• Korean Journal of Cognitive Science
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• v.17 no.1
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• pp.15-27
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• 2006

The effects of the number of Hangul syllable, the nunber/location of batchim in a Hangul word, and compound/noncompound Hangul word on memory span were examined. The results were that (1) the more syllables a word had, the lower us memory span was, (2) the more batchims a two-syllable word had, the lower its memory span was (Korean batchim effect on memory span), (3) noncompound word had higher memory span than compound word. The reading speed of above mentioned words was measured and the results were that (1) the more syllables a word had, the slower its reading speed was, (2) but the reading speed of a two-syllable word was forest when it had a batchim on second syllable than when it had no batchim or had a batchim on first syllable or batchims on both syllables (Korean ending batchim effect on reading speed), (3) noncompound word was read faster thu compound word. Korean ending batchim effect on reading speed was not compatible with the explanation by articulatory loop bur compatible with the explanation by visual cache where the orthographic information was represented. The results suggest that memory span was influenced nor only by phonological information but also by orthographic information.

• Journal of Preventive Medicine and Public Health
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• v.24 no.4 s.36
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• pp.507-515
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• 1991

One, two, six and ten week old Sprague-Dawley rats were exposed to carbon monoxide at 3,700 ppm for 30 minutes, and carboxyhemoglobin was measured immediateley. 5, 30, 60, 90, 120 minutes after the exposure. In each time after the exposure, the means of the carboxyhemoglobin levels were compared among the week age groups. The regression analysis was done using the natural logarithm of the carboxyhemoglobin concentration as a dependent variable and the time after the exposure as an independent vaiable. From the regression equation, the half lives of the carboxyhemoglobin were calculated. The one week old rats showed significantly higher carboxyhemoglobin level than other week age rats in the entire time after the exposure. The corrected carboxyhemoglobin concentration calculated by subtracting the normal carboxyhemoglobin level from the measured carboxyhemoglobin at each age group, showed no uniform differences.

• Magazine of the Korea Concrete Institute
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• v.10 no.4
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• pp.135-143
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• 1998

The wheel load distribution width for lane load is not specified in current Korea bridge design code(KD code), not like in current AASHTO and AASHTO LRFD specifications which specity it as twice of wheel load distribution width for wheel load. In this study, the wheel load distribution width in continuous reinforced concrete slab bridge is investigated. The major variables affecting the wheel load distribution of a reinforced concrete continuous slab bridge are the span length, bridge width, existence edge beam and boundary condition. From a series of comprehensive parametric study on each variable, the formula for wheel load distribution in continuous reinforced concrete slab bridge is proposed from the nonlinear regression analysis of finite element analysis results. The proposed formulas can be used efficiently in the accurate design of continuous reinforced concrete slab bridges.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.4
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• pp.206-212
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• 2004

The numerical analysis on the wave screening performance of the submerged breakwater with various crown widths is presented. The fluid motion is considered as linearized two dimensional potential flow and the finite element method is used to analyze the wave screening performance of the submerged breakwater. It is found that single-submerged breakwater with large crown width shows the most effective wave screening performance and single-submerged breakwater with small crown width also shows fairly good wave screening performance but its effectiveness is less than that of single-submerged breakwater with large crown width. However, double- or triple-submerged breakwater with small crown width shows more effective wave screening performance than that of single- or double-submerged breakwater with large crown width. It is expected that the submerged breakwater with small crown width is economical because it reduces the size of structure.

• Progress in Medical Physics
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• v.9 no.4
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• pp.217-225
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• 1998

In this paper, the analysis of the relation between noise induced hearing loss and noise exposure is described for the A-weighted noise levels and exposure duration. The hearing loss and sensitivity threshold shift is investigated by changing the various parameters such as the effects of aging and noise exposure. Total hearing loss is proportional to a function of exposure level based upon the integral of pressure with time. If the noise exposure term is large so that the presbycusis may be neglected, the hearing loss due to aging and noise exposure becomes the noise induced hearing loss. It is shown that exposure to excessive noise can cause temporary loss of hearing that may become permanent if the exposure is prolonged or intense. An audiogram taken from a person suffering from noise induced hearing loss will usually show the greatest loss of hearing sensitivity in the 4kHz region, which is typically the region most sensitive to damage resulting from many types of industrial noise.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.140-143
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• 2011

