• Journal of the Society of Disaster Information
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• v.10 no.1
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• pp.15-24
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• 2014

The study presents work information classification system of apartment house which can organize all construction management services throughout the planning and management of a construction such as the decomposition of the design process, the assembly of construction process and cost estimating, etc. In addition, the study suggested a way to connect work information classification system based on a relational database in working order and built a conceptual model for automated cost estimating by utilizing established data base. A conceptual model for automated cost estimating will resolve the fundamental problems of the existing cost estimating system and will be able to take advantage of scientific cost estimating system at the construction site of apartment house.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.3
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• pp.216-222
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• 2005

An experimental investigation was executed to determine the capacity degradation due to fin conduction and non-uniform refrigerant distribution in a multi-path evaporator with cross-counter flow. The finned-tube evaporator, which had a three-path and three-depth-row, was tested by controlling inlet quality, exit pressure, and exit superheat for each refrigerant path. The capacity reduction due to superheat unbalance between each path was as much as $25\%$ for non-cutting evaporator, even when the overall evaporator superheat was kept at a target value of $5.6^{\circ}C$. It indicates that the internal heat transfer within the evaporator assembly causes the partial capacity drop. The capacity of cutting-evaporator with respect to non-cutting evaporator was enhanced according to the increment of air flow rate when superheat or superheat unbalance increased.

• Nuclear Engineering and Technology
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• v.30 no.4
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• pp.342-352
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• 1998

A nuclear design feasibility of soluble boron free(SBF core for the medium-sized(600MWe) PWR was investigated. The result conformed that soluble boron free operation could be performed by using current PWR proven technologies. Westinghouse advanced reactor, AP-600 was chosen as a design prototype. Design modification was applied for the assembly design with burnable poison and control rod absorber material. In order to control excess reactivity, large amount of gadolinia integral burnable poison rods were used and B4C was used as a control rod absorber material. For control of bottom shift axial power shape due to high temperature feedback in SBF core, axial zoning of burnable poison was applied to the fuel assemblies design. The combination of enrichment and rod number zoning for burnable poison could make an excess reactivity swing flat within around 1% and these also led effective control on axial power offset and peak pin power, The safety assessment of the designed core was peformed by the calculation of MTC, FTC and shutdown margin. MTC in designed SBF core was greater around 6 times than one of Ulchin unit 3&4. Utilization of enriched BIO(up to 50w1o) in B4C shutdown control rods provided enough shutdown margin as well as subcriticality at cold refueling condition.

• Nuclear Engineering and Technology
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• v.16 no.4
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• pp.195-201
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• 1984

A state-of-the-art mechanistic model has been developed to accurately predict the void fraction in the subcooled boiling region having axial nonuniform heat flux. In this study, the void-dependent drift-flux parameters of the Lahey/Ohkawa model were introduced and the mass flux-dependent condensation coefficient were determined by fitting with the experimental data. This model was tested against several experimental data sets to verify its accuracy. Finally the comparison between the predicted void fraction profiles with this model and the profile-fit model for the hot assembly of Kori-Unit 1, Cycle 1 has been performed. It is conclusive that the results show the good agreement between the measured and predicted void fractions, and the profile-fit model has been found to underestimate the void fraction in the subcooled boiling region.

• Transactions of Materials Processing
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• v.27 no.1
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• pp.18-27
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• 2018

As one of the functional metal parts in steam turbine diaphragm assembly, the hollow-partitioned turbine nozzle (stator) has large and thick geometries, as well as an asymmetric configuration. Therefore it is hard to support a metal blank in the die cavity. To ease this situation and control posture and position of metal blank (workpiece), a blank support structure is newly introduced. The blank support structure is basically composed of enlarged arms from the blank, guide pins and linear bearings. It can help to control the intermediate blank without a critical sliding phenomenon. The operation mechanism of this blank support structure, during thick plate forming for the hollow-partitioned turbine nozzle stator, is first evaluated. A series of FEM-based numerical simulations, with respect to the width of the guide arm as geometric design parameters, are carried out to investigate its applicable range. As the results, it is observed the blank support structure for this thick plate forming can guide the workpiece to have stable posture during the plate forming process.

