• Restorative Dentistry and Endodontics
• /
• v.17 no.1
• /
• pp.166-180
• /
• 1992

One disadvantage of Glass Ionomer Cement Restoration is the difficulty in polishing. To find the appropriate polishing method, we polished the surface of Glass Ionomer Cement Restorations by 11 combination methods serially using disks shared with large-small particles and evaluated the polishing process in terms of surface roughness, surface roughness curve, and SEM findings. In addition, a visible light curing type bonding material was applied to evaluate the possible improvement in surface properties. The following results were obtained. 1. The disk surface of Glass Ionomer Cement was polished serially by disks with superfine particles, but it didn't become smooth. 2. The surface of Microfilled Composite resin became smoother as using a disk with finer particles. 3. When a visible light curing type bonding material was applied in finishing process, the surface of Glass Ionomer Cement became smooth as much as the applied matrix.

• Proceedings of the KIEE Conference
• /
• 2003.11c
• /
• pp.727-730
• /
• 2003

Electric pulp test is a method to examine the vitality of dental pulp using the electrical stimulation. During the pulp test, the current stimulates intradental nerve, and makes patients painful. Some studies were accomplished to measure the responses of subjects by stimulating over the sensory threshold. In this study, we examined the time delay between pain feeling and stimulation stop in clinical situation. And we measured the activated responses(EMG in anterior belly of digastric muscle, voice, and finger span). As a result, it was verified that the minimum and maximum delay was EMG and voice, respectively. By reducing the excessive stimulus time, the unnecessary pain can be minimized using EMG that has the minimum delay.

• Proceedings of the KIEE Conference
• /
• 2003.11c
• /
• pp.720-723
• /
• 2003

Electric stimulation of teeth is used for assessing pulp vitality. Because of very high and wide range of impedance of the enamel, electric pulp testers use high voltage, high output impedance and alternative current source. Most pulp testers use voltage stimulation method and their stimulating threshold levels significantly depend on each individual. Therefore, a constant current stimulator is necessary to minimize the effect of wide variation in enamel thickness. In this study, we constructed a constant current source type of pulp tester with the maximum current of 150 uA.

• Proceedings of the Korean Society of Rheology Conference
• /
• 2006.06a
• /
• pp.61-64
• /
• 2006

Soft materials, such as polymer solutions, gels and filamentous protein materials in cells, show complicated behavior due to their complex structures and dynamics with multiple characteristic time and length scales. Several complementary techniques have been developed to measure viscoelastic of soft materials. Especially, particle tracking microrheology, using the Brownian motion of particles in a medium to get rheological properties, has recently been improved both theoretically and experimentally. Compared to other conventional methods, video particle tracking microrheology has some advantages such as small sample volume, detecting spatial variation of local rheological properties, and less damage to sample materials. With these advantages, microrheology is more suitable to measure the properties of complex materials than other mechanical rheometries.

• Proceedings of the Korean Society of Rheology Conference
• /
• 2006.06a
• /
• pp.85-88
• /
• 2006

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04b
• /
• pp.457-459
• /
• 2004

정보화 시대로의 진입과 더불어 정보기술이 발달하고 있으며 소프트웨어는 정보시스템의 핵심요소가 되고 있다 이에 따라 소프트웨어의 품질에 대한 관심이 증가하고 소프트웨어에 대한 품질보증활동이 요구되고 있다. 국제표준화 기구에서는 ISO/IEC 9126과 ISO/IEC 14598을 국제 표준으로 제시하였으나 소프트웨어 개발과정에 대한 구체적인 적용 방안이 제시되지 못하고 정성적인 평가에 종점을 두고 있으며 정략적인 품질 평가를 위한 세부기준이 미흡한 실정이다. 본 논문에서는 소프트웨어 개발과정에서 정략적 품질평가를 위한 프레임워크를 연구하고자 한다 이를 위하여 개발단계에서 이례 당사자에 따른 소프트웨어 품질특성의 중요도를 분석하고 이들 특성의 가중치를 이용하여 정량적 소프트웨어 평가 프레임워크를 제시하며 프레임워크를 이용한 품질관리 방안을 제시함으로써 소프트웨어 개발과정에서 효과적으로 소프트웨어 품질을 관리할 수 있게 한다.

