• Journal of radiological science and technology
• /
• v.30 no.4
• /
• pp.373-379
• /
• 2007

Purpose : There is difference between PET and PET/CT method on their transmission image for attenuation correction. The CT image is used for attenuation correction on PET/CT and the parameters of CT may be affected on PET image. We performed the phantom study to evaluate whether the change of CT parameters(kilovolts peak and milliampere) affect standardized uptake value(SUV) on PET image. Material and Method: The data spectrum lung phantom containing diluted [18F]fluorodeoxyglucose ([18F]FDG) solution(1.909 mCi for phantom 1, $913\;{\mu}Ci$ for phantom 2) was used. The CT images of phantom were acquired with varying parameters (80, 100, 120, 140 for kVp, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 for mA). The PET images were reconstructed with the each CT images and SUVs were compared. Result : The SUVs of phantom 1 reconstructed with each 80, 100, 120 and 140 kVp showed $12.26{\pm}0.009$, $12.27{\pm}0.005$, $12.27{\pm}0.006$ and $12.27{\pm}0.009$, respectively. The SUVs of phantom 2 revealed $4.52{\pm}0.043$, $4.53{\pm}0.004$, $4.52{\pm}0.007$ and $4.52{\pm}0.005$ with elevation of voltage. There was no statistically significant difference of SUVs between groups based on various kVp. Also SUVs of phantom 1 and 2 showed no significant change with elevation of milliampere in CT parameter. Conclusion : The parameters of CT did not significantly affect SUV on PET image in our study. Therefore we can apply various parameters of CT appropriated for clinical conditions without significant change of SUV on PET CT image.

• Journal of Technologic Dentistry
• /
• v.10 no.1
• /
• pp.159-169
• /
• 1988

Fixed prosthetic appliance is the restorations of damaged teeth with cast metal or porcelain, and of replacing missing teeth with fixed, or cemented prosthesis. Successfully treating a patient by means of fixed prosthodontics requires the thoughtful combination of dentist and dental laboratory technician. In order to know the satisfaction of dentisits about fixed prosthetic appliances-porcelain, precious and non precious metal-, this study was conducted for 69 practicing dentisis in Pusan during Fed. to Mar. 1988 using a questionnaire method and was analyzed by the use of percentage, $X^2$-test The results are obtained as follow: 1. General characteristics of the respondents, The rate of age distribution of practcing dentists responded was as follow : 31$\sim$35 age group is 29.0%, 51$\sim$55age group 18.8%, 41$\sim$45 age group and 46$\sim$50 group each 11.6%, 36$\sim$40 age group and 56$\sim$60 age group 8.7%, over 60 age group 7.3%, below 30 age group 4.3% respectively. The tate of term of practice experience distribution of dentists responded was as follow : 6$\sim$10 year group 26.1%, 25$\sim$25year group 18.8%, 11$\sim$15 years group and 16~20 years group each 13.0%, below 5 years group and over 30 years group each 10.2%, 26$\sim$30 years group 8.7% in order. The rate of respondents’ degree was follow : bachelor group 81.2%, doctor group 13.0%, master group 5.8% in order. The rate of respondents’completed medical specialist course was as follow : non-complete group 75.4%, complete group 24.6%. The rate of having own laboratory in respondents’clinic was as follow : no having own laboratory group 58.0%, having own labiratory group 42.0% The rate of being lab. technician in respondent;s clinic was as follow: non-being lab. technician group 91.3%, being lab. technician group 8.7%. The rate of transactional commercial dental lab. numbers was as follow : I dental lab. group 40.6%, 2 dental lab. group 30.4%, 3 dental lab. group 20.3%, production at own lab. group 8.7% 2. Cognitions about the respondent's job, About cognition of patient numvers, there were neither many nor few group 62.3%, few group 17.4%, many group 15.9%, too many group 4.4% in order.(P<.01) As compared with the ratio of dentists to patient prothetic treatment, there were moderate level group 46.4%, high level group 33.6%, low level group 18.8% in order.(P<.01) By job satisfaction of respondents, the highest percentage group was satisfied group 44.9%, neither astisfied nor disstified group 33.3%, dissatisfied group 14.5%, much satisfied group 7.3%(P<.01). As compared with the level of prosthetics price, the were moderate level group 71.0%, low level group 23.2%, high level group 5.8%(P<.01) 3. Satisfaction and assessment of dissatisfied factor of the fixed prosthetic appliance, As compared with the satisfaction of al prosthetic appliance, there were neither satisfied nor dissatisfied group 59.4%, satisfied group 20.3% dissatisfied group 18.8%, much satisfied group 1.5% in order.(P<.01). About precious and non precious metal crown and bridge, there were neither satisfied nor dissatisfied group 60.9%, satisfied group 24.6%, dissatisfied group 11.6%, much satisfied group 2.9% in order.(P<.01) The reat of respondent;s satisfaction about porcelain crown and bridge was as follow : neither satisfied nor dissatisfied group 43.5%, dissatisfied group 33.3%, satisfied group 21.7%, much satisfied group 1.5%(P<.01). The rate of respondent's dissatisfied factor item of precious and non precious metal crown and bridge was as follow : inadequate margin fit item 39.1% respondent, inadequate occlusion item 24.6%, inadequate adaptation item 23.2%, poor anat omic form item 15.9%, inadequate contact item 31.9%, improper polishing item 4.4%, the rest item 11.6% respectively. The rate of respondent's dissatisfied factor item of porcelain crown and bridge was as follow : inadequate margin fit item 52.2%, inadequate occlusion item 2.9%, inadequate adaptation item 10.1%, poor anatomic form item 11.6%, improper polishing item 1.5%, shade mismatching item 71%, the rest item 7.2% respectively. The rate of cognition of respondents’ about cause of dissatisfied factor on fixed prosthetic appliance by item was as follow : deficiency of sincerity item 55.1%, deficiency of knowledge about work item 47.8%, deficiency of experience item 15.9%, poor quality of using material item 5.8%, the rest item 2.9% respectively.

