• Journal of the Korean housing association
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• v.13 no.6
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• pp.89-99
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• 2002

The purpose of this research is to analyze the characteristics of flow rate distribution in hot-water piping networks in the apartment building. A 14-story apartment house was selected as a sample building and analyzed numerically by Hardy-Cross method. Two different piping networks, one has three vertical zones and the other of a single zone with automatic balancing valves, were compared. Some of research results are as follows; As the temperature of supply hot-water increases, the flow rate of it does by buoyancy effect, but this effect is not found in the piping network with automatic balancing valves. Non-uniformity in hot-water flow distributions to all stories in the piping system of single vertical zone can be completely reformed by the installation of either manually operated or automatic balancing valves in every story.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.286_287
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• 2009

In this paper, the protectability of distance relay is furtherly researched. Based on the probabilistic modeling of the measurement errors, the protectability of three zones is presented in detail by considering their different protection aims denoted by sensitivity and selectivity. The optimal setting for the each zone can be obtained to provide a reference for the practical application.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.129-132
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• 2000

In this research, we proposed the immobilization zone where the organic contaminant would be fixed, so that ground water could be prevented from the organic contaminants. The surfactant was adsorbed on the soil particles and the organic contaminants were partitioned into the hydrophobic tails of the surfactant in the immobilization zone. Surfactants with different molecular structures-SDDBS (sodium dodecylbenzenesulfonic acid), MADS (monoalkylated disulfonated diphenyl oxide), DADS (dialkylated disulfonated diphenyl oxide) - were used in this study. Up to the present, the research on the immolization simulated the saturated condition. But many site contaminated with organic contaminants and the zones where immobilization would be applied are unsaturated. In this research, in order to investigate the behaviors of surfactants and organic contaminants in unsaturated condition, the unsaturated columns were experimented, and their results were compared with the saturated case.

• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.1
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• pp.37-44
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• 2007

A study was made of the haemolymph protein spectrum of mulberry silkworm (Bomhyx mori L.) from the first larval instar to imago. Horizontal starch gel electrophoresis was used. Sixteen races and eight F1 interracial hybrids, raised in Bulgaria, were analyzed. During the ontogenesis, a total of 17 protein bands (15 cathodic and 2 anodic) were detected. Distinct dynamics in the haemolymph protein spectrum was observed, in result of different expression during the individual development associated with the processes of growth, histolysis and histogenesis. Based on the ontogenetic dynamics found, a correspondence was assumed between some proteins detected by us using the starch gel electrophoresis and major haemolymph proteins (SP1, SP2, MHPs and Vg) detected by other authors using the polyacrilamide gel electrophoresis. Intraracial and interracial polymorphism was observed in four protein zones. The effect of four polymorphic loci with codominant and null alleles was suggested.

• Environmental Engineering Research
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• v.23 no.2
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• pp.121-128
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• 2018

This paper describes the non-isothermal pyrolysis of cashew shell cake (CSC) - bituminous coal blends. The blends exhibit two distinct stages in the thermogravimetric curves, which the first stage stems from CSC and the second one from the superposition of CSC and coal pyrolysis. The pyrolysis behavior of the blend was linearly proportional to the blending ratios. The overall behavior of the blends was evaluated in terms of the maximum rate of weight loss, characteristic temperatures, char yields, and the calculated and experimental thermogravimetric curves. The activation energies ranged up to 49 kJ/mol for the blends were obtained and used to evaluate the interaction in the blends. The present thermogravimetric study shows that there is no significant interaction between CSC and coal in the blends, and it was supported by the characteristic values which are linearly proportional to the weight percentages of cashew cake-shell in the blends. The no-interaction might be due to the fact that the main reaction zones are distinctively different for two constituents, so the additive rule is acceptable for describing pyrolysis behavior of the present blends.