• Restorative Dentistry and Endodontics
• /
• v.5 no.1
• /
• pp.7-12
• /
• 1979

After applying three types of composite resins - Hi-Pol composite with Enamel bond, Hi-Pol composite without Enamel bond, Restodent - to the intact and the ground surface of tooth that had been acid etched for one or two minutes, the author observed the penetration of these resins into the acid etched enamel surface with scanning electron microscope. The results were as follows. 1. All the experimented materials showed the penetration into the acid etched enamel surface, and the average depth of penetration was 7 microns. 2. There was no significant difference in the penetration of these three resins despite different etching, time. 3. The grinding of the Enamel surface before acid - etching was not effective in altering the depth of penetration of these materials.

• Restorative Dentistry and Endodontics
• /
• v.12 no.2
• /
• pp.83-90
• /
• 1987

Composite resins has been widely used in dental clinics because of esthetic restoration. The aim of this study was to assess the effects of the cavity designs on the compressive stress of resin restoration. So, the author made the standardized specimen of four types (Type of speciemen are width 1.5mm, depth 2mm, width 1.5mm, depth 3mm, width 2mm, depth 2mm, width 2mm, depth 3mm). The compressive strength was measured by universal testing machine (Tong Kwang Co.) The results indicating following; 1. There was a statistic significance of compressive strength between four cavity forms. 2. There was no difference of significance of compressive strength between two resins. 3. There was a significance of compressive strength between depth 3mm width 1.5mm and depth 3mm width 2mm.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2004.05a
• /
• pp.1295-1298
• /
• 2004

국내 정보화 서비스 수준의 향상과 멀티미디어 유형의 자료의 증가로 초고속 광 네트워크 기술에 대한 관심이 높아지고 있다. 한편, 국방정보통신망은 ATM 기술을 기반으로 한 백본 망을 구성하여 운영 중이나 최근에는 매년 평균 1.5배 규모로 통화량이 증가하고 있는 추세이다. 이에 따라 수년 내에 현 백본 망에서 수용할 수 있는 통화량의 한계점에 도달할 것으로 예측되어 백본구조의 개선이 필요한 시점이다. 따라서 본 논문에서는 초고속 광 네트워크 기술을 이용하여 국방정보통신망의 백본구조를 개선하는 방안을 제시하고자 한다. 이를 위하여 최신 광 전송 및 네트워크 기술을 살펴보고, 실행 가능한 2가지 대안을 제시한다. 이어서 이들 대안들에 대한 장점, 제한사항 그리고 정량적인 비용분석을 통하여 최적안을 제안한다. 그 결과 국방정보통신망의 5년간 증설 및 운용유지 비용에서 28% 정도를 절감하면서 통화량 수용능력을 최소 1.7배 이상 확대하여 차후 망의 증설에 대비한 유연성을 확보하는 효과가 기대된다.

• Journal of the Korean Society for Precision Engineering
• /
• v.12 no.10
• /
• pp.121-129
• /
• 1995

The objective of this research is to develop an effective inspection planning strategy for sculptured surfaces by using 3-dimensional Coordinate Measuring Machine (CMM). First, the CAD/CAM database is generated by using the Bezier surface patch mathod and variable cutter step size approach for design and machining of the workpiece model. Then, optimum measuring point locations are determained based on the mean curvature analysis to obtain more effective inspection results for the given sample numbers. An optimal probe sequence generation method is proposed by implementing the Traveling Salesperson (TSP) algorithm and new guide point selection methods are suggested based on the concepts of the variable distance between the first and second guide points. Finally, simulation study and experimental work show the effectiveness of the proposed strategy.