• Journal of the Korean Society of Radiology
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• v.14 no.4
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• pp.487-494
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• 2020

The distance between the source and the detector, the diameter of the detector, and the volume effect of the radiation source result in a change in solid angle at the detector entrance, which affects the determination of detection efficiency by causing a difference in path length within the detector. A typical analysis method for calculating solid angles was useful only for a source (⁶⁰Co) with a simple geometric structure, so in this experiment, the distance between the detector and the source was measured by switching on for up to 25 cm with the reference point of window cap 0.5 cm. In addition, 450 and 1000 ㎖ Marinelli beaker of standard volumetric sources were closely adhered to the detector. For circular point sources co-axial with the detector, the change in the solid angle to the distance from the detector window is equal to half the square radius of the source versus the square radius of the detector, if the resulting relationship of the calculation analysis results in the detector being less than the radius of the source. Since the solid angular difference is 0.5 the result of Monte Carlo is acceptable. The relationship between detector and source distance is shown. Solid angles have been verified to decrease rapidly with distance. Measurement and simulation results for a volumetric source show a difference of ±1.01% from a distance of 0 cm and less than 4 % when the distance is reduced to 5 and 10 cm. It can be seen that the longer distance, the smaller efficiency angle, and the exponential increase in attenuation as the energy decreases, is reflected in the calculation of efficiency. Thus, the detection efficiency has proved sufficient for the use of solid angle and Monte Carlo codes.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.1
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• pp.111-126
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• 1998

In this study, radiographic evaluation was made using panoramic radiography and cross-sectional tomography of SCANORA/sup (R)/ in male and female adults in their 20's on the relationship between the maxillary sinus floor and the apex of the maxillary molar, to test the accuracy and effectiveness of the cross-sectional tomography, and to use this information in the assessment of preop. and postop. root canal treatment, apical surgery, extraction and implantology. Forty-one adults with an average age of 24.4 years were studied using panoramic radiography and cross-sectional tomography. In panoramic view and cross-sectional view, the position of the apices of maxillary molars were classified as separated, contacted, or protruded type; the general shape of the maxillary sinus floor was evaluated horizontally and vertically from cross-sectional tomography. The accuracy of each radiography was tested using maxilla from 5 fresh cadavers from the Anatomy Lab at Yonsei University Dental College, and panoramic view and cross-sectional tomography were taken in the same condition as with the patients. The results were as follows: 1. Panoramic view and cross-sectional view were taken in the maxilla specimen, and the actual distance between the maxillary sinus floor and the tooth apices were measured in the specimen; the median values of the distance from the tooth apices to the maxillary sinus floor in the panoramic view, cross-sectional view and in the actual maxilla specimen were 2.83 mm, 4.51mm, and 4.l5mm, respectively. In the cross-sectional view, the measured distance was close to the actual distance but in the panoramic view, the measured distance was far from the actual distance. 2. When the results of the panoramic view and cross-sectional view were compared, 40.5％ of the results agreed with each other in the two radiographic methods and buccal roots of the 2nd molar were the closest to the maxillary sinus floor in the cross-sectional tomography. 3. In cross-sectional view, when the vertical relationship of the maxillary sinus floor and maxillary roots was assessed, in 1st molars, type II (the sinus floor that extends down to the buccolingual furcation area) was predominant, while in 2nd molars, type I (the sinus floor located above the level connecting the buccal and lingual apices) was predominant. In the horizontal relationship, in 1st molars, type II (the lowest floor of the maxillary sinus located in between the buccal and lingual roots) was predominant; in 2nd molars, type I (the lowest floor of the maxillary sinus located on the buccal side of the buccal roots) and type II appeared in similar frequency. In conclusion, the SCANORA/sup (R)/ cross-sectional tomography was more effective than the frequently used panoramic view, in that the relationship of the maxillary molars and maxillary sinus floor can be evaluated more accurately and the buccolingual cross-sectional view can also be observed. And maxillary sinus floor that was close to maxillary 2nd molar had tendency to be located on buccal side than that close to 1st molar. Therefore, cross-sectional tomography is an effective and accurate method to evaluate the position of the teeth in relation to the sinus floor preoperative and can be easily used to diagnose localized periapical lesions. Also, the image quality obtained was quite satisfactory.

