• 제목/요약/키워드: Tightness

검색결과 438건 처리시간 0.024초

응결시간차를 활용한 매스콘크리트의 수화열 조정에 관한 기초적 연구 (A Fundamental Study on the Control of Hydration Heat of Mass Concrete Using Setting Time Difference)

  • 배정렬;윤치환;김기철;한민철;오선교;한천구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2002년도 학술논문발표회
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    • pp.41-45
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    • 2002
  • Placing lift is applied to place mass concrete in order to reduce thermal cracks by hydration heat. But they results in cold joint between placing lifts, which bring about the loss of strength, water tightness and undesirable appearance. Therefore, in this paper, mechanical and hydration heat of mass concrete using super retarding agent developed through previous study are investigated in order to reduce the hydration heat and place it without place lift. According to test results, placing lifts combined with normal concrete and concrete containing super retarding agent have positive effects on reducing hydration heat. Especially, the crack index by thermal stress of the concrete containing super retarding agent less than a quarter, compared to that of plain concrete without placing lifts, and less than a half, compared to that of plain concrete with placing lifts.

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폐석회석의 분말도 변화에 따른 콘크리트의 특성분석 (An Analysis on Concrete Properties with the Fineness of Waste Limestone)

  • 류현기;우종권
    • 한국건축시공학회지
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    • 제7권1호
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    • pp.85-90
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    • 2007
  • According as industry develops rapidly, problem of resources exhaustion and environmental pollution is appearing. Way to use construction waste that is development of new compound material and Industry product is required. Limestone powder that is Industry product is $CaCO_3$. and vicosity is promotion effect because there is no damage to hydration of cement and powder is very thin and water tightness increases. This research purposed to analyze concrete property changing limestone fineness. According as the limestone powdered replacement ratio increases, slump and unit capacity mass increased, and the air content decreased according as the replacement ratio increases. Compressive strength and tensile strength decreased according as the limestone powder replacement ratio increases.

On a functional central limit theorem for the multivariate linear process generated by positively dependent random vectors

  • 김태성;백종일
    • 한국통계학회:학술대회논문집
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    • 한국통계학회 2000년도 추계학술발표회 논문집
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    • pp.119-121
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    • 2000
  • A functional central limit theorem is obtained for a stationary multivariate linear process of the form $X_t=\sum\limits_{u=0}^\infty{A}_{u}Z_{t-u}$, where {$Z_t$} is a sequence of strictly stationary m-dimensional linearly positive quadrant dependent random vectors with $E Z_t = 0$ and $E{\parallel}Z_t{\parallel}^2 <{\infty}$ and {$A_u$} is a sequence of coefficient matrices with $\sum\limits_{u=0}^\infty{\parallel}A_u{\parallel}<{\infty}$ and $\sum\limits_{u=0}^\infty{A}_u{\neq}0_{m{\times}m}$. AMS 2000 subject classifications : 60F17, 60G10.

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개심술후에 발생한 지연성 심장압진증 (Deleyed Cardiac Tamponade After Open Heart Surgery (Two Cases Report))

  • 김병열
    • Journal of Chest Surgery
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    • 제15권2호
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    • pp.218-221
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    • 1982
  • Delayed cardiac tamponade in an uncommon and frequently fatal complication after open-heart surgery. We had been experienced two cases of delayed cardiac tamponade as a complication of open-heart surgery and treated successfully by reinsertion of pericardial drain through subxiphoid route. First case was 60 years old female patient and underwent MVR under impression of MSi + Ti Second case was 19 years old male patient and underwent total correction of T.O.F.with Blalock shunt [Lt]. Both cases had Initial symptoms, which were epigastric pain, chest tightness, dropped blood pressure, and increased pulse rate and respiratory rate, mimic as low cardiac output syndrome after open-heart surgery. Roentgenogram of the chest showed a rapid increased cardiothoracic ratio. It is important to realize the presence of late cardiac tamponade for proper diagnosis of complication after open-heart surgery.

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고압 상황에서 작동되는 극저온 기액 분리기와 액체 계면 측정기의 개발 (Development of cryogenic liquid-vapor separator and liquid-level meter operating under high pressure condition)

  • 이천규;황규완;정상권
    • 한국초전도ㆍ저온공학회논문지
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    • 제13권1호
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    • pp.51-55
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    • 2011
  • In this study, the liquid-vapor (L-V) separator equipped with liquid-level meter is developed. In the developed L-V separator, the flange is designed to be attachable so that the separator can be flexibly applied under any cases where the volumetric of L-V separator is varied by the system requirement. The leak-tightness between the attachable flange and the chamber is experimentally confirmed with the use of double groove indium wire sealing even under the high pressure up to 20 bar. In addition, the liquid-level meter is designed and fabricated to figure out the inner state of L-V separator. It consists with 19 carbon composition resistors in series. All resistors are separately calibrated in the temperature range from 77 K to 200 K. The performance of the L-V separator and the liquid-level meter is investigated with experimental tests, and the result is presented in this paper.

