• Journal of the Korean GEO-environmental Society
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• v.17 no.12
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• pp.45-54
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• 2016

In this study, the construction method of new underground continuos impervious wall that the bentonite slurry keeps the stability of excavated trench and the mixture of cement and bentonite plays a role as a constituent of impervious wall in the trench. The merit of homogeneity of the method so called as a cement-bentonite slurry wall enables to accurately make an estimation of hydraulic conductivity of the walls compared with that by other general grouting methods and to verify their waterproof efficiency without difficulty at the design stage. The use of cement-bentonite slurry walls for the containment of groundwater flow has also proven a cost-effective impervious wall technology by employing the simple combination of construction equipments and easy and fast construction procedures. The engineering characteristics of cement-bentonite impervious wall obtained by carrying out the laboratory experiments under various conditions. This study reveals the effect of variation of constituent materials and their mixing methods (Water-Cement-Bentonite) on the engineering characteristics of a composition. Also, this study makes some recommendations on the optimum mixing ratio and mixing sequence for the best quality at the site. That is the most important factors to estimate the construction cost and design of the technique. The comparison is lastly made to evaluate the effect of ordinary Portland and blast furnace slag cement as a bonding material on the behavior of impervious walls.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.1
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• pp.21-28
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• 2017

The steel-plate concrete(SC) is used in a form of module assembly construction in the outer wall of nuclear-power plant and LNG containment. Since the steel-plate concrete modules are generally manufactured from the plant, the weight of SC has significantly effect on the total construction cost in the aspect of shipment. Therefore, the use of lightweight aggregates concrete(LWAC), which fill the inside of SC module can be a solution. However, the amount of used lightweight aggregates(LWA) is limited in the use of current concrete mixing process due to the concrete quality problems and it also determines the allowable minimum density of LWAC. In this research, the preplaced casting method is applied because of increasing the volume fraction of LWA significantly, which results from the producing process of pre-packing the LWA in the formwork and filling the interstitial voids between LWA using cement paste grout. The density and compressive strength of selected preplaced LWAC were $1,600kg/m^3$ and 30MPa and it was applied for the mock-up specimens of SC panel. It was used for the 3-point bending test for evaluating its structural performance. The results show that the preplaced LWAC can reduce the density of concrete with the adequate mechanical and structural performance.

• Journal of Preventive Medicine and Public Health
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• v.28 no.1 s.49
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• pp.207-223
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• 1995

A new medical delivery system which regulated outpatient department(OPD) use from tertiary care hospitals was adopted in 1989. Under the new system, patients using tertiary care hospital OPD without referral slip from clinics or hospitals could not get any insurance benefit for the services received from the tertiary care hospital. This study was conducted to evaluate the Patient Referral System(PRS) with respect to health care expenditures and utilization. Two data sets were used in this study. One was monthly data set(from January 1986 to December 1992) from the Annual Report of Korea Medical Insurance Corporation(KMIC). The other was monthly joint data set composed of personal data of which 10% were selected randomly with their utilization data of KMIC from January 1988 to December 1992. The data were analyzed by time-series intervention model of SAS-ETS. The results of this study were as follows: 1. There was no statistically significant changes in per capita expenditures following PRS. 2. Utilization episodes per capita was increased statistically significantly after implementation of PRS. The use of clinics and hospitals increased significantly, whereas in tertiary care hospitals the use decreased significantly immediately after implementation of PRS and increased afterwards. 3. Follow-up visits per episode were decreased statistically significantly after implementation of PRS. The decrease of follow-up visits per episode were remarkable in clinics and hospitals, whereas in tertiary care hospitals it was increased significantly after implementation of PRS. 4. There was no statistically significant changes in prescribing days per episode following PRS. Futhermore, clinics and hospitals showed a statistically significant decrease in prescribing days per episode, whereas in tertiary care hospital it showed statistically significant increase after implementation of PRS. 5. Except high income class, the use of tertiary care hospitals showed statistically significant decrease after implementation of PRS. The degree of decrease in the use of tertiary care hospitals was inversely proportional to income. These results suggest that the PRS policy was not efficient because per capita expenditures did not decrease, and was not effective because utilization episodes per capita, follow-up visits per episode. and prescribing days per episode were not predictable and failed to show proper utilization. It was somewhat positive that utilization episodes per capita were decreased temporarily in tertiary care hospitals. And PRS policy was not appropriate because utilization episodes per capita was different among income groups. In conclusion, the PRS should be revised for initial goal attainment of cost containment and proper health care utilization.

• Health Policy and Management
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• v.4 no.1
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• pp.49-76
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• 1994

