• 제목/요약/키워드: open length

검색결과 1,013건 처리시간 0.025초

변환요소에 따른 LOOPED WIRE의 탄성 변화에 관한 연구 (A STUDY ON THE CHANGES OF THE ELASTIC PROPERTIES TN LOOPED WIRES BY VARIABLE FACTORS)

  • 나용인;김상철
    • 대한치과교정학회지
    • /
    • 제25권3호
    • /
    • pp.263-271
    • /
    • 1995
  • Canine retraction spring과 같은 looped wire에서, 각 변환요소에 따라 변하는 탄성 정도를 알아보기 위하여, wire의 재료, 굵기, loop에 소요된 길이, loop의 모양, gabling의 여부 등 5가지의 변환요소를 설정하여, 각 wire activation시의 탄성을 range, force, stiffness등의 면에서 알아보고자 하였다. wire의 재료적인 면에서 Hi-T (Unitek Co.)와 blue Elgiloy (Rocky Mountain Orthodontics)를 선택하였으며, 굵기로는 .016"$\;\times\;$.022" 와 .018"$\;\times\;$.025"를 선택하였다. loop 자체에 소요된 wire 길이를 15mm와 20mm의 두가지로, loop의 모양을 vertical open loop과 vertical closed loop의 두가지로, gabling의 양을 $0\circ$$30\circ$의 두가지로 하여 각각 제작하였다. 따라서 wire의 재료와 굵기, loop의 길이와 모양, gabling의 5가지 변환요소에 따라 32개군으로 구분되었으며, 각 군의 시료수는 8개씩으로, 총 256개의 시료를 대상으로 하였다. Instron(4202, Instron Co, USA)을 사용하여 각 시료의 하중변형 곡선을 얻었으며 elastic limit에서의 하중과 변형을 계측하고, 그때의 stiffness(force/range)를 산출하여, ANOVA 등의 통계처리로 32개군 간의 상관성을 조사하였다. 그 결과 wire의 재료, 굵기, loop의 길이, 모양, gabling모두가 looped wire의 하중 변형도에 유의한 영향을 미치는 것을 관찰할 수 있었으며, 탄성범위에서의 force는 Hi-T, .016"$\;\times\;$.022", loop 길이 20mm, open loop, non-gable군에서 가장 적었으며, blue Elgiloy, .018"$\;\times\;$.025", loop 길이 15mm, closed loop, non-gable군에서 가장 컸다. 탄성범위에서의 range는 Hi-T, .018"$\;\times\;$.025", loop길이 15mm, open loop, non-gable군이 가장 적었으며, Hi-T, .016"$\;\times\;$.022", loop길이 20mm, closed loop, gable군에서 가장 컸다. 또한 Looped wire의 탄성에 가장 큰 영향을 미치는 변환요소는 loop의 모양과 길이였으며, gabling의 영향이 가장 적었다.

  • PDF

풍력을 위한 소용량 EGD 발전기에 관한 기초적 연구 (Basic study on the EGD Generator of Small Capacity for the Wind Power)

  • 전춘생;박기남;임응춘
    • 태양에너지
    • /
    • 제12권3호
    • /
    • pp.126-136
    • /
    • 1992
  • In this paper an EGD generator of small capacity with the operating gases of $O_2,\;N_2$ and air is made and the electric characteristics in relation to energy conversion range length, corona current and gas pressure are investigated. The results are as follows: 1. There is a critical value in conversion range length for maximum open voltage and the critical value increases with fluid velocity. 2. The open voltage increases approximately linearly with corona current. 3. There is a critical value in the gas pressure for maximum open voltage and this pressure of gas decreases with fluid velocity in constant conversion range length.

  • PDF

고유전율 유전체를 이용한 CPW 급전 안테나의 설계 (Design of CPW fed antenna using high dielectric constant materials)

  • 심성훈;강종윤;윤석진;윤영중;김현재
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
    • /
    • pp.559-562
    • /
    • 2000
  • In this paper, coplanar waveguide fed antennas (CPWFAs) insetting two slits to boundary of the square microstrip patch are presented. These slits play roles in not only lowering a resonant frequency but also fine-tuning for the proposed antenna together with open stub of CPW feed line. The CPWFAs were designed and manufactured using microwave dielectrics (Al,Mg)TaO$_2$ having high dielectric-constant ($\varepsilon$r=20). The return loss and input impedance of the CPWFAs were investigated in terms of the slit length and open stub length of CPW feed line. It is shown that a resonant frequency decreases as the slit length increases.

