• Restorative Dentistry and Endodontics
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• v.32 no.4
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• pp.385-396
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• 2007

The aims of this study were to compare the shaping effect and safety between single length technique recommended by manufacturer and crown-down technique using Mtwo rotary file and to present a modified method in use of Mtwo file. Sixty simulated root canal resin blocks were used. The canals were divided into three groups according to instrument and the manner of using methods. Each group had 20 specimens. Group MT was instrumented with single length technique of Mtwo, group MC was instrumented with crown-down technique of Mtwo and group PT was instrumented with crown-down technique of ProTaper. All of the rotary files used in this study were operated by an electric motor. The scanned canal images of before and after preparation were superimposed. These superimposed images were evaluated at apical 1 to 8 mm levels Angle changes were calculated. The preparation time, weight loss, instrument failure and binding, canal aberrations, and centering ratio were measured. Statistical analysis of the three experimental groups was performed with ANOVA and Duncan's multiple range tests for post-hoc comparison and Fisher's exact test was done for the frequency comparison. In total preparation time, group MT and group MC were less than group PT. In the aberrations, group MT had more elbows than those of group MC and group PT. The binding of group MC was least and group MT was less than group PT (P < 0.05). Under the condition of this study, crown-down technique using Mtwo rotary file is better and safer method than single length technique recommended by the manufacturer.

• Journal of KIISE:Information Networking
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• v.30 no.3
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• pp.329-342
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• 2003

Most of the existing multicast routing protocols for ad-hoc networks do not take into account the efficiency of the protocol for the cases when there are large number of sources in the multicast group, resulting in either large overhead or poor data delivery ratio when the number of sources is large. In this paper, we propose a multicast routing protocol for ad-hoc networks, which particularly considers the scalability of the protocol in terms of the number of sources in the multicast groups. The proposed protocol designates a set of sources as the core sources. Each core source is a root of each tree that reaches all the destinations of the multicast group. The union of these trees constitutes the data delivery mesh, and each of the non-core sources finds the nearest core source in order to delegate its data delivery. For the efficient operation of the proposed protocol, it is important to have an appropriate number of core sources. Having too many of the core sources incurs excessive control and data packet overhead, whereas having too little of them results in a vulnerable and overloaded data delivery mesh. The data delivery mesh is optimally reconfigured through the periodic control message flooding from the core sources, whereas the connectivity of the mesh is maintained by a persistent local mesh recovery mechanism. The simulation results show that the proposed protocol achieves an efficient multicast communication with high data delivery ratio and low communication overhead compared with the other existing multicast routing protocols when there are multiple sources in the multicast group.

• Journal of Soil and Groundwater Environment
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• v.11 no.3
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• pp.31-42
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• 2006

Drought indices, such as PDSI (palmer Drought Severity Index), SWSI (Surface Water Supply Index) and SPI (Standardized Precipitation Index), have been developed to assess and forecast an intensity of drought. To find the applicability of groundwater level data to a drought assessment, a correlation analysis between SPI and groundwater levels was conducted for each time series at a drought season in 2001. The comparative results between SPI and groundwater levels of shallow wells of three national groundwater monitoring stations, Chungju Gageum, Yangpyung Gaegun, and Yeongju Munjeong, show that these two factors are highly correlated. In case of SPI with a duration of 1 month, cross-correlation coefficients between two factors are 0.843 at Chungju Gageum, 0.825 at Yangpyung Gaegun, and 0.737 at Yeongju Munjeong. The time lag between peak values of two factors is nearly zero in case of SPI with a duration of 1 month, which means that groundwater level fluctuation is similar to SPI values. Moreover, in case of SPI with a duration of 3 month, it is found that groundwater level can be a leading indicator to predict the SPI values I week later. Some of the national groundwater monitoring stations can be designated as DIW (Drought Index Well) based on the detailed survey of site characteristics and also new DIWs need to be drilled to assess and forecast the drought in this country.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.1
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• pp.14-19
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• 2007

This study was conducted to analyze the antioxidant activity and xanthine oxidase inhibitory effect of hot-water extracts from Elaeagnus multiflora Thunb. to provide fundamental data for the development of functional materials. The antioxidative activities of hot-water extracts from E. multiflora Thunb. were analyzed by electron donating ability (EDA) using 1,1-diphenyl-2-picryl hydrazyl (DPPH), superoxide dismutase (SOD) -like activity by pyrogallol and nitrite scavenging ability. EDA of extracts from unripe, ripe, and overripe fruits were 77.7%, 36.0%, and 23.7% at 100 ${\mu}g/mL$, respectively, and EDA of extract in unripe fruits was higher than those of others. At 1,000 $\mu$g/mL, the SOD-like activities were 32.8%, 11.2% and 5.0% for unripe, ripe, and overripe fruits, respectively. The SOD-like activity was increased along with the increase of unripe and ripe extract concentrations. The nitrite scavenging ability of unripe fruit extracts in 100, 300, 500 ${\mu}g/mL$ of extraction solution in pH 1.2 and 3.0 was higher than those of others. The nitrate scavenging ability of all extracts was decreased according to the increase of pH. Xanthine oxidase inhibitory activities of unripe, ripe and overripe fruits were 30.0%, 28.2%, and 18.2% at 1,000 ${\mu}g/mL$, respectively.

