• Journal of the Korea Organic Resources Recycling Association
• /
• v.31 no.4
• /
• pp.29-39
• /
• 2023

In this study, an analysis of medical waste generation characteristics was conducted, differentiating between ordinary situation and the outbreaks of massive infectious diseases. During ordinary situation, prediction models for medical waste quantities by type, general medical waste(G-MW), hazardous medical waste(H-MW), infectious medical waste(I-MW), were established through regression analysis, with all significance values (p) being <0.0001, indicating statistical significance. The determination coefficient(R2) values for prediction models of each category were analyzed as follows : I-MW(R2=0.9943) > G-MW(R2=0.9817) > H-MW(R2=0.9310). Additionally, factors such as GDP(G-MW), the number of medical institutions (H-MW), and the elderly population ratio(I-MW), utilized as influencing factors and consistent with previous literature, showed high correlations. The total MW generation, evaluated by combining each model, had an MAE of 2,615 and RMSE of 3,353. This indicated accuracy levels similar to the medical waste models of H-MW(2,491, 2,890) and I-MW(2,291, 3,267). Due to limitations in accurately estimating the quantity of medical waste during the rapid and outbreaks of massive infectious diseases, the generation unit of I-MW was derived to analyze its characteristics. During the early unstable stage of infectious disease outbreaks, the generation unit was 8.74 kg/capita·day, 2.69 kg/capita·day during the stable stage, and an average of 0.08 kg/capita·day during the reduction stage. Correlation analysis between generation unit of I-MW and lethality rates showed +0.99 in the unstable stage, +0.52 in the stable stage, and +0.96 in the reduction period, demonstrating a very high positive correlation of +0.95 or higher throughout the entire outbreaks of massive infectious diseases. The results derived from this study are expected to play a useful role in establishing an effective medical waste management system in the field of health care.

• Korean Journal of Food Science and Technology
• /
• v.45 no.5
• /
• pp.531-536
• /
• 2013

We developed a simple, sensitive, and specific analytical method for prometryn using gas chromatography-mass spectrometry (GC-MS). Prometryn is a selective herbicide used for the control of annual grasses and broadleaf weeds in cotton and celery crops. On the basis of high specificity, sensitivity, and reproducibility, combined with simple analytical operation, we propose that our newly developed method is suitable for use as a Ministry of Food and Drug Safety (MFDS, Korea) official method in the routine analysis of individual pesticide residues. Further, the method is applicable in clams. The separation condition for GC-MS was optimized by using a DB-5MS capillary column ($30m{\times}0.25mm$, 0.25 ${\mu}m$) with helium as the carrier gas, at a flow rate of 0.9 mL/min. We achieved high linearity over the concentration range 0.02-0.5 mg/L (correlation coefficient, $r^2$ >0.998). Our method is specific and sensitive, and has a quantitation limit of 0.04 mg/kg. The average recovery in clams ranged from 84.0% to 98.0%. The reproducibility of measurements expressed as the coefficient of variation (CV%) ranged from 3.0% to 7.1%. Our analytical procedure showed high accuracy and acceptable sensitivity regarding the analytical requirements for prometryn in fishery products. Finally, we successfully applied our method to the determination of residue levels in fishery products, and showed that none of the analyzed samples contained detectable amounts of residues.

