• Geophysics and Geophysical Exploration
• /
• v.13 no.1
• /
• pp.24-30
• /
• 2010

This study utilises repeated numerical tests to understand the effects of variable near-surface conditions on time-lapse seismic surveys. The numerical tests were aimed at reproducing the significant scattering observed in field experiments conducted at the Naylor site in the Otway Basin for the purpose of $CO_2$ sequestration. In particular, the variation of elastic properties of both the top soil and the deeper rugose clay/limestone interface as a function of varying water saturation were investigated. Such tests simulate the measurements conducted in dry and wet seasons and to evaluate the contribution of these seasonal variations to seismic measurements in terms of non-repeatability. Full elastic pre-stack modelling experiments were carried out to quantify these effects and evaluate their individual contributions. The results show that the relatively simple scattering effects of the corrugated near-surface clay/limestone interface can have a profound effect on time-lapse surveys. The experiments also show that the changes in top soil saturation could potentially affect seismic signature even more than the corrugated deeper surface. Overall agreement between numerically predicted and in situ measured normalised root-mean-square (NRMS) differences between repeated (time-lapse) 2D seismic surveys warrant further investigation. Future field studies will include in situ measurements of the elastic properties of the weathered zone through the use of 'micro Vertical Seismic Profiling (VSP)' arrays and very dense refraction surveys. The results of this work may impact on other areas not associated with $CO_2$ sequestration, such as imaging oil production over areas where producing fields suffer from a karstic topography, such as in the Middle East and Australia.

• Journal of Periodontal and Implant Science
• /
• v.29 no.2
• /
• pp.415-433
• /
• 1999

Implant stability is the key to long-term successful outcome for osseointegrated implants. To evaluate the initial healing response of bone around HA-coated implants without primary bone contact. 21 HA-coated thread type implants(STERI-OSS?) were placed in the femurs of 5 mongrel dogs, about 1-year old. Implants, 8 mm in length and 3.8mm(experimental 1group), 5.0mm(experimental 2group) and 6.0mm(control group) in diameter, were inserted after 3 holes of 6.0mm in diameter and 10mm in depth were prepared in the surgical sites each dog. Implants were supported by only nonresorbable membrane($Teflon^{(R)}$), in order to prevent the ingrowth of upper soft tissue into the gap between bone and implant, and to maintain each implant to be positioned in the center of the drilled hole. 9 implants with different diameters were inserted in 3 dogs for histologic observation, and 12 implants were inserted in 2 dogs for mobility test and removal torque test. Fluorescent dyes were injected for the observation of new bone formation in order of $Terramycin^{(R)}$, Arizarin $Red^{(R)}$, and $Calcein^{(R)}$ at an interval of 2 weeks. 3 dogs were sacrificed for histologic observation at 4, 8, and 12-week after placement. Light microscopy and confocal laser scanning microscopy were used to qualitatively characterize the bone around HA-coated implant. 2 dogs were sacrificed for mobility test($Periotest^{(R)}$, Simens AG, Bensheim, Germany) and removal torque test($Autograph^{(R)}$ AGS-1000D series, Japan) at 8 and 12-week after placement The results were as follows: 1. Histologic observation showed that osseointegration occurred to both control and experimental groups as time lapse, but delayed bone healing was revealed in 3.8mm group (experimental 1group), compared to contrtol group and 5.0mm group (experimental 2group). 2. The mobility test showed that the experimental groups had no distinguishable movement during experimental periods of 8 and 12-week, and there was no difference in mobility depending on the gap between bone and implant, and time lapse. 3. The removal torque forces were increased depended on the gaps decreasing between bone and implant, and time lapse. The results suggest that HA-coated implant without primary bone contact, based on guided bone regeneration could obtain its stability in all experimental groups as time lapse, but bone healing was delayed in experimental group of 3.8mm. And the results suggested that studies on correlationship between mobility test and removal torque test for implant stability would be necessary.