  • PDF

원공을 가지는 복합재 적층판의 인장강도 예측 기법 (A Method to Predict the Open-Hole Tensile Strength of Composite Laminate)

  • 이흔주;신인수;정문규;권진회;최진호
    • Composites Research
    • /
    • 제24권4호
    • /
    • pp.29-35
    • /
    • 2011
  • 전통적인 특성길이 방법을 이용하여 원공이 있는 복합재 적층판의 강도를 예측하기 위해서는 원공이 있는 적층뿐만 아니라 원공이 없는 적층판에 대한 시험 결과와 유한요소해석이 필요하였다. 본 논문에서는 응력집중계수와 재료상수를 이용하여 유한요소해석 없이 복합재 적층판 원공 주위의 응력분포 및 인장특성길이를 추정하고, 이를 바탕으로 원공이 있는 복합재 적층판의 인장강도를 예측할 수 있는 방법을 제안하였다. 또한 새로운 방법에서는 재료의 효과가 변수로 고려되므로 다양한 재료에 대한 적용이 가능하며 원공이 있는 복합재 적층판에 대한 시험도 생략할 수 있다. 적층판 주위의 응력분포는 유한요소해석과의 비교를 통해 검증하였고, 최종적으로는 USN125 탄소/에폭시 적층판을 제작하여 파손하중 예측 결과와 시험 결과를 비교하였다. 원공이 있는 다양한 형상의 복합재 적층판의 파손강도 예측 결과는 최대 8% 이내의 오차로 시험 결과와 잘 일치함을 확인하였다.

뒤꿈치 인솔착용과 시각통제 유무가 하이힐 착용 시 균형관련 지수에 미치는 영향 (Influence of Heel Insole and Visual Control on Body Sway Index with High-heeled Shoes)

  • 윤정규
    • 대한물리의학회지
    • /
    • 제9권4호
    • /
    • pp.407-413
    • /
    • 2014
  • PURPOSE: We investigated the influence of heel insole and visual control on body sway index with high-heeled shoes. METHODS: The subjects of this study were 61 healthy students. None of the participants had any orthopedic or neurologic alterations. C90 area, C90 angle, trace length, sway average velocity were measured using a force plate by BT4. The variables were measured both with insole and without insole when wearing high-heeled shoes under the conditions of eyes open and eyes closed. The collected data were analyzed using the Kolmogorov-Smirnov test and paired t-test. RESULTS: When wearing high-heeled shoes with insole under the conditions of eyes open, trace length, C90 area, velocity were significantly more decreased than without insole (p<.01). When wearing high-heeled shoes with insole under the conditions of eyes closed, only C90 area was significantly more decreased than without insole (p<.05). When wearing high-heeled shoes with insole under the conditions of eyes open, trace length, C90 area, velocity were significantly more decreased than under the conditions of eyes closed (p<.01). CONCLUSION: The present study demonstrates that the use of high-heeled shoes with insole supported from heel to midfoot more increased static balance than without insole under the conditions of eyes open.

Electromagnetic Modeling of Quasi-Square Open Metallic Ring Frequency Selective Surface Using Wave Concept Iterative Procedure

  • Titaouine, Mohammed;Raveu, Nathalie;Neto, Alfredo Gomes;Baudrand, Henri
    • ETRI Journal
    • /
    • 제31권1호
    • /
    • pp.77-79
    • /
    • 2009
  • The wave concept iterative procedure (WCIP) is used to analyze a quasi-square open metallic ring frequency selective surface (FSS). The quasi-square open metallic ring FSS is dual-polarized. When the incident plane wave is polarized in a direction parallel to the FSS' coupled parallel strips, it shows two rejecting bands. Moreover, another rejecting band can be obtained if the source plane wave is perpendicularly polarized with respect to the FSS' coupled parallel strips. The three resonant frequencies are inversely proportional to the length of the FSS' coupled strips to provide an easy fine tuning of the FSS structure. The simulated results obtained using WCIP are compared to the measured results, and a good agreement is reported.

  • PDF

3D 그래픽 프로세서에서 효율적인 명령어를 위한 가변길이 명령어 설계 (Design of a Variable-Length Instruction for the Effective Usability Instruction in 3D Graphics Processor)

  • 김우영;이보행;이광엽;곽재창
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국해양정보통신학회 2008년도 춘계종합학술대회 A
    • /
    • pp.281-284
    • /
    • 2008
  • 최근 OpenGL ES 2.0이 개정됨에 따라 모바일 기기에 Shader 3.0모델을 지원 가능한 프로세서가 요구된다. 이 쉐이더 3.0 모델의 지원과 관련하여 명령어의 길이의 증가가 필요하고, 이는 메모리 용량의 증가를 초래한다. 본 논문에서는 가변길이 구조와 유닛구조를 채택한 새로운 명령어 구조를 제안한다. 이 명령어 구조는 쉐이더 3.0 모델을 지원하고 명령어 필드 낭비를 줄일 수 있도록 최대 4개의 32비트 유닛 명령어가 가변적으로 조합되어 수행된다.