• Korean Journal of Hospice Care
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• v.8 no.1
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• pp.55-67
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• 2008

Purpose: This study was to test the effects of wholistic hospice nursing intervention program on pain and anxiety for in-patient of hospice palliative care unit. This study's design was one-group pre-post test quasi- experimental research. Methods: The subjects of study were 27 patients who were over 18 years old and admitted in hospice palliative care unit of S hospital in P city with agreement in hospice palliative care in their terminal disease. The experimental group subjects participated in holistic hospice nursing program took 120 minutes per session, a total of 1,200 minutes altogether for 10 sessions. The period of data collection was from April 6, 2004 to April 20, 2005. The collected data were analyzed by Paired t-test with SPSS/WIN 12.0 program. A Wholistic Hospice Nursing Intervention Program (named ‘Rainbow Program’) was used as a experimental tool in this study. This was developed by the authors. It was provided by interdisciplinary hospice team (nurses, medical doctors, social worker, pastors, art therapists, and volunteers). In addition, Korean Version of Brief Pain Inventory (BPI-K) by Young-Ho Yun(1998) was used to test degree of pain in physical aspect. And State-Anxiety Inventory was developed by Spielberger(1975) and translated by Kim, Jung-Tack & Shin, Dong-Gyun(1978) was used to test the degree of state-anxiety in emotional aspect. Results: (1) Hypothesis No. 1 "The experimental group which received Wholistic Hospice Nursing Program will have a lower degree of pain than before" was supported (t=-10.585, P= .000). (2) Hypothesis No. 2 "The experimental group which received Wholistic Hospice Nursing Program will have a lower degree of state-anxiety than before" was supported (t=-8.234, P= .000). Conclusion: Our results testified that this Wholistic Hospice Nursing Intervention Program was effective to decrease pain and state-anxiety of the in-patients of hospice palliative care unit. Therefore it can be used and applied actively in practice as a useful model of interdisciplinary team approach by hospice professionals in hospice palliative care unit.

• Korean Journal of Plant Resources
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• v.17 no.3
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• pp.339-351
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• 2004

This study was conducted to evaluate the effect of phased horticultural therapy(HT) program on the experience of psychologic therapy and the development of job and social integration in the mentally handicapped persons. In this study, the mentally handicapped persons participated in HT program were chosen in disabled person's welfare institute of Jeonnam. HT program was performed twice a week with 1 hour activity for 4 months. As a results, the mentally handicapped persons participated in HT program showed high interest of horticulture and improvement of self-respect and the high satisfactory degree of HT program. Therefore, the mentally handicapped persons were showed the experience of both physical and mental therapy, improvement of self-esteem scale and sociality in HT program. Also, the application of HT program with continuously interest will be showed high improvement of physical, psychological and sentimental. In the course of this HT program progress, horticultural therapist and social welfare officer were showed the limitation of role. Therefore the leaders of group for successful HT program be required the comprehensive plan of more efficient HT program and induced technique of continuously up-phased improvements in HT program progress.

• Journal of Korean Philosophical Society
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• v.116
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• pp.1-31
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• 2010

This Article studies a meaning of geometrical-mathematical spatial idea in the source of modern theories of space. Modern theories of space elucidated a relation of human and space through the geometrical terms; point, line, plane and extension etc. Descartes and Newton identified space as a natural realty, Leibniz and Kant elucidated space as a subjective idea or form. It is the result of modern spatial theories that space is lied nearly in human. In the meaning of natural space, space is empirically unfolded with a shape of measuring in front of human's eyes. In the meaning of cognitional space, space is a method or subjective cognitional form that human understands nature and constitutes world. Modern theories of space would be divided into four patterns. In Newton's theory space is absolutely prior to things. In Leibniz' theory space is a co-existence order of Monads. In Descartes's theory space is identified with extension. In Kant's theory space is cognitional form of subject. They all are confronted with each other in the source of space. In their confrontation they reflected on the relation of human and space in their own standpoint. We classify their particularly differential concepts of space into natural space and cognitional space. And then we analyze a difference of spatial meanings, and then investigate foundations of meaning of modern theories of space. On the one hand they are become to the source of alienation of human from space. But on the other they are contributed to get space familiar with human through a wakening for the correlation of human and space. The natural space indicates that with measurable shape space is extended really in front of human's experiential eyes. But the cognitional space elucidates that space is only a subjective idea or form with which human understands nature and constructs world. In the former it is embossed that space is independent to human, and is able to be measured and to be treated according to natural raws. In the latter it is evidenced that space is not separated to human, and that space is not without human, and a correlation existed between human and space. Humanist ideal is declared in them. It was a declaration of human sovereignty to nature. But this declaration is caused to alienate human beings from space.