• Advances in concrete construction
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• v.10 no.4
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• pp.333-343
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• 2020

In the architectural design process, the selection and configuration of the structural system significantly affect the earthquake behaviours of the reinforced concrete buildings. The main purpose of this study, the effects on the earthquake performances and the rough construction cost of the buildings of the slab type in reinforced concrete buildings are to examine comparatively for different local soil classes. The results obtained from this study have been determined that the building model having slabs with beams is safer compared to other types of slabs, especially when considering the vertical bearing structural elements (columns). It also shows that other types of slab, except for slab with beams, reduce the earthquake performances of reinforced concrete buildings, increase the displacement values, 1st natural vibration period values and the cost of rough construction. This matter reveals that slab type is quite important and the preference of beamed slabs in reinforced concrete buildings to be constructed in earthquake zones would be more appropriate in terms of safety and cost.

• Structural Engineering and Mechanics
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• v.68 no.1
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• pp.81-94
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• 2018

This paper uses the finite element method (FEM) considering geometrically nonlinear strains to study the first ply failure of laminated composite skewed hypar shell roofs through well-established failure criteria along with the serviceability criterion of deflection. Apart from validating the approach through solution of benchmark problems, skewed hypars with different practical parametric variations are studied for failure loads and tendencies. First ply failure zones are also identified to suggest design and non-destructive monitoring guidelines to the practising engineers. Recommendation tables regarding the design approaches to be adopted in specific cases and factor of safety values needed to be imposed on first ply failure load values for varying shell curvatures are also suggested in this paper. Providing practical inputs to design engineers is the main achievement of the present study.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.9
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• pp.793-797
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• 2005

This study introduces Electro-chemical Mechanical Deposition(ECMD) lot making Cu interconnect. ECMD is a novel technique that has ability to deposit planar conductive films on non-planar substrate surfaces. Technique involves electrochemical deposition(ECD) and mechanical sweeping of the substrate surface Preferential deposition into the cavities on the substrate surface nay be achieved through two difference mechanisms. The first mechanism is more chemical and essential. It involves enhancing deposition into the cavities where mechanical sweeping does not reach. The second mechanism involves reducing deposition onto surface that is swept. In this study, we demonstrate ECMD process and characteristic. We proceeded this experiment by changing of distribution of current density on divided water area zones and use different pad types.

• Journal of Welding and Joining
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• v.14 no.2
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• pp.90-95
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• 1996

In order to investigate characteristics of surface fatigue crack propagation from a pit shaped surface defect which frequently exists around welded joints, SS400 steel with thickness of 12mm, which has been generally used for structure members, was welded with submerged-arc butt type and machined for both surface. An initial surface defect of pit shape with the aspect ratio of 2 was made on the specimen. The initial defect was located at 5 different zones over the weldment : weld metal zone, boundary between weld metal and HAZ, HAZ, boundary between HAZ and base metal. Characteristics of surface fatigue crack propagation from the defect on each region under the same loading condition were investigated and compared.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.53.3-54
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• 2016

We combine a semi-analytic model of galaxy evolution with constraints on circumstellar habitable zones and the distribution of terrestrial planets in order to probe the suitability of galaxies of different mass and type to host habitable planets, and how it evolves with time. We find that the fraction of stars with terrestrial planets in their habitable zone (known as habitability) depends only weakly on galaxy mass, with a maximum around $4{\times}10^{10}M_{\odot}$. We estimate that 0.7% of all stars in Milky Way-type galaxies to host a terrestrial planet within their habitable zone, consistent with the value derived from Kepler observations. On the other hand, the habitability of passive galaxies is slightly but systematically higher, unless we assume an unrealistically high sensitivity of planets to supernovae. We find that the overall habitability of galaxies has not changed significantly in the last ~8 Gyr, with most of the habitable planets in local disk galaxies having formed ~1.5 Gyr before our own solar system. Finally, we expect that ${\sim}1.4{\times}10^9$ planets similar to present-day Earth have existed so far in our galaxy.