• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.259-267
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• 2004

Purpose: NEMA NU2-2001 was proposed as a new standard for performance evaluation of whole body PET scanners. in this study, system performance of Siemens CTI ECAT EXACT 47 PET scanner including spatial resolution, sensitivity, scatter fraction, and count rate performance in 2D and 3D mode was evaluated using this new standard method. Methods: ECAT EXACT 47 is a BGO crystal based PET scanner and covers an axial field of view (FOV) of 16.2 cm. Retractable septa allow 2D and 3D data acquisition. All the PET data were acquired according to the NEMA NU2-2001 protocols (coincidence window: 12 ns, energy window: $250{\sim}650$ keV). For the spatial resolution measurement, F-18 point source was placed at the center of the axial FOV((a) x=0, and y=1, (b)x=0, and y=10, (c)x=70, and y=0cm) and a position one fourth of the axial FOV from the center ((a) x=0, and y=1, (b)x=0, and y=10, (c)x=10, and y=0cm). In this case, x and y are transaxial horizontal and vertical, and z is the scanner's axial direction. Images were reconstructed using FBP with ramp filter without any post processing. To measure the system sensitivity, NEMA sensitivity phantom filled with F-18 solution and surrounded by $1{\sim}5$ aluminum sleeves were scanned at the center of transaxial FOV and 10 cm offset from the center. Attenuation free values of sensitivity wire estimated by extrapolating data to the zero wall thickness. NEMA scatter phantom with length of 70 cm was filled with F-18 or C-11solution (2D: 2,900 MBq, 3D: 407 MBq), and coincidence count rates wire measured for 7 half-lives to obtain noise equivalent count rate (MECR) and scatter fraction. We confirmed that dead time loss of the last flame were below 1%. Scatter fraction was estimated by averaging the true to background (staffer+random) ratios of last 3 frames in which the fractions of random rate art negligibly small. Results: Axial and transverse resolutions at 1cm offset from the center were 0.62 and 0.66 cm (FBP in 2D and 3D), and 0.67 and 0.69 cm (FBP in 2D and 3D). Axial, transverse radial, and transverse tangential resolutions at 10cm offset from the center were 0.72 and 0.68 cm (FBP in 2D and 3D), 0.63 and 0.66 cm (FBP in 2D and 3D), and 0.72 and 0.66 cm (FBP in 2D and 3D). Sensitivity values were 708.6 (2D), 2931.3 (3D) counts/sec/MBq at the center and 728.7 (2D, 3398.2 (3D) counts/sec/MBq at 10 cm offset from the center. Scatter fractions were 0.19 (2D) and 0.49 (3D). Peak true count rate and NECR were 64.0 kcps at 40.1 kBq/mL and 49.6 kcps at 40.1 kBq/mL in 2D and 53.7 kcps at 4.76 kBq/mL and 26.4 kcps at 4.47 kBq/mL in 3D. Conclusion: Information about the performance of CTI ECAT EXACT 47 PET scanner reported in this study will be useful for the quantitative analysis of data and determination of optimal image acquisition protocols using this widely used scanner for clinical and research purposes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1856-1864
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• 2015

The purpose of this study was to investigate the nutrient intake status of university students in Chuncheon area (175 males and 131 females). This study was conducted by employing a self-administered questionnaire. Dietary assessment was measured by a 24-h recall method. The average height and weight of male students were $175.2{\pm}6.2cm$ and $68.2{\pm}9.9kg$, respectively. For female students, average values were $161.7{\pm}5.2cm$ and $55.1{\pm}6.5kg$, respectively. The mean BMIs for both male and female students were 22.2 and 21.1, respectively. In both male and female students, the rate of skipping breakfast was high. Daily averages for energy, carbohydrates, protein, and fat intakes in male students were significantly higher than those of female students (P<0.001). For male students, protein, vitamin B1, P, Fe, and Na were above recommended nutrient intake and adequate intake, whereas for female students, they were protein, vitamin A, P, and Na. For male students, nutrient intakes for Ca, vitamin $B_2$, vitamin C, and vitamin $B_6$ were below the estimated average requirement (EAR) by at least 50% or more, whereas for female students, they were vitamin C, Fe, vitamin $B_6$, vitamin $B_2$, niacin, folate, and Ca. Ca was alarmingly low, with more than 75% of both male and female students showing levels below the EAR. Therefore, it is important that nutritional education be facilitated for college students to take responsibility of their own health through learning about nutrient intake as well as developing positive eating habits.