퍼멀로이 실딩캔의 강성증대 및 형상 정밀도를 위한 최적 헤밍 공정설계 (Hemming Process Design of the Permalloy Shielding Can for the Stiffness and Shape Accuracy)

  • 이선봉;김동환;김병민
    • 한국정밀공학회지
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    • 제19권5호
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    • pp.29-35
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    • 2002
  • This study shows the process design and forming analysis of permalloy shielding can that support the automobile multi-display parts to indicate the accurate information of car. This study is particularly important, since the accuracy of permalloy shielding can is known to affect the magnetic properties such as coercivity and permeability quite sensitively. The objective functions are defects such as hemming wind, hemming length, hemming wrap and tightness in prehemming process. The pre-hemming angle is considered as design parameter. The commercial finite element program PAM-STAMP™ was used to simulate the pre-hemming and hemming process. The ANN (Artificial Neural Network) has been implemented for minimizing of objective function and for investigating effect of punch angle relevant to the pre-hemming process. The results of analysis to validate the proposed design method are presented.

20대 여성의 브래지어 치수설정과 의복압에 관한 연구 (A Study on Establishment of Brassiere Size and Clothing Pressure for the Twenties-aged Women)

  • 박유신;임영자
    • 복식
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    • 제52권8호
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    • pp.15-27
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    • 2002
  • To set the measurements of bras for women in their 20s, considering the comfortableness in wearing and tightness, this paper conducted a questionnaire survey concerning breasts and bras as well as measurements of body and contact surface pressure. Easier and more accurate method of determining cup sizes based on the breast circumference is recommended to make up for the problem of current bra size system that can falsely measure cup sizes. Lower chest circumference was set at 5 cm equal intervals, and the breast circumference applicable to the cup size was set starting from the standard, 18 cm (A-cup), at 2 cm equal intervals, which gave the best coverage (88.1%).

Diagnosis of Iliotibial Band Friction Syndrome and Ultrasound Guided Steroid Injection

  • Hong, Ji Hee;Kim, Ji Sub
    • The Korean Journal of Pain
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    • 제26권4호
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    • pp.387-391
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    • 2013
  • A 64-year-old woman visited our pain clinic with the pain of right lateral side of thigh for one year. Her pain always started from knee and was radiated to buttock area when symptom was severe. She showed significant tenderness at knee lateral side and local tightness at lateral thigh. Magnetic resonance image of the knee was performed and we could identify high signal intensity of iliotibial band through coronal and axial view. In spite of medication and physical stretching exercise of iliotibial band for one month, she did not show any improvement of pain. To alleviate her symptom, ultrasound guided local corticosteroid injection targeting beneath the iliotibial band was performed. After the procedure, the reduction of pain was significant and there was no need for further management.

경막외강내 우발적 Vancomycin 투여에 의한 임상경과 1예 (Inadvertent Epidural Injection of Vancomycin -A case report-)

  • 김명옥;윤덕미;오흥근
    • The Korean Journal of Pain
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    • 제5권1호
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    • pp.121-125
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    • 1992
  • A 37-year-old male was admitted for left chest pain during a 6 months period and was given an epidural block for pain control. Vancomycin 500 mg/4 ml instead of 0.25% bupivacaine was accidentaly injected into the epidural space. The patient suddenly complained of an unexpected chest tightness and dyspnea after epidural injection. The patient was treated with steroids and local anesthetics via epidural space and recovered without any neurologic sequelae. The patient completely recovered on the 46th postadmission day and went home without any complaints. We report this case and review the accidental injection of substances into the epidural space.

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납기를 갖는 job shop 일정계획의 효율적인 발견적기법 (An Efficient Heuristic Technique for Job Shop Scheduling with Due Dates)

  • 배상윤;김여근
    • 한국경영과학회지
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    • 제21권3호
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    • pp.75-88
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    • 1996
  • This paper presents an efficient heuristic technique for minimizing the objectives related to tardiness such as total tardiness, maximum tardiness and root mean of tardiness in the job shop scheduling. The heuristic technique iteratively improves an active schedule through exploring the schedule's neighborrhood, using operation move methods. The move operatio is defined on an active chain of tardy jobs in the active schedule. To find the move operations which have a high probability of reducing tardiness, we develop move methods by exploiting the properties of active chains. Our technique is compared with the two existing heuristic techniques, that is, MEHA(Modified Exchange Heuristic Algorithm) and GSP(Global Scheduling Procedure) under the various environmental with the three levels of due date tightness and several sized problems. The experimental results show that the proposed technique outperforms the two exissting techiques in terms of solution quality and computation time.

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