• Korean Journal of Materials Research
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• v.4 no.7
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• pp.759-766
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• 1994

Our investigation aimed to reduce the leakage current of $Ta_2O_5$ thin film capacitor by layering SnOz thin film layer under Ta thin film, thereby supplying extra oxygen ions from the $SnO_{2}$ underlayer to enhance the stoichiometry of $Ta_2O_5$ during the oxidation of Ta thin film. Tantalum was evaporated by e-beam or sputtered on p-Si wafers with various deposition temperatures and was oxidized by dry--oxygen at the temperatures between $500^{\circ}C$ and $900^{\circ}C$. Aluminum top and bottom electrodes were formed to make Al/$Ta_2O_5$/p-Si/Al or $Al/Ta_2O_5/SnO_2$p-Si/AI MIS type capacitors. LCR meter and pico-ammeter were used to measure the dielectric constants and leakage currents of the prepared thm film capacitors. XRD, AES and ESCA were employed to confirm the crystallization of the thin f~lm and the compositions of the films. Dielectric constant of $Ta_2O_5$ thin film capacitor with $SnO_{2}$ underlayer was found to be about 200, which is about 10 times higher than that of $Ta_2O_5$ thin film capacitor without $SnO_{2}$ underlayer. In addition, higher oxidation temperatures increased the dielectric constants and reduced the leakage current. Higher deposition temperature generally gave lower leakage current. $Ta_2O_5/SnO_2$ capacitor deposited at $200^{\circ}C$ and oxidized at $800^{\circ}C$ showed significantly lower leakage current, $10^{-7}A/\textrm{cm}^2$ at $4 \times 10^{5}$V/cm, compared to the one without $SnO_{2}$ underlayer. XRD showed that $Ta_2O_5$ thin film was crystallized above $700^{\circ}C$. AES and ESCA showed that initially the $SnO_{2}$, underlayer supplied oxygen ions to oxidize the Ta layer, however, Sn also diffused into the Ta thin film layer to form a new $Ta_xSn_YO_Z$ , ternary oxide layer after all.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.7
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• pp.935-945
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• 2009

This study was performed to find the optimum ratio of ingredients in the Chinese quince jam. The experiment was designed according to the D-optimal design of mixture design, which included 14 experimental points with 4 replicates for three independent variables (Chinese quince paste $45{\sim}60%$, pectin $1.5{\sim}4.5%$, sugar $45.5{\sim}63.5%$). A mathematical analytical tool was employed for the optimization of typical ingredients. The canonical form and trace plot showed the influence of each ingredient in the mixture against final product. By use of F-test, sweetness, pH, L, b, ${\Delta}E$, and firmness were expressed by a linear model, while the spreadmeter value, a, and sensory characteristics (appearance, color, smell, taste, and overall acceptability) were by a quadratic model. The optimum formulations by numerical and graphical method were similar: Chinese quince paste 54.48%, pectin 2.45%, and sugar 53.07%. Optimum ingredient formulation is expected to improve use of Chinese quince and contribute to commercialization of high quality Chinese quince jam.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.2
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• pp.21-26
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• 2016

Purpose Because of many advantages, PET-CT Scanners generally use CT Data for attenuation correction. By using CT based attenuation correction, we can get anatomical information, reduce scan time and make more accurate correction of attenuation. However in case metal artifact occurred during CT scan, CT-based attenuation correction can induce artifacts and quantitative errors that can affect the PET images. Therefore this study infers true SUV of metal artifact region from attenuation corrected image count -to- non attenuation corrected image count ratio. Materials and Methods Micro phantom inserted $^{18}F-FDG$ 4mCi was used for phantom test and Biograph mCT S(40) is used for medical test equipment. We generated metal artifact in micro phantom by using metal. Then we acquired both metal artifact region of correction factor and non metal artifact region of correction factor by using attenuation correction image count -to- non attenuation correction image count ratio. In case of clinical image, we reconstructed both attenuation corrected images and non attenuation corrected images of 10 normal patient($66{\pm}15age$) who examined PET-CT scan in SNUH. After that, we standardize several organs of correction factor by using attenuation corrected image count -to- non attenuation corrected count ratio. Then we figured out metal artifact region of correction factor by using metal artifact region of attenuation corrected image count -to- non attenuation corrected count ratio And we compared standard organs correction factor with metal artifact region correction factor. Results according to phantom test results, metal artifact induce overestimation of correction factor so metal artifact region of correction factors are 12% bigger than the non metal artifact region of correction factors. in case of clinical test, correction factor of organs with high CT number(>1000) is $8{\pm}0.5%$, correction factor of organs with CT number similar to soft tissue is $6{\pm}2%$ and correction factor of organs with low CT number(-100>) is $3{\pm}1%$. Also metal artifact correction factors are 20% bigger than soft tissue correction factors which didn't happened metal artifact. Conclusion metal artifact lead to overestimation of attenuation coefficient. because of that, SUV of metal artifact region is overestimated. Thus for more accurate quantitative evaluation, using attenuation correction image count -to-non attenuation correction image count ratio is one of the methods to reduce metal artifact affect.

