• Restorative Dentistry and Endodontics
• /
• v.34 no.3
• /
• pp.208-214
• /
• 2009

The purpose of this study was to compare the dye leakage of MTA (mineral trioxide aggregate) apical plug produced by two orthograde placement techniques (hand condensation technique and ultrasonically assisted hand condensation technique). To simulate straight canal, 60 transparent acrylic blocks with straight canal were fabricated. These transparent acrylic blocks were divided into 2 groups (Group C; hand condensation technique (HC) and Group U; ultrasonically assisted hand condensation technique (UAHC)) of 30 blocks with each MTA application method. Each group was divided into 2 subgroups (n=15) with different canal size of #70 (subgroup C70 and subgroup U70) and #120 (subgroup C120 and subgroup U120). After apical plug was created, a wet paper point was placed over the MTA plug and specimen was kept in a humid condition at room temperature to allow MTA to set. After 24 hours, remaining canal space was backfilled using Obtura II. All specimens were transferred to floral form socked by 0.2% rhodamine B solution and stored in 100% humidity at room temperature. After 48 hours, resin block specimens were washed and scanned using a scanner. The maximum length of micro leakage was measured from the scanned images of four surfaces of each resin block using Photoshop 6.0. Statistical analysis was performed with Mann-Whitney U test. Group U of UAHC had significantly lower leakage than Group C of HC in #70-size canal (subgroup U70) (p<0.05).

• Journal of Korean Society of Forest Science
• /
• v.106 no.3
• /
• pp.275-287
• /
• 2017

The purpose of this study was to analyze forest vegetation type classification and relationships between the type and environment factor in Mt. Dutasan. Data were collected by total of forty six plots using Z-M phytosociological method from June to October, 2016, and analyzed by vegetation classification, canopy layer structure and relationships between vegetation unit and environment factor using coincidence methods. As a result of vegetation type classification, Quercus mongolica community group was classified at a top level of vegetation hierarchy that was classified into Rhododendron schlippenbachii community and Betula costata community. R. schlippenbachii community was divided into Lychnis cognata group and R. schlippenbachii typical group. L. cognata group was subdivided into Veratrum oxysepalum subgroup and L. cognata typical subgroup. B. costata community was divided into Fraxinus mandshurica group and Betula schmidtii group. F. mandshurica group was subdivided into Weigela subsessilis subgroup and Cimicifuga heracleifolia subgroup. Therefore the forest vegetation was composed of six vegetation units with two kinds of bisected species groups and fourteen species groups. As the result of an analysis of canopy layer structure, there were two kinds of structures with monotonous structures V. oxysepalum subgroup (vegetation units 1), L. cognata typical subgroup (vegetation units 2), W. subsessilis subgroup (vegetation units 4) and complicated structures R. schlippenbachii typical group (vegetation units 3), C. heracleifolia subgroup (vegetation units 5), Betula schmidtii group (vegetation units 6). The vertical layer structure of vegetation unit 5 was the most developed and vegetation unit 6 had the lowest coverage of herb layer. According to the correlation between vegetation unit and environmental factor, R. schlippenbachii community (vegetation units 1~3) and B. costata community (vegetation units 4~6) were classified based on 1,100 m of altitude, middle slope, twenty of slope degree, twenty percents of bare rock and thirty centimeters of DBH in tree layer. R. schlippenbachii community (vegetation units 1~3) showed positive correlation with altitude, topography and B. costata community (vegetation units 4~6) showed negative correlation tendency with them.

