• Journal of Radiation Industry
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• v.9 no.2
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• pp.85-90
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• 2015

Purpose: Time of operation has been reduced and accuracy of operation has been improved since C-arm, which offer real-time image of patient, was introduced in operation room. However, because of the contamination of patient, C-arm could not be used more appropriately. Therefore, this study is to know factors of controlling exposure dose, image quality and the exposed dose of health professional in operation room. Materials and methods: Height of Wilson frame (bed for operation) was fixed at 130 cm. Then, Model 76-2 Phantom, which was set by assembling manual of Fluke Company, was set on the bed. Head/Spine Fluoroscopy AEC mode was set for exposure condition. According to detector size of C-arm, the absorbed dose per min was measured in the 7 steps OFD (cm) from 10 cm to 40 cm (10, 15, 20, 25, 30, 35, 40 cm). In each step of OFD, the absorbed dose per min of same diameter of collimation was measured. Moreover, using Nero MAX Model 8000, exposure dose per min was measured according to 3 step of distance from detector (20 cm, 60 cm, 100 cm). Finally, resolution was measured by CDRH Disc Phantom and magnification of each OFD was measured by aluminum stick bar. Result: According to detector size of C-arm, difference of absorbed dose shows that the dose of 20 cm OFD is 1.750 times higher than the dose of 40 cm OFD. It means that the C-arm, which has smaller size of detector, shows the bigger difference of absorbed dose per min (p<0.05). In the difference of absorbed dose in the same step of OFD (from 20 cm to 40 cm), the absorbed dose of 9 inch detect or C-arm was 1.370 times higher than 12 inch' s (p<0.05). When OFD was set to 20 cm OFD, the absorbed dose of non-collimation case was approximately 0.816 times lower than the absorbed dose of collimation cases (p<0.05). When the distance was 20 cm from detector, exposed does includes first-ray and scatter-ray. When the distance was 60 cm and 100 cm from detector, exposed does includes just scatter-ray. So, there was the 2.200 times difference of absorbed does. Finally, when OFD was increased, spatial resolution was 4 to 5 step was increased. However, low contrast resolution was not relative. Moreover, there was 1.363 times difference of magnification (p<0.05). Conclusion: When C-Arm is used, avoiding contamination of patient is more important factor than reducing exposed dose of health professional in operation room. Just controlling exposure time is just way to reduce the exposed does of workers. However, in the case, non-probability influence could be occurred. Therefore, this study proved that the exposed dose will be reduced if the factors such as using small detector size of C-arm, setting OFD from 20 cm to 25 cm and non-collimating. Moreover, dose management of C-arm in the non-interesting area will be considered additionally.

• Journal of Korean Medical Science
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• v.33 no.52
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• pp.346.1-346.11
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• 2018

Background: To evaluate the therapeutic benefits of the treat-to-target (T2T) strategy for Asian patients with early rheumatoid arthritis (RA) in Korea. Methods: In a 1-year, multicenter, open-label strategy trial, 346 patients with early RA were recruited from 20 institutions across Korea and stratified into 2 groups, depending on whether they were recruited by rheumatologists who have adopted the T2T strategy (T2T group) or by rheumatologists who provided usual care (non-T2T group). Data regarding demographics, rheumatoid factor titer, anti-cyclic citrullinated peptide antibody titer, disease activity score of 28 joints (DAS28), and Korean Health Assessment Questionnaire (KHAQ) score were obtained at baseline and after 1 year of treatment. In the T2T group, the prescription for disease-modifying antirheumatic drugs was tailored to the predefined treatment target in each patient, namely remission (DAS28 < 2.6) or low disease activity (LDA) ($2.6{\leq}DAS28$ < 3.2). Results: Data were available for 163 T2T patients and 162 non-T2T patients. At the end of the study period, clinical outcomes were better in the T2T group than in the non-T2T group (LDA or remission, 59.5% vs. 35.8%; P < 0.001; remission, 43.6% vs. 19.8%; P < 0.001). Compared with non-T2T, T2T was also associated with higher rate of good European League Against Rheumatism response (63.0% vs. 39.8%; P < 0.001), improved KHAQ scores (-0.38 vs. -0.13; P = 0.008), and higher frequency of follow-up visits (5.0 vs. 2.0 visits/year; P < 0.001). Conclusion: In Asian patients with early RA, T2T improves disease activity and physical function. Setting a pre-defined treatment target in terms of DAS28 is recommended.

