• Title/Summary/Keyword: bed level change

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A Study on the Bed Change in Reservoirs (저수지 하상변동에 관한 연구)

  • Lee, Gwan-Su;Lee, Yeong-Seok;Jeong, Byeong-Geon
    • Journal of Korea Water Resources Association
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    • v.30 no.4
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    • pp.401-409
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    • 1997
  • This study aims to predict the bed elevation change of river and reservoir by compound water model, two-dimensional jet model and one-dimensional density current model, assuming that the river has a single channel and the reservoir has multiple channels. In numerical model, discharge and water level changes is obtained by flow continuity equation and flow momentum equation through double-sweep method, and then applied to sediment continuity equation to predict the scour and deposit of channel bed. The span ranged from the Bosung Dam to Mundueok Bridge at the upstream of Juam Dam, which is approximately 31km long (13km of river and 18km of reservoir), is taken as survey area.

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Analysis for the Effect of Channel Contraction for Sedimentation Reduction on the Flood Level and Bed Changes in the Lower Nakdong River (낙동강 하류의 퇴사저감을 위한 하폭축소방법이 홍수위변화 및 하상변동에 미치는 영향 분석)

  • Jang, Eun-Kyung;Ji, Un
    • Journal of Environmental Science International
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    • v.22 no.3
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    • pp.291-301
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    • 2013
  • Sediment from the upstream channel has been deposited near the Nakdong River Estuary Barrage (NREB) due to the mild slope and decreased velocity. The annual mechanical dredging to ensure the flood capacity has been performed to remove the deposited sediment. However, the dredging method is not considered as an effective countermeasure due to high cost and long time to operate. Therefore, many methods for sedimentation reduction have been proposed for NREB. Especially, the channel contraction method to mitigate sedimentation problem by changing the channel geometry from 2 km to 3 km upstream of NREB has been recently suggested as an effective countermeasure. However, there is the possibility that the channel contraction method induces flood level increase compared to original condition. Therefore, it is necessary to investigate quantitatively the flood level changes in the upstream and downstream section due to the channel contraction method for NREB. In this study, water level changes by 10% channel contraction of whole width has been evaluated using the HEC-RAS model and simulated with and without channel contraction for various flood discharge. As a result, water level in the section where the channel was contracted was decreased by 0.02 m and flood level at the upstream of channel contracted was increased up to 0.015 m for the 500-year flood.

A Study on Prevalence and Nursing Intervention of Bed Sore Patients who Received Regional Home Care Services (가정간호 대상자의 욕창발생 및 간호중재에 관한 조사연구)

  • Kim Keum-Soon;Cho Nam-Ok;Park Young-Suk
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.4 no.1
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    • pp.43-60
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    • 1997
  • This study was to identify the nursing intervention method in finding out the incidence, risk factor, prevention and treatment of bed sore cilents who received regional home care nursing services. The eleven home care nurse practitioners took the survey on 97 patients who received home care nursing service from Seoul City Nurses Association for one month from September 26 to October 26 1996. A modified version of Braden's bed sore assessment tool for bed sore risks and a tool for assessment of bed sore stage and measurement bed sore sizes by Bergstrom, Braden, Laguzza and Holman(1987) were as research tools for this study and a questionnare with 40 questions and 12 items on nursing activities was used to find out the prevention and treatment of bed sores. Also, two open ended questions were used on current approaches and efforts of the treatment being applied to clients. The finding of the study were summarized as following : 1. The rate of bed sore occurrence was 47.4% 2. The areas of bed sore occurrence were hip(28.9%), sacrum(18.6%), great trochanter(14.4%) and the average number of sore spots were 2.26 3. Two groups-one with bed sores and the other without-were studied to determine prediction factors for bed sore risks. Sensory function, humidity, level of activity, mobility, nutrition, skin friction and chapping and body temperature turned out to be statistically significant factors for bed sores. Also the age of clients turned out to be a individual characteristic variable significantly affecting the rate of bed sore occurrences. 4. The education for clients and family on systematic skin assessment and bed sores and practice of active/passive R.O.M. are mainly used as nursing activities for bed sore care. 5. The treatment method varied by stages of bed sores. Sometimes folk remedies like applying the powders of dried elm tree roots to sores were used. Good nutrition, frequent position change and skin care turned to be the most effective means to fast recovery of sores.

