• Title/Summary/Keyword: Frequency effect

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Comparison of shaping ability between single length technique and crown-down technique using Mtwo rotary file (Mtwo 전동 파일을 사용한 single length technique과 crown-down technique의 근관성형 효율 비교)

  • Lim, Yoo-Kyoung;Park, Jeong-Kil;Hur, Bock;Kim, Hyeon-Cheol
    • 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.

A Study on Operation Strategy by Multi-variate Regression of Deagu Arboretum Visitor's Satisfaction (대구수목원 이용객 만족모델을 통한 운영 방안 연구)

  • Kang, Kee-Rae
    • Journal of Korean Society of Forest Science
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    • v.101 no.1
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    • pp.36-45
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    • 2012
  • Education on the environment and plants offered by arboretum for today's people not only contribute to foster a better natural environment in urban region but also provide visitors with decent refreshment environment and beyond. In the study, the author undertook the observation on usage behavior and satisfaction model of arboretum visitors expect and investigated the facilities and programs to be offered by arboretum in order to propose the opinion regarding the service. For observation size of variables in a multiple regression analysis of variables is influencing satisfaction rankings walks the line of flow, the educational effect on the environment, cleanliness of the facility, visits pay, natural beauty, diversity of trees, accessibility and friendliness of staff, expansion of facilities in the arboretum and appeared as a complement. In case of visitor attribute, the residents living near the facility showed the highest visit frequency of more than 5 times, especially as part of taking a walk. This proves that the visit to arboretum is considered as part of everyday life, and thus a new program and walk path as well as movement route are needed to be developed for the visitors. In the question relating to the facilities and operation programs in Daegu Arboretum, particularly the requests by visitors, they responded that the establishment of cultural event, beautiful natural scenery, refreshment and convenience facilities is the most critical issue. In addition, the management on withered trees and bare lands is an urgent issue as well. In this sense, the Operation and Management Strategies based upon the visitor behaviors and model of satisfaction are needed to deal with the adoption of diverse events and festivals joined by local residents, ombudsman program, environmental program development for students and teachers within the region, negligent bare lands and withered tree replacement, and cafeteria facility improvement and supplement as well as the bench marking of other facilities than arboretums located in other regions. These items are thought to be sufficiently dealt with by Daegu Arboretum having no more external resources. It is recognized that the visitor satisfaction begins from a minor thing, and a small difference determines a great satisfaction, and thus the software approach rather than hardware one is in need.

The Effects of Social Class on the Leisure Activities in Korea: based on types and satisfaction of leisure activities (사회계층 변수에 따른 여가 격차 : 여가 유형과 여가 및 삶의 만족도를 중심으로)

  • Nam, Eun-Young;Choi, Yu-Jung
    • Korea journal of population studies
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    • v.31 no.3
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    • pp.57-84
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    • 2008
  • This study investigates the patterns of leisure in Korea and the effects of social class on the objective and subjective dimension of leisure activities and life satisfaction. A data set of 1376 Korean men and women over 18 years old is analyzed to yield five main results. First, Korean prefers domestic entertainment to outdoor activities as is exemplified by domestic audio-visual entertainment(TV/DVD/VCR) which ranks the highest in the favored leisure activity. Leisure activities are divided into four types; "activity-based", "relationship-based", "alcohol-based", "relaxation". Second, the function of leisure activity is to strengthen relationships. The main purpose of leisure activity is to relax and revitalize, while creating prospective social network ranks next to relax. But the effect of leisure time is often compromised by recurring thoughts related to work. Third, respondents with high educational and economic backgrounds are more likely to engage in "relationship-based," "activity-based", "alcohol-based" leisure type. However, such factors do not influence on "relaxation" type of leisure. While students and housewives rank highest in number of respondents, respondents with managerial/professional or white-collar/semi-professional occupations enjoy more diverse activities. Fourth, the effort to discern the significance of social class with respect to the leisure-activity-index revealed followings; the index scores elevate with higher education, younger age and higher income. Fifth, leisure-activity-index is the most important variable predicting leisure satisfaction. Leisure satisfaction is influenced by gender, age, income and occupation. The younger the age and higher the income, the higher it is the leisure satisfaction. Men are more satisfied with leisure activities than women. Students experience the highest satisfaction with leisure activities while service/sales workers, industrial/technical/blue-collar workers shows the least satisfaction. Also, the number of family members decreases significantly the leisure satisfaction. While "activity-based" leisure induces the highest satisfaction, "alcohol-based" leisure produces the least satisfaction. The frequency and diversity of leisure activities, and "activity-based" leisure incur the most positive effects on the life satisfaction.

