• 한국유기농업학회지
• /
• 제11권1호
• /
• pp.55-66
• /
• 2003

본 연구에서는 음식물쓰레기와 축분의 vermicomposting 처리로 얻어지는 지렁이 분립을 이용하여 채소의 육묘상토 자재로서의 이용가능성을 조사하기 위해, 시판상토 100％, 지렁이분립 100％, 지렁이분립 50％ ＋ vermiculite 50％, 지렁이분립 50％ + Perlite 50％ 및 지렁이분립 40％ ＋ vermiculite 30％ ＋ perlite 30％의 각각 다른 지렁이분립 혼합비율이 토마토(Lycopersicum esculentum Mill.) 유묘의 생육에 미치는 영향을 조사하였다. 토마토 생육 2주째까지는 시판상토구가 전 처리구에서 초장, 엽수, 경경, 엽중, 경중, 지상부중, 근중 및 생물수량이 가장 높았지만, 이후부터는 지렁이 분립 100％구가 다른 처리구보다 유의하게 높았으며 (p<0.05), 시판상토구에 비해서도 양호한 생육을 나타내었다. 지렁이 분립과 Vermiculite를 혼합한 구는 시판상토구와 유사한 생육을 나타내었다. 한편 생물수량의 상대생장율(BYRGR), 지상부 무게의 상대생장율(RGR) 및 지하부무게의 상대생장율(RWGR)은 생육 4주 째까지 지렁이 분립 100％ 구가 다른 처리구 보다 유의하게 높았다(P<0.05).

• 한국콘텐츠학회논문지
• /
• 제15권1호
• /
• pp.308-315
• /
• 2015

본 연구는 3D 프린터를 이용하여 통풍이 원활하고 위생적이며 선명한 방사선영상을 구할 수 있는 그물형 손목 부목을 제작하고자 하였다. 스캐너는 의료용 다중단층영상장치(MDCT)를 이용했으며, 3D 프린터 기기는 용융 적층 조형술(fused deposition modeling, FDM)의 프린팅 방식을 이용했다. 소재는 분해성 플라스틱 (poly lactic acid, PLA)을 사용하였다. 손목의 3 차원 볼륨렌더링은 MDCT에서 획득된 단층영상으로 구현하였다. 구현된 손목 3 차원 영상을 바탕으로 가상의 그물형 부목 모형을 디자인하고 출력하였다. 그 결과 3D 프린터로 출력된 부목이 기존 부목보다도 우수한 방사선 손목영상을 획득할 수 있었으며 가려움증 및 비위생적인 단점을 개선하고 부목 해체 작업이 용이하였다. 결론적으로 본 연구에서 모델링된 3D 부목 모형은 향후 3D 프린팅 부목 제작에 기초자료로 활용할 수 있으며 환자들의 실생활에 도움을 줄 것으로 기대한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제29권4호
• /
• pp.239-244
• /
• 2003

The common errors in preoperative treatment plan for the orthognathic surgery can be occurred during cast impression, cast mounting procedure with face-bow transfer, surgical stent fabrication, and so on. One of the most common errors exists during mounting process of the model on the articulator. Accurate mounting of dental casts to articulator should be achieved by transferring the 3-dimensional spatial relationship of the maxillary arch to an articulator. A face-bow is used for transfer this relationship to articulator, usually by relating the face-bow to a plane of reference of maxillary cast. The purpose of this study is evaluation of the accuracy of face-bow transferring of maxillary model to the articulator. The maxillary casts of thirty patients for orthognathic surgery were mounted on articulator with an face-bow instrument. The relationship of occlusal plane angle to Frankfort horizontal plane relations were compared the cephalogram with the cast-mounted articulator. As a result of this study, the significant difference between the maxillary occlusal planes angle in the cephalogram and articulator were found. The results were followed, 1. The mean occlusal plane angle in cast-mounted articulator was $13.5^{\circ}\;(SD{\pm}5.4)$. 2. The mean occlusal plane angle in cephalogram was $10.4^{\circ}\;(SD{\pm}4.3)$. 3. The mean difference of occlusal plane angle between cast-mounted articulator and cephalogram was $3.3^{\circ}\;(SD{\pm}4.6)$. According to the result, we should suggest that the occlusal plane angle to Frankfort plane in cast-mounted articulator is more steeper than that of cephalogram. And then, maxillofacial surgeon should try to get a more predictable result by suggesting the proper correction method and mounting the cast accurately.

