• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.181-191
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• 2014

Modern commercial greenhouse requires the use of advanced climate control system to improve crop production and to reduce energy consumption. As an alternative to classical sensor-based control method, this paper introduces a model-based control method that consists of two models: the predictive model and the evaluation model. As a first step, this paper presents straightforward models to predict the effect of natural ventilation in a greenhouse according to meteorological factors, such as outdoor air temperature, soil temperature, solar radiation and mean wind speed, and structural factor, opening rate of roof ventilators. A multiple regression analysis was conducted to develop the predictive models on the basis of data obtained by computational fluid dynamics (CFD) simulations. The output of the models are air temperature drops due to ventilation at 9 sub-volumes in the greenhouse and individual volumetric ventilation rate through 6 roof ventilators, and showed a good agreement with the CFD-computed results. The resulting predictive models have an advantage of ensuring quick and reasonable predictions and thereby can be used as a part of a real-time model-based control system for a naturally ventilated greenhouse to predict the implications of alternative control operation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2779-2785
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• 2009

Among the livestock, chickens are raised because of the merit ingested protein in low-priced cost of production and are primary livestock increased the consumption of meat. The factors of influencing condition, odor is the most important factor. Odor substances are ammonia, amines, hydrogen sulfide and mercaptan which come from night soil. Livestock are prevented from rearing by means of these odor substances. Though the henhouse is heated using hot air type heater in the winter season, it is ventilated for the control of odor because of the increase of odor concentration. In the present work, composite catalytic system combined the existing facilities(hot air type heater) with catalytic system was developed, it could controled odor and hazardous gas using the oxidation/reduction reaction without extra operating cost. Moreover, the purpose of this work is to develop the catalysts which are cost competitive and can maximize energy efficiency. The catalysts are noble metal(Pt-Rh) and composite transition metal(Mn) type.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.4
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• pp.392-402
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• 2010

Black carbon (BC) concentrations were measured with an aethalometer (AE-16, 880 nm) at time interval of 5-min at an urban site of Gwangju over a year 2008. 24-hr filter-based integrated measurements of $PM_{2.5}$ particles were also made at the same site during the winter and summer intensive periods to test any optical loading bias in the raw BC data measured by aethalometer. BC concentration was higher in winter than in summer, possibly due to increase in emissions from energy consumption and poor dispersion with reduction of boundary layer in winter. Also temporal cycles of BC indicate that short-term transient spikes were common, occurring primarily during the rush-hour periods. A similar feature was also observed in diurnal concentration cycle of CO, mainly emitted from motor vehicles. When both low wind speed and weather patterns such as mist, haze and etc were combined, high BC concentrations frequently occurred. The amount of optical loading effect described by the "k" factor showed the seasonal variation, ranging from 0.0003 to 0.0036. This implies that optical loading effect is not seen at all times. From the comparison between the filter-based elemental carbon (EC) and aethalometer BC data, it was found that the loading compensated BC values were more reasonable than the raw BC ones reported from the aethalometer.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.3
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• pp.101-108
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• 2004

A 16-bit adiabatic ALU(arithmetic logic unit) is designed. A simplified four-phase clock generator is also designed to provide supply clocks for the adiabatic circuits. All the clock line charge on the capacitive interconnections is recovered to recycle energy. Adiabatic circuits are designed based on ECRL (efficient charge recovery logic) using a 0.35${\mu}{\textrm}{m}$ CMOS technology. The post-layout simulation results show that the power consumption of the adiabatic ALU including supply clock generator is reduced by a factor of 1.15-1.77 compared to the conventional CMOS ALU with the same structure.

• Nutritional Sciences
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• v.6 no.4
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• pp.232-238
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• 2003

Cardiovascular disease (CVD) is one of the most common causes of death in elderly Koreans, and HDL-cholesterol is known to have a pivotal role in protecting against CVD. This study was undertaken to study the relationships between plasma HDL-cholesterol levels and dietary, anthropometric, and biochemical factors in elderly Koreans. The 102 subjects, who were over 60 years old, were classified into two groups based on their plasma HDL-cholesterol levels: a risk group with plasma HDL-cholesterol < 40mg/dl in men or HDL-cholesterol < 50mg/d1 in women, and a control group with higher HDL-cholesterol levels. The subjects' mean intakes of energy, calcium, zinc, vitamin A, vitamin $B_2$, vitamin E, and folate did not meet the Korean RDA for elderly people. Vitamin $B_2$ and folate intakes were significantly lower (p<0.l) in the risk group compared to the control group. The consumption of seaweed was significantly lower (p<0.05), and fish intake was 33% lower, in the risk group compared to the control group. Subjects in the risk group showed a higher BMI, waist/hip ratio, triceps skinfold thickness, and % body fat, compared to control subjects. Plasma triglyceride levels and values of the atherogenic index were significantly higher (p<0.00l) in risk group subjects. Significant negative correlations between HDL-cholesterol level and plasma triglyceride level (r= 0.37), and values of the atherogenic index (r=-0.74), were found. In summary, subjects with low levels of HDL-cholesterol were found to have relatively low intakes of vitamin B$_2$, folate, and seaweed, and higher levels of the CVD risk factors: body fat, plasma TG, and AI. These results suggest that plasma HDL-cholesterol levels can be modified by dietary, anthropometric, and hematological means.