• Restorative Dentistry and Endodontics
• /
• v.27 no.5
• /
• pp.521-529
• /
• 2002

The purpose of this study was to compare the shaping time of two shaping methods and the leakage of three different obturation techniques. Ninty three canaled human molar teeth were used, which were randomly divided into two groups of forty teeth each and ten control teeth. After working length determination, the one group was prepared crown-down technique using rotary root canal instruments of GT rotary files .12/20, .10/20, .08/20 and .06/20 taper(Maillefer Instrument SA. Switzerland). The other group was instrumented with Gates Glidden burs(#1, #2, and #3) to coronal preparation and GT rotary files .08/20 and .06/30 taper to apical preparation. Shaping time was measured. After root canals were instrumented, they were divided to three subgroups and obturated as follows : Subgroup 1, obturated with single cone method Subgroup 2, obturated with lateral condensation : Subgroup 3, obturated with continuous wave technique. Three subgroups were obturated using non-standardized gutta-percha cone(Diadent, Korea, .06 or .08 taper) and AH-26(Dentsply DeTrey, Germany) as a root canal cement. Ten unobturated teeth served as positive and negative controls. After immersion in 2% methylene blue solution for 1 month, the teeth were washed during 24h. The teeth were demineralized in 10% nitric acid and dehydrated by immersion in 80, 90 and 100% ethyl alcohol. The teeth were finally cleared and stored in 100% methylsalicylate, and apical dye penetration was evaluated under stereomicroscope(Leica M420, LC, U.S.A)at $\times$8.75 magnification. Liner measurement of dye penetration was assessed with the use of digitalized image analysing system (analySIS, GmbH, Germany) The data were analysed statistically using independent T-test and Two-way ANOVA and Tukey test. The result were as follows 1. In canal prepared with GT$^{TM}$ rotary file, shaphing time taked more than the group of using Gates Glidden drill to coronal preparation without statistical significance (p>0.05) 2. The group of single cone obturation using canal preparation of GT$^{TM}$ rotary files showed significantly more apical leakage than those of lateral condensation and continuous wave technique regardless of shaping method (p<0.05). 3 The group of single cone obturation using canal preparation of GT$^{TM}$ rotary files and Gates Glidden drill showed significantly more apical leakage than those of continuous wave technique regardless of shaping method (p<0.05). 4. Regardless of shaping method, The group of continuous wave obturation showed less apical leakage than those of lateral condensation without statistical significance (p>0.05). 5. The group of single cone obturation using canal preparation of GT$^{TM}$ rotary files and Gates Glidden drill showed more apical leakage than the group of lateral condensation using same shaping method with-out statistical significance (p＞0.05).

• Korean Journal of Clinical Pharmacy
• /
• v.33 no.4
• /
• pp.278-289
• /
• 2023

Background: Linezolid has been widely used in the treatment for multidrug-resistant tuberculosis. However, there are limitations to use it such as long treatment, because of related side effects, even adequate treatment period has been needed for remission of multidrug-resistant tuberculosis (MDR-TB). Method: The meta-analysis was performed based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. To choose literatures, systematic literature reviews were conducted with databases of PubMed, Web of Science, and EMBASE. Results: Efficacy and safety of Linezolid were determined by 85% (95% CI=79~89%, p<0.05) in the sputum culture conversion and 55% (95% CI=45~64%, p<0.01) in side effects related to linezolid, respectively. In addition, I² was estimated by 72%. In the subgroup analysis, efficacy and safety by dose and region were analyzed. In the subgroup analysis, compared with the linezolid dose in groups greater than 600 mg/day and less than 600 mg/day, this study showed 85% (95% CI 79~90%, p>0.05) in 206 patients and 82% (95% CI 73~89%, p<0.05) in 297 patients, respectively. Also, in the subgroup analysis, adverse effects caused by linezolid occurred more than 50% of treated patients. Conclusion: Therapeutic efficacy of linezolid for MDR-TB patients was confirmed regardless of the initial dose of linezolid, especially for sputum culture conversion and it was recommended that the dose of linezolid has been more effective below 600 mg/day. However, it should be necessary to closely monitored for safety issues since serious side effects possibly occurred by administration of long period treatment.

