• Title/Summary/Keyword: 견고성 고정

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The Effect of Splinting Methods on the Rearrangement of Periodontal Fibers after Tooth Movement in Adult Dogs (치아이동 후 고정방법이 성견 치주인대 섬유의 재배열에 미치는 영향)

  • Lee, Kr-Heon;Hwang, Hyeon-Shik
    • The korean journal of orthodontics
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    • v.27 no.5 s.64
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    • pp.825-837
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    • 1997
  • The purpose of this study was to evaluate the effect of splinting methods on the rearrangement of periodontal fibers after experimental tooth movement. Orthodontic force was applied by placing closed coil spring between upper third incisor and canine in seven dogs, weighing 20 kg or more. After 3 weeks of force application, 0.0215 inch multistrand wire and polyethylene ribbon were bonded to each side, as a flexible and rigid splinting respectively in 6 experimental animals. The remaining one served as a control. Each two animals were sacrificed at 4, 8 and 12 weeks after splinting respectively and prepared histologically for hematoxylin-eosin and Masson's trichrome staining. The results of this study were obtained as follows: 1. After tooth movement, periodontal space was narrowed and periodontal titers were thick on pressure side while elongated fibers were observed on tension side. 2. After 4 weeks of retention, the rearrangement of periodontal fibers was observed in the flexible splinting group, but not in the rigid splinting group. 3. After 8 weeks of retention, the rearrangement of periodontal titers was observed in both groups, but the difference could not be detected between two groups. 4. During the retention period, the rearrangement of periodontal fibers was faster in tension side than in pressure side. These results show that the rearrangement of periodontal fibers is also obtained by rigid splinting after tooth movement. It is suggested that the rigid splinting by polyethylene ribbon can be used as a way of postorthodontic retention.

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Studies on Whole Cell Immobilized Glucose Isomerase - I. Preparation and Properties of Whole Cell Immobilized Glucose Isomerase - (포도당 이성화 효소의 세포 고정화에 관한 연구 - I. 세포 고정화 효소의 제조와 성질 -)

  • Ahn, Byung-Yoon;Byun, Si-Myung
    • Korean Journal of Food Science and Technology
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    • v.11 no.3
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    • pp.192-199
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    • 1979
  • With cells of Streptomyces spp K-45 isolated from soil, the immobilization of glucose isomerase by a series of treatments ; heat, carefully manipulated drying, extrusion with a thickening agent, and glutaraldehyde-induced crosslinking, was presented. This was aimed to obtain a mechanically stable form of whole cell containing glucose isomerase. The resulted pellet form had a good mechanical strength, compared with a commercial product, and showed 26 % of the activity recovery. The specific activity was 48.1 units per g of the dry material. The immobilized glucose isomerase generally showed properties similar to those of the soluble enzyme ; optimal pH at $7.5{\sim}9.0$, optimal temperature at $80{\sim}85^{\circ}C$, activation energy of 10.9 kcal/mole, and $K_m$ for glucose of 10.9M. The immobilized enzyme was very thermostable and pH stable.

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Case Stories of Microgravity Survey for Shallow Subsurface Investigation (고정밀 중력탐사를 이용한 천부 지질구조 조사 사례)

  • Park Yeong-Sue;Rim Hyoungrae;Lim Mutaek;Koo Sung Bon;Kim Hag Soo;Oh Seok Hoon
    • 한국지구물리탐사학회:학술대회논문집
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    • 2005.05a
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    • pp.181-186
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    • 2005
  • Gravity method produces subsurface density distribution, which is direct information of soundness of basement. Therefore, microgravity is one of the most effective method for detections of limestone cavities, abandoned mine-shafts and other tunnels, The paper show the effectiveness of microgravity by three different field cases.

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THE INITIAL TISSUE CHANGE TO THE IMMEDIATE ORTHODONTIC FORCE FOLLOWING BUCCAL HORIZONTAL SUBAPICAL OSTEOTOMY OF MAXILLA (상악골 협측 수평 골절단술 직후 교정력에 의한 초기 치아주위 조직반응)

  • Hong, Kwang-Jin;Ahn, Byoung-Keun
    • The korean journal of orthodontics
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    • v.25 no.1 s.48
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    • pp.101-110
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    • 1995
  • The purpose of this study was to observe the tissue response to the orthodontic force applied immediately after buccal horizontal subapical osteotomy of maxilla. Five mongrel cats weighing about 2.5 Kg were used for this experiment. The left upper canine and premolar of each cat served as a experimental side and the right ones as a control side. On the experimental side, a 100gm orthodontic force was applied between the upper canine and premolar immediately after the osteotomy. On the control side, the same orthodontic force was applied without the osteotomy. After 7days, the experimental animals were sacrificed. The results were as follows: 1. In the pressure zones of the experimental group, significant increase of osteoclasts and direct resolution along the alveolar bone surface was observed as compared with those of the control group. 2. In the pressure 2ones of the experimental group, a less extensive hyalinized zone was observed than those of the control group. 3. In the pressure zones of both group, no root resorption was found. 4. Tn the tension zones of the experimental group, new bone deposition increased along the alveolar bone surface as compared with those of the control group. In conclusion, the results suggest the possibility that early orthodontic treatment after orthognathic surgery may have some benefits if the stability of the repositioned segment at surgery is secured.

