• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.18-24
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• 2013

Purpose: Myocardial perfusion SPECT using $^{201}Tl$ is an important method for viability of left ventricle and quantitative evaluation of cardiac function and now various reconstruction methods are used to improve the image quality. But in case of small sized heart, you should always be careful because of the Partial Volume Effect which may cause errors of quantitative indices at the reconstruction step. So, In this study, we compared those quantitative indices of left ventricle according to the reconstruction method of myocardial perfusion SPECT with the Echocardiography and verified the degree of the differences between them. Materials and Methods: Based on ESV 30 mL of Echocardiography, we divided 278 patients (male;98, female;188, Mean age;$65.5{\pm}11.1$) who visited the Asan medical center from February to September, 2012 into two categories; below the criteria to small sized heart, otherwise, normal or large sized heart. Filtered and output each case, we applied the method of FBP and OSEM to each of them, and calculated EDV, ESV and LVEF, and we conducted statistical processing through Repeated Measures ANOVA with indices that measured in Echocardiography. Results: In case of men and women, there were no significant difference in EDV between FBP and OSEM (p=0.053, p=0.098), but in case of Echocardiography, there were meaningful differences (p<0.001). The change of ESV especially women in small sized heard, significant differences has occurred among FBP, OSEM and Echocardiography. Also, in LVEF, there were no difference in men and women who have normal sized heart among FBP, OSEM and Echocardiography (p=0.375, p=0.969), but the women with small sized heart have showed significant differences (p<0.001). Conclusion: The change in quantitative indices of left ventricle between Nuclear cardiology image reconstruction, no difference has occurred in the patients with normal sized heart but based on ESV, under 30 mL of small sized heart, especially in female, there were significant differences in FBP, OSEM and Echocardiography. We found out that overestimated LVEF caused by PVE can be reduced in average by applying OSEM to all kinds of gamma camera, which are used in analyzing the differences.

• Journal of Elementary Mathematics Education in Korea
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• v.9 no.2
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• pp.85-110
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• 2005

The purpose of this study is to examine the characteristics of visual representation used in problem solving process and examine the representation types the students used to successfully solve the problem and focus on systematizing the visual representation method using the condition students suggest in the problems. To achieve the goal of this study, following questions have been raised. (1) what characteristic does the representation the elementary school students used in the process of solving a math problem possess? (2) what types of representation did students use in order to successfully solve elementary math problem? 240 4th graders attending J Elementary School located in Seoul participated in this study. Qualitative methodology was used for data analysis, and the analysis suggested representation method the students use in problem solving process and then suggested the representation that can successfully solve five different problems. The results of the study as follow. First, the students are not familiar with representing with various methods in the problem solving process. Students tend to solve the problem using equations rather than drawing a diagram when they can not find a word that gives a hint to draw a diagram. The method students used to restate the problem was mostly rewriting the problem, and they could not utilize a table that is essential in solving the problem. Thus, various errors were found. Students did not simplify the complicated problem to find the pattern to solve the problem. Second, the image and strategy created as the problem was read and the affected greatly in solving the problem. The first image created as the problem was read made students to draw different diagram and make them choose different strategies. The study showed the importance of first image by most of the students who do not pass the trial and error step and use the strategy they chose first. Third, the students who successfully solved the problems do not solely depend on the equation but put them in the form which information are decoded. They do not write difficult equation that they can not solve, but put them into a simplified equation that know to solve the problem. On fraction problems, they draw a diagram to solve the problem without calculation, Fourth, the students who. successfully solved the problem drew clear diagram that can be understood with intuition. By representing visually, unnecessary information were omitted and used simple image were drawn using symbol or lines, and to clarify the relationship between the information, numeric explanation was added. In addition, they restricted use of complicated motion line and dividing line, proper noun in the word problems were not changed into abbreviation or symbols to clearly restate the problem. Adding additional information was useful source in solving the problem.