• Radiation Oncology Journal
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• v.15 no.4
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• pp.379-385
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• 1997

Purpose : Ovarian dysgerminoma is a highly radiosensitive malignant tumor occurring in young age group. The conventional treatment was total abdominal hysterectomy and bilateral salpingo-oophorectomy followed by radiotherapy. We retrospectively analyzed the treatment results of Patients who had received radiotherapy in the era before chemotherapy was widely used. Material and Method : Twenty two patients with ovarian dysgerminoma were treated at the Department of Therapeutic Radiology, Seoul National University Hospital between August, 1980 and May, 1991. Four patients were excluded from this study, because three patients received incomplete treatment and one received combined chemotherapy. Sixteen patients received postoperative radiotherapy and two patients had radical radiotherapy as tumor was unresectable. Median follow-up period was 99 months (range, 51-178) Median age was 22 years (range, 11-42). Among the postoperatively treated patients, three Patients were in stage IA, eight in stage IC, two in stage II, and three in stage III. One patient had Turner's syndrome. Radiotherapy was performed with high energy photon (telecobalt unit or linear accelerator, either 6MV or 10MV), The radiation dose to the whole abdomen was 1950-2100cGy (median, 2000) and 1050-2520cGy was added to the whole pelvis, the total dose to the whole pelvis was 3000-4500cGy (median, 3500). Prophylactic Paraaortic area irradiation was done in six Patients (dose range, 900-1500cGy). One patient who had positive Paraaortic node, received radiation dose of 1620cGy, followed by additional 900cGy to the gross mass with shrinking field. Total dose to the paraaortic node was 4470cGy. Six patients, including one who had paraaortic node metastasis, received Prophylactic irradiation to mediastinum and supraclavicular area (2520cGy). Of the two patients with unresectable tumors who received radical radiotherapy, one was in stage III and the other was in stage IV with left supraclavicular lymph node metastasis. The stage III patient received radiation to the whole abdomen (2000cGy), followed by boost to whole pelvis (2070cGy) and paraaortic area (2450cGy). Stage IV patient received radiation to the whole abdomen (2000cGy), followed by radiation to the whole pelvis and paraaortic area (2400cGy), mediastinum (2520cGy) , and left supraclavicular area (3550cGy) .Results : The 5 year local control rate was $100\%$ in patients who received postoperative adiuvant radiotherapy after total abdominal hysterectomy and bilateral salpingo-oophorectomy. Only one patient in stage III who did not receive prophylactic irradiation to mediastinum developed mediastinal metastasis. but was salvaged by chemotherapy. So. the 5 year overall survival rate uras also $100\%$. Two patients who received radiation only, are alive without disease at 112 and 155 months. Conclusion : Postoperntive adjuvant radiotherapy as well as radical radiotherapy in unresectable ovarian dysgerminoma was very effective. aut chemotherapy is also an effective treatment modality We now recomrneifd chemotherapy for Patients who need to save their ovarian functien and reserve radiotherapv fov chemo-resistant tumor or recurrence alter che motherapy.

• Journal of Intelligence and Information Systems
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• v.26 no.4
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• pp.149-171
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• 2020