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Studies on Whole Cell Immobilized Glucose Isomerase - II. Operational Studies on the Batchwise and Continuous Isomerization of D-Glucose - (포도당 이성화 효소의 세포 고정화에 관한 연구 - 제 2 보 : 회분식 및 연속 반응조를 사용한 포도당의 이성화 -)

  • Ahn, Byung-Yoon;Byun, Si-Myung
    • Korean Journal of Food Science and Technology
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    • v.11 no.4
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    • pp.249-257
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    • 1979
  • Using the whole cell immobilized glucose isomerase which was prepared in the previous work (Korean J. Food Sci. & Technol., 11(3), 192 (1979), the specific activity of the immobilized enzyme was 48.1 units in the batch reaction system and 114 units in the continuous reaction system per g of matrix, respectively. In the continuous reactor the voidity was 0.36, which was suitable for the packed bed reactor. This immobilized enzyme showed a good operational stability of 115 days of half life which was sufficient for the continuous operation. The experimental result showed that 55 % of the substrate was converted to the product in the packed bed reactor. The productivity was dependent on the flow rate, column geometry, enzyme loading, and substrate concentration. An intrapaticle diffusion was observed by the effectiveness factor of 0.75 and interparticle diffusion by the decrease of Km' with increasing the superficial velocity.

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Identifying Bridging Nodes and Their Essentiality in the Protein-Protein Interaction Networks (단백질 상호작용 네트워크에서 연결노드 추출과 그 중요도 측정)

  • Ahn, Myoung-Sang;Ko, Jeong-Hwan;Yoo, Jae-Soo;Cho, Wan-Sup
    • Journal of Korea Society of Industrial Information Systems
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    • v.12 no.5
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    • pp.1-13
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    • 2007
  • In this research, we found out that bridging nodes have great effect on the robustness of protein-protein interaction networks. Until now, many researchers have focused on node's degree as node's essentiality. Hub nodes in the scale-free network are very essential in the network robustness. Some researchers have tried to relate node's essentiality with node's betweenness centrality. These approaches with betweenness centrality are reasonable but there is a positive relation between node's degree and betweenness centrality value. So, there are no differences between two approaches. We first define a bridging node as the node with low connectivity and high betweenness value, we then verify that such a bridging node is a primary factor in the network robustness. For a biological network database from Internet, we demonstrate that the removal of bridging nodes defragment an entire network severally and the importance of the bridging nodes in the network robustness.

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Production of Sorbitol Using Dried and Immobilized Zymomonas mobilis (건조 고정화 Zymomonas mobilis에 의한 sorbitol 생산)

  • 박철진;장기효전억한
    • KSBB Journal
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    • v.7 no.2
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    • pp.144-148
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    • 1992
  • The purpose of this study is to develop a continuous process for sorbitol production using dried Zymomonas mobilis immobilized in K-carrageenan. The methods of glularaldehyde cross-linking of enzymes in CTAB (celyltrimetylammoniumbromide) treated cells immobilized in K-carrageenan showed stability for the production of sorbitol for 30 days of operation. K-carrageenan beads entrapping permeabilized cells were dried to Improve bead rigidity and storage stability. A semi-batch process with dry beads was carried out and only a small loss of enzyme activity (less than 8%) was observed during 72h. The value of Vmax for the dry K-carrageenan beads was found to be one half or that for free cells. It was shown that the productivities of the continuous process with wet K-carrageenan beads and dry beads at a dilution rate 0.1h-1 were 3.4g/L-h and 2.88h/L-h, respectively.

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Magnetic Levitated Micro Positioning System; Part 1: Design (자기부상을 이용한 초정밀 위치작동기의 설계)

  • 박기환;김수현;곽윤근
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.04a
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    • pp.401-405
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    • 1994
  • 위치작동기의 정밀도를 결정하는 중요한 인자인 마찰력을 없애기 위하여 자기부상을 이용한 초정밀 시스템을 설계한다. 자기부상시스템은 근본적으로 불안정한 성질을 갖고 있으므로 작동기의 안정성을 증가시킬수 있 는 자기회로설계가 종요하다. 제안된 자기부상 위치작동시스템은 전자석을 고정하고 영구자석을 움직일 수 있게하여, 간단하고 견고한 위치작동기가 설계되고록 상호간의 자기력을 이용한 Antagonistic 구조를 채택한다. 그리고 시스템의 동적모델을 구하여 안정성을 검토한다.

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Provable Security of Key Derivation Functions Based on the Block Ciphers (블록암호 기반 키유도함수의 증명가능 안전성)

  • Kang, Ju-Sung;Yi, Ok-Yeon;Youm, Ji-Sun
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.20 no.4
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    • pp.3-16
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    • 2010
  • Key derivation functions are used within many cryptographic systems in order to generate various keys from a fixed short key string. In this paper we survey a state-of-the-art in the key derivation functions and wish to examine the soundness of the functions on the view point of provable security. Especially we focus on the key derivation functions using pseudorandom functions which are recommended by NISI recently, and show that the variant of Double-Pipeline Iteration mode using pseudorandom permutations is a pseudorandom function. Block ciphers can be regarded as practical primitives of pseudorandom permutations.

Patellar fracture after transverse screw fixation in sports athletes - A case report - (운동선수에서 횡방향 나사 고정 후 발생한 슬개골의 골절 - 증례 보고 -)

  • Ra, Ho Jong;Kim, Sung Tae;Ha, Jeong Ku;Kim, Jin Goo
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.10 no.2
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    • pp.109-112
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    • 2011
  • Anatomical reduction and strong fixation in displaced patella fracture are needed for restoration of knee function and strength and early range of motion exercise. According to the type of fracture and various operational methods, their many complications have been reported. We report 2 cases of transverse patella fracture which were caused by transverse screw fixation in longitudinal patella fracture and fracture of bipartite patella in athletes.

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