• Management & Information Systems Review
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• v.32 no.4
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• pp.81-101
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• 2013

The purpose of this study was to examine the effects of mental similarity and internal locus of control, which are the characteristics of an organizational member, and individualism and power distance, which are an individual's sense of value, on mentoring function in an informal mentoring relationship of ROK army. For corroborative analysis, the sample was collected from 547 questionnaires, which contain validate data out of 1,000 questionnaires distributed to junior officers working at ROK army's division level unit. The data proved that, First, mental similarity and internal locus of control positively effected upon mentoring function. Second, individualism positively effected upon mentoring function while power distance had a negative effect on it. Thus in an informal mentoring relationship of ROK army, a mentee perceived as he or she gains more support from mentoring function when a mentee recognizes higher mental similarity, individualism, and is in an internal locus of control. On the other hand, a mentee who perceived higher power distance felt as he or she gets less support from mentoring function. Through this investigation, the significance of influential components of mentoring function in a mentoring relationship of ROK army was demonstrated, and these research results could be highly supportive for a future research based on mentoring relationship.

• Safety and Health at Work
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• v.7 no.3
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• pp.237-243
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• 2016

Background: This study examined the relationship between interhandle distances and upper limb exertion during simply pushing and pulling of a cart with four swivel wheels, defined by a roll box pallet (RBP) in a Japanese industrial standard. Methods: Six healthy young male participants were asked to push and pull an RBP at a distance of 5.2 m under six conditions corresponding to different interhandle distances (40 cm, 60 cm, and 80 cm) and weights (130 kg and 250 kg). The upper limb exertion was studied by shoulder abduction and flexion, and elbow flexion, as well as surface electromyogram (EMG) in shoulder extensor, and elbow flexor and extensor. Participants were required to provide subjective evaluations on operability after each trial. Results: Subjective operability indicated that a narrower interhandle distance had a better operability for pushing. Interhandle distance was also related to upper limb exertion especially for pushing. A narrow interhandle distance caused smaller shoulder adduction but larger elbow flexion. The normalized EMG data revealed that muscular activity became smaller with a narrow interhandle distance in shoulder extensor. During the pulling task, elbow flexion was smaller at a narrow interhandle distance, although subjective operability and normalized EMG were not significantly varied. Conclusion: A wider interhandle distance, such as 80 cm, was not suitable in the forwardbackward movement of the RBP. Therefore, this study concluded that an interhandle distance of 40 cm would be suitable for pushing and pulling an RBP to protect the workers' hands against the risk of injury by installing inner handles.

• Journal of the Korea Society of Computer and Information
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• v.26 no.7
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• pp.119-126
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• 2021

Due to the prolonged COVID-19, distance lectures are expected to continue for a considerable period of time. Research on factors affecting distance lecture quality and learner satisfaction is essential. The purpose of this study is to examine the relationship between distance lecture quality (system quality, information quality, service quality, interaction quality), self-efficacy, and learner satisfaction, and to suggest theoretical and practical implications for the effective operation of distance lectures. A survey was conducted for university students taking distance lectures, and 197 questionnaires were used for empirical analysis. The collected data were analyzed by SPSS 25.0 and AMOS 21.0. As a result; First, distance lecture quality (system quality, information quality, service quality, interaction quality) was found to have a positive effect on self-efficacy. Second, distance lecture quality (system quality, information quality, service quality, interaction quality) was found to have a positive effect on learner satisfaction. Third, self-efficacy was found to have a positive effect on learner satisfaction. Based on the analysis results, the implications and limitations of this study are presented.

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1294-1297
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• 2007

To define diversity of domestic radish, we analysis genetic relationship of anti-fungal protein genes from several domestic radish (Raphanus sativus L.) seeds. We have isolated from domestic radish (Baekwoon) anti-fungal protein named RAP[12]. In this report, we isolate RNAs and raw protein from radish seeds then, RT-PCR analysis was done with another known anti-fungal sequences of radish from Gene Bank/EMBL and anti-fun- gal, anti-yeast activity were done against Bot교tis cenerea, Saccharomyces cerevisiaeι Candida albicans with it's raw proteins. The anti-fungal activity was shown used all seeds but anti-yeast activity was shown only two seeds (Myungsan, Baekwoon). RT-PCR products (about 0.2 Kb) were not shown only two seeds. To identify the sequencing relationship of the domestic radish, we have cloned and sequenced RAP genes of the radish and analysis the sequence relationship with clustalw program. Thus we report the result that there are some different relationship between domestic radish and known other radish's anti- fungal protein[15].

