• Korean Journal of Radiology
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• v.25 no.1
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• pp.11-23
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• 2024

Objective: To investigate whether reader training improves the performance and agreement of radiologists in interpreting unenhanced breast magnetic resonance imaging (MRI) scans using diffusion-weighted imaging (DWI). Materials and Methods: A study of 96 breasts (35 cancers, 24 benign, and 37 negative) in 48 asymptomatic women was performed between June 2019 and October 2020. High-resolution DWI with b-values of 0, 800, and 1200 sec/mm² was performed using a 3.0-T system. Sixteen breast radiologists independently reviewed the DWI, apparent diffusion coefficient maps, and T1-weighted MRI scans and recorded the Breast Imaging Reporting and Data System (BI-RADS) category for each breast. After a 2-h training session and a 5-month washout period, they re-evaluated the BI-RADS categories. A BI-RADS category of 4 (lesions with at least two suspicious criteria) or 5 (more than two suspicious criteria) was considered positive. The per-breast diagnostic performance of each reader was compared between the first and second reviews. Inter-reader agreement was evaluated using a multi-rater κ analysis and intraclass correlation coefficient (ICC). Results: Before training, the mean sensitivity, specificity, and accuracy of the 16 readers were 70.7% (95% confidence interval [CI]: 59.4-79.9), 90.8% (95% CI: 85.6-94.2), and 83.5% (95% CI: 78.6-87.4), respectively. After training, significant improvements in specificity (95.2%; 95% CI: 90.8-97.5; P = 0.001) and accuracy (85.9%; 95% CI: 80.9-89.8; P = 0.01) were observed, but no difference in sensitivity (69.8%; 95% CI: 58.1-79.4; P = 0.58) was observed. Regarding inter-reader agreement, the κ values were 0.57 (95% CI: 0.52-0.63) before training and 0.68 (95% CI: 0.62-0.74) after training, with a difference of 0.11 (95% CI: 0.02-0.18; P = 0.01). The ICC was 0.73 (95% CI: 0.69-0.74) before training and 0.79 (95% CI: 0.76-0.80) after training (P = 0.002). Conclusion: Brief reader training improved the performance and agreement of interpretations by breast radiologists using unenhanced MRI with DWI.

• Journal of the Daesoon Academy of Sciences
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• v.48
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• pp.41-155
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• 2024

Among the records that attest to the period from July to August of 1863, when Suwun was believed to have transmitted the orthodox lineage to Haewol, the oldest documents are The Collection of Suwun's Literary Works (水雲文集), The Collection of Great Master Lord's Literary Works (大先生主文集), and The Records of Dao Origin of Master Choe's Literary Collection (崔先生文集道源記書, hereafter referred to as The Records of Dao Origin). The records regarding Suwun in these three documents are considered to have originated from the same context. The variances embedded in the three documents have led to arguments about which documents accurately reflect the fact of orthodox lineage transmission. Additionally, these variances highlight the necessity of a review regarding the characteristics of early Eastern Learning, such as its faith and organizational systems. Accordingly, by thoroughly examining these three documents, it is possible to elucidate the chronological order, establishment-date, accuracy, descriptive direction, and characteristics of the faith system of early Eastern Learning as these are reflected in each document. If successful, this examination would provide a clearer description of the developmental process of Eastern Learning from 1860 to 1880, facilitating a more in-depth analysis of the significance embedded in various forms of discourse on the movement's orthodox lineage transmission. In comparing the three documents and contrasting them with related sources, the results of the textual examination assert that the documents within the lineage of The Collection of Suwun's Literary Works, given they lack a clear record of the event regarding Haewol's orthodox lineage succession, may be the first draft of The Collection of Great Master Lord's Literary Works and The Records of Dao Origin, as these texts distinctly include that record. This reflects that Haewol's succession was not precisely recognized within and outside of the Eastern Learning order until the time when The Collection of Great Master Lord's Literary Works and The Records of Dao Origin were published. This is further attested to by the fact that during the late 1870s, when various Yeonwon (fountainhead) factions of Eastern Learning began to converge around Haewol, and his Yeonwon became the largest organization within Eastern Learning. At that point, the order's doctrine was reinterpreted, and its organization was reestablished. In this regard, it is necessary to view Eastern Learning after Suwun-especially the orthodox lineage transmission to Haewol-from a perspective that considers it more as competing forms of discourse than as a historical fact. This view enables a new perspective on Haewol's Eastern Learning, which forms a distinct layer from Suwun's, shedding light on the relationship between Haewol and the new religious movements in modern-day Korea.