• Korean Security Journal
• /
• no.31
• /
• pp.7-24
• /
• 2012

In this study a practical guarding work is carried out for 180 minutes as the same as the actual guarding work that is done by nine students of the department of security services in K University in order to investigate changes in circadian rhythms during long hour guarding in bodyguards at practical sites. In the results of the tests of the heart rate variation and autonomic nervous system with the interval of 30 minutes using HRV (Heart rate variability), there are no significant differences in HRV and SDNN and that leads to maintain it stably during the guarding work for 180 minutes. In the case of TP which reflects the overall activity level in the autonomic nervous system, it shows a high significant difference (p<.05) at 90 and 120 minutes compared to that of normal states. Also, it shows a significant decrease in the level after a lapse of 120 minutes and that shows a decrease in the activity of the autonomic nervous system for the guarding work more than 120 minutes. Although differences in VLF, LF, and HF are not significant levels, these are influenced on the change in TP. The LH/HF ratio that represents the balance between the sympathetic nerve and the parasympathetic nerve shows a significant high level (p<.05) after a lapse of 30 minutes. Thus, it is considered that the concentration of the guarding work after a lapse of 120 minutes is decreased and there are some tensions and excitations after a lapse of 30 minutes since the beginning of the guarding work.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.3 no.2
• /
• pp.96-104
• /
• 2001

Usage of ecosystem models has been extended to landscape scales for understanding the effects of environmental factors on natural and agro-ecosystems and for serving as their management decision tools. Accurate prediction of spatial variation in daily temperature is required for most ecosystem models to be applied to landscape scales. There are relatively few empirical evaluations of landscape-scale temperature prediction techniques in mountainous terrain such as Korean Peninsula. We derived a periodic function of seasonal lapse rate fluctuation from analysis of elevation effects on daily temperatures. Observed daily maximum and minimum temperature data at 63 standard stations in 1999 were regressed to the latitude, longitude, distance from the nearest coastline and altitude of the stations, and the optimum models with $r^2$ of 0.65 and above were selected. Partial regression coefficients for the altitude variable were plotted against day of year, and a numerical formula was determined for simulating the seasonal trend of daily lapse rate, i.e., partial regression coefficients. The formula in conjunction with an inverse distance weighted interpolation scheme was applied to predict daily temperatures at 267 sites, where observation data are available, on randomly selected dates for winter, spring and summer in 2000. The estimation errors were smaller and more consistent than the inverse distance weighting plus mean annual lapse rate scheme. We conclude that this method is simple and accurate enough to be used as an operational temperature interpolation scheme at landscape scale in Korea and should be applicable to elsewhere.

• Geophysics and Geophysical Exploration
• /
• v.17 no.2
• /
• pp.104-113
• /
• 2014

Electric resistivity monitoring was applied to evaluate the soft ground in reclaimed land in order to figure out the applicability of physical prospecting. For this, electrical resistivity monitoring data were acquired for total three months and analyzed those data with independent inversion, time-lapse inversion, and 4D inversion methods. The result was compared for various inversion methods so as to figure out what showed the soft soil most properly. Moreover, drilling and CPT(Cone Penetration Test) data were also used in order to find out if each of those inversion methods could distinguish either bed rock or the soft soil clearly. And according to the result, time-lapse inversion showed less inversion artifacts than independent inversion, so it could indicate the soft soil better. If data gained for a longer period than three months are used, 4D inversion has been found to be a more efficient analysis method than the time-lapse inversion method. Electrical resistivity monitoring on the soft soil has been found to be a useful method that can analyze the spatio-temporal electric state of the ground serially.