• Journal of Life Science
• /
• v.19 no.4
• /
• pp.532-537
• /
• 2009

Previous studies reported that the N-methyl-D-aspartate (NMDA) receptor is related to alcohol dependence in terms of developing withdrawal or tolerance, however, it is controversial whether NMDA receptor antagonists are effective in preventing relapse in alcohol-dependent patients or not. The purpose of this study was to investigate the effect of memantine, an NMDA receptor antagonist, on alcohol intake in C57BL/6 mice, which prefer drinking hereditarily. Using limited access procedures in C57BL/6 mice in the state of alcohol dependence, vehicle, naltrexone 1.0 mg/kg or, memantine 5, 25, or 50 mg/kg i.p. was administered respectively for twelve days. Medication effects on 2-hours alcohol, 22-hour water, and 24-hour food intake and body weight were studied. Using repeated measure ANOVA, the naltrexone 1 mg/kg, memantine 5, 25, or 50 mg/kg, and vehicle groups showed significant medication by day interaction (naltrexone, df=4, F=11.827, p<0.01, memantine 5 mg/kg, df=4, F=7.999, p<0.01; memantine 25 mg/kg, df=4, F=6.199, p<0.05; memantine 50 mg/kg, df=4, F=10.522, p<0.01) in 2-hour alcohol intake. In 3 memantine groups, there was no significant medication by day interaction with the vehicle group in 22-hour water intake, 24-hour food intake, or body weight. The naltrexone and vehicle groups showed significant medication by day interaction in body weight, but not in 22-hour water or 24-hour food intake. From these results, it is suggested that memantine treatment can affect alcohol intake in mice. Therefore, it is possible that a pure NMDA receptor antagonist is effective in preventing relapse in alcohol-dependent patients.