The period at university is to make decision about getting an actual job. As our society develops rapidly and highly, jobs are diversified, subdivided, and specialized, and students' job preparation period is also getting longer and longer. This study analyzed the log data of college students to see how the various activities that college students experience inside and outside of school might have influences on employment. For this experiment, students' various activities were systematically classified, recorded as an activity data and were divided into six core competencies (Job reinforcement competency, Leadership & teamwork competency, Globalization competency, Organizational commitment competency, Job exploration competency, and Autonomous implementation competency). The effect of the six competency levels on the employment status (employed group, unemployed group) was analyzed. As a result of the analysis, it was confirmed that the difference in level between the employed group and the unemployed group was significant for all of the six competencies, so it was possible to infer that the activities at the school are significant for employment. Next, in order to analyze the impact of the six competencies on the qualitative performance of employment, we had ANOVA analysis after dividing the each competency level into 2 groups (low and high group), and creating 6 groups by the range of first annual salary. Students with high levels of globalization capability, job search capability, and autonomous implementation capability were also found to belong to a higher annual salary group. The theoretical contributions of this study are as follows. First, it connects the competencies that can be extracted from the school experience with the competencies in the Human Resource Management field and adds job search competencies and autonomous implementation competencies which are required for university students to have their own successful career & life. Second, we have conducted this analysis with the competency data measured form actual activity and result data collected from the interview and research. Third, it analyzed not only quantitative performance (employment rate) but also qualitative performance (annual salary level). The practical use of this study is as follows. First, it can be a guide when establishing career development plans for college students. It is necessary to prepare for a job that can express one's strengths based on an analysis of the world of work and job, rather than having a no-strategy, unbalanced, or accumulating excessive specifications competition. Second, the person in charge of experience design for college students, at an organizations such as schools, businesses, local governments, and governments, can refer to the six competencies suggested in this study to for the user-useful experiences design that may motivate more participation. By doing so, one event may bring mutual benefits for both event designers and students. Third, in the era of digital transformation, the government's policy manager who envisions the balanced development of the country can make a policy in the direction of achieving the curiosity and energy of college students together with the balanced development of the country. A lot of manpower is required to start up novel platform services that have not existed before or to digitize existing analog products, services and corporate culture. The activities of current digital-generation-college-students are not only catalysts in all industries, but also for very benefit and necessary for college students by themselves for their own successful career development.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.684-689
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• 2012

Poly(acrylic acid) (PAA) microspheres is one of the widely-used polymeric materials for the bio-field application and the electric materials. For the synthesis of PAA microspheres, the polymerization technique using surfactants is applied. After the synthesis, the purification and separation processes are required for the removal of surfactant. When general organic solvents were used, many problems, such as huge amount of waste solvent, additional separation processes, and the possibility of residual media, were occurred. Thus, High-pressure Soxhlet extraction using liquid $CO_2$ was developed to solve these problems. In this study, High-pressure Soxhlet extraction of the synthesized PAA microspheres using liquid $CO_2$ was conducted for the removal of Monasil PCA which is used for the dispersion polymerization of acrylic acid in compressed liquid Dimethyl ether (DME). The morphology of the extracted PAA particles was checked by field emission scanning electron microscopy (FE-SEM) and the residual concentration of Monasil PCA was analyzed by inductively coupled plasma - Optical Emission Spectrometer (ICP-OES). For studying the effect of the solvent effect, Soxhlet extraction was conducted using n-hexane, liquid DME, and liquid $CO_2$. In case of n-hexane, some extracted PAA microspheres were produced. However, deformation was also occurred due to the high thermal energy of n-hexane vapor. Liquid DME could not remove Monasil PCA. When using liquid $CO_2$, the extracted PAA microspheres which were free for the residual solvent were produced without deformation. For finding the optimum operating condition, high-pressure Soxhlet extraction was conducted for 8 hours with changing the temperature of reboiler and condenser. When the extractor temperature is $19.6{\pm}0.2^{\circ}C$ and the pressure is $51.5{\pm}0.5$ bar, the best removal efficiency was obtained.

• Journal of Life Science
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• v.22 no.2
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• pp.209-219
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• 2012

The properties of lactate dehydrogenase (LDH, EC 1.1.1.27) eye-specific $C_4$ isozyme were studied by polyacrylamide gel electrophoresis, Western blotting, immunoprecipitation, and enzyme kinetics. Furthermore, we proposed the optimal conditions for measuring the activity of LDH eye-specific $C_4$ isozyme. The isozymes were detected in the cytosol of eye tissues from Lepomis macrochirus and Micropterus salmoides and were more similar to the $A_4$ than the $B_4$ isozyme. LDH/CS in the eye tissue of L. macrochirus was increased in September, so the ratio of anaerobic metabolism was high. The electrophoretic patterns of mitochondrial LDH were similar to those of cytosolic LDH in the eye tissues of L. macrochirus and Micropterus salmoides. LDH eye-specific $C_4$ isozyme from eye tissue was purified by preparative native-PAGE. The activities of LDH eye-specific $C_4$ isozymes in L. macrochirus and M. salmoides were reduced at concentrations greater than 0.2 mM and 0.1 mM of pyruvate, respectively. These concentrations remained at 5.2% and 15.8% as a result of the inhibition by 10 mM of pyruvate, so the degree of inhibition was very high. The LDH activities of eye tissues were reduced at concentrations greater than 22 mM and 24 mM of lactate, respectively, in L. macrochirus and M. salmoides. The ${K_m}^{PYR}$ of eye-specific $C_4$ was 0.088 mM in L. macrochirus and it was 0.033 mM in M. salmoides. The activities of cytosolic and mitochondrial eye-specific $C_4$ isozymes were high in ${\alpha}$-ketobutyric acid. Furthermore, the activities of eye tissue and eye-specific $C_4$ isozyme had to be measured with 0.5 mM of pyruvate and a buffer solution of pH 7.5. As a conclusion, the eye-specific $C_4$ isozyme in M. salmoides has a high affinity for pyruvate and exhibits maximum activity at a lower concentration of pyruvate and at higher concentration of lactate than that in L. macrochirus. Therefore, it seems that the energy produced by the LDH eye-specific $C_4$ isozyme in M. salmoides was used at the first stage of predatory behavior.

