• Title/Summary/Keyword: Internal thread

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Finite Element Stress Analysis in Supporting Bone according to Crest Module Shape of Fixture in Internal Connection System (내측연결 시스템에서 임플란트 고정체의 경부 형태에 따른 지지골에서의 유한요소 응력분석)

  • Park, Young-Nam;Kim, Hee-Jung;Oh, Sang-Ho;Chung, Chae-Heon
    • Journal of Dental Rehabilitation and Applied Science
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    • v.22 no.1
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    • pp.55-74
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    • 2006
  • The external contour of an implant can have significant effects on the load transfer characteristics and may result in different bone failure rates for different implant system. The purpose of this study was to investigate the effects of crest module shape and occlusal load direction on bone failure modes of five commercially available dental implant systems. Five different implant systems with internal connection; ITI (Model 1), Astra (Model 2), Bicon (Model 3), Friadent (Model 4), and Paragon (Model 5), comparable in size, but different in thread profile and cest module shapes, were compared using the finite element method. Conclusively, in the internal connection system of the implant-abutment connection methods, the stress-induced pattern at the supporting bone according to the abutment connection form had differenence among them, and implants with narrowing crestal module cross-sections at the top of the cortical bone created more favorable load transfer characteristics in this region. But it is considered that the future study is necessary about how this difference in the magnitude of the stress have an effect on the practical clinic.

A Study on Korean Traditional Medicine Side Effects Cases Described in Domestic Western Medical Journals in the Past 10 Years (10년간 국내 양방 의학 학술지에 게재된 한방치료 부작용 사례 고찰)

  • Lee, Myeong-hwa;Son, Byun-woo;Kim, Kyoung-min;Jeon, Soo-hyung;Kim, Young-kyun
    • The Journal of Internal Korean Medicine
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    • v.39 no.4
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    • pp.686-698
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    • 2018
  • Objectives: The aim of this study was to report the current status of the Korean traditional medicine side effects described in domestic western medical journals in the past 10 years. Methods: We searched for domestic western medical papers about Korean traditional medicine side effects cases from January 1, 2008, to August 31, 2017. Results: Thirty papers were selected from 31 studies. The number of papers of side effects caused by acupuncture was 21 (70%), by herbal medication was 7 (23%) and by thread lifting was 2 (7%). The number of papers of side effects caused by Korean medical doctors was 20 (66.8%), by non-medical persons including patients was 2 (6.6%), by herbal pharmacists was 1 (3.3%), by multiple practitioners, including Korean medical doctors, was 1 (3.3%), and by unknown persons was 6 (20%). Reported side effects were mostly mild, except for death and severe side effects. Conclusions: Studies of Korean traditional medicine side effects are short, and in-depth studies of stability are needed. These studies will improve the safety of the Korean traditional medicine.

Parallel Multithreaded Processing for Data Set Summarization on Multicore CPUs

  • Ordonez, Carlos;Navas, Mario;Garcia-Alvarado, Carlos
    • Journal of Computing Science and Engineering
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    • v.5 no.2
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    • pp.111-120
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    • 2011
  • Data mining algorithms should exploit new hardware technologies to accelerate computations. Such goal is difficult to achieve in database management system (DBMS) due to its complex internal subsystems and because data mining numeric computations of large data sets are difficult to optimize. This paper explores taking advantage of existing multithreaded capabilities of multicore CPUs as well as caching in RAM memory to efficiently compute summaries of a large data set, a fundamental data mining problem. We introduce parallel algorithms working on multiple threads, which overcome the row aggregation processing bottleneck of accessing secondary storage, while maintaining linear time complexity with respect to data set size. Our proposal is based on a combination of table scans and parallel multithreaded processing among multiple cores in the CPU. We introduce several database-style and hardware-level optimizations: caching row blocks of the input table, managing available RAM memory, interleaving I/O and CPU processing, as well as tuning the number of working threads. We experimentally benchmark our algorithms with large data sets on a DBMS running on a computer with a multicore CPU. We show that our algorithms outperform existing DBMS mechanisms in computing aggregations of multidimensional data summaries, especially as dimensionality grows. Furthermore, we show that local memory allocation (RAM block size) does not have a significant impact when the thread management algorithm distributes the workload among a fixed number of threads. Our proposal is unique in the sense that we do not modify or require access to the DBMS source code, but instead, we extend the DBMS with analytic functionality by developing User-Defined Functions.

