• Title/Summary/Keyword: D-efficiency

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A Study on the Hydraulic Characteristics of Rashig Super-Ring Random Packing in a Counter-Current Packed Tower (역류식 충전탑에서 Raschig Super-ring Random Packing의 수력학적 특성에 대한 연구)

  • Kang, Sung Jin;Lim, Dong-Ha
    • Clean Technology
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    • v.26 no.2
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    • pp.102-108
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    • 2020
  • In recent years, packed column has been widely used in separation processes, such as absorption, desorption, distillation, and extraction, in the petrochemical, fine chemistry, and environmental industries. Packed column is used as a contacting facility for gas-liquid and liquid-liquid systems filled with random packed materials in the column. Packed column has various advantages such as low pressure drop, economical efficiency, thermally sensitive liquids, easy repairing restoration, and noxious gas treatment. The performance of a packed column is highly dependent on the maintenance of good gas and liquid distribution throughout a packed bed; thus, this is an important consideration in a design of packed column. In this study, hydraulic pressure drop, hold-up as a function of liquid load, and mass transfer in the air, air/water, and air-NH3/water systems were studied to find the geometrical characteristic for raschig super-ring experiment dry pressure drop. Based on the results, design factors and operating conditions to handle noxious gases were obtained. The dry pressure drop of the random packing raschig super-ring was linearly increased as a function of gas capacity factor with various liquid loads in the Air/Water system. This result is lower than that of 35 mm Pall-ring, which is most commonly used in the industrial field. Also, it can be found that the hydraulic pressure drop of raschig super-ring is consistently increased by gas capacity factor with various liquid loads. When gas capacity factor with various liquid loads is increased from 1.855 to 2.323 kg-1/2 m-1/2 S-1, hydraulic pressure drop increases around 17%. Finally, the liquid hold-up related to packing volume, which is a parameter of specific liquid load depending on gas capacity factor, shows consistent increase by around 3.84 kg-1/2 m-1/2 S-1 of the gas capacity factor. However, liquid hold-up significantly increases above it.

Studies on the Quality and Utilization of Pumpkin Silages (호박 Silage의 품질(品質) 및 이용성(利用性)에 관(關)한 연구(硏究))

  • Kim, Y.K.;Kim, S.K.
    • Korean Journal of Agricultural Science
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    • v.3 no.1
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    • pp.77-84
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    • 1976
  • The preservation efficiency, quality and utilization of silage from 3 species of pumpkins (Mammoth pumpkin, Queensland blue pumpkin, Korean pumpkin) without and with 10, and 20% wheat bran additive were studied in this experiment. Silages were analysised and tested the chemical composition, pH and quality of silages between at 40-60 days and egg performance were carried out with mammoth pumpkin silage without additive. The results were summaried as follows. 1. The losses of all silage ware lower and similar as about 15% at 6 monthes following after silage-making but all raw pumpkins were spoilaged during the winter storaging. 2. The moisture content of silages were higher as about 97% in mammoth pumpkin silage, 94% in Queensland pumpkin silage and 91% in Korean pumpkin silage without additive and all nutrient content of silage without and with additive were depended on its content of raw silage material of pumpkins and wheat bran. The contents of moisture and N-free extract were slightly decrease but not significantly difference during the silaging and other contents were not so much changed. 3. Good quality of silage were made from all pumpkins with and without additive. Organic acid contents were 2.09-2.93% of lactic acid, 0.68-1.71% of acetic acid and 0% of butyric acid and it was pH 3.8-4.0 in silages. 4. Feed intakes, egg production and quality of egg were showed good result in 5.0 and 7.5% silage feeding group as D.M. base for egg performance. (P<0.01) 5. It was concluded that good quality of silage were made from pumpkins with and without wheat bran additive and it was suggested that poor quality feedstuff may be improved it feeding value by extended palatability with pumpkin additive silage.

