• 감성과학
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• 제18권3호
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• pp.93-106
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• 2015

최근 고기능성 제품에 대한 수요가 증가함에 따라 ICT 기능과의 융합을 통한 스마트 의류는 일상생활 분야로 확대되고 있다. 그 중 하나로, 발열 텍스타일 및 제어 모듈을 통해 의복 내 발열기능을 조절하는 스마트 의류에 대한 관심이 높아지고 있으며, 발열 기능을 갖는 스마트 의류의 시장 전망이 높아지고 있으나, 발열 패드 부착위치에 따른 발열 기능의 효용성 및 온열감에 대한 연구는 부족한 실정이다. 본 연구에서는 발열 패드의 위치에 따른 피부온의 변화와 온열감에 대한 실증적 연구를 통하여 발열기능의 스마트 의류 개발을 위한 최적의 발열 위치를 도출하고자 하였다. 이를 위하여 20대 표준체형의 남성 10명을 피험자로 선정하였으며, 영하 $5^{\circ}C$의 인공기후실에서 20분의 안정기, 20분의 처치기, 40분의 회복기를 통해 11군데에서의 피부온, 직장온과 주관적 온열감을 측정, 평가하였다. 최종적으로, 발열패드를 위한 최적의 위치를 도출하고 제시하였다.

• 한국지반공학회논문집
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• 제36권2호
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• pp.29-42
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• 2020

본 연구에서는 모래지반에 설치된 해상풍력 지지용 직경 7m 모노파일의 p-y 곡선에 대한 수평하중-모멘트 조합의 영향을 분석하기 위하여 원심모형실험을 수행하였다. 이를 위하여 원심모형실험시스템을 구축하였고, 다수의 게이지를 부착한 계측용 모노파일 모형을 사용하여 68.83g에서 원심모형실험을 수행하였다. 지표면으로부터 직경의 1배와 직경의 5배 높이에서 하중재하를 하는 2개의 수평하중-모멘트 조합으로 재하시험이 수행되었다. 모형지반은 중간밀도의 모래로 조성되었다. 원심모형실험결과로부터 실험 p-y 곡선을 산정하였고 기존 문헌의 p-y 곡선과 비교하였다. 결과적으로 p-y 곡선에 대한 모멘트 조합의 영향이 미미함을 확인하였다. 또한, 근입깊이가 모노파일의 p-y 곡선에 영향을 미치는 것을 확인하였다

• The Journal of Advanced Prosthodontics
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• 제7권4호
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• pp.303-311
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• 2015

PURPOSE. The aim of this study was to compare the changes in retentive force of stud attachments for implant overdentures by in vitro 2-year-wear simulation. MATERIALS AND METHODS. Three commercially available attachment systems were investigated: Kerator blue, O-ring red, and EZ lock. Two implant fixtures were embedded in parallel in each custom base mounting. Five pairs of each attachment system were tested. A universal testing machine was used to measure the retentive force during 2500 insertion and removal cycles. Surface changes on the components were evaluated by scanning electron microscopy (SEM). A Kruskal-Wallis test, followed by Pairwise comparison, was used to compare the retentive force between the groups, and to determine groups that were significantly different (${\alpha}$<.05). RESULTS. A comparison of the initial retentive force revealed the highest value for Kerator, followed by the O-ring and EZ lock attachments. However, no significant difference was detected between Kerator and O-ring (P>.05). After 2500 insertion and removal cycles, the highest retention loss was recorded for O-ring, and no significant difference between Kerator and EZ lock (P>.05). Also, Kerator showed the highest retentive force, followed by EZ lock and O-ring, after 2500 cycles (P<.05). Based on SEM analysis, the polymeric components in O-ring and Kerator were observed to exhibit surface wear and deformation. CONCLUSION. After 2500 insertion and removal cycles, all attachments exhibited significant loss in retention. Mechanism of retention loss can only be partially explained by surface changes.

• Structural Engineering and Mechanics
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• 제65권2호
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• pp.129-139
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• 2018

Post-tensioning (PT) tendons are commonly used for the assembly of modularized concrete members, and tension is applied to the tendons during construction to facilitate the integrated behavior of the members. However, the tension in a PT tendon decreases over time due to steel corrosion and concrete creep, and consequently, the stress on the anchor head that secures the PT tendon also diminishes. This study proposes an automatic detection system to identify tension reduction in a PT tendon using pulsed-eddy-current (PEC) measurement. An eddy-current sensor is installed on the surface of the steel anchor head. The sensor creates a pulsed excitation to the driving coil and measures the resulting PEC response using the pick-up coil. The basic premise is that the tension reduction of a PT tendon results in stress reduction on the anchor head surface and a change in the PEC intensity measured by the pick-up coil. Thus, PEC measurement is used to detect the reduction of the anchor head stress and consequently the reduction of the PT tendon force below a certain threshold value. The advantages of the proposed PEC-based tension-reduction-detection (PTRD) system are (1) a low-cost (< $ 30), low-power (< 2 Watts) sensor, (2) a short inspection time (< 10 seconds), (3) high reliability and (4) the potential for embedded sensing. A 3.3 m long full-scale monostrand PT tendon was used to evaluate the performance of the proposed PTRD system. The PT tendon was tensioned to 180 kN using a custom universal tensile machine, and the tension was decreased to 0 kN at 20 kN intervals. At each tension, the PEC responses were measured, and tension reduction was successfully detected.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.2879-2883
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• 2013