• Restorative Dentistry and Endodontics
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• v.23 no.2
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• pp.537-549
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• 1998

The purpose of this study was to evaluate the influence of root resection and retrograde cavity preparation methods on the apical leakage in endodontic surgery. To investigate the effect of various root resection and retrograde cavity preparation methods on the apical leakage, 71 roots of extracted human maxillary anterior teeth and 44 mesiobuccal roots of extracted human maxillary first molars were used. Root canals of the all the specimens were prepared with step-back technique and filled with gutta-percha by lateral condensation method. Three millimeters of each root was resected at a 45 degree angle or perpendicular to the long axis of the tooth according to the groups. Retrograde cavities were prepared with ultrasonic instruments or a slow-speed round bur, and occlusal access cavities were filled with zinc oxide eugenol cement. Three coats of clear nail polish were placed on the lateral and coronal surfaces of the specimens except the apical cut one millimeter. All the specimens were immerged in 2% methylene blue solution for 7 days in an incubator at $37^{\circ}C$. The teeth were dissolved in 14 ml of 35% nitric acid solution and the dye present within the root canal system was returned to solution. The leakage of dye was quantitatively measured via spectrophotometric method. The obtained data were analysed statistically using two-way ANOVA and Duncans Multiple Range Test. The results were as follows: 1. No statistically significant difference was observed between ultrasonic retrograde cavity preparation method and slow-speed round bur technique, without apical bevel (p>0.05). 2. Ultrasonic retrograde preparation method showed significantly less apical leakage than slow-speed round bur technique, with bevel (p<0.0001). 3. No statistically significant difference was found between beveled resected root surface and non-beveled resected root surface, with ultrasonic technique (p>0.05). 4. Non-beveled resected root surface showed significantly less apical leakage than beveled resected root surface, with slow-speed round bur technique (p<0.0001). 5. No statistically significant difference in apical leakage was found between the group of retrograde cavity prepared parallel to the long axis of the tooth and the group of one prepared perpendicular to the long axis of the tooth (p>0.05). 6. Regarding isthmus preparation, ultrasonic retrograde preparation method showed significantly less apical leakage than slow-speed round bur technique, in the mesiobuccal root of maxillary molar, without bevel (p<0.0001).

• Journal of the Korean Electrochemical Society
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• v.26 no.1
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• pp.1-10
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• 2023

The cathode, which is one of the four major components of a lithium secondary battery, is an important component responsible for the energy density of the battery. The mixing process of active material, conductive material, and polymer binder is very essential in the commonly used wet manufacturing process of the cathode. However, in the case of mixing conditions of the cathode, since there is no systematic method, in most cases, differences in performance occur depending on the manufacturer. Therefore, LiMn₂O₄ (LMO) cathodes were prepared using a commonly used THINKY mixer and homogenizer to optimize the mixing method in the cathode slurry preparation step, and their characteristics were compared. Each mixing condition was performed at 2000 RPM and 7 min, and to determine only the difference in the mixing method during the manufacture of the cathode other experiment conditions (mixing time, material input order, etc.) were kept constant. Among the manufactured THINKY mixer LMO (TLMO) and homogenizer LMO (HLMO), HLMO has more uniform particle dispersion than TLMO, and thus shows higher adhesive strength. Also, the result of the electrochemical evaluation reveals that HLMO cathode showed improved performance with a more stable life cycle compared to TLMO. The initial discharge capacity retention rate of HLMO at 69 cycles was 88%, which is about 4.4 times higher than that of TLMO, and in the case of rate capability, HLMO exhibited a better capacity retention even at high C-rates of 10, 15, and 20 C and the capacity recovery at 1 C was higher than that of TLMO. It's postulated that the use of a homogenizer improves the characteristics of the slurry containing the active material, the conductive material, and the polymer binder creating an electrically conductive network formed by uniformly dispersing the conductive material suppressing its strong electrostatic properties thus avoiding aggregation. As a result, surface contact between the active material and the conductive material increases, electrons move more smoothly, changes in lattice volume during charging and discharging are more reversible and contact resistance between the active material and the conductive material is suppressed.