• Journal of Wetlands Research
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• v.26 no.2
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• pp.147-159
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• 2024

Lack of streamflow observations makes model calibration difficult and limits model performance improvement. Satellite-based remote sensing products offer a new alternative as they can be actively utilized to obtain hydrological data. Recently, several studies have shown that artificial intelligence-based solutions are more appropriate than traditional conceptual and physical models. In this study, a data-driven approach combining various recurrent neural networks and decision tree-based algorithms is proposed, and the utilization of satellite remote sensing information for AI training is investigated. The satellite imagery used in this study is from MODIS and SMAP. The proposed approach is validated using publicly available data from 25 watersheds. Inspired by the traditional regionalization approach, a strategy is adopted to learn one data-driven model by integrating data from all basins, and the potential of the proposed approach is evaluated by using a leave-one-out cross-validation regionalization setting to predict streamflow from different basins with one model. The GRU + Light GBM model was found to be a suitable model combination for target basins and showed good streamflow prediction performance in ungauged basins (The average model efficiency coefficient for predicting daily streamflow in 25 ungauged basins is 0.7187) except for the period when streamflow is very small. The influence of satellite remote sensing information was found to be up to 10%, with the additional application of satellite information having a greater impact on streamflow prediction during low or dry seasons than during wet or normal seasons.

• Pediatric Infection and Vaccine
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• v.31 no.1
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• pp.75-82
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• 2024

Purpose: As the coronavirus disease 2019 (COVID-19) pandemic ended, the number of patients with respiratory syncytial virus (RSV) pneumonia increased during the spring/summer of 2022. This study aimed to analyze the clinical features and antibiotic usage of children hospitalized for RSV pneumonia in a recently established general hospital in Sejong city. Methods: In this retrospective review, we included inpatients of the Pediatric Department of Chungnam National University Sejong Hospital diagnosed with RSV pneumonia between March 2022 and April 2023. Patients were divided into 2 groups: with and without antibiotic treatment. Demographic data, initial presentations, and clinical courses were reviewed. Results: A total of 116 patients with RSV pneumonia were hospitalized during this period, of which 102 were analyzed, excluding 14 with underlying diseases or who did not fall within the definition of pneumonia. The median age was 17 months. Diagnoses of bacterial infections (acute otitis media and sinusitis) were documented in 9.8% of cases. Intravenous (IV) antibiotics were administered in 46% of cases. The group receiving IV antibiotics showed higher inflammatory levels (C-reactive protein; CRP), more infiltration on initial chest X-rays, and longer fever duration. There was no difference in the length of hospitalization between the groups with and without IV antibiotics. Conclusions: This study showed a tendency for the attending physician to prescribe IV antibiotics to patients with longer fever duration, pulmonary infiltrations on the initial chest X-ray, and higher CRP levels. However, given the high rate of IV antibiotic usage compared to previous studies, care should be taken in antibiotic use.

• Korean Journal of Heritage: History & Science
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• v.57 no.2
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• pp.144-166
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• 2024