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Dynamic Traffic Assignment Using Genetic Algorithm (유전자 알고리즘을 이용한 동적통행배정에 관한 연구)

  • Park, Kyung-Chul;Park, Chang-Ho;Chon, Kyung-Soo;Rhee, Sung-Mo
    • Journal of Korean Society for Geospatial Information Science
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    • v.8 no.1 s.15
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    • pp.51-63
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    • 2000
  • Dynamic traffic assignment(DTA) has been a topic of substantial research during the past decade. While DTA is gradually maturing, many aspects of DTA still need improvement, especially regarding its formulation and solution algerian Recently, with its promise for In(Intelligent Transportation System) and GIS(Geographic Information System) applications, DTA have received increasing attention. This potential also implies higher requirement for DTA modeling, especially regarding its solution efficiency for real-time implementation. But DTA have many mathematical difficulties in searching process due to the complexity of spatial and temporal variables. Although many solution algorithms have been studied, conventional methods cannot iud the solution in case that objective function or constraints is not convex. In this paper, the genetic algorithm to find the solution of DTA is applied and the Merchant-Nemhauser model is used as DTA model because it has a nonconvex constraint set. To handle the nonconvex constraint set the GENOCOP III system which is a kind of the genetic algorithm is used in this study. Results for the sample network have been compared with the results of conventional method.

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Optimizing Ingredients Mixing Ratio of Mungbean Pancake (빈대떡의 재료혼합비율의 최적화)

  • Lee, J.H.;Shin, E.S.;Kweon, B.M.;Ryu, H.S.;Jang, D.H.
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.8
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    • pp.1274-1283
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    • 2005
  • The sensory acceptability, texture profile analysis and nutritional evaluation were peformed in Korean traditional mungbean pancake (MPC) and modified MPC containing squid meat and soybean to standardize the recipes for healthy fast food market potentiality. Optimal ingredient formulations were revealed as mung-bean 55$\%$, pork 13$\%$ and vegetables 32$ \%$ for traditional MPC, and pork 3$\%$, squid 42$\%$ and soybean 55$\%$ for modified MPC using response surface methodology. Flavor and hardness correlated highly with overall accept-ability rather than appearance and color of traditional MPC. Higher squid levels raised adhesiveness, springi-ness and resiliences of modified MPC, but soybean decreased these textural attributes. Protein, lipid and total calorie of modified MPC were lower than those of traditional MPC. Computed protein efficiency ratio (C-PER) and degree of gelatinization of modified MPC were superior than traditional MPC.

Development of Intelligent ATP System Using Genetic Algorithm (유전 알고리듬을 적용한 지능형 ATP 시스템 개발)

  • Kim, Tai-Young
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.131-145
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    • 2010
  • The framework for making a coordinated decision for large-scale facilities has become an important issue in supply chain(SC) management research. The competitive business environment requires companies to continuously search for the ways to achieve high efficiency and lower operational costs. In the areas of production/distribution planning, many researchers and practitioners have developedand evaluated the deterministic models to coordinate important and interrelated logistic decisions such as capacity management, inventory allocation, and vehicle routing. They initially have investigated the various process of SC separately and later become more interested in such problems encompassing the whole SC system. The accurate quotation of ATP(Available-To-Promise) plays a very important role in enhancing customer satisfaction and fill rate maximization. The complexity for intelligent manufacturing system, which includes all the linkages among procurement, production, and distribution, makes the accurate quotation of ATP be a quite difficult job. In addition to, many researchers assumed ATP model with integer time. However, in industry practices, integer times are very rare and the model developed using integer times is therefore approximating the real system. Various alternative models for an ATP system with time lags have been developed and evaluated. In most cases, these models have assumed that the time lags are integer multiples of a unit time grid. However, integer time lags are very rare in practices, and therefore models developed using integer time lags only approximate real systems. The differences occurring by this approximation frequently result in significant accuracy degradations. To introduce the ATP model with time lags, we first introduce the dynamic production function. Hackman and Leachman's dynamic production function in initiated research directly related to the topic of this paper. They propose a modeling framework for a system with non-integer time lags and show how to apply the framework to a variety of systems including continues time series, manufacturing resource planning and critical path method. Their formulation requires no additional variables or constraints and is capable of representing real world systems more accurately. Previously, to cope with non-integer time lags, they usually model a concerned system either by rounding lags to the nearest integers or by subdividing the time grid to make the lags become integer multiples of the grid. But each approach has a critical weakness: the first approach underestimates, potentially leading to infeasibilities or overestimates lead times, potentially resulting in excessive work-inprocesses. The second approach drastically inflates the problem size. We consider an optimized ATP system with non-integer time lag in supply chain management. We focus on a worldwide headquarter, distribution centers, and manufacturing facilities are globally networked. We develop a mixed integer programming(MIP) model for ATP process, which has the definition of required data flow. The illustrative ATP module shows the proposed system is largely affected inSCM. The system we are concerned is composed of a multiple production facility with multiple products, multiple distribution centers and multiple customers. For the system, we consider an ATP scheduling and capacity allocationproblem. In this study, we proposed the model for the ATP system in SCM using the dynamic production function considering the non-integer time lags. The model is developed under the framework suitable for the non-integer lags and, therefore, is more accurate than the models we usually encounter. We developed intelligent ATP System for this model using genetic algorithm. We focus on a capacitated production planning and capacity allocation problem, develop a mixed integer programming model, and propose an efficient heuristic procedure using an evolutionary system to solve it efficiently. This method makes it possible for the population to reach the approximate solution easily. Moreover, we designed and utilized a representation scheme that allows the proposed models to represent real variables. The proposed regeneration procedures, which evaluate each infeasible chromosome, makes the solutions converge to the optimum quickly.