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Effects of Home Visiting Physical Therapy on Activites of Daily Living and Function in Disabled Persons Living at Home (가정방문물리치료가 재가장애인의 일상생활동작과 기능에 미치는 영향)

  • Park, Seung-Kyu;Ji, Hey-Young;Heo, Jae-Won
    • The Journal of Korean Physical Therapy
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    • v.23 no.2
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    • pp.61-68
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    • 2011
  • Purpose: The purpose of this study was to provide basic data for the effectiveness and the necessity of home visiting physical therapy through examining performance ability and functional changes in daily life activities by investigating the life of disabled persons living at home. Methods: After selecting 100 people with physical disabilities greater than level 3 and brain damage related disabilities living in Youngam-Gun, we conducted mobility tests according to a Modified Bathel Index (MBI), the Berg Balance Scale (BBS), and floor and bed movements? for Activities of Daily Living evaluation. We did this before the experiment and after doing home visiting physical therapy for 90 minutes at a time, once a week for 6 months Results: 1) Persons who live in a bed are higher than those who live in a floor. There was a significant difference between persons who live in a floor and those who live in a bed in the change in MBI and BBS scores after home visiting physical therapy. 2) Those with a musculoskeletal disorder had a significantly different change in MBI and BBS according to the type of disease and kind of disability. Those with neuropathy had a significantly different change in MBI. Those with physical disabilities showed a significant difference in MBI and BBS. Conclusion: A home visiting physical therapist can cause an improved performance ability and lead to the ability of disabled persons living at home to carry out activities of daily livingin a large part and the study for brain lesion disabilities except physical disabilities and stroke which occupy large proportion of disabled persons should be done.

Sediment Properties and Long-term Bed Change of Munsancheon (문산천의 유사특성 및 장기하상변동 예측)

  • Lee, Jae-Geun;Ahn, Jae-Hyun
    • Journal of Wetlands Research
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    • v.13 no.2
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    • pp.329-341
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    • 2011
  • This study was conducted with the national river, Munsancheon, which is located in Paju-si, Gyeonggi-do. The sediment discharge of Munsancheon was directly measured to analyze the sediment characteristics, and the results were used in the numerical model to predict the long-term river bed variation. The flow-total sediment discharge relation was derived using the measured total sediment discharge, and the results were compared with the total sediment discharge that was calculated using the existing prediction formula to derive a proper sediment discharge prediction method. In the actual measurements, the total annual sediment discharge was 5,478 ton/year, and the specific sediment discharge was 29.23 ton/$km^2$/year. The Ackers & White formula resulted in the values very close to the actual measurements. With the actual sediment discharge, geographical and hydrologic data as the input variables, HEC-6 and GSTARS models were comparatively analyzed. The test results showed that the HEC-6 model is suitable for the reliable prediction of the long-term river bed variation. Accordingly, the model was used for the long-term river bed variation prediction in this study. In the case of Munsancheon, deposition was continued in the downstream area and erosion occurred in the upstream area on the whole. It was expected that the stream would be stabilized in the river bed condition of 20 years later. The river bed variation was within 1 m, which was at the significance level. In the downstream area that is influenced by tide, however, the accumulation was continuously increasing within the section 2,000-7,000 m from the outlet. It seems that this should be considered in establishing the river management plans.

