• 마이크로전자및패키징학회지
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• 제21권4호
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• pp.117-123
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• 2014

써멀비아나 수직 배선으로 사용하기 위한 Cu 관통비아를 열린 비아 hole의 top-down filling 도금공정과 bottom-up filling 도금공정으로 형성 후 미세구조를 관찰하였다. 직류도금전류를 인가하면서 열린 비아 홀 내를 top-down filling 도금하거나 bottom-up filling 도금함으로써 내부기공이 없는 건전한 Cu 관통비아를 형성하는 것이 가능하였다. 열린 비아 홀의 top-down filling 공정에서는 Cu filling 도금 후 시편의 윗면과 밑면에서 과도금된 Cu 층을 제거하기 위한 chemical-mechanical polishing(CMP) 공정이 요구되는데 비해, 열린 비아 홀의 bottom-up filling 공정에서는 과도금된 Cu층을 제거하기 위한 CMP 공정이 시편 윗면에서만 요구되는 장점이 있었다.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4317-4328
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• 2023

To ensure the measuring accuracy of the wall temperature, the outer wall temperature measurement values by using three kinds of thermocouple welding methods were analyzed and evaluated in the paper, including single-point flush-mounted in the wall groove method, single-point insert-mounted in the wall groove, and outer surface direct welding method, based on the application of a tube-in-tube condensing heat exchanger. And the impacts of silver, tin, and thermal resistance adhesive as filling materials on wall temperature measurement were also investigated, and the results were compared to that obtained without filling materials. The results showed that the wall temperatures measured by the three welding methods were lower than the theoretically calculated value. And the wall temperature measured by the outer surface direct welding method was lowest under the same experimental conditions. The wall temperatures measured by single-point flush-mounted and insert-mounted in the wall groove methods were also affected by different welding filling materials. It was found that the greater the thermal resistance of filling materials, the smaller the heat loss. By analyzing the reasons for the low measured value of wall temperature, a new wall temperature measurement method was developed to improve the accuracy of the current measurement method. Meanwhile, the outer wall temperature measurement experiments of vertical and horizontal heat transfer tubes were carried out to validate and calibrate the improved outer wall temperature measurement method. The results showed that the average outer wall temperature deviation measured by the improved wall temperature measurement method ranged from - 0.82% to +2.29% for vertical tubes and - 4.75% to - 1.44% for horizontal tubes, and the improved measurement method had good measurement accuracy.

• 디지털융복합연구
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• 제12권1호
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• pp.415-421
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• 2014

본 논문에서는 무작위 공간 채움 곡선을 스캐닝 경로로 사용하는 디지털 하프토닝 방법에 대한 문제점과 개선 방안에 관해 제시한다. 무작위 공간 채움 곡선은 공간 채움 곡선의 자기 유사성으로 인한 단점을 해소하기 위한 방법으로 제안되었다. 스캐닝 경로에 무작위성을 도입하여 일정한 밝기를 가진 영역에서 발생할 수 있는 규칙적인 패턴을 줄이기 위해 사용되었다. 그러나 무작위 공간 채움 곡선을 사용한 하프토닝에도 일부 영역에서 경로를 따라 밝기가 지나치게 밝아지는 결과를 보일 수 있는 문제점이 발생한다. 본 논문에서는 이러한 문제점의 원인을 제시하고 이를 해결할 수 있는 방법으로써 단일 화소로 제한된 확산 방식을 제시한다. 이러한 방식은 효과적으로 오차의 과다 누적을 막아주며 하프토닝에도 개선된 결과를 보여준다.

• Earthquakes and Structures
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• 제24권3호
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• pp.205-215
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• 2023

Currently, many studies are underway at home and abroad on the seismic performance evaluation and dry construction method of the masonry structure. In this study, a dry stack masonry wall system without mortar using concrete blocks is proposed, and investigate the seismic performance of dry filling wall frames through experimental studies. First, two types of standard blocks and key blocks were designed to assemble dry walls of concrete blocks. And then, three types of experiments were manufactured, including pure frame, 1/2 height filling wall frame, and full height filling wall frame, and cyclic load experiments in horizontal direction were performed to analyze crack patterns, load displacement history, rebar deformation yield, effective stiffness change, displacement ductility, and energy dissipation capacity. According to the experimental results, the full height filling wall frame had the largest horizontal resistance against the earthquake load and showed a high energy dissipation capacity. However, the 1/2 height filling wall frame requires attention because the filling wall constrains the effective span of the column, limiting the horizontal displacement of the frame. In addition, the concrete block was firmly assembled in the vertical direction of the wall as the horizontal movement between the concrete blocks was allowed within installation margin, and there was no dropping of the assembled concrete block.

