable cost, decrease in production volume, the rate of increase in variable cost, and a change in fixed cost. Furthermore, this parer discusses the nam issues related to practices and regulation of the compensation for fishery damages in the current Fishery Act of Korea and suggests some appraisal methods which will be able to lead to theoretically correct and fair compensation for fisheries damages resulting from large-scale public projects.

• Earthquakes and Structures
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• v.10 no.2
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• pp.329-350
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• 2016

A parametric study was conducted to investigate the seismic deformation demands in terms of drift ratio, plastic base rotation and compression strain on rectangular wall members in frame-wall systems. The wall index defined as ratio of total wall area to the floor plan area was kept as variable in frame-wall models and its relation with the seismic demand at the base of the wall was investigated. The wall indexes of analyzed models are in the range of 0.2-2%. 4, 8 and 12-story frame-wall models were created. The seismic behavior of frame-wall models were calculated using nonlinear time-history analysis and design spectrum matched ground motion set. Analyses results revealed that the increased wall index led to significant reduction in the top and inter-story displacement demands especially for 4-story models. The calculated average inter-story drift decreased from 1.5% to 0.5% for 4-story models. The average drift ratio in 8- and 12-story models has changed from approximately 1.5% to 0.75%. As the wall index increases, the dispersion in the calculated drifts due to ground motion variability decreased considerably. This is mainly due to increase in the lateral stiffness of models that leads their fundamental period of vibration to fall into zone of the response spectra that has smaller dispersion for scaled ground motion data set. When walls were assessed according to plastic rotation limits defined in ASCE/SEI 41, it was seen that the walls in frame-wall systems with low wall index in the range of 0.2-0.6% could seldom survive the design earthquake without major damage. Concrete compressive strains calculated in all frame-wall structures were much higher than the limit allowed for design, ${\varepsilon}_c$=0.0035, so confinement is required at the boundaries. For rectangular walls above the wall index value of 1.0% nearly all walls assure at least life safety (LS) performance criteria. It is proposed that in the design of dual systems where frames and walls are connected by link and transverse beams, the minimum value of wall index should be greater than 0.6%, in order to prevent excessive damage to wall members.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.2
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• pp.19-27
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• 2008

Objective : The side effect of prolonged use of topical corticosteroids to skin is well-known. Moreover, resent studies have shown that prolonged use of systemic corticosteroids also negatively impacts skin barrier function. Corticosteroids have a major role in the practical management of many variable conditions. So, it is important to find the drug or the method which could protect the skin from the damage caused by corticosteroids. At former study, we investigated that Insamyangyoung-tang has some effect on skin barrier function of DNCB induced contact dermatitis hairless mice. So, this study was performed to research the effect of Insamyangyoung-tang on the TEWL with high dose steroid injected hairless mice. Method : Hairless mice were divided into 4 groups ; Control group, Group A, Group B and Group C. All groups were injected triamcinolone O.4mg for 10 times. Control group was medicated distilled water during the experimental period. Group A was medicated distilled water for 5 days before the $1^{st}$ injection day, and then medicated Insamyangyoung-tang extract during the experimental period. Group B was medicated Insamyangyoung-tang extract for 5 days before the $1^{st}$ injection day, and then medicated distilled water during the experimental period. Group C was medicated Insamyangyoung-tang extract for 5 days before the $1^{st}$ injection day, and then medicated Insamyangyoung-tang extract during the experimental period. TEWL of each group was measured for 5 times. After the $10^{th}$ injection, the tissue sample was made and the damage of epithelial cell was examined. Statistical significance was set at p<0.05 by using non parametric methods and repeated-anova.. Results : Group C showed significant effect on TEWL change of hairless mice evoked by triamcinolone injection. Group A and Group B also showed some effect, but there was no statistical significance.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.151-158
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• 2009

This study deals with the rear-end collisions in the rural aiea. The objectives of this study are 1) to analyze the characteristics of rear-end accidents of signalized intersections, and 2) to develop the accident models for Cheongju-Cheongwon. In pursing the above, this study gives the particular attentions to comparing the characters of urban and rural area. In this study, the dependent variables are the number of accidents and value of EPDO(equivalent property damage only), and independent variables are the traffic volumes and geometric elements. The main results analyzed are the followings. First, the statistical analyses show that the Poisson accident model using the number of accident as a dependant variable are statistically significant and the negative binomial accident model using the value of EPDO are statistically significant. Second, the independent variables of Poisson model are analyzed to be the ratio of high-occupancy vehicles, total traffic volume and the sum of exit/entry, and those of negative binomial regression are the main road width, total traffic volume and the ratio of high-occupancy vehicles. Finally, the specific independent variables to the rural area are the main road width, the ratio of high occupancy vehicle, and the sum exit/entry.