• Nutrition Research and Practice
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• v.14 no.1
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• pp.55-61
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• 2020

BACKGROUND/OBJECTIVES: Osteoporosis is characterized by low bone mass and results in vulnerability to fracture. Calcium and vitamin D are known to play an important role in bone health. Recently, potassium has been identified as another important factor in skeletal health. We examined the link between potassium intake and bone health among the Korean older adult population. SUBJECTS/METHODS: This retrospective, cross-sectional study included 8,732 men and postmenopausal women over 50 years old who completed the Korean National Health and Nutrition Survey (KNHANES) between 2008 and 2011. Potassium consumption was evaluated using a 24-hour recall method. Bone mineral density (BMD) was measured at three sites (total hip, femur neck, and lumbar spine) by dual-energy X-ray absorptiometry (DEXA). Multinomial logistic regression was used to examine the link between potassium intake and prevalence of osteoporosis and osteopenia, after controlling for potential confounding variables. RESULTS: The BMD of the total femur and Ward's triangle were significantly different according to the potassium intake among men (P = 0.031 and P = 0.010, respectively). Women in the top tertile for potassium intake showed higher BMD than those in the bottom tertile at all measurement sites (all P < 0.05). Daily potassium intake was significantly related to a decreased risk of osteoporosis at the lumbar spine in postmenopausal women (odds ratios: 0.68, 95% confidence interval: 0.48-0.96, P trend = 0.031). However, the dietary potassium level was not related to the risk of osteoporosis in men. CONCLUSION: Current findings indicate that higher dietary potassium levels have a favorable effect on bone health and preventing osteoporosis in older Korean women.

• Korean Journal of Adult Nursing
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• v.22 no.6
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• pp.644-652
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• 2010

Purpose: The purpose of this study was to analyze the relationship among life style, body composition and Bone Mineral Density (BMD) in community dwelling Korean adults. Methods: Data were collected from 140 adults who participated in a health check-up program at community health departments in D city, Choong-chung providence. Subjects' life style was assessed with a structured interview survey. Body composition analyses were performed by the bioimpedence method and BMD was measured by peripheral dual energy X-ray absorptionmetry. Results: Among the subjects, 39.3% showed normal BMD values, 50.7% were osteopenic and 10% were assessed as osteoporotic. BMD was significantly different by gender, age, education, economic status and BMI. Subjects who had three or more meals/day had higher BMD then who had less than three meals (t=-2.273, p=.026). BMD was not influenced by regular exercise, alcohol consumption, or smoking. In terms of body composition, there was a significant relationship between fat free mass and BMD (r=.172, p=.043). Conclusion: Implementing an osteoporosis prevention program would be warrented considering the significant proportion of osteopenic or osteoporotic subjects. Regular eating habit with three meals for adequate nutrition need to be emphasized to prevent further bone loss in this population. Among the body composition, fat free mass seem to be the mostly predicting factor for BMD.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.465-469
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• 2013

In this study, we investigated the feasibility of torrefied OPF (oil palm fronds) as the fuel. The torrefaction was performed at 200, 250, 300 and $350^{\circ}C$ during 1 and 2 hours, respectively. As raising the torrefaction temperature and increasing the processing time, the GHV (gross heating value) of torrefied OPFs was increased. Moreover, we found that the torrefaction temperature is more important factor than the processing time. However, the proper torrefaction temperature was asked because the higher torrefaction temperature leaded to the lower torrefied OPF yield. TGA (thermo-gravimetric analysis) data released that the torrefaction at $250^{\circ}C$ could significantly decompose the hemicellulose and the almost cellulose was decomposed at $300^{\circ}C$. In addition, the grindability of biomass was improved after torrefaction, so that it can reduce energy consumption in comminution.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.962-968
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• 2013

Problem of greenhouse gases associated with global warming and the world rise in fuel oil prices due to the depletion of fossil fuel has attracted attention. For this reason, maritime transport business, has shown interest in green-ship technology to reduce the consumption of fuel and reduce greenhouse gas for environmental protection. Power system of the ship is one of the most important factors for safe operation. Therefore, at design of ship power system, most of existing vessel used comparative large capacity generator in order to respond peak load such as bow thruster, crane and etc. In the navigation of ship, marine generators most would be operated at low load operation. In the low load operation of the generation rate of 50% or less, the operation efficiency of the generator it deteriorated, to consume more fuel oil. It also, it means that adversely effect the life of the generator. In this paper, studied how to apply for a secondary battery in container ship that relatively frequent arrival and departure in port. As a result, in order to apply the secondary battery to increase the operating efficiency of the generator during the voyage, it was confirmed that it is possible to reduce fuel consumption.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.1
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• pp.57-63
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• 2011

Changes in food preferences and dietary habits of Korean prone to decrease consumption of the traditional energy source, rice. The exceeding condition of rice production in Korea is now not only impacting on the profit structure of farmers but also threatening food security. Although there have been several efforts to increase rice consumption rate, by developing various processed foods using rice flour, grain hardness of rice has been the most significant limiting factor. In this study, we addressed the suitability of the Namil(SA)-flo1, a mutant rice line has floury endosperm, in terms of producing rice flour by using dry-milling method, which is lower cost and more eco-friendly than other available methods such as wet-milling. Rice flour of the Namil(SA)-flo1 exhibited superior physico-chemical characteristics to any other check varieties including the wild type, Namil, in terms of distribution of granule sizes and content of damaged starch.