• Journal of dental hygiene science
• /
• v.11 no.2
• /
• pp.91-97
• /
• 2011

The aim of this study was to investigate the prevention effect of oral disease on the school-based toothbrushing program(SBTBP) in Daejeon in 30 months. The experimental subjects were the 5th grade's 70 students who have gone to school with the school-based toothbrushing program since the 3th-grade. The control school was located in close geographical area with similar economical status. The questionnaire about oral health knowledge and behavior was done by self-recording. After one dentist examined the dental caries and periodontal status, the gingival crevicular fluid(GCF) was collected with #25 paperpoint for 1 miniutes. Matrix Metalloproteinase(MMP)-9 in GCF was analyzed by ELISA. The SBTBP group had the upper oral health knowledge than the control significantly(p<0.001), but, the SBTBP group had no difference of the oral health behavior from the control. Although the SBTBP group had the lower plaque index than the control significantly(p=0.02), the SBTBP group had no difference of the gingival index, calculus index and the concentration of MMP-9 in GCF from the control. In conclusion, The SBTBP had the effect to reduce the dental plaque and to improve the oral health knowledge. On the other hand, the effect to prevent dental caries and periodontal disease of SBTBP was not clear.

• Journal of Korean Ophthalmic Optics Society
• /
• v.11 no.3
• /
• pp.281-291
• /
• 2006

The aim of this study was performed the clinical test using Netspeg lens for good visual acuity on subjects with abnormal refraction status. The subjects of one hundreds adults (fifty males, fifty females, mean=21 years, range=19 to 24) were recorded. The subjects were researched the history including the systemic health, medication, genetics, allergy, systemic disease and ocular disease. The refraction test was recorded the monocular and binocular using objective method. Visual acuity was performed the binocular status using the Netspeg lens and CR-39. Stereopsis test was performed the titmus fly and TNO at near distance using Netspeg lens and CR-39. The P-VEP test was used the 16 pattern size(Bausch Lomb, production in USA) with three channels. Also Subjects viewed the p-vep stimulus with binocular vision through the corrected visual acuity using the Netspeg lens and CR-39. The contrast sensitivity test was performed the contrast sensitivity chart(pelli-Robertson, USA) at 1m distance using the Netspeg lens and CR-39. The ultrastructure of surface on the Netspeg lens and CR-39 was observed the SEM(JMS-5800, made in Japan). The results of this study was as follows: 1. In corrected visual acuity of abnormal refraction using the Netspeg lens and CR-39, the Netspeg lens wearer were acquired the good visual field and clear visual acuity comparative to CR-39 wearer in the subject vision test. however the comfort of visual acuity was similar results in the Netspeg lens and CR-39. Also the subjects of Netspeg lens wearer was good visual acuity more than CR-39 wearer and in the analysis of P-VEP, the amplitude of wave on Netspeg lens used appears to be better through the CR-39(p>0.5). Besides, on the contrast sensitivity, the Netspeg lens wearer was good results than CR-39. The value on stereopsis with TNO by Netspeg lens wearer was better than CR-39 in results. However, in the stereopsis test with Titmus, the Netspeg lens and CR-39 wearer was similar results. 2. The ultrastructure of Netspeg lens surface was the smooth and fine shape more than CR-39. Also, Netspeg lens have a fine line structure in ultrastructure. In conclusion, the results of this study conformed that the surface ultrastructure of Netspeg lens used is more specific pin hole design structure than CR-39. This study indicated that the vision of Netspeg lens used have a better than CR-39 in the corrected visual acuity for abnormal refraction eye. Therefore, In this paper, we suggested that the ultrastructure and line structure of Netspeg lens was related to good visual function. However the visual function of the aspheric Netspeg and ultra waterproof Netspeg lens was similar results.

• Investigative Magnetic Resonance Imaging
• /
• v.17 no.2
• /
• pp.73-82
• /
• 2013

Purpose : To determine the quantitative parameters of breast MRI that predict tumor invasion in biopsy-proven DCIS. Materials and Methods: From January 2009 to March 2010, 42 MRI examinations of 41 patients with biopsy-proven DCIS were included. The quantitative parameters, which include the initial percentage enhancement ($E_1$), peak percentage enhancement ($E_{peak}$), time to peak enhancement (TTP), signal enhancement ratio (SER), arterial enhancement fraction (AEF), apparent diffusion coefficient (ADC) value, long diameter and the volume of the lesion, were calculated as parameters that might predict invasion. Univariate and multivariate analyses were used to identify the parameters associated with invasion. Results: Out of 42 lesions, 23 lesions were confirmed to be invasive ductal carcinoma (IDC) and 19 lesions were confirmed to be pure DCIS. Tumor size (p = 0.003; $6.5{\pm}3.2$ cm vs. $3.6{\pm}2.6$ cm, respectively) and SER (p = 0.036; $1.1{\pm}0.3$ vs. $0.9{\pm}0.3$, respectively) showed statistically significant high in IDC. In contrast, E1, Epeak, TTP, ADC, AEF and volume of the lesion were not statistically significant. Tumor size and SER had statistically significant associations with invasion, with an odds ratio of 1.04 and 22.93, respectively. Conclusion: Of quantitative parameters analyzed, SER and the long diameter of the lesion could be specific parameter for predicting invasion in the biopsy-proven DCIS.