Effects of Sports Drink Including the Extract from Prunus mume on the Changes of Respiratory Variables, Heart Rate, and Blood Lactate Concentration in Submaximal Exercise (매실함유 음료섭취가 장시간 운동시 심박수, 호흡가스 변인 및 혈중 젖산농도 변화에 미치는 영향)

  • 김기진;배지현
    • Journal of the East Asian Society of Dietary Life
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    • v.9 no.2
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    • pp.177-187
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    • 1999
  • This study was designed to investigate the effects of sports drink including the extract from Prunus mume on the changes of oxygen uptake, minute ventilaton, heart rate, and blood lactate concentration during 1 hour treadmill running exercise corresponding to 75%VO$_2$max. Subjects were 16 male athletes(long distance runners and tennis players). The changing patterns of oxygen uptake and minute ventilation showed no significnat difference among all types of sports drink, but the minute vetilation of the placebo group showed a higher value than type I group during submaximal exercise. Although the changing patterns of heart rate and blood lactate concentration showed no significnat difference among all types of sports drink, but type E group showed a lower heart rate compared to Placebo group. And blood lactate concentration of placebo group showed a higher value compared to the value corresponding to lactate threshold during submaimal exercise. but the other types of sports drink showed a lower value of blood lactate concentration. Especially blood lactate threshold of type D and E groups showed a lower value (range from 1.44 to 2.00mM) during submaximal exercise. In these results, the sports drink including the extract from Prunus mume showed no significant effects to the changes of oxygen uptake, minute ventilaton, heart rate, and blood lactate concentration during 1 hour treadmill runnuing exercise corresponding to 75%VO$_2$max. But it could be suggested the positive effects of the intake of sports drink including the extract from Prunus mume on the inhibition of exercise-induced fatigue during submaximal exercise, because of the lower changing Patterns of heart rate, blood lactate concentration, and ventilation efficiency in this results.

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Analysis of Industrial Linkage Effects for Farm Land Base Development Project -With respect to the Hwangrak Benefited Area with Reservoir - (농업생산기반 정비사업의 산업연관효과분석 -황락 저수지지구를 중심으로-)

