• Journal of the Korean Society of Radiology
• /
• v.14 no.4
• /
• pp.425-431
• /
• 2020

When a radiation generating device is installed in an export container due to COVID-19, the purpose of this study was to measure the space dose in the radiation room and to study the effectiveness of the shielding wall in the laboratory. Air dose measurement method was set behind the X-ray tube, 50 cm, 100 cm, 200 cm, and measured 12 locations. The dose values before and after the use of the movable radiation shielding wall were compared by measuring 3 locations behind the X-ray tube using the movable radiation shielding wall. The measured values were 50 cm on the left behind the X-ray tube: 1.446 μSv, behind the X-ray tube: 0.545 μSv, and 50 cm on the right behind the X-ray tube: 1.466 μSv. Measurements behind the radiation barrier were 0.190 μSv, 0.204 μSv, and 0.191 μSv. As a result of performing the corresponding sample t test of the average value according to the use of movable barrier walls, p <0.001 was found. As a result of the actual measurement, the medical exposure of the examiner due to the shielding wall in the laboratory decreased to 82.3%. In order to reduce occupational exposure in screening radiological laboratories, it is recommended that sufficient separation from radiation sources and the use of shielding walls are recommended.

• Journal of radiological science and technology
• /
• v.32 no.3
• /
• pp.261-270
• /
• 2009

The study examined the relationship between the compressed breast thickness and Average Glandular Dose (AGD) among 1,969 outpatients who went through breast X-ray in a university hospital for 10 months from July 1st, 2007 to April 30th, 2008. Then it analyzed the result acquired from 3,900 cases of Cranio-Caudal (CC) view, especially, when the breasts were compressed (13-15daN). The following is the conclusion driven from the relationship analysis. 1. The subjects aged in 40s and 50s were 2,679 out of 3,900 cases and this figure was 68.69% in all. 2. In terms of distribution depending on focus/filter, 41.0% was Mo/Mo, 34.8% was Mo/Rh, and 24.2% was Rh/Rh. 3. In terms of compressed breast thickness depending on focus/filter, the average thickness was 26.91 mm at Mo/Mo, 38.84 mm at Mo/Rh, and 48.80 mm at Rh/Rh. The average thickness of the entire cases was shown to be 36.27 mm. 4. AGD depending on focus/filter was 1.27 mGy at Mo/Mo, 1.55 mGy at Mo/Rh, and 1.42 mGy at Rh/Rh. The average glandular dose of the entire cases was shown to be 1.43 mGy. 5. The relationship of AGD depending on compressed breast thickness at Mo/Mo was y=0.0318x + 0.470 while it was y=0.0206x + 0.709 at Mo/Rh and y=0.0248x + 0.335 at Mo/Rh. It was highly influenced by the compressed breast thickness, however, more variation was detected at Mo/Mo depending on breast thickness.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.26 no.2
• /
• pp.99-107
• /
• 2006

Magnetic nondestructive testing is very useful far detecting a crack on the surface or near of the surface of the ferromagnetic materials. The distribution of the magnetic flux leakage (DMFL) on a specimen has to be obtained quantitatively to evaluate the crack. The magnetic camera is proposed to obtain the DMFL at the large lift-off. The magnetic camera consists of a magnetic source, magnetic lens, analog to digital converters (ADCs), interface, and computer. The magnetic leakage fields or the distorted magnetic fields from the object, which are concentrated on the magnetic lens, are converted to analog electrical signals tv arrayed small magnetic sensors. These analog signals are converted to digital signals by the ADCs, and are stored, imaged, and processed by the interface and computer. However the magnetic camera has limitations with respect to converting and switching speed, full range and resolution, direct memory access (DMA), temporary storage speed and volume because common ADCs were used. Improved techniques, such as those that introduce the operational amplifier (OP-Amp), amplify the signal, reduce the connection line, and use the low pass filter (LPF) to increase the signal to noise ratio are necessary. This paper proposes the exclusive embedded ADC including OP-Amp, LPF, microprocessor and DMA circuit for the magnetic camera to satisfy the conditions mentioned above.