• Korea Journal of Hospital Management
• /
• v.9 no.1
• /
• pp.66-94
• /
• 2004

The objective of this study is to examine how to maximize the efficiency of hospital management by minimizing the unit cost of hospital operation. For this purpose, this paper proposes to develop a model of the profit maximization based on the cost minimization dictum using the statistical tools of arriving at the maximum likelihood values. The preliminary survey data are collected from the annual statistics and their analyses published by Korea Health Industry Development Institute and Korean Hospital Association. The maximum likelihood value statistical analyses are conducted from the information on the cost (function) of each of 36 hospitals selected by the random stratified sampling method according to the size and location (urban or rural) of hospitals. We believe that, although the size of sample is relatively small, because of the sampling method used and the high response rate, the power of estimation of the results of the statistical analyses of the sample hospitals is acceptable. The conceptual framework of analyses is adopted from the various models of the determinants of hospital costs used by the previous studies. According to this framework, the study postulates that the unit cost of hospital operation is determined by the size, scope of service, technology (production function) as measured by capacity utilization, labor capital ratio and labor input-mix variables, and by exogeneous variables. The variables to represent the above cost determinants are selected by using the step-wise regression so that only the statistically significant variables may be utilized in analyzing how these variables impact on the hospital unit cost. The results of the analyses show that the models of hospital cost determinants adopted are well chosen. The various models analyzed have the (goodness of fit) overall determination (R2) which all turned out to be significant, regardless of the variables put in to represent the cost determinants. Specifically, the size and scope of service, no matter how it is measured, i. e., number of admissions per bed, number of ambulatory visits per bed, adjusted inpatient days and adjusted outpatients, have overall effects of reducing the hospital unit costs as measured by the cost per admission, per inpatient day, or office visit implying the existence of the economy of scale in the hospital operation. Thirdly, the technology used in operating a hospital has turned out to have its ramifications on the hospital unit cost similar to those postulated in the static theory of the firm. For example, the capacity utilization as represented by the inpatient days per employee tuned out to have statistically significant negative impacts on the unit cost of hospital operation, while payroll expenses per inpatient cost has a positive effect. The input-mix of hospital operation, as represented by the ratio of the number of doctor, nurse or medical staff per general employee, supports the known thesis that the specialized manpower costs more than the general employees. The labor/capital ratio as represented by the employees per 100 beds is shown to have a positive effect on the cost as expected. As for the exogeneous variable's impacts on the cost, when this variable is represented by the percent of urban 100 population at the location where the hospital is located, the regression analysis shows that the hospitals located in the urban area have a higher cost than those in the rural area. Finally, the case study of the sample hospitals offers a specific information to hospital administrators about how they share in terms of the cost they are incurring in comparison to other hospitals. For example, if his/her hospital is of small size and located in a city, he/she can compare the various costs of his/her hospital operation with those of other similar hospitals. Therefore, he/she may be able to find the reasons why the cost of his/her hospital operation has a higher or lower cost than other similar hospitals in what factors of the hospital cost determinants.

• Korean Journal of Food Science and Technology
• /
• v.25 no.2
• /
• pp.105-108
• /
• 1993

A new devised conductivity meter was used in the rapid and convenient determination of salt contents of soysauce and margarine. The equation $(1){\sim}(5)$ was set up between the electric conductivity (x) for 100 times diluted solution of soysauce and the salt contents (y). y=0.083x-1.253 $(at\;15^{\circ}C)$ (1) y=0.077x-2.062 $(at\;20^{\circ}C)$ (2) y=0.071x-2.686 $(at\;25^{\circ}C)$ (3) y=0.066x-3.153 $(at\;30^{\circ}C)$ (4) y=0.062x-3.522 $(at\;35^{\circ}C)$ (5) y=(-0.001139t+0.0999)x+(-0.126t+0.557) $(temperature\;range;\;15{\sim}35^{\circ}C)$ (6) y=salt contents [%], x=conductivity $[{\mu}{\Omega}^{-1}{\cdot}cm^{-1}]$, $t=temp.\;[^{\circ}C]$. The salt contents could be estimated by the equation $(1){\sim}(6)$ and the measured conductivity. The estimated salt contents agreed with that determined by conventional method within 0.27[%] as salt contents. For margarine, the equation (7) was setup between the conductivity (x) and the salt contents (y) y=0.00266x+0.057 $(at\;20^{\circ}C)$ (7) y=salt contents [%], x=conductivity $[{\mu}{\Omega}^{-1}{\cdot}cm^{-1}]$ The salt contents estimated with the equation (7) and the measured condutivity agreed with that determined by conventional method within 0.028[%] as salt contents. The electric conductivity obtained with conductivity meter could be a valuable criteria salt contents test of Korean soysauce and margarine determining in a few second or minute by handy compact portable meter.

• Journal of radiological science and technology
• /
• v.40 no.2
• /
• pp.187-195
• /
• 2017

Early diagnosis for upper facial trauma is difficult by using the standard Water's view (S-Water's) in general radiograph due to overlapping of anatomical structures, the uncertainty of patient positioning, and specific patients with obese, pediatric, old, or high-risk. The purpose of this study was to analyze appropriate exposure angles through a comparison of two different protocols (S-Water's vs. reverse Water's view (R-Water's)) by using a head phantom. A head phantom and general radiograph with 75 kVp, 400 mA, 45 ms 18 mAs, and SID 100 cm. Images of R-Water's were obtained by different angles in the range of $0^{\circ}$ to $50^{\circ}$, which adjusted an angle at 1 degree interval in supine position. Survey elements were developed and three observers were evaluated with four elements including the maxillary sinus, zygomatic arch, petrous ridge, and image distortion. Statistical significant analysis were used the Krippendorff's alpha and Fleiss' kappa. The intra-class correlation (ICC) coefficient for three observers were high with maxillary, 0.957 (0.903, 0.995); zygomatic arch, 0.939 (0.866, 0.987); petrous ridge, 0.972 (0.897, 1.000); and image distortion, 0.949 (0.830, 1.000). The high-quality image (HI) and perfect agreement (PA) for acquired exposure angles were high in range of the maxillary sinus ($36^{\circ}-44^{\circ}C$), zygomatic arch ($33^{\circ}-40^{\circ}$), petrous ridge ($32^{\circ}-50^{\circ}$), and image distortion ($44^{\circ}-50^{\circ}$). Consequently, an appropriate exposure angles for the R-Water's view in the supine position for patients with facial trauma are in the from $36^{\circ}$ to $40^{\circ}$ in this phantom study. The results of this study will be helpful for the rapid diagnosis of facial fractures by simple radiography.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.13 no.3
• /
• pp.123-131
• /
• 2009