  • Lim, Jae Hwan;Han, Seok Ho
    • Korean Journal of Agricultural Science
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    • v.26 no.2
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    • pp.77-93
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    • 1999
  • This study is aiming at identifying the foreward and backward lingkage effects of the farm land base development project. Korean Government has continuously carried out farmland base development projets including the integrated agricultural development projects. large and medium scale irrigation projects and the comprehensive development of the four big river basin including tidal land reclamation and estuary dam construction for the all weather farming since 1962. the starting year of the five year economic development plans. Consequently the irrigation rate of paddy fields in Korea reached to 75% in 1998 and to escalate the irrigation rate, the Government had procured heavy investment fund from IBRD. IMF and OECF etc. To cope with the agricultural problems like trade liberalization in accordance with WTO policy, the government has tried to solve such problems as new farmland base development policy, preservation of the farmland and expansion of farmland to meet self-sufficiency of foods in the future. Especially, farmland base development projects have been challanged to environmental and ecological problems in evaluating economic benefits and costs where the value of non-market goods have not been included in those. Up to data, in evaluating benefits and costs of the projects, farmland base development projects have been confined to direct incremental value of farm products and it's related costs. Therefore the projects'efficiency as a decision making criteria has shown the low level of economic efficiencies. In estimating economic efficiencies including Leontiefs input-output analysis of the projects could not be founded in Korea at present. Accordingly this study is aimed at achieving and identifying the following objectives. (1) To identify the problems related to the financial supports of the Government in implementing the proposed projects. (2) To estimated backward and foreward linkage effects of the proposed project from the view point of national economy as a whole. To achieve the objectives, Hwangrak benefited area with reservoir which is located in Seosan-haemi Disticts, Chungnam Province were selected as a case study. The main results of the study are summarized as follows : a. The present value of investment and O & M cost were amounted to 3,510million won and the present value of the value added in related industries was estimated at 5.913million won for the period of economic life of 70 years. b. The total discounted value of farm products in the concerned industries derived by the project was estimated at 10,495million won and the foreward and backward linkage effects of the project were amounted to 6,760 and 5,126million won respectively. c. The total number of employment opportunities derived from the related industries for the period of project life were 3,136 man/year. d. Farmland base development projects were showed that the backward linkage effects estimated by index of the sensitivity dispersion were larger than the forward linkage effect estimated by index of the power of dispersion. On the other hand, the forward linkage effect of rice production value during project life was larger than the backward linkage effect e. The rate of creation of new job opportunity by means of implementing civil engineering works were shown high in itself rather than any other fields. and the linkage effects of production of the project investment were mainly derived from the metal and non-metal fields. f. According to the industrial linkage effect analysis, farmland base development projects were identified economically feasible from the view point of national economy as a whole even though the economic efficiencies of the project was outstandingly decreased owing to delaying construction period and increasing project costs.

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Dietary Effects of Post-fermented Green Tea by Monascus pilosus on the Body Weight, Serum Lipid Profiles and the Activities of Hepatic Antioxidative Enzymes in Mouse Fed a High Fat Diet (Monascus pilosus로 발효시킨 후발효 녹차가 고지방 식이 마우스의 체중과 혈청 지방함량 및 간 조직 항산화계 효소활성에 미치는 영향)

  • Lee, Sang-Il;Lee, Ye-Kyung;Kim, Soon-Dong;Yang, Seung-Hwan;Suh, Joo-Won
    • Journal of Applied Biological Chemistry
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    • v.55 no.2
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    • pp.85-94
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    • 2012
  • The anti-obese, hypolipidemic and hepatoprotective effects of post-fermented green tea by Monascus pilosus was tested with mice fed with high-fat diet for 7 weeks. The body weight gain and feed efficiency ratio (FER) in normal control group (NC), CHA (2% non-fermented green tea powder supplemented high-fat diet group) and mCHA (2% green tea powder post-fermented by M. pilosus supplemented high fat diet group) groups were significantly lower than those of high fat diet control group (HC). Epididymal fat weight in mCHA and NC were significantly lower than HC. The hepatic lipid peroxide was dramatically higher in HC than that of NC and was significantly lower in CHA and mCHA. In addition, dehydrogenase type activity of xanthine oxidoreductase in HC was lower than that of NC, but significantly higher than CHA and mCHA. In histopathological findings, hepatic fat accumulation in HC was higher than that of NC, CHA and mCHA. Antiobese, hypolipidemic and antifatty liver effect of green tea powder post-fermented by M. pilosus was slightly higher than that of non-fermented green tea. In conclusion, the constituents of green tea fermented by M. pilosus has been proven to not only inhibit obesity and hyperlipidemia but also decrease the hepatic fat accumulation in high fat diet-induced obese mice.

