• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6852-6859
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• 2015

The purpose of this study was to determine the growth characteristics and distribution pattern of a brackish water clam Corbicula japonica in Seomjin River. Field samples were taken from 14 stations with salinity gradients during spring. Salinity at the bottom layer ranged from 1.0 psu to 32.9 psu, with low salinities in the upper area of the river. In particular, salinity at St.11 was decreased drastically to be ca. 15.0 psu, indicating an intermediate salinity zone. The distribution pattern of C. japonica was related to the salinity gradient, with the highest densities of $2,102ind.m^{-2}$ at Station 13, followed by $1,507ind.m^{-2}$ at Station 11. Here, we focused on the growth characteristics of collected C. japonica collected at two stations with different salinity values. The relationship between shell length and total weight was highly correlated ($R^2=0.91$, P<0.001) at Station 13 compared to that at Station 11 ($R^2=0.72$, P<0.001). On the other hands, the degree of correlation between shell length and shell height (SH) or shell width (SW) at Station 11 (SH: $R^2=0.91$, P<0.001; SW: $R^2=0.69$, P<0.001) was higher than that at Station 13 (SH: $R^2=0.64$, P<0.001; SW: $R^2=0.48$, P<0.001). In addition, fatness index of C. japonica at Station 13 was significantly (P < 0.001) higher than that at St. 11 (t-test value=-22.8, p<0.001). This implies that C. japonica at Station 13 might have enhanced their somatic growth, whereas C. japonica at Station 11 might have this kind of defense mechanism their internal organization against the salinity stress. Ecologically, this kind of defense mechanism of C. japonica against salinity flucuation may play an important role in their survival strategy.

• Korean Journal of Psychosomatic Medicine
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• v.11 no.2
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• pp.182-195
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• 2003

Background: Marriage is one of the major life events and the primary source of individual happiness and meaning of life. It is not possible to predict who will marry whom and which marriage will be successful. Marital adjustment has significant influences on an individual and relationship functioning and is associated with mental health. Good marital quality may imply good general relationship. There are several factors that correlate with or predict good marital quality. Especially individual personality factors may be a major factor in achieving and maintaining marital stability, satisfaction and happiness. The aim of the present study was to investigate the possible relationship between dyadic adjustment and personality dimensions in urban married women. Methods: Dyadic Adjustment Scale, Eysenck's Personality Questionnaire, Beck Depression Inventory and State-Trait Anxiety Inventory were administered to 215 married women. Data analysis was based on 170 women who provided reliable informations. The descriptive statistics of demographic data and 4 scales were obtained. Then the possible relationships between each data were tested by calculating Pearson's product moment correlations. To test the effects of depression and anxiety on dyadic adjustment, stepwise multiple regression analysis was done. Results: Age and length of marriage were negatively correlated with affectional expression and dyadic cohesion. Educational level was positively correlated with total dyadic adjustment score and dyadic satisfaction. Family income was positively correlated with total dyadic adjustment score, dyadic consensus, dyadic satisfaction and dyadic cohesion. Different family type showed different total dyadic adjustment score, dyadic satisfaction and dyadic cohesion. Psychoticism was negatively correlated with total dyadic adjustment score, dyadic consensus, dyadic satisfaction, affectional expression and dyadic cohesion. Neuroticism was negatively correlated with total dyadic adjustment score, dyadic consensus, dyadic satisfaction and affectional expression. Extraversion and lie were not correlated with any factors. Beck Depression Inventory and State-Trait Anxiety Inventory scores were negatively correlated with total dyadic adjustment score, dyadic consensus, dyadic satisfaction, affectional expression and dyadic cohesion. The result of multiple regression analysis indicated that psychoticism was correlated with dyadic adjustment. Conclusion: These results showed that the demographic factors such as age, length of marriage, educational level, family income and family type were significantly correlated with dyadic adjustment. Psychoticism and neuroticism measured by Eysenck Personality Inventory were significantly correlated with dyadic adjustment. But the correlations with extraversion and lie were not significant. Especially correlation between neuroticism and dyadic adjustment seemed to be mediated by emotional state such as depression and anxiety. These findings suggest that personality factors may be involved in marital relationship and that clinician must consider personality aspect in dealing with marital problems. Future study about differences between control group and psychiatric patient group will be needed.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.158-175
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• 2005