Objective: To investigate differences in mutations of epidermal growth factor receptor (EGFR) gene and relationships with clinicopathological features in patients with non-small cell lung cancer (NSCLC) between Uygur and Han ethnic groups. Methods: The Scorpions amplification refractory mutation system (Scorpions ARMS) was used to measure mutations in exons 18, 19, 20 and 21 of the EGFR gene in paraffin-embedded tumor tissue from NSCLC cases, and statistical analysis was performed to investigate links with clinicopathological features in different histological types of NSCLC. Results: Results from ARMS testing showed EGFR mutations in tumor tissues from six (6) of 50 NSCLC patients of Uygur ethnic group, with a positive rate of 12.0%; four of them (4) had exon 19 deletion in EGFR, and two (2) had L858R point mutation in exon 21 of EGFR. Statistically significant difference was noted in EGFR genetic mutation between adenocarcinoma and non-adenocarcinoma (P < 0.05), but no differences with gender, age group, smoking status, or stage (P > 0.05). EGFR mutations were detected in tumor tissues from 27 of 49 NSCLC patients of Han ethnic group, with a positive rate of 55.1%; 19 of them had exon 19 deletions, seven (7) had L858R point mutations in exon 21 of EGFR and one (1) had mutations in both exon 18 G719X and exon 20 T790M of EGFR. Statistically significant differences were noted in EGFR genetic mutations between genders and between adenocarcinoma and non-adenocarcinoma (P<0.05), but not with age group, smoking status, or stage (P > 0.05). Conclusion: Statistically significant differences were noted in the positive rates of EGFR genetic mutations in NSCLC patients between Uygur and Han ethnic groups, with lower positive rates for the Uygur cases.

• 한국정보통신학회논문지
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• 제19권8호
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• pp.1965-1972
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• 2015

비행시험 발사통제 시스템은 유도무기 비행시험 시 사격통제 시스템과 연동하여 동작하고, 유도무기의 종류 및 시험 목적에 따라 시험의 통제 및 상황 감시를 하는 시스템이다. 사격통제 시스템과 비행시험 발사통제 시스템이 연동하기 위한 메시지 구조, 통신 프로토콜, 데이터 타입 등은 발사통제 ICD(Interface Control Document)에 정의되어 있고, ICD는 유도무기 체계별, 시험 목적별로 모두 다르게 구성되어 있다. 기존에는 사격통제 시스템과 연동하기 위해 별도의 연동 소프트웨어를 개발하였으나, 이는 다양한 문제점을 가지고 있었다. 따라서 다양한 발사통제 ICD를 수용할 수 있도록 새로운 파싱 알고리즘을 개발하였고, 사격통제 시스템과 연동하여 다양한 메시지들이 송ㆍ수신되는 것을 확인하여 알고리즘이 정상적으로 동작하는 것을 검증하였다.

• 한국재난관리표준학회지
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• 제3권1호
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• pp.25-32
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• 2010

콘크리트 구조물 내의 철근탐사는 구조물의 상태를 평가하는 중요한 단계중의 하나이다. 본 연구에서는 비파괴 철근탐사기 중 전자기유도법과 전자파레이터법의 측정 정밀도 제고를 위한 제반 실험을 수행하였다. 시험에 크기가 1,000 mm(길이)${\times}300mm$(폭)이고 철근직경, 피복두께가 각기 다른 4개의 콘크리트 시험체를 이용하였다. 실험은 90일간의 공기중 건조 후와 3, 24, 48시간 및 28일간의 침수 후 실시되었다. 실험결과, 전자기유도법의 경우, 철근직경이 커짐에 따라 오차가 증가하는 것으로 나타났으며, 전자파레이더법의 경우에는 실제 피복두께에 맞는 비유전율에 따라 측정하여 깊은 심도의 경우에도 신뢰도가 우수한 것으로 나타났다. 수분함량이 3.6~5.5%로 증가함에 따라서 콘크리트 시험체의 비유전율도 증가하는 경향을 보이는 것으로 나타났다. 따라서 수분함량이 비유저율을 결정하는데 주요한 영향인자 중의 하나라는 것을 확인할 수 있었으며, 수분함유량에 따른 유전상수 산출식을 도출, 제시하였다.

