• Title/Summary/Keyword: safety joint

검색결과 818건 처리시간 0.029초

가중함수법에 의한 기계적 체결부에 존재하는 타원형 모서리균열의 혼합모드 응력확대계수 (Mixed-Mode Stress intensity Factors for Elliptical Corner Cracks in Mechanical Joints by Weight Function Method)

  • 허성필;양원호;김철
    • 대한기계학회논문집A
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    • 제25권4호
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    • pp.703-713
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    • 2001
  • Mechanical joints such as bolted or riveted joints are widely used in structural components and the reliable determination of the stress intensity factors for corner cracks in mechanical joints is needed to evaluate the safety and fatigue life. This paper analyzes the mixed-mode stress intensity factors of surface and deepest points for quarter elliptical corner cracks in mechanical joints by weight function method and the coefficients included in weight function are determined by finite element analyses for reference loadings. The extended form of the weight function method for two-dimensional mixed-mode to three-dimensional is presented and the number of terms in weight function is determined by comparing the results for the different number of terms. The amount of clearance is an important factor in evaluating the severity of elliptical corner cracks in mechanical joints and even horizontal crack normal to the applied load is under mixed-mode in the case that clearance exists.

Botulinum Toxin : 기초과학과 이비인후과 영역에서의 임상적 사용 (Botulinum Toxin : Basic Science and Clincal Uses in Otolaryngology)

  • 최홍식;문인석;김한수;김현직
    • 대한후두음성언어의학회지
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    • 제13권2호
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    • pp.164-172
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    • 2002
  • The role of botulinum toxin as a therapeutic agent is expanding rapidly in otolaryngology. Botulinum toxin is a protease that blocks the release of acetylcholine from nerve terminals. Its effects are transient and nondestructive, and largely limited to the area in which it is administered These effects are also graded according to the dose, allowing for individualized treatment of patients and disorders. Botulinum toxin has been used primarily to treat disorders of excessive or inappropriate muscle contraction. In the field of otolaryngology, these include spasmodic dysphonia, oromandibular dystonia, and blepharospasm, vocal tics and stuttering, cricopharyngeal achalasia, various tremors and tics, hemifacial spasm, temporomandibular joint disorders and a number of cosmetic applications. Botulinum toxin treatment has recently begun to show some benefit in the control of pain from migraine and tension headache. It may also prove useful in the control of autonomic dysfunction, as in Frey syndrome, sialorrhea, and rhinorrhea. In over 20 yews of use in humans, botulinum toxin has accumulated a considerable safety record, and in many cases represents relief for thousands of patients unaided by other therapy.

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실물실험을 통한 PC-Slab합성 판형교의 성능비교연구 (A Study on the Comparison of Performance of PC-Slab Composite Plate Girder from the Actual Sized Experiment)

  • 민경주;이성욱;김영국;우용근
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.1300-1309
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    • 2010
  • In the railway bridges, steel plate girder types are preferred due the high stability. Nevertheless, it has been pointed out that this type of bridge has problems such as, structural damages in the rail and girder seat, noise problem due to impact at the rail joint and excessive vibration. This vibration and/or deflection are mainly because insufficient stiffness of steel plate type of bridge. To resolve these problems, PC-Slab composite plate girder type which has simple process and economic cost, is proposed in this study. The static and dynamic experiment is performed by using the production of actual sized PC-Slab and abandoned steel plate girder. The object of this experiment is to verify the fact that girder stiffness increase and structural safety. The result of the experiment is used to analyze the effect of performance improvement of PC composite plate girder type. Using this method, economic rail maintainers, girder stiffness increase, and also speed/ride improvement even for existing rail could be expected by dynamic performance improvement. Additionally noise due to impact, deflection and vibration caused from long rails can be reduced.

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교량상 slab궤도의 상향력 민감도분석 (Parameteric Analysis for Up-lifting force on Slab track of Bridge)

  • 최성기;박대근;한상윤;강영종
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.1188-1195
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    • 2007
  • The vertical forces in rail fasteners at areas of bridge transitions near the embankment and on the pier will occur due to different deformations of adjoining bridges caused by the trainloads, the settlement of supports, and the temperature gradients. The up-lifting forces is not large problem in the blast track because the elasticity of blast and rail pad buffs up-lifting effect. But, it is likely to be difficult to ensure the serviceability of the railway and the safety of the fastener in the end in that concrete slab track consist of rail, fastener, and track in a single body, delivering directly the up-lifting force to the fastener if the deck is bended because of various load cases, such as the end rotation of the overhang due to the vertical load, the bending of pier due to acceleration/braking force and temperature deviation, the settlement of embankment and pier, the temperature deviation of up-down deck and front-back pier, and the rail deformation due to wheel loads. The analysis of the rail fastener is made to verify the superposed tension forces in the rail fastener due to various load cases, temperature gradients and settlement of supports. The potential critical fasteners with the highest uplift forces are the fastener adjacent to the civil joint. The main influence factors are the geometry of the bridge such as, the beneath length of overhang, relative position of bridge bearing and fastener, deflection of bridge and the vertical spring stiffness of the fastener.

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초고층 건축물의 위생설비 시스템 설계 (Sanitary Plumbing System Design of High-rise Building)

  • 주덕훈;변운섭;윤해동
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.491-496
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    • 2009
  • Recently, the high-rise building has been constructed competitively because it is symbol of the national competitive power including the technical power. The higher buildings are getting, the more important building mechanical systems are. So, the building mechanical systems are getting developed. Among the building mechanical systems, the sanitary system is basically necessary in order to maintain the building hygienically along with convenience and safety. This study has been investigated for various cases of high-rise building plumbing system. As a result, a variety of zoning method has been applied to most skyscrapers depending on the building height in the building mechanical system. And a variety of joint have been applied to minimize the Shortening and Sway. Also, the drainage in same uses has been discharged outside of a build through the one vertical pipe line. And airing system has been used like Individual Vent Pipe Yoke Vent Pipe Stack Vent Pipe Loop Vent Pipe Relief Vent Pipe method. It is sure that this study could be used as the high-rise building design.

