• The Korean Journal of Nuclear Medicine Technology
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• v.28 no.1
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• pp.81-87
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• 2024

Purpose: CA 19-9 is the most widely used tumor marker for the diagnosis of digestive system tumor, especially pancreatic and biliary tract cancer. This study was conducted to improve the result value near reference range by comparing the reagents of CA 19-9 one step method and two step method. In addition, it was intended to establish a standard for selecting reagents. Material and Methods: 120 patients who visited the National Cancer Center in 2023 were selected as subjects for this study. The reagents used in the study were CA 19-9 IRMA kits (Shinjin, Korea) and three types of reagents were compared. Two step method reagent that is currently being used (A), one step method reagent (B) and two step method reagent improved by request (C) were compared and regression analysis was performed on their data. And we also performed recovery test, linearity test and hook effect test for each reagent. Result: There were 46 cases of reagent B in which the concentration value was lower than the result measured in reagent A that was previously used, and 77 cases of reagent C. As a result of regression analysis of reagents A, B, and C, the coefficients of determination of reagents A and B, reagents A and C, and reagents B and C were 0.653, 0.577, and 0.875. In the recovery rate test and the linearity test, the results of all reagents were good, and in the hook effect test, reagent B showed a hook effect at a low value. Conclusion: The improved reagent C appears to have been improved based on the concentration value of reagent B, which the manufacturer judged to be more stable at low concentrations. The hook effect in reagent B can be a fatal reason for disqualification when selecting reagents in general patient samples which high-concentration samples appear frequently. The first improved reagent C will be able to be used once it is confirmed that it has more stability for various concentration values.

• Korean Journal of Radiology
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• v.22 no.11
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• pp.1764-1776
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• 2021

Objective: This study aimed to validate a deep learning-based fully automatic calcium scoring (coronary artery calcium [CAC]_auto) system using previously published cardiac computed tomography (CT) cohort data with the manually segmented coronary calcium scoring (CAC_hand) system as the reference standard. Materials and Methods: We developed the CAC_auto system using 100 co-registered, non-enhanced and contrast-enhanced CT scans. For the validation of the CAC_auto system, three previously published CT cohorts (n = 2985) were chosen to represent different clinical scenarios (i.e., 2647 asymptomatic, 220 symptomatic, 118 valve disease) and four CT models. The performance of the CAC_auto system in detecting coronary calcium was determined. The reliability of the system in measuring the Agatston score as compared with CAC_hand was also evaluated per vessel and per patient using intraclass correlation coefficients (ICCs) and Bland-Altman analysis. The agreement between CAC_auto and CAC_hand based on the cardiovascular risk stratification categories (Agatston score: 0, 1-10, 11-100, 101-400, > 400) was evaluated. Results: In 2985 patients, 6218 coronary calcium lesions were identified using CAC_hand. The per-lesion sensitivity and false-positive rate of the CAC_auto system in detecting coronary calcium were 93.3% (5800 of 6218) and 0.11 false-positive lesions per patient, respectively. The CAC_auto system, in measuring the Agatston score, yielded ICCs of 0.99 for all the vessels (left main 0.91, left anterior descending 0.99, left circumflex 0.96, right coronary 0.99). The limits of agreement between CAC_auto and CAC_hand were 1.6 ± 52.2. The linearly weighted kappa value for the Agatston score categorization was 0.94. The main causes of false-positive results were image noise (29.1%, 97/333 lesions), aortic wall calcification (25.5%, 85/333 lesions), and pericardial calcification (24.3%, 81/333 lesions). Conclusion: The atlas-based CAC_auto empowered by deep learning provided accurate calcium score measurement as compared with manual method and risk category classification, which could potentially streamline CAC imaging workflows.

