• Title/Summary/Keyword: Contact point

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THE BUDDHIST HERITAGE ON THE SILK ROAD: FROM GANDHARA TO KOREA

  • KHAN, M. ASHRAF
    • Acta Via Serica
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    • v.1 no.1
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    • pp.95-104
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    • 2016
  • The Silk Route in ancient times served as a link between the World's greatest civilizations and as a source of knowledge, art, religion and philosophy. This network of ancient caravan paths formed the first bridge between East and West, where two different civilizations came in contact with their respective cultural traditions and religious beliefs, as well as their scientific and technological achievements. One of the main routes of the Great Silk Route passed through the Karakoram, linking Kashgar with Kashmir and the Gandhara regions. The Karakoram Highway connects the Chinese province with Pakistan and follows the ancient Silk Route, which connected the Heartlands of Asia with the Western fringes and further beyond the entire continent of Europe. Evidences of the history of humankind, ranging from Pre-historic times to the spread of Buddhism from South Asia to China and the Far East, is depicted in the rocky cliffs on the waysides and on rough boulders scattered in the upper valley of the Indus River and its tributaries. The ancient trade routes also carried scholars, teachers, missionaries and monks of different beliefs and practices, who met and exchanged ideas. The Buddhists as well as Zoroastrians and other missionaries all followed the Silk Route, leaving permanent footprints of their passage. The ancient greater Gandhara is situated in the North-West of the Indian Sub-continent, with the steep mountain ranges of the Karakoram, the Pamir and the Hindu-Kush bordering it and the dry areas of Central Asia to its rear. A number of races from Central Asia migrated to Gandhara because of its mild climate and plentiful farm products and fruits. This area was an entry point of Western Culture into India and at the same times the exit point of Indian Culture, including Buddhism, to the West. In Gandhara, the diffusion of different cultures developed an art form, during the 1-7th centuries CE commonly known after its geographic name as "Gandhara Art". The Buddhism's route of introduction into China originated in Gandhara, then reached in Korea and Japan and other countries. The fame of Gandhara however, rested on its capital, "Taxila" which was a great centre of learning. From the time of the Achaemenians, down through Muslim period, Gandhara continued to establish and maintain a link between East & West, as shown by material evidences recovered from Taxila and other Buddhist centres of Gandhara during the course of archaeological excavations.

Accuracy of Digital Impression Made from Different Elastomeric Impression Materials: Three-Dimensional Superimpositional Analysis (치과용 탄성 인상재를 기반으로 채득된 디지털 모형의 정확성 연구: 3차원 중첩 분석)

  • Kim, Ki-Baek;Jung, Jae-Kwan;Kim, Jae-Hong
    • Journal of dental hygiene science
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    • v.14 no.2
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    • pp.94-100
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    • 2014
  • The purpose of this study was to evaluate the accuracy of digitized elastomeric impression materials of crown abutment, using non-contact white light scanner and virtual three-dimensional superimpositional analysis. The stone models and impressions were digitized white light scanner to create three-dimensional surface models. Stone models were used as CAD reference model (CRM). The resulting point clouds (ASC file) from digitization of impressions using converting software. Discrepancies between the points in the point clouds and CRM were measured by superimpositional software. Mean and standard deviation of values of discrepancies were analyzed by one-way ANOVA and multiple comparison (${\alpha}=0.05$). The mean discrepancy between the impressions for the extra-light body (XLB), light body (LB), and heavy body (HB) group were $5.10{\pm}1.45{\mu}m$, $6.30{\pm}1.87{\mu}m$, $9.80{\pm}1.52{\mu}m$, respectively. The different impression materials affected the digitization of impressions significantly (p<0.05). As a result, digitization of elastomeric impression materials on dental scanner was influenced by material sort.

Inferior Orbital Wall Reconstruction with Vascularized Partial Thickness Calvarial Bone Flap in Three Cases of Maxillary Tumor (혈행화된 부분층 두개골피판을 이용한 상악골 종양 적출 환자에서의 안와하벽 재건술 증례)