A Study of Futuristic Materials in Contemporary Fashion

  • Kim, Yoon-Hee;Choi, Yoon-Mi
    • International Journal of Costume and Fashion
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    • v.7 no.1
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    • pp.22-31
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    • 2007
  • The systematic study of the future began with curiosity and imagination about the future; a unique trait of human mental effort-and this seems to be based on the idea that the future can be different depending on current choices or effort. In this sense, it would be seemly to encourage more interest and academic study on the progress of future fashion. In this study, we examine recent changes of fashion material; e.g. that which science and technology have more impact and importance in futuristic fashion since the 1990�s. The period analysed is from the1990's to the present and related data from recent fashion collections and fashion books has also been included The current prediction of the future is largely based on what was formed between the 19th Century and the 20th Century which has persisted until now and has been influenced by the view that science will play a bigger role in the future. This is especially reflected in fashion which chiefly represents material culture. New materials used for fashion are strong and permanently durable, in addition to being very light, thin, flexible, hygienic, ecological and comfortable to wear-almost like a second skin. These fashionable new materials roughly function in two different ways according to external and internal characteristics. First, they cause external change. Second, they exemplify or allow new functions. Examples of external change are the use of silver color, achromatic color, metallic material, smooth-to-the-touch shiny material and the use of luminous material. Examples of the extended function of clothing through the use of new materials are the use of conducting thread, the use of special material for blocking & opening and the use of material which changes colors as the surroundings change. These days, the use of new material which changes its appearance is a novelty unique to the fashion world but we also expect to witness the debut of diverse new materials with extended inner functions.

Rheological Analysis in a Spinning Process of a hollow fiber membrane

  • Jang, Moon-Seog
    • Proceedings of the Membrane Society of Korea Conference
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    • 1995.10a
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    • pp.5-9
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    • 1995
  • In the dry-jet-wet-spinning process of a hollow fiber membrane, the polymer solution is pumped into a coaxial tube, jet spinneret. The threadline emerging from the spinneret is stabilized by an internal coagulating medium(liquid or gas) as it emerges from the jet orifice. The nascent hollow thread is further stabilized in a quench bath as shown in Fig. 1. In this scheme, three mechanism of formatiota(temperature gradient, solvent evaporation, and solvent-nonsotvent exchange) can be combined. The changes which promote stabilization often play a dominant role in determining the ultimate fiber wall structure as well. Hence, in pratice, hollow fiber stabilization and development of membrane structure are commonly inseparable. However, fiber dimension(the inside diameter and wall thickness of the hollow fiber) is mainly a rheological problem and is determined by dope pumping rate, spinneret diatance from the coagulation bath, inner coagulant flow rate, and fiber draw-rate. Besides rheological phenomena play a prominent part in the final properties of the hollow fiber.

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Poring of WIPI HAL in Embedded Linux (리눅스 환경에서 WIPI를 지원하기 위한 HAL (Handset Abstraction Layer) 이식)

  • Park, Woo-Ram;Kim, Tae-Woong;Park, Chan-Ik
    • IEMEK Journal of Embedded Systems and Applications
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    • v.3 no.1
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    • pp.30-33
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    • 2008
  • This paper persents how to port HAL (Handset Abstraction Layer) on embedded Linux to support WIPI (Wireless Internet Platform for Interoperability). As smart phones are widespread nowdays, the operating system is changing from a simple kernel like Qualcomm REX OS to more feature-rich Linux kernel. For this reason, we investigate the internal structure of HAL on REX OS and design how to port it to embedded Linux. Careful analysis leads us to identify several porting issues such as thread support, graphical user interface. In addition, we describe some problems discovered during the implementation process and propose alternative architecture of HAL for WIPI on Linux.

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Privacy-Preserving Parallel Range Query Processing Algorithm Based on Data Filtering in Cloud Computing (클라우드 컴퓨팅에서 프라이버시 보호를 지원하는 데이터 필터링 기반 병렬 영역 질의 처리 알고리즘)

  • Kim, Hyeong Jin;Chang, Jae-Woo
    • KIPS Transactions on Computer and Communication Systems
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    • v.10 no.9
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    • pp.243-250
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    • 2021
  • Recently, with the development of cloud computing, interest in database outsourcing is increasing. However, when the database is outsourced, there is a problem in that the information of the data owner is exposed to internal and external attackers. Therefore, in this paper, we propose a parallel range query processing algorithm that supports privacy protection. The proposed algorithm uses the Paillier encryption system to support data protection, query protection, and access pattern protection. To reduce the operation cost of a checking protocol (SRO) for overlapping regions in the existing algorithm, the efficiency of the SRO protocol is improved through a garbled circuit. The proposed parallel range query processing algorithm is largely composed of two steps. It consists of a parallel kd-tree search step that searches the kd-tree in parallel and safely extracts the data of the leaf node including the query, and a parallel data search step through multiple threads for retrieving the data included in the query area. On the other hand, the proposed algorithm provides high query processing performance through parallelization of secure protocols and index search. We show that the performance of the proposed parallel range query processing algorithm increases in proportion to the number of threads and the proposed algorithm shows performance improvement by about 5 times compared with the existing algorithm.