• Journal of Oriental Neuropsychiatry
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• v.19 no.3
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• pp.143-169
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• 2008

Objective: This study was to investigate the relation of what insomnia patients' symptoms with Heart Rate Variability(HRV), Pittsburgh Sleep Quality Index (PSQI) and Insomnia Questionaire(IQ). Methods: For this study, we carried out HRV, PSQI and IQ of 43 patients with insomnia who have come to Donguei oriental hospital of Donguei university from September 2007 to May 2008. We studied the relationship HRV with PSQI and IQ. For every symptom, this study classified the patients as none-symptom, symptom groups and analyzed each group's HRV, PSQI and IQ. Result : 1. The rate of xerostomia in female group is significantly higher than male group. 2. P1 (hypnagogic time), P3(awakening time), LF has negative correlation with age. The score of PI (hypnagogic time), P3(awakening time), P4(time of recoverable sleep) in the group whose age is more than 50 are higher than the group whose age is lesser than 50. 3. The frequency of using hypnotics(P6) in the group whose duration of onset are over 1 year was significantly higher than the score in the group whose duration of onset were below 1 year. 4. The accompanied symptoms in the group who started sleep disorder after stressor are higher than the number in the group whose duration of onset were poor-defined. 5. The drinking group have lower rate of anorexia, higher score of P1 (hypnagogic time) and TP than non-drinking group. 6. The score of P-total(general quality of sleep) have negative correlation with NNSO, HF, TP and positive correlation with LF/HF. 7. The score of P1(hypnagogic time) have negative correlation with LF. 8. The score of P5a(frequency of delayed hypnagogue) have positive correlation with LF/HF. 9. The score of P5e(frequency of cough or snoring) have negative correlation with RMSSD. 10. The score of I1a(degree of onset insomnia), I1b(degree of maintenance insomnia) have negative correlation with NN50, pNN50, HF. 11. The score of I1c(degree of termination insomnia) have negative correlation with RMSSD, NN50, pNN50, HF, TP and positive correlation with MHR, LF/HF. 12.. The score of P5i(frequency of night pain), LF/HF in the group with headache are higher than the group without headache. 13. The score of P5a(frequency of delayed hypnagogue), P5c(frequency of awakening for urine of stool) in the group with xerostomia are higher than the group without xerostomia. 14. The score of P9(degree of unrecoverable sleep) and I5a(degree of onset insomnia) in the group with chest discomfort are lower than the group without chest discomfort. 15. The score of P7(frequency of drowsiness for daytime) in the group with palpitation are lower than the group without palpitation. 16. The score of P5c(frequency of awakening for urine of stool), P5f(frequency of burning sensation), P5h(frequency of nightmare), I1c(degree of termination insomnia) in the group with burning sensation of upper trunk are higher than the group without burning sensation. 17. The score of NN50, pNN50, LF, TP in the group with anorexia are lower than the group without anorexia. 18. The score of P-total(general quality of sleep), P2(duration for sleep start) in the group with constipation are higher than the group without constipation. 19. The score of P4(recoverable sleep time) in the group with depression are higher than the group without depression. 20. In the group with anxiety, the score of P1(time of hypnagogue), P5a(frequency of onset insomnia) are lower and the score of I1b(degree of maintenance insomnia), I4(objective degree of impairment by insomnia) are higher than the group without anxiety. 21. The score of NN50, pNN50, HF, TP in the group with inertia are lower than the group without inertia. 22. The accompanied symptoms haver posirive correlation with P5f(frequency of burning sensation), P5h(frequency of nightmare), P5i(frequency of night pain) and LF/HF. Conclusion: This study provides insights into the complicated relations of the pattern of sleep disorder with many symptoms such as headache, chest discomfort, depression and any others. And this study showed that autonomic nervous system have important function in the regulation of sleep.

• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.1101-1106
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• 2006

Many BNR (Biological Nutrient Removal) plants have experienced a bulking problem, mainly due to the growth of filamentous organisms, particularly during the winter months. This study investigated the problem of bulking due to the growth of M. parvicella both at a full-scale municipal wastewater treatment plant and a pilot scale plant located in the C city. The full-scale facility was operated at a flow rate of $51,000m^3/d$, an F/M (Food-to-Microorganism) ratio of 0.12 kgBOD/kgMLVSS/d and an SRT (Solids Retention Time) higher than 25 days, respectively. This plant experienced bulking and foaming problems at low temperatures below $15^{\circ}C$ since it was retrofitted with the BNR system in 2003. The pilot plant employed had an identical process configuration as the full scale one and used the same wastewater source. It was operated at a flow rate of $3.8m^3/d$, temperatures between 10 to $25^{\circ}C$ and SRTs between 10 and 25 days. At full scale, the M. parvicella growth and SVI (Sludge Volume Index) patterns were studied in conjunction with temperature variations. At pilot scale, DO and SRT variations were also explored, in addition to the filamentous bacteria growth and SVI patterns. During the full-scale investigation, over a 3 year period, it was noted that the SVI was maintained within acceptable operational values (i.e. under 160) during the summer months. Moreover settling in the secondary clarifiers was good and was not affected by the presence of M. parvicella. In contrast, at low mean temperatures during winter, the SVI increased to over 300. Overall, as the temperature decreased, the predominance of M. parvicella became apparent. According to this study, M. parvicella growth could be controlled and SVI could drop under 160 by a change in operational conditions which involved an increase in DO concentration between 2 and 4 mg/L and a decrease in SRT to less than 20 days.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.409-419
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• 2001

This study was to examine whether the in vitro friability, motility and intact acrosome of frozen-thawed bovine and human sperm can be improved by adding Pentoxifylline (PF) or Fertilization Promoting Peptide (FPP). Human semen was frozen ultra-rapidly using Test yolk-buffer (TYB) freezing medium. Additive (PF, FPP) effects in frozen-thawed bovine and human sperm were analyzed by microscopic count for sperm motility and coomassie brilliant blue staining method f3r sperm acrosome intact. The in vitro motility of frozen-thawed bovine sperm with 5 mM PF treatment group (50.0%) was significantly higher than that of control (34.0%) (P＜0.05). In the frozen-thawed bovine sperm was examined, the intact acrosome rate of 50 nM FPP treatment (49.0%) was significantly higher than those of control (30.0%) and 25 nM FPP (38.0%) treatment groups (P＜0.01). In human semen, when in vitro motility of sperm with PF addition prior to freezing was examined, the result of 5 mM treatment group (51.0%) was significantly higher than those of control and 2.5 mM treatment group (39.0, 40.0%) (P＜0.01). In addition, 50 nM (75.5%) FPP adding in all treatment procedures for human semen freezing (before freezing, freezing and after thawing) was significant effect on maintenance of the sperm intact acrosome percentage (control: 45.0; 25 nM: 53.0; 100 nM: 68.0%) (P＜0.01). Also, the intact acrosome rate of human sperm with FPP (65.0%) was significantly higher than that with PF (43.0%) (P＜0.05), although sperm motility was slightly higher in PF treatment group. These results suggest that improved sperm motility and intact acrosome of frozen thawed bovine and human sperm can be obtained by addition of PF or FPP, and that the enhanced in vitro viability, motility and intact acrosome can be obtained by addition of FPP in all semen freezing procedures.

• Korean Journal of Environment and Ecology
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• v.23 no.5
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• pp.447-459
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• 2009

This study is intended to provide basic date for the efficient management of Pinus densiflora community by analyzing ecological characteristics of Pinus densiflora inhabiting Byeonsanbando National Park. According to investigations, P. densiflora community and P. densiflora-Quercus community are widely distributed, occupying 40.3% of the total area. 21 sites ($400m^2$per site) are selected for TWINSPAN analysis, and the result indicates that the whole community of P. densiflora and P. densiflora-Quercus can be classified into 8 types, and the age of P. densiflora is 40-50 years, which is similar to that of deciduous broad-leaved trees. The 8 community types are: P. densiflora community which competes with Quercus variabilis; P. densiflora community in which Fraxinus sieboldiana and Quercus serrata grow in the understory layer; P. densifloa community in which Q. serrata grow in the understory layer and Smilax china var. microphylla in the shrub layer respectively; P. densifloa community in which P. densiflora and F. sieboldiana grow in the understory layer; P. densiflora community which competes with Q. serrata and Carpinus tschonoskii; P. densiflora community which competes with Q. variabilis and Q. serrata; P. densiflora community in which Prunus sargentii grow; P. densiflora community in which Abies holophylla grow. P. densiflora community which competes with Q. variablis and C. tschonoskii seems to be in a stage of succession to deciduous broad-leaved community. The analysis indicates that Shannon diversity index is 0.2756-1.3879. It also indicates that there is a negative correlation between P. densiflora and Q. variabilis and C. tschonoskii; there is a positive correlation between P. densiflora and F. sieboldiana and Rhododendron schlippenbachii. These investigations show that the transformation of vegetation is already under way. There is a possibility that ecological succession can take place in 30.4% of the total area from P. densiflora to Quercus and deciduous broad - leaved trees. Therefore, it is recommended that the preservation and maintenance of P. densiflora be implemented by taking control of competing species which undermine the stability of P. densiflora forest community.