Purpose: We tested a sample of nuclear medicine workers at Korean healthcare institutions for internal contamination with radioactive isotopes, measuring concentrations and evaluating doses of individual exposure. Materials and Methods: The detection and measurement was performed on urine samples collected from 25 nuclear medicine workers at three large hospitals located in Seoul. Urine samples were collected once a week, 100~200 mL samples were gathered up to 6~10 times weekly. A high-purity germanium detector was used to measure gamma radiations in urine samples for the presence of radioactive isotopes. Based on the detection results, we estimated the amounts of intake and committed effective doses using IMBA software. In cases where committed effective doses could not be adequately evaluated with IMBA software, we estimated individual committed effective doses for radionuclides with a very short half life such as $^{99m}Tc$ and $^{123}I$, using the methods recommended by International Atomic Energy Agency. Results: Radionuclides detected through the analysis of urine samples included $^{99m}Tc$, $^{123}I$, $^{131}I$ and $^{201}Tl$, as well as $^{18}F$, a nuclide used in Positron Emission Tomography examinations. The committed effective doses, calculated based on the radionuclide concentrations in urine samples, ranged from 0 to 5 mSv, but were, in the majority of cases, less than 1 mSv. The committed effective dose exceeded 1 mSv in three of the samples, and all three were workers directly handling radioactive sources. No nurses were found to have a committed effective dose in excess of 1 mSv. Conclusions: To improve the accuracy of results, it may be necessary to conduct a long-term study, performed over a time span wide enough to allow the clear determination of the influence of seasonal factors. A larger sample should also help increase the reliability of results. However, as most Korean nuclear medicine workers are currently not necessary to monitored routinely for internal contamination with radionuclides. Notwithstanding, a continuous effort is recommended to reduce any unnecessary exposure to radioactive substances, even if in inconsequential amounts, by regularly surveying workplace environments and frequently monitoring atmospheric concentrations of radionuclides.

• Journal of Animal Science and Technology
• /
• v.48 no.6
• /
• pp.897-906
• /
• 2006

This study was conducted to determine effects of different supplementation periods (2, 3 and 4 months) of spent composts of Se-enriched mushrooms (Se-SMC) on plasma glutathione peroxidase (GSH-Px) activity and selenium deposition of finishing Hanwoo steers for the optimal supplementing period determination in order to produce Se-fortified Hanwoo beef. In the present study, 30 Hanwoo steers were allotted to treatments in six groups of five steers per pen. Treatments were separated into control and Se-SMC for each supplementation period. Dietary selenium contents were 0.1 and 0.9 ppm for control and Se-SMC treatments, respectively. At the end of each supplementation period, steers by periods were slaughtered to collect hind leg and liver samples for their selenium analyses. Blood samples were taken to analyze whole blood Se concentration and plasma GSH-Px activity at the last day of each supplementation period. Dry matter intakes were unaffected by Se-SMC and supplementation periods. In addition, average daily gain was not different between control and Se-SMC treatments and among supplementation periods. There was no difference for total body weight gain between control and Se-SMC treatments within each supplementation period. The supplementation of Se-SMC significantly (P<0.001) increased whole blood Se concentration, but whole blood selenium concentration was not affected by the supplementation period. Furthermore, plasma GSH-Px activity showed similar trend as shown in the pattern of whole blood Se concentration, but no difference by supplementation periods was observed. Selenium contents in hind legs significantly (P<0.05) increased with increasing supplementation periods, and also they were significantly (P<0.001) higher for Se-SMC supplementation groups in comparison to controls. However, there was no difference for selenium contents of hind legs between three and four months supplementation. Selenium contents in livers tended to slightly increase with increasing supplementation periods with no significant difference, but they were significantly (P<0.01) higher for Se-SMC supplementation groups compared with controls within the same period. The results indicated that the optimal Se-SMC supplementation period for the selenium deposition in Hanwoo steers might be around two or three months when we considered selenium contents in hind legs and livers.