• Health Policy and Management
• /
• v.5 no.1
• /
• pp.31-58
• /
• 1995

The Korean government achieved the universal coverage of health insurance in July 1989, and concomitantly introduced a new measure of regulated health care delivery system in using medical care. There are three reasons why the government took the new health care delivery system. Firstly, there was ample room for improving the allocative efficiency in the use of medical facilities. And the second one was to constrain the dramatic increase of medical demand under health insurance. Thirdly, and the most important reason was to alleviate the patient crowdedness in big general hospitals, particularly tertiary hospitals. There are essentially two different ways to control the use of health care : one is to cut the demand for health care, and the other to regulate behaviors of providers through the use of incentives/disincentives, demand-side approach or supply-side approach. The objective of this study is to examine whether or not medical care utilization behaviors under health insurance scheme have been changed among medical facilities such as clinic, hospital, general hospital and tertiary hospital in comparison with those before and after the introduction, particularly whether the patient crowdedness in tertiary hospitals has been alleviated or not. In order to conduct this study, the insurance claim data during the period of January 1989 and July 1992 were analyzed by focusing on diagnosis of both inpatients and outpatients, and especially the fifteen most frequent diseases in ambulatory care and the seven most frequent diseases in hospitalizatio. In addition, the same analyses were made on the changes in medical care utilization by specialty department. This was because the five departments, such as family medicine, ENT, eye, dermatology and rehabilitation, were exempted from applying the regulated health care delivery system in tertiary hospitals. The study revealed that a remarkable alleviation effect in the crowdness was noted for tertiary hospitals. This effect was most conspicuous for the most frequent mild diseases of both inpatient and outpatient care. For example, the fifteen most frequent OPD care at tertiary facilities have decreased as much as by 40%, of which 34% belonged to the cut in initial visits. Meanwhile, the proportion of those who used general hospitals and private practitioner's clinics have increased due to the shift of patients. The cases from the five special departments were also decreased, but not so much as other departments. A problem was noted that, as time passed by, the decreasing tendencies of crowdness at tertiary hospitals due to the regulated system became slightly smaller. Therefore, through complementary remedies are needed for the future implementation.

• Journal of Hospice and Palliative Care
• /
• v.16 no.2
• /
• pp.98-107
• /
• 2013

Purpose: This study was conducted to investigate how home-based hospice care is provided in Korea. Methods: From July 2011 through August 2011, 29 hospice facilities that provide home-based hospice care were surveyed using a questionnaire. Items included in the questionnaire were general characteristics of the organization, staff members, service programs, difficulties. Results: Among the surveyed, hospice care was hospital-based for 11 (37.9%) facilities, hospital-independent center-based care for four (13.8%) and home-based care only for 10 (34.5%). Near half the participants were located in Seoul and Gyeonggi-do. Caregivers included nurses for 62.1% of the participants, volunteers 62.0%, pastors 44.8%, social workers 37.9%, coordinators 31.0% and doctors 31.0%. The facilities offered service programs such as family counseling (96.6%), transfer to other facilities (93.1%), psychological support (89.7%), bereavement support (86.2%), dying care (79.3%), clinical care (75.9%) and spiritual support (75.9%). The major obstacles were financial issues (24.1%), lack of trained staff (20.7%) and staff members' lack of awareness of home-based hospice care (13.8%). Conclusion: In Korea, home-based hospice care is provided by an insufficient number of facilities. Moreover, the service providers are experiencing difficulties such as lack of trained staff, insufficient financial resource and staff's lack of awareness of home-based hospice care. It is necessary to increase the number of home-based hospice care facilities with consideration of even distribution across regions and standard staffing and service programs and develop related insurance policies.

• Korean Journal of Clinical Laboratory Science
• /
• v.49 no.4
• /
• pp.427-434
• /
• 2017

