• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.901-904
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• 2008

Immense quantities of coal combustion by-products are produced every year, and only a small fraction of them are currently utilized. Therefore, this study investigated and analyzed the applications of porous concrete for the efficient utilization of bottom ash. This study examines on application of polymer to improve strength properties of porous concrete using coal-ash. As the results, when the mixing ratio of bottom ash increases, void ratio and coefficient of permeability of porous concrete increases, but its strength decreases. Also, as the mixing ratio of polymer increases, its void ratio and coefficient of permeability decreases. When specific amount of polymer is mixed, we can find its strength properties are improved.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.7
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• pp.981-986
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• 2013

The nutrient digestibility, nitrogen balance and in vivo metabolizable energy supply of Mucuna pruriens whole pods fed to growing Pelibuey lambs was investigated. Eight Pelibuey sheep housed in metabolic crates were fed increasing levels of Mucuna pruriens pods: 0 (control), 100 (Mucuna100), 200 (Mucuna200) and 300 (Mucuna300) g/kg dry matter. A quadratic (p<0.002) effect was observed for dry matter (DM), neutral detergent fibre (aNDF), nitrogen (N) and gross energy (GE) intakes with higher intakes in the Mucuna100 and Mucuna200 treatments. Increasing M. pruriens in the diets had no effect (p>0.05) on DM and GE apparent digestibility (p<0.05). A linear reduction in N digestibility and N retention was observed with increasing mucuna pod level. This effect was accompanied by a quadratic effect (p<0.05) on fecal-N and N-balance which were higher in the Mucuna100 and Mucuna200 treatments. Urine-N excretion, GE retention and dietary estimated nutrient supply (metabolizable protein and metabolizable energy) were not affected (p>0.05). DM, N and GE apparent digestibility coefficient of M. pruriens whole pods obtained through multiple regression equations were 0.692, 0.457, 0.654 respectively. In vivo DE and ME content of mucuna whole pod were estimated in 11.0 and 9.7 MJ/kg DM. It was concluded that whole pods from M. pruriens did not affect nutrient utilization when included in an mixed diet up to 200 g/kg DM. This is the first in vivo estimation of mucuna whole pod ME value for ruminants.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.7
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• pp.770-775
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• 2006

Biofilters packed with various materials commonly show problems such as low performance and clogging in a long-term operation. Recently, a bioactive foam reactor(BFR) using surfactants has been suggested to ensure efficient and stable VOCs removal performance. This study was mainly conducted to investigate the feasibility of the BFR system using styrene as a model compound. An abiotic md a biotic tests were conducted to estimate a mass transfer coefficient($K_La$) and a specific substrate utilization coefficient(k) for the BFR, showing the rate of mass transfer was greater in the BFR than in other diffuser systems. A dynamic loading test also indicated that the performance of the BFR was stable under a shock loading condition. Furthermore, the maximum elimination capacity of the BFR was determined to be 109 $g/m^3/hr$ for styrene, which was much higher than those for biofilter systems generally reported in the literature. Overall, the experimental results suggest that the BFR be a potential alternative to the conventional packed-bed biofilters.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.489-495
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• 2015

A fundamental mathematical model for mass transfer processes has been used to understand the air pollution control process in biotrickling filtration and to evaluate the mass transfer coefficients of gas/liquid (trickling liquid), gas/solid (biomass) and liquid/solid based upon experimental results and mathematical model calculations for selected operating conditions. The mass transfer models for the utilization of the steady-state mass balance for gas/liquid, and dynamic mass balance model for gas/solid & liquid/solid in biotrickling filters were established and discussed. The mass transfer model considered the reactor to comprise finite sections, for each of which dynamic mass balances for gas/solid and liquid/solid system were solved by numerical analysis code (numerical iteration). To determine the mass transfer coefficients ($K_La$) of gas/liquid, gas/solid & liquid/solid in a biotrickling filter, the calculation results based upon mass balance equation was optimized to coincide with the experimental results for the selected operating conditions. Finally, this study contributed the development of experimental methods and discussed the mathematical model to determine the mass transfer coefficients in a biotrickling filtration for air pollution control.