Statement of problem. Every effort has been continually made to obtain objectivity in measuring the longevity of fixed restorations, such as by establishing unified judgement standard for deciding success and adopting statistical method that analyzes the data of successful and failed cases at the same time. In Korea, however desired level of development has not to be made in this field yet. Purpose. This study, adopting California Dental Association (CDA) quality evaluation system, established objective standard for deciding success, and inferred the longevity of fixed restorations and their failure analysis through adopting Kaplan-Meier survival analysis. Material and method. In order to assess the longevity of flxed restorations serviced in Korea and causes of failure, a total of 1109 individuals (aged 15-74, 716 women and 393 men loaded with 2551 unit fixed restorations, and 1934 abutments) who lived in Kyung-In Province were examined and the findings were as follows : Results. 1. Length of service of fixed restorations serviced in Korea was 6.86$\pm$0.15 yr (mean), 5.5 yr (median), and the rate of success was 65.82% in 5 year survival, and 21.15% in 10 year survival. 2. When there was patient's need for replacing old prosthetics, longevity of fixed restorations was 7.51$\pm$0.27 yr (mean), 7 yr (median), and the rate of success was 61.08% in 5 year survival, and 17.57% in 10 year survival. 3. Longevity of fixed restorations was longest in the over-sixty age group(9.21$\pm$0.66) and that of the teen age group(3.39$\pm$0.28) was shortest (p<0.05). 4. Longevity of fixed restorations of women (7.38$\pm$0.18 years) was longer than that of men (6.00$\pm$0.26) (p<0.05). 5. As for the provider factor (such as unlicensed performers, university hospitals, and private clinic), there was no statistically significant difference in longevity of fixed restorations. 6. Defective margin (34.78%). periodontal disease (12.15%), periapical involvement (11.73%), was the most frequent causes of failure and poor esthetics group showed the longest life above all (p<0.05). Actual frequent causes of failure after removing old prosthetics were defective margin, periapical involvement, periodontal disease and uncemented restoration. In 75.67% of the cases, abutment state after removing old prosthetics was good enough for loading another prosthetics. 7. There was found to have statistically significant influence between longevity of single crown (6.35$\pm$0.20 yr) and that of 3 unit fixed restorations (7.60$\pm$0.30 y) (p<0.05). In each case the most frequent cause of failure was defective margin. 8. The number of cantilever pontic, pontic/abutment ratio, oral hygiene status were found to have no statistically significant influence on longevity of fixed restorations in all groups (p>0.05). 9. Longevity of fixed restorations made of non precious metal was longest (9.60$\pm$0.40 yr) semi precious and precious trailing behind(p<0.05). 10. Group function group (37.04%) and partial group function group (44.62%) were predominant in frequency but showed no correlation between them and among different types of occlusal plane and different types of occlusal surface (p>0.05). 11. Longevity of fixed restorations was longest in the centric interference group(9.35$\pm$0.62) (p<0.05) among different types of occlusal interference. Conclusion. We found that longevity of fixed restorations serviced in Korea is affected by age, gender and type of material, and that most frequent cause of failure is defective margin. In order to assess the accurate longevity of axed restorations, unified research design. overcoming inter-observer difference and establishing the objective research items are needed. Furthermore, it is thought that prospective approach through thorough study and regular follow-ups is needed just from the start of research. Nationwide detailed studies on length of service of fixed restorations manufactured in Korea are hoped to be conducted hereafter.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.207-220
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• 2006