• Journal of the Korean earth science society
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• v.32 no.7
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• pp.707-718
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• 2011

We study the natural background and geochemical characteristics on geological groups of stream sediment in the Boseong-Hwasun area. We collected 186ea stream sediment samples along the primary channels and dried them naturally in laboratory. The contents of major, trace and rare earth elements were determined by XRF, ICP-AES and NAA analysis methods. In order to know the natural background and geochemical characteristics of geological groups, we classified the studied area into granitic gneiss (GGn) area and porphyroblastic gneiss (PGn) area. The contents range of major elements for GGn area is $SiO_2$ 45.5-73.09 wt.%, $Al_2O_3$ 12-20.76 wt.%, $Fe_2O_3$(T) 3.72-8.85 wt.%, $K_2O$ 2.38-4.2 wt.%, MgO 0.75-2.77 wt.%, $Na_2O$ 0.78-1.88 wt.%, CaO 0.27-2.1 wt.%, $TiO_2$ 0.56-1.72 wt.%, $P_2O_5$ 0.06-0.73 wt.% and MnO 0.03-0.95 wt.%, and for PGn area it is $SiO_2$ 43.74-70.71 wt.%, $Al_2O_3$ 11.54-25.05 wt.%, $Fe_2O_3$(T) 3.44-13.46 wt.%, $K_2O$ 2.08-3.86 wt.%, MgO 0.65-2.99 wt.%, $Na_2O$ 0.63-1.7 wt.%, CaO 0.35-2.07 wt.%, $TiO_2$ 0.68-4.17 wt.%, $P_2O_5$ 0.1-0.31 wt.% and MnO 0.07-0.33 wt.%. The contents range of hazard elements for GGn area is Cr 41.7-242 ppm, Co 7.6-25.1 ppm, Ni 12-61 ppm, Cu 10-47 ppm, Zn 48.5-412 ppm, Pb 17-215 ppm, and for PGn area, it is Cr 29.6-454 ppm, Co 5.9-53.7 ppm, Ni 8.7-287 ppm, Cu 6.4-134 ppm, Zn 43.6-370 ppm, Pb 15-37 ppm area. There is a good correlation between Cr and MgO and Co among $Al_2O_3$, $Fe_2O_3$(T), MgO and Ni among $Fe_2O_3$(T), CaO, MgO whereas Cu, Zn and Pb have a low correlation for major elements in GGn area. Generally Cr, Co, Ni, and Cu have a good correlation with major elements, but a low correlation with Zn and Pb in PGn area.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.4
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• pp.111-124
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• 2010

To monitor the environment of land surface change is considered as an important research field since those parameters are related with land use, climate change, meteorological study, agriculture modulation, surface energy balance, and surface environment system. For the change detection, many different methods have been presented for distributing more detailed information with various tools from ground based measurement to satellite multi-spectral sensor. Recently, using high resolution satellite data is considered the most efficient way to monitor extensive land environmental system especially for higher spatial and temporal resolution. In this study, we use two different spatial resolution satellites; the one is SPOT/VEGETATION with 1 km spatial resolution to detect coarse resolution of the area change and determine objective threshold. The other is Landsat satellite having high resolution to figure out detailed land environmental change. According to their spatial resolution, they show different observation characteristics such as repeat cycle, and the global coverage. By correlating two kinds of satellites, we can detect land surface change from mid resolution to high resolution. The K-mean clustering algorithm is applied to detect changed area with two different temporal images. When using solar spectral band, there are complicate surface reflectance scattering characteristics which make surface change detection difficult. That effect would be leading serious problems when interpreting surface characteristics. For example, in spite of constant their own surface reflectance value, it could be changed according to solar, and sensor relative observation location. To reduce those affects, in this study, long-term Normalized Difference Vegetation Index (NDVI) with solar spectral channels performed for atmospheric and bi-directional correction from SPOT/VEGETATION data are utilized to offer objective threshold value for detecting land surface change, since that NDVI has less sensitivity for solar geometry than solar channel. The surface change detection based on long-term NDVI shows improved results than when only using Landsat.

