• Progress in Medical Physics
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• v.20 no.4
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• pp.208-215
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• 2009

This study is to compare the accuracy of evaluation regarding the volume of the prostate, which three-dimensional volume rendering was produced the shape of protrusion, by measuring two kinds of craniocaudal length from the top of the protrusion and from the exclusion of the protrusion as the starting points. For the imaginary protrusion prostate models, total of 10 models were roughly made by using devils-tongue jelly and changing each of the 10 ml of capacity from 10 ml to 100 ml. For the protrusion prostate models aimed at estimating the real volume, through 64 cannel computed tomography (CT) and 3.0 tesla magnetic resonance image (MRI) were conducted by planimetry technique from three-dimensional volume rendering. And then we performed to evaluate on significance of these volumes by wilcoxon signed rank test. Also the obtained volumes data by ellipsoid volume formula were measured the volume of protrusion prostate models two times with each method using the two kinds of craniocaudal length from top of the protrusion and from exclusion of the protrusion as the starting points. Finally, the significance of differences using wilcoxon signed rank test was evaluated between the real volume by planimetry technique and the measured volume by ellipsoid volume formula from three-dimensional volume rendering. The average of the protrusion length on the models was $0.90{\pm}0.18\;mm$ in CT and was $0.75{\pm}0.11\;mm$ in MRI. There were not statistically significant difference between MRI and CT from the volume of protrusion prostate models (p=0.414). In MRI (p=0.139) and CT (p=0.057), there were not statistically significant difference between the real volume by planimetry technique and the measured volume by ellipsoid volume from exclusion of the protrusion as the starting points. While, there were statistically significant difference between the real volume by planimetry technique and the measured volume by ellipsoid volume from top of the protrusion as the starting points in MRI (p=0.005) and CT (p=0.005). For the accurate measurement of the protrusion prostate models, the craniocaudal length of the prostate should be measured from the exclusion of the protrusion as the starting points.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.38-40
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• 2010

Purpose: This study was performed to find the current problems of PET/CT data from other hospitals. Materials and Methods: The subjects were acquired from 64 hospitals referred to our department for image interpretation. The formats and contents of PET/CT data were reviewed and the phone questionnaire survey about these were performed. Results: PET/CT data from 39 of 64 hospitals (61%) included all transaxial CT and PET images with DICOM (Digital Imaging Communications in Medicine) standard format which were required for authentic interpretation. PET/CT data from the others included only secondary capture images or fusion PET/CT images. Conclusion: The majority of hospitals provided limited PET/CT data which could be inadequate for accurate interpretation and clinical decision making. It is necessary to standardize the format of PET/CT data to transfer including all transaxial CT and PET images with DICOM standard format.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.6
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• pp.307-317
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• 2002

In this paper we propose a new mesh reconstruction scheme that produces a displaced subdivision surface directly from unorganized points. The displaced subdivision surface is a new mesh representation that defines a detailed mesh with a displacement map over a smooth domain surface, but original displaced subdivision surface algorithm needs an explicit polygonal mesh since it is not a mesh reconstruction algorithm but a mesh conversion (remeshing) algorithm. The main idea of our approach is that we sample surface detail from unorganized points without any topological information. For this, we predict a virtual triangular face from unorganized points for each sampling ray from a parameteric domain surface. Direct displaced subdivision surface reconstruction from unorganized points has much importance since the output of this algorithm has several important properties: It has compact mesh representation since most vertices can be represented by only a scalar value. Underlying structure of it is piecewise regular so it ran be easily transformed into a multiresolution mesh. Smoothness after mesh deformation is automatically preserved. We avoid time-consuming global energy optimization by employing the input data dependant mesh smoothing, so we can get a good quality displaced subdivision surface quickly.

• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.34-39
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• 2018

This research was conducted to estimate moisture content in cucurbitaceae seedlings, such as cucumber and watermelon, using hyperspectral imagery. Using a hyperspectral image acquisition system, the reflectance of leaf area of cucumber and watermelon seedlings was calculated after providing water stress. Then, moisture content in each seedling was measured by using a dry oven. Finally, using reflectance and moisture content, the moisture content estimation models were developed by PLSR analysis. After developing the estimation models, performance of the cucumber showed 0.73 of $R^2$, 1.45% of RMSE, and 1.58% of RE. Performance of the watermelon showed 0.66 of $R^2$, 1.06% of RMSE, and 1.14% of RE. The model performed slightly better after removing one sample from cucumber seedlings as outlier and unnecessary. Hence, the performance of new model for cucumber seedlings showed 0.79 of $R^2$, 1.10% of RMSE, and 1.20% of RE. The model performance combined with all samples showed 0.67 of $R^2$, 1.26% of RMSE, and 1.36% of RE. The model of cucumber showed better performance than the model of watermelon. This is because variables of cucumber are consisted of widely distributed variation, and it affected the performance. Further, accuracy and precision of the cucumber model were increased when an insignificant sample was eliminated from the dataset. Finally, it is considered that both models can be significantly used to estimate moisture content, as gradients of trend line are almost same and intersected. It is considered that the accuracy and precision of the estimating models possibly can be improved, if the models are constructed by using variables with widely distributed variation. The improved models will be utilized as the basis for developing low-priced sensors.