  • Shin, Sang Ho;Lee, Yoon Jung;Kim, Jun Sik;Kim, Nam Gyun;Lee, Kyung Suk
    • Archives of Craniofacial Surgery
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    • v.10 no.1
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    • pp.49-54
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    • 2009
  • Purpose: Inevitably, Maxillary structural defect follows maxillary cancer extirpation. Maxillary reconstruction is over every surgeon's head. Every physician tried to overcome limited donor site of craniofacial defect. We considered to suggest optimal method of inferior orbital wall defect in functional point as well as esthetic point. Methods: We performed wide excision of maxilla and vascularized partial thickness calvarial bone flap to reconstruct the defect from cancer extirpation in three cases. We select ipsilateral superficial temporal artery, vein and outer cortex of parietal bone flap as donor. And we applied bone flap as inferior orbital wall structure. The bony surface was wrapped with fascia to prevent direct contact between orbital contents and rough bony flap surface. Computed tomography image was checked during follolw up period. Results: We can observe these patients for over two years. In all three cases, We can get fair inferior orbital wall structure. Even though they got radiation therapy, there was no limitation of extraocular movements, no diplopia. no enophthalmos. Also there was minimal donor site morbidity. Conclusion: We suggest vascularized calvarial bone flap is practically excellent strategy for inferior orbital wall reconstruction.

A Study on Control of Sealing Robot for Cracks of Concrete Surface (콘크리트 표면 균열 실링을 위한 로봇의 제어 방법에 관한 연구)

  • Cho, Cheol-Joo;Lim, Kye-Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.2
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    • pp.481-491
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    • 2015
  • Since the crack in the surface of the concrete acts as the main reason influencing the life span of the structure, regular inspections and maintenance are required. The sealing required for maintenance of the concrete surface is a method of repairing the crack in the surface in the beginning, and is effective in preventing additional cracks and expansion that occurs with time. However, sealing on large sized structures such as tall buildings or bottom parts of bridges are difficult to ensure safety of the workers due to inadequate working environments. Due to this reason, the importance of the need for sealing automation for the maintenance of large sized concrete structures is emerging. This study proposes two control methods to apply robot systems to the sealing of cracks on the bottom parts of concrete bridges. First is the method of automatically tracking the trajectory of cracks. The robot gets the trajectory of the cracks using video information obtained from cameras. Comparing the previous several points and new point, the next point can be estimated. Thus, the trajectory of the crack can be tracked automatically. The other method is sealing by maintaining steady force to the contacting surface. The concrete surface exposed to an external environment for a long time gets an irregular roughness. If robots are able to carry out sealing while maintaining a steady contact force on these rough surfaces, complete equal sealing can be maintained. In order to maintain this equal force, a force control method using impedance is proposed. This paper introduces two developed control methods to apply to sealing robots, and conducts a Lab Test and Field Test after applying to a robot. Based on the test results, opinions on the possibilities of field application of the robot applied with the control methods are presented.

Reliability Prediction of Failure Modes due to Pressure in Solid Rocket Case (고체로켓 케이스 내압파열 고장모드의 신뢰도예측)

  • Kim, Dong-Seong;Yoo, Min-Young;Kim, Hee-Seong;Choi, Joo-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.6
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    • pp.635-642
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    • 2014
  • In this paper, an efficient technique is developed to predict failure probability of three failure modes(case rupture, fracture and bolt breakage) related to solid rocket motor case due to the inner pressure during the mission flight. The overall procedure consists of the steps: 1) design parameters affecting the case failure are identified and their uncertainties are modelled by probability distribution, 2) combustion analysis in the interior of the case is carried out to obtain maximum expected operating pressure(MEOP), 3) stress and other structural performances are evaluated by finite element analysis(FEA), and 4) failure probabilities are calculated for the above mentioned failure modes. Axi-symmetric assumption for FEA is employed for simplification while contact between bolted joint is accounted for. Efficient procedure is developed to evaluate failure probability which consists of finding first an Most Probable Failure Point(MPP) using First-Order Reliability Method(FORM), next making a response surface model around the MPP using Latin Hypercube Sampling(LHS), and finally calculating failure probability by employing Importance Sampling.