The Cultural Heritage Committee is an important organization that has been deliberating on important matters related to the preservation of cultural properties in the Republic of Korea for more than 60 years since 1962. The Cultural Heritage Preservation Committee was active in 1961, which was a short period of about a year, but the minutes prepared at the time confirmed that it had the following meanings. First of all, legally, it was meaningful in that the concept of cultural property or intangible cultural property was used for the first time in Korea in laws and regulations on the term of office of professional members. These matters became the basis for the operation of the current Cultural Heritage Protection Act and the Cultural Heritage Committee. The following confirms that, unlike previously known activities, they were active despite political upheaval at the time. In spite of rapid regime change at the time, the committee had no change in its members, and the meetings continued without interruption. At that time, there was an exclusive relationship between different groups in relation to the preservation of cultural heritage, and this relationship was confirmed by the minutes that disappeared with the establishment of the Cultural Heritage Management Bureau, which integrated these groups. Finally, the form of the minutes prepared then shows the form of documentation at the time, where it is confirmed that the traditional documentation format is changing into a new form. It can be good research material in terms of modern and contemporary bibliography. As discussed earlier, the Cultural Heritage Conservation Committee of 1961 has historical significance in terms of legal and actual activities. The reason why the committee's activities were low valued is presumed to be that the minutes and related documents prepared at the time were not organized well due to the lack of a related administrative system. The minutes of the Cultural Heritage Conservation Committee record various facts about cultural heritage policies and decisions at that time. Therefore, analysis and research on these contents can reveal more facts about the cultural heritage policies and perceptions of that time.

• Health Policy and Management
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• v.34 no.2
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• pp.196-210
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• 2024

Background: In January 2018, revised elderly fixed outpatient copayment for the elderly were implemented. When people ages 65 years and older receive outpatient treatment at clinic-level medical institutions (clinic, dental clinic, Korean medicine clinic), with medical expenses exceeding 15,000 won but not exceeding 25,000 won, their copayment rates have decreased differentially from 30%. This study aimed to examine the changes of health utilization of elderly after revised elderly fixed outpatient copayment. Methods: We used Korea health panel data from 2016 to 2018. The time period is divided into before and after the revised elderly fixed outpatient copayment. We conducted Poisson segmented regression to estimate the changes in outpatient utilization and inpatient utilization and conducted segmented regression to estimate the changes in medical expenses. Results: Immediately after the revised policy, the number of clinic and Korean medicine outpatient visits of medical expenses under 15,000 won decreased. But the number of clinic outpatient visits in the range of 15,000 to 20,000 won and Korean medicine clinic in the range of 20,000 to 25,000 won increased. Copayment in outpatient temporarily decreased. The inpatient admission rates and total medical expenses temporarily decreased but increased again. Conclusion: We confirmed the temporary increase in outpatient utilization in the medical expense segment with reduced copayment rates. And a temporary decrease in medical expenses followed by an increase again. To reduce the burden of medical expense among elderly in the long run, efforts to establish chronic disease management policies aimed at preventing disease occurrence and deterioration in advance need to continue.

• Journal of Environmental Impact Assessment
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• v.33 no.3
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• pp.131-141
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• 2024

The environmental impact assessment have been played important role for sustainable development of the country. Meantime, various studies have been conducted for scientific and effective environmental impact assessment. Howeverthe quantitative data such as regional distribution status and development characteristics according to the type of development project, environmental changes due to development projects, and spatial-temporal changes are insufficient, currently. In this study, we investigated the eco-friendliness of major development projects (industrial complex, urban development, tourist complexes, and waste disposal equipments) by integrating the EA-INDEX of each development projects which were reported by prior researches. As a result, we found that the eco-friendliness of development projects tended to gradually increase overtime due to the increase in eco-friendliness in the protection of living environment sector. The protection of living environment sector was a major factor in the the eco-friendliness of industrial complexes and urban development projects. In the case ofroad construction, landfill and tourist complex development projects, the natural environment conservation sector was a major factor in the eco-friendliness of the project. As a result of analyzing the eco-friendliness of development projects by local government, the eco-friendliness of development projects promoted and implemented in Ulsan, Jeonnam, and Gwangju was higher compared to other regions, and it was relatively low in Daejeon, Gyeongnam, and Daegu. This study is considered to be significant in that it conducted a quantitative analysis of the eco-friendliness of development projects carried out over a relatively long period of time throughout South Korea by dividing them by year and local government.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.1-25
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• 1982