• Journal of radiological science and technology
• /
• v.35 no.1
• /
• pp.45-50
• /
• 2012

Nowadays, most of the hospital serves "one stop service" for CT scan. The patients could be taken the CT scan in the day they register for scan. On the contrary to the time convenience, patients are not satisfied with long waiting time and unkindness of staff. The objective of this study is to improve the patient's satisfaction for the CT scan, by analyzing inconvenience factors and improving the service qualities. From April 1 to August 30 in 2011, we investigated the satisfaction of patients who did examined abdomen CT scan with contrast media. We analyzed the 89 questionnaires before and after the service improvements from them. The worker's kindness, the environment of CT room and understanding about CT scan were answered by questionnaire and the waiting time of a day CT scan was drawn by medical information statistics. Also, the period before improvement was from April to June and the period after improvement was from July to September. And these questionnaire was analyzed through SPSS V. 15.0. In this study, kindness of staff, environment of CT room, intelligibility for CT scan and waiting time was explored and analyzed by SPSS V.15.0. The score of kindness was improved by 32%, satisfaction level of the environment was improved by 52.54%. The understanding level about CT scan was improved by 52.36% and the wating time of a day CT was shortened by 21% through our service enhancement programs. Consequentially, it is considered that these efforts would contribute to increase the revenue of hospital.

• Journal of dental hygiene science
• /
• v.9 no.3
• /
• pp.327-338
• /
• 2009

This study was to develop an instrument for multidimensional measurement of Korean scaling fear (KSF)-1.0 and analyze related factors. A sample of 720 subjects(scaling patients and community people) was studied in Daegu city from November in 2008 to March in 2009. Authors first conceptualized the KSF, item generation, item reduction, and questionnaire formatting were performed in the stage of the development. Item descriptive, missing%, item internal consistency, and item discriminant validity were analyzed in the item-level, also descriptive, floor and ceiling effect were analyzed in the scale-level. Cronbach's alpha, test-retest, inter-dimension correlations, and factor analysis were performed to evaluate the validity and reliability in the new instrument. Confirmative factor analysis was did to evaluate the fit of model. The results for item-level and scale-level were acceptable except item discriminant validity. The reliability for 0.92~0.96 of corelation coefficient range(Cronbach's alpha 0.96~0.98) was high in the test-retest, and there was no significant difference in paired t-test. Item internal consistency(range of pearson corelation coefficient 0.39~0.95) was also high. The result of explanatory factor analysis was the same as the intended dimension structure, also confirmatory factor analysis results revealed that the dimensional structure model were fined well in the evaluation of model fit($x^2$= 1245.66, df=146, p=0.0000; GFI=0.85; AGFI=0.80; RMSEA=0.10). Factors related to KSF by multiple regression were gender($\beta$=0.28, p=0.0004) and teeth brush method($\beta$=-0.15, p=0.0053) in scaling patients, also gender($\beta$=0.25, p=0.0002), educational level($\beta$=0.14, p=0.0155), teeth brush method($\beta$=-0.09, p=0.0229) and time of daily work out($\beta$=-0.10, p=0.0055) were significantly associated with KSF in no scaling group. In conclusion, The results of this study reveal that the new developed measurement scale was reliable and val id instrument for measuring the KSF in dental hygiene patients and community people. We recommend that further research should develop more the instrument for the Korean scaling fear.