• Journal of Intelligence and Information Systems
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• v.23 no.2
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• pp.39-70
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• 2017

Data-drive analytics techniques have been recently applied to public surveys. Instead of simply gathering survey results or expert opinions to research the preference for a recently launched product, enterprises need a way to collect and analyze various types of online data and then accurately figure out customer preferences. In the main concept of existing data-based survey methods, the sentiment lexicon for a particular domain is first constructed by domain experts who usually judge the positive, neutral, or negative meanings of the frequently used words from the collected text documents. In order to research the preference for a particular product, the existing approach collects (1) review posts, which are related to the product, from several product review web sites; (2) extracts sentences (or phrases) in the collection after the pre-processing step such as stemming and removal of stop words is performed; (3) classifies the polarity (either positive or negative sense) of each sentence (or phrase) based on the sentiment lexicon; and (4) estimates the positive and negative ratios of the product by dividing the total numbers of the positive and negative sentences (or phrases) by the total number of the sentences (or phrases) in the collection. Furthermore, the existing approach automatically finds important sentences (or phrases) including the positive and negative meaning to/against the product. As a motivated example, given a product like Sonata made by Hyundai Motors, customers often want to see the summary note including what positive points are in the 'car design' aspect as well as what negative points are in thesame aspect. They also want to gain more useful information regarding other aspects such as 'car quality', 'car performance', and 'car service.' Such an information will enable customers to make good choice when they attempt to purchase brand-new vehicles. In addition, automobile makers will be able to figure out the preference and positive/negative points for new models on market. In the near future, the weak points of the models will be improved by the sentiment analysis. For this, the existing approach computes the sentiment score of each sentence (or phrase) and then selects top-k sentences (or phrases) with the highest positive and negative scores. However, the existing approach has several shortcomings and is limited to apply to real applications. The main disadvantages of the existing approach is as follows: (1) The main aspects (e.g., car design, quality, performance, and service) to a product (e.g., Hyundai Sonata) are not considered. Through the sentiment analysis without considering aspects, as a result, the summary note including the positive and negative ratios of the product and top-k sentences (or phrases) with the highest sentiment scores in the entire corpus is just reported to customers and car makers. This approach is not enough and main aspects of the target product need to be considered in the sentiment analysis. (2) In general, since the same word has different meanings across different domains, the sentiment lexicon which is proper to each domain needs to be constructed. The efficient way to construct the sentiment lexicon per domain is required because the sentiment lexicon construction is labor intensive and time consuming. To address the above problems, in this article, we propose a novel product reputation mining algorithm that (1) extracts topics hidden in review documents written by customers; (2) mines main aspects based on the extracted topics; (3) measures the positive and negative ratios of the product using the aspects; and (4) presents the digest in which a few important sentences with the positive and negative meanings are listed in each aspect. Unlike the existing approach, using hidden topics makes experts construct the sentimental lexicon easily and quickly. Furthermore, reinforcing topic semantics, we can improve the accuracy of the product reputation mining algorithms more largely than that of the existing approach. In the experiments, we collected large review documents to the domestic vehicles such as K5, SM5, and Avante; measured the positive and negative ratios of the three cars; showed top-k positive and negative summaries per aspect; and conducted statistical analysis. Our experimental results clearly show the effectiveness of the proposed method, compared with the existing method.

• Journal of radiological science and technology
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• v.31 no.4
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• pp.337-346
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• 2008

