• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.10-16
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• 2011

Purpose: The partial volume effect occurs because of limit of the spatial resolution. It makes partial loss of intensity and causes SUV to be lower than it should actually be. So the purpose of this study is to calculate recovery coefficient for correcting PVE from phantom study and to compare before and after SUV correction applying to PET/CT examination. Materials and Methods: The flangeless Esser PET phantom consisting of four hot cylinders was used for this study. All of the hot cylinders were filled with FDG solution of 20.72 MBq per 1000 ml, and the phantom background was filled with FDG solution of different concentrations (33.30, 22.20, 16.65 MBq per 6440 ml) to yield H/B ratios of around 4:1, 6:1 and 8:1. Using the Biograph Truepoint 40(SIEMENS, Germany), we applied recovery coefficient method to 30 patients who were diagnosed with lung cancer after PET/CT exam. And then we analyzed and compared SUV before and after correcting partial volume effect. Results: The smaller the diameter of hot cylinder becomes, the more recovery coefficient decreased. When we applied recovery coefficient to clinical patients and compared SUV before and after correcting PVE, before the correction all lesions gave an average max SUV of 7.83. And after the correction, the average max SUV increases to 10.31. The differences in the max SUV between before and after correction were analyzed by paired t test. As a result, there were statistically significant differences (t=7.21, p=0.000). Conclusion: The SUV for quantification should be measured precisely to give consistent information of tumor uptake. But PVE is one of factors that causes SUV to be lower and to be underestimated. We can correct this PVE and calculate corrected SUV using the recovery coefficient from phantom study. And if we apply this correction method to clinical patients, we can finally assess and provide quantitative analysis more accurately.

• Journal of Science Education
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• v.42 no.2
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• pp.106-119
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• 2018

The purposes of this study were to develop a learner activity-centered science class program, apply it to the fourth-grade elementary students, and analyze its effects on their attitude towards science, academic achievement, and concept sustainability. To this end, the content of the fourth-grade elementary subject related to 'volcanoes and earthquakes' was reorganized through 12 periods, and the class was divided into two groups. Then, general science class was applied to the comparative group, and the learner activity-centered science class program including writing, making, and expressing was applied to the experimental group. In order to compare the two groups regarding attitude towards science, academic achievement, and concept sustainability before and after the application, mind map data was collected and analyzed based on mind map grading criteria. As a result of the post-test, the two groups showed statistically significant differences in all the sub-factors of attitude towards science, that is, recognition, ability, value, and interest sustainability, especially in interest sustainability. As for academic achievement, as a result of the post-achievement test, the experimental group had higher average scores than the comparative group, and it also showed improved scores compared to the pre-achievement test results. In addition, as a result of the post-achievement test, both the two groups showed statistically significant results. In the concept sustainability test after the post-achievement test, the experimental group had higher average scores than the comparative group in the areas of center circle, branches, and expression, which were the evaluation criteria for the mind map analysis, and the two groups showed statistically significant differences in the areas of center circle and expression, except for branches. In conclusion, learner activity-centered science class turned out to be effective on students' attitude towards science, academic achievement, and concept sustainability. If the learner activity-centered science class program is actively introduced and used in actual educational sites, it is expected to contribute to improving related classes.

• Journal of Chest Surgery
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• v.41 no.6
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• pp.679-686
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• 2008

Background: Cellular remnants in the bioprosthetic heart valve are known to be related to a host's immunologic response and they can form the nidus for calcification. The extracellular matrix of the decellularized valve tissue can also be used as a biological scaffold for cell attachment, endothelialization and tissue reconstitution. Thus, decellularization is the most important part in making a bioprosthetic valve and biological caffold. Many protocols and agents have been suggested for decellularization, yet there ave been few reports about the effect of a treatment with hypotonic solution prior to chemical or enzymatic treatment. This study investigated the effect of a treatment with hypotonic solution and the appropriate environments such as temperature, the treatment duration and the concentration of sodium dodecylsulfate (SDS) for achieving proper decellularization. Material and Method: Porcine aortic valves were decellularized with odium dodecylsulfate at various concentrations (0.25%, 0.5%), time durations (6, 12, 24 hours) and temperatures ($4^{\circ}C$, $20^{\circ}C$)(Group B). Same the number of porcine aortic valves (group A) was treated with hypotonic solution prior to SDS treatment at the same conditions. The duration of exposure to the hypotonic solution was 4, 7 and 14 hours and he temperature was $4^{\circ}C$ and $20^{\circ}C$, respectively. The degree of decellularization was analyzed by performing hematoxylin and eosin staining. Result: There were no differences in the degree of decellularization between the two concentrations (0.25% 0.5%) of SDS. Twenty four hours treatment with SDS revealed the best decellularization effect for both roups A and B at the temperature of $4^{\circ}C$, but there was no differences between the roups at $20^{\circ}C$. Treatment with hypotonic solution (group A) showed a better ecellularization effect at all the matched conditions. Fourteen hours treatment at $4^{\circ}C$ ith ypotonic solution prior to 80S treatment revealed the best decellularization effect. The treatment with hypotonic solution at $20^{\circ}C$ revealed a good decellularization effect, but his showed significant extracellular matrix destruction. Conclusion: The exposure of porcine heart valves to hypotonic solution prior to SDS treatment is highly effective for achieving decellularization. Osmotic treatment with hypotonic solution should be considered or achieving decellularization of porcine aortic valves. Further study should be carried out to see whether the treatment with hypotonic solution could reduce the exposure duration and concentration of chemical detergents, and also to evaluate how the structure of the extracellular matrix of the porcine valve is affected by the exposure to hypotonic solution.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.4
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• pp.1-10
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• 2019