• Journal of Astronomy and Space Sciences
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• v.22 no.1
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• pp.1-12
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• 2005

The Korean VLBI Network (KVN) will open a new field of research in astronomy, geodesy and earth science using the newest three Elm radio telescopes. This will expand our ability to look at the Universe in the millimeter regime. Imaging capability of radio interferometry is highly dependent upon the antenna configuration, source size, declination and the shape of target. In this paper, imaging simulations are carried out with the KVN system configuration. Five test images were used which were a point source, multi-point sources, a uniform sphere with two different sizes compared to the synthesis beam of the KVN and a Very Large Array (VLA) image of Cygnus A. The declination for the full time simulation was set as +60 degrees and the observation time range was -6 to +6 hours around transit. Simulations have been done at 22GHz, one of the KVN observation frequency. All these simulations and data reductions have been run with the Astronomical Image Processing System (AIPS) software package. As the KVN array has a resolution of about 6 mas (milli arcsecond) at 220Hz, in case of model source being approximately the beam size or smaller, the ratio of peak intensity over RMS shows about 10000:1 and 5000:1. The other case in which model source is larger than the beam size, this ratio shows very low range of about 115:1 and 34:1. This is due to the lack of short baselines and the small number of antenna. We compare the coordinates of the model images with those of the cleaned images. The result shows mostly perfect correspondence except in the case of the 12mas uniform sphere. Therefore, the main astronomical targets for the KVN will be the compact sources and the KVN will have an excellent performance in the astrometry for these sources.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.432-442
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• 2009

This research had a look at what effect of the pursing benefit has on satisfaction, behavioral intention, and attitude of the visitors to the Gwangju Biennale. The survey was conducted for 320 visitors who finished their exhibition viewing schedule starting September 5 until September 19 [15 days]. 300 questionnaires excepting 20 unfaithfully responded copies among those collected from the surveyed were used for the analysis. As for the statistical disposal of the collected data, after going through the process of Data Coding, this research conducted an frequency analysis using SPSS 12.0 for window & statistics package program AMOS 5.0, an exploratory factor analysis to test the reliability and feasibility of the data, and reliability test of each factor; then, this research tested a hypothesis using structural equation model. The research results are as follows: First, as a result of factor analysis of the 15 pursuing benefits, 4 factors were elicited, such as pursuit of an intellectual experience, pursuit of a novel, exotic experience, pursuit of interpersonal, cultural exchange, and pursuit of internal fullness, etc.; as a result of factor analysis of the 10 attitudes, three factors were elicited, such as affective, cognitive, behavioral factors; as a result of factor analysis of 12 types of satisfaction, two factors, such as satisfaction with facilities and convenience matters, etc. were elicited. Second, as a result of the suitability of research model, suitability, its fidelity came out as $x^2=107.508$, d.f.=48, p=.000, Q=2.240, GFI=.942, AGFI=.906, RMR=.024, NFI=.952, TLI=.963, CFI=.973, RMSEA=.064. Third, pursuing benefit was found out to have a positive effect on satisfaction, attitude, and behavioral intention. Fourth, attitude was found out to have a positive significant effect on satisfaction. Fifth, attitude was found out to have a positive effect on behavioral intention. Sixth, satisfaction was found out to have a positive effect on behavioral intention.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.3
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• pp.154-166
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• 2009

Database query and reporting tools, OLAP tools and data mining tools are typical front-end tools in Business Intelligence environment which is able to support gathering, consolidating and analyzing data produced from business operation activities and provide access to the result to enterprise's users. Traditional reporting tools have an advantage of creating sophisticated dynamic reports including SQL query result sets, which look like documents produced by word processors, and publishing the reports to the Web environment, but data source for the tools is limited to RDBMS. On the other hand, OLAP tools and data mining tools have an advantage of providing powerful information analysis functions on each own way, but built-in visualization components for analysis results are limited to tables or some charts. Thus, this paper presents a system that integrates three typical front-end tools to complement one another for BI environment. Traditional reporting tools only have a query editor for generating SQL statements to bring data from RDBMS. However, the reporting tool presented by this paper can extract data also from OLAP and data mining servers, because editors for OLAP and data mining query requests are added into this tool. Traditional systems produce all documents in the server side. This structure enables reporting tools to avoid repetitive process to generate documents, when many clients intend to access the same dynamic document. But, because this system targets that a few users generate documents for data analysis, this tool generates documents at the client side. Therefore, the tool has a processing mechanism to deal with a number of data despite the limited memory capacity of the report viewer in the client side. Also, this reporting tool has data structure for integrating data from three kinds of data sources into one document. Finally, most of traditional front-end tools for BI are dependent on data source architecture from specific vendor. To overcome the problem, this system uses XMLA that is a protocol based on web service to access to data sources for OLAP and data mining services from various vendors.