Effect of Magnesium Administration on Preventing Arrhythmias after Coronary Artery Bypass Graft (관상동맥 우회술 후 마그네슘 투여가 심 부정맥을 예방하는 효과)

  • Kim, Jun-Hyun;Song, Hyun;Kim, Yong-Hee;Lee, Eun-Sang;Lee, Jay-Won;Song, Myung-Kun
    • Journal of Chest Surgery
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    • v.31 no.4
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    • pp.339-345
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    • 1998
  • Arrhythmias are common after cardiac surgery and are multifactorial. Intravenous magnesium administration reduces the frequency of ventricular arrhythmias in patient with symptomatic heart failure or acute myocardial infarction. This study was designed to evaluate the role of magnesium in preventing PVCs(premature ventricular contractions) occurred frequently after coronary artery bypass graft(CABG). 50 consecutive patients were prospectively entered into a randomized trial to determine the efficacy of postoperative magnesium therapy on the incidence of cardiac arrhythmias after elective coronary artery bypass graft. The patients underwent coronary angiography, echocardiography, electrocardiography and clinical laboratory study preoperatively. Continuous electrocardiographic monitoring was done and magnesium level was checked 0, 3, 6, 12, 18, 24, 36, 48, 60 and 72 hours postoperatively. Study group of 25 patients were given 4g of magnesium continuously over the first 24 hours and then 2g/24hours from 25 to 72 hours. The clinical characteristics of both groups were similar(p<0.05). The preoperative mean serum magnesium concentration was similar in both study group, 1.59mg/dl and control group, 1.71mg/dl. The mean postoperative serum magnesium concentration in study group elevated significantly over postoperative 12hours through 36hours(p<0.05). The postoperative mean serum magnesium concentration in control group declined and remained significantly depressed over immediate postoperation through 72hours. The mean serum magnesium concentration was significantly greater in the study group compared with the control group over postoperative 3hours through 72hours(p<0.05). There was a significant decrease in the incidence of arrhythmias such as PVCs(p<0.01) which might jeopardize hemodynamics. There were no recognized adverse effects of magnesium Administration. In conclusion, prophylactic magnesium administration seems to lessen the incidence and severity of rrhythmias after coponary artery bypass graft.

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Effects of Growth Regulators, Sucrose and Gelling Agents on Callus Growth and Plant Regeneration in Angelica koreana MAX. (강활(羌活)의 캘러스 증식(增殖) 및 식물체(植物體) 재분화(再分化)에 미치는 생장(生長) 조절제(調節劑), sucrose 및 배지(培地) 응고제(凝固劑)의 영향(影響))

  • Lee, Joong-Ho;Lee, Seung-Yeob;Namkoong, Seung-Bak
    • Korean Journal of Medicinal Crop Science
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    • v.4 no.1
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    • pp.78-85
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    • 1996
  • The effects of growth regulators, sucrose and gelling agents were investigated to increase the efficiency of the callus growth and plant regenerarion in tissue culture of Angelica koreana Max. The fresh weight and dry weight of subcultured callus was highest in MS medium supplemented with 1 mg/l 2,4-D. Callus growth was excellent in 2% sucrose, but it was inhibited in propotion to sucrose content. Effect of gelling agents on callus growth was highest on 1.2% agar and 0.4% Gelrite medium, respectively. The browning of callus was protected on the media supplemented with 10 mg/l ABA and 5 or 10 mg/l $AgNO_3$. In the callus induction and growth from the peduncle of immature inflorescence, 2,4-D was more effective than NAA, and the frequency of callus induction was highest as 81.7% in 2 mg/l 2,4-D. Plant was not regenerated from the callus derived from young leaf. Somatic embryos were developed from the surface of callus drived from the peduncle of immature inflorescence in the medium containing 0.5 mg/l 2,4-D, 1 mg/l kinetin, 5 mg/l ABA and 5 mg/l $AgNO_3$. Plants were developed from the matured somatic embryos in the medium supplemented with 0.2 mg/l 2,4-D and 1 mg/l kinetin.