• Journal of The Korean Ophthalmological Society
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• v.59 no.12
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• pp.1129-1136
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• 2018

Purpose: To compare the postoperative clinical outcomes after cataract surgery and implantation using the BunnyLens $MF^{(R)}$ and $ReSTOR^{(R)}$ multifocal intraocular lenses. Methods: Sixty-five eyes implanted with multifocal intraocular lenses were divided into two groups involving either $ReSTOR^{(R)}$ (39 eyes) or BunnyLens $MF^{(R)}$ (26 eyes) lenses. In these two groups, the distant and near visual acuity, astigmatism, spherical equivalent, and contrast sensitivity test were examined at preoperative and postoperative 1 week, 8 weeks, and 24 weeks. We compared the clinical efficacy between the two groups before and after cataract surgery using statistical analysis. Results: The mean value of distant and near visual acuity, and spherical equivalent of both groups after intraocular lens implantation were significantly improved, compared with the preoperative values (p < 0.05), while there was no significant differences between the two groups (p > 0.05). The means of postoperative distant and near visual acuity, astigmatism, and contrast sensitivity test were not significantly different between $ReSTOR^{(R)}$ and BunnyLens $MF^{(R)}$ lenses (p > 0.05). The mean numeric error of spherical equivalent at the final postoperative 24 weeks was $-0.17{\pm}0.50$ diopters (D) for the $ReSTOR^{(R)}$ lenses and $-0.34{\pm}0.52D$ for the BunnyLens $MF^{(R)}$ lenses (p > 0.05). Conclusions: BunnyLens $MF^{(R)}$ and $ReSTOR^{(R)}$ lenses showed no significant difference in clinical efficacy, including distance and near vision, spherical equivalent error, and contrast sensitivity test after cataract surgery. However, it should be noted that BunnyLens $MF^{(R)}$ lenses had a tendency toward myopic shift compared with $ReSTOR^{(R)}$ lenses.

• Korean Journal of Remote Sensing
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• v.14 no.4
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• pp.353-365
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• 1998

Light absorption coefficient per unit mass of particles, i.e., specific absorption coefficient, is important as one of the main parameters in developing algorithms for ocean color remote sensing. Specific absorption coefficient of chlorophyll ($a^*_{ph}$) and suspended sediment ($a^*_{ss}$) were analyzed with a spectrophotometer using the "wet filter technique" and "Kishino method" for the seawater collected in the Yellow and Mediterranean Sea. An improved data-recovery method for the filter technique was also developed using spectrum slopes. This method recovered the baselines of spectrum that were often altered in the original methods. High $a^*_{ph}({lambda})$ values in the oligotrophic Mediterranean Sea and low values in the Yellow Sea were observed, ranging 0.01 to 0.12 $m^2$/mg at the chlorophyll maximum absorption wavelength of 440 nm. The empirical relationship between $a^*_{ph}$(440nm) and chlorophyll concentrations () was found to fit a power function ($a^*_{ph}$=0.039 $^{-0.369}$), which was similar to Bricaud et al. (1995). Absorption specific coefficients for suspended sediment ($a^*_{ss}$) did not show any relationship with concentrations of suspended sediment. However, an average value of $a^*_{ss}$ ranging 0.005 - 0.08 $m^2$/g at 440nm, was comparable to the specific absorption coefficient of soil (loess) measured by Ahn (1990). The morepronounced variability of $a^*_{ss}$ than $a^*_{ph}$ was determined from the variable mixing ratio values between particulate organic matter and mineral. It can also be explained by a wide size-distribution range for SS which were determined by their specific gravity, bottom state, depth and agitation of water mass by wind in the sea surface.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.219-228
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• 2009