• Food Engineering Progress
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• v.15 no.4
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• pp.346-354
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• 2011

This study was carried out to fortify the antimicrobial activity of yoghurt by adding liquorice extract to it. The liquorice extracts (1 mg/mL) showed relatively high antibacterial activity against H. pylori KCCM 40449 (p < 0.05). The solvent liquorice extracts of minimal inhibitory concentrations (MIC) against H. pylori KCCM 40449 were 25- 100 ${\mu}g$/mL. Lactobacillus amylovorus DU-21 with high EPS production ability were inoulated to milk after the addition of different amounts of liquorice extracts (0.0%, 0.05%, 0.1% and 0.2%). The physico-chemical characteristics of yoghurts added with liquorice extracts were examined. The initial pH, titratable acidity, viscosity and viable cell counts of the yoghurt added liquorice extracts were 3.41-3.51, 1.021-1.091%, 1,686-1,930 cp and 9.41-9.38 Log CFU/mL, respectively. The viscosity and syneresis of yoghurt were better than that of the control. Antimicrobial activity against H. pylori KCCM 40449 increased with increasing addition of liquorice extract. However, the sensory score of yoghurt added with different amounts of liquorice extracts was lower than that of the control (p < 0.05). As a result of the sensory evaluations, the flavor, taste, texture, color and overall acceptability of the yoghurt with 0.05% liquorice extract were found to be much better than those of the other groups (p < 0.05). Overall, the optimal amount of liquorice extract added in the manufacture of yoghurt was 0.05% of the total weight. Further studies on increment of antimicrobial activity and palatability of liquorice extract added yoghurt are necessary.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.255-264
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• 2019

In this study, we conducted the hot box tests to compare the changes in thermal insulation for the four types of multi-layer thermal screens by the used period after collecting them from the greenhouses in the field when they were replaced at the end of their usage. The main materials for these four types of multi-layer thermal screens were matt georgette, non-woven fabrics, polyethylene (PE) foam, chemical cotton, etc. These materials were differently combined for each multi-layer thermal screen. We built specimens ($70{\times}70cm$) for each of these multi-layer thermal screens and measured the temperature descending rate, heat transmission coefficient, and thermal resistance for each specimen through the hot box tests. With regard to the material combinations of multi-layer thermal screens, thermal insulation can be increased by applying a multi-layered PE foam. However, it is considered that the multi-layered PE foam significantly less contributes to heat-retaining than chemical wool that forms an air-insulating layer inside multi-layer thermal screens. For the suitable heat-retaining performance of multi-layer thermal screens, basically, materials with the function of forming an air-insulating layer such as chemical cotton should be contained in multi-layer thermal screens. The temperature descending rate, heat transmission coefficient, and thermal resistance of multi-layer thermal screens were appropriately measured through the hot box tests designed in this study. However, in this study, we took into consideration only the four kinds of multi-layer thermal screens due to difficulties in collecting used multi-layer thermal screens. This is the results obtained with relatively few examples and it is the limit of this study. In the future, more cases should be investigated and supplemented through related research.

• Korean Journal of Child Education & Care
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• v.19 no.2
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• pp.177-196
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• 2019

Objective: This study aims to analyze research trends related to software education for young children, focusing on studies published in Korea from 2016 to 2019 March. Methods: A total of 26 research publications on software education for young children, searched from Korea Citation Index and Research Information Sharing Service were identified for the analysis. The trend in these publications was classified and examined respectively by publication dates, types of publications, and the fields of study. To investigate a means of research, the analysis included key topics, types of research methods, and characteristics of the study variables. Results: The results of the analysis show that the number of publications on the topic of software education for young children has increased over the three years, of which most were published as a scholarly journal article. Among the 26 research studies analyzed, 16 (61.5%) are related to the field of early childhood education or child studies. Key topics and target subjects of the most research include the curriculum development of software education for young children or the effectiveness of software education on 4- and 5-year-old children. Most of the analyzed studies are experimental research designs or in the form of literature reviews. The most frequently studied research variable is young children's cognitive characteristics. For the studies that employ educational programs, the use of a physical computing environment is prevalent, and the most frequently used robot as a programming tool is "Albert". The duration of the program implementation varies, ranging from 5 weeks to 48 weeks. In the analyzed research studies, computational thinking is conceptualized as a problem-solving skill that can be improved by software education, and assessed by individual instruments measuring sub-factors of computational thinking. Conclusion/Implications: The present study reveals that, although the number of research publications in software education for young children has increased, the overall sufficiency of the accumulated research data and a variety of research methods are still lacking. An increased interest in software education for young children and more research activities in this area are needed to develop and implement developmentally appropriate software education programs in early childhood settings.