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The Effect of Radiation Therapy on hemophilic Athropathy (혈우병성 관절증에 대한 방사선 치료의 역할)

  • Kang Jin Oh;Hong Seong Eon;Kim Sang Gi;Shin Dong Oh
    • Radiation Oncology Journal
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    • v.23 no.2
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    • pp.106-110
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    • 2005
  • Purpose : Repetitive bleeding into the joint space is the cause of debilitative hemophilic arthropathy. To interrupt this process, we treated the hemophilic patients suffering from repetitive joint bleeding with radiation therapy. Materials and Methods : From 1997 to 2001, a total of 41 joints from 37 hemophilic arthropathy patients were treated with radiation therapy at Kyung Hee University Hospital. The treated joints were 35 ankles, 3 knees and 3 elbows, respectively. The age of the patients ranged from 4 to 27 years (median age: 11 years). The radiation dose ranged from 900 cGy to 2360 cGy (median dose: 900cGy). The fraction size was 150 cGy, 180 cGy or 200 cGy. The number of bleeding in one year before and after radiotherapy was compared. Results : There was a tendency of frequent bleeding for the Patients younger than 11 (p=0.051) but there was also a tendency for more improvement in this group (p=0.057). The number of joint bleedings was related with joint pain (p=0.012) and joint swelling (p=0.033) but not with the Arbold-Hilgartner stage (p=0.739), cartilage destruction (p=0.718) and synovial hypertrophy (p=0.079). The number of bleeding was reduced in thirty-three cases, and eight cases showed no improvement after radiation therapy. The average number of bleeding in a month was 2.52 before radiotherapy, but this was reduced to 1.4 after radiotherapy (p=0.017). Conclusion : Radiation therapy was effective for the hemophilia patients with repetitive joint bleeding to decrease the bleeding frequency and to prevent hemophilic arthropathy.

Comparison of Raw versus Relative scores in the Assessment of Coping Patterns in Chronic Arthritis Patients (만성관절염 환자의 대응양상정도와 관련변수 분석 -원점수와 상대점수를 이용한 비교-)

