• 제목/요약/키워드: stability period

검색결과 1,550건 처리시간 0.025초

근거리 사진측량을 위한 스테레오 카메라의 안정성 분석 (Stability Analysis of a Stereo-Camera for Close-range Photogrammetry)

  • 김의명;최인하
    • 한국측량학회지
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    • 제39권3호
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    • pp.123-132
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    • 2021
  • 근거리 사진측량에서 스테레오 카메라를 이용하여 3차원 위치를 결정하기 위해 카메라의 내부표정요소뿐만 아니라 카메라 간의 상호표정요소를 결정하는 카메라 캘리브레이션이 선행되어야 한다. 카메라 캘리브레이션을 수행하고 나서 시간이 흐르면 비측량용 카메라의 경우 내부적인 불안정성이나 외부적인 요인에 의해 내부표정요소와 상호표정요소가 변할 수 있다. 본 연구에서는 스테레오 카메라 안정성을 평가하기 위해 두 대의 단일 카메라와 스테레오 카메라의 안정성을 분석뿐만 아니라 검사점을 이용하여 3차원 위치 정확도를 평가하였다. 4개월간 3회의 카메라 캘리브레이션을 수행한 실험을 통해 단일 카메라의 안정성을 평가한 결과 평균제곱근오차는 ±0.001mm로 나타났으며, 스테레오 카메라의 평균제곱근오차는 ±0.012mm ~ ±0.025mm로 나타났다. 또한, 검사점을 이용한 거리정확도를 평가한 결과 ±1mm로 나타나 다시기에 걸쳐 추정한 스테레오 카메라의 내부표정요소와 상호표정요소는 안정적인 것으로 판단되었다.

임프란트 표면 처리에 따른 공명주파수 변화에 대한 연구 (COMPARISON OF RESONANCE FREQUENCY ANALYSIS BETWEEN VARIOUS SURFACE PROPERTIES)

  • 배상범;이성현;송승일
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제32권2호
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    • pp.107-111
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    • 2010
  • Purpose: The aim of this study is to compare the stability between Mg-incorporated implant, TiUnite and Machined implant. Materials and Methods: Premolars of 3 Mini pigs (24 months) were extracted. After 2 months later, total 27 fixtures of implants (9 of each design : Machined/ TiUnite/ Mg-incorporated) were inserted into the mandible of 3 mini-pig. Implant stability was estimated by RFA in installation to 2, 4 & 6 weeks. Statistical analysis of RFA values was performed with time and between groups using repeated measure ANOVA and turkey's multiple comparison test. Results: In analyzing the mean value for the observation periods, three types of implants yielded a slight decrease in RFA mean value after 2 week, followed by increase at 4-6 weeks. Mg incorporated oxidized implants demonstrated significantly higher RFA mean values at 6 weeks comparing other groups. The difference of RFA value with time and between groups was statistically significant. Conclusion: We concluded that Mg implants may reduce failure rates of clinical implants In the early period of bone healing and Mg implants may shorten the bone healing time from surgery to functional loading.

간호단위 관리자의 가치지향성 리더쉽유형과 간호조직성과의 관계 (A study on the value orientation of nursing unit managers and nursing organization performances)

  • 한수정
    • 간호행정학회지
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    • 제9권2호
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    • pp.159-170
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    • 2003
  • Purpose : This study is to confirm the relation of the value orientation of the nursing unit manager and the job satisfaction and organizational commitment of the nursing unit nurse. Method : We used the systematic questionnaires as a study tool. The contents were composed of 46 questions in total such as 4 questions of general feature, 23 value-oriented questions, 10 job satisfaction questions, and 9 organizational commitment questions. The period of data collection was from August to September 2000. Result : 1) The value of flexibility was 3.82 points (${\pm}.3788$), which is above average. The values of equalitarianism was 3.37 points (${\pm}.4422$), which is above average. 2) The leadership pattern according to the value orientation perceived by the head nurses in 6 clusters has been divided into 3 patterns of change-oriented leader, task-oriented and stability-oriented leader. 3) The nurses who worked with the change-oriented leader showed higher values of job satisfaction (F=5.941, p=O.003), and affective commitment (F=5.793, p=O.003) than those who worked with the stability-oriented leader. Conclusion : As revealed in this study, we think that we have to consider that the change-oriented leader can produce higher performance of an organization than the stability-oriented leader, and write the basic data for the educational courses of leadership development or workshops etc. in order for the nursing unit managers to play their roles for the effective ward-unit management.

