• Journal of Periodontal and Implant Science
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• v.45 no.2
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• pp.46-55
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• 2015

Purpose: This study evaluated the mechanical and structural properties of biphasic calcium phosphate (BCP) blocks processed using a modified extrusion method, and assessed their in vivo effectiveness using a rabbit calvarial defect model. Methods: BCP blocks with three distinct ratios of hydroxyapatite (HA):tricalcium phosphate (TCP) were produced using a modified extrusion method:HA8 (8%:92%), HA48 (48%:52%), and HA80 (80%:20%). The blocks were examined using scanning electron microscopy, X-ray diffractometry, and a universal test machine. Four circular defects 8 mm in diameter were made in 12 rabbits. One defect in each animal served as a control, and the other three defects received the BCP blocks. The rabbits were sacrificed at either two weeks (n=6) or eight weeks (n=6) postoperatively. Results: The pore size, porosity, and compressive strength of the three types of bone block were $140-170{\mu}m$, >70%, and 4-9 MPa, respectively. Histologic and histomorphometric observations revealed that the augmented space was well maintained, but limited bone formation was observed around the defect base and defect margins. No significant differences were found in the amount of new bone formation, graft material resorption, or bone infiltration among the three types of BCP block at either of the postoperative healing points. Conclusions: Block bone substitutes with three distinct compositions (i.e., HA:TCP ratios) processed by a modified extrusion method exhibited limited osteoconductive potency, but excellent space-maintaining capability. Further investigations are required to improve the processing method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.3
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• pp.311-318
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• 2015

A nonlinear dynamic response structural optimization process is proposed for the television (TV) packing system that protects the damage from a drop situation using the equivalent static loads (ESLs). Topology optimization using ESLs is carried out for conceptual design, and shape optimization using stress ESLs for a virtual model is performed for detailed design. Stress ESLs are static loads that generate the same displacement as well as the stress fields of linear static analysis as those of nonlinear dynamic analysis. Thus, the response of nonlinear dynamic analysis can be utilized as a constraint in the linear static structural optimization. An actual example is solved to validate the process. The drop test of a television packaging system is analyzed by LS-DYNA, and NASTRAN is used for optimization.

• The Plant Pathology Journal
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• v.25 no.4
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• pp.322-327
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• 2009

A total of 23 isolates of Botrytis cinerea causing the grey mold were collected from infected ginseng in several fields of Korea. The sensitivity to carbendazim and the mixture of carbendazim plus diethofencarb was determined through a mycelial inhibition test on PDA amended with or without fungicides. B. cinerea isolates were classified as 3 phenotypes, which were the first phenotype resistant to both of carbendazim and the mixture ($Car^RMix^R$), the second one resistant to carbendazim and sensitive to the mixture ($Car^RMix^S$), and the last one sensitive to both of them ($Car^RMix^S$). Carbendazim resistance correlated with a single mutation $\beta$-tubulin gene of B. cinerea amplified with primer pair tubkjhL and tubkjhR causing a change of glutamate to alanine at amino acid position 198. Furthermore, the substitution of valine for glutamate led the resistance to carbendazim and the mixture at the same position of amino acid. PCR-restriction fragment length polymorphism (PCR-RFLP) analysis using the restriction endonuclease, Tsp451 and BstUI allowed differentiation of the PCR fragment of $\beta$-tubulin gene of $Car^SMix^S$ isolates from that of $Car^RMix^R$ and $Car^RMix^S$ isolates. This method will aid in a fast detection of resistance of carbendazim and the mixture of carbendazim plus diethofencarb in B. cinerea in ginseng field.

• Journal of Korean society of Dental Hygiene
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• v.11 no.1
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• pp.81-94
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• 2011

Objectives : This study conducted to investigate oral care abilities in diabetic patients to find a good dental method which may efficiently control diabetes. Methods : The diabetic group consisted of 40 patients with type 2 diabetics, while the non-diabetes were 34 persons with no signs of diabetics, who had visited a Public Health Center and dental clinic of a general hospital in Gwangju city from Dec. 2008 to Sep. 2009. Periodontal disease, gingivitis, dental caries, tongue plaque and halitosis between diabetic group and non-diabetic group were examined and at the same time a questionnaire survey was conducted. The data were analyzed with chi-square, t-test, pearson correlation coefficients using the SPSS WIN 15.0 program. Results : The mean values of both the community periodontal index and the gingival index of diabetic group were 2.18 and 1.75, respectively, and those were higher than those (1.79 and 1.50) of non-diabetic group with no statistical significance. The mean saliva secretion of non-diabetics was 16.74 mL, which was higher than 13.90 mL of diabetic patients(p<0.05). The oral care ability(mean 3.10) acquired from plague index in diabetic group was worse than in non-diabetic(mean 2.33). Conclusions : The high blood sugar concentration in diabetic patients causes low saliva secretion and high saliva viscosity, with the results halitosis and periodontal disease take place. This study suggested that good oral care ability of diabetic patients was very helpful to prevent periodontal disease and halitosis. In addition to this, it may reduce complications of diabetic patients.