  • Chun, Chung-Ja;Mun, Mi-Suk
    • Journal of muscle and joint health
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    • v.3 no.1
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    • pp.90-103
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    • 1996
  • The purpose of this paper is to compare two approach to assessment of coping patterns. The sampling method was a purposive sampling technique. The study participants were out patients 113 of rheumatoid arthritis center of one University hospitals in Seoul. Datas were collected from Nov. 13 to Nov. 24, 1995. The instruments used for this study were Graphic Rating Scales of pain, The Beck Depression Inventory and Coping Patterns tool. The collected data were analyzed for frequency, means, SD, factor analysis., Pearsons' correlations and ANOVA. The results were summerized as follows ; 1. When raw scores were used : there were not correlation in all three coping patterns. 2. When relative scores were used : there were significantly correlated in all three coping patterns. 1) Active coping and Positive-cognitive coping (r=-0.352, p< 0.0001) 2) Positive-cognitive coping and Negative-cognitive coping (r=-0.594, p< 0.0001) 3) Active coping and Negative-cognitive coping(r=-0.544, p< 0.0001) The results of this research with relative scales provided more insight into the correlation in all three coping patterns. 3. Pearsons' Correlations were computed for each coping pattern, age, pain level, duration of pain and BDI. 1) Using raw score : (1) Active coping was significantly related to pain level(sensory score ; r=0.268, p<0.05, affective score ; r=0.266, p< 0.05) (2) Positive-cognitive coping was significantly related to age (r=-0.252, p< 0.05), pain level (sensory score ; r= -0.244, p< 0.05) (3) Negative-cognitive coping was significantly related to depression level (r=0.312 p< 0.0001). 2) Using relative score (1) Active coping was significantly related to pain level(sensory score ; r=0.299, p<0.05, affective score ; r=0.246, p< 0.05) (2) Positive-cognitive coping was significantly related to age (r= -0.187, P< 0.05), pain level (sensory score ; r=-0.317, p<0.0001, affective score : r=-0.305, p<0.0001) and depression level(-0.339, p<0.0001)) (3) Negative-cognitive coping was significantly related to depression. level(r=0.313, p<0.0001). 4. When raw and realtive coping scores were compared to those of age groups, religious groups and BDI level(high, middle, low) ; 1) Using raw score : (1) Active coping : there were not significantly difference (2) Positive-cognitive coping ; 20-39 age group and 50-59age group had significantly higher scores than over 60age group. BDI-low level group had significantly higher scores than other groups. (3) Negative-cognitive coping : 20-39age group and over 60age group had significantly higher scores than 40-49age group. Non-religious group had significantly higher scores than christian group. BDI-high level group had significantly higher scores than other groups. 2) Using relative score : (1) Active coping : over 60 age group had significantly higher scores than 20-39 age group and 40-49age group had significantly higher scores than 20-39 age group (2) Positive-cognitive coping ; 40-49age group, 20-39age group and 50-59age group had significantly higher scores than over 60age group. Christian group had significantly higher scores than non-religious group. BDI-low level group had significantly higher scores than other groups. (3) Negative-cognitive coping ; Non-religious group had significantly higher scores than christian group and buddhistic group. BDI-high level group had significantly higher scores than other groups. The current data suggest that relative scores may yield a different perspective on coping patters than raw scores. The use of relative scores reveals the relation clearly, without its being blurred statistically by the effect of other coping strategies or being relegated to a partial correlation. The use of relative scores holds promise for delineating the relations between ways of coping and health-related behavior.

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Temporal and Spatial Variability of Phytoplankton Communities in the Nakdong River Estuary and Coastal Area, 2011-2012 (2011-2012년 낙동강 하구 및 연안역에서 식물플랑크톤 군집의 시·공간적 변화)

  • Chung, Mi Hee;Youn, Seok-Hyun
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.18 no.4
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    • pp.214-226
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    • 2013
  • To understand the changing patterns in phytoplankton communities, we conducted 12 surveys along the Nakdong River, its estuary, and adjacent coastal areas between January 2011 and October 2012 (during the period of barrage construction and sediment dredging). Monthly precipitation ranged from 0 to 502 mm during the survey period, and salinity ranged between 0.1 psu and 0.3 psu in the Nakdong River, regardless of the depth, indicating no seawater influence, while salinity showed large seasonal fluctuations in the estuarine and coastal station, ranging from 0.1 psu to 34.8 psu. A total of 402 phytoplankton species were identified, 178 species from the river and 331 species from the estuary and coastal areas. Phytoplankton standing crop increased in 2012 compared to that in 2011, and was found to be highest in the river, followed by the estuary and coastal areas. Among the top 20 species in frequency of occurrence and dominance, Stephanodiscus spp., Aulacoseira granulata, and Aulacoseira granulata var. angustissima and Pseudo-nitzschia spp. were important species along the river-estuary-coastal areas. Diatoms were the major taxonomic group inhabiting the Nakdong river-estuary-coastal areas. A comparison of seasonal dominant phytoplankton species revealed a slight decrease over the years, from 13 species in 2011 to 10 species in 2012. However, no significant difference was found in the diversity of phytoplankton species between the two survey years, although lightly greater diversity was observed in the coastal areas than in the river and estuary. Cluster analysis with community composition data revealed that the community structure varied significantly in 2011 depending on the time of survey, while in 2012, it hardly showed any variation and was simpler. An increase in the phytoplankton standing crop, fewer dominant species, and simpler community structure in 2012 compared to those in 2011 are probably due to the rapid environmental changes along the Nakdong River. To investigate these ecological relationships, it is necessary to conduct further studies focusing on integrated analyses of biocenosis, including phytoplankton with respect to the changes in nutrient distribution, variation of freshwater discharge, and effect area of freshwater in the Nakdong estuary and adjacent coastal areas.