The construction procedures and artificial turf maintenance program on golf course definitely influence on the distortion of its environment. Soil microbial communities in soil profile were affected directly by those practises on turf areas. In Jeju island, the environmental impact assessment has been required to apply the first quality class granular activated carbon(GAC), which has a high absorbent character to agricultural chemicals, on the soil profiles of golf green system to reduce the pesticide leaching to ground water. This research was carried out to analyze the changes of microbial communities and chemical properties on soil profiles where GAC had been applied at the construction stage at two golf courses in Jeju. The changes of soil microbial population and chemical properties associated with construction methods of soil profile and agrochemical management program were analyzed by monthly at the surface and sub-soil profiles during April through October, 2007. The total numbers of bacteria and fungi, soil moisture content, soil physio-chemical properties were measured on greens and fairways of the both golf courses with different GAC treatment on the green and fairway soil profiles. The results showed that GAC had positive effects on the water holding capacity, pH and EC, however, it did not improved the holding capacity of available nutrients ${NO_3}^-,{NH_4}^+$, and phosphorus by its sorption phenomenon. In microbial count test, the total numbers of bacteria and fungi showed a great variation during sampling dates. That may directly relate to the agrochemical application, however, the ratio of total bacterial number versus total fungus number showed a constant value on a sub-soil of 15~30cm depth. Thus, the construction method of GAC in soil profile, and application of fertilizer and pesticide, both impacted on the changes of microbial population. It's means that the construction method of soil profile and turf management using agro-materials might greatly affect on the turfgrass culture and the environment of golf course.

• Korea journal of population studies
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• v.11 no.1
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• pp.58-75
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• 1988

1.Objectives of the Study It is a well known fact that a prompt and reliable data on demographic information is essential in a proper planning and evaluation of any program of national or community level. Especially vital statistics are an important demographic component among demographic information. Realizing the importance of vital statistics, the government has made some efforts for years to improve the vital registration system which has a close relationship with the production of vital statistics. However, it is still observed that there are some limitations in utilizing vital registration data due to considerable amount of vital events which are never registered and registered but not in time or inaccurately, even though vital registration system in Korea has sound legal basis. In this connection, the objectives of the study is as follows :(1) To examine some problems of the vital registration system in various aspects, (2) To make improvement programme of continuous Demographic Survey as a supplementary source of vital statistics, and (3) To find out some alternatives for making it possible to produce and utilize the reliable vital statistics by developing analytical methodologies on that. 2. Current Situation of Vital Registration System All the vital events, i.e. births, deaths, marriages and divorces, are to be registered in time under the Civil Registration Law, Statistics Law and Regulation on Vital Statstics as a duty of people. Some recent tendencies in each of recent registration are summarized as below: (1) The completeness of vital registration .Out of all births which are occurred during a year, around 75% of those compared to the estimates are registered in the year of occurrence. .In case of death registration, the percentage of registration in the year of occurrene has been gradually increased from 86.2% in the year of 1980, but it is still below the level of 90% compared to the estimates. .The percentage of registration for marriages and divorces in the year of occurrence out of total registered numbers was revealed to be 69% and 73% respectively in 1985. (2) Continuous Demographic Survey .It is a kind of sample survey for the purpose of producing reliable vital statistics which could not be provided by the vital registration. .It covers about 17, 000 sample households at national level and important information for vital events are collected in every month by 323 expertized enumerators who are regular staff of the government. .Although the result of the survey seems to be more reliable than of vital registration, the reliability of the data is still bellow the acceptable level if compared with relevant information from other sources such as population census or special surveys. 3. Problems of Vital Registration System There are four major obstacles in improving vital registration system in Korea; (1) In general, policy priority is not given on any programme of improving vital registration system. It is, therefore, very difficult to formulate comprehensive programme through having cooperation from related authorities and sufficient financial assistance. (2) In all the laws related and system itself, there is substantial degree of overlap and irrationality. Registration of each vital event is maintained according to several laws and regulation such as Civil Registration Law, Statistics Law, Resident Registration Law and Regulation on Vital Statistics. However they are mutually overlapped and overall supervision can not be done systematically due to lack of co-operation among the authorities concerned. (3) The administration of vital registration system seems to be working inefficiently, because of most of civil servants who are in charge of vital registration are lacking of conception on vital statistics and also there is a certain extent of regidity in handling the works. Therefore, they are doing their jobs in a passive way. (4) A substantial proportion of vital events occurred is not registered within the legal time limit (i.e. within one month after the occurrence in case of birth and death) or not registered forever. Some of social customs and superstitution seem to be the potential causes especially in case of births and deaths. 4. Recommendations for the Improvement of Vital Statistics (1) Reporting systems such as civil registration, vital statistics and resident registration should be integrated under the single law. Also, administrative supervision, personnel and budget with regard to the registration system should be under the control of a single ministry. (2) It is necessary to simplify the procedures and methods of reporting vital events, i.e., reducing number of sheets of the form, making corrections easily, reducing registration items, etc. (3) Continuous Demographic Survey as a supplementary source of vital registration should be improved and special ad-hoc surveys should be conducted wth regular interval. (4) In-depth analysis should be done using various sources of data on vital statistics. 5. Concluding Remarks From this study, we can notice that temporary campaign and motivation programs are not sufficient to improve the quality of vital statistics. Strong intentions and continuous efforts of the government are needed for the improvement of the vital registration system. Furthermore, most of the data collected through the registration are not properly analyzed and utilized, partly due to the lack of appreciation among high-level governmental officials of the need for vital statistics. It is, therefore, requested that long-term improvement programs of vital statistics be implemented with policy priority and continuous efforts be given to this purpose as a long-term goal of development in Korea.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.1135-1147
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• 2021