• Journal of the Korean Data and Information Science Society
• /
• 제24권6호
• /
• pp.1297-1307
• /
• 2013

차량 망을 위해 개발된 다수의 멀티-홉 응용들은 근접한 이웃 차량들을 발견하거나 어떤 지리적 지역 내에 위치하는 다른 차량들에게 유용한 트래픽 정보를 전파하기 위한 수단으로 방송을 사용한다. 그러나 일반적인 방송 메커니즘은 지나치게 많은 패킷 방송에 기인하여 링크 계층에서 높은 수준의 경쟁과 충돌이 발생하는 방송 폭풍 문제를 유발시킬 수도 있다. 방송 폭풍 문제를 해결하기 위하여, 이 논문에서는 안전 관련 긴급 메시지를 전파하는 RPB-MACn 기반 차량 방송 알고리즘인 LV-CAST (the Last Vehicle-based broad CAST)를 제안한다. 제안하는 LV-CAST에서는 긴급 메시지를 전송하는 차량으로부터 그 긴급 메시지를 수신한 노드의 바로 뒤따라오는 노드까지 1홉 연장거리를 계산하여 전송범위 내의 마지막 노드를 식별하고, 그 마지막 차량만이 긴급 메시지를 재방송하도록 한다. 제안하는 LV-CAST의 성능을 모의실험으로 평가하고 다른 메시지 전파 알고리즘들과 비교한다.

• 한국산림과학회지
• /
• 제10권1호
• /
• pp.17-27
• /
• 1970

소나무 묘목을 이용하여 포지에서 비료 3요소 시험을 $3^3$요인 시험으로 S반복을 실시하여 1963년부터 1966까지 4년간 실시한 결과는 다음과 같다. 1. 소나무는 삼요소중 질소비료에 대하여 가장 비효가 컸으며 질소, 인산, 가리의 순위였으나 2. 3차년도 이후는 Needle cast가 발병하여 가리에 대하여 고도의 비효가 있었으며 인산에 대하여는 0.5%의 유의성이 있었다. 3. 가리는 소나무 생장에는 질소와 같이 크게 비효를 나타내지 못하였으나 Needle cast가 만연된 후에는 가리의 시용구에서는 비효를 나타 내었다. 4. 즉 소나무에 있어서는 Needle cast 발병전에는 질소 및 인산의 비효가 크게 나타났으며 가리의 시용구가 신장 생장에는 크게 영향을 주지 못했으나 건묘로서 내병성이 강하였으므로 결과적으로 비효가 크게 인정되었다. 5. Needle cast 발병 전에는 가리의 비효가 나타나지 않았으나 발병 후에는 질소나 인산보다도 가리의 시비효과가 크게 인정되었으며 그 효과는 가리, 인산, 질소의 순위이었다.

• 한국주조공학회지
• /
• 제29권3호
• /
• pp.120-127
• /
• 2009

The characterestics of high Si-high Mo ductile cast iron, high Si-high Mo C.V. cast iron and Ni-resist cast iron were compared and evaluated. The nodule count of the last one was lower and the nodularity was higher than those for the first one, respectively. The first two had ferritic matrices with small amounts of molybdenum carbides. The first one had the highest tensile strength and the last one the lowest elongation. This had the highest high temperature strength and that of the second one was greatly increased from the room temperature strength. The volumes of the first two were decreased during cooling and that of the last one changed little. The thermal expansion coefficient of the last one was the highest and the first one the lowest. During high temperature oxidation, even though the volume of the first one was increased, the weight was decreased and the volume and weight of the second one were increased. The change of the increased weight of the last one was more than that of thickness.

