• 한국가구학회지
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• 제28권4호
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• pp.286-293
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• 2017

The dormitory, a common facility for college students, is being deployed and used in terms of both efficient use of space for students and comfortable living. Among them, I was in charge of the rest of the students in the dormitory and investigated and analyzed the dormitory bed which occupied the largest portion of the indoor space. The purpose of this study is to investigate the present condition of bed arrangement and the use condition of the university dormitory in Seoul, and finally to design the bed design which is practical and maximize storage for the students in the dormitory space that accommodates a large number of people, Respectively.

• 한국환경과학회지
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• 제3권3호
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• pp.263-271
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• 1994

A detachment of biofilm was investigated in an inverse fluidized bed biofilm reactor(IFRBR). The biofilm thickness, 5 and the bioparticle density, Pm were decreased by the increase of Reynolds number, Re and the decrease of biomass concentration, h. The correlations were expressed as $\delta$=6l.6+16.33$b_c$-0.004Re and Ppd=0.3+0.027$b_c$- 2.93x$l0^{-5}$ no by multiple linear regression analysis method. Specific substrate removal rate, q was derived by F/M ratio and biofilm thickness as q=0.44.+0.82F/M-5.Ix10$-4^{$\delta$}$. Specific biofilm detachment rate, bds was influenced by FIM ratio and Reynolds number as $b_{ds}$=-0.26+0.26F/M+ 2.17$\times$$10^{-4}$Re. Specific biofilm deachment rate in an IFBBR was higher than that in a FBRR(fluidized bed biofilm reactor) because of the friction between air bubble and the bioparticles.

• 대한기계학회논문집
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• 제16권2호
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• pp.325-335
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• 1992

In this work, direct contact 4-stage fluidized bed heat exchanger is experimentally studied to develop a new type of heat exchanger which recovers the energy contained in the high temperature waste gas exhausted from the industrial furnaces. A sand is used as a heat transfer medium in this experiment. To determine the optimum operating condition, 11 different perforated plates which have a different free area ratio with different hole diameter are used in the experiment. From the room temperature experiment, the pressure drop which is caused by fluidized bed formation is observed. The high temperature experiment is carried out to seek the optimum operating condition of high heat efficiency at low heat exchanger operation cost. The results of experiment are as following. The pressure drop in the high temperature condition can be predicted from the results of the room temperature experiment. And Nusselt number becomes smaller due to the increased interference between sand particles as Reynolds number increases when the dilute phase fluidized beds are formed in nigh temperature condition. But heat transfer amount through the total sand surface area become larger due to the large resident amount of sand. Considering the heat transfer amount and the heat exchanger operation cost, perforated plates which have either a 30% or 35% of free area ratio with 15mm of hole diameter are best fitted for our goal of this work. The values of .phi. which is a dimensionless number representing the absorption heat amount per unit sand rate are in the range from 0.4 to 0.5, when Reynolds number of waste gas ranges from 25-30 with these perforated plates.

• 한국지형학회지
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• 제25권2호
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• pp.15-29
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• 2018

The sediment transport process in a river reflects the process of geomorphological change in the watershed, influencesthe river bed variation and the river channel migration, and is a parametric phenomenon that exhibits a dynamic self-adjusting process. Sediment load is divided into bedload and suspended load depending on the dominant mechanism. Quantitative sediment load is important information for solving river problems. Because it is difficult and time consuming to measure bedload, compared to that ofsuspended load, data on the sediment transport load and the research required for the gravel-bed rivers are insufficient. This study is to analyze the ratio of the bedload to the total sediment load in gravel-bed rivers. The sediment load ratio in gravel-bed rivers increases with the flow rate per unit width, and the rate of the bedload varies more rapidly than the suspended load. The sediment transport efficiency coefficient has been affected by the ratio of the flow depth to the mean diameter of particles and has been dependent on the shear velocity Reynolds number. So $A^{\ast}$ and $B^{\ast}$ are introduced to compensate for the uncertainties such as bed materials, sediment transport, and flow velocity distribution, and the coefficient of bedload ratio has been presented. For the sediment load data in experimental channels and rivers, A* was 3.1. The dominant variables of $B^{\ast}$ were $u_*d_m/{\nu}$ in the gravel-bed and h/dm in the sand-bed. When $B^{\ast}$ the is the same, in the experimental channels the coefficient of bedload ratio was affected by the bed forms, but in the rivers it was of little difference between the gravel-bed and sand-bed.