• The Journal of Advanced Prosthodontics
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• 제8권4호
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• pp.285-289
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• 2016

PURPOSE. This study evaluated the effect of chemical surface treatment using methyl formate-methyl acetate (MF-MA) solution on the tensile bond strength between acrylic denture teeth and auto-polymerized acrylic resin. MATERIALS AND METHODS. Seventy maxillary central incisor acrylic denture teeth for each of three different brands (Yamahachi New Ace; Major Dent; Cosmo HXL) were embedded with incisal edge downwards in auto-polymerized resin in polyethylene pipes and ground with silicone carbide paper on their ridge lap surfaces. The teeth of each brand were divided into seven groups (n=10): no surface treatment (control group), MF-MA solution at a ratio of 25:75 (v/v) for 15 seconds, 30 seconds, 60 seconds, 120 seconds, 180 seconds, and MMA for 180 seconds. Auto-polymerized acrylic resin (Unifast Trad) was applied to the ground surface and polymerized in a pressure cooker. A tensile strength test was performed with a universal testing machine. Statistical analysis of the results was performed using two-way analysis of variance (ANOVA) and post-hoc Dunnett T3 test (${\alpha}$=.05). RESULTS. The surface treatment groups had significantly higher mean tensile bond strengths compared with the control group (P<.05) when compared within the same brand. Among the surface treatment groups of each brand, there were no significantly different tensile bond strengths between the MF-MA groups and the MMA 180 second group (P>.05), except for the Yamahachi New Ace MF-MA 180-second group (P<.05). CONCLUSION. 15-second MF-MA solution can be an alternative chemical surface treatment for repairing a denture base and rebonding acrylic denture teeth with auto-polymerized acrylic resin, for both conventional and cross-linked teeth.

• 구강회복응용과학지
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• 제22권3호
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• pp.211-220
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• 2006

Need of porcelain-repair system is largely demanding as dental porcelain restorations are increased in clinical dentistry. This study investigated shear bond strength of commercial porcelain-repair systems on dental porcelain and their reliability. Experimental groups were as follows; Group A Super Bond C&B, Group B Porcelain repair kit, Group C Ceramic repair, and Group D Spectrum system as a control. Porcelain disks were fired and embedded in epoxy resin. Porcelain surface were ground using 220 grit SiC disk, then cleaned in ultrasonic bath. Then porcelain specimens were treated with each repair system. A clear polystyrene cylinder 3.5 mm in internal diameter was filled with composite resin. Then the resin cylinder was polymerized with a visible light curing unit. Thirty one specimens at each group were prepared and stored at $37^{\circ}C$ distilled water for 48 h. Specimens were tested in an Instron testing machine according to ISO TR 11405. Mean shear bond strength and standard deviation of each group was $15.7{\pm}4.1MPa$ (Group A), $12.8{\pm}4.9MPa$ (Group B), $7.2{\pm}3.0MPa$ (Group C) and $9.6{\pm}2.2MPa$ (Group D). ANOVA and Tukey HSD post-hoc test showed that there were significant differences between groups (p<0.05). Data of bond strength were analyzed with two-parameter Weibull distribution. Confidence interval of Weibull modulus (m-parameter) at 95% of Group A (3.5-6.3) and Group D (3.6-6.0) were significantly higher than Group B (2.2-3.7) and Group C (2.0-3.4). There was little correlation between mean shear bond strength and Weibull modulus. Results indicated that acid-etching of porcelain surface increased porcelain-resin shear bonding strength.

• 대한치과교정학회지
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• 제45권6호
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• pp.299-307
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• 2015

Objective: The aims of this study were to compare the shear bond strength between orthodontic metal brackets and glazed zirconia using different types of primer before applying resin cement and to determine which primer was more effective. Methods: Zirconia blocks were milled and embedded in acrylic resin and randomly assigned to one of four groups: nonglazed zirconia with sandblasting and zirconia primer (NZ); glazed zirconia with sandblasting, etching, and zirconia primer (GZ); glazed zirconia with sandblasting, etching, and porcelain primer (GP); and glazed zirconia with sandblasting, etching, zirconia primer, and porcelain primer (GZP). A stainless steel metal bracket was bonded to each target surface with resin cement, and all specimens underwent thermal cycling. The shear bond strength of the specimens was measured by a universal testing machine. A scanning electron microscope, three-dimensional optical surface-profiler, and stereoscopic microscope were used to image the zirconia surfaces. The data were analyzed with one-way analyses of variance and the Fisher exact test. Results: Group GZ showed significantly lower shear bond strength than did the other groups. No statistically significant differences were found among groups NZ, GP, and GZP. All specimens in group GZ showed adhesive failure between the zirconia and resin cement. In groups NZ and GP, bonding failed at the interface between the resin cement and bracket base or showed complex adhesive and cohesive failure. Conclusions: Porcelain primer is the more appropriate choice for bonding a metal bracket to the surface of a full-contour glazed zirconia crown with resin cement.