Species that belong to the Acinetobacter calcoaceticus-baumannii (Acb) complex are major causes of hospital-acquired infections. They are important opportunistic pathogens. These species are usually multidrug resistant (MDR), and the therapeutic options to treat the infections caused by these species are limited. In the present study, we investigated fluoroquinolone resistance mechanisms in 53 ciprofloxacin resistant Acinetobacter species isolates in Chungcheong, Korea. Antimicrobial susceptibilities were determined using the disk-diffusion method. Detections of genes and identification of mutations associated with fluoroquinolone resistance were carried out using PCR and DNA sequencing. In our study, 47 out of 53 ciprofloxacin resistant Acinetobacter isolates harbored sense mutations at the 83rd residue (serine to leucine) in the gyrA gene as well as at the 80th residue (serine to leucine) in the parC gene. Among the 47 isolates harboring sense mutations in gyrA and parC gene, 44 isolates were A. baumannii and 3 isolates were A. pittii. Plasmid-mediated quinolone resistance (PMQR) determinants were detected in isolates in our study. Among the 46 ciprofloxacin resistant A. baumannii isolates, 41 showed type A, B, or F banding patterns on their REP-PCR profiles. This result suggests that clonal relation and horizontal spreading of the bacterial isolates have been around hospitals in Chungcheong area. To prevent colonization and disseminations of fluoroquinolone resistance Acb complex isolates, continuous investigation and monitoring of antimicrobial resistant determinants of MDR isolates are needed.

• Journal of Preventive Medicine and Public Health
• /
• v.14 no.1
• /
• pp.43-51
• /
• 1981

The objective of the study is to measure the changes in measles infection and measles vaccination rates for the past 10 years in a rural area, Kang Wha. The study population were the entire children who were born between 1971 and 1950 in three townships (Sunwon, Naegae, Buleun) in Kangwha County. Two interview surveys were carried out during the 10 years of period, one in 1977 and the other in 1981. The data were collected by Family Health Workers through interview with structured questionnaires. The diagnosis of measles was mainly based on histories, symptoms and sighs of the disease. If a mother had reported measles history of her child, a public physician reviewed and decided the final diagnosis of the reported case. A retrospective cohort observation was done in order to see the trends of measles infections and measles vaccinations. The major findings were as follows; 1. The 5 year prevalence rate of measles vaccinations was 51.3% between 1971 and 1975 and 71.9% between 1976 and 1980 respectively. The difference between two periods was statistically significant (P<0.05). The secular trend of measles vaccinations showed increasing tendency from 1971 to 1978 and since then kept maintained. 2. In the birth cohort analysis of measles vaccinations, the vaccination rates, in general, were higher in the later cohort groups than that of earlier cohort groups. 9. The 5-year experience rates for measles infections were 24.3% between 1971 and 1975 and 17.2% between 1976 and 1980 respectively. This difference was statistically significant(P<0.05). The secular trend of experience rates for measles infections showed decreasing tendency from 1971 to 1980 except an outbreak in 1976. 4. The birth cohort analysis of experience rates for measles infections showed that the rate was higher in the later cohort groups than that of the earlier cohort groups. This decreasing tendency was prominent between $1973{\sim}1974$ and $1976{\sim}1977$. 5. The distribution of age specific incidence rates for measles infections showed unimodal curve with the peak at the age of 12 to 18 months. This findings were same in both two surveys. 6. Seasonal variations of the measles infections showed two peaks, one major peak in March through May and the another minor peak in September through December. 7. The 5-year reduction rate for measles infections among those vaccinated was 90.4% between 1971 and 1975 and 88% between 1976 and 1980.

• Journal of Preventive Medicine and Public Health
• /
• v.17 no.1
• /
• pp.31-36
• /
• 1984