A study on the reduction of noise and vibration by acoustic resonance in the tube bank of a circulating fluidized bed combustion boiler (순환 유동층 보일러 관군의 음향공진에 의한 이상소음 발생 및 저감 연구)

  • Park, Eung-Kyu;Song, Keun-Bok;Kim, Won-Hyun;Joo, Won-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.101-106
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    • 2011
  • In the present paper, the phenomena of abnormal noise and vibration due to acoustic resonance of CFBC(Circulating Fluidized Bed Combustion) boiler was presented. The acoustic resonance which occurred in the gas path of CFBC boiler system was caused by coincidence of vortex shedding frequency of tube bank and acoustic natural frequency of duct and hopper. And, the phenomena of beating arose from the interference of two closed resonant waves at 66.4Hz and 70.8Hz. There are two control methods for acoustic resonance in this system. The first method is to change the vortex shedding frequency from the structural alterations on the tube bank. And the second method is to change the acoustic natural frequency of the gas path with the installation of anti-noise baffles. The second one which is relatively easy to apply, was adapted in this study. As a result, the noise and vibration level have been decreased by 41dB and 94% at 66.4Hz, respectively. And the improvement of noise and vibration at 70.8Hz was identified by sensory evaluation.

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Experimental Study on Mechanism Analysis of Headcut Erosion in the Noncohesive Sediment Bed (비점착성 하상에서의 두부침식 메커니즘 분석에 관한 실험 연구)

  • Ji, Un;Jang, Eun-Kyung;Kang, Jin-Wook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.2
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    • pp.1500-1506
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    • 2015
  • The headcut erosion at the confluence section of a mainstream and tributary can migrate up the tributary streams, and rapid degradation can threaten the stability of hydraulic structures installed in the channel. Therefore, quantitative analysis for the development and mechanism of headcut erosion is needed to prevent damage due to the headcut. In this study, hydraulic experiments for headcut erosion in the channel with noncohesive materials were performed and the knickpoint movement and final bed slope change were analyzed based on the different hydraulic conditions. As a result, the knickpoint movement was 1.5 times faster when the difference in velocity between the upstream and downstream sections was 2.5 times greater and the central part of the cross-section was eroded and collapsed earlier than the left and right sides. The movement length of headcut erosion was longer and the final bed slope was milder as the velocity difference between the upstream and downstream sections was increased. This study showed that a correlation between the knickpoint movement and bed slope change by headcut erosion and the water level difference of upstream and downstream sections was not constant compared to the velocity difference.

An Analysis on the Stage-Discharge Relation Curve with the Temporal Variation of the River Bed -at Indogyo Station of the Han River- (하상(河床) 경년변화(經年變化)에 따른 수위(水位)-유량(流量) 관계곡선(關係曲線)의 해석(解析) -한강(漢江) 인도교지점(人道橋地點)을 중심(中心)으로-)

  • Cheong, Heung Soo;Lee, Won Hwan;Lee, Jae Joon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.8 no.3
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    • pp.61-71
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    • 1988
  • The stage-discharge relation curve(rating curve) is the basic formula in hydrologic analysis. It plays an important role in converting to the discharge from available flood water level data including the daily mean stage. However, the river induces a cross section change at the gauging station because of the composed material of the river bed and three processes of the stream flow; i.e., erosion, transportation, and sedimentation. Rating curve has to be revised according to the temporal variation of the river bed due to the those factors. In this study, the basic rating curve is developed with respect to the current river bed to convert the existing rating curves and also to seize the hydraulic and geometric characteristics for the temporal variation of the river bed, relationships among the basic rating curve and the existing rating curves, water level, cross sectional area, and flow velocity are analyzed. Indogyo station, which is not only the key station of the Han river but also greatly changed the river bed after completion of the Han river development plan during the year 1983 to 1986, was chosen for the study. In this study, the river bed is assumed in a dynamic equilibrium condition. The basic rating curve is developed using hydrologic data of the physical year of 1987. For a given discharge, relationships for conversion of previous data, stage and velocity, the current one are formulated. To verify the usefulness of the relationships, stage-cross sectional area and stage velocity formula are also derived. Both hydrologic method using continuity equation and statistical method by the rating curve are compared and checked, then the validation of the both are positively shown.