• Archives of design research
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• v.18 no.1 s.59
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• pp.185-194
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• 2005

The objectives of this research are to examine the relationships among designers' characteristics, mutual communication, conflicts between CI designer and client, to test the impacts of conflicts and four type of resolution strategies on the performance of CI development, and to recommend proper strategies for successful CI process and output management. The survey results show as follows. First, CI designers' confidentiality on clients' internal information and creative designing ability were found to affect mutual communication between them. Second, proper communication was found to lessen the conflict level which in turn yielded the positive performance of CI development, especially for the clients' side. Third, it is suggested that the conflict level be first reduced and conflict resolution strategies be applied depending upon the conflict level and related party of designer or client position, respectively.

• Physical Therapy Korea
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• v.23 no.4
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• pp.55-62
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• 2016

Background: The functioning of the serratus anterior (SA) muscle is essential to normal scapulohumeral rhythm during forward flexion (FF) of the shoulder. Also, SA weakness and overuse of the upper trapezius (UT) is observed in patients with shoulder dysfunction and trapezius myalgia. We designed a combination exercise involving FF and scapular protraction with resistance (CFFSP) to activate the SA muscle and to deactivate the UT muscle. Objects: The purpose of this study was to determine whether or not CFFSP would be more effective in activating the SA muscle than FF alone and FF with scapular protraction (FFP). Methods: Nineteen subjects (12 men and 7 women) participated in this study and performed FF, FFP, and CFFSP at $120^{\circ}$. Surface electromyography was applied to the SA, UT, and pectoralis major (PM) muscles, as was one-way analysis of variance (ANOVA) with repeated measures. Statistical significance was set at .05. Bonferroni adjustment was used to counteract the problem of multiple comparisons, with a statistical level of significance of .017 (.05/3). Results: A statistically significant difference was found in relation to the three positions for the SA muscle (p<.001) and the SA/UT ratio (p=.005) using ANOVA. Significantly different results, depending on the position, were also demonstrated using the Bonferroni post-hoc test for the SA muscle ($FF=28.27{\pm}16.20$, $FFP=45.66{\pm}15.81$, and $CFFSP=62.4{\pm}27.21$) and for the SA/UT ratio ($FF=3.04{\pm}2.14$, $FFP=3.61{\pm}2.38$, and $CFFSP=5.95{\pm}3.01$). Significant differences between the three positions was not found regarding the average amplitude of SA/PM muscle ratio (SA/PM: p=.060). Conclusion: We recommend the use of CFFSP to strengthen the SA muscle at $120^{\circ}$.

• Journal of Ecology and Environment
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• v.35 no.2
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• pp.91-98
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• 2012

This study was performed in order to suggest the possibility of tree species classification using high-resolution QuickBird-2 images spectral characteristics comparison(digital numbers [DNs]) of tree species, tree species classification, and accuracy verification. In October 2010, the tree species of three conifers and eight broad-leaved trees were examined in the areas studied. The spectral characteristics of each species were observed, and the study area was classified by image classification. The results were as follows: Panchromatic and multi-spectral band 4 was found to be useful for tree species classification. DNs values of conifers were lower than broad-leaved trees. Vegetation indices such as normalized difference vegetation index (NDVI), soil brightness index (SBI), green vegetation index (GVI) and Biband showed similar patterns to band 4 and panchromatic (PAN); Tukey's multiple comparison test was significant among tree species. However, tree species within the same genus, such as $Pinus$ $densiflora-P.$ $rigida$ and $Quercus$ $mongolica-Q.$ $serrata$, showed similar DNs patterns and, therefore, supervised classification results were difficult to distinguish within the same genus; Random selection of validation pixels showed an overall classification accuracy of 74.1% and Kappa coefficient was 70.6%. The classification accuracy of $Pterocarya$ $stenoptera$, 89.5%, was found to be the highest. The classification accuracy of broad-leaved trees was lower than expected, ranging from 47.9% to 88.9%. $P.$ $densiflora-P.$ $rigida$ and $Q.$ $mongolica-Q.$ $serrata$ were classified as the same species because they did not show significant differences in terms of spectral patterns.

