• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.14-24
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• 2006

To develop small-scale sewage treatment apparatus for detached house of agricultural village, a small-scale sewage treatment apparatus by natural purification method that consisted of aerobic and anaerobic bed was constructed. To reduce the area of a sewage treatment apparatus, four different fitter media were used and each filter medium was coarse sand, broken stone, steel slag, and mixed fitter media (coarse sand : broken stone : steel slag = 1:1:1). The efficiency of sewage treatment according to the depth of aerobic and anaerobic bed and the volume ratio of aerobic to anaerobic bed were investigated in small-scale sewage treatment apparatus. The removal rate of pollutants according to the depth of aerobic and anaerobic bed in small-scale sewage treatment apparatus was high in the order of 50 cm < 70 cm < 90 cm. The removal rate of pollutants according to the ratio of aerobic to anaerobic bed in small-scale sewage treatment apparatus was high in the order of 1:1 < 1:2 $\fallingdotseq$ 1:3. Under the optimum conditions, removal rate of BOD, COD, SS, T-N and T-P were $98{\sim}99,\;95{\sim}97,\;99,\;65{\sim}66\;and\;96{\sim}99%$ respectively, in small-scale sewage treatment apparatus.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.28-31
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• 2009

In this paper, a new approach for solid texture synthesis from input volume data is presented. In the pre-process, feature vectors and a similarity set were constructed for input volume data. The feature vectors were used to construct neighboring vectors for more accurate neighborhood matching. The similarity set which recorded 3 candidates for each voxel helped more effective neighborhood matching. In the synthesis process, the pyramid synthesis method was used to synthesize solid textures from coarse to fine level. The results of the proposed approach were satisfactory.

• Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.242-249
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• 1998

The engineering aspect of water treatment processes in the recirculating aquaculture system was studied. To recycle the water in the aquaculture system, a wastewater treatment process was required to maintain high water quality for the growth and health of the cultured fish. In this study, three different biofilm processes were used to reduce the concentration of organic matters and ammonia from the recirculating water - two phase fluidized bed, three phase fluidized bed, and trickling filter. The objectives of this research were to evaluate the optimum treatment conditions of the biofilm processes for the recirculating aquaculture system, and thereby reduce the volume of biofilm processes, which are commonly used for the recycle water treatment processes for aquaculture. The result of this study showed that the removal efficiency of organic matters by trickling filter was found to be lower than that of the fluidized bed. In the trickling filter system, anthracite showed better organic removal efficiency than crushed stone as a media. In the two phase fluidized bed, the maximum removal efficiency of either organics or ammonia was obtained when both the packing rate of media was maintained to $40\%$ of total reactor depth excepting sediment zone and the bed expansion rate was maintained to $100\%$. When 100 tilapia (Oreochromis niloticus) of each average 200g was reared, the pollutant production rate was 0.07g $NH_4\;^+-N/kg$ fish/day and 0.06g P04-3-P/kg fish/day, and sludge production rate was 0.39 g SS/kg fish/day. In the two phase and three phase fluidized bed, the volume of water treatment tank could be calculated from an empirical equation by using the relationship between the influent COD to $NH_4\;^+-N$ ratio (C/N, -), media concentration (Cm, g/L), influent ammonia nitrogen concentration (Ni, mg/L), effluent ammonia nitrogen concentration (Ne, mg/L), bed expansion rate $(E,\;\%)$, and influent flowrate $(Q,\;m^3/hr)$. The empirical equation from this study is $$V_2\;=\;10^{3.1279}\;C/N^{3.5461}\;C_m\;^{-3.7473}\;N_i\;^{4.6477}\;E^{0.0326}\;N_e\;^{-0..8849}\;Q\;(Two\;Phase\;FB) V_3\;=\;10^{11.7507}\;C/N^{-1.2330}\;C_m\;^{-6.5715}\;N_i\;^{1.5091}\;N_e\;^{-1.8489}\;Q (Three\;Phase\;FB)$$

• Korean Institute of Interior Design Journal
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• v.22 no.5
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• pp.293-301
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• 2013

The purpose of this study was to find the space perception by the scene and to analyze the characteristics in the exhibition space. The data for the analysis was collected through a questionnaire survey method. The questionnaire is composed of a scene selection on the panoramic photographs of the exhibition space. 'The 4 Rivers Cultural Center - The ARK' was selected as the subject of this survey. The results of the study are presented as follows : First, the space perception perceived imaged scenes rather than the specific elements of space. Second, the space perception was revealed through the 'Form', 'Materials', 'Light', 'Lighting', 'Furniture' and 'Media' of notable elements. Also that was perceived by forming 'Line', 'Surface' and 'Volume'. Particularly, the perception of 'Surface' was higher than 'Line' and 'Volume'. 'Surface' was perceived mostly through the 'Color'. The perception of 'Line' was positive to 'Boundary' or 'Continuous placement of the light'. In addition, the perception of 'Volume' was positive to 'The curve of the form', 'Transparent material', 'Three-dimensional elements'. Finally, The type of space perception was chosen as 'Extension', 'Center', 'Deep', 'Boundary' and 'Formative'. In this way, the results of this study will set a foundation for developing design methods to induce the space perception by the scene in the exhibition space.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2476-2481
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• 2007