A Study on Characters of Select Behaviors of Tourist - at a spa & resort - (관광객의 선택행동 특성에 관한 연구 - 온천리조트를 중심으로 -)

  • Oh, Jae-kyung
    • Journal of Distribution Science
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    • v.4 no.2
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    • pp.81-106
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    • 2006
  • The value of Its visitors is very important factors on selection of a Spa & Resort. The first detailed purpose of this paper is to analyse the differences of select behaviors of a Spa & Resort according to the types of values of the visitors. The second aim is to conduct a research on the characters of select behaviors of the visitors. The third aim is to analyse the degree of satisfaction of the visitors, re-visitation and the intention of recommendation. The fourth purpose is to provide useful materials on analysis about the values of the visitors at various Spa & Resorts and to trigger dramatic effect of recuperation, relaxation with its visitor's needs met, the maximum of hotel's management profit at Spa & Resort's area and programs to activate the region's economy. Factor Analsis Routine of SPSS Windows Version 10.0 was applied to accomplish the issues of the study. The Applied analysis by research process are as follows; This paper applied Frequency analysis to figure out interviewee's demographic characters and various using types of the visitors, using their experience of visiting, Select influence, Visiting period, Accommodation they use, Accompanyist, Costs, Season, Transportation, The necessary time. This paper showed important correlation between the visitors' select attributes and behaviors after using it, between their personal value and behaviors after using it, between their individual value, motive of use and their select behavior of destinations. In accordance with it, Managers or developer of a Spa & Resort should make a plan after a sufficient review of the visitors' individual value. The visitor's value is changing continuously according to the change of spatial, occasional environment and should be assessed by those changes.

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Antibacterial Activity of Ceftizoxime Against Gram Negative Enteric Bacteria in vitro and in vivo (Ceftizoxime의 장내세균에 대한 시험관내 및 생체내 항균효과)

  • Byun, Woo-Mok;Chang, Jae-Chun;Park, Bok-Hwan;Kim, Hee-Sun;Kim, Sung-Kwang
    • Journal of Yeungnam Medical Science
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    • v.6 no.1
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    • pp.59-68
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    • 1989
  • Ceftizoxime sodium is a new synthetic ${\beta}$-lactam antibiotic combining potent antibacterial activity with high stability to a wide range of bacterial ${\beta}$-lactamase. This experiment was achieved to evaluate the antibacterial activities of ceftizoxime sodium againist Gram negative enteric bacteria isolated from in outpatient visiting Yeungnam university hospital and to study the emergence of drug induced bacterial varients which resist to ceftizoxime in vitro. The antibacterial activity of the ceftizoxime was compared with that of antibiotics and its effect on population of normal intestinal flora in mice was observed. The results are summarized as follows : 1. Highly effective antibacterial activity of ceftizoxime against Gram negative enteric bacilli was demonstrated and this antibacterial activity was superior to that of ampicillin. 2. Several test strains shows multiple antibiotic resistence. Among 15 strains of Escherichia coli, 1 strain was resistent to ampicillin, cefadroxyl, gentamicin, tetracycline, and 2 strains were resistent to ampicillin, cefadroxyl, tetracycline, five strains of Escherichia coli and Enterobacter cloacae was resistent to amplicillin, tetracycline and Shigella dysenteria was resistent to ampicillin, gentamicin, tetracycline. 3. The frequency of in vitro emergence of resistent varients among ceftizoxime sensitive bacteria in the presence of increasing concentrations of the compound was found to be low. 4. Plasmid was isolated in 6 of 9 strains (6 strains of Escherichia coli, Shigella dysenteriae, Enterobacter cloaceae and Salmonella typhi) That showed different antibiotic resistance. They were 5 strains of Escherichia coli and 1 strain of Shigella dysenteriae. However, plasmid could not be considered as a hallmark for antibiotic resistance by this. Further studies with curing experiment are to be accomplished for this purpose. 5. Changes in the bacterial count of normal intestinal flora following 25mg/kg/day administration of ceftizoxime over S consecutive days were not significant. In conclusion, ceftizoxime appeared to be a drug of choice in the treatment of Gram negative enteric bacilli infection.

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