• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.26 no.2
• /
• pp.133-145
• /
• 1996

Aspirating or swallowing foreign bodies is a common occurrence. If they are wholly or partly radiopaque, their localization in and progress through the gastrointestinal tract can be more effective. Of the dental origin foreign materials swallowed, the most common things are fragments of anterior maxillary partial denture. But the radiopacity of denture base resins is not sufficient to determine the location of the objects. The purpose of this study was to develop a radiopaque dental acrylic resin, which has clinically detectible radiopacity with minimal change of mechanical properties and color. The radiopacity, color change(CIE 6..E) and microhardness of acrylic resins were determined after mixing barium sulfate or iodide compound. Thermocycling course was conducted to determine the change of characteristic of resins after using for a long time in the mouth. Five or ten percent of barium sulfate to total weight of cured material was mixed with heat curing dental acrylic resin or chemically curing orthodontic resin. In the case of iodide compound, the mixing ratio was two or three percent. After mixing the high radiopaque materials, resin was cured to 20×20×2 mm plate, polished with #600 sand paper and finally polished with Microcloth(Buehler). The specimens were thermocycled in 5 and 55 t distilled water for 2,000 times, and the measurement of radiopacity, color and Vickers hardness was repeated every 500 times thcrmocycling. The radiopacity of specimens on the X -ray films was measured with densitometer(X-rite). The color change was detennined with differential colorimeter(Model TC-6FX, Tokyo Denshoku), and the Vickers hardness number was measured with microhardness tester(Mitsuzawa). The following results were obtained : 1. All the three variables, the kinds of acrylic resins, the mixing or the kinds of high radiopaque materials and thermocycling, had combined effect on the radiopacity of the dental acrylic resins(p<0.0l). 2. The two variables, the mixing or the kinds of high radiopaque materials and thermocycling, influenced on the radiopacity of the dental acrylic resins(p<0.01). But the kinds of acrylic resins did not influence on the color change of mixed dental acrylic resins(p>0.05). 3. Each of the three variables, the kinds of acrylic resins, the mixing or the kinds of high radiopaque materials and thermocycling, influenced on the radiopacity of dental acrylic resins(p<0.0l). 4. The high radiopaque materials used in this study did not yield clinically usable radiopacity, and the color change was great after mixing those materials.

• Korean Journal of Ichthyology
• /
• v.28 no.4
• /
• pp.239-248
• /
• 2016

The habitat, age and spawning characteristics of the Korean eastern spined loach, Iksookimia yongdokensis, were investigated to obtain baseline data for its ecological characteristics in the Chuksancheon (stream), Yeongdeok-gun, Gyeongsangbuk-do, Korea. The difference between the habitats of juveniles (0+) and 1~4 year old loaches was that juveniles mainly inhabited sandy bottoms (substratum particle size $0.6{\pm}1.44\;cm$) with very slow velocities of water current ($2.4{\pm}2.09\;cm/sec$) and low depths ($29.2{\pm}7.57\;cm$), whereas 1~4 year old loaches inhabited pebble and cobble bottoms (substratum particle size 5.5~6.1 cm) with relatively fast velocities of water current (3.8~4.6 cm/sec) and deep depths (50~70 cm). The age groups for I. yongdokensis (female) estimated by the frequency distribution of total length in the spawning season (July) indicated that the 35~64 mm is 1-year old, the 65~94 mm group is 2-year old, the 95~119 mm is 3-year old, and the 120~145 mm is more than 4-year old. The sex ratio (♂/♀) was 0.69, and females were 10~30 mm larger than males. The lamina circularis at the base of the pectoral fins in males, a secondary sexual characteristic, formed at the 13th month after hatching. The spawning season according to the gonadosomatic index (GSI) was June to July with water temperatures of $20{\sim}25^{\circ}C$. The average number of eggs was $2,292{\pm}618$, with a diameter of $1.46{\pm}0.02\;mm$ for mature eggs.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.24 no.2
• /
• pp.339-351
• /
• 1997

The purpose of this study was to investigate the distribution of nerves in the rat circumvallate papilla by each developing stage. The distribution of nerves in the rat circumvallate papilla were investigated by means of immunohistochemistry for detection of calcitonin gene-related peptide(CGRP). The results were as follows : CGRP-immunoreactive(IR) nerve fibers entered the base of the papilla laterally to form a subepithelial plexus. On the 1st postnatal day, the bead-like appearance, typical appearance of CGRP-IR nerve fiber, was seen, but from the 5th postnatal day the bead-like appearance was seen less clearly and nerve fibers looking like a line were often observed. Mature taste buds having taste pores were first seen at the 10th postnatal day and then, increased markedly after this stage. CGRP-IR nerve fibers entering the epithelium were rarely seen on the 5th postnatal day but they increased in number on the 10th postnatal day when mature taste buds having taste pores were firstly observed and then on the 15th postnatal day, they were observed abundantly throughout entire epithelium. But from the 20th postnatal day, the nerve fibers in the lower two-third of the trench wall in which taste buds exist decreased but on the top surface and upper one-third of the trench wall the nerve fibers were observed limitedly.