A questionaire survey was conducted for patients who had been examined at the Department of Radiology to investigate the items that need to be improved. Brainstorming was also conducted by team members to suggest the tactics that can efficiently perform the QI activity by selecting the most frequently answered topics for the reduction of waiting time of x-ray examination. From September 2006 to November 2007, number of patients before and after conducting QI was compared for 3 months by each category differentiated by types of detailed causes. A patient case was set as one shooting for one patient. After conducting QI, the waiting cases before conducting QI were evaluated for the method of improvement for 3 month through the QI team discussion and conducted by following the improvement method for the next 1 month and the waiting cases were measured and the difference before and after the QI activity was compared in percentage. 1. When patient waiting cases were compared before and after conducting QI activity against the causes of repetition, it resulted in 3.9% of reduction effect. 2. When patient waiting cases were compared before and after conducting QI activity against the causes for the lack of guiding, it resulted in 1.1% of reduction effect. 3. When patient waiting cases were compared before and after conducting QI activity against the causes of miss-inputting prescription, it resulted in 1.1% of reduction effect. 4. When patient waiting cases were compared before and after conducting QI activity against the causes for emergency patients, patients with acute pain and discomfort patients, it resulted in 12.0% of reduction effect. 5. When patient waiting cases were compared before and after conducting QI activity against the causes for shooting overlapping of outpatients and hospitalized patients, it resulted in 4.7% of reduction effect. There are many factors to reduce the patient waiting cases in radiography. The first step is for radiology department to find these factors through QI, to improve them, which is the reason why the QI team is organized to perform the QI activities.

• Tuberculosis and Respiratory Diseases
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• v.42 no.5
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• pp.703-712
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• 1995

Background: Peripheral blood monocytes are important immune effector cells that play a fundamental role in cellular immunity. In addition to their antigen-presenting and phagocytic activities, monocytes/macrophage produce a vast array of regulatory and chemotactic cytokines. Interleukin-8(IL-8), a potent neutrophil-activating and chemotactic peptide, is produced in large quantities by mononuclear phagocytes and may be an important mediator of local and systemic inflammation. Overexpression by IL-8 of such inflammation may be an important step of tissue injury frequently seen in inflammatory reaction. So it could be hypothesized that the agents which block the production of IL-8 can decrease the inflammatory reaction and tissue injury. To evaluate this, we described the effect of Dexamethasone, $PGE_2$, Indomethacin and Interferon-$\gamma$(IFN-$\gamma$) on IL-8 mRNA and protein expression from LPS-stimulated human peripheral blood monocytes(PBMC). Method: PBMC was isolated from healthy volunteers. To evaluate the effect of Dexamethasone, $PGE_2$ & Indomethacin, these drug were treated for 1 hour before and after LPS stimulation and IFN-$\gamma$ was only treated I hour before the LPS stimulation. Northern blot analysis for IL-8 mRNA and ELISA for immunoreactive IL-8 protein in culture supernatant were performed. We repeated above experiment three times for Northern blot analysis and two times for ELISA and got the same result. Results: 1) Pre- and post-treatment of Dexamethasone suppressed both the LPS stimulated IL-8 mRNA expression and IL-8 protein release in PBMC. 2) IFN-$\gamma$ pre-treatment suppressed the IL-8 mRNA expression and IL-8 protein release in unstimulated cells. 3) In LPS stimulated cells, IFN-$\gamma$ suppressed the IL-8 mRNA expression but IL-8 protein release suppression was not observed. 4) $PGE_2$ and Indomethacin exert no effect on the LPS-stimulated IL-8 mRNA and protein expression in concentration used in this experiment ($PGE_2;10^{-6}M$, Indomethacin; $10{\mu}M$). Conclusion: One of the mechanism of antiinflammatory action of Dexamethasone can be explained by the suppressing effect of IL-8 production in some extent and by this antiinflammatory effect, dexamethasone can be used to suppress local and systemic inflammation mediated by IL-8.

• Journal of Gifted/Talented Education
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• v.10 no.2
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• pp.71-86
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• 2000

