• 한국통신학회논문지
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• 제35권11B호
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• pp.1624-1630
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• 2010

본 논문은 도시통합관제플랫폼에서 발생되는 다양한 복합이벤트에 대해, 해당 복합이벤트에 의해 발생되는 업무프로세스 및 Action을 도시통합관제플랫폼과 다수의 u-서비스시스템 간 분담 또는 협업하여 처리할 수 있도록 복합 이벤트에 대한 업무 프로세스 및 Action을 검색, 변환, 배포하는 시스템 및 방법을 제시하였다. 제시된 방법을 적용하면 복합이벤트 발생시 신속하고 유기적인 대응을 통해 피해 비용 및 피해 범위의 확산을 방지하는 효과가 있다. 또한 복합이벤트의 프로세스 및 Action이 추가 삭제, 보완 등과 같이 수시로 변경되는 경우에도, 도시통합관제플랫폼에서만 업무 프로세스 및 Action을 수정하여 각 u-서비스시스템에 배포하면 분담 및 협업 처리를 할 수 있게 되므로 일의 복잡도를 단순화 시키고 유연한 대응을 할 수 있을 것으로 기대된다.

• Restorative Dentistry and Endodontics
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• 제40권3호
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• pp.188-194
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• 2015

Objectives: This study evaluated the effect of lactic acid and acetic acid on the microhardness of a silorane-based composite compared to two methacrylate-based composite resins. Materials and Methods: Thirty disc-shaped specimens each were fabricated of Filtek P90, Filtek Z250 and Filtek Z350XT. After measuring of Vickers microhardness, they were randomly divided into 3 subgroups (n = 10) and immersed in lactic acid, acetic acid or distilled water. Microhardness was measured after 48 hr and 7 day of immersion. Data were analyzed using repeated measures ANOVA (p < 0.05). The surfaces of two additional specimens were evaluated using a scanning electron microscope (SEM) before and after immersion. Results: All groups showed a reduction in microhardness after 7 day of immersion (p < 0.001). At baseline and 7 day, the microhardness of Z250 was the greatest, followed by Z350 and P90 (p < 0.001). At 48 hr, the microhardness values of Z250 and Z350 were greater than P90 (p < 0.001 for both), but those of Z250 and Z350 were not significantly different (p = 0.095). Also, the effect of storage media on microhardness was not significant at baseline, but significant at 48 hr and after 7 day (p = 0.001 and p < 0.001, respectively). Lactic acid had the greatest effect. Conclusions: The microhardness of composites decreased after 7 day of immersion. The microhardness of P90 was lower than that of other composites. Lactic acid caused a greater reduction in microhardness compared to other solutions.

• Earthquakes and Structures
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• 제17권2호
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• pp.233-244
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• 2019

In this work, we have studied the effects of different soil thicknesses, haunch heights, reinforcement forms and construction technologies on the seismic performance of a composite precast fabricated utility tunnel by pseudo-static tests. Five concrete specimens were designed and fabricated for low-cycle reciprocating load tests. The hysteretic behavior of composite precast fabricated utility tunnel under simulated seismic waves and the strain law of steel bars were analyzed. Test results showed that composite precast fabricated utility tunnel met the requirements of current codes and had good anti-seismic performance. The use of a closed integral arrangement of steel bars inside utility tunnel structure as well as diagonal reinforcement bars at its haunches improved the integrity of the whole structure and increased the bearing capacity of the structure by about 1.5%. Increasing the thickness of covering soil within a certain range was beneficial to the earthquake resistance of the structure, and the energy consumption was increased by 10%. Increasing haunch height within a certain range increased the bearing capacity of the structure by up to about 19% and energy consumption by up to 30%. The specimen with the lowest haunch height showed strong structural deformation with ductility coefficient of 4.93. It was found that the interfaces of haunches, post-casting self-compacting concrete, and prefabricated parts were the weak points of utility tunnel structures. Combining the failure phenomena of test structures with their related codes, we proposed improvement measures for construction technology, which could provide a reference for the construction and design of practical projects.