The newly developed equipments for the early detection of carious lesion are LFD (laser fluorescence device), Ultrasonic diagnostic system, CLSM(confocal laser scanning microscopy), QLF(quantitative light-induced fluorescence) and DIFOTI (digital imaging fiber-optic trans-illumination) system. In this study, DIFOTI system and LFD were used for the detection of early enamel caries. Twenty five primary teeth extracted from twenty one children at around the dentitional exchanging period were selected as samples. The results obtained from DIFOTI imaging and LFD measurement were compared with those of CLSM and comprehensive evaluations were made for the diagnostic capacity of each device. In vitro test, 40 sample teeth with their buccal & lingual surface formed by a window of $2{\times}3mm$ in diameter were immersed in artificial demineralizing solution for the period of 4, 8, 12 and 16 days. The results obtained from the experimental groups (DIFOTI, LFD) were compared to control group (CLSM) and we have reached to the following conclusions. 1. The sensitivity and specificity of DIFOTI system operated in oral environment was 88.2% and 76.9% respectively. 2. The sensitivity and specificity of LFD measured in oral environment was 76.5% and 69.2% respectively. 3, Regression analysis on the light transparent rate of DIFOTI showed its decrease according to the length of primary enamel decalcification performed in vitro(r=-0.96, p<0.05). 4. No statistically significant difference between LFT measurement and the length of in vitro decalcification was found in regression analysis (p>0.05). 5. The correlation coefficient of DIFOTI image transparent rate and the lesion depth of CLMS was -0.6988 (p<0.05), whereas no statistically significant difference was found for LFD measurement.

• Sleep Medicine and Psychophysiology
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• v.8 no.1
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• pp.22-29
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• 2001

Objectives: Obstructive sleep apnea syndrome (OSA) is a moderately prevalent disorder. Even though much progress has been made in the diagnosis of this disorder, the cost-effectiveness of nocturnal polysomnography is undertermined and physicians and patients are still hesitant to undergo this procedure. The authors wanted to see the validity of chin press/tongue curl maneuver in estimating the severity of OSA which is easy to measure and was originally proposed by Simmons etc. by looking at the correlations between this score and the conventional respiratory disturbance indices. Methods: Forty-three sleep-related breathing disorder patients (28 OSA patients and 15 upper airway resistance syndrome (UARS) patients) who underwent investigation for posssible OSA were studied. Two conventional indices of OSA (apnea/hypopnea index (AHI) and oxygen saturation dip rate (SaO2 dips)), four other sleep variables (lowest SaO2, % of time with SaO2<90% (%SaO2 <90), % of sleep stage 1, mean length of SaO2 dips) and the score of Epworth sleepiness scale (ESS) were compared with the chin press score (CPS) which was newly revised by the author and ranges from 0 to 6. Results: The age of subjects was $45.95{\pm}12.47$ (range 14-76) and their average BMI was $25.98{\pm}3.61$ (range 19.65-37.64). There were no significant differences in age, sex and BMI except repiratory disturbance indices and ESS (p<0.05) between OSA and UARS group. Grouped median CPS of the all subjects was 4.14 (range 1-6). There was a remarkable relationship between CPS and diagnosis category (Likelihood Ratio $X^2$ test; $X^2$=17.41, df=5, p=0.004) and measures of association (Somers' $d=0.65{\pm}0.12$, t=4.83, p=0.000) indicated that CPS increased when the diagnosis changed from UARS to OSA. Spearman's rank correlations between CPS and SaO2 dips (R=0.83), between CPS and AHI (R=0.77) were good (p<0.001). Other variables except mean length of SaO2 dips showed good correlations with CPS as well (p<0.05). Regression analysis indicated that when CPS is 3 there is a provability of 0.35 to have AHI of less than 5. Conclusion: Chin press scores that can be measured easily is well correlation with the conventional sleep apnea indices. They may therefore provide a useful guide in diagnosing obstructive sleep apnea synrome.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.28-40
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• 2010