The purpose of this study is to examine the design ＆ construction methods of the traditional landscape space of the past and the repair and maintenance of cultural heritages to maintain it today. To this end, the method of narrative description, process extraction and construction related to traditional landscaping were compared to each other based on the 『Imwongyeongjeji』 「Seomyongji」 and 'Standard Specification for Repairing Cultural Heritages'. The results are as follows; First, to analyze at the description methods of the 『Imwongyeongjeji』 「Seomyongji」 and 'Standard Specification for Repairing Cultural Heritages' and related processes in the field of traditional landscaping. 『Imwongyeongjeji』 「Seomyongji」 was an encyclopedia of the overall construction method of the living space, describing the location, effect, and advantages and disadvantages of each component and presenting quantitative figures to institutionalize the construction of traditional landscaping spaces. 'Standard Specification for Repairing Cultural Heritages' presented the entire process of repairing cultural heritages, and it is becoming a kind of guide for reference at the site. Among them, foundation construction, roof construction, landscape construction, and fence construction were drawn as items that could be applied to traditional landscaping areas. Second, the traditional landscape space construction method was divided into the processes of foundation construction, roof construction, landscaping construction, and fence construction. Foundation construction is a way of repeating the process of land-tramping. During the construction of the roof, the tile-roofed building was built on top of the rafters and roofed with tiles. And thatched roof was made to a number of rice straws bundles to cover the roof one after the other. Instead of tiles, the stone roof was made of thin and wide stones, and the wooden boards were used for the single roof and the bark roof were constructed with many layers of dried corrugations. Landscape construction mainly consists of the Paving technique through tramping rubble and the construction of terraced flower by planting stone, plants, and shrubs on the top. According to the building materials, the wall construction was derived from the earth-stacked earthen wall, stone walls using stone and clay, marble walls made of tile patterns, and the construction of a board wall using a wood board as a wall. Third, comparing the construction methods of the 『Imwongyeongjeji』 「Seomyongji」 and 'Standard Specification for Repairing Cultural Heritages', 『Imwongyeongjeji』 「Seomyongji」 focuses on standardizing the construction methods to create a new traditional space. There is a difference in the setting of the scope of the 『Imwongyeongjeji』 「Seomyongji」 and the construction because 'Standard Specification for Repairing Cultural Heritages' provides the overall construction procedure considering the diversity of the cultural heritages. In addition, the traditional landscape space used to be a residential space in the past, but today, the maintenance process of the already established facilities as designated cultural heritages has been carried out, and construction methods have been added to create viewing conditions. In terms of the succession of traditional knowledge, some similar methods were found in the repair of cultural assets today, and some cases were also confirmed in the reconstruction of traditional technologies such as application of some materials or mix, separation of added facilities and introduction of efficient construction methods.

• Journal of Korean Home Economics Education Association
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• v.28 no.3
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• pp.1-16
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• 2016

The purpose of this study was to develop and evaluate the teaching-learning process plan of senior cohousing to improve understanding of active and independent living in later life through Home Economics subject. The plan consisting of 5 lessons has been developed and implemented according to the ADDIE model. Various activity materials (28 individual activity sheets, 2 working sheets, and 26 teacher's reading texts) and visual materials (4 sets of pictures & photos and 10 moving pictures) as well as questionnaire were developed for the 5-session lessons. The plans were implemented to 6 classes 150 freshmen of P high school in Jeju-do during August 17th to 3rd of September, 2015. Students were highly satisfied regardless of gender with the whole 5-lessons in the aspects such as the level of participation in the lesson, understanding of the contents, adequacy of materials and activities, and usage in their future life. Students also reported that they highly accomplished the goal of each lesson to reinforce the understanding on necessity of preparing later life, senior cohousing, and senior friendly business. It can be concluded that the teaching learning process plan for senior cohousing would improve understanding and practical competency of active and independent living in later life with senior neighbors through the home economics subject.