Adjustable Ghajar Guide Technique for Accurate Placement of Ventricular Catheters : A Pilot Study

  • Yoon, Sang-Youl;Kwak, Youngseok;Park, Jaechan
    • Journal of Korean Neurosurgical Society
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    • v.60 no.5
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    • pp.604-609
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    • 2017
  • Objective : An adjustable Ghajar guide is presented to improve the accuracy of the original Ghajar guide technique. The accuracy of the adjustable Ghajar guide technique is also investigated. Methods : The coronal adjustment angle from the orthogonal catheter trajectory at Kocher's point is determined based on coronal head images using an electronic picture archiving and communication system. For the adjustable Ghajar guide, a protractor is mounted on a C-shaped basal plate that is placed in contact with the margin of a burrhole, keeping the central $0^{\circ}$ line of the protractor orthogonal to the calvarial surface. A catheter guide, which is moved along the protractor and fixed at the pre-determined adjustment angle, is then used to guide the ventricular catheter into the frontal horn adjacent to the foramen of Monro. The adjustable Ghajar guide technique was applied to 20 patients, while a freehand technique based on the surface anatomy of the head was applied to another 47 patients. The accuracy of the ventricular catheter placement was then evaluated using postoperative computed tomography scans. Results : For the adjustable Ghajar guide technique (AGT) patients, the bicaudate index ranged from 0.23 to 0.33 ($mean{\pm}standard$ deviation [SD] : $0.27{\pm}0.03$) and the adjustment angle ranged from $0^{\circ}$ to $10^{\circ}$ ($mean{\pm}SD:5.2^{\circ}{\pm}3.2^{\circ}$). All the AGT patients experienced successful cerebrospinal fluid diversion with only one pass of the catheter. Optimal placement of the ventricular catheter in the ipsilateral frontal horn approximating the foramen of Monro (grade 1) was achieved in 19 patients (95.0%), while a suboptimal trajectory into a lateral corner of the frontal horn passing along a lateral wall of the frontal horn (grade 3) occurred in 1 patient (5.0%). Thus, the AGT patients experienced a significantly higher incidence of optimal catheter placement than the freehand catheterized patients (95.0% vs. 68.3%, p=0.024). Moreover, none of the AGT patients experienced any tract hemorrhages along the catheter or procedure-related complications. Conclusion : The proposed adjustable Ghajar guide technique, using angular adjustment in the coronal plane from the orthogonal trajectory at Kocher's point, facilitates accurate freehand placement of a ventricular catheter for hydrocephalic patients.

A Study on the Optimal Location of the Inclinometer and Strain Gauge in Small-Scale Underground Excavation (소규모 지하굴착에서 지중경사계와 변형률계의 최적 위치 선정에 대한 연구)

  • Gichun Kang;Jinuk Park;Byeongjin Roh;Jiahao Sun;Seong-Kyu Yun
    • Journal of the Korean Geosynthetics Society
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    • v.22 no.2
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    • pp.23-33
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    • 2023
  • Currently, there are cases in Korea where economic damage has occurred due to the ambiguity instrument installation and operation standards in the construction of temporary earth retaining wall, failing to prevent collapse of temporary earth retaining wall at the construction site in advance. Therefore, in this study, a numerical analysis was conducted to find the appropriate installation location of the inclinometer and strain gauge among the installed instruments shown in the design drawing of the temporary earth retaining wall. As a results, It was found that the installation position of the underground inclinometer is the corner of the retaining wall in the case of plane-deformation analysis, and the most displacement occurs in the center of the excavation surface in the case of 3D analysis. When the stress and moment are comprehensively analyzed, the corner is judged to be a vulnerable point. In the case of the strain gauge, In plane-deformation analysis and 3D analysis, the maximum bending stress occurred at the wale connection where the end of the strut and the counter strut are in contact. At this point, it is analyzed that it is necessary to focus on installing and managing the connection to prevent accidents from being vulnerable.

Comparative analysis of the in vivo kinetic properties of various bone substitutes filled into a peri-implant canine defect model