• Journal of dental hygiene science
• /
• v.9 no.3
• /
• pp.353-360
• /
• 2009

The purpose of this study was to investigate the recognition for improvement of the Korean Dental Hygienists' Licensing Examination(KDHLE). The subjects were 1,048 dental hygienists were surveyed. either in person or through mail. Data was collected using a self administrated questionnaire from July 1 to July 20, 2008. The data were analysed with frequency and $x^2$-test using the SPSS 15.0 windows. For the inquiry where adequacy of subjects of the KDHLE regarding to evaluation of standard duty achievement ability in the real field was asked, 404(39.5%) answered 'Yes', and 680(66.9%) was answered 'Yes' for necessity of changing current subjects of the KDHLE. For the inquiry about the number of questions in the KDHLE, 353(34.6%) answered that current number of questions is 'Inappropriate' and advisable way of improving KDHLE subjects, 463 (45.4%) answered 'enhancing problem solving ability through unifying subjects', the highest of all. About practical examination methods, 647(67.3%) was answered 'Should be modified'. For methods of dental hygienist practical examination, 'clinical demonstration on patients' received the highest number of votes 628(63.6%). According to the above results, most of active dental hygienists at presence expect the alteration of current KDHLE and new items which are reliable for globalization by testing problem solving ability through unified subjects must be introduced.

• Journal of Intelligence and Information Systems
• /
• v.23 no.1
• /
• pp.127-141
• /
• 2017

Advances in Internet technologies and the proliferation of mobile devices enabled consumers to approach a wide range of goods and services, while causing an adverse effect that they have hard time reaching their congenial items even if they devote much time to searching for them. Accordingly, businesses are using the recommender systems to provide tools for consumers to find the desired items more easily. Association Rule Mining (ARM) technology is advantageous to recommender systems in that ARM provides intuitive form of a rule with interestingness measures (support, confidence, and lift) describing the relationship between items. Given an item, its relevant items can be distinguished with the help of the measures that show the strength of relationship between items. Based on the strength, the most pertinent items can be chosen among other items and exposed to a given item's web page. However, the diversity of the measures may confuse which items are more recommendable. Given two rules, for example, one rule's support and confidence may not be concurrently superior to the other rule's. Such discrepancy of the measures in distinguishing one rule's superiority from other rules may cause difficulty in selecting proper items for recommendation. In addition, in an online environment where a web page or mobile screen can provide a limited number of recommendations that attract consumer interest, the prudent selection of items to be included in the list of recommendations is very important. The exposure of items of little interest may lead consumers to ignore the recommendations. Then, such consumers will possibly not pay attention to other forms of marketing activities. Therefore, the measures should be aligned with the probability of consumer's acceptance of recommendations. For this reason, this study proposes a model-based approach to combine those measures into one unified measure that can consistently determine the ranking of recommended items. A regression model was designed to describe how well the measures (independent variables; i.e., support, confidence, and lift) explain consumer's acceptance of recommendations (dependent variables, hit rate of recommended items). The model is intuitive to understand and easy to use in that the equation consists of the commonly used measures for ARM and can be used in the estimation of hit rates. The experiment using transaction data from one of the Korea's largest online shopping malls was conducted to show that the proposed model can improve the hit rates of recommendations. From the top of the list to 13th place, recommended items in the higher rakings from the proposed model show the higher hit rates than those from the competitive model's. The result shows that the proposed model's performance is superior to the competitive model's in online recommendation environment. In a web page, consumers are provided around ten recommendations with which the proposed model outperforms. Moreover, a mobile device cannot expose many items simultaneously due to its limited screen size. Therefore, the result shows that the newly devised recommendation technique is suitable for the mobile recommender systems. While this study has been conducted to cover the cross-selling in online shopping malls that handle merchandise, the proposed method can be expected to be applied in various situations under which association rules apply. For example, this model can be applied to medical diagnostic systems that predict candidate diseases from a patient's symptoms. To increase the efficiency of the model, additional variables will need to be considered for the elaboration of the model in future studies. For example, price can be a good candidate for an explanatory variable because it has a major impact on consumer purchase decisions. If the prices of recommended items are much higher than the items in which a consumer is interested, the consumer may hesitate to accept the recommendations.