In order to geometrically correct high-resolution satellite imagery, the sensor modeling process that restores the geometric relationship between the satellite sensor and the ground surface at the image acquisition time is required. In general, high-resolution satellites provide RPC (Rational Polynomial Coefficient) information, but the vendor-provided RPC includes geometric distortion caused by the position and orientation of the satellite sensor. GCP (Ground Control Point) is generally used to correct the RPC errors. The representative method of acquiring GCP is field survey to obtain accurate ground coordinates. However, it is difficult to find the GCP in the satellite image due to the quality of the image, land cover change, relief displacement, etc. By using image maps acquired from various sensors as reference data, it is possible to automate the collection of GCP through the image matching algorithm. In this study, the RPC of KOMPSAT-3A satellite image was corrected through the extracted matching point using the UAV (Unmanned Aerial Vehichle) imagery. We propose a pre-porocessing method for the extraction of matching points between the UAV imagery and KOMPSAT-3A satellite image. To this end, the characteristics of matching points extracted by independently applying the SURF (Speeded-Up Robust Features) and the phase correlation, which are representative feature-based matching method and area-based matching method, respectively, were compared. The RPC adjustment parameters were calculated using the matching points extracted through each algorithm. In order to verify the performance and usability of the proposed method, it was compared with the GCP-based RPC correction result. The GCP-based method showed an improvement of correction accuracy by 2.14 pixels for the sample and 5.43 pixelsfor the line compared to the vendor-provided RPC. In the proposed method using SURF and phase correlation methods, the accuracy of sample was improved by 0.83 pixels and 1.49 pixels, and that of line wasimproved by 4.81 pixels and 5.19 pixels, respectively, compared to the vendor-provided RPC. Through the experimental results, the proposed method using the UAV imagery presented the possibility as an alternative to the GCP-based method for the RPC correction.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.322-340
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• 2021

Due to climate change and its consequential spring temperature rise, flowering time of Robinia pseudoacacia has advanced and a simultaneous blooming phenomenon occurred in different regions in South Korea. These changes in flowering time became a major crisis in the domestic beekeeping industry and the demand for accurate prediction of flowering time for R. pseudoacacia is increasing. In this study, we developed and compared performance of four different models predicting flowering time of R. pseudoacacia for the entire country: a Single Model for the country (SM), Modified Single Model (MSM) using correction factors derived from SM, Group Model (GM) estimating parameters for each region, and Local Model (LM) estimating parameters for each site. To achieve this goal, the bloom date data observed at 26 points across the country for the past 12 years (2006-2017) and daily temperature data were used. As a result, bloom dates for the north central region, where spring temperature increase was more than two-fold higher than southern regions, have advanced and the differences compared with the southwest region decreased by 0.7098 days per year (p-value=0.0417). Model comparisons showed MSM and LM performed better than the other models, as shown by 24% and 15% lower RMSE than SM, respectively. Furthermore, validation with 16 additional sites for 4 years revealed co-krigging of LM showed better performance than expansion of MSM for the entire nation (RMSE: p-value=0.0118, Bias: p-value=0.0471). This study improved predictions of bloom dates for R. pseudoacacia and proposed methods for reliable expansion to the entire nation.