An inverse radiation analysis is presented for the estimation of the wall emissivities for an absorbing, emitting, and scattering media with diffusely emitting and reflecting opaque boundaries. In this study, a repulsive particle swarm optimization(RPSO) algorithm which is a relatively recent heuristic search method is proposed as an effective method for improving the search efficiency for unknown parameters. To verify the performance of the proposed RPSO algorithm, it is compared with a basic particle swarm optimization(PSO) algorithm and a hybrid genetic algorithm(HGA) for the inverse radiation problem with estimating the wall emissivities in a two-dimensional irregular medium when the measured temperatures are given at only four data positions. A finite-volume method is applied to solve the radiative transfer equation of a direct problem to obtain measured temperatures.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1639-1644
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• 2003

A hybrid genetic algorithm is developed for estimating the wall emissivities for an absorbing, emitting, and scattering media in a two-dimensional irregular geometry with diffusely emitting and reflecting opaque boundaries by minimizing an objective function, which is expressed by the sum of square errors between estimated and measured temperatures at only four data positions. The finite-volume method was employed to solve the radiative transfer equation for a two-dimensional irregular geometry. The results show that a developed hybrid genetic algorithms reduce the effect of genetic parameters on the performance of genetic algorithm and that the wall emissivities are estimated accurately without measurement errors.

• Journal of applied mathematics & informatics
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• v.11 no.1_2
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• pp.215-241
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• 2003

In this paper, solute transport in heterogeneous aquifers using a modified Fokker-Planck equation (MFPE) is investigated. This newly developed mathematical model is characterised with a time-, scale-dependent dispersivity. A two-dimensional finite volume quadrilateral mesh method (FVQMM) based on a quadrilateral background interpolation mesh is developed for analysing the model. The FVQMM transforms the coupled non-linear partial differential equations into a system of differential equations, which is solved using backward differentiation formulae of order one through five in order to advance the solution in time. Three examples are presented to demonstrate the model verification and utility. Henry's classic benchmark problem is used to show that the MFPE captures significant features of transport phenomena in heterogeneous porous media including enhanced transport of salt in the upper layer due to its parameters that represent the dependence of transport processes on scale and time. The time and scale effects are investigated. Numerical results are compared with published results on the some problems.

• Asia-Pacific Journal of Business
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• v.14 no.4
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• pp.37-48
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• 2023

Purpose - This study aims to explore the influence of emotional discrepancies among investors on the cryptocurrency market. It focuses on how varying emotions affect market dynamics such as volatility and trading volume in the context of Bitcoin trading. Design/methodology/approach - This study involves analyzing data from Bitcointalk.org, consisting of 57,963 posts and 2,215,776 responses from November 22, 2009, to December 31, 2022. Tools used include the Linguistic Inquiry and Word Count (LIWC) software for classifying emotional content and the Python Pattern library for sentiment analysis. Findings - The results show that heterogeneous emotional feedback, whether positive or negative, significantly influences Bitcoin's intraday volatility, skewness, and trading volume. These findings are more pronounced when the underlying emotion in the feedback is amplified. Research implications or Originality - This study underscores the significance of emotional factors in financial decision-making, especially within the realm of social media. It suggests that investors and market strategists should consider the emotional landscape of online forums when making investment choices or formulating market strategies. The research also paves the way for future studies regarding the behavioral impact of emotions on the cryptocurrency market.

• ETRI Journal
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• v.32 no.6
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• pp.940-949
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• 2010

Rack-level DC power supply is the optimal technology for providing DC power to a volume server without any power infrastructure changes in an existing AC data center. In this paper, we propose a smartly controllable and monitorable DC rack power system. The proposed system improves power efficiency by changing the power distribution architecture of a conventional method in the rack. We developed an optimal power control method in multipower modules to provide high efficiency at low loads. In addition, the proposed system provides real-time web monitoring of the rack power and environment around a rack. In our experiments, the proposed system improved the power efficiency by over 10% compared to an AC power system providing N+1 redundant power and power monitoring.

• Journal of the Korean Operations Research and Management Science Society
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• v.14 no.1
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• pp.107-107
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• 1989

Demand for new information services is ever increasing as information technology advances in an unprecedented pace. Capabilities of information technology to overcome the time and space limitations enables efficient storage and processing of a large volume of data shared by many users in geographically dispersed areas. As the users ask for more useful information services, it is necessary to develop information services tp meet the needs of users. Enhancing information services is also necessary to cope actively with the pressures to open the information service is also necessary to cope actively with the pressures to open the information and telecommunications market as the level of Korean information services industry is still in its infancy. Value Added Network(VAN) services have a tremendous growth potential and its economic and social impact would be great as the information society matures. This study suggests a direction for the development of value added and new-media services based on the survey of individual and business users of information services.