• Journal of the Korean earth science society
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• v.23 no.7
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• pp.552-564
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• 2002

The data of satellite-observed Microwave Sounding Unit (MSU) channel 1 (Ch1) brightness temperature and General Circulation Model (GCM) reanalyses over the globe have been used to investigate low tropospheric hydrometeors and microwave surface emissivity during the period from January 1981 to December 1993. The average of GCM Ch1 temperature has been reconstructed from three kinds of reanalyses, based on the MSU weighting function. Since the GCM temperature mainly corresponds to the thermal state of the lower troposphere without the difference in the emissivity between ocean and land, it is higher in summer than in other seasons over the regions. The MSU temperature over the ocean shows its maximum at the ITCZ and the SPCZ due to hydrometeors. Over high latitude ocean, the temperature is enhanced because of sea ice emissivity, while it is reduced over the land. The seasonal displacement of the ITCZ and the SPCZ systematically appeared in the difference of Ch1 temperature between the GCM and the MSU. The difference values decrease in the regions of the ITCZ, the SPCZ, and the sea ice because of the increase of the MSU temperature. According to the local minima of the values, the ITCZ moves norhward to 9 N in fall, and the SPCZ moves southward to 12 S in boreal fall and winter. The sea ice in the northern hemisphere is extended southward to 53 N in winter, while the ice in the southern hemisphere, northward to 58 S in boreal summer. We also have discussed the separated contribution from hydrometeors and surface emissivity to the MSU Ch1 temperature, utilizing radiative transfer theory. The increase of 4-6K in the temperature over the ITCZ is inferred to result from hydrometeors of 1-1.5mm/day, and furthermore the increase of 10-30K over the high latitude ocean, ice emissivity of 0.6-0.9.

• Korean Journal of Construction Engineering and Management
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• v.1 no.2 s.2
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• pp.98-107
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• 2000

Increased use of computers in AEC (Architecture, Engineering and Construction) has expanded the amount of information gained from CAD (Computer Aided Design), PMIS (Project Management Information System), Structural Analysis Program, and Scheduling Program as well as making it more complex. And the productivity of AEC industry is largely dependent on well management and efficient reuse of this information. Accordingly, such trend incited much research and development on ITC (Information Technology in Construction) and CIC (Computer Integrated Construction) to be conducted. In exemplifying such effort, many researchers studied and researched on IFC (Industry Foundation Classes) since its development by IAI (International Alliance for Interoperability) for the product based information sharing. However, in spite of some valuable outputs, these researches are yet in the preliminary stage and deal mainly with conceptual ideas and trial implementations. Research on unveiling the process of the IFC application development, the core of the Design Information management system, and its applicable plan still need be done. Thus, the purpose of this paper is to determine the technologies needed for Design Information management system using IFC, and to present the key roles and the process of the IFC application development and its applicable plan. This system play a role to integrate the architectural information and the structural information into the product model and to group many each product items with various levels and aspects. To make the process model, we defined two activities, 'Product Modeling', 'Application Development', at the initial level. Then we decomposed the Application Development activity into five activities, 'IFC Schema Compile', 'Class Compile', 'Make Project Database Schema', 'Development of Product Frameworker', 'Make Project Database'. These activities are carried out by C++ Compiler, CAD, ObjectStore, ST-Developer, and ST-ObjectStore. Finally, we proposed the applicable process with six stages, '3D Modeling', 'Creation of Product Information', 'Creation and Update of Database', 'Reformation of Model's Structure with Multiple Hierarchies', 'Integration of Drawings and Specifications', and 'Creation of Quantity Information'. The IFCs, including the other classes which are going to be updated and developed newly on the construction, civil/structure, and facility management, will be used by the experts through the internet distribution technologies including CORBA and DCOM.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.1
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• pp.40-47
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• 2006