• Restorative Dentistry and Endodontics
• /
• 제19권1호
• /
• pp.64-72
• /
• 1994

Zinc Phosphate Cement hand been used for about more than 100 years in luting of cast gold inlay. But many scientists had been trying to develop the new form of luting agent because the ZPC hand shown the lack of adhesiveness on the tooth structure and the toxicity to the pulp tissue. Recently many researches about the surface treatment of the cast body are being done to increase the adhesion of cement to it. The conventional Class I gold inlays were fabricated in the 20 permanent molars. After the internal surface of the cast body was sandblasted with $Al_2O_3$ particles and was tin-plated, the inlays were cemented with adhesive cement [G I cement and resin cement(Super-Bond & $Panavia_{EX}$)] and the evaluation on the adhesion pattern, adhesive strength and the fracture pattern of the adhesive cast gold inlay was compared to that of the cast gold inlay cemented conventionally with ZPC. The results were as follows : 1. The surface roughness of the cast body was increased significantly after sandblasting with the $Al_2O_3$ particles and the tin oxide layer, which was consisted of round particles, came into being. 2. The bond strength was in the order of Super-Bond, ZPC, Fuji I, $Panavia_{EX}$ group. The group cemented with Super-Bond showed statistically greater strength than the other groups(p<0.05). 3. The group cemented with ZPC was fallen apart by principal adhesion failure and that with Fuji I was by complete adhesion failure. But the group with Super-Bond showed pricncipal cohesive failure pattern and in the group with $Panavia_{EX}$, complete cohesive fracture pattern was shown and small protion of tooth structure was fractured out with cast body and the fractured surface showed the figure just as the enamel prism. 4. Various gaps were shown at the pulpal side regardless of little gap at the side walls of the cavity in all groups. Only the Super-Bond was attached to the tooth structure and the other cements were detached from both the tooth and the cast body.

• The Journal of Advanced Prosthodontics
• /
• 제13권3호
• /
• pp.127-135
• /
• 2021

Purpose. The aim of this study is to compare the hardness according to the conditions of metal alloys. Moreover, the correlation between the cast crown hardness before and after wear testing and the degree of wear for each dental alloy was assessed. Materials and Methods. Cast crowns of three metal alloys (Co-Cr, gold, and Ni-Cr alloys) opposing smooth-surface monolithic zirconia were used. The Vickers microhardness of the ingot (which did not undergo wear testing) and the cast crown before and after wear testing were measured for each alloy. Two-way ANOVA and Scheffé tests were used to compare the measured hardness values. Moreover, the Pearson correlation coefficient was used to evaluate the relationship between the surface hardness and the wear of the cast crown (α=.05). Results. There was no significant difference in the hardness before and after wear testing for the gold alloy (P>.05); however, the hardness of the worn surface of the cast crown increased compared to that of the cast crown before the wear tests of Ni-Cr and Co-Cr alloys (P<.05). Furthermore, there was no correlation between the wear and hardness of the cast crown before and after wear testing for all three metal alloys (P>.05). Conclusion. There was a significant difference in hardness between dental alloys under the same conditions. No correlation existed between the surface hardness of the cast crown before and after wear testing and the wear of the cast crown.

• 한국주조공학회지
• /
• 제26권3호
• /
• pp.123-128
• /
• 2006

Mechanical and thermal properties of spray-cast hypereutectic Al-20wt.%Si-xwt.%Fe alloys (x=0, 1, 3, 5) were investigated. After the spray-casting, hot extrusion was performed at $400^{\circ}C$. Intermetallic compound (${\beta}-Al_5FeSi$) and primary Si are observed in the spray-cast aluminum alloys. The size of primary Si and intermetallic compound of the spray-aluminum alloys became finer and more uniformly distributed than that of the permanent mold cast ones. Ultimate tensile strength of the spray-cast aluminum alloys increased by increasing Fe contents, but that of the permanent mold cast aluminum alloys decreased by increasing Fe contents possibly due to increased amount of coarse intermatallic compound. The coefficient of thermal expansion (CTEs) of the aluminum alloys became lower with finer primary Si and intermetallic compound, and this is attributed to the increased amount of interfacial area between the aluminum matrix and the phases of finer Si and intermetallic compound.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제5권6호
• /
• pp.1113-1132
• /
• 2011

In wireless sensor networks (WSNs), most energy saving asynchronous MAC protocols are custom tailored for unicast communications only. However, broadcast protocols are very commonly used in WSNs for a variety of functionalities, such as gathering network topology information, event monitoring and query processing. In this paper, we propose a novel low-power asynchronous broadcast MAC protocol called Alarm Broadcast (A-CAST). A-CAST employs the strobe preamble that specifies the residual waiting time for the following data transmission. Each receiver goes back to sleep upon hearing the strobe preamble for the residual time duration, to conserve energy and to wake up just before data transmission starts. We compute the energy consumption of A-CAST via rigorous mathematical analysis. The analytic results show that A-CAST outperforms B-CAST, a simple broadcast extension of the well-known B-MAC. We also implement A-CAST on sensor motes and evaluated its performance through real experiments. Our experimental results show that A-CAST reduces the energy consumption by up to 222% compared to the previously proposed protocols.