• Journal of Korean Society of Forest Science
• /
• v.80 no.1
• /
• pp.42-53
• /
• 1991

1. The forest vegetation of the Mt. Baek-Hwa situated in the northwestern Kyungsangpookdo of Korea, on $36^{\circ}16^{\prime}00^{{\prime}{\prime}}{\sim}36^{\circ}19^{\prime}20^{{\prime}{\prime}}N$ and 127 53'20"~127 56'30"E was studied by the method of Zurich-Montpellier School. In the present time, the original vegetation have almost been dominated by substitutional communities such as secondary forests of Pinus, Quercus, Zelkova, Acer or Fraxinus and Pinus rzgida plantations. Some secondary forests developing along the ravine and in northwestern part of slope are, however, maintained in natural condition, and contain some species of the original climax vegetation. They are classified as follows : I. Quercus mongolica-Fraxinus siebol diana community(Mountain forests), I-A. Acer pseudo-sieboldianum -Carex okamotoi group, I-B. Pinus densiflora group, I-B-a. Typical subgroup, I-B-b. Rhododendron schlippenbachii subgroup, II. Fraxinus rhynclzophylla-Acer mono community(Valley Forests), II-A. Acer pseudo-sieboldianum group, II-B. Zelkova serrata group, II-B-a. Typical subgroup, II-B-b. Lindera erythrocarpa subgroup, II-C. Querczrs serrata-Platycarya strobilacea group, II-C-a. Typical subgroup, II-C-b. Lindera erythrocarpa subgroup. 2. Judging from the coincidence method, the structure and distribution of the forest communities was more related to topography than altitude. 3. Considering the actual vegetation, relict species, occurrence of natural seedlings and saplings, climate, successional trends of trees and topographic or edaphic climax conditions, it seems that potential natural vegetation of the area mainly composed of Quercus mongolica, Carpinus laxiflora, Zelkova serrata, Fraxinus rhynchophylla. 4. The flora of the vascular plants collected from this area consists of 108 families, 371 genera, 613 species, 2 subspecies, 88 varieties, 6 forms and 709 taxa in total.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.1
• /
• pp.813-821
• /
• 2021

The relationship between capital structure policy and firm value is interesting to study because the concept of capital structure was initiated by Modigliani and Miller who claimed that the company's capital structure is not a factor in its value. They asserted that linking leverage with firm value was irrelevant. Therefore, this study examined the role of growth opportunities as a moderating variable for the relationship between capital structure and firm value. The population of this study is 300 companies from the manufacturing sector that are listed on the Indonesia Stock Exchange (IDX) for the period 2015-2018. To analyze the data, the subgroup moderation method was employed by dividing the data into two parts: companies with high growth opportunities and companies with low growth opportunities. The results revealed that capital structure had a direct positive effect on firm value. Furthermore, the test results of the two regression models of growth opportunities as the moderating variable are very interesting. It was found that for companies with high growth opportunities, the use of debt had a negative effect on firm value, and conversely, the use of debt had a positive effect on firm value for companies with low growth opportunities. The statistical F-test results proved that growth opportunities are a moderating variable for the relationship between capital structure and firm value.