• Journal of Korean Society of Forest Science
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• v.38 no.1
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• pp.19-26
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• 1978

In order to investigate the difference of rootability between 15 clones of Populus alba${\times}$glandulosa selected based on the growth performance, rooting of cutting experiments with these 15 clones were conducted at the nursery for six years from 1970 to 1975. Cutting experiments in a temperature controlled incubator in which the temperature of the cutting bed were set to $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$ were also performed. Along with these experiments air layering experiments were performed to compare with the rootabilities obtained from nursery trial. The results obtained so far could be summarized as follows. 1. The best rooting clones were 65-22-4 and 65-22-11, and the average rooting percentages of these two clones for six years were 76.7%, and 72.9% respectively. The poorest rooting clone was 66-6-8 showing average rooting percentage of 45.8%. 2. The middle class of rooting percentage was ocuppied by the clones; 66-14-29, 66-14-93, 66-25-5 and 67-6-3, and the range of their rooting percentage was 60~69% on average. 3. The rooting performances observed through the nursery, the incubator and the air layering experiments were almost the same with exception of few clones. 4. P. alba${\times}$glandulosa showed the best rooting percentage at the cutting bed of $20^{\circ}C$ 5. The most roots, i.e. 78.5% of root per cutting were developed from the bottom part of the cutting shoot. 6. Adventitious and call use roots could observe in the cuttings.

• Journal of dental hygiene science
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• v.9 no.2
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• pp.169-179
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• 2009

This study aims to present a fundamental data base to figure out the mental and the physical conditions that the dental technicians are facing and ultimately to develop a health care program to deal with their health related problems. To this end, we took an analysis on the health status among the subjects of 895 dental technicians currently working at the dental lab around the nation from January 15 to March 31, 2009 by way or Todai Health Index(THI). Of the average scale point in accordance with 12 scale scores of the physical and the mental subjective symptom, the results revealed that the physical appeals (21.10) were higher than the mental appeals (18.49) and the multiple subjective symptom was marked as 38.44 followed by the mental irritability (25.92). In gender differences, the females proved to be higher than the males in both physical appeals and mental appeals while the physical appeals were dominant in both genders. The physical appeals were higher than the mental appeals with regard to the general characteristics. In the case or the group or age twenties as shown in the physical and mental average scale point, the other groups showed 21.55% of the physical appeals among the married whereas the mental appeals showed the highest point as 18.70 in the unmarried group. In job position, the other groups marked the highest, in working condition, below average group marked the highest, in frequency of break time, none group marked the highest. We drew a conclusion form this study that the dental technicians gained the higher points in the item or the multiple subjective symptom, the menial irritability, and the irregular life. More research on th is phenomena should be followed along with the development of various and practical health care programs to promote the health or dental technicians.

• Korean Journal of Cognitive Science
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• v.33 no.2
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• pp.109-133
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• 2022

Episodic memory consists of a core event and the associated contexts. Although the role of the hippocampus and its neighboring regions in contextual representations during encoding has become increasingly evident, it remains unclear how these regions handle various context-specific information other than spatio-temporal contexts. Using high-resolution functional MRI, we explored the patterns of the medial temporal lobe (MTL) and cortical regions' involvement during the encoding of various types of contextual information (i.e., journalism principle 5W1H): "Who did it?," "Why did it happen?," "What happened?," "When did it happen?," "Where did it happen?," and "How did it happen?" Participants answered six different contextual questions while looking at simple experimental events consisting of two faces with one object on the screen. The MTL was divided to sub-regions by hierarchical clustering from resting-state data. General linear model analyses revealed a stronger activation of MTL sub-regions, the prefrontal lobe (PFC), and the inferior parietal lobule (IPL) during social (Who), behavioral (How), and intentional (Why) contextual processing when compared with spatio-temporal (Where/When) contextual processing. To further investigate the functional networks involved in contextual encoding dissociation, a multivariate pattern analysis was conducted with features selected as the task-based connectivity links between the hippocampal subfields and PFC/IPL. Each social, behavioral, and intentional contextual processing was individually and successfully classified from spatio-temporal contextual processing, respectively. Thus, specific contexts in episodic memory, namely social, behavior, and intention, involve distinct functional connectivity patterns that are distinct from those for spatio-temporal contextual memory.