• Journal of Biosystems Engineering
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• v.25 no.6
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• pp.497-502
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• 2000

For the analysis of geothermal energy utilization in agriculture the relations between soil temperature and geographical variables such as latitude longitude and sea level in Korea were analyzed and the regression equations were suggested among them. The measured soil temperature data for four years in eighteen cities were used to get the soil temperature fitting equation depending on the soil depth and the time of year in each city. The mean correlation coefficient for those data fitting was 0.980. the correlation coefficient of regression analysis for the mean soil temperature($T_{m}$) on the geographical variables such as latitude longitude and height above sea level was 0.958 and those for soil surface temperature amplitude(Tss) and phase constant(tp) were 0.889, 0.835, respectively. The relation between the apparent thermal diffusivity of the soil and the three geographical variables was not significant. The regression equations for the mean soil temperature($T_{m}$) soil surface temperature amplitude(Tss) and phase constant(tp) adopting latitude($X_{1}$) longitude($X_2$) height above sea level($X_3$) were as follows : $T_{m}$=50.049 - $0.849X_1$-$0.03131X_2$-$0.00622X_3$Tss=-6.970 +$0.584X_1$+$0.00530X_2$-$0.00214X_3$tp=70.353 - $1.404X_1$+ $0.02098X_2$+ $0.00312X_3$

• Journal of Wetlands Research
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• v.13 no.3
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• pp.633-641
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• 2011

The Philippines is known for its abundant water resources such as the rainfall, where it has a mean annual rainfall range from 965 to 4,100mm. Due to the rapid urbanization of the country, the population in Metro Manila has been continuously increasing hence, the demand for a potable water supply also increases. To mitigate the scarcity of potable water supply, utilization of the water resources should be practiced. Rainwater harvesting is one way to utilize the rainfall runoff. This study analyzedthe potentiality of the rainwater harvesting on residential areas in Metro Manila. A water balance method based spreadsheet was used with input parameters including daily rainfall, catchment area, runoff coefficient, population and the water demand. The efficiency of the domestic water tank was analyzedusing the three different climatic conditions (i.e., minimum, median andmaximum annual rainfalls) and three different types of toilets (i.e., inefficient, conventional and dual-flush toilets). Furthermore, the overflow volume was used to determine which size of rainwater storage was more appropriate for the study area. The results of the study showed that for the three types of rainfall years, only the conventional and dual-flush toilets were suitable for the utilization of rainwater harvesting. The utilization of the $60m^3$ storage tank was sufficient for supplying the demandsof the 90 houses only for a small period of time, 3 months. Based from this study, to fully sustain the long-term water demand of the houses, the enlargement of the tank size having a capacity of 1,100 to $2,500m^3$ is ideal.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.232-242
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• 2014

We investigated the interspecific competition between the harmful dinoflagellate Cochlodinium polykrikoides and diatom Skeletonema sp. based on the utilization and uptake of dissolved organic nutrients. C. polykrikoides and S. costatum were able to grow using dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP) as well as dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP). This result indicates that the utilization of dissolved organic nutrients may play a role in surviving strategy in the DIN or DIP-limited environments. The half-saturation constants (Ks) of urea and glycerophosphate (glycero-P) calculated from uptake kinetics experiment of C. polykrikoides was lower than those of Skeletonema sp. This result indicates that Skeletonema sp. have higher affinity for dissolved organic nutrients, such as urea and glycero-P, than C. polykrikoides. Although Skeletonema sp. have higher affinity of dissolved organic nutrients, C. polykrikoides could effectively uptake for urea and glycero-P at sub-saturating nutrient concentrations (${\alpha}$ (${\rho}_{max}/Ks$) of C. polykrikoides was higher than Skeletonema sp.. Therefore, C. polykrikoides by utilization and effectively uptake of dissolved organic nutrients under monoculture may have an advantageous position in the interspecific competition with Skeletonema sp. in the low nutrient environments.