• Physical Therapy Korea
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• v.27 no.4
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• pp.272-277
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• 2020

Background: Forward head posture (FHP) is common postural malalignment. FHP is described relatively extension to upper cervical and lower cervical is relatively flexion. Although several researchers mentioned the lower cervical flexion posture in FHP, most of the studies related to FHP is focused on the deep cervical flexor function. Objects: The purposes of present study is to compare the cervical strength (upper cervical extension [UCE], lower cervical extension [LCE], upper cervical flexion [UCF], lower cervical flexion [LCF]) between individuals with and without FHP. Methods: Fifty-one participants are recruited. Participants who have the craniovertebral angle (CVA) less than 48 degree were classified to the FHP group (n = 24) and the others were included in without FHP group (n = 27). The cervical strength (UCE, LCE, UCF, LCF) were measured using Smart KEMA strength sensor and the strength data was normalized by body weight. All strength measurement conducted at head and neck neutral position in sitting. Independent t-test was used to compare the cervical strength between individuals with and without FHP. Results: The mean value of CVA was greater in without FHP group than with FHP group (p < 0.000). The strength value of UCF (p < 0.002) and LCE (p < 0.001) was significant less in FHP group than without FHP group. But no significant differences were seen in the LCF and UCE strength between two groups. Conclusion: UCF and LCE weakness in FHP group should be considered to evaluate and manage the individuals with FHP.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.8
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• pp.94-103
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• 2020

This study investigated the effects of ultrasonic nanocrystal surface modification (UNSM) on the deteriorated surface of AISI SUS316L additively manufactured (AM) using the powder bed fusion (PBF) technique. Specifically, the effects of UNSM conditions on surface topology, hardness, and anti-corrosion were examined. Before UNSM treatment, the stainless steel 316L powder was processed via the PBF machine to prepare a substrate. We observed surface changes due to UNSM treatments in PBF SUS316L substrates and examined the correlation between topology changes, roughness, hardness, and anti-corrosion. After UNSM treatment, the coarse as-built surface was refined, and a regular micro-profile was implemented. Compared to the non-treated PBF sample, the waviness and roughness of the surfaces after UNSM treatment decreased by up to 56.0% and 94.5%, respectively, and decreased further as the interval decreased. The hardness improved by up to 63.0% at a maximum depth of 500 ㎛ from top surface by the UNSM treatment. The results of the corrosion test showed that the corrosion resistance of the UNSM specimens was moderately improved compared to that of the untreated surface. This study confirmed that UNSM is an effective post-processing technique for additively manufactured parts.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.25 no.4 s.34
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• pp.111-121
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• 1999

Acne vulgaris, the most common skin disease. can be formed as only a few comedons or severe inflammatory lesions. The pathogenesis of acne involves various factors; excessive androgen, excessive sebum production, abnormal alteration of follicular epithelium, proliferation of Propionibacterium acnes, and inflammation. We investigated acne therapy using oriental herbs described in the Korean traditional medical book(Dong-ui-bo-gam). Oriental herbs(Angelica daurica, Arctium lappa, Coptidis rhizoma, and Glycyrrhiza glabra) were chosen based on their respective property of sebum control, anti-inflammatory activity, and anti-bacterial activity. We examined the effect of acne treatment, in terms of chemotactic inhibition, lipogenesis inhibition, and anti-bacterial activity for P. acnes. 1. Neutrophil chemotaxis assay; P. acnes secrete chemotactic factors and other pro-inflammatory extracellular products. Neutrophil chemotactic activity of P. acnes was measured by 48-well chemotaxis method. Angelica daurica clearly suppressed chemotactic activity of P. acnes. 2. Using sebaceous gland of hamster ear lipogenesis assay; Sebaceous lipogenesis was measured using ear biopsies by incubation or $C^{14}$-acetate in culture media. The $C^{14}$-labeled lipids were extracted and determined by liquid scintilation counting. Coptidis rhizoma markedly inhibited sebum production. 3. Anti-bacterial assay for P. acnes(MIC test); Glycyrrhiza glabra showed anti-bacterial activity. P. acnes did not develop resistance against Glycyrrhiza glabra. Retinoids are effectively to inhibit sebum production and regulate follicular keratinization process, with little anti-inflammatory activity. Angelica daurica suppressed neutrophil chemotaxis, Coptidis rhizoma inhibited sebum production, and Glycyrrhiza glabra showed anti-bacterial activity against P. acnes. A combined formulation of Angelica daurica, Coptidis rhizoma. and Glycyrrhiza glabra is expected to provide effective acne treatment.