• Journal of Biosystems Engineering
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• v.41 no.1
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• pp.12-20
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• 2016

Purpose: Pepper prices have risen continuously because of a decrease in cultivation area; therefore, mechanical harvesting systems for peppers should be developed to reduce cost, time, and labor during harvest. In this study, a screw type picking head for a self-propelled pepper harvester was developed, and the optimal working conditions were evaluated considering helix types, winding directions of helix, and rotational speeds of the helix. Methods: The screw type was selected for the picking head after analyzing previous studies, and the device consisted of helices and a feed chain mechanism for conveying pepper branches. A double helix and a triple helix were manufactured, and rotational speeds of 200, 300, and 400 rpm were tested. The device was controlled by a variable speed (VS) motor and an inverter. Both the forward and reverse directions were tested for the winding and rotating directions of the helix. An experiment crop (cultivar: Longgreenmat) was cultivated in a plastic greenhouse. The test results were analyzed using the SAS program with ANOVA to examine the relationship between each factor and the performance of the picking head. Results: The results of the double and triple helix tests in the reverse direction showed gross harvest efficiency levels of 60-95%, mechanical damage rates of 8-20%, and net marketable portion rates of 50-80%. The dividing ratio was highest at a rotational speed of 400 rpm. Gross harvest efficiency was influenced by the types of helix and rotational speed. Net marketable portion was influenced by rotational speed but not influenced by the type of helix. Mechanical damage was not influenced by the type of helix or rotational speed. Conclusions: Best gross harvest efficiency was obtained at a rotational speed of 400 rpm; however, operating the device at that speed resulted in vibration, which should be reduced.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.199-209
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• 2011

In the study of traffic safety, the analysis on factors affecting crash severity and the understanding about their relationship is important to be planning and execute to improve safety of road and traffic facilities. The purpose of this study is to develop a hierarchical binomial logistic model to identify the significant factors affecting fatal injuries and vehicle damages of traffic crashes on freeway. Two models on death and total vehicle damage are developed. The hierarchical structure of response variable is composed of two level, crash-occupant and crash-vehicle. As a result, we have gotten the crash-level random effect from these hierarchical structure as well as the fixed effect of covariates, namely odds ratio. The crash on the main line and in-out section have greater damage than other facilities. Injuries and vehicle damages are severe in case of traffic violations, centerline invasion and speeding. Also, collision crash and fire occurrence is more severe damaged than other crash types. The surrounding environment of surface conditions by climate and visibility conditions by day and night is a significant factor on crash occurrence. On the orher hand, the geometric condition of road isn't.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.269-272
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• 2008

This paper reports on the cracking mitigation and flexural behavior experimentally observed in concrete prisms layered with strain-hardening cement composites (SHCCs) which is micro-mechanically designed cement composite and exhibits pseudo tensile strain-hardening behavior accompanied by multiple cracking while using a moderate amount of fiber, typically less than 2 percent in term of fiber volume fraction. In this study, SHCC is reinforced with 1.3 percent polyvinyl alcohol (PVA) and 0.20 percent polyethylene (PE) in volume fraction. Tests were conducted using $100{\times}100{\times}400mm$ long prisms supported over a simply supported span of 350mm. The four point load was applied using MTS servo control machine. The thickness patched with SHCC is the main variable for this study. Experimental study shows that when subject to monotonic flexural loading, the SHCC layered repair system showed 2.7 - 4.2 times increased load carrying capacity, and mitigated cracking damage of concrete beams layered with SHCC compared with plain concrete beams.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.180-185
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• 2001

In the life assessment for plant structural component, the research on deterioration of toughness and material properties occurred in weldments has been considered as very important problems. In general, the microstructures composed in weldments are hugely classified with weld metal(W.M), fusion line(F.L), heat affected zone(HAZ), and base metal(B.M). It has been reported that the creep characteristics on weldments having variable microstructures could be unpredictably changed. Furthermore, it is also known that HAZ adjacent to F.L exhibits the decreased creep strength compared to those in base or weld metals, and promotes the occurrence of Type III and Type IV cracking due to the growth of grains and the coarsening carbides precipitated in ferritic matrix by welding and PWHT processes. However, the lots of works reported up to date on creep damage in power plant components have been mostly conducted on B.M and the creep properties on a localized microstructures in weldments have not as yet been throughly investigated. In this paper, for various microstructures such as coarse grain HAZ(CGHAZ), W.M and B.M in X20CrMoV121 steel weldment, the small punch-creep(SP-Creep) test using miniaturized specimen(t=0.5mm, 0.25mm) is performed to investigate a possibility for creep characteristics evaluation.

• Journal of the Korean Society of Radiology
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• v.14 no.6
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• pp.781-790
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• 2020

Tract-Based Spatial Statics (TBSS) after obtaining the image by examining a diffusion tensor image that can determine the presence or absence of damage to the cerebral white matter and gray matter for middle-aged men aged 30 to 50 with the starting age of drinking as a variable. As a result of measuring and analyzing the FA (fractional anisotropy) value of the brain gray matter region to the hippocampal region nerve fibers, the lower the alcohol start age in all regions, the lower the anisotropy measurement value, but the FA value was statistically significant. The study results indicated by the FA results measured in this study are that the earlier the drinking start age, the more severe the morphological changes in all neurological and anatomical brain regions in the hippocampal region of the brain gray matter and seriously affect the nerve fiber tissue. It can be said to harm and damage nerve fibers and affect functional morphological variations associated with alcohol.