• 보건행정학회지
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• 제17권2호
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• pp.18-32
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• 2007

The purpose of this study was a quantitative analysis for the influence of physician's assistants on national health insurance revenue and number of patients in clinic. The data was derived from the Korean national health insurance. That was complete enumeration. Dependent variables were measured by national health insurance revenue and number of patients. Independent variables were reported physician's assistants that the number of nurse, nurse-aid, technologist of clinical laboratory, physical therapist and radiologist in clinic. Confounding variables were classified by demand(region, number of inhabitants, number of clinics, number of bed per a hundred thousand persons) and supply(sex and age of representative, number of bed, subjective of medical treatment). On the multiple regression analyses, the physician's assistants that nurse, nurse-aid, technologist of clinical laboratory and physical therapist were statistically significant for outputs. But radiologist was statistically significant only for number of patient.

• 대한인간공학회지
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• 제31권2호
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• pp.389-396
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• 2012

Objective: The aim of this study is to design an auto showering system regarding bed type for old people or bedridden patients. Background: The rapid growth concerning the aging population leads to an increase in elderly bedridden patients living in senior care centers and hospitals where care givers have difficulty bathing older people with limited mobility. Method: In this study, a showering equipment for experiment was based on anthropometric and researching existing products. The nozzle position was optimized by showering tests and simulations using showering equipment. Results: The problems regarding the existing products were analyzed and the nozzle position was optimized through showering tests. The number, position, and spraying angle of the nozzle were optimized through showering simulations. The automatic showering system concerning bed type was designed by considering their results. Conclusion: When designing an automatic showering system, the most important design element involves determining the position of nozzle and angle of water injection and the number of nozzles. The system was developed by applying the results through user centered-research. Application: The user centered-research for developing products was applied directly in order to develop automatic baths, showering products etc. Furthermore, it was also available to be applied towards senior friendly products.

• 한국환경과학회지
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• 제22권1호
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• pp.25-35
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• 2013

The concentration of organic compounds was analyzed at each step of BAC process though $BDOC_{total/rapid/slow}$. Further, bacteria communities and biomass concentrations measured FISH and ATP methods were analyzed. The bed volume (BV) of steady state is different from that of based on assessment of organic compounds removal. Bed volumes in DOC, $BDOC_{rapid}$ and $BDOC_{total/slow}$ removal at steady state were around 27,500 (185.8 day), 15,000 (101.4 day) and 32,000 (216.2 day), respectively. A biomass didn't change after the bed volume reached 22,500 (152.0 day) according to analyzing ATP concentration of bacteria. The concentration of ATP was 2.14 ${\mu}g/g$ in BV 22,500 (152.0 day). The total bacterial number was $4.01{\pm}0.4{\times}10^7$ cells/g at the bed volume 1,150 (7.8 day) (the initial operation) and the number of bacteria was $9.27{\pm}0.2{\times}10^9$ at the bed volume 58,560 395.7 day) that increased more than 200 times. Bacterial uptrend was reduced and bacterial communities were stabilized since BV 18,720 (126.5 day). When BV were 1,150 (7.8 day), 8,916 (60.2 day), 18,720 (126.5 day), 31,005 (209.5 day), 49,632 (335.3 day), 58,560 (395.7 day), a proportion of total bacteria for the Eubacteria were 60.1%, 66.0%, 78.4%, 82.0%, 81.3% respectively. ${\gamma}$-Proteobacteria group was the most population throughout the entire range. The correlation coefficient ($r^2$) between Eubacteria biomass and ATP concentration was 0.9448.