• Information Systems Review
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• v.18 no.1
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• pp.157-175
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• 2016

Under the market economy of capitalism, several limitations reveal the inequity and redistribution problem of wealth, inefficiency of over-manufacturing and over-consumption, pollution of the natural environment, and the constraint of human liberty and dignity. The new challenge of symbiotic relationships that encourage individual corporations coincides with the need to practice social responsibility and share values to overcome these limitations. Social economy and the social enterprises that simultaneously pursue the making of corporate private profits and the realization of social values have been suggested and disseminated as alternative social value creators. Furthermore, the concept of a sharing economy, which refers to the sharing of things rather than owning them, is growing traction as a new paradigm of capitalism. However, these efforts of social enterprises have fallen short against the conflicts between private profit and social values. This study deals with the case of a start-up social corporation, "Purun Bike Sharing Inc.," which is based on a regional sharing economy business model about bike rental services that use Information and Communication Technology (ICT). This corporation pursues harmonic management to achieve a balance between private profit and social value. Its corporate mission is to achieve sharing, coexistence, and contribution for public welfare. This mission is a possible idea for use in the local community network as a core key for sustainable social enterprises. The model can also be an alternative approach to overcome the structural friction in the social corporation. This study considers the case of Purun Bike Sharing as a sustainable way to practice a sharing economy business model based on a regional cooperation network, which can be combined with social value, and to apply ICT to a sharing economy system. It also examines the definition and current state of social enterprises and the sharing economy, and the cases of the sharing economy business model for the review of prior research.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.401-407
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• 2011

The purpose of this study is to know the differences of MR spectra, obtained from normal volunteers by variable TE value, through the quantitative analysis of brain metabolites by peak integral and SNR between 1.5T and 3.0T, together with PRESS and STEAM pulse sequence. Single-voxel MR proton spectra of the human brain obtained from normal volunteers at both 3.0T MR system (Magnetom Trio, SIEMENS, Germany) and 1.5T MR system (Signa Twinspeed, GE, USA) using the STEAM and PRESS pulse sequence. 10 healthy volunteers (3.0T:3 males, 2 females; 1.5T : 3 males, 2 females) with the range from 22 to 30 years old (mean 26 years) participated in our study. They had no personal or familial history of neurological diseases and had a normal neurological examination. Data acquisition parameters were closely matched between the two field strengths. Spectra were recorded in the white matter of the occipital lobe. Spectra were compared in terms of resolution and signal-to-noise ratio(SNR), and echo time(TE) were estimated at both field strengths. Imaging parameters was used for acquisition of the proton spectrum were as follow : TR 2000msec, TE 30ms, 40ms, 50ms, 60ms, 90ms, 144ms, 288ms, NA=96, VOI=$20{\times}20{\times}20mm3$. As the echo times were increased, the spectra obtained from 3.0T and 1.5T show decreased peak integral and SNR at both pulse sequence. PRESS pulse sequence shows higher SNR and signal intensity than those of STEAM. Especially, Spectra in normal volunteers at 3.0T demonstrated significantly improved overall SNR and spectral resolution compared to 1.5T(Fig1). The spectra acquired at short echo time, 3T MR system shows a twice improvement in SNR compared to 1.5T MR system(Table. 1). But, there was no significant difference between 3.0Tand 1.5T at long TE It is concluded that PRESS and short TE is useful for quantification of the brain metabolites at 3.0T MRS, our standardized protocol for quantification of the brain metabolites at 3.0T MRS is useful to evaluate the brain diseases by monitoring the systematic changes of biochemical metabolites concentration in vivo.

• Journal of Periodontal and Implant Science
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• v.37 no.sup2
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• pp.385-396
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• 2007

This study proposed a new classification system for maxillary anterior alveolar ridge deformities based on CAT-scan implant simulation as a useful concept in order to more precisely predict treatment outcomes and the necessity for ridge augmentation prior to implant placement. The results indicate that a high number of cases in the maxillary anterior area would require augmentation procedures in order to achieve ideal implant placement and restoration.