In order to know about the utilization of health subcenter in a Korean rural community, a study was carried out through analyzing the records on the outpatients in Su-Dong Health Subcenter during 5 years from 1978 to 1982, and the following results were obtained. 1. The annual utilization rate of health subcenter of Su-Dong Myun showed decreasing tendency such as 946.6 in 1978, 886.4 in 1979, 736.5 in 1980, 708.3 in 1981 and 609.1 in 1982 per 1,000 people. 2. In terms of annual utilization rate of health subcenter by sex, utilization rate of female was higher than that of male such as in 1978 (male 908.6, female 986.3), 1979 (male 819.2, female 956.7) and 1981 (male 686.0, female 731.5) except 1980(male 790.0, female 683.3) and 1982(male 632.7, female 585.0). 3. Every year the 5 major diseases of the new patients cared in health subcenter were the same as follows; Diseases of the Respiratory System, Diseases of the Digestive System, Diseases of the Skin and Subcutaneous Tissue, Accident Poisoning and Violence, and Diseases of the Nervous System and Sensory Organ. 4. In terms of annual utilization rate of health subcenter by age, utilization rate of $0{\sim}4$ year group was highest every year such as 3,666.0 in 1978, 3,232.5 in 1979, 2,819.0 in 1980, 2,361.4 in 1981 and 2408.7 in 1982 per 1,000 people. 5. The average visiting times per case to health subcenter were not much different every year such as 1.75 times in 1978, 1.79 times in 1979, 1.69 times in 1980, 1.79 times in 1981, and 1.80 times in 1982. 6. The monthly utilization rates per 1,000 people of health subcenter had two peaks in February(40.9 in 1980 and 86.4 in 1981) and July(84.6 in 1980 and 72.1 in 1981) except 1982. 7. The distribution of new patients by the source of medical fee payment was follows; community health organization member 86.9%, medicaid program 6.5%, and medical insurance 6.6% in 1980 and community health organization member 76.8%, medicaid program 11.4%, and medical insurance 11.8% in 1981 and community health organization member 78.2%, medicaid program 14.8% and medical insurance 13.2% in 1982.

• Korean Journal of Remote Sensing
• /
• v.27 no.3
• /
• pp.235-258
• /
• 2011

The purpose of this study is to investigate climatological variations from the temporal and spatial surface particulate organic carbon (POC) estimates based on SeaWiFS spectral radiance, and to determine the physical mechanisms that affect the distribution of pac in the Gulf of Mexico. 7-year monthly mean values of surface pac concentration (Sept. 1997 - Dec. 2004) were estimated from Maximum Normalized Difference Carbon Index (MNDCI) algorithm using SeaWiFS data. Synchronous 7-year monthly mean values of remote sensing data (sea surface temperature (SST), sea surface wind (SSW), sea surface height anomaly (SSHA), precipitation rate (PR)) and recorded river discharge data were used to determine physical forcing factors. The spatial pattern of POC was related to one or more factors such as river runoff, wind-derived current, and stratification of the water column, the energetic Loop Current/Eddies, and buoyancy forcing. The observed seasonal change in the POC plume's response to wind speed in the western delta region resulted from seasonal changes in the upper ocean stratification. During late spring and summer, the low-density river water is heated rapidly at the surface by incoming solar radiation. This lowers the density of the fresh-water plume and increases the near-surface stratification of the water column. In the absence of significant wind forcing, the plume undergoes buoyant spreading and the sediment is maintained at the surface by the shallow pycnocline. However, when the wind speed increases substantially, wind-wave action increases vertical motion, reducing stratification, and the sediment were mixed downward rather than spreading laterally. Maximum particle concentrations over the outer shelf and the upper slope during lower runoff seasons were related to the Loop Current/eddies and buoyancy forcing. Inter-annual differences of POC concentration were related to ENSO cycles. During the El Nino events (1997-1998 and 2002-2004), the higher pac concentrations existed and were related to high runoffs in the eastern Gulf of Mexico, but the opposite conditions in the western Gulf of Mexico. During La Nina conditions (1999-2001), low Poe concentration was related to normal or low river discharge, and low PM/nutrient waters in the eastern Gulf of Mexico, but the opposite conditions in the western Gulf of Mexico.

• The Korean Journal of Applied Statistics
• /
• v.33 no.5
• /
• pp.527-540
• /
• 2020

While analyzing data, researching outliers, which are out of the main tendency, is as important as researching data that follow the general tendency. In this study we discuss the influence function for outlier discrimination. We derive sample influence functions of sample mean, sample variance, and sample standard deviation, which were not directly derived in previous research. The results enable us to mathematically examine the relationship between the empirical influence function and sample influence function. We can also consider a method to approximate the sample influence function by the empirical influence function. Also, the validity of the relationship between the approximated sample influence function and the empirical influence function is also verified by the simulation of random sampled data in normal distribution. As the result of a simulation, both the relationship between the two influence functions, sample and empirical, and the method of approximating the sample influence function through the emperical influence function were verified. This research has significance in proposing a method that reduces errors in the approximation of the empirical influence function and in proposing an effective and practical method that proceeds from previous research that approximates the sample influence function directly through empirical influence function by constant revision.