• 한국병원경영학회지
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• 제4권1호
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• pp.41-65
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• 1999

This study was attempted to identify the factors affecting profitability of general hospital in Kyung-In Region. Operating profit to gross revenues and net profit to gross revenues were used as a proxy indicator for profitability of hospitals. The unit of analysis was hospital, and the data were collected 5 years data from 20 hospitals. The major findings are as follows; (1) The average operating profit rate was 1.03% and the net profit rate was -5.00% in twenty hospitals in the Kyung-In Region for the last five years. In terms of maximum surplus, the operating profit rate was 14% and net profit rate was 3.40%. In terms of maximum loss revenue, the operating profit rate was -16.56% and the net profit rate was -22.83%. (2) Since the year 1993, which was the starting year of this study, the operating profits and the net profits consistently decreased. (3) Analyzing the difference in profits among various hospital groups, the tertiary hospital group and the 501-1000 beds group exhibited the highest in operating profit rate. Also, among the higher grade number of beds in hospital group, per 100 beds group, the 41-50 beds group exhibited the highest in operating profit rate. There is a statistically significant difference in those groups(p<0.05, p<0.01). (4) In the health care delivery system, the profit gain in the secondary hospital was 51.5% and in the tertiary hospital was 72.4%. Based on the number of beds in each hospital group, the highest profit gain was 75.0% in the over 1001 beds group, and 71.4% in the 501-1000 beds group. Also, among the higher grade number of beds in hospital group, per 100 beds group, the 41-50 beds group exhibited 88.6% surplus. (5) According to the surplus difference based on the analysis of health care utilization, a group with over 31 patients in bed turnover rate, a group with over 96% in bed occupancy rate and group with over 9% in emergency cases to outpatient visits exhibited the highest profit gains. In addition, a group with over 301 patients in daily outpatient visits per 100 beds and group with 11-12 days average length of stay exhibited the highest profit gains. These results are statistically significant(p<0.05, p<0.01). (6) According to a stepwise regression analysis, the variables measuring the bed turnover rate, number of licensed beds, and number of outpatient visits per specialist explain 34.1% of the variation in operating profits. In terms of net profits, the new outpatient visits, the bed turnover rates and the number of general bed variables explain 30.6%. These results are statistically significant(p<0.01).

• 폴리머
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• 제27권1호
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• pp.61-68
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• 2003

본 연구에서는 도금폐수 중 니켈이온의 분리 회수를 위한 혼성 이온교환체의 제조 및 흡착 특성을 확인하였다. 니켈 흡착량은 이온교환체의 혼합비에 큰 영향이 없었으며, 비드상 이온교환수지 양이 증가할수록 증가하였다. 또한 Langmuir와 Freundlich흡착 등온식이 직선성을 보였으며 이로부터 니켈의 이온교환 친화력이 큰 것을 확인하였다. 또한 충전방식에 따른 압력손실은 다단충전법에서 적층수가 많아질수록 작아졌고, 혼합충전법에서는 비드 이온교환수지의 양이 증가할수록 압력손실은 감소하였다. 한편, 연속식 흡착실험 결과 다단충전방식의 경우 적층수가 증가할수록 초기 파괴 시간은 짧아졌으며, 최종 파괴 시간은 거의 동일한 것으로 나타났다. 반면, 혼합충전방식의 경우 이온교환섬유의 양이 증가할수록 흡착파괴 시간이 짧았으며, 이때 최대 흡착량은 각각 2.51 meq/g과 2.69 meq/g이었다. 한편, 모든 이온 교환체의 흡착된 니켈이온의 탈착은 10분 이내에 98% 이상 탈착되었다.

• 한국수자원학회논문집
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• 제35권2호
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• pp.195-201
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• 2002

본 연구에서는 자연하천의 만곡수로에서 종방향 유속으로 인해 현재보다 더 이상 횡 방향 경사의 변형이 일어나지 않아 세굴이 감소하고 하상이 횡방향으로 안정한 상태를 유지할 수 있는 적정 유속의 한계인 한계속도를 제시하였다. 한계속도의 이론 유도는 하상횡경모형의이론적 배경이 되는 운동량모멘트방정식으로부터 얻은 하상면 횡방향전단력성분과 이에 대응하는 하상전단력과의 힘의 평형으로부터 유도되었다. 이론식의 검증을 위해 4개 자연하천수로의 실측자료론 적용하여 계산치와 실측치를 비교한 결과 잘 일치하였다. 적용결과에서 보정계수와 만곡수로의 평균입자 Froude수는 밀접한 상관관계를 갖고 있는 것으로 나타났다.