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태양광발전시스템의 안정성을 고려한 최적 각도 설정에 관한 연구 (A Study on the Optimal Angle Setting Considering the Stability of Photovoltaic Systems)

  • 이여진;한세경;김성열
    • 전기학회논문지
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    • 제67권4호
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    • pp.498-504
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    • 2018
  • The conventional photovoltaic(PV) systems are designed the installation angle for maximizing power output by considering a geographical characteristics, weather and climate conditions such as the solar radiation and atmosphere temperature. However, the PV generators must be designed to deal with the extreme situations like typhoons, earthquakes because PV systems are exposed to the ambient conditions and external shock due to condition of PV location. Especially, the wind has relatively higher influence on the design of PV systems, in this paper we proposed the method of determining the optimal nominal dimension of the facilities, which can withstand the maximum wind pressure. By using the proposed method, we determined the optimal installation angle for the aspect stability of PV facilities and amount of power output. Moreover, we analyzed the monthly amount of power for each installation angle of PV systems, and proposed the changing strategy of installation angle by determining the optimal angle to produce maximum power for each period.

하악 전돌자의 하악지 시상분할 골절단술 후의 안정성에 대한 평가 (Evaluation of Post-Treatment Outcome of Sagittal Split Ramus Osteotomy in Mandibular Prognathism Patients)

  • 정동화
    • 구강회복응용과학지
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    • 제22권4호
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    • pp.271-281
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    • 2006
  • Long term prediction of surgical result of skeletal class III has not been evaluated adequately because the stability of orthognathic surgery would be affected by not only set back amount of mandible but also many other factors like skeletal pattern, hyoid position, and airway size. The aimof this study is to discriminate the factors which affect the stability of post-treatment result of surgical outcome of sagittal split ramus osteotomy. We have collected 37 patients (male: 17, female: 20) from patients who have been treated at Orthodontic Department in Dankook University. The patients underwent 3 times Cephalometric X-ray taking at pre-, post-orthognathic surgery and after 12 months retention. The subjects were divided into 2 groups (Stable group: 21, Relapse group: 16) according to their relapse amount. We have taken following results from Students t-test and discriminant analysis. The discriminant factors which discern relapse and stable groupe among treatment change variables were BX and Ba-HY. Hyoid bone moved to posterior and inferior position due to surgery and repositioned superiorly and posteriorly during retention period. Skeletal patterns of the relapse group are smaller mandibular plane angle, anterior mandibular position, and greater distance from hyoid bone to cervical bone and mandible respectively.

강우침투시 불포화 무한사면의 안정성 평가 (Stability of unsaturated infinite slope under rainfall-induced infiltration)

  • 송영석;황웅기;이남우;김태형
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회
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    • pp.71-78
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    • 2010
  • The stability analysis of unsaturated infinite slope under rainfall-induced infiltration condition was performed using the generalized effective stress that unifies both saturated and unsaturated condition recently proposed by Lu and Likos(2004, 2006). The Soil-Water Characteristic Curve (SWCC) of the sand with the relative density of 75% was first measured for both drying and wetting processes. The Hydraulic Conductivity Function (HCF) and Suction Stress Characteristic Curve (SSCC) were subsequently estimated. Also, under the rainfall-induced infiltration condition transient seepage analysis of unsaturated infinite slope was performed using the finite element program, SEEP/W. Based on these results, the stability of unsaturated infinite slope under rainfall-induced infiltration condition was examined considering the suction stress. According to the results, the negative pore water pressure and water content within the soil changed with time due to the infiltration. Also, the variation of those caused the variation of suction stress and then the factor of safety of slope changed consequently during the rainfall period.