• Korean Chemical Engineering Research
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• v.54 no.5
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• pp.671-677
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• 2016

The impregnated alkali metal (Na, K), and the alkali earth metal (Ca, Mg) activated carbons were produced from the bamboo activated carbon by soaking method of alkali metals and alkali earth metals solution. The carbonization and activation of raw material was conducted at $900^{\circ}C$. The specific surface area and the pore size distribution of the prepared activated carbons were measured. Also, NO and activated carbon reaction were conducted in a thermogravimetric analyzer in order to use for de-NOx agents of the used activated carbon. Carbon-NO reactions were carried out in the nonisothermal condition (the reaction temperature $20{\sim}850^{\circ}C$, NO 1 kPa) and the isothermal condition (the reaction temperature 600, 650, 700, 750, 800, $850^{\circ}C$, NO 0.1~1.8 kPa). As results, the specific volume and the surface area of the impregnated alkali bamboo activated carbons were decreased with increasing amounts of the alkali. In the NO reaction, the reaction rate of the impregnated alkali bamboo activated carbons was promoted to compare with that of the bamboo activated carbon [BA] in the order of BA(Ca)> BA(Na)> BA(K)> BA(Mg) > BA. Measured the reaction orders of NO concentration and the activation energy were 0.76[BA], 0.63[BA(Na)], 0.77[BA(K)], 0.42[BA(Ca)], 0.30 [BA(Mg)], and 82.87 kJ/mol[BA], 37.85 kJ/mol[BA(Na)], 69.98 kJ/mol[BA(K)], 33.43 kJ/mol[BA(Ca)], 88.90 kJ/mol [BA(Mg)], respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.1
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• pp.35-45
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• 2020

This study focused on the park as a space to support the behavior of urban citizens in modern society. Modern city parks are not spaces that play a specific role but are used by many people, so their function and meaning may change depending on the user's behavior. In addition, current online data may determine the selection of parks to visit or the usage of parks. Therefore, this study analyzed the change of behavior in Yeouido Park, Yeouido Hangang Park, and Yangjae Citizen's Forest from 2000 to 2018 by utilizing a time series analysis. The analysis method used Big Data techniques such as text mining and social network analysis. The summary of the study is as follows. The usage behavior of Yeouido Park has changed over time to "Ride" (Dynamic Behavior) for the first period (I), "Take" (Information Communication Service Behavior) for the second period (II), "See" (Communicative Behavior) for the third period (III), and "Eat" (Energy Source Behavior) for the fourth period (IV). In the case of Yangjae Citizens' Forest, the usage behavior has changed over time to "Walk" (Dynamic Behavior) for the first, second, and third periods (I), (II), (III) and "Play" (Dynamic Behavior) for the fourth period (IV). Looking at the factors affecting behavior, Yeouido Park was had various factors related to sports, leisure, culture, art, and spare time compared to Yangjae Citizens' Forest. The differences in Yangjae Citizens' Forest that affected its main usage behavior were various elements of natural resources. Second, the behavior of the target areas was found to be focused on certain main behaviors over time and played a role in selecting or limiting future behaviors. These results indicate that the space and facilities of the target areas had not been utilized evenly, as various behaviors have not occurred, however, a certain main behavior has appeared in the target areas. This study has great significance in that it analyzes the usage of urban parks using Big Data techniques, and determined that urban parks are transformed into play spaces where consumption progressed beyond the role of rest and walking. The behavior occurring in modern urban parks is changing in quantity and content. Therefore, through various types of discussions based on the results of the behavior collected through Big Data, we can better understand how citizens are using city parks. This study found that the behavior associated with static behavior in both parks had a great impact on other behaviors.