FIT OF FIXTURE/ABUTMENT INTERFACE OF INTERNAL CONNECTION IMPLANT SYSTEM (내측연결 임플란트 시스템에서 고정체와 지대주 연결부의 적합에 관한 연구)

  • Lee Heung-Tae;Chung Chae-Heon
    • The Journal of Korean Academy of Prosthodontics
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    • v.42 no.2
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    • pp.192-209
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    • 2004
  • Purpose : The purpose of this study was to evaluate the machining accuracy and consistency of implant/abutment/screw combination or internal connection type. Material and methods: In this study, each two randomly selected internal implant fixtures from ITI, 3i, Avana, Bicon, Friadent, Astra, and Paragon system were used. Each abutment was connected to the implant with 32Ncm torque value using a digital torque controller or tapping. All samples were cross-sectioned with grinder-polisher unit (Omnilap 2000 SBT Inc) after embeded in liquid unsaturated polyester (Epovia, Cray Valley Inc). Then optical microscopic and scanning electron microscopic(SEM) evaluations of the implant-abutment interfaces were conducted to assess quality of fit between the mating components. Results : 1) Generally, the geometry of the internal connection system provided for a precision fit of the implant/abutment into interface. 2) The most precision fit of the implant/abutment interface was provided in the case of Bicon System which has not screw. 3) The fit of the implant/abutment interface was usually good in the case of ITI, 3I and Avana system and the amount of fit of the implant/abutment interface was similar to each other. 4) The fit of the implant/abutment interface was usually good in the case of Friadent, Astra and Paragon system. The case of Astra system with the inclined contacting surface had the most Intimate contact among them. 5) Amount of intimate contact in the abutment screw thread to the mating fixture was larger in assembly with two-piece type which is separated screw from abutment such as Friadent, Astra and Paragon system than in that with one-piece type which is not seperated screw from abutment such as ITI, 3I and Avana system. 6) Amount of contact in the screw and the screw seat of abutment was larger in assembly of Friadent system than in asembly of Astra system of Paragon system. Conclusion: Although a little variation in machining accuracy and consistency was noted in the samples, important features of all internal connection systems were the deep, internal implant-abutment connections which provides intimate contact with the implant walls to resist micro-movement, resulting in a strong stable interface. From the results of this study, further research of the stress distribution according to the design of internal connection system will be required.

The Effect of Gongjin-dan on Gliosis in Middle Cerebral Artery Occlusion (MCAO) Rats (공진단이 MCAO모델 흰쥐에서 gliosis 억제에 마치는 영향)

  • Seong, Kee-Moon;Hae, Rae-Kyong;Song, Bong-Keun
    • The Journal of Internal Korean Medicine
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    • v.30 no.4
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    • pp.674-684
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    • 2009
  • Objectives : In conditions of brain infarction, irreversible axon damage occurs in the central nerve system (CNS), because gliosis becomes a physical and a mechanical barrier to axonal regeneration. Reactive gliosis induced by ischemic injury such as middle cerebral artery occlusion is involved with up-regulation of GFAP and CD81. This study was undertaken to examine the effect of the Gongjin-dan (GJD) on CD81 and GFAP expression and its pathway in the rat brain following middle cerebral artery occlusion (MCAO). Methods : In order to study ischemic injuries on the brain, infarction was induced by MCAO using insertion of a single nylon thread, through the internal carotid artery, into a middle cerebral artery. Cresyl violet staining, cerebral infarction size measurement, immunohistochemistry and microscopic examination were used to detect the expression of CD81 and GFAP and the effect on the infarct size and pyramidal cell death in the brain of the rat with cerebral infarction induced by MCAO. Also, c-Fos and ERK expression were measured to investigate the signaling pathway after GJD administration in MCAO rats. Results : Measuring the size of cerebral infarction induced by MCAO in the rat after injection of GJD showed the size had decreased. GJD administration showed pyramidal cell death protection in the hippocampus in the MCAO rat. GJD administration decreased GF AP expression in the MCAO rat. GJD administration decreased CD81 expression in the MCAO rat. GJD administration induced up-regulation of c-FOS expression compared with MCAO. GJD administration induced down-regulation of ERK expression compared with MCAO. Conclusion : We observed that GJD could suppress the reactive gliosis, which disturbs the axonal regeneration in the brain of a rat with cerebral infarction after MCAO by controlling the expression of CD81 and GFAP. The effect may be modulated by the regulation of c-Fos and ERK. These results suggest that GJD can be a candidate to regenerate CNS injury.