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보건의료 빅데이터를 활용한 연구방법 및 한의학 레지스트리의 필요성 (Application of Health Care Big data and Necessity of Traditional Korean Medicine Data Registry)

  • 한경선;하인혁;이준환
    • 한방비만학회지
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    • 제17권1호
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    • pp.46-53
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    • 2017
  • Health care big data is thought to be a promising field of interest for disease prediction, providing the basis of medical treatment and comparing effectiveness of different treatments. Korean government has begun an effort on releasing public health big data to improve the quality and safety of medical care and to provide information to health care professionals. By studying population based big data, interesting outcomes are expected in many aspects. To initiate research using health care big data, it is crucial to understand the characteristics of the data. In this review, we analyzed cases from inside and outside the country using clinical data registry. Based on successful cases, we suggest research method for evidence-based Korean medicine. This will provide better understanding about health care big data and necessity of Korean medicine data registry network.

Systemic use of fluoroquinolone in children

  • Choi, Soo-Han;Kim, Eun Young;Kim, Yae-Jean
    • Clinical and Experimental Pediatrics
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    • 제56권5호
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    • pp.196-201
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    • 2013
  • Fluoroquinolones are an important class of antibiotics that are widely used in adult patients because of their broad spectrum of activity, good tissue penetration, and oral bioavailability. However, fluoroquinolone use in children is limited because juvenile animals developed arthropathy in previous experiments on fluoroquinolone use. Indications for fluoroquinolone use in patients younger than 18 years, as stated by the U.S. Food and Drug Administration, include treatment of complicated urinary tract infections and postexposure treatment for inhalation anthrax. In Korea, the systemic use of fluoroquinolones has not been approved in children younger than 18 years. Although concerns remain regarding the adverse musculoskeletal effects of fluoroquinolones in children, their use in the pediatric population has increased in many circumstances. While pediatricians should be aware of the indications and adverse effects of fluoroquinolones, recent studies have shown that the risk for musculoskeletal complications in children did not significantly increase following fluoroquinolone treatment. In addition, fluoroquinolones may be particularly helpful in treating multidrug-resistant infections that have not responded to standard antibiotic therapy in immunocompromised patients. In the present article, we provide an updated review on the safety and current recommendations for using fluoroquinolones in children.

한냉물리치료기의 개발 (Development of the Cryotherapy System)

  • 김영호;양길태;임송학;장윤희;유진상;김종성;박시복;백승석;정우성
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.388-391
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    • 1997
  • A cryotherapy system using the low temperature air was developed. The developed cryotherapy system had superior low temperature characteristics and many safety devices. For a clinical evaluation, skin and intra-articular temperatures of the knee joint were measured during and after the cryotherapy. After 5-minute therapy, skin and intra-articular temperature decreased by $23.3{\pm}4.7(^{\circ}C)$ and $4.1{\pm}1.0(^{\circ}C)$ respectively. A 5-minute cryotherapy therapy is good enough to maintain low intra-articular temperatures or 2-3 hours.

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콘크리트 표면차수벽형 석괴댐 지지층의 토질특성 (Soil Properties of Bedding Bone for Concrete Faced Rockfill Dam)

  • 배종순;성영두
    • 한국지반공학회지:지반
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    • 제12권1호
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    • pp.47-62
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    • 1996
  • The bedding zone which influence directly to the safety of dam is supporting the face slab under hydraulic load in concrete faced rockfill dam. In case that leakage is developed due to various ruptured joint or cracks of face slab and etc., the bedding zone should limit the leakage by low permeability and keep the internal stability. In this study for the proper coefficient of permeability various properties, such as gradation, dry density, performance of embankment work and etc. were analysed. The results from the large scale test of permeability and density are summerized as follows : 1. Coefficient of permeability is decreased clearly by increase of dry density. 2. The particles smaller than the No.4 strive( p,) greatly influences the permeability under dry density of 2.24t 1 m3. 3. In case of C.40 and p,40%, even if dry density decreased to 2.0t/m3, the permeability coefficient is assumed to u x1-scm/s and internal stability is abtained. 4. Generally in dam construction since dry density and uniformity coefficient of bedding zone were higher than 2.2t/m3 and 50 respectively p, of 30~40% is assumed to be suitable and permeability coefficient of below 1$\times$10-3cm l s is expectable.

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이중선각구조 선박의 최종굽힘강도와 피로강도에 대한 안전성 평가 (Safety Assessment of Double Skin Hull Structure against Ultimate Bending and Fatigue Strength)

  • 양박달치;이주성
    • 대한조선학회논문집
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    • 제29권1호
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    • pp.93-102
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    • 1992
  • 본 논문에서는 종굽힘하에서 이중선각구조선박의 최종굽힘강도와 피로강도에 대한 신뢰성평가를 다루었다. 최종굽힘강도는 beam-column approach의 개념을 이용하여 구하였고, 보강판의 응력-변형도 곡선들은 소성힌지의 개념을 이용하여 유도하였다. 피로강도는 피로손상에 대한 것만을 고려하였고, 이를 위해 Miner의 손상식을 이용하였다. 갑판에서 가능한 여러 연결부 형태에 대해 그 피뢰신뢰성을 추정하였고 또한 굽힘에 의한 파괴와 피로에 의한 파괴를 동시에 고혀하는 일종의 Series System에 대한 신뢰성을 평가를 하였다.

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