Limnological study on the physico-chemical properties and biological characteristics of the Lake Ok-Jeong was made from May 1980 to August 1981. For the planktonic organisms in the lake, species composition, seasonal change and diurnal vertical distribution based on the monthly plankton samples were investigated in conjunction with the physico-chemical properties of the body of water in the lake. Analysis of temperature revealed that there were three distinctive periods in terms of vertical mixing of the water column. During the winter season (November-March) the vertical column was completely mixed, and no temperature gradient was observed. In February temperature of the whole column from the surface to the bottom was $3.5^{\circ}C$, which was the minimum value. With seasonal warming in spring, surface water forms thermoclines at the depth of 0-10 m from April to June. In summer (July-October) the surface mixing layer was deepened to form a strong thermocline at the depth of 15-25 m. At this time surface water reached up to $28.2^{\circ}C$ in August, accompanied by a significant increase in the temperature of bottom layer. Maximum bottom temperature was $r5^{\circ}C$ which occurred in September, thus showing that this lake keeps a significant turbulence Aehgh the hypolimnial layer. As autumn cooling proceeded summer stratification was destroyed from the end of October resulting in vertical mixing. In surface layer seasonal changes of pH were within the range from 6.8 in January to 9.0 in guutuost. Thighest value observed in August was mainly due to the photosynthetic activity of the phytoplankton. In the surface layer DO was always saturated throughout the year. Particularly in winter (January-April) the surface water was oversaturated (Max. 15.2 ppm in March). Vertical variation of DO was not remarkable, and bottom water was fairly well oxygenated. Transparency was closely related to the phytoplankton bloom. The highest value (4.6 m) was recorded in February when the primary production was low. During summer transparency decreased hand the lowest value (0.9 m) was recorded in August. It is mainly due to the dense blooming of gnabaena spiroides var. crassa in the surface layer. A. The amount of inorganic matters (Ca, Mg, Fe) reveals that Lake Ok-Jeong is classified as a soft-water lake. The amount of Cl, $NO_3-N$ and COD in 1981 was slightly higher than those in 1980. Heavy metals (Zn, Cu, Pb, Cd and Hg) were not detectable throughout the study period. During the study period 107 species of planktonic organisms representing 72 genera were identified. They include 12 species of Cyanophyta, 19 species of Bacillariophyta, 23 species of Chlorophyta, 14 species of Protozoa, 29 species of Rotifera, 4 species of Cladocera and 6 species of Copepoda. Bimodal blooming of phytoplankton was observed. A large blooming ($1,504\times10^3\;cells/l$ in October) was observed from July to October; a small blooming was present ($236\times10^3\;cells/l$ in February) from January to April. The dominant phytoplankton species include Melosira granulata, Anabaena spiroides, Asterionella gracillima and Microcystis aeruginota, which were classified into three seasonal groups : summer group, winter group and the whole year group. The sumner group includes Melosira granulate and Anabaena spiroides ; the winter group includes Asterionella gracillima and Synedra acus, S. ulna: the whole year group includes Microtystis aeruginosa and Ankistrodesmus falcatus. It is noted that M. granulate tends to aggregate in the bottom layer from January to August. The dominant zooplankters were Thermocpclops taihokuensis, Difflugia corona, Bosmina longirostris, Bosminopsis deitersi, Keratelle quadrata and Asplanchna priodonta. A single peak of zooplankton growth was observed and maximum zooplankton occurrence was present in July. Diurnal vertical migration was revealed by Microcystis aeruginosa, M. incerta, Anabaena spiroides, Melosira granulata, and Bosmina longirostris. Of these, M. granulata descends to the bottom and forms aggregation after sunset. B. longirostris shows fairly typical nocturnal migration. They ascends to the surface after sunset and disperse in the whole water column during night. Foully one species of fish representing 31 genera were collected. Of these 13 species including Pseudoperilnmpus uyekii and Coreoleuciscus splendidus were indigenous species of Korean inland waters. The indicator species of water quality determination include Microcystis aeruginosa, Melosira granulata, Asterionelta gracillima, Brachionus calyciflorus, Filinia longiseta, Conochiloides natans, Asplanchna priodonta, Difflugia corona, Eudorina elegans, Ceratium hirundinella, Bosmina longirostris, Bosminopsis deitersi, Heliodiaptomus kikuchii and Thermocyclops taihokuensis. These species have been known the indicator groups which are commonly found in the eutrophic lakes. Based on these planktonic indicators Lake Ok-Jeong can be classified into an eutrophic lake.

