• 제목/요약/키워드: Section Change

검색결과 1,400건 처리시간 0.026초

표준전동차 차내소음특성 예측 연구 (Study on the Prediction of Inner Noise Characteristics in Standardization EMU)

  • 박준서;한기흥;김정태
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2000년도 추계학술대회 논문집
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    • pp.133-141
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    • 2000
  • Standardization EMU in comparison with the existing EMU has been largely changed the material and section profile of the structure as the Aluminium made. This study is analytically predicted the influence of inner noise in tunnel running when the above change is made.

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모델예측제어 기법을 이용한 제지공정에서의 지종교체 제어 (Control of Grade Change Operations in Paper Plants Using Model Predictive Control Method)

  • 김도훈;여영구;박시한;강홍
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2003년도 추계학술발표논문집
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    • pp.230-248
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    • 2003
  • 본 연구에서는 제지공정에서의 wet-end 와 dry section 부분을 통합한 모델을 구하고 이를 바탕으로 하여 지종교체 공정의 모델예측제어 방법을 제안하였다. 폐회로 공정 인식기법을 이용하여 state-space 모델을 구한 후 지종교체 제어를 모사한 결과와 실제 제지공장의 지종교체 운전데이터를 비교 분석하였다. 입력 변수로서 이전까지는 간과되어 왔던 4가지 변수(thick stock, filler flow, speed, steam pressure), 그리고 출력변수로서 3가지 변수(basis weight, ash content, moisture content)를 고려하였으며, output trajectory는 1차 전달함수 형식으로 하여 적용하였다. 모델예측제어 모사결과를 지종교체 운전데이터와 비교하여 본 결과 지종교체 시간이 짧아지고 보다 안정적으로 정상상태에 이르는 것을 확인할 수 있었다. 아울러 모델예측제어로 인하여 지종교체 이후 입력 변수들이 큰 진동이 없이 보다 신속하게 정상상태에 도달함을 확인하였다.

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2006년과 2007년 여름에 관측한 Hawaii-Chuuk 사이의 물리특성 (Physical Oceanographic Characteristics between Hawaii and Chuuk Observed in Summer of 2006 and 2007)

  • 신창웅;김동국;전동철;김응
    • Ocean and Polar Research
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    • 제33권spc3호
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    • pp.371-383
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    • 2011
  • To investigate the physical characteristics and variations of oceanic parameters in the tropical central North Pacific, oceanographic surveys were carried out in summer of 2006 and 2007. The survey periods were classified by Oceanic Ni$\tilde{n}$o Index as a weak El Ni$\tilde{n}$o in 2006 and a medium La Ni$\tilde{n}$a in 2007. The survey instruments were used to acquire data on CTD (Conductivity Temperature and Depth), XBT (Expendable Bathythermograph), and TSG (Thermosalinograph). The dominant temporal variation of surface temperature was diurnal. The diurnal variation in 2007, when the La Ni$\tilde{n}$a weather pattern was in place, was stronger than that in 2006. Surface salinity in 2006 was affected by a northwestward branch of North Equatorial Current, which implies that the El Ni$\tilde{n}$o affects surface properties in the North Equatorial Current region. Two salinity minimum layers existed at stations east of Chuuk in both year's observations. The climatological vertical salinity section along $180^{\circ}E$ shows that the two salinity minimum layers exist in $2^{\circ}N{\sim}12^{\circ}N$ region, consistent with our observations. Analysis of isopycnal lines over the salinity section implies that the upper salinity minimum layer is from intrusion of the upper part of North Pacific Intermediate Water into the lower part of South Pacific Subtropical Surface Water and the lower salinity minimum layer is from Antarctic Intermediate Water.

레일 경좌 변화에 따른 곡선부 통과열차의 주행안전성 해석 (Running Safety Analysis of Railway Vehicle passing through Curve depending on Rail Inclination Change)

  • 김문기;엄범규;이희성
    • 한국소음진동공학회논문집
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    • 제23권3호
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    • pp.199-208
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    • 2013
  • So far today, there is a speed limit by the radius of curve based on operation regulation in domestic railway, however a study for the maximum running speed at the curved section without any derailment would be necessary. The two major factors related to the running safety of railway vehicle are classified as the railway vehicle condition and the track condition. In terms of the rail inclination among many other factors, the determination of rail inclination within the possible limit is necessary for the geometrical structure of the optimum track. The disregard of the geometrical parameter related to the rail inclination may cause a serious problem to the running safety of railway vehicle. This study is focusing on the analyzing of running safety regard to the change of rail inclination among the many other parameters to improve derailment safety, so that there is an affection analysis of the running safety regard to the change of rail inclination in the ideal and geometric track condition. Also There is an affection analysis of the running safety regard to the simultaneous change of rail inclination and the running speed at the curved section. According to analysis results of running safety, In case that the left and right rail inclination are 1/40, the running safety of this condition defined than other conditions. Also, the rail inclination of conventional lines is 1/40, Therefore, the railway vehicle passing through curve is safe when the railway vehicle runs in conventional lines.