• Journal of the Korean Society of Radiology
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• v.7 no.1
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• pp.17-24
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• 2013

This study estimate radiation biological danger factor by measuring patient's exposed dose and propose the low way of patient's exposed dose in panoramic radiography. We seek correcting constant of OSL dosimeter for minimize the error of exposed dose's measurement and measure the Left, Right crystalline lens, thyroid, directly included upper, lower lips, the maxillary bone and the center of photographing that indirect included in panoramic radiography by using the human body model standard phantom advised in ICRP. In result, the center of photographing's level of radiation maximum value is $413.67{\pm}6.53{\mu}Gy$ and each upper, lower lips is $217.80{\pm}2.98{\mu}Gy$, $215.33{\pm}2.61{\mu}Gy$. Also in panoramic radiography, indirect included Left, Right crystalline lens's level of radiation are $30.73{\pm}2.34{\mu}Gy$, $31.87{\pm}2.50{\mu}Gy$, and thyroid's level of measured exposed dose can cause effect of radiation biological and we need justifiable analysis about radiation defense rule and substantiation advised international organization for the low way of patient's exposed dose in panoramic radiography of dental clinic and we judge need the additional study about radiation defense organization for protect the systematize protocol's finance and around internal organs for minimize until accepted by many people that is technological, economical and social fact by using panoramic measurement.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.2 no.1
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• pp.178-210
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• 1974

It needs to put into practice the systems analysis in the analysis of some operations and status of library for the purpose of systematizing the work of reforming in the new easier form to process, to storage, to retrieve and to make use of the increasing informations and data of library. In this study, some of systems which are generally using in every library was caught in the case study of K university library. Having analyzed them with the two methods of the flowcharting and mathematical analysis, we found the obstructive factors in operation. As the result of this research, it was gained the new system as the alternative one. A. Alternative System B. Advantages of alternative systems 1. In the reference room When it converts the present system into the new system, it can profit 6.771 won/user (13.815won-7.044won=6.771 won). Therefore, a half the average required cost of the present system can be saved. If this saving would be alloted for the cost 33,000won required to make the cataloging cards, it would be taken for 94 days (33,000 won ${\div}$ 6,771 won/user=4,874users. 4,874users ${\div}$ 52users/day=94days) to get it. The saving cost/year by the new system will be 95,417 won, and in the first year the initial cost (33,000won) reduces the saving cost to 62,417won. 2. In the periodical room The average required time for using the materials of the present system is 17 minutes/user and the average required cost/user is 23.775won, while the average required time of the new system is 4 minutes and the average required cost/user is 5.33won. Therefore, the new system has profit 4 times of the present system. Accordingly, it occurs when the dispersed periodical materials get together. 3. In the classification and cataloging When one processes - the oriental books - by the Linear Programming Technique, the maximum of the process can be increased from 11.6 volumes per librarian of the present system to 12 volumes per librarian of the new system increased 0.4 volume in a day, and cataloging by the manual printer can be shorten from 3 minutes per card of the present system to 1.5 minutes per card of the new system. Consequently, we can complete the other operations (books equipment, updating of cataloging cards, etc.) with 141 minutes which are saved in the course of the afore-mentioned works. 4. In the status of collections The average growth rate of 4 years from 1968 to 1971 is 9.825 %, and that of the purchased materials is 6.2% similar to the advanced nations, but it has the different position from 215,000 volumes by the Standard Degree for Establishment of College and University, and the difference between the total collections 151,671 volumes and Dunns' growth model ($N_t=N_oe^{-at}$) claimed by Leimkuhler 155,297 volumes in 1971 is 3,626 volumes, and for the purpose of compensation the difference, we found the fact that it needs to have the increased budget of 24~30% per year, Thus, if the budget of 24~30 % per year. Thus, if the budget would be increased per year as the rate of the afore-mentioned figure, it would be reached at the Standard Degree for Establishment of College and University in 1975, and thereafter, it can be decreased to the lebel which is able to maintain the growth rate of 5~6% per year.

• Journal of Food Hygiene and Safety
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• v.31 no.5
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• pp.327-334
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• 2016

This study was conducted to establish the standard method for the contents of biotin in milk formulas. To optimize the method, we compared several conditions for liquid extraction, purification and instrumental measurement using spiked samples and certified reference material (NIST SRM 1849a) as test materials. LC-MS/MS method for biotin was established using $C_{18}$ column and binary gradient 0.1% formic acid/acetonitrile, 0.1% formic acid/water mobile phase is applied for biotin. Product-ion traces at m/z 245.1 ${\rightarrow}$ 227.1, 166.1 are used for quantitative analysis of biotin. The linearity was over $R^2=0.999$ in range of $5{\sim}60{\mu}g/L$. For purification, chloroform was used as a solvent for eliminating lipids in milk formula. The linearity was over 0.999 in range of 5~60 ng/mL. The detection limit and quantification limit were 0.10, 0.31 ng/mL. The accuracy and precision of LC-MS/MS method using CRM were 103%, 2.5% respectively. Optimized methods were applied in sample analysis to verify the reliability. All the tested milk formulas were acceptable contents of biotin compared with component specification and standards for nutrition labeling. The standard operating procedures were prepared for biotin to provide experimental information and to strengthen the management of nutrient in milk formula.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.867-879
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• 2016