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A Study on Physical and Mechanical Properties of Sawdustboards combined with Polypropylene Chip and Oriented Thread (폴리프로필렌사(絲)칩과 배향사(配向絲)를 결체(結締)한 톱밥보드의 물리적(物理的) 및 기계적(機械的) 성질(性質)에 관(關)한 연구(硏究))

  • Suh, Jin-Suk;Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
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    • v.16 no.2
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    • pp.1-41
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    • 1988
  • For the purpose of utilizing the sawdust having poor combining properties as board raw material and resulting in dimensional instability of board, polypropylene chip (abbreviated below as PP chip) or oriented PP thread was combined with sawdust particle from white meranti(Shorea sp.). The PP chip was prepared from PP thread in length of 0.25, 0.5, 1.0 and 1.5 cm for conventional blending application. Thereafter, the PP chip cut as above was combined with the sawdust particle by 3, 6, 9, 12 and 15% on the weight basis of board. Oriented PP threads were aligned with spacing of 0.5, 1.0 and 1.5cm along transverse direction of board. The physical and mechanical properties on one, two and three layer boards manufactured with the above combining conditions were investigated. The conclusions obtained at this study were summarized as follows: 1. In thickness swelling, all one layer boards combined with PP chips showed lower values than control sawdustboard, and gradually clear decreasing tendendy with the increase of PP chip composition. Two layer board showed higher swelling value than one layer board, but the majority of boards lower values than control sawdustboard. All three layer boards showed lower swelling values than control sawdustboard. 2. In the PP chip and oriented thread combining board, the swelling values of boards combining 0.5cm spacing oriented thread with 1.0 or 1.5cm long PP chip in 12 and 15% by board weight were much lower than the lowest of one or three layer. 3. In specific gravity of 0.51, modulus of rupture of one layer board combined with 3% PP chip showed higher value than control sawdustboard. However, moduli of rupture of the boards with every PP chip composition did not exceed 80kgf/cm2, the low limit value of type 100 board, Korean Industrial Standard KS F 3104 Particleboards. Moduli of rupture of 6%, 1.5cm-long and 3% PP chip combined boards in specific gravity of 0.63 as well as PP chip combined board in specific gravity of 0.72 exceeded 80kgf/$cm^2$ on KS F 3104. Two layer boards combined with every PI' chip composition showed lower values than control sawdustboard and one layer board. Three layer boards combined with.1.5cm long PP chip in 3, 6 and 9% combination level showed higher values than control sawdustboard, and exceeded 80kgf/$cm^2$ on KS F 3104. 4. In modulus of rupture of PP thread oriented sawdustboard, 0.5cm spacing oriented board showed the highest value, and 1.0 and 1.5cm spacing oriented boards lower values than the 0.5cm. However, all PP thread oriented sawdustboards showed higher values than control saw-dustboard. 5. Moduli of rupture in the majority of PP chip and oriented thread combining boards were higher than 80kgf/$cm^2$ on KS F 3104. Moduli of rupture in the boards combining longer PP chip with narrower 0.5cm spacing oriented thread showed high values. In accordance with the spacing increase of oriented thread, moduli of rupture in the PP chip and oriented thread combining boards showed increasing tendency compared with oriented sawdustboard. 6. Moduli of elasticity in one, two and three layer boards were lower than those of control sawdustboard, however, moduli of elasticity of oriented sawdustboards with 0.5, 1.0 and 1.5cm spacing increased 20, 18 and 10% compared with control sawdustboard, respectively. 7. Moduli of elasticity in the majority of PP chip and oriented thread combining boards in 0.5, 1.0 and 1.5cm oriented spacing showed much higher values than control sawdustboard. On the whole, moduli of elasticity in the oriented boards combined with 9% or less combination level and 0.5cm or more length of PP chip showed higher values than oriented sawdustboard. The increasing effect on modulus of elasticity was shown by the PP chip composition in oriented board with narrow spacing. 8. Internal bond strengths of all one layer PP chip combined boards showed lower values than control sawdust board, however, the PP chip combined boards in specific gravity of 0.63 and 0.72 exceeded 1.5kgf/$cm^2$, the low limit value of type 100 board and 3kgf/$cm^2$, type 200 board on KS F 3104, respectively. And also most of all two, three layer-and oriented boards exceeded 3kgf/$cm^2$ on KS F. 9. In general, screw holding strength of one layer board combined with PP chip showed lower value than control sawdustboard, however, that of two or three layer board combined with PP chip did no decreased tendency, and even screw holding strength with the increase of PP chip composition. In the PP chip and oriented PP thread combining boards, most of the boards showed higher values than control sawdustboard in 9% or less PP chip composition.

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