• Title/Summary/Keyword: Jaw

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Stduy on the Dynamic Gripping Force of a 3-Jaw Chuck (3-죠오 척의 동적 파악력에 관한 연구)

  • Park, Tae-Won;M. Tsutsumi;I. Tokasiki
    • Journal of the Korean Society for Precision Engineering
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    • v.8 no.4
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    • pp.126-136
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    • 1991
  • In order to reduce the possibilities of personnel injuries and damages to machines and to obtaim higher efficiency and machining accuracy in the manufacturing system, the chucking technology has recentry become important. The chucking technology of work greatly affects both the grometrical accuracy and fonctional performance of the workpiece. In this study, the dynamic gripping force of a 3-jaw power chuck is investigated on the factors of the shape of jaw and the shape of workpiece. From this investigation, the following observations are obtained. 1) The higher stiffness of workpiece is, the higher decrease of dynamic gripping force is. 2) The nearer to the root of jaw is, the higher decrease of dynamic gripping force is. 3) The centrifugal force of affectting the decrease of dynamic gripping force has to be considered in the centrifugal force of affecting jaw.

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Integration Forming Technology based on Cold Hot Forging of Clutch Jaw Parts for Farm Machinery (냉열간 단조기술을 적용한 농기계용 클러치 Jaw 부품 일체화 성형기술)

  • Park, Dong-Hwan;Han, Seong-Chul
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.5
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    • pp.489-495
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    • 2015
  • Forging is a manufacturing process involving the shaping of metal using localized compressive forces and the process of deforming metal into a predetermined shape using certain tools and press according to the temperature. Forging provides stronger metal parts than that possible by casting or machining. Conventional clutch jaw parts have been developed through cold forging and precision machining; however, fabrication of integral clutch jaw parts for farm machinery has not been reported yet. These parts were developed by applying a complex forging technology combining cold and hot forging. The integrated forming technology proposed in this study will be useful for reducing the lead-time for manufacturing, improving the accuracy of products, and eliminating the welding process.

A Study on a Modeling of the Inhibitory Reflex Mechanism of Jaw Muscle Induced by Electrical Stimulation (전기자극에 대한 턱근육의 억제반사 메카니즘의 모델링에 관한 연구)

  • 김성환;김태훈;조일준;유세근
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.9
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    • pp.560-567
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    • 2003
  • EMG recordings of the electrical activity of muscle have proved to be a valuable tool in studying muscle function and reflex activity. SP(silent period) is elicited by a electrical stimulation on the chin during isometric contraction of jaw muscle. This paper proposes a model of the inhibitory reflex mechanism of jaw muscle after electrical stimulation. The SPs of jaw muscle after a electrical stimulation to the chin were divided into SP1 and SP2. SP1 is produced by the activation of periodontal receptors. The activation of nociceptors contributes to the SP2. As a result, the EMG signal generated by a proposed a model of inhibitory reflex mechanism is similar to real both EMG signal including SP1 and SP2. The present study have shown differences of SP1 and SP2 induced by inhibitory reflex mechanism.

FABRICATION OF SURGICAL SPLINT BY USING OF SURGICAL JAW RELATOR (Surgical Jaw Relator를 이용한 Surgical splint의 제작)

  • Yang, Sang-Duck
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.27 no.2
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    • pp.188-195
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    • 2005
  • After making the surgical treatment plan, the surgical movements are duplicated in the model surgery. During this procedure, reference points and lines are drawn on the base of the models over the dental arch, and sawcuts are made according to these marked osteotomy lines. This method requires more accuracy for better postsurgical results in that the surgical splint which enables the surgeon to position the jaws intraoperatively is made from the casts as repositioned by the model surgery, and finally it will define the postsurgical results. This technique, however, has been found to be inexact, especially when the jaws are moved in several dimensions simultaneously. To overcome this, different methods have been developed for an accurate repositioning of the jaws as planned. A new appliance, Surgical Jaw Relator, was devised by the author for the simple 3-dimensional relocation of the upper and lower models, resulting in the easy construction of the splints such as centric relation splint, intermediate and final splint. This article describes an introduction and a clinical application of this appliance.

Magnetic wireless motion capturing system and its application for jaw tracking system and 3D computer input device

  • Shin Yabukami;Kaoru Arai;Arai, Ken-Ichi;Shinya Tsuji
    • Proceedings of the Korean Magnestics Society Conference
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    • 2002.12a
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    • pp.12-12
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    • 2002
  • We present the new jaw tracking system that utilizes five degrees of freedom of head and lower jaw. The proposed method does not disturb the physiology because the system does not need to fix magnetic field sensors or clutch on the patient's body or mouth. The impact of this result goes beyond the conventional optical and magnetic tracking system of jaw movement [1][2]. Position accuracy within 1mm and reasonable cost is necessary for practical use of the jaw tracking system. (omitted)

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A Study on the Impact Load Quantification of the Jaw Crusher (쇄석기의 충격하중 정량화에 대한 연구)

  • Hong, Sung Ju;Yang, Hae Jeong
    • Journal of Drive and Control
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    • v.16 no.2
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    • pp.1-7
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    • 2019
  • Jaw crusher is a device that breaks rock collected from mines or quarries to produce aggregates of the size desired by user. A representative method for measuring load is to measure them by attaching force sensors directly to the part where the load is generated. However, the direct method has many limitations such as high-impact loads generation in equipment or space constraints, sensor capacities and costs. Therefore, Transfer Path Analysis (TPA) was used to indirectly measure impact loads by attaching acceleration sensors. In this study, both direct and TPA methods were used to measure the impact load of Jaw crusher. This study finally quantifies the impact of the load generated by the Jaw crusher using direct method and TPA method, and comparing the impact load measured calculated the derive the error rate.