• Survey Research
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• v.2 no.1
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• pp.1-35
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• 2001

On the election day of the 16th Korea National Assembly. nationwide TV stations such as KBS. SBS and MBC broadcasted election forecasting based on telephone surveys and exit polls. The result turned out to be significantly wrong. undermining general audience's confidence on the “scientific” surveys. The purpose of this study consists of the followings. i) What form of telephone surveys and exit polls were adopted by survey institutions in real field\ulcorner ii) What were the problems\ulcorner iii) What can we do to make it straight\ulcorner Major findings of the study include the ignorance of call-back rules in telephone survey and the inadequate number of sampled election posts to make satisfactory forecasting. It is pointed out that it is necessary to amend election laws related to election opinion polls to make a substantial progress.

• Journal of Applied Reliability
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• v.11 no.3
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• pp.235-244
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• 2011

Hydraulic hose assemblies deliver a fluid power in various oil pressure equipment such as construction machinery, automobile, aircraft, industrial machinery, machine tools and machinery for ships. Also, they are widely used as pipes in oil pressure circuit. When we estimate their lifetime, it is essential to conduct an accelerated life test by choosing the factor that suits the usage condition of the test object since traditional test method for estimating lifetime under the influence of various external factors incurs hardship in terms of time and expenses. The objective of this study is to propose an acceleration model that takes both temperature and pressure without flexing condition into consideration. The lifetime is estimated by applying the proposed temperature-nonthermal acceleration model to the test data. And we compare the proposed temperature-nonthermal acceleration model and the accelerated life equation suggested by John(1994).

• YAKHAK HOEJI
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• v.53 no.4
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• pp.173-178
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• 2009

This study aimed to analyze the master's and doctoral theses in social pharmacy field over the past 10 years in Korea. Theses were searched based on the Korean National Assembly Digital Library System, and descriptive analyses were conducted using SAS. Among 669 theses, pharmacy/pharmacist accounted for 24.8%, followed by drug misuse with 16.9%, and pharmaceuticals industry related theses with 16.6%. Graduate school of pharmacy was responsible for a share of 27.2%, suggesting that approximately a quarter of the entire social pharmacy related theses are studies at the school of pharmacy.

• Particle and aerosol research
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• v.9 no.2
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• pp.51-57
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• 2013

A graphene(GR)-$TiO_2$ composite was synthesized from colloidal mixture of graphene oxide(GO) nanosheets and $TiO_2$ nanoparticles by an aerosol assisted self-assembly. The morphology, specific surface area and pore size of asprepared GR-$TiO_2$ composite were characterized by FE-SEM, BET, and BJH respectively. The shape of GR-$TiO_2$ composite was spherical. The average particle size was 0.5-1 ${\mu}m$ in diameter and the pore diameter ranged 20-50 nm. Photovoltaic characteristics of a mixture of the GR-$TiO_2$ and $TiO_2$ nanoparticles were measured by a solar simulator under simulated solar light. The highest photoelectric conversion efficiency of the mixture photoanode was 5.1%, which was higher than that of $TiO_2$ photoanode.

• Journal of Radiation Protection and Research
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• v.42 no.1
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• pp.69-76
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• 2017

Background: Time-resolved optically stimulated luminescence (TR-OSL) is a very useful method for calculating the lifetimes of crystalline quartz and feldspar. Materials and Methods: A compact TR-OSL system was developed, comprising a heater assembly manufactured using Kanthal wire, 2 powerful blue light-emitting diodes (LED, LXHL-PB02) for optical stimulation equipped with VIS liquid light guides, and a photomultiplier tube combined with an optical filter for luminescence detection. A pulse generated from the data acquisition board (NI PCI 6250) was used to initiate on/off signals in LED and TR-OSL measurements. Results and Discussion: The TR-OSL and background signals measured using this TR-OSL system using quartz samples were very similar to those reported in a previous study. Additionally, the lifetimes of the build-up and TR-OSL signals were calculated as $27.4{\pm}2.2{\mu}s$ and $30.3{\pm}0.6{\mu}s$, respectively, in good agreement with the findings of a previous study. Conclusion: It was concluded that the developed TR-OSL system was very reliable for TR-OSL signal measurements and lifetime calculations.