• Journal of Oral Medicine and Pain
• /
• v.18 no.2
• /
• pp.121-130
• /
• 1993

Mandibular rest position is very essential position because in that position, masticatory muscularture can be reciprocally coordinative and unstrained. So obtaining a good ability to establish and maintain rest position in non-functioning state is mandatory for treatment of patient with craniomandibular disorders. In general, many types of mandibulr movement exercise start from rest position and use the sense of muscle relearning, that is, muscle smoothness and relaxation, throughout the exercise period. In this study, 44 normal subjects for control group and 37 patients with craniomandibular disorders for experimental group participated and they were classified into 3 subgroups, respectively. One method to guide mandibular rest position was used for one subgroup, so theree methods were used for this study, 1)self-guided rest position without any education, 2) guided by Rocabado's tongue rest position, 3) guided through swallowing after Dawson's centric relation. To record electromyographic activity, Bioelectric processor EM2 (Myotronics, U.S.A.) was used. The numbers of sessions from start to stable resting electromyographic level and muscle activities in stable state were recorded and two recordings which were first and second, 3 days after first recording, were done, The data were processed with SPSS/PC+package. The obtained results were as follows : 1. Mean number of sessions in second recording were fewer than those in first recording in both groups. In comparison among 3 subgroups, mean number of sessions of subgroup guided through Dawson's method were fewer than those of other groups though it is not statistically significant. 2. There was a difference of mean number of sessions between control and experimental group in first recording, but in second recording there was no difference in any cases. 3. Mean value of muscle activity were generally not different without regard to group and method if once come to stable resting position level. Mean value of muscle activity of guided subgroups showed a tendency of decreasing in second recording than in first recording. However, in self-guided subgroup there was a inconsistent pattern. 4. The amounts of change in session number from first to second recording in control group were fewer than those in experimental group.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.24 no.1
• /
• pp.112-124
• /
• 1997

According to extensive use of composite resin which have superior esthetic property, every effort on improving bonding strength between a tooth and composite resin has been continued. Acid etching technique is a method that micro-etches the tooth surface which provides bonding with composite resin possible. Recently, there were several reports that mechanical treatment obtained from air-abrasion can provide similar bonding strength with acid etching technique. So, this experimental study was designed to compare the shear bonding strength between using air-abrasion technique and using acid etching technique. Initially, bovine teeth were divided into enamel and dentin experimental groups. Respectively each group was categorized into three subgroups. One subgroup was acid etched with 35% phosphoric acid, then bonded with composite resin. The other subgroup was air-abraded with $50{\mu}m$ $Al_2O_3$ particles sprayed with 160psi air pressure using air abrasion unit(KCP-1000, A.D.T., U.SA), and composite resin was bonded. In another subgroup, composite resin was bonded after acid etching following air-abrasion. So, enamel experimental groups were made of E1 (acid etched only), E2(air-abraded only), E3(acid etched following air-abraded), and dentin experimental groups were made of D1(acid etched only), D2(air-abraded only), D3(acid etched following air-abraded). Each subgroup had 10 specimens. Dentin bonding system(Scotchbond Multi-purpose, 3M Co., U.S.A.) and composite resin(Z-100, 3M Co., U.S.A.) were applied on treated surface using 5mm diameter gelatin capsule as manufacturer's direction. After 1200 times thermocycling between $5^{\circ}C$ and $55^{\circ}C$, shear bond strength was measured in 5mm/min crosshead speed with Instron(Instron Co., U.S.A.), and also treated enamel and dentin were observed with SEM(JEOL Co., Japan). The following results were obtained: 1. In the enamel experimental groups, acid etched following air-abraded group had highest shear bond strength, but there was no significant difference compared to acid etched group. Air-abraded only group had lowest shear bond strength, and there was significant difference compared to the rest of groups. 2. In the dentin experimental groups, acid etched following air-abraded group had highest shear bond strength, but there was no significant difference compared to acid etched group. Air-abraded only group had lowest shear bond strength, and there was significant difference compared to the rest of groups. 3. In the SEM study, air-abraded enamel and dentin had irregular and rough surfaces.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 2000.04a
• /
• pp.475-478
• /
• 2000

Recently encryption algorithms based on difficulties of factorization have been used with popularization. Prime number factorizations are progressed rapidly. In this paper, characteristics of elliptic curve are analyzed and generation of elliptic curves suitable for prime number factorization is discussed.

• Bulletin of the Korean Mathematical Society
• /
• v.43 no.1
• /
• pp.119-123
• /
• 2006

Let G be a symmetric group. In this paper we describe a method that for a certain irreducible character X of G it finds a subgroup H such that the restriction of X on H has a linear constituent with multiplicity one. Then using a well known algorithm we can construct a representation of G affording X.