• 한국컴퓨터정보학회논문지
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• 제14권10호
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• pp.189-197
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• 2009

웹 서비스 기술이 안정화됨에 따라 기업내 혹은 기업간 웹 서비스들을 통합한 합성된 웹 서비스의 연구가 활발히 진행되고 있다. 또한, 비기능적 속성은 다르지만 유사한 기능을제공하는 웹 서비스들의 증가로 인하여 품질관리는 중요한 이슈로 여겨지고 있다. 품질관리를 위해서는 모니터링 기능이 필요하다. 본 논문에서는 중개자를 통한 합성된 웹 서비스의 품질 모니터링 시스템의 설계를 제안한다. 이 시스템은 OWL-S를 사용하여 합성된 서비스의 프로세스를 명세하며 WS-Policy를 사용하여 다양한 요구사항인 정책(각 서비스 입력 출력값, 품질요소 및 품질요소 값 등)을 명세하여 합성된 서비스 프로세스모델에 첨부한다. 또한, 센서를 이용하여 명세한 정책과실제로 모니터링된 데이터의 값을 비교하여 불일치하면 위반사항이 발생하였음을 웹 서비스 제공자 및 사용자에게 통보함으로서 품질을 관리한다. 제안한 시스템의 검증을 위하여 여행 예약 시스템 예제를 가지고 평균 응답시간과 타임아웃 정책을 적용하여 모니터링한 결과를 보여 준다.

• Restorative Dentistry and Endodontics
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• 제46권2호
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• pp.23.1-23.11
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• 2021

Objectives: This study assessed the reliability of digital color measurements using images of resin composite specimens captured with a cellphone. Materials and Methods: The reference color of cylindrical specimens built-up with the use of resin composite (shades A1, A2, A3, and A4) was measured with a portable spectrophotometer (CIELab). Images of the specimens were obtained individually or pairwise (compared shades in the same photograph) under standardized parameters. The color of the specimens was measured in the images using RGB system and converted to CIELab system using image processing software. Whiteness index (WI_D) and color differences (ΔE₀₀) were calculated for each color measurement method. For the cellphone, the ΔE₀₀ was calculated between the pairs of shades in separate images and in the same image. Data were analyzed using 2-way repeated-measures analysis of variance (α = 0.05). Linear regression models were used to predict the reference ΔE₀₀ values of those calculated using color measured in the images. Results: Images captured with the cellphone resulted in different WI_D values from the spectrophotometer only for shades A3 and A4. No difference to the reference ΔE₀₀ was observed when individual images were used. In general, a similar ranking of ΔE₀₀ among resin composite shades was observed for all methods. Stronger correlation coefficients with the reference ΔE₀₀ were observed using individual than pairwise images. Conclusions: This study showed that the use of cellphone images to measure the color difference seems to be a feasible alternative providing outcomes similar to those obtained with the spectrophotometer.

• Steel and Composite Structures
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• 제5권2_3호
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• pp.169-180
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• 2005

Current codes of practice do not exist in isolation, and rules that have been developed assume certain material properties and minimum workmanship in fabrication and erection. These are either in separate documents or different parts of the code. This paper explains the main requirements for materials and workmanship and how they can be related to design and construction in general. The use of very high strength steels is also considered and the measures that may be needed to allow their use with modern codes are also presented.

• 한국항해항만학회지
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• 제32권8호
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• pp.577-582
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• 2008

이 논문은 부산항 방파제 진입항로에서 강한 횡조류가 있는 경우 60,000 DWT의 파나막스 선박의 조종에 있어 선속에 따른 영향을 파악하기 위하여 3년 이상의 선장 경력을 가진 76명의 조종자가 선박조종 시뮬레이션을 실시하고 그 결과를 선박의 근접도 계측, 제어도 계측, 조선자의 주관적 계측을 통하여 분석하기로 한다. 조류는 남서 방향, 2노트이고 독립 변수인 선속은 각각 5노트, 10노트로 한다. 시뮬레이션의 분석 결과는 다음과 같다. ${(1)}$ 부산항 방파제 진입항로에서 선속 5노트인 경우 드리프트 앵글을 $10^{\circ}$ 이상으로 하는 것은 선수가 방파제 입구를 벗어나게 되므로 조종자는 심리적으로 이 각도 이상은 취하지 않는 경향이 있다. ${(2)}$ 선속 5노트에서의 경우가 선속 10노트보다 주관적 계측치, 선박의 근접도, 제어도가 상대적으로 크게 나타나고 있다. ${(3)}$ 선박의 제어도 계측 항목을 무차원화하여 이를 단일 지표로 표시하는 방법을 제안하였다.