Since the 1970s, the region of its own pedestrian center and environmental pollution caused by exhaust gases have been reduced gradually in a continuous increase of the vehicle, school route the central business district, around the school, the sidewalk where the vehicle do not pass, facilities of minimum for the safety of pedestrians and systematic management of an area where an unspecified number and alleys impassable is insufficient. Recently, in response to the "Law for convenience enhancing safety and walking" is enforced in Korea, research on Pedestrian only Street has been actively about the government, the standard for calculating the weights of evaluation associated with it. it is a actuality, however, there are insufficient, evaluation for business promotion is being conducted evaluation polite manner by using, for example, scale residence time and purpose of the passengers as there is no car that has been carried out on a voluntary basis through the municipality have. In this study, by suggesting a method for the selection of the street without a car, make a survey by placing a purpose in the selection method presentation of the street with no car to be construction future, was researching. F.G.I (Focus Group Interview) survey, professors, staff in urban, traffic field of experts in order to present the weights for the evaluation of the Pedestrian only Street by using the evaluation index by type of Pedestrian only Street, was interviewed about the evaluation index for the conducted for professionals engaged in the engineering company, and randomly selected 200 peoples, weighted evaluation of the street with Pedestrian only Street was proposed. By classifying the items purpose and goals of the evaluation type by this by applying the weight, and present the weight of the detailed indicators each corresponding to each item, and scored on the basis of the result, in this paper it can be so that one methodology for the selection standard for the construction as Pedestrian only Street, and the weight of the evaluation of the type that has been derived, the selection and evaluation methods and then added to these criteria to settle careful study of the reference should be performed further.

• Progress in Medical Physics
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• v.24 no.2
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• pp.119-126
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• 2013

Due to the introduction of CR and DR, it has been neglected the use of the X-ray beam collimator and field size. This study examines nationwide survey of the proper use of collimator and field size by area in a specific field of plain radiography and the current status. Authors emphasized the need for the field size criteria, and propose a standard reference field size in each specific radiologic examination. Total 333 medical institutions (included in Seoul, Gyeonggi-do, Jeolla, Chungcheong, Gangwon-do, Busan area), were investigated in relation to the status of the X-ray beam collimation field size, type specific inspection areas, medical facilities, and image analyses by type to figure out whether they use the adjustment of image field to the specific examination. To assess the awareness and the impact of radiation exposure to the collimation adjustable, 168 radiographers who was working in 10 general hospitals, 10 hospitals, and 10 clinics, were surveyed how they haver adjusted the actual field size. We examine that 61.3% of medical institutions used the "Proper collimation" and only 49.9% of them employed proper one in lumbar spine densely crowded by major organs. 69% among general hospitals, and 65% among hospitals using DR system were using proper collimation. Radiographers recognized that proper adjustment of collimation could reduce the harmful radiation dose on patients. In the survey, 97.6% of respondents were aware of this fact, but only 83.3% of respondents did the adjustment of the size of the collimation field. The using of proper collimation field was low in the nationwide survey, so the effort to reduce the radiation dose on the patients is urgently needed. A unified standard for the field accompanied by thorough education should be needed.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.944-949
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• 2008