• The Journal of the Acoustical Society of Korea
• /
• v.32 no.3
• /
• pp.262-268
• /
• 2013

The performances of speech compression schemes appeared to be dependent on the response profiles to compressed stimuli and the features of individual languages to some extent. Although these response profiles were critical in comparing various compression outcomes, the related data were limited in number for Korean monosyllabic words. From the previous study, data from PNT (Preserving No Trait) compression was selected as a base set for comparison. In this study, the outcomes from PPT (Preserving Pitch Trait) and PTT (Preserving Time Trait) were analyzed under the same condition. Then, the properties of these three widely used representative compression schemes were quantitatively compared in normal hearing adults (N=20) for controlled Korean quintet digit sets (0 through 9). Results showed that PPT compression scheme exhibited the best perceptual performances for the Korean quintet digit sets in the final outcomes (PPT>PTT>PNT). The compression ratios of 50% performances were estimated as about 20%, 42%, and 44% for PPT, PTT, and PNT, respectively. The data indicated the influences of the salient psychoacoustic features of the three representative compressions on perceiving Korean monosyllabic digit words. This controlled procedure with monosyllabic quintet sets can evaluate efficiency and effectiveness of other compression schemes and may also contribute to diagnosing auditory processing disorders and fitting special hearing aids with compression issues.

• Journal of Cadastre & Land InformatiX
• /
• v.50 no.1
• /
• pp.181-200
• /
• 2020

This study used the OLS model to estimate the determinants affecting the tenure of a home and then compared the predictive power of each model with SVM, Decision Tree, Random Forest, Gradient Boosting, XGBooest and LightGBM. There is a difference from the preceding study in that the Stacking model, one of the ensemble models, can be used as a base model to establish a more predictable model to identify the volume of housing transactions in the housing market. OLS analysis showed that sales profits, housing prices, the number of household members, and the type of residential housing (detached housing, apartments) affected the period of housing ownership, and compared the predictability of the machine learning model with RMSE, the results showed that the machine learning model had higher predictability. Afterwards, the predictive power was compared by applying each machine learning after rebuilding the data with the influencing variables, and the analysis showed the best predictive power of Random Forest. In addition, the most predictable Random Forest, Decision Tree, Gradient Boosting, and XGBooost models were applied as individual models, and the Stacking model was constructed using Linear, Ridge, and Lasso models as meta models. As a result of the analysis, the RMSE value in the Ridge model was the lowest at 0.5181, thus building the highest predictive model.

• Korean Journal of Plant Resources
• /
• v.25 no.1
• /
• pp.96-104
• /
• 2012

Phylogenetic analyses were conducted to evaluate relationships of 7 taxa of Korean Carpesium including three outgroup (Inula britannica L., Inula germanica L., Rhanteriopsis lannginosa (DC.) Rauschert) by using ITS (internal transcribed spacer) sequences of nuclear ribosomal DNA. Phylogenetic studies used maximum parsimony, neighbor-joining and maximum likelihood methods analysis. The length of the ITS sequences was 731 bp, and the lengths of the ITS1, ITS2 and 5.8S regions were 284~297 bp, 264~266 bp and 164 bp, respectively. The total number of variable sites was 111 for the entire sequences, and a parsimony informative sites of 64 are valid. Base change appeared variously in ITS1 rather than in ITS2. As the result, Korean Carpesium were formed monophyletic group and C. abrotanoides situated as the most basal clade. The results show that C. macrocephalum is closely related with C. triste. C. rosulatum has the closest relationship with C. glossophyllum. C. cernuum is close to C. divaricatum. These results suggest that the ITS data used in this study could be useful for the phylogenetic analysis of Korean Carpesium.

• Korean Journal of Food Science and Technology
• /
• v.35 no.2
• /
• pp.235-241
• /
• 2003

Yogurt base was prepared from whole and skin milk added with $0.5{\sim}2.0%\;(w/v)$ of cultured ginseng ethanol extract and fermented with lactic acid bacteria (Streptococcos thermophilus : Lactobacillus bulgaricus=1:1) at $37^{\circ}C$ for $24{\sim}30\;h$. Quality characteristics of the yogurt were evaluated in terms of acid production, number of viable cells, viscosity, and sensory property during lactic acid fermentation. Total contents of amino acids and some organic acids were analyzed. Addition of cultured ginseng extract stimulated the growth of lactic acid bacteria, and enhanced acid production and viscosity of yogurt. Total contents of amino acids of 0.5% cultured ginseng-added yogurt were higher than control group before fermentation, whereas glutamic acid, cysteine, valine, and phenyalaine contents increased after 30 h incubation. Contents of lactic, citric, and formic acids of 0.5% cultured ginseng-added yogurt increased during fermentation for 24 h. whereas decreased thereafter. Sensory scores of yogurts added with 0.5 and 1 % cultured ginseng extract were significantly higher than other groups in taste and overall acceptability. When cultured ginseng yogurt was kept at $5^{\circ}C$ for 15 days, its quality-keeping property was relatively good.