• 대한치과보철학회지
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• 제36권1호
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• pp.133-149
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• 1998

Clinical application of composite resin recently draw great concerns in dentistry. Especially due to advantages such as esthetics, adhesiveness, simple clinical procedures, various shapes and kinds of composite resins are widely being applied to prosthodontics, conservative dentistry, and orthodontics. But, clinical problems attributable to the polymerization shrinkage of composite resin have been proposed, and we have to regard clinical problems such as secondary caries, loss of restoration, fracture of the surrounding tooth structure, marginal discoloration, and tooth sensitivity, and many portions are remained to be overcome. Therefore, this study attempts to analyze stress distribution between resin and tooth structure which is generated during polymerization shrinkage of composite resin using three dimensional finite element method. Three dimensional finite element models with conventional box-shape cavity and erosion/abrasion type V-shape lesion cavity in upper central incisor were developed. These cavities were filled with four different types of placement techniques. (bulk filling, horizontal increment filling, oblique occlusal increment filling, oblique gingival increment filling) The stresses generated by polymerization shrinkage of composite resin were calculated. The results analyzed with three dimensional finite element method were as follows : 1. The increment filling technique showed the highest maximum normal stress in both conventional box-shape and V-shape cavities and showed a tendency to decrease after complete polymerization. 2. The bulk filling technique resulted in increased stresses during the curing process in both conventional box-shape and V-shape cavities and the highest maximum normal stress occurred after complete polymerization. 3. The bulk filling resulted in the lowest maximum normal stress in both box-shape and V-shape cavities 4. Regardless of placement method, in conventional box-shape cavity, the maximum normal stress increased in dentin floor, enamel, dentin sequence and in V-shape cavity, the maximum normal stress increased in enamel, dentin sequence.

• Restorative Dentistry and Endodontics
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• 제15권2호
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• pp.104-114
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• 1990

The purpose of this study was to evaluate the adaptation of root canal filling material to the dentinal wall of root canal and to compare the sealing ability of the root canal filling materials using ultrasonic endodontic instrument with injection-molded thermoplasticized gutta-percha filling method and lateral condensation method. Fifty fresh human single root exlracted for orthodontic treatment, were randomly selected, and instrumented by step-back technique. And then, the teeth were divided into 5 groups according to each root canal filling methods. In the experimental group 1 and group 2, the root canals were filled with gutta perdia cases using ultrasonic instrument with and without sealer. In the experimental group 3 and 4, using jection-moldeed thermoplasticized gutta-percha method by obtul$^{(R)}$ canals were filled with and without sealer. In the control group, the canals were filled with sealer by lateral candensation. And then, 5 teeth of each group were immersed in black Indian ink, decalcified and cleared. The depth of dye penetration into the root canal were evaluated with stereoscope (Reichert Ltd., USA). Among the 5 teeth remaining in each group, the single longituding grooves were made on the labial and lingual root surfaces and then immersed in the liquid nitrogen to fracture the teeth spontaneously without any distortions of gutta-percha. Each specimens were examined with X-650 Scanning Electron Microscope(Hitachi ltd, Japan) to show the adaptation to the canal wall, void, homogenicity of filling material and location of gutta-percha or sealer in the dentinal tubules of the root canal. The observations were as follows : 1. The experimental group 1 showed smaller mean dye penetration than control group, and showed the penetraton of sealer in the dentinal tubules of apical third of the root canal. 2. The experimental group 2 and group 4 showed the penetration of gutta-percha in the dentinal tubules of root canals. 3. The experimental group 1 and group 3 showed less mean dye penetration than the experimental group 2 and group 4. 4. The experimental group 1 and group 2 showed better adaptation of filling materials than control group.

• 한국콘텐츠학회논문지
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• 제15권2호
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• pp.21-30
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• 2015

Mixed raster content 모델 기반의 영상 부호화는 전경과 배경 레이어에 빈 영역인 don't care region (DCR)이 발생하게 되며, 이 영역에 대한 신호 채움 방식에 따라 전체적인 부호화 성능이 큰 영향을 받게 된다. DCR을 채우기 위한 대부분의 기존 기법들은 홀 주변 기존 영역의 특성을 효율적으로 이용하지 않아 신호 채움 후에도 기존 신호 영역에 존재하던 고주파 성분이 반영될 뿐 아니라, DCR 경계에서의 신호 불연속으로 인해 고주파 성분이 추가적으로 발생한다는 문제점을 갖고 있다. 이 문제를 해결하기 위해 본 논문은 우선순위 기반의 적응적 영역 확장법을 이용한 새로운 DCR 채움 알고리즘을 제안한다. 제안 알고리즘은 분수령 알고리즘을 이용하여 DCR의 각 홀 픽셀에 대한 신호 특성을 판단한 후, 이를 토대로 영역 채움의 우선순위를 결정한다. 이 우선 순위를 기반으로 영역 확장을 수행함으로써 고주파 성분을 포함하고 있는 영역의 확장이 최소화되어 전체적인 부호화 효율이 향상될 수 있다. 실험 결과를 통해 제안 알고리즘이 비교 대상 알고리즘에 비해 효율적인 신호 채움으로 우수한 부호화 성능을 가짐을 보인다.