Small area variations in health care utilization have long been studied as an important issue related to boto cost containment and quality assurance. This study was conducted to investigate if variations in hospital services across small geographic areas in Korea existed. The claims data of the fiscal year 1992 obtained from the regional health insurance societies were used for the study. Main findings of the research can be summarized as follows : 1. Extremal Quotients(EQ) of hospital expenditure per capita and hospital days per capita varied among diagnosis types. The EQ ranged from 2.05(cataract) to 41.67(pneumonia) in hospital expenditure per capita and from 1.86(cataract) to 45.89(pneumonia) in hospital days per capita. The diagnosis groups which showed high variation were pneumonia, cephalo-pelvic disproportion, gastritis and duodenitis, fracture of rib, and acute bronchitis. Those which showed low variation were acute appendicitis and cataract. 2. The EQ level of admission rate was different in terms of diagnosis types, ranging from 2.57(catarct) to 44.45(pneumonia). The variations were high in medical disorders such as pneumonia, oephalo-pelvic disproportion, gastritis and duodenitis and acute bronchitis, while relatively low in surgical conditions such as acute appendicitis and cataract. 3. As an indicator of service intensity, the EQ of expenditure per admission ranged from 1.67(acute appendicitis) to 31.27(essential hypertension). The diagnoses which had high variation were essential hypertension, gastric ulcer, whereas those which had low variation were cephalopelvic disproportion and acute appendicitis. With regard to hospital days per admission, the EQ ranged from 1.55(acute appendicitis) to 28.13(gastric ulcer) by diagnosis types. The diagnosis groups with showed high variation were gastric ulcer, essential hypertension, and acute bronchitis, whereas those with low variation were cephalo-pelvic disproportion, intervertebral disc disorders, and acute appendicitis. Both the expenditure and hospital days per admission showed lewwer variations than the expenditure per capita, hospital days per capita and admission rate. 4. Comparing patterns of variation in utilization indices, diagnoses such as essential hypertension, gastric ulcer, fracture of rib showed higher variations in expenditure per admission than in admission rates, whereas diagnoses such as pneumonia, cephalo-pelvic disproportion and gastric ulcer showed higher variations in admission rate than expenditure per admission. These findings suggest that wide variations existed in several diagnoses groups across small areas in Korea. Further research should be performed to investigate factors related to small area variations including provider behavior.

• Journal of Preventive Medicine and Public Health
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• v.30 no.2 s.57
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• pp.437-461
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• 1997

Because of a significant improvement in the economic situation and development of scientific techniques in Korea during the last 30 years, the life expectancy of the Korean people has lengthened considerably and as a result, the number of the elderly has markedly increased. Such an increase of the number of aged population brought about many social, economic, and medical problems which were never seriously considered before. This study was conducted to assess the trend of medical care utilization and medical expenditure of the elderly. The data of each patient in the study were taken from computer database maintained for administrative purpose by the Korea Medical Insurance Corporation. The study population was 132,670 who were 60 years old or more and registered in Korean Medical Insurance Corporation from 1989 to 1993. The study subjects were predominantly female(56.3%) and 10,000-20,000 Won premium group(50.6%). The following are summaries of findings : The total increase of the number of inpatient cases was 40.5% from 1989 through 1993. The average annual increase was 3.7% in inpatient medical expenditures per case, 4.4% in inpatient medical expenditures per day and 0.08% in length of stay per case from 1989 through 1993. Cataract was the most prevalent disease of 10 leading frequent diseases in all ages from 1989 through 1993. The case mix in 1993 compared to 1989 revealed that cataract and ischemic cerebral disease were increased whereas essential hypertension and pulmonary tuberculosis were decreased . The average annual increase of medical expenditures was 3.8% in general hospitals, 6.3% in hospitals and 2.4% in clinics. From 1989 through 1993, medical expenditures used by high-cost patients accounted for about 14% to 20% of all expenditures for inpatient care, while they represented less than 2.5% of the elderly population. Time series analysis revealed that total medical expenditures and doctor's fee for inpatient will be progressively increased whereas drug expenditures for inpatient will be decreased. And there will be no change in length of stay. Based on the above results, the factors increasing medical cost and utilization should be identified and the method of cost containment for the elderly health care should be developed systematically.

• Journal of Korea Soil Environment Society
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• v.2 no.3
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• pp.3-21
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• 1997

The remediation of contamiated sites using currently available remediation technologies requires long term treatment and huge costs, and it is uncertain to achieve the remediation goal to drop contamination level to either back-ground or health-based standards by using such technologies. Intrinsic remediation technology is the remediation technology that relies on the mechanisms of natural attenuation for the containment and elimination of contaminants in subsurface environments. Initial costs for the intrinsic remediation may be higher than conventional treatment technologies because the most comprehensive site assessment for intrinsic remediation is required. Total remediation cost, however may be the lowest among the presently employed technologies. The applicability of intrinsic remediation in the contaminated sites should be theroughly investigated to achieve the remedial goal of the technology. This paper provides the frame of the extended site assessment procedure based on knowledge of biodegradability to evaluate the applicability of intrinsic remediation. This site assessment procedure is composed of 5 steps such as preliminary site screening, assessment of the current knowledge of biodegradability, selecting the appropriate approach, analyzing the contaminant fate and transport and planning the monitoring schedule. In the step 1, followings are to be decided 1) whether to go on the the detailed assessment or not based on the rules of thumb concerning the biodegradability of organic compounds, 2) which protocol document is selected to follow for detailed site assessment according to the site characteristics, contaminants and the relative distance between the contamination and potential receptors. In the step 2, the database for biodegradability are searched and evaluated. In the step 3, the appropriate biodegradability pathways for the contaminated site is selected. In the step 4, the fate and transport of the contaminants at the site are analyzed through modeling. In the step 5, the monitoring schedule is planned according to the result of the modeling. Through this procedure, users may able to have the rational and systematic informations for the application of intrinsic remediation. Also the collected data and informations can be used as the basic to re-select the other remediation technology if it reaches a conclusion not to applicate intrinsic remediation technology at the site from the site assessment procedure.