• Research in Community and Public Health Nursing
• /
• v.6 no.2
• /
• pp.173-182
• /
• 1995

Primary health care(PHC) has been established since A Health Law for rural residents has been legislated in 1980 following the WHO declaration, 'Health for All 2000'. in 1978. PHC services are presently assumed to be provided by 2038 Community Health Practitioners(CHP) to about 28% out of rural population in Korea. Most CHPs have confronted the adaptation process to the community being practiced although a CHP's role is to evoke community participation for the improvement of their health by themselves. So the purpose of this study is to describe and explain of the commitment of CHPs into the community. Data were collected by direct interview and tape-recording under subjects' permission till theoretical saturation were occured from 6 CHPs. The subjects were 41 years old and have served in the community for 9 years in average. Main questions and concepts were explored from data according to the procedure of the grounded theory methodology. The results are as follows. 1) The number of the main concepts were twenty four that identified Motive, Desire, Personal characteristics, Unfamiliarity, Denial, Feeling of isolation, Self-sacrifice, Kindness, Patience, Assimilation, Respect for the residents, Support by the family, Support by the residents, Achievement, Acceptance of realities, Use of resources, Inducement of cooperation from the residents, Changes of the difference from time orientation between CHP and residents, Attitude as a official, Technical support, Cost management, Satisfaction level, Acknowledgement by the residents and discrepancy. 2) The twenty four concepts were categorized to seven groups such as Motivation, Feeling of Heterogeneity, Self-discipline, Social support, Induced changes in the attitudes of residents, Familarity and Persistent discrepancy. 3) The categorized groups were analyzed on the base of the Causal Conditions, Central Phenomena, Contexts, Intervening Conditions, Action / Interaction Strategies, and Consequences. Central phenomenon in this study was identified to be the feeling of heterogeneity. Community health practitioners experienced unfamiliarity and denial from the community and felt themselves isolated in the first. In time, they won the trust of residents by their efforts including self-sacrifice, kindness, patience, and assimilation. Afterward, practitioners got self-confidence and familiarity with lesser feeling of heterogeneity. Nevertheless, practitioners could not commit themselves completely because of the persistent discrepancy between CHP and residents. 4) On the commitment process, the CHPs' feeling of heterogeneity were decresed and social support increesed and newly evolved induced change of residents through the continuous interaction between CHP and them The contribution of this study would be concluded as follows. 1) It is expected that effective strategies for more rapid committment into the community can be developed based on this study. 2) More easy committment would be possible for the newly appointed CHP through understanding of the committment process identified on this study.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.3
• /
• pp.411-416
• /
• 2002

Yogurt base was prepared from whole milk and skim milk added with 0.2∼1.0% (w/v) of Saururus chinensis(Lour.) Bail water extract (SCe) and fermented with lactic acid bacterias (the mixed strain of Streptococcas themophilus and Lactobacillus bulgaricus) at 37$\^{C}$ for 24 hr. Quality characteristics of the yogurt were evaluated in terms of acid production, number of viable cells, viscosity and sensory property during lactic acid fermentation. The composition of organic acids was also measured by HPLC. Addition of SCe stimulated the growth of lactic acid bacteria and remarkably enhanced the acid production. The viscosity and lactic acid content of yogurt were also increased by addition of SCe. The sensory score of yogurt added with 0.4% of SCe was significantly higher than other groups in taste and overall acceptability The storage abilities of yogurts added with SCe were relatively good at 5$\^{C}$ for 15 days.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.38 no.5
• /
• pp.31-41
• /
• 2010

This research aims to present a methodological approach for repurposing small pockets of national/public lands, which can be constructed as parks, through an investigation of the present status of these areas of national/public lands that are scattered around Busan Megalopolis as well as the suitability of their construction. In order to attain this, this study looked at the present status of these small areas of national/public lands by utilizing a national land, city land list (lot number), land registration map and satellite image of Busan Megalopolis, and evaluating their suitability as parks through GIS analysis and classification. As a result, these small areas of lands with the potential to be turned into parks include 516 spots($375,934m^2$). Geographically, 39% of these areas are located on flat land and are the most scattered. 260 places met the requirements for optimal placement for conversion, while convenience included 305 places, and availability 267 places. The most optimal of the places meeting such standards include 61 spots. The characteristics of these areas of national/public lands include being below $500m^2$, with flatlands and open areas above a 5' grade occupy the highest ratio, accounting for 25.4% of the land studied. These results have offered a methodology for a GIS DB, which can visualize the data for a positive utilization be yond the simple level of the maintenance/preservation of national/public lands and provide basic data for the utilization and management of these types of areas in the future.