산불의 확산형태 중 지표화 확산을 방지하기 위해 대표적인 진화방법으로는 방화선을 구축하는 것이다. 지표화는 산림의 연료중 낙엽층, 잔가지 등 지표면의 연료층이 열분해되면서 확산되기 때문에 방화선 구축을 통해 연료층을 제거하면 지표화 확산을 저지할 수 있다. 하지만 방화선 구축 폭에 따라 산불확산 방지 효과가 크게 달라질 수 있으므로 적정한 방화선 구축 폭을 설정하여야 한다. 본 연구에서는 적정 방화선 구축 폭을 살펴보기 위해 풍동시험장치를 이용하여 풍속 0, 1, 2, 3m/s조건에서 지표화 화염으로부터 이격 거리에 따른 온도측정과 함께 방화선 구축 폭에 따른 확산가능 여부를 평가하였다. 50cm 폭의 소나무 낙엽에 대한 풍속별 지표화 방화선 구축 실험결과, 풍속 3m/s에서 화염으로부터 소나무 낙엽의 착화온도인 $311^{\circ}C$에 도달하는 거리가 약 0.65m로 나타났고 풍속이 낮을수록 착화온도 도달거리가 줄어드는 것을 알 수 있다. 실제 0.6m 방화선 구축의 경우, 화염이 계속 확산되었고 0.65m 이상의 방화선 구축시에는 화염확산이 이루어지지 않았다. 따라서 향후, 수치해석을 이용한 열유속 평가 결과와 함께 본 연구의 실험결과와 비교평가 함으로써 지표화 산불확산 방지를 위한 적정 방화선 구축 폭 산정을 평가하고자 한다.

• Korean Journal of Optics and Photonics
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• v.6 no.4
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• pp.345-351
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• 1995

We have studied experimentally the propagation characteristics of fundamental dark spatial solitons on finite-width backgrounds and conpared with the result of numerical simulations. It was verified experimentally that the width of dark solitons decreased but that of background increased as the beam intensity increased. The refractive index change obtained from soliton constant, which is for infinite-width background, was smaller than that from Z-scan method. Numerical simulations of fundamental dark solitons on a finite-width backgrounds showed that the peak intensity of background, the width of dark soliton and the soliton constant varied with the propagation length. If the change of soliton constant on finite-width backgrounds was considered, the refractive index change was in good agreement with that from Z-scan method. ethod.

• Journal of Korea Water Resources Association
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• v.34 no.2
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• pp.141-154
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• 2001

An experimental study was performed to investigate the effects of levee crest width and the slope steepness on levee break due to overtopping flow. The phenomenon of bank failure can be described in 4 stages. In this study, the magnitudes of breach width, breach depth peak discharge, and scouring shape at the break site were measured, and the result shows that peak discharge will be reduced and breach duration extended by widening the crown width and lessening the levee slope steepness. The breach width was narrower and the breach depth deeper, as the levee crest width become wider or the slope steeper. And, the bed scour depth was deeper and steeper, as the levee crest crest width become narrower or the slope milder.

• Journal of Preventive Medicine and Public Health
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• v.30 no.1 s.56
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• pp.61-67
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• 1997

This study was performed to evaluate the effects on hearing of video tape manufacturing workers exposed to organic solvents. The experimental groups included solvents exposed group 51 and unexposed group 57 workers. All workers was examined air and bone conduction sensitivity by pure tone audiometer. The mean age of solvents exposed group was 34.1 and nonexposed group was 35.8. The mean duration of solvents exposed group was 7.3years. High frequency hearing loss prevalence of both groups was 23.5% in the group exposed to organic solvents and 17.5% in nonexposed group. There is no statistical significants in the prevalence of high frequency hearing loss. According to comparison of mean auditory threshold value by frequencies, on the air conduction test, right was statistically significant in the 250, 500, 1000, 2000, 4000Hz, except 8000Hz. Left 250, 500, 1000Hz was statistically significant. On the bone conduction test, left 250, both 500, 1000, 2000, 4000Hz, except right 250Hz, was statistically significant difference. Generally, auditory sensitivity threshold of the exposed group was higher than the nonexposed group.

• International Journal of Highway Engineering
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• v.4 no.2 s.12
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• pp.33-42
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• 2002

The cracks in the pavements result from drying shrinkage, temperature change, repeated traffic loadings and so on. The reduction of soil support, spatting and many local failures are caused by water and incompressible foreign materials infiltrated into the cracks. In order to reduce this kind of problems the crack width must be controlled and managed by the accurate measurement. The current method is a visual survey using a microscope, which requires traffic blocking. The purpose of this study is to find the best condition to measure accurate crack width using automated pavement condition survey equipment running at the similar speed as other vehicles. In this study pavement surfaces are filmed on an enlarged scale by the camera with a zoom lens, and then the proper focal distance is determined according to the crack width through a pilot survey. The conditions for measurement of the accurate crack width using the image processing technique are suggested by comparing crack widths surveyed using a microscope in the field with those computed by various factors in the image processing program, STADI-2. In conclusion, the camera with a focal distance of 75m could detect crack range of 0.5mm$\sim$1.2mm In width with an accuracy of 80% for CRCP. The camera with a focal distance of 12.5mm could detect crack range of 1.8mm$\sim$3.3mm in width with an accuracy of 90% for asphalt pavement.