연령증가에 따른 정상 한국인 대퇴골의 재형성에 관한 연구 (A Study on the Age-related Remodeling of Femur in Normal Korean Adult)

  • 강승백;배태수;최재봉;최귀원
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.489-492
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    • 1997
  • The general pattern of adaptation in the appendicular skeleton with aging is that the subperiosteal apposition of bone occur along with endosteal absorption. This remodeling of diaphysis to a cylinder of larger diameter is hypothesized to serve a mechanical compensatory unction by increasing the moment of inertia as the cortex thins with aging. These findings is only true of the diaphysis of long bone. Measuring the area and inertia at each section of femur, the age-related change of proximal emur and diaphysis is observed. After screening by physical and radiological examination, 200 normal Korean adults divided 5 groups in both male and female based on age. Twenty persons were in each group. One femur in each person was analyzed using CT images. femur scanned with 60 to 80 slices and this images were digitized. Then 2-D images were reconstructed into 3-D images. Using the nonlinear method, normalization and interpolation technique, 7 locations of interest (trochanteric area: 1, 2 subtrochanteric area: 3, 4, isthmic area: 5, 6, 7) were determined. On the each cross section at each location, the area (total, cortical and medullary) and 5 inertia of moment were measured. The results were analyzed statistically. With aging, significant area change occurred mainly in diaphysis and female. In trochanteric area, no significant change was noted. With aging, total and medullary area were increased, but cortical area was not changed. In diaphysis, lateral bendingresistanceincreasedsignificantly. No inertia change was noted in trochanteric area. Anteroposterior bending resistance was constant with aging. In more than age 60, total area and medullary area were larger than that of others. Lateral bending resistance was higher especially in diaphysis. In diaphysis, with aging, the decreased properties is compensated with the increased lateral bending resistance by geometric remodeling. In trochanteric area, no compensation occur. With aging, especially in more than age 60, the higher rate of trochanteric fracture is expected.

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분만유형에 따른 초산모의 분만경험 지각과 어머니로서의 정체감비교 (A Comparisonison of Primiparas' Perception of Delivery Experience and Identity as the Mother According to Delivery Methods)

  • 조선영;고효정
    • 여성건강간호학회지
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    • 제5권1호
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    • pp.5-20
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    • 1999
  • This study was conducted to examine primiparas' perception of delivery experience and identity as the mother("Myself as the Mother" and "My Baby") according to delivery methods such as normal delivery and cesarean section. The result of this study summarized as follows. 1. The primiparas' perception of delivery experience according to delivery methods showed that the primipars who had normally delivered perceives the delivery experience more positively than those by cesarean section(t=4.88, p=0.000). This fact supported hypothesis 1 that "the primiparas group by normal delivery should perceive the delivery experience more positively that by cesarean section." 2. The primiparas who had delivered by cesarean section were more positive in the SD-Self score than those who had normally delivered at the time when four weeks passed after delivered, and there was a significant difference(t=-4.21, p\0.000). Therefore, hypothesis 2-1 that "the primiparas group who had normally delivered should be more positive in the SD-Self 1-2 days and 4 weeks after delivery than one who delivered by cesarean section" was rejected. 3. It was shown that the primiparas who had delivered normally were more positive in the SD-Baby 1-2 days 4 weeks after delivery than those who delivered by cesarean section(after-delivery 1-2 days : t=3.10, p=0.002 and after-delivery 4 weeks : t=2.15, p=0.034). Based on this fact, hypothesis 2-2 that "the primiparas group who had delivered normally should be more positive in the SD-Baby 1-2days and 4 weeks after delivery than those who had delivered by cesarean section"was supported. 4. Primiparas who had delivered by cesarean section appeared to have a positive identity as the mother by showing a more significant difference (t=7.96, p=0.000) 4 weeks after delivery than 1-2 days after delivery. In conclusion, we see that primiparas' perception of delivery experience and identity as the mother were different according to delivery methods. Thus, it is required to devise a nursing in tervention strategy to expand support from the health care system and opportunities to provide pre. post-delivery programs so that primiparas can have a positive perception of delivery experience and a positive identity as the mother. Based on conclusion stated above, the following suggestions are made. 1. As this study compared the perception of delivery experience and identity as the mother between prmiparas who had delivered normally and ones who had delivered by cesarean section, the further study on comparison between multiparas who had delivered normally and ones who had delivered by cesarean section is needed. 2. According to the results of this study, longitudinal study is needed to examine the difference and change in the formation of maternal identity. 3. According to the result of this study, a study is also needed to determine interaction between time for maternal identity and delivery methods.