• Restorative Dentistry and Endodontics
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• 제18권1호
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• pp.55-72
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• 1993

The aim of this study was to compare the marginal leakage of class II light curing composite resin restoration according to filling methods. With using acid etching technique and dentin bonding agent, various methods were suggested to eliminate or reduce the marginal leakage. In this study, class II cavities were prepared in 100 extracted human premolars with cementum margin(1mm below the CEJ) and the teeth were randomly assigned to 5 groups of 20 teeth each. The teeth in group 1, 2, 3 and 4 were restored by direct filling methods using P-50 and Clearfil Photoposterior of 10 teeth each, but the method of insertion of the restorative materials varied with each group. And the teeth in group 5 were restored by inlay method using Kulzer Inlay and CR Inlay. Filling methods are as follows : Group 1 : The composite resin was inserted in one layer in the proximal box and one layer in the occlusal portion. Group 2 : Insertion was in two equally thick horizontal layers in the proximal box. Group 3 : Insertion was in two diagonally placed layers in the proximal box. Group 4 : The composite resin was inserted in the same way as in group 3 except that a glass ionomer liner was first placed on the axial wall and gingival floor. Group 5 : The teeth were restored by Inlay technique using dure cure resin cement. All the teeth were thermocycled, stained with 1 % methylene blue solution, sectioned mesiodistally, and scored for marginal leakage. To compare the marginal leakage, ANOVA and T-test were used in analysis. The following results were obtained : 1. In direct filling methods, there was no significant difference in marginal leakage at both occlusal and cervical margins. 2. In all groups, occlusal margin showed significantly less leakage than cervical margin. 3. In group using glass ionomer liner, there was no significant reduction of marginal leakage at the cervical margin. 4. The group restored by inlay method showed significantly less marginal leakage than groups restored by direct filling methods at both occlusal and gingival margins. 5. There was no significant difference in each group according to filling materials.

• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.499-512
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• 1994

The purpose of this study was to evaluate the microleakage electrochemically using different retrograde filling materials, different root resection angle, and different cavity preparation instruments. 104 extracted single-rooted teeth were selected for this study. 100 teeth were used as experimental groups and four was used as controls. Anatomical crowns were resected, root canals were prepared, and the apical 2 mm of roots were removed. The experimental roots were randomly divided into five equal groups. Experimental groups : Group 1. no bevel, cavity preparation with ultrasonic instruments, amalgam filling Group 2. no bevel, cavity preparation with ultrasonic instruments, SuperEBA cement filling Group 3. no bevel, cavity preparation with ultrasonic instruments, desiccated ZOE filling Group 4. $45^{\circ}$ bevel, cavity preparation with ultrasonic instruments, amalgam filling Group 5. no bevel, cavity preparation with conventional bur, amalgam filling Microleakage was measured once a day for 30 days using electrochemical method and were analyzed statistically. The results were as follows : 1. The group with Super EBA cement filling showed the least marginal leakage from second to fourth day(p<0.05), there was no significant difference between the group with amalgam filling during eighth to eighteenth day(p>0.05), but after the nineteenth day here was a higher marginal leakage than the group with amalgam filling(p<0.05). 2. The group with desiccated ZOE filling demostrated that the highest marginal leakage, started on the eighth day(p<0.05). 3. The group using ultrasonic instrument showed lower marginal leakage than the group using bur until the nineteenth day(p<0.05), but there was no significant differnce with the group using bur after twentythird day(p>0.05). 4. The group without bevel showed lower marginal leakage than the group with bevel (p<0.05). 5. Whether bevel or nor had much more effect on marginal leakage than with cavity perparation instrument when the cavity was retrogrdefilled with amalgam(stepwise regression).

• 정보과학회 논문지
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• 제44권2호
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• pp.186-194
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• 2017

깊이 영상 기반 렌더링은 깊이 정보를 활용하여 가상 시점의 영상을 생성하는 기술로 다양한 3차원 영상시스템에서 필요로 하는 기술이다. 깊이 영상 기반 렌더링에서 가장 어려운 과제는 가상 시점 영상에서 새롭게 드러나는 부분을 채우는 과정이다. 영상 인페인팅은 이 과정에서 보편적으로 활용되는 방법이다. 본 논문에서는 홀을 채우는 과정에서 발생하는 오류를 줄이고 자연스럽게 채우는 방법을 제안한다. 먼저 색상 영상의 정보와 깊이 정보를 활용하여 지역적으로 적응적 패치 크기를 선택하도록 하였다. 또한 패치 간 유사도에 따라 홀을 채우는 방법을 한 번에 채우는 경우와 부분적으로 채우는 경우로 구분하였다. 이를 통해 오류의 발생을 줄이고 깊이 영상 기반 렌더링에서 가장 큰 문제가 되는 오류의 전파를 억제하였다. 실험을 통해 제안한 방법이 기존의 방법보다 시각적으로 자연스러운 가상 시점 영상을 생성하는 것을 확인하였다.