According to Torrance, it is said that about 30% of feeble-headed children are bearing potential brilliant quality. Such potential gifted children exist really much more than children who appear to show their own brilliant quality. Nevertheless, research activity to reveal children's potential giftedness has not been relatively actively progressed. Renzulli, Smith and so on progresses research activity to reveal children's potential giftedness and strategies developed by them are being used widely all over the world, but these strategies show the defect that children can not overcome by themselves the interfered factors influenced negatively on their gift revelation. Russian scholar Babaeva made the effective education program to develop children's potential giftedness. Her program includes various activity methods or mental correct activity and psychological training activity and such training activity is realized through some steps and each step has it's own purpose and realization method. With the result that children discriminated as common children by the experimental study which is progressed by the present program participate, their standard of intelligence and originality showed the improved effect of the similar standard to children factors not a little influencing on children's giftedness development process but she also developed the leading concrete study method for the children to overcome this by themselves. In this paper, the present writer will examine potential giftedness development program researched in Russia and discuss their theoretic background and concrete activity course, activity result. Through this, children's have the excellent abilities in various spheres, this writer will obtain significant suggestions to educate the potential gifted children who do not display their own potentialities and do not receive a favor from gifted children program.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.3
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• pp.183-200
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• 2022

This study is a study on the effect of a healing experience program on satisfaction in the field of healing agriculture. In the development of a rural experience program, what factors constituting the healing experience program affect satisfaction, and how much time and participation cost affect the satisfaction of the healing experience program from the marketing point of view of the healing experience program. I want to analyze By researching the effect of experience cost and experience time on satisfaction of the healing experience program, I would like to suggest the development direction of the healing experience program. To this end, by empirically analyzing the effect of a healing experience program using experience cost and experience time as parameters on satisfaction, we present a theoretical basis for priority considerations when developing a rural experience program. There are entertainment experience, educational experience, deviant experience, and aesthetic experience as sub-factors of the experience program, experience time and experience cost as parameters, and satisfaction as a dependent variable. In addition, the reliability of the research results was secured by setting the demographic variables of the survey subjects as control variables. The empirical analysis was conducted on 314 valid questionnaires from the unspecified majority who were interested in or aware of the healing experience program. SPSS v22.0 was used, and to test the mediating effect, the three-step verification method of Baron & Kenny(1986) and the SPSS PROCESS Macro Model No. of Andrew F. Hayes(2018). 4 The reliability of the mediating effect was secured by applying the verification method and comparing the analysis resul. As a result of the study, it was found that educational experience (𝛽=.134, t=1.759*) had a positive (+) effect on experience cost, and aesthetic experience (𝛽=.144 t=1.684*) had a positive (+) effect on experience time. +) was found to have an effect. Also, educational experience (𝛽=.239, t=4.112***) was found to have a positive (+) effect on satisfaction, and aesthetic experience (𝛽=.330 t=4.921***) had a positive effect on satisfaction. It has been shown to have a (+) effect. Experience time was found to have a negative (-) inconsistent mediating effect between aesthetic experience and satisfaction. That is, it is the total effect (𝛽=.330 t=4.921***), and the direct effect (𝛽=.349 t=5.241***) increased by 𝛽=.019 compared to the total effect when the experience time was input, while the indirect effect (𝛽=-.019), which was shown to exert a negative (-) mediating effect.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.6 s.312
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• pp.28-35
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• 2006

Statistical models of shape variability based on active shape models (ASMs) have been successfully utilized to perform segmentation and recognition tasks in two-dimensional (2D) images. Three-dimensional (3D) model-based approaches are more promising than 2D approaches since they can bring in more realistic shape constraints for recognizing and delineating the object boundary. For 3D model-based approaches, however, building the 3D shape model from a training set of segmented instances of an object is a major challenge and currently it remains an open problem in building the 3D shape model, one essential step is to generate a point distribution model (PDM). Corresponding landmarks must be selected in all1 training shapes for generating PDM, and manual determination of landmark correspondences is very time-consuming, tedious, and error-prone. In this paper, we propose a novel automatic method for generating 3D statistical shape models. Given a set of training 3D shapes, we generate a 3D model by 1) building the mean shape fro]n the distance transform of the training shapes, 2) utilizing a tetrahedron method for automatically selecting landmarks on the mean shape, and 3) subsequently propagating these landmarks to each training shape via a distance labeling method. In this paper, we investigate the accuracy and compactness of the 3D model for the human liver built from 50 segmented individual CT data sets. The proposed method is very general without such assumptions and can be applied to other data sets.