  • Jingyang Kang;Masaki Shibasaki;Masahiko Terauchi;Narumi Oshibe;Katsuya Hyodo;Eriko Marukawa
    • Journal of Periodontal and Implant Science
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    • v.54 no.2
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    • pp.96-107
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    • 2024
  • Purpose: Deproteinized bovine bone or synthetic hydroxyapatite are 2 prevalent bone grafting materials used in the clinical treatment of peri-implant bone defects. However, the differences in bone formation among these materials remain unclear. This study evaluated osteogenesis kinetics in peri-implant defects using 2 types of deproteinized bovine bone (Bio-Oss® and Bio-Oss/Collagen®) and 2 types of synthetic hydroxyapatite (Apaceram-AX® and Refit®). We considered factors including newly generated bone volume; bone, osteoid, and material occupancy; and bone-to-implant contact. Methods: A beagle model with a mandibular defect was created by extracting the bilateral mandibular third and fourth premolars. Simultaneously, an implant was inserted into the defect, and the space between the implant and the surrounding bone walls was filled with Bio-Oss, Bio-Oss/Collagen, Apaceram-AX, Refit, or autologous bone. Micro-computed tomography and histological analyses were conducted at 3 and 6 months postoperatively (Refit and autologous bone were not included at the 6-month time point due to their rapid absorption). Results: All materials demonstrated excellent biocompatibility and osteoconductivity. At 3 months, Bio-Oss and Apaceram-AX exhibited significantly greater volumes of formation than the other materials, with Bio-Oss having a marginally higher amount. However, this outcome was reversed at 6 months, with no significant difference between the 2 materials at either time point. Apaceram-AX displayed notably slower bioresorption and the largest quantity of residual material at both time points. In contrast, Refit had significantly greater bioresorption, with complete resorption and rapid maturation involving cortical bone formation at the crest at 3 months, Refit demonstrated the highest mineralized tissue and osteoid occupancy after 3 months, albeit without statistical significance. Conclusions: Overall, the materials demonstrated varying post-implantation behaviors in vivo. Thus, in a clinical setting, both the properties of these materials and the specific conditions of the defects needing reinforcement should be considered to identify the most suitable material.

Deposition of Poly(3-hexylthiophene)(P3HT) by Vapor Deposition and Patterning Using Self-Assembled Monolayers (Oxide 표면에 Self-Assembly Monolayers를 이용한 전도성 고분자 Poly(3-hexylthiophene)(P3HT) 증착 및 Patterning 연구)

  • Pang, Il-Sun;Kim, Hyun-Ho;Kim, Sung-Soo;Lee, Jae-Gab
    • Korean Journal of Materials Research
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    • v.18 no.12
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    • pp.664-668
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    • 2008
  • Vapor phase polymerization of a conductive polymer on a $SiO_2$ surface can offer an easy and convenient means to depositing pure and conductive polymer thin films. However, the vapor phase deposition is generally associated with very poor adhesion as well as difficulty when patterning the polymer thin film onto an oxide dielectric substrate. For a significant improvement of the patternability and adhesion of Poly(3-hexylthiophene) (P3HT) thin film to a $SiO_2$ surface, the substrate was pre-patterned with n-octadecyltrichlorosilane (OTS) molecules using a ${\mu}$-contact printing method. The negative patterns were then backfilled with each of three amino-functionalized silane self-assembled monolayers (SAMs) of (3-aminopropyl) trimethoxysilane (APS), N-(2-aminoethyl)-aminopropyltrimethoxysilane (EDA), and (3- trimethoxysilylpropyl)diethylenetriamine (DET). The quality and electrical properties of the patterned P3HT thin films were investigated with optical and atomic force microscopy and a four-point probe. The results exhibited excellent selective deposition and significantly improved adhesion of P3HT films to a $SiO_2$ surface. In addition, the conductivity of polymeric thin films was relatively high (${\sim}13.51\;S/cm$).

Operating Strategies for Family-Cooperative Activities (Pumasi) and a Cooperative Child Care Place as a Healthy Family Support Center's Project (건강가정지원센터의 가족품앗이 및 공동육아나눔터 사업운영 전략)

  • Cha, Sung-Lan
    • Journal of Family Resource Management and Policy Review
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    • v.16 no.2
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    • pp.187-210
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    • 2012
  • Pumasi and Cooperative Child Care Sharing have had positive results among participants and show possibilities of spreading out to the community in general. However, performance was not proved where it is clarified, and the experience of 23 local Healthy Family Support Centers have that ran the demonstration project were unable to be collected. It is the point of time when the initial backing up is important but the centers do not have the systematic support. Therefore, this research presents an effective management plan through qualitative research involving Pumasi participants and person in charge. The operation strategies by the stage of the project were as follows: First, in the beginning stage, the person in charge establishes the target and vision of the project. Second, when comprising the Pumasi team, it was necessary to consider their characteristics according to the team organization subjects. Third, it is necessary to extend the turn-off time and provide many programs so that the various populations can participate. Fourth, in the advertising step, word of mouth and individual contact needs to be utilized. Fifth, in a medium or small city or an urban-rural complex area, the person in charge should support the participants' Pumasi activities. Sixth, various programs such as a passive and active parent education program and Pumasi education program for the leader needs to be provided for the activation of Pumasi activities. Lastly, a cooperative child care sharing location needs to be constructed by the duality system of the base space and outer space. In this location, the inside play space for the children is essential.

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