• Journal of agricultural medicine and community health
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• v.19 no.2
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• pp.141-158
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• 1994

To provide better health care services to the rural population, the government has made the Community Health Practitioner(CHP) a regular government official from April 1, 1992. This study was carried out to study the impact of officialization of CHP on the activities and management system of Primary Health Post(PHP). Fifty PHPs were selected by two stage sampling, cluster and simple random, from 595 PHPs in Kyungnam and Kyungpook provinces. Data were collected by a personal interview with CHPs and review of records and reports kept in the PHPs. The study was done for the periods of January 1-March 31, 1992 (before officialization) and January 1-March 31, 1993 (after officialization). Ninety-six percent of the CHPs wanted to become a regular government official in the hope of better job security and higher salary. The proportion of CHPs who were proud of their iob was increased from 24% to 46% after officialization. Those CHPs who felt insecure for their job decreased from 30% to 10%. Monthly salary was increased by 34% from 802,600 Won to 1,076,000 Won and 90% of the CHPs were satisfied with their salary, also more CHPs responded that they have autonomy in their work planning, implementation of plan, management of the post, and evaluation of their activity. There were no appreciable changes in such CHPs' activities as assessment of local health resources, drawing map for the catchment area, utilization of community organization, grasping the current population structure in the catchment area, keeping the family health records, individual and group health education, and school health service. However, the number of home visits was increased from 13.6 times on the average per month per CHP to 27.5 times. More mothers and children were referred to other medical facilities for the immunization and family planning services. Average number of patients of hypertension, cancer, and diabetes in three months period was decreased from 12.7 to 11.6, from 1.5 to 1.2, and 4.3 to 3.4, respectively. Records for the patient care, drug management, and equipment were well kept but not for other records. The level of record keeping was not changed after officialization. The proportion of PHPs which had support from the health center was increased for drug supply from 14.0% to 30.0%, for consumable commodities from 22.0% to 52.0%, for maintenance of PHP from 54.0% to 68.0%, for supply of health education materials from 34.0% to 44.0%, and supply of equipment from 54.0% to 58.0%. Total monthly revenue of a PHP was increased by about 50,000 Won; increased by 22,000 Won in patient care and 34,700 Won in the government subsidy but decreased in the membership due and donation. However, there was no remarkable changes in the expenditure. The proportion of PHPs which had received official notes from the health center for the purpose of guidance and supervision of the CHPs was increased from 20% to 38% during three months period and the average number of telephone call for supervision from the health center per PHP was increased from 1.8 to 2.1 times(p<0.01). However, the proportion of PHPs that had supervisory visit and conference was reduced from 79% to 62%, and from 88% to 74%, respectively. The proportion of CHPs who maintained a cooperative relationship with Myun Health Workers was reduced from 42% to 36%, that with the director of health center from 46% to 24%, that with the chief of public health administration section from 56% to 36%, and that with the chairman of PHP management council from 62% to 38%. Most of the CHPs (92% before and 82% after officialization) stated that the PHP management council is not helpful for the PHP. CHPs who considered the PHP management council unnecessary increased from 4% to 16%(p<0.05). Suggestions made by the CHPs for the improvement of CHP program included emphasis on health education, assurance of autonomy for PHP management, increase of the kind of drugs that can be dispensed by CHPs, and appointment of an experienced CHP in the health center as the supervisor of CHPs. The results of this study revealed that the role and function of CHPs as reflected in their activities have not been changed after officialization. However, satisfaction in job security and salary was improved as well as the autonomy. Support of health center to the PHP was improved but more official notes were sent to the PHPs which required the CHPs more paper works. Number of telephone calls for supervision was increased but there was little administrative and technical guidance for the CHP activities.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.32-36
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• 2016