Purpose: The aim of this retrospective study was to provide long-term data about the correlation between multifactorial local factors and the survival of implants. Material and methods: During 19 years (1991 to 2009), 2796 implants were placed in 879 patients. From dental charts and radiographs, the following data were collected: patient's age at implant placement, gender, implant system, surface, length, diameter, location of implant placement, bone quality, primary stability, type of prosthesis. The correlations between these data and implant survival were analyzed. Statistical analysis was performed using Kaplan-Meier survival analysis, Chi-square test, odds ratio. Results: 1. Among the 2796 implants, 150 implants failed that resulted in a cumulative survival rate of 94.64%. The cumulative survival rate of smooth surface implants (91.76%) was lower than rough surface implants (96.02%). 2. Anatomic location, implant surface, diameter of smooth surface implant, primary stability, type of prosthesis, patient's age and gender were significantly associated with implant survival (P < .05). 3. No significant difference in implant survival was found in relation to the following factors: implant length, bone quality, diameter of rough surface implants and type of rough surface according to implant manufacturer (P < .05). Conclusions: Local factors such as anatomic location, implant surface, diameter of smooth surface implant, primary stability and type of prosthesis have a significant effect on implant survival.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.4
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• pp.87-97
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• 2015

There's a trend towards vitalization of nightscape planning businesses nationally and locally as well for city image making and activation of regional economy, but there is still no systematic nightscape planning going on for lack of relevant researches and objective evaluations. This study aims to suggest the guideline for nightscape planning by conducting an eye tracking experiment and survey for recognizing the characteristics of a nightscape. Furthermore, the authors intended to verify the eye-tracking method as a tool for landscape evaluation. The research site was restricted in the campus of Virginia Tech, VA, and those were selected by experts' survey among various types of nightscape images. The variables for analyzing the characteristics of nightscape images selected were 'preference', 'safety(fear)' and 'clearness'. 'Fixation duration', 'saccade duration', 'scan path length', and 'pupil size' were selected as the eye movement measurements. The results of this study are as follows: The first outcome found was that there were significant differences among the characteristics(preference, safety and clearness) of a nightscape by MANOVA, and these variables were correlated positively by Pearson's correlation. Secondly, there were differences on fixation duration, saccade duration and scan path depending on the nightscape setting statistically. Also, the eye tracking measurement in an open setting was recorded lower than enclosed settings. In the result of a heat map, we found the meaning of the fixated areas on both viewing without intention and viewing intentionally. It turned out that the fixated areas were consistent with the areas the subjects felt preferred and clarity in all of the nightscape images, which means people usually focus on what they prefer and see clearly in a certain nightscape. Based on this result and previous studies, the authors could make a conclusion that eye tracking method can apply to evaluate nightscape settings in terms of analyzing the whole characteristics and finding specific points for the detailed analysis as well. Therefore, these results can contribute by suggesting nightscape planning, implication of the landscape evaluation, and implication of the eye tracking study.

• Korean Journal of Ecology and Environment
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• v.37 no.3 s.108
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• pp.332-343
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• 2004