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Effect of Various Phyto-extracts on Physico-chemical, Colour, and Oxidative Stability of Pork Frankfurters

  • Wagh, Rajesh V.;Chatli, Manish K.;Ruusunen, Marita;Puolanne, Eero;Ertbjerg, Per
    • Asian-Australasian Journal of Animal Sciences
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    • 제28권8호
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    • pp.1178-1186
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    • 2015
  • Lipid oxidation, colour stability and physico-chemical quality of pork frankfurters with the incorporation of 0.30% sea buckthorn (SBT), 0.10% grape seed (GSE), 0.03% green tea (GTE), 0.12% fenugreek seed (FSE) and 0.10% Acacia catechu (ACE) were studied during 20 days of refrigerated aerobic storage. The SBT and ACE were identified as being the most effective antioxidants to retard lipid oxidation with the potency decreasing in the following order: SBT>ACE>GSE>GTE>FSE based on thiobarbituric acid reacting substances, peroxide value and free fatty acids. In all samples pH and $a_w$ decreased during storage period. The $L^*$ value of treated as well as control samples decreased over time while SBT and ACE exhibited an increased redness producing higher $a^*$ values than other treatments. However, GTE was more effective in increasing $b^*$ values than other treatments at the end of storage. The results suggest that functional plant-derived extracts can be valuable to the modification of frankfurter formulations for improved oxidative stability as well as quality characteristics.

An Orbital Stability Study of the Proposed Companions of SW Lyncis

  • Hinse, T.C.;Horner, Jonathan;Wittenmyer, Robert A.
    • Journal of Astronomy and Space Sciences
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    • 제31권3호
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    • pp.187-197
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    • 2014
  • We have investigated the dynamical stability of the proposed companions orbiting the Algol type short-period eclipsing binary SW Lyncis (Kim et al. 2010). The two candidate companions are of stellar to substellar nature, and were inferred from timing measurements of the system's primary and secondary eclipses. We applied well-tested numerical techniques to accurately integrate the orbits of the two companions and to test for chaotic dynamical behavior. We carried out the stability analysis within a systematic parameter survey varying both the geometries and orientation of the orbits of the companions, as well as their masses. In all our numerical integrations we found that the proposed SW Lyn multi-body system is highly unstable on time-scales on the order of 1000 years. Our results cast doubt on the interpretation that the timing variations are caused by two companions. This work demonstrates that a straightforward dynamical analysis can help to test whether a best-fit companion-based model is a physically viable explanation for measured eclipse timing variations. We conclude that dynamical considerations reveal that the proposed SW Lyncis multi-body system most likely does not exist or the companions have significantly different orbital properties from those conjectured in Kim et al. (2010).

플루란 아세테이트 미립구를 이용한 단백질 전달 시스템 개발 (Development of Protein Delivery System using Pullulan Acetate Microspheres (PAM))

  • 나건;최후균
    • Journal of Pharmaceutical Investigation
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    • 제36권2호
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    • pp.115-121
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    • 2006
  • The aim of this study was to develop new protein/peptide depot system instead of poly(DL-lactic acid-coglycolic acid) (PLGA) microspheres. Pullulan was chemically modified by the addition of acetic anhydride (pullulan acetate; PA) and then investigated as new depot system for protein/peptide delivery. PA microspheres (PAM) with lysozyme as a model protein were prepared by w/o/w double emulsion method. The microspheres had a mean size of 10-50 mm with a spherical shape. The size distributions reduced with increasing the degree of acetylation. The loading efficiency of lysozyme was also increased. Lysozyme aggregation behavior in the microsphere was monitored to estimate the change of protein stability during preparation step. The ratios of protein aggregation in PAMs are lower than that of PLGA microsphere, in particular, PA 5 showed lowest as about 16%. The result indicated that the increase of acetylation suppressed the aggregation of protein. The release profiles of lysozyme from PAMs were significantly different. High acetylation effectively improved lysozyme release kinetics by reducing initial burst release and extending continuous release over a period of time. To check the effect of preservation for structural stability of lysozyme, the activity of lysozyme released from PA 5 was also observed. The activity of lysozyme was maintained almost 100% for 25 day. Therefore, PAM may become to a useful carrier for delivery of protein/peptide drugs, if it will be supported by biocompatibility and biodegradability results.

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

  • 남광호;이상철
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제29권2호
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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.