Purpose In nuclear medicine examination, $^{131}I$ is widely used in nuclear medicine examination such as diagnosis, treatment, and others of thyroid cancer and other diseases. $^{131}I$ conducts examination and treatment through emission of ${\gamma}$ ray and ${\beta}^-$ ray. Since $^{131}I$ (364 keV) contains more energy compared to $^{99m}Tc$ (140 keV) although it displays high integrated rate and enables quick discharge through kidney, the objective of this study lies in comparing the difference in exposure dose of $^{131}I$ before and after wearing apron when handling $^{131}I$ with focus on 3 elements of external exposure protection that are distance, time, and shield in order to reduce the exposure to technicians in comparison with $^{99m}Tc$ during the handling and administration process. When wearing apron (in general, Pb 0.5 mm), $^{99m}Tc$ presents shield of over 90% but shielding effect of $^{131}I$ is relatively low as it is of high energy and there may be even more exposure due to influence of scattered ray (secondary) and bremsstrahlung in case of high dose. However, there is no special report or guideline for low dose (74 MBq) high energy thus quantitative analysis on exposure dose of technicians will be conducted based on apron wearing during the handling of $^{131}I$. Materials and Methods With patients who visited Department of Nuclear Medicine of our hospital for low dose $^{131}I$ administration for thyroid cancer and diagnosis for 7 months from Jun 2014 to Dec 2014 as its subject, total 6 pieces of TLD was attached to interior and exterior of apron placed on thyroid, chest, and testicle from preparation to administration. Then, radiation exposure dose from $^{131}I$ examination to administration was measured. Total procedure time was set as within 5 min per person including 3 min of explanation, 1 min of distribution, and 1 min of administration. In regards to TLD location selection, chest at which exposure dose is generally measured and thyroid and testicle with high sensitivity were selected. For preparation, 74 MBq of $^{131}I$ shall be distributed with the use of $2m{\ell}$ syringe and then it shall be distributed after making it into dose of $2m{\ell}$ though dilution with normal saline. When distributing $^{131}I$ and administering it to the patient, $100m{\ell}$ of water shall be put into a cup, distributed $^{131}I$ shall be diluted, and then oral administration to patients shall be conducted with the distance of 1m from the patient. The process of withdrawing $2m{\ell}$ syringe and cup used for oral administration was conducted while wearing apron and TLD. Apron and TLD were stored at storage room without influence of radiation exposure and the exposure dose was measured with request to Seoul Radiology Services. Results With the result of monthly accumulated exposure dose of TLD worn inside and outside of apron placed on thyroid, chest, and testicle during low dose $^{131}I$ examination during the research period divided by number of people, statistics processing was conducted with Wilcoxon Signed Rank Test using SPSS Version. 12.0K. As a result, it was revealed that there was no significant difference since all of thyroid (p = 0.345), chest (p = 0.686), and testicle (p = 0.715) were presented to be p > 0.05. Also, when converting the change in total exposure dose during research period into percentage, it was revealed to be -23.5%, -8.3%, and 19.0% for thyroid, chest, and testicle respectively. Conclusion As a result of conducting Wilcoxon Signed Rank Test, it was revealed that there is no statistically significant difference (p > 0.05). Also, in case of calculating shielding rate with accumulate exposure dose during 7 months, it was revealed that there is irregular change in exposure dose for inside and outside of apron. Although the degree of change seems to be high when it is expressed in percentage, it cannot be considered a big change since the unit of accumulated exposure dose is in decimal points. Therefore, regardless of wearing apron during high energy low dose $^{131}I$ administration, placing certain distance and terminating the administration as soon as possible would be of great assistance in reducing the exposure dose. Although this study restricted $^{131}I$ administration time to be within 5 min per person and distance for oral administration to be 1m, there was a shortcoming to acquire accurate result as there was insufficient number of N for statistics and it could be processed only through non-parametric method. Also, exposure dose per person during lose dose $^{131}I$ administration was measured with accumulated exposure dose using TLD rather than through direct-reading exposure dose thus more accurate result could be acquired when measurement is conducted using electronic dosimeter and pocket dosimeter.