Purpose: The aim of this study was to examine the effects of attenuation correction (AC) and scatter correction (SC) on the quantification of PET count rates. Materials and Methods: To assess the effects of AC and SC $^{18}F$-FDG PET images of phantom and cat brain were acquired using microPET R4 scanner. Thirty-minute transmission images using $^{68}Ge$ source and emission images after injection of FDG were acquired. PET images were reconstructed using 2D OSEM. AC and SC were applied. Regional count rates were measured using ROIs drawn on cerebral cortex including frontal, parietal, and latral temporal lobes and deep gray matter including head of caudate nucleus, putamen and thalamus for pre- and post-AC and SC images. The count rates were then normalized with the injected dose per body weight. To assess the effects of AC, count ratio of "deep gray matter/cerebral cortex" was calculated. To assess the effects of SC, ROIs were also drawn on the gray matter (GM) and white matter (WM), and contrast between them ((GM-WM)/GM was measured. Results: After the AC, count ratio of "deep gray matter/cerebral cortex" was increased by $17{\pm}7%$. After the SC, contrast was also increased by $12{\pm}3%$. Conclusion: Relative count of deep gray matter and contrast between gray and white matters were increased after AC and SC, suggesting that the AC would be critical for the quantitative analysis of cat brain PET data.

• The Korean Journal of Nuclear Medicine
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• v.32 no.5
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• pp.403-413
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• 1998

Purpose: We investigated reproducibility of the quantification of left ventricular volume and ejection fraction, and grading of myocardial wall motion and systolic thickening when we used gated myocardial SPECT and Cedars quantification software. Materials and Methods: We performed gated myocardial SPECT in 33 consecutive patients twice in the same position after Tc-99m-MIBI SPECT We used 16 frames per cycle for the gating of sequential Tc-99m-MIBI SPECT. After reconstruction, we used Cedars quantitative gated SPECT and calculated ventricular volume and ejection fraction (EF). Wall motion was graded using 5 point score. Wall thickening was graded using 4 point score. Coefficient of variation for re-examination of volume and fraction were calculated. Kappa values (k-value) for assessing reproducibility of wall motion or wall thickening were calculated. Results: Enddiastolic volumes (EDV) ranged from 58 ml to 248 ml (122 ml +/- 42 ml), endsystolic volumes (ESV) from 20 ml to 174 ml (65 ml +/- 39 ml), and EF from 20% to 65% (51% +/- 14%). Geometric mean of standard deviations of 33 patients was 5.0 ml for EDV, 3.9 ml for ESV and 1.9% for EF. Their average differences were not different from zero (p>0.05). k-value for wall motion using 2 consecutive images was 0.76 (confidence interval: 0.71-0.81). k-value was 0.87 (confidence interval: 0.83-0.90) for assessment of wall thickening. Conclusion: We concluded that quantification of functional indices, assessment of wall motion and wall thickening using gated Tc-99m-MIBI SPECT was reproducible and we could use this method for the evaluation of short-acting drug effect.

• The Korean Journal of Nuclear Medicine
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• v.36 no.5
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• pp.288-297
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• 2002

Purpose: Soft tissue attenuation and scattering are major methodological limitations of myocardial perfusion SPECT. To overcome these limitations, algorithms for attenuation, scatter correction and resolution recovery (ASCRR) is being developed, while quantitative myocardial SPECT has also become available. In this study, we investigated the efficacy of an ASCRR-corrected quantitative myocardial SPECT method for the diagnosis of coronary artery disease (CAD). Materials and Methods: Seventy-five patients (M:F=51:24, $61.0{\pm}8.9$ years old) suspected of CAD who underwent coronary angiography (CAG) within $7{\pm}12$ days of SPECT(Group-I) and 20 subjects (M:F=10:10, age $40.6{\pm}9.4$) with a low likelihood of coronary artery disease (Group-II) were enrolled. Tl-201 rest/ dipyridamole-stress Tc-99m-MIBI gated myocardial SPECT was performed. ASCRR correction was peformed using a Gd-153 line source and automatic software (Vantage-Pro; ADAC Labs, USA). Using a 20-segment model, segmental perfusion was automatically quantified on both the ASCRR-corrected and uncorrected images using an automatic quantifying software (AutoQUANT; ADAC Labs.). Using these quantified values, CAD was diagnosed in each of the 3 coronary arterial territories. The diagnostic performance of ASCRR-corrected SPECT was compared with that of non-corrected SPECT. Results: Among the 75 patients of Group-I, 9 patients had normal CAG while the remaining 66 patients had 155 arterial lesions; 61 left anterior descending (LAD), 48 left circumflex (LCX) and 46 right coronary (RCA) arterial lesions. For the LAD and LCX lesions, there was no significant difference in diagnostic performance. In Group-II patients, the overall normalcy rate improved but this improvement was not statistically significant (p=0.07). However, for RCA lesions, specificity improved significantly but sensitivity worsened significantly with ASCRR correction (both p<0.05). Overall accuracy was the same. Conclusion: The ASCRR correction did not improve diagnostic performance significantly although the diagnostic specificity for RCA lesions improved on quantitative myocardial SPECT. The clinical application of the ASC-RR correction requires more discretion regarding cost and efficacy.