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A Study on Comparison of the Characteristic Test of Discharge Water Flowmeters (Electromagnetic Flowmeter, Parshall Flume) (방류수 유량계(전자기유량계, 파샬플룸)의 특성평가 연구)

  • An, Yang-ki;Kim, Jee-young;Kim, Kum-hee;Jang, Hee-soo;Jung, Jung-pil;Choi, Jong-woo
    • The KSFM Journal of Fluid Machinery
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    • v.18 no.6
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    • pp.57-62
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    • 2015
  • The test of comparing liquid flow calibration system (approved by KOLAS) for accuracy and structure change test was performed in the test bed in order to evaluate the typical characteristics of the electromagnetic flow meters and parshall flume that are generally used in the water discharging facilities. The results of the accuracy comparing test with liquid flow calibration system showed the error of less than 2%. Pharshall plume got error up to -8.3% (low flow) from the flow rate test, but less than 4% from the accumulated flow test because of offset error at high flow rate and low flow rate. Evaluation of structual change test was tested with only parshall flume using structure and it consisted of installation angle (parshall flume and level sensor) and position change. Installation angle, water level sensor angle and position changing test for parshall flume had errors of 3.1%~-9.2%, 0.4%~-5.6% and 0.2%~1.3% respectively. Especially, the error showed the largest increase when the water level sensor measured the point of decreased flow by the structure change. Therefore, error factors (change of straight pipe length, installation of obstacle or effect of foreign substances on water level sensor) that can often occur in the field should be derived and the research for optimized installation method should be carried out continuously.

A Comparative Study on the Effect of Gel Pad, Sheepskin and Sponge on Prevention and Treatment of Decubitus Ulcers (양털, Gel Pad 및 Sponge의 욕창예방 및 치료효과에 관한 연구)

  • 이은옥;김매자
    • Journal of Korean Academy of Nursing
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    • v.4 no.3
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    • pp.93-104
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    • 1974
  • Regardless of a patient's diagnosis, the care of his skin has been a primary concern of nurses throughout the years. Nurses has washed, dried, and rubbed the skin and have changed his position so as to keep the patient's skin in good condition and to protect him from pressure sores. However, we still find many-patients suffering from the pressure sores which may take many mothers or years of treatment and cost a lot to be repaired. In view of expensive cost for treatment of the sores and low ratios of nursing staff per patient for intensive nursing care, prophylaxis of the bed sores with sufficient aids is extremely important both for patients and for nurses. Therefore, the unique purpose of this study was to determine whether sponge is good enough to treat and prevent the pressure sore as compared with gel pad and sheepskin. Sixty patients in the age range of 15 through 45 who were in unconscious status or have difficulty of mobility were chosen between January and March of 1974 at Seoul National University Hospital. They were randomly assigned to each treatment and observed on every 4th day with regard to level of consciousness, status of mobility, moisture or dryness of the bed, general skin condition, intake of nutrition, vital signs and intervals of position change in comparison with the changes of skin over the bony prominences. The study results were reviewed in a statistical method analysis of valiance-to obtain the following findings: 1. There was no significantly different changes of skin over the sanctum or the trochanter in each group using get pad, sheepskin or sponge. It means that we may substitute sponge for expensive gel pad or sheepskin. 2. There was no significant difference among mean changes of patient's skin in relation to sheepskin, gel pad and sponge. 3. There was no significant changes of patient's akin in relation to level of consciousness, status of mobility, intake of nutrition, general skin condition, temperature, blood pressure or interval of position change. 4. There were no meaningful interactions between each treatment and level of consciousness, moisture or dryness of the bed, intake of nutrition, general skin condition, temperature or blood pressure. 5. Sheepskin and gel pad had significantly better influence on patients with limited mobility than on patients with immobility, and sponge on patients with immobility on than patients with limited mobility, 6. Sheepskin and sponge had meaningfully totter influence on patients changing position at below 2-hour interval, gel pad at 2-4-hour interval, sheepskin at 4-6-hour interval, and three of them at above 6-hour interval.

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