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

  • Kim, Do-Hun;Yeo, Yeong-Gu;Park, Si-Han;Gang, Hong
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2003.11a
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    • pp.230-248
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    • 2003
  • In this work an integrated model for paper plants combining wet-end and dry section is developed and a model predictive control scheme based on the plant model is proposed. Closed-loop process identification method is employed to produce a state-space model. Thick stock, filler flow, machine speed and steam pressure are selected as Input variables and basis weight, ash content and moisture content are considered as output variables. The desired output trajectory is constructed in the form of 1st-order dynamics. Results of simulations for control of grade change operations are compared with plant operation data collected during the grade change operations under the same conditions as in simulations. From the comparison, we can see that the proposed model predictive control scheme reduces the grade change time and achieves stable steady-state.

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

  • Shin, Chang-Woong;Kim, Dong-Guk;Jeon, Dong-Chull;Kim, Eung
    • Ocean and Polar Research
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    • v.33 no.spc3
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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.

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

  • Kim, Moon Ki;Eom, Beom Gyu;Lee, Hi Sung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.23 no.3
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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.

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

  • Kang, S.B.;Ba, T.S.;Choi, J.B.;Choi, K.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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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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A Comparisonison of Primiparas' Perception of Delivery Experience and Identity as the Mother According to Delivery Methods (분만유형에 따른 초산모의 분만경험 지각과 어머니로서의 정체감비교)

  • Cho, Sun-Young;Koh, Hyo-Jung
    • Women's Health Nursing
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    • v.5 no.1
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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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Orbital Volume Change Resulted from Packing in Ethmoidal Sinus for Correction of Isolated Medial Orbital Fractures (안와내벽파열골절의 내시경적 사골동내 충전에 따른 안와용적 변화)

  • Kim, Kyoung-Hoon;Choi, Soo-Jong;Kang, Cheol-Uk;Bae, Yong-Chan;Nam, Su-Bong
    • Archives of Craniofacial Surgery
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    • v.10 no.1
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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.

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

  • Lee, Samhee;Youn, Sukzun
    • Journal of Wetlands Research
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    • v.24 no.4
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    • pp.320-330
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    • 2022
  • The Hangang river estuary, which is a natural estuary without structures such as estuary barrage, is an ecological pathway connecting the sea and rivers. Accordingly, Hangang river estuary has various species, and there is very valuable. Sediment classification in Hangang river estuary is three-dimensionally and diversely is distributed. Sediment classification in Hangang river estuary is also sensitively changed according to various factors such as climate change and river development. It is typically cause to landform and to develop a compound cross section. In Janghang wetland, the plant success is remarkable according to the morphological change at river bed. The purpose of this study is to identify the mechanism of wetland formation based on the observation on-site. As a result of the observation, Janghang wetland where was artificially created, has been grown according to the river bed change based on the flow rate and the plant success. The viscous surface layer material(fine grains of wash rod properties), which is not the main material(sand) of the river bed, but sub-materials of river bed, jas been settled on the pioneer plants(bolboschoenus planiculmis, etc.). It is an important role in the growth of a compound cross section and a wetland. After the wetland developed to the compound cross section, it is observed that the pioneer plants are transferred to other plant species.

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

  • Hong, Sungmin;Oh, Cheol
    • International Journal of Highway Engineering
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    • v.16 no.5
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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.