Presence of Leukemia-maintaining Cells in Differentiation-resistant Fraction of K562 Chronic Myelogenous Leukemia (만성 골수성 백혈병 K562세포의 분화 내성 분획에서 백혈병 유지 세포의 동정)

  • Lee, Hong-Rae;Kim, Mi-Ju;Ha, Gahee;Kim, So-Jung;Kim, Sun-Hee;Kang, Chi-Dug
    • Journal of Life Science
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    • v.23 no.2
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    • pp.197-206
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    • 2013
  • The present study investigated whether leukemia-maintaining cells reside in a differentiation-resistant fraction using a megakaryocytic differentiation model of K562 cells. Treatment with phorbol-12-myristate-13-acetate (PMA) significantly inhibited the colony-forming efficiency of the K562 cells. At a PMA concentration of 1 nM or higher, colony was not formed, but approximately 40% of K562 cells still survived in soft agar. Approximately 70% of colony-forming cells that were isolated following the removal of PMA after exposure to the agent were differentiated after treatment with 10 nM PMA for 3 days. The differentiation rate of the colony-forming cells was gradually increased and reached about 90% 6 weeks after colony isolation, which was comparable to the level of a PMA-treated K562 control. Meanwhile, imatinib-resistant variants from the K562 cells, including K562/R1, K562/R2, and K562/R3 cells, did not show any colony-forming activity, and most imatinib-resistant variants were CD44 positive. After 4 months of culture in drug-free medium, the surface level of CD44 was decreased in comparison with primary imatinib-resistant variants, and a few colonies were formed from K562/R3 cells. In these cells, Bcr-Abl, which was lost in the imatinib-resistant variants, was re-expressed, and the original phenotypes of the K562 cells were partially recovered. These results suggest that leukemia-maintaining cells might reside in a differentiation-resistant population. Differentiation therapy to eliminate leukemia-maintaining cells could be a successful treatment for leukemia if the leukemia-maintaining cells were exposed to a differentiation inducer for a long time and at a high dose.

Performance assessment of an urban stormwater infiltration trench considering facility maintenance (침투도랑 유지관리를 통한 도시 강우유출수 처리 성능 평가)

  • Reyes, N.J. D.G.;Geronimo, F.K.F.;Choi, H.S.;Kim, L.H.
    • Journal of Wetlands Research
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    • v.20 no.4
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    • pp.424-431
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    • 2018
  • Stormwater runoff containing considerable amounts of pollutants such as particulates, organics, nutrients, and heavy metals contaminate natural bodies of water. At present, best management practices (BMP) intended to reduce the volume and treat pollutants from stormwater runoff were devised to serve as cost-effective measures of stormwater management. However, improper design and lack of proper maintenance can lead to degradation of the facility, making it unable to perform its intended function. This study evaluated an infiltration trench (IT) that went through a series of maintenance operations. 41 monitored rainfall events from 2009 to 2016 were used to evaluate the pollutant removal capabilities of the IT. Assessment of the water quality and hydrological data revealed that the inflow volume was the most relative factor affecting the unit pollutant loads (UPL) entering the facility. Seasonal variations also affected the pollutant removal capabilities of the IT. During the summer season, the increased rainfall depths and runoff volumes diminished the pollutant removal efficiency (RE) of the facility due to increased volumes that washed off larger pollutant loads and caused the IT to overflow. Moreover, the system also exhibited reduced pollutant RE for the winter season due to frozen media layers and chemical-related mechanisms impacted by the low winter temperature. Maintenance operations also posed considerable effects of the performance of the IT. During the first two years of operation, the IT exhibited a decrease in pollutant RE due to aging and lack of proper maintenance. However, some events also showed reduced pollutant RE succeeding the maintenance as a result of disturbed sediments that were not removed from the geotextile. Ultimately, the presented effects of maintenance operations in relation to the pollutant RE of the system may lead to the optimization of maintenance schedules and procedures for BMP of same structure.