• Journal of Animal Science and Technology
• /
• v.49 no.1
• /
• pp.41-50
• /
• 2007

Data from a comparative slaughter experiment with two hundreds of Korean native (Hanwoo) beef steers were utilized to determine net energy and protein requirements for growth (NEg and NPg). Eight randomly selected steers were used in the initial slaughter group of 6 month of age and the remaining steers allocated to treatments within two groups. The restricted groups were fed 1.2 to 1.5% concentrate per kg body weight (BW) in the growing period (6～12 month of age), 1.7 to 1.8% concentrate per kg BW in the early fattening period (13～18 month of age), and concentrate feed ad libitum in the late fattening period (19～30 month of age). Ad libitum groups were fed concentrate ad libitum through the whole period. Rice straw was offered ad libitum for 24 month of two feeding systems. The steers were slaughtered when animals reached every 2 month from 8 to 30 month of age. For all body composition determinations, whole empty body components were weighed, taken each proportional subsample was ground for chemical analysis. Equations developed with the pooled data to predicted NEg and NPg were similar to the equations of Japanese Feeding Standard for Beef Cattle (2000). First equations were developed to predicted NEg; NEg = 0.05332×LBW0.75×DG for restricted treatment and NEg = 0.04912×LBW0.75×DG for ad libitum treatment. Second equations were developed to predicted NPg; NPg = DG × (224.7－0.251×LBW) for restricted treatment and NPg=DG×(210.1－0.214×LBW) for ad libitum treatment.

• Korean Journal of Soil Science and Fertilizer
• /
• v.29 no.1
• /
• pp.34-43
• /
• 1996

Determining the actual evapotranspiration(ETa) of a crop, and appropriate water management of the crop based on the ETa are very important For increasing the yield. The present study aimed at determining ETa and crop coefficient of sesame growing under different climatic conditions with the transparent thin polyethylene film mulch(0.03 mm thick) and without this mulch. Bottomless cylindrical lysimeters(105cm in diameter, 120cm in height, protruded 20 cm above the soil surface) were installed on the field of sandy loam "Bonyang series" soil with a moderate drainage. The determination of ETa was performed by measuring each component of a model equation, $ETa=(R+I)-\{Ro+(D1+D2)\}+C{\pm}{\Delta}S$. Sesame, cv. "Ansan" was sown in two rows with the spacing of $50{\times}15cm$ on May 10 in 1991 and 1992. The mulching covers 80% of the soil surface. Sesame consumed the water of 139.0 mm(1.53 mm/day) and 171.2 mm(1.59 mm/day) in ETa without the film mulch, but that of 132.6 mm(1.46 mm/day) and 199.8 mm(1.85 mm/day) with its mulching through both years of 1991 and 1992, respectively. The ETa's accounted for 52 and 69% of the potential evapotranspiration(ETp) in the mulched crop, and 54 and 59% of ETp in the non-mulched crop 1991 through 1992, respectively. Its ETa's were much more and their gap between the mulching and non-mulching treatment was larger in 1992 than in 1991 as a result of the better climatic condition of 1992.

• Korean journal of applied entomology
• /
• v.43 no.4 s.137
• /
• pp.297-304
• /
• 2004

The development of Aphidoletes aphidimyza, an aphidophagous gall midge, was studied at various constant temperatures ranging from 15 to $35^{\circ}C$, with $65{\pm}5\%$ RH, and a photo-period of 16L:8D. When A. aphidimyra was fed either on Aphis gossypii or Myzus persicae, it took 43.9 and 44.5 days, respectively, to develop from egg to pupa at $15^{\circ}C$, whereas at $25^{\circ}C$, 14.3 and 15.8 days. The developmental zero was 10.7 and $10.0^{\circ}C$, respectively, while the effective accumuative temperatures were 210.8 and 245.5 day-degrees. The nonlinear shape of temperature-dependent development, shown by A. aphidimyza when fed on either species of the aphids, was well described by the modified Sharpe and DeMichele model. When distribution model of completion time of development for each growth stage was expressed as physiological age and fitted to the Weibull fuction, the completion time of development gradually shortened from egg to larva, and to pupa. In addition, the coefficient of determination $r^2$ ranged between 0.86-0.93 and 0.85-0.94, respectively providing a good approximation of cumulative developmental rates. The life span of adult was 8.7 and 9.2 days at $15^{\circ}C$, and 3.1 and 2.7 days at $30^{\circ}C$, respectively. Egg incubation period was relatively short at $35^{\circ}C$ but hatchability was less than $50\%$ and the mortality of the larva at $35^{\circ}C$ reached $100\%$. At $30^{\circ}C$, the time of development lengthened and the adult longevity was short suggesting ill effect of high temperatures. Even though the life span of adults at $15^{\circ}C$ was relatively long, none moved freely in the rearing cage and no oviposition occurred. Accordingly, in case A. aphidimyza is adopted to suppress phytophagus aphid populations, it could be applicable to cropping systems with ambient temperatures above $20^{\circ}C$ and below $30^{\circ}C$. Within this range, A. aphidimyza adults was observed to be active and oviposit fully.