Purpose : As modern society has became more open, interest in healthy internal and external growth has increased, including that pertaining to penile length in children. A micropenis is defined as one where penile length is more than 2 SD (standard deviation) below the mean, and it can be traced back to chromosome and endocrine disorders. The authors executed this study to suggest guidelines for the study of the micropenis and standard information for penile length in Korean newborns. Methods : The subjects of this study were 168 male infants between 37 and 42 weeks of gestational age, none of whom had any complications during pregnancy or birth; each had been born in Daegu Fatima Hospital between February and June 2007. Penile length was measured using conventional stretched penile length measurement (CPLM) and syringe methods. Results : Penile length was $3.02{\pm}0.25cm$ (F=36.467, $R^2=0.180$, P<0.001) when measured with CPLM, and $3.29{\pm}0.26cm$ (F=9.149, $R^2=0.052$, P<0.001) with the syringe method. There was no statistically significant difference in the penile length of newborn infants as a result of taking measurements with the two methods, and both methods showed significance at 0.631 in terms of Pearson's correlation coefficient, at the level of P=0.01. Conclusion : In this study, penile length tended to be longer when gestational age was longer, and a micropenis can be assumed to be one less than 2.5 cm using CPLM and less than 2.8 cm using the syringe method. In the case of a concealed penis, the syringe method is helpful. When a micropenis is assumed, close observation by outpatient department personnel, and additional endocrine and chromosome studies should be undertaken after sufficiently consulting the parents.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.421-426
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• 2015

The objective of this paper is to look into the growth of Cryptomeria japonica stand in South Korea along with the evaluation on their yields, followed by their carbon stocks and removals. A total of 106 sample plots were selected from Jeonnam, Gyeongnam, and Jeju, where the groups of standard are grown. We only used 92 plots data except outlier. As part of the analysis, the Weibull diameter distribution was applied. In order to estimate the diameter distribution, the growth estimation equation for each of the growth factors including the height, the diameter at breast height, and the basal area was drafted out and the verification for each equation was examined. The site index for figuring out the forest productivity of Cryptomeria japonica stand for each district was also developed as a Schumacher model and 30yr was used as a reference age for the estimation of the site index. It was found that the site index for Cryptomeria japonica stand in South Korea ranges from 10 to 16 and this result was used as a standard for developing the stand yield table. According to the site 14 in the stand yield table, the mean annual increment (MAI) of the Cryptomeria japonica reaches $7.6m^3/ha$ on its 25yr and its growing stock is estimated to be at $190.1m^3/ha$. This volume is about $20m^3$ as high as that of the Chamaesyparis obtusa. Furthermore, the annual carbon absorptions for a Cryptomeria japonica stand reached the peak at 25yr, which is 2.14 tC/ha/yr, $7.83tCO_2/ha/yr$. When compared to the other conifers, this rate is slightly higher than that of a Chamaecyparis obtusa ($7.5tCO_2/ha/yr$) but lower than that of the Pinus koraiensis ($10.4tCO_2/ha/yr$) and Larix kaempferi ($11.2tCO_2/ha/yr$). With such research result as a base, it is necessary to come up with the ways to enhance the utilization of Cryptomeria japonica as timbers, besides making use of their growth data.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.1
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• pp.20-28
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• 2014

The three air quality monitoring sites, analysed simultaneously PM-10 and PM-2.5, ie. Ihyeondong in industrial area, Manchondong in residential area, Pyeongnidong in streetside, among 13 air quality monitoring sites in Daegu area, were investigated the concentration distribution characteristics of PM-2.5 and PM-10 in the last 2 years (2011~2012). PM-10 concentrations exceeded annual average reference value ($50{\mu}g/m^3$) in Ihyeondong ($52.5{\mu}g/m^3$) and Pyeongnidong ($60.9{\mu}g/m^3$) but satisfied in Manchondong ($44.9{\mu}g/m^3$). All PM-2.5 concentrations exceeded EPA annual standard value of the United States ($15{\mu}g/m^3$) in three points, but also exceeded new control annual standard value ($25{\mu}g/m^3$) coming into effect in 2015. Seasonal concentration of PM-10 appeared the order of spring > winter > fall > summer, and in the case of PM-2.5, the order was winter > spring > fall > summer. Monthly concentrations of PM-10 and PM-2.5 were highest in February and lowest in September. Diurnal concentrations of PM-10 and PM-2.5 increased from 7:00 AM, and recorded the highest concentration between 10:00 AM and 11:00 AM. And after 6:00 PM it lowered continuously and tended to show fixed concentrations from evening until early morning. In addition, the concentration of fine particles during the week was higher than the weekend. The fluctuation in industrial area was larger than the residential area. At the PM-2.5/PM-10 ratio, summer was generally high, spring was the lowest. And, when yellow sand occurred, it was 0.32 to 0.42. It was very low compared to 0.54 to 0.64 during non-yellow sand times. This paper for the state and the characteristics of Daegu' fine particles (PM-10, PM-2.5) will be valuable to future researches of fine particles and air pollution management.