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안와내벽파열골절의 내시경적 사골동내 충전에 따른 안와용적 변화 (Orbital Volume Change Resulted from Packing in Ethmoidal Sinus for Correction of Isolated Medial Orbital Fractures)

  • 김경훈;최수종;강철욱;배용찬;남수봉
    • 대한두개안면성형외과학회지
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    • 제10권1호
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    • pp.7-13
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    • 2009
  • Purpose: Endoscopic transnasal correction of the medial orbital fractures cannot be enable to confirm the reduction degree of orbital volume without imaging modalities. We have intended through this study to make a quantative analysis of preoperative orbital volume increment and the reduction degree of that after ethmoidal sinus packing by using CT scan. Methods: In this retrospective study, 22 patients were selected to evaluate the postoperative volume reduction, who took 2 CT scans which are pre- and postoperative under the same protocol. The postoperative CT scan was carried out in about 5 days after the operation with the packing inserted into ethmoidal sinus. The length of bony defect on each section was measured by PACS program and the area of defect was calculated by summing lengths on each section multiplied by the thickness of the section. When the outline of orbit on the slice is drawn manually with a cursor, PACS program measures the area automatically. Orbital volume was calculated from the sum of the area multiplied by the section thickness. Results: The mean dimension of fractured walls was $2.86{\pm}0.99cm^2$. The mean orbital volume of the unaffected orbits was $22.89{\pm}2.15cm^3$ and that of the affected orbits was $25.62{\pm}2.82cm^3$. The mean orbital volume increment of the affected orbits was $2.73{\pm}1.13cm^3$. After surgery, the mean orbital volume of the unaffected orbits was $22.46{\pm}2.73cm^3$ and the mean orbital volume decrease on the surgical side was $2.98{\pm}1.07cm^3$. The estimated correction rate was 118.30%. Conclusion: The orbital volume increment in fractured orbit showed linear correlation with the dimension of fractured area. The orbital volume changes after ethmoidal sinus packing also showed linear correlation with orbital volume increment in fractured orbit. This study showed the regressive linear correlation between the increment of orbital volume and the correction rate. To evaluate the maintenance of reduction state, we think that the further study should be done for comparative analysis of orbital volume change after removal of packing.

한강하구에서 하도변화와 식물천이의 상호작용에 따른 습지형성 기작 (Mechanism of Wetland Formation according to Interaction of River Bed Fluctuation and Plant Success in the Hangang River Estuary)

  • 이삼희;윤석준
    • 한국습지학회지
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    • 제24권4호
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    • pp.320-330
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    • 2022
  • 하구둑과 같은 횡단구조물이 없는 자연 하구인 한강하구는 바다와 하천을 연결하는 생태통로로서 생물종 다양성이 풍부하여 생태 가치가 높다. 한강하구에서는 유사분급이 입체적으로 다양하게 분포하여 기후변화 및 하천개발 등과 같은 여러 변화 요인에 따라 하상구조가 민감하게 변하는 특성이 나타난다. 이러한 현상은 하도육역화와 하도복단면 발달의 원인이 된다. 국가습지보호지역으로 지정된 장항습지에서는 하도 지형변화에 따라 식물천이가 현저하다. 본 연구 목적은 이에 대한 현장 조사를 실시하여 습지형성 기작을 규명하는 데 있다. 조사연구 결과, 인위적으로 조성된 것으로 추정되는 초기의 장항습지가 이후 성장하는 과정에 유량에 따른 하도 미지형 변화와 식물천이 사이에 상호 밀접하게 작용하는 것으로 드러났다. 즉 하상의 주재료(모래)가 아닌 부재(Sub-materials of river bed)인 점성의 표층 하상재료(워시로드 성질의 미세립사)가 선구식물(새섬매자기 등)에 포집되면서 복단면 형태(습지)로 성장하는 데 매개 역할을 한 것으로 나타났다. 습지가 하도복단면 형태로 발달한 후에는 선구식물이 다른 식물종으로 천이되는 양상도 나타났다.

고속도로 주행속도 변화에 영향을 미치는 도로기하구조 특성분석 : 제한속도 상향전후 비교를 중심으로 (Characteristics of Geometric Conditions Affecting Freeway Travel Speed : Focused on Speed Limit Change)

  • 홍성민;오철
    • 한국도로학회논문집
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    • 제16권5호
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    • pp.83-90
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    • 2014
  • PURPOSES : The purpose of this study is to identify the factors affecting the effectiveness of speed limit change that is defined as the amount of increased travel speed. METHODS : A ordered logit model was adopted to analyze the relationship between the change in travel speed and contributing factors. A stretch of Kyungbu freeway was selected for the analysis because the Korea expressway corporation has raised speed limit from 100km/h to 110km/h since September 1st in 2010. RESULTS : The results showed that geometric design elements, speeding cameras, and section length were identified as factors contributing the effectiveness. Contributing geometric design elements include the number of horizontal curves and vertical curves that do not meet the design requirement with 110km/h speed limit. CONCLUSIONS : The outcome of this study will be used for establishing various traffic operations and control strategies for freeway speed management.