• Imaging Science in Dentistry
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• v.38 no.2
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• pp.95-101
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• 2008

Purpose: To assess the positional relationship between the maxillary sinus floor and the apex of the maxillary first molar using cone beam computed tomograph (CBCT). Materials and Methods: CBCTs from 127 subjects were analysed. A total of 134 maxillary first molars were classified according to their vertical and horizontal positional relationship to the maxillary sinus floor and measured according to the distance between the maxillary sinus floor and the maxillary first molar. Results: Type III (The root projected laterally on the sinus cavity but its apex is outside the sinus boundaries) was dominated between 10 and 19 years and type I (The root apex was not in contact with the cortical borders of the sinus) was dominated (P<0.05) between 20 and 72 years on the vertical relationship between the maxillary sinus floor and the apex of the maxillary first molar. The maxillary sinus floor was located more at the apex (78.2%) than at the furcation (21.3%) for the palatal root. The distance from the root apex to the maxillary sinus floor confined to type I was increased according to the ages (P<0.05). Type M (The maxillary sinus floor was located between the buccal and the palatal root) was most common (72.4%) on the horizontal relationship between the maxillary sinus floor and the apex of the maxillary first molar. Conclusion: CBCT can provide highly qualified images for the maxillary sinus floor and the root apex of the maxillary first molar.

• Journal of the Korean housing association
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• v.22 no.5
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• pp.47-57
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• 2011

The purpose of this research is to demonstrate the necessity of conserving and maintaining eco-parks by estimating their economic value. Wonheung-ee Park in Sannam 3 District of Cheongju City was chosen as the subject and a quantitative estimation was conducted. The quantitative analysis utilized the hedonic price model that estimates the value of non-market goods. The summarized results of this study are follows. The subject park influenced the prices of its neighboring apartments. The most important factor was the distance between the park and the subject apartment. When the distance was longer than 400m, the impact was greatest. The quantitative assessment also showed that apartment prices and the distance between an apartment and the park had a negative relationship. When the distance increased by 1%, apartment prices decreased by 0.430%. This means that within a certain distance, the closer an apartment is to the park, the higher is the price. Demonstrating the economic value of eco-parks, this study also supports the importance of preserving eco-areas. It generally shows that when we develop a city, we should refrain destroying the ecosystem.

• Journal of the Korean Home Economics Association
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• v.50 no.7
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• pp.13-20
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• 2012

This study aimed to find the association between geographic proximity and program participation at a Healthy Family Support Center (HFSC). Drawing demographic and geographic information from the participant list at a local HFSC in Seoul for the period 2009 to 2011, this study calculated the geographic distance from the individual residence to the center for 2,343 participants. We found that single time participants had a longer distance from their residence to the center than multiple time participants. When we compared the proximity by program areas, we found that the geographic distance to the center was shorter among education program participants than among non participants. However, there was no difference in the other areas of programs. In terms of the target group, the distance was shorter among adult program participants. Finally, the average distance among participants in multiple session programs was shorter. The results of this study indicated that the relationship between geographic proximity and program participation depended on program areas, target groups, and the number of sessions.

• BMB Reports
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• v.46 no.6
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• pp.305-309
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• 2013

The determination of relatedness between individuals in a family is crucial in analysis of common complex diseases. We present a method to infer close inter-familial relationships based on SNP genotyping data and provide the relationship coefficient of kinship in Korean families. We obtained blood samples from 43 Korean individuals in two families. SNP data was obtained using the Affymetrix Genome-wide Human SNP array 6.0 and the Illumina Human 1M-Duo chip. To measure the kinship coefficient with the SNP genotyping data, we considered all possible pairs of individuals in each family. The genetic distance between two individuals in a pair was determined using the allele sharing distance method. The results show that genetic distance is proportional to the kinship coefficient and that a close degree of kinship can be confirmed with SNP genotyping data. This study represents the first attempt to identify the genetic distance between very closely related individuals.