• Korean Journal of Culture and Social Issue
• /
• v.15 no.4
• /
• pp.487-505
• /
• 2009

We focused on the missing confirmation domain of the hasteful behavior. We tried to identify the variety of hasteful behavior and the effects of missing confirmation behavior domain of the hasteful behavior on driving behaviors. 388 drivers responded to Hasteful Behavior Questionnaire, Driver Behavior Questionnaire(DBQ), and Driving Experience Questions. Data which have missing values among them were removed, 374 data were analyzed. As a result of factor analysis, hasteful behavior consist of time pressure, uncomfortableness, isolation, boring condition, and expecting rewards, and the DBQ consist of violation, error, and lapse. The components of hasteful behavior was divided into the missing confirmation behavior and the need for achievement domain by the second factor analysis and difference verification of coefficient of correlation. The missing confirmation behavior domain of hasteful behavior had significant influence on error and lapse. The isolation of the missing confirmation behavior domain had a negative effect, and the uncomfortableness of the missing confirmation domain had a positive effect on violation. The time pressure had a negative effect, and the isolation and the uncomfortableness had a positive effect on error and lapse.

• Korean Journal of Culture and Social Issue
• /
• v.12 no.1
• /
• pp.55-79
• /
• 2006

This study is interested in aberrant driver behaviour. The aim of this study is to investigate the effect of error and lapse on driving behaviour of elderly drivers. In order to estimate the errors and lapses, 'Driver Behaviour Questionnaire(DBQ) was used and tested with 883 drivers. Among them 175 of young drivers(younger than 25) and 150 of elderly drivers(older than 65) answered their driving patterns; driving history, annual mileage, the frequency of committing traffic violation, and experience of accident within 5 years. Elderly driver's data were collected by face to face interview. The factors of aberrant driver behaviour were analyzed and the DBQ score was compared by the age. The aberrant driver behaviour was consisted of 3 factors; violations, errors and lapses. Elderly driver's DBQ score was lower than young driver's. Elderly and young drivers showed longer driving history. were in low DBQ score group. Elderly drivers had high error score and young drivers had high violation score. Young driver's aberrant driving behaviour was associated with annual mileage, the frequency of committing traffic violation. Elderly driver's aberrant driving behaviour was associated with annual mileage, experience of accident. Specially elderly drivers, whose violation, error, lapse score was high answered more committing experience of accident within 5 years.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2011.10a
• /
• pp.189-192
• /
• 2011

• Journal of Korean Medical classics
• /
• v.19 no.4
• /
• pp.169-181
• /
• 2006

The Samyang-Sameum(三陽三陰) is the movement form peculiar to the cosmic dual forces. Since Byunggi(病氣) along with the Gyungkki(經氣), The Samyang-Sameum(三陽三陰) is the standard for a diagnosis of a disease's outbreak and change. Anyone of The Samyang-Sameum(三陽三陰) can cause a disease in a Gyungkki(經氣) because each and every human being has different Gyungkki(經氣). And, a disease may outbreak by anyone of Wind-Cold-Warmth-Heat(風寒溫熱). Guiding principles of the six Meridians(六經提綱) is set to diagnose which one of the Gyungkki(經氣) causes a disease. Sanghallon(傷寒論) shows several measures to diagnose the lapse of a disease at the beginning stage of external affection(外感) by Wind-Cold(風寒). It is most serious when the Jeongyung(傳經) symptom appears within 6 to 7 days after a disease outbreak since it indicates the exhaustion of true Eum(眞陰). It means the lapse of a disease that formation of dry stool(燥尸) by fast Jeonsok(轉屬) to Yangmyeong(陽明) after a Taeyang(太陽) is diseased. It also means that a position of disease is worsening by a sticking phase of disease when Yipeum(入陰) symptom after anyone of Samyang-Sameum(三陽三陰) is diseased.

• Geotechnical Engineering
• /
• v.11 no.3
• /
• pp.5-16
• /
• 1995

In this paper, two leaching tests(batch test & column test) were carried out to estimate the detrimental effects of coal ash leachates. The variation of constituents and concentration of coal ash leachate with the lapse of leachins time was analysed through the column tests. From the test results, it was found coal tach can be classified as a general waste, and all other items except pH of coal ash leachate are satisfied the concentration requirements for the drinking water. It was also found the concentration of coal ash rapidly decrease with the lapse of the leaching time and become the insignificant value after an elapsed time.