• The Journal of KAIRB
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• v.3 no.2
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• pp.19-27
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• 2021

Purpose: This study aimed to analyze the knowledge levels, attitudes, and factors affecting the choices on the education of the participants who completed their education of persons conducting clinical trial workers, and to assess the problems of the current education system for clinical trial workers, leading to improvements. Methods: Clinical trial workers (including principal investigators/subinvestigators, members of the Institutional Review Board [IRB], clinical research coordinators) who were affiliated to one of the 4 university hospitals running their own clinical trial center and IRB in Daegu and completed their education of persons conducting clinical trial workers were the subjects of this study. One hundred seven online questionnaires were answered from 2021-04-02 to 2021-04-17. Descriptive statistics and Pearson correlation analysis were used to analyze the acquired data. Independent t-test and 1-way analysis of variance were used to analyze the differences in the knowledge levels and attitudes following the characteristics of the education participants. Results: The baseline characteristics of the 107 participants were as follows: the majority of the participants were female (72.0%), were in their 30s (36.4%), had a nursing major (29.0%), were clinical research coordinators (63.6%), had never experienced a principal investigator (79.4%), had participated 3 or more educations (58.9%), had completed their maintenance course (55.1%), had 5 or more years of clinical trial experiences (34.6%). The fields on which participants had low levels of objective knowledge were "types and preparations on audits of clinical trials," "regulations on clinical trials (Pharmaceutical Affairs Act, Korea Good Clinical Practice)." The difficulties that the participants faced were on "annual educations" and "lack of information regarding the educations." Factors that showed significant differences in objective knowledge were sex (p=0.02), number of educations (p=0.004), the curriculum of 2020 (p=0.001). Age (p=0.004), having experienced a principal investigator (p=0.006), number of educations (p<0.001), the curriculum of 2020 (p<0.001), clinical trial career (p=0.001) were factors that significantly affected subjective knowledge. Attitudes toward the education were positively correlated with objective knowledge (r=0.20, p=0.04) and subjective knowledge (r=0.32, p=0.001). Major sources through which information on educations was acquired were "institutional notices," and major factors affecting the choices on the education were "when the education took place" and "where the education took place." "Within the affiliated institution," "Online classes (recorded)" and "IRB and review processes" were each the most preferred place, mode, and content of the education. Conclusion: Knowledge levels varied largely among participants who completed their education of persons conducting clinical trial workers, depending on their characteristics such as the number of educations. Participants also complained about their lack of information on educations. The quality of education may be improved if clinical trial organizations are designated as education facilities. Education programs must be developed considering the knowledge level and demand of the participants. Furthermore, as offline classes may be impossible due to pandemics such as the coronavirus disease 2019, the development of diverse and sophisticated online classes is looked forward to.

• Journal of radiological science and technology
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• v.44 no.5
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• pp.525-534
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• 2021

In order to provide high-quality medical services to the public and contribute to the improvement of public health, it is necessary to enact an independent law according to the work of radiological technologists. Therefore, this study intends to review the regulations related to radiographers in the Medical Service Technologists, etc. Act. and to present opinions and directions for enactment of individual laws for radiological technologists. An online survey was conducted to 15,000 radiological technologists working in medical institutions and education sites in Korea; 1,027 people (6.85%) responded. The questionnaire consisted of 3 questions on demographic characteristics, 5 questions on the scope of work, and 12 questions on the revision of the Medical Service Technologists, etc. Act. and the establishment of the Radiological Technologist Independent Act. Reliability and factor analysis were performed on 9 questions measured on a Likert 5-point scale in "Revision of the Medical Service Technologists, etc. Act. and the establishment of the Radiological echnologist Independent Act" among the questionnaire items. Reliability for the total 9 questions was Chronbach α=0.728. There was a high perception that the regulations related to radiological technologists were insufficient in the current Medical Service Technologists, etc. Act., and the perception that examinations performed by radiological technologists at medical institutions were included in medical practice was high. If the Radiological Technologist Independent Act is enforced, a high percentage of respondents said that they could receive legal protection through the institutionalization of the scope of work, that the status of radiological technologists would be improved, and the scope of work would be expanded. The response that the scope of work of radiological technologists should be included was the highest at 96.6%. In the analysis according to demographic characteristics, it was found that 96.7% of the respondents were agreed regardless of the factors. Radiological technologists will have to work hard to secure the public health by coping with new radiology devices, procedures and treatment methods. Therefore, as the results of this study, it is expected that the enactment and implementation of the Radiological Technologist Independent Act will contribute to the improvement of the quality of treatment for patients and to the public health.