Assessment of the increased calcification of the jaw bone with CT-Scan after dental implant placement

  • Yunus, Barunawaty
    • Imaging Science in Dentistry
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    • v.41 no.2
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    • pp.59-62
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    • 2011
  • Purpose : This study was performed to evaluate the changes of jaw bone density around the dental implant after placement using computed tomography scan (CT-Scan). Materials and Methods : This retrospective study consisted of 30 patients who had lost 1 posterior tooth in maxilla or mandible and installed dental implant. The patients took CT-Scan before and after implant placement. Hounsfield Unit (HU) was measured around the implants and evaluated the difference of HU before and after implant installation. Results : The mean HU of jaw bone was 542.436 HU and 764.9 HU before and after implant placement, respectively (p<0.05). The means HUs for male were 632.3 HU and 932.2 HU and those for female 478.2 HU and 645.5 HU before and after implant placement, respectively (p<0.05). Also, the jaw bone with lower density needed longer period for implant procedure and the increased change of HU of jaw bone was less in the cases which needed longer period for osseointegration. Conclusion : CT-Scan could be used to assess the change of bone density around dental implants. Bone density around dental implant was increased after placement. The increased rate of bone density could be determined by the quality of jaw bone before implant placement.

Jaw Tremors with Agitation : Two Cases Report (번조(煩躁)를 동반한 턱떨림 환자 2례에 대한 증례 보고)

  • Han, In Sik;Sun, Seung Ho;Oh, Hyun Suk;Lee, Deuk Soo;Lee, Yong Hyun;Jeong, Jong Jin;Lee, Won Chul
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.27 no.1
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    • pp.142-147
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    • 2013
  • The purpose of this study was to report the effect of Korean medicine and acupuncture in jaw tremor with Agitation. We studied two inpatients who had jaw tremor with agitation in the OO University Korean medicine hospital. They was treated with acupuncture (LU8, LR4, HT3, LR2) and herbal medicine. The effect of treatment was evaluated by Visual Analog Scale(VAS) and motor examination of Unified Parkinson's Disease Rating Scale(UPDRSIII). Both VAS of jaw tremor symptom and agitation and UPDRSIII score of tremor were decreased. The result suggest the combination treatment of herbal medicine and acupuncture might be effective for the jaw tremor with agitation.

A STUDY OF THE CHANGE OF MANDIBLE POSITION AND THE STABILITY AFTER ORTHOGNATHIC SURGERY (악교정 수술후 하악 근원심 골편의 위치 변화와 안정성에 관한 연구)

  • Nam, Kwang-Ho;Lee, Sang-Chull
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.29 no.2
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    • pp.95-101
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    • 2003
  • The purpose of this study was to evaluate the patterns of skeletal changes of proximal and distal segments after one jaw surgery and two jaw surgery with posterior impaction using SSRO on mandible in order to determine the skeletal origin of relapse and compare the stability of surgical methods in anterior open bite. The points and lines from lateral cephalometrics were measured before, after surgery, and at least 6-month follow up period. And then, the positional change of the proximal and distal segment were evaluated respectively. The results obtained were as follows; In cases of two jaw surgery, the results were stabler because they had less relapse factors. In cases of one jaw surgery, the value of APD were increased but it didn't relapse to the original value. Both of proximal and distal segments were responsible for the relapse tendency. But in one jaw surgery, the rotation of proximal segment was more responsible, and in two jaw surgery, the rotation of distal segment was.

Biochemical bone markers of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and nonbisphosphonate drugs in osteonecrosis of the jaw (임상가를 위한 특집 2 - Bisphosphonate-related osteonecrosis of the jaw(BRONJ)에 대한 biochemical bone markers와 악골괴사와 연관된 nonbisphosphonate drugs)

  • Lee, Deok-Won;Lee, Hyun-Woo;Kwon, Yong-Dae
    • The Journal of the Korean dental association
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    • v.52 no.4
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    • pp.203-217
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    • 2014
  • Bisphosphonates are widely used in the treatment of many medical conditions, such as osteoporosis, multiple myeloma, Paget's disease, etc. However, side effect has been documented in the published data during the past years, osteonecrosis of the jaw in patients receiving long-term bisphosphonate therapy. Although pathogenesis of BRONJ(bisphophonate-related osteonecrosis of the jaw) is not yet fully understood, it is currently known to be a disease associated with suppressed bone turnover by bisphopbonate. Recent literature has indicated a similar association with nonbisphosphonate drugs used in cancer therapy including monoclonal antibodies denosumab and bevacizumab and multikinase inhibitor sunitinib. Accordingly, many studies have been carried out on the biochemical markers examination to assess the risk for BRONJ. The treatment of BRONI is reported with a review of the relevant literature. However, there is still a controversial discussion about the adequate treatment. It is necessary to accumulate further studies in order to establish more useful biochemical markers and effective treatment for BRONJ.