• Women's Health Nursing
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• v.25 no.3
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• pp.329-344
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• 2019

Purpose: This study aimed to identify utilization of the work-family support policy (WFSP) and factors affecting retention intention among Korean female military officers. Methods: This cross-sectional survey recruited 103 married female officers from the Korean Army, Navy, and Air force with preschool-aged children through convenience and snowball sampling. Via online surveys from June to November, 2018, the participants self-reported retention intention, work-family conflict, job satisfaction, and utilization of the WFSP. The data were analyzed using descriptive statistics, independent t-tests, one-way analysis of variance, Pearson's correlation coefficient, and multiple linear regression. Results: Retention intention ($22.29{\pm}5.98$) was reported at the mid-level, lower than scores reported in the literature for female workers. Work-family conflict ($32.51{\pm}5.29$) and job satisfaction ($63.10{\pm}7.45$) were above the midpoint levels. Use of maternity leave (100.0%) and parental leave (92.2%) was high, especially compared to the rates of child-care day off (20.4%) and parenting time (20.4%). 'Noticeable increases in childcare services within the army' (22.8%) was reported as the supportive measure needed the most by female military officers. Job satisfaction (${\beta}=.43$, $p{\leq}.001$), the use of parenting time (${\beta}=-0.29$, p=.002), living type (${\beta}=-.18$, p=.043), and service type (${\beta}=-.16$, p=.035) significantly influenced retention intention. Conclusions: The findings highlight the priority areas of importance within the WFSP and suggest that a family-friendly culture can improve female officers' retention intention. Accordingly, policy changes at the Ministry of National Defense improving the system to enhance a family-friendly culture in the military is expected to strengthen the retention intention of female officers and contribute to excellence in the military workforce.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.798-809
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• 2020

Evidence-based policymaking and assessments for scientific administration have increased the importance of statistics (data) utilization. Statistics can explain specific phenomena by providing numerical values and are a public resource for national decision making. Due to these inherent attributes, statistics are utilized as baseline and base data for government policy determinations and the analysis of various phenomena. However, compared to the importance, the role of statistics is limited, and statistics are often used as simple abstracts, produced mainly for suppliers, not for consumers' perspectives to create value. This study explores the statistical data and other attributes that can be utilized for policies or research to address the problems mentioned above. The baseline statistical data used in this study is from the Maritime Distress Accident Statistical Yearbook published by the South Korean Coast Guard, and other additional attributes are from text analyses of vessel casualty situation reports from the South Korean Maritime Police. Collecting 56 attributes drawn from the text analysis and executing an EDA resulted in 88 attribute unions: 18 attribute unions had a satisfactory significance probability (p-value < .05) and a strong correlation coefficient above 0.7, and 70 attribute unions had a middle correlation. (over 0.4 and under 0.7). Additionally, to utilize the extra attributes discovered from the EDA politically, a keyword analysis for each detailed strategy of the disaster Preparation basic plan was executed, the utilization availability of the attributes was obtained using a matching process of keywords, and the EDA deducted attributes were examined.

• Journal of Korean Society of Rural Planning
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• v.5 no.2 s.10
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• pp.56-65
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• 1999

Recently, new concept and paradigm of 'Environmentally-Friendliness' is taking a growing interest in environmental planning and design. This study is to establish the evaluation model for environmentally-friendliness of 'Tourism Farms' in rural areas by LISREL structural equation model. A questionnaire survey was conducted for deputy manager group and expert group. As the Result of LISREL structural equation model, the environmentally-friendliness of tourism farms is composed of three categories. First, conservation of global environment (Low Impact), second, friendliness to surrounding nature(High Contact), and third, environmental health and amenities (Health & Amenity). Five indicators, such as (1)saving of energy and water resource, (2)reduction and reuse of garbage, (3)natural purification of sewage disposal, (4)utilization of natural energy, (5)campaign and education programs of environmentally-friendliness, were affecting the first category, i.e., conservation of global environment(Low Impact). Friendliness to surrounding nature (High Contact) is affected by 3 indicators, (1)contact to nature and diverse green areas, (2)water intimate & contact areas, (3)natural ecology observation by biotope. Finally, the dimension of environmental health and amenity is affected by 3 indicators, (1)nature affinity by farming experience, (2)environmental-friendliness of soil & crops by organic farming, (3) campaign and education programs of environmentally-friendliness. Total coefficient of determination of the structural equation model by LISREL was 0.897, which showed high explanatory power.