• The Journal of Advanced Prosthodontics
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• 제7권5호
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• pp.368-374
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• 2015

PURPOSE. The aim of the study was to evaluate the effect of abutment shade, ceramic thickness, and coping type on the final shade of zirconia all-ceramic restorations. MATERIALS AND METHODS. Three different types of disk-shaped zirconia coping specimens (Lava, Cercon, Zirkonzahn: ${\phi}10mm{\times}0.4mm$) were fabricated and veneered with IPS e.max Press Ceram (shade A2), for total thicknesses of 1 and 1.5 mm. A total of sixty zirconia restoration specimens were divided into six groups based on their coping types and thicknesses. The abutment specimens (${\phi}10mm{\times}7mm$) were prepared with gold alloy, base metal (nickel-chromium) alloy, and four different shades (A1, A2, A3, A4) of composite resins. The average $L^*$, $a^*$, $b^*$ values of the zirconia specimens on the six abutment specimens were measured with a dental colorimeter, and the statistical significance in the effects of three variables was analyzed by using repeated measures analysis of variance (${\alpha}$=.05).The average shade difference (${\Delta}E$) values of the zirconia specimens between the A2 composite resin abutment and other abutments were also evaluated. RESULTS. The effects of zirconia specimen thickness (P<.001), abutment shade (P<.001), and type of zirconia copings (P<.003) on the final shade of the zirconia restorations were significant. The average ${\Delta}E$ value of Lava specimens (1 mm) between the A2 composite resin and gold alloy abutments was higher (close to the acceptability threshold of 5.5 ${\Delta}E$) than th ose between the A2 composite resin and other abutments. CONCLUSION. This in-vitro study demonstrated that abutment shade, ceramic thickness, and coping type affected the resulting shade of zirconia restorations.

• Imaging Science in Dentistry
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• 제42권2호
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• pp.89-93
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• 2012

Purpose : Clinicians commonly encounter cases in which it is difficult to determine whether adjacent radiopacities are normal or pathologic. The ideal radiopacity of composite resin is equal to or higher than that of the same thickness of aluminum. We aimed to investigate the possible effects of different curing times on the post-24-hour radiopacity of composite resins on digital radiographs. Materials and Methods : One mm thick samples of Filtek P60 and Clearfil resin composites were prepared and cured with three regimens of continuous 400 mW/$cm^2$ irradiance for 10, 20 and 30 seconds. Along with a 12-step aluminum step wedge, digital radiographs were captured and the radiopacities were transformed to the equivalent aluminum thicknesses. Data were compared by a general linear model and repeated-measures of ANOVA. Results : Overall, the calculated equivalent aluminum thicknesses of composite resins were increased significantly by doubling and tripling the curing times (F(2,8)=8.94, p=0.002). Notably, Bonferroni post-hoc tests confirmed that the radiopacity of the cured Filtek P60 was significantly higher at 30 seconds compared with 10 seconds (p=0.04). Although the higher radiopacity was observed by increasing the time, other comparisons showed no statistical significance (p>0.05). Conclusion : These results supported the hypothesis that the radiopacity of resin composites might be related to the duration of light curing. In addition to the current standards for radiopacity of digital images, defining a standard protocol for curing of dental materials should be considered, and it is suggested that they should be added to the current requirements for dental material.

• Structural Engineering and Mechanics
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• 제87권4호
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• pp.297-304
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• 2023

Targeted introduction of explosion-resisting and energy-absorbing materials and optimization of explosion-resisting composite structural styles in underground engineering are the most important measures for modern engineering protection. They could also improve the survivability of underground engineering in wartime. In order to test explosion-resisting and energy-absorbing effects of high-performance equal-sized-aggregate (HPESA) concrete, the explosive loading tests were conducted on HPESA concrete composite plates by field simple explosion craters. Time-history curves of the explosion pressure at the interfaces were obtained under six conditions with different explosion ranges and different thicknesses of the HPESA concrete plate. Test results show that under the same explosion range, composite plate structures with different thicknesses of the HPESA concrete plate differ significantly in terms of the wave-absorbing ability. Under the three thicknesses in the tests, the wave-absorbing ability is enhanced with the growing thickness and the maximum pressure attenuation index reaches 83.4%. The energy attenuation coefficient of the HPESA concrete plate under different conditions was regressively fitted. The natural logarithm relations between the interlayer plate thickness and the energy attenuation coefficient under the two explosion ranges were attained.