This study was conducted to test a possibility of water quality improvement using a filter-feeding bivalve (Corbicula leana). In mesocosm scale (width ${\times}$ length ${\times}$ depth: 3 m ${\times}$ 3 m ${\times}$ 0.5 m), we investigated the changes of dissolved nutrient and particulate matter including both abiotic and biotic seston. Short term (16 days) mesocosm experiment was conducted in two stages: the first stage for 8 days and consecutive 8 days of the second stage. Both treatment and control mesocosm were switched over by translocating mussels from the treatment mesocosm to the control, at 8th days since the start of the experiment. This design made it possible to compare mussel effect on the water quality change more clearly. The high mortality of mussel was observed in the treatment of the first stage, but it decreased rapidly and stabilized on the 8th day to less than< 4 ind $day^{-1}$. Chl. a concentration in the treatment mesocosm of the first and second stage decreased to 71 and 88% of initial concentration, respectively, and suspended solids decreased to 70 and 77%. At those times, average filtering rate were 0.46 and 0.61 mL AFDW $mg^{-1}$ $hr^{-1}$, respectively. Both $NH_3-N$ and dissolved total phosphorus (DTP) concentrations increased with the mussel mortality. $NH_3-N$ concentration was positively correlated with the mussel mortality, while DTP concentration showed negative correlation with it. After translocating mussel from the treatment to the control, $NH_3-N$ concentration significantly increased compared with that of initial control. Although DTP concentration also increased, there was no significant difference relative to that of initial control. These results suggest that application of this filter-feeding bivalve in a eutrophic reservoir could be a potential tool to improve water quality if mussels could acclimatize successfully in early stage of the introduction.

• Journal of Korean Society of Forest Science
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• v.79 no.4
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• pp.359-366
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• 1990

This study was carried out to investigate rooting rate, plagiotrophic growth and root-promoting effect of IBA in Taxus cuspidata S, et Z. cuttings. The results obtained were summarized as follows ; 1. As the ortet ages of cuttings were increased in 5, 10, to 20 years, the rooting rates were decreased in order of 85.7%, 81.7% and 62.4%, and the number of primary roots were also decreased in 5.3, 3.7 and 2.9, respectively. 2. Rooting rate by cutting types of lateral shoot were higher than those of main shoot type, significant at the 1% level. 3. IBA(l00ppm) treatment promoted the rooting rates and the number of primary roots. 4. As the ortet ages were increased in 5, 10 to 20 years, angles of central shoot of rooted cuttings which mesured cyclophysis were decreased in order of $75.9^{\circ}$, $68.5^{\circ}$ and $59.6^{\circ}$, respectively, significant at the 1% level. 5. Average angles showed $77.0^{\circ}$ for main shoot cutting, $65.9^{\circ}$ for upper lateral shoot and $61.7^{\circ}$ for lower lateral, which was significant at 1% level, and lateral shoot cutting showed more topophysis than main shoot cutting. 6. Shoot length of rooted cuttings from main shoot cutting was longer than that from lateral shoot significant at the 1% level. 7. Relationship between some characteristics showed highly positive correlation.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.420-428
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• 2009

In this study, the variation of 20 Pinus thunbergii isolates of F. circinatum from 2 damaged sites in Jeju-Island were compared with a known Fusarium circinatum using molecular biological techniques. Two- and four-year-old seedlings of Pinus rigida${\times}$Pinus x rigitaeda and two-, three- and six-year-old seedlings of P. thunbergii were inoculated with one of the most virulent isolates, FT-7, to determine differences in susceptibility. In site 1 (FT), 13 isolates of F. circinatum were isolated from 14 individuals and in site 2 (FS), 7 isolates of F. circinatum were isolated from 9 individuals. No difference was found in the sequences of the internal transcribed spacer (ITS) region of the ribosomal RNA genes in the FS and FT isolates, and also even in the known isolate of F. circinatum, FE 1-1. However, the ITS sequences of the FS and FT isolates differed from those of a fungus, Botrytis cinerea. Two-year-old seedlings of P. rigida${\times}$P. x rigitaeda showed higher susceptibility (93.3% of mortality) than four-year-old ones. Three-year-old seedlings of P. thunbergii showed the highest susceptibility (66.7% of mortality) compared to those at other ages in the same species. We found a positive correlation between basal diameter and lesion length in the seedlings of P. rigida${\times}$P. x rigitaeda ($R^2=0.66$) and P. thunbergii (p < 0.0001), respectively. There were significant differences in susceptibility by the age of seedlings in each of P. rigida${\times}$P. x rigitaeda (p < 0.0001) and P. thunbergii (p < 0.0001) based on lesion length.