  • PDF

복강경담낭절제술과 개복담낭절제술에 따른 진료량 비교 (A Comparison of Laparoscopic Cholecystectomy with Open Cholecystectomy in a Korean Hospital)

  • 이은미;유승흠;손명세;김석일
    • Journal of Preventive Medicine and Public Health
    • /
    • 제28권2호
    • /
    • pp.325-333
    • /
    • 1995
  • Laparoscopic cholecystectomy was introduced into Korea in 1990 and has been rapidly replacing open cholecystectomy when the indications were met. In this study a medical utilization and technology was assessed on the selected hospitalized patients with cholelithiasis who underwent open or laparoscopic cholecystectomy from April 1, 1991 to March 31, 1994. The results are as follows. Despite the low reimbursement rate by the health insurance, the number of laparoscopic cases have been steadily increased. The post-operative days before health insurance coverage were significantly shortened from 8.4 days to 4.6 days. The preoperative days before health insurance coverage were significantly shorted from 8.4 days to 4.0 days. The total length-of-stays in the hospital were also significantly shortened from 15.2 days to 10.7 and 9.8 days in laparoscopic cholecystectomy. The laparoscopic cholecystectomy showed low expenses in all aspects expect the average hospital charges per day. For the hospital to have cost containment, it is more effective if length-of-stay is shorter because of high daily inpatient hospital charge. The laparoscopic cholecystectomy also showed shortened anesthesia time and operation time compared with open cholecystectomy that were statistically significant. The mean anesthesia and operation time for open cholecystectomy were 113.2 and 90.2 minutes but those of laparoscopic cholecystectomy were 105.7 and 68.6 minutes. According to this study the laparoscopic cholecystectomy has reduced the medical expenditure and we recommend this procedure over open cholecystectomy. The further discussion on the different morbidity rate between two types of procedure is essential in providing quality medical care, and to educate specialist.

  • PDF

Open-jet boundary-layer processes for aerodynamic testing of low-rise buildings

  • Gol-Zaroudi, Hamzeh;Aly, Aly-Mousaad
    • Wind and Structures
    • /
    • 제25권3호
    • /
    • pp.233-259
    • /
    • 2017
  • Investigations on simulated near-surface atmospheric boundary layer (ABL) in an open-jet facility are carried out by conducting experimental tests on small-scale models of low-rise buildings. The objectives of the current study are: (1) to determine the optimal location of test buildings from the exit of the open-jet facility, and (2) to investigate the scale effect on the aerodynamic pressure characteristics. Based on the results, the newly built open-jet facility is well capable of producing mean wind speed and turbulence profiles representing open-terrain conditions. The results show that the proximity of the test model to the open-jet governs the length of the separation bubble as well as the peak roof pressures. However, test models placed at a horizontal distance of 2.5H (H is height of the wind field) from the exit of the open-jet, with a width that is half the width of the wind field and a length of 1H, have consistent mean and peak pressure coefficients when compared with available results from wind tunnel testing. In addition, testing models with as large as 16% blockage ratio is feasible within the open-jet facility. This reveals the importance of open-jet facilities as a robust tool to alleviate the scale restrictions involved in physical investigations of flow pattern around civil engineering structures. The results and findings of this study are useful for putting forward recommendations and guidelines for testing protocols at open-jet facilities, eventually helping the progress of enhanced standard provisions on the design of low-rise buildings for wind.

CONTROLLING TRAFFIC LIGHTS AT A BOTTLENECK: THE OBJECTIVE FUNCTION AND ITS PROPERTIES

  • Grycho, E.;Moeschlin, O.
    • 대한수학회지
    • /
    • 제35권3호
    • /
    • pp.727-740
    • /
    • 1998
  • Controlling traffic lights at a bottleneck, in [5] a time of open passage is called optimal, if it minimizes the first moment of the asymptotic distribution of the queue length. The discussion of the first moment as function of the time of open passage is based on an analysis of the behavior of a fixed point when varying control parameters and delivers theoretical and computational aspects of the traffic problem.

  • PDF