• Journal of The Korean Association For Science Education
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• v.14 no.2
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• pp.184-191
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• 1994

In this study, a part of high school science instructional materials is evaluated by Instructional Quality Profile(IQP) based on the Merrill's Component Display Theory(CDT). The CDT is based on the Gagne assumption of different conditions of learning for different outcomes. The IQP enables the user to check both the consistency and adequacy of existing cognitive instruction. The IQP can be used to predict student performance, and also to design and develop new insturctional materials. The instructional components are classified according to 5 task levels; An Use-Generalities on Newly Encountered Examples(UGeg), A Remember-Paraphrased -Generalities (RpG), A Remember-Verbatim-Generalities (RvG), A Remember-Paraphrased -Examples (Rpeg), A Remember-Verbatim-Examples(Rveg). And the instructional presentations are classified according to 4 levels: Explain Generalities(EG), Explain examples(Eeg), Inquiry Generalities(IG), Inquiry examples(Ieg). The instructional presentations are determined by instructional components of a related test item, and indexes of the presentation adequacy are calculated by the instructional presentations. The indexes of this study(0.17 - 0.44) were very low and it indicates that the instructional presentations were not adequate to the instructional components of the related text item.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.1
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• pp.11-18
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• 2020

The emergence of the flow-through cell (FTC) method has made up for the limitations of previous dissolution test methods, but the high cost of the FTC dissolution devices have seriously hindered the progression of research and application of the FTC. This new design uses a peristaltic pump to simulate the sinusoidal flow rate of a piston pump. The flow profile of each peristaltic pump was sinusoidal with a pulsation of 120 ± 1 pulses per minute, and the flow rate ranged from 1.0 - 36.0 mL/min. The flow control of each channel was adjusted independently so the flow errors of the seven channels were close to 2%. The structure of the system was simplified, and the cost was reduced through manual sampling and immersing the FTC in a water bath. The dissolution rate of the theophylline and aminophylline films was determined, and good experimental results were obtained.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.419-426
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• 2004

A three-dimensional computation was conducted to understand effects of the inlet boundary layer thickness on the loss mechanism in a low-speed axial compressor operating at the design condition(${\phi}=85\%$) and near stall condition(${\phi}=65\%$). At the design condition, the flow phenomena such as the tip leakage flow and hub comer stall are similar independent of the inlet boundary layer thickness. However, when the axial compressor is operating at the near stall condition, the large separation on the suction surface near the casing is induced by the tip leakage flow and the boundary layer on the blade for thin inlet boundary layer but the hub corner stall is enlarged for thick inlet boundary layer. These differences of internal flows induced by change of the boundary layer thickness on the casing and hub enable loss distributions of total pressure to be altered. When the axial compressor has thin inlet boundary layer, the total pressure loss is increased at regions near both casing and tip but decreased in the core flow region. In order to analyze effects of inlet boundary layer thickness on total loss in detail, using Denton's loss models, total loss is scrutinized through three major loss categories in a subsonic axial compressor such as profile loss, tip leakage loss and endwall loss.

• Korean Journal of Computational Design and Engineering
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• v.8 no.2
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• pp.115-121
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• 2003

A new Layered Manufacturing(LM) system, named PaperMill, is developed applying micro milling technology. A micro endmill(127 11m in diameter) is introduced as the cutter of build material. The selected build material for this system is an adhesive-coated paper roll which provides advantages such as good bonding between layers, machinability, and low material cost. A 3-axis CNC controller and three step-motors are used for the movement of X-Y-Z table of the system. For simplicity of the control of mechanism, the control system for feeding the paper roll is uncoupled from CNC controller. Two code converters are developed for the toolpath generation of the new LM system. The NC converter generates a set of NC codes for PaperMill using commercial CAM software while the SML converter generates an NC code from Quickslice's SML format. The NC codes generated from the converters consist of a series of profile data and trigger code for paper feeding. Two sample gears were fabricated to prove the concept of the system, which shown that the dimensional errors of the fabricated gears is under 3.4 percent.

• Archives of design research
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• v.19 no.6 s.68
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• pp.15-20
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• 2006

Despite the SKM Duyree shop's potentials, such as residing over the Samsung-dong, gangnam-gu one of the premier locations in Seoul, and offering a large shopping store, the old 'SKM Dutyfree' symbol [image #2] has become the burden for a company due to its low-profile brand quality and lack of location advertisements. Therefore, first, we have agreed to acquire the popular brand word 'COEX' and replace "SKM Dutyfree" to "COEX Dutyfree", and second, the new visual image has been created in order to create a synergy of the urban-look and the location-information. Therefore, the visual identity design concepts have been utilized in order to achieve such goals; first, promote the existing COEX-image and metropolitan-esque image. Second, unify the international-metropolitan looks of the COEX-mall, hotel, shopping center, exhibition, and airport terminal with location information. Third, deliver the new identity-design [image #1] of the fresh look(compare to competing dutyfree shops) and dynamic images.

• Animal Bioscience
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• v.37 no.3
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• pp.500-508
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• 2024

Objective: Due to current selection practices for increased egg production and peak persistency, the production profile, age at maturity, and body weight criteria for commercial layers are constantly changing. Body weight and age at the time of photostimulation will thus always be the factors that need to be adequately addressed among various production systems. The current study was carried out to determine the effects of pullets' body weight (low, medium, and heavy) on their performance, welfare, physiological response, and hormonal profile. Methods: With regard to live weight, 150 16-week-old pullets were divided into three groups using a completely randomized design (CRD) and held until the 50th week. One-way analysis of variance was used to evaluate the data under the CRD, and the least significant difference test was used to distinguish between treatment means. Results: In comparison to the medium and light birds, the heavy birds had higher body weight at maturity, an earlier age at maturity, and higher egg weight, eggshell weight, eggshell thickness, egg yolk index, breaking strength, egg surface area, egg shape index, egg volume, and hormonal profile except corticosterone. However, the medium and light birds had lower feed consumption rates per dozen eggs and per kilogram of egg mass than the heavy birds. Light birds showed greater body weight gain, egg production, and egg specific gravity than the other categories. At 20 weeks of age, physiological response, welfare aspects, and catalase were non-significant; however, at 50 weeks of age, all these factors-aside from catalase-were extremely significant. Conclusion: The findings of this study indicate that layers can function at lower body weights during photostimulation; hence, dietary regimens that result in lighter pullets may be preferable. Additionally, the welfare of the birds was not compromised by the lighter weight group.

• The KSFM Journal of Fluid Machinery
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• v.12 no.3
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• pp.44-52
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• 2009

Small scale steam turbines are used as mechanical drivers in chemical process plant or power generators. In this study, a design technology was developed for a 100kW class steam turbine which will be used for removing $CO_2$ from the emission gas on a reheated cycle system. This turbine is operated at a low inlet total pressure of $5\;kgf/cm^2$. It consists of two stages and operates at the partial admission. For the meanline analysis, a performance prediction method was developed and it was validated through the performances on the operating small steam turbines which are using at plants. Their results showed that the output power was predicted within 10% deviation although the steam turbines adopted in this analysis were operated at different flow conditions and rotor size. The turbine blades was initially designed based on the computed results obtained from the meanline analysis. A supersonic nozzle was designed on the basis of the operating conditions of the turbine, and the first stage rotor was designed using a supersonic blade design method. The stator and second stage rotor was designed using design parameters for the blade profile. Finally, Those blades were iteratively modified from the flow structures obtained from the three-dimensional flow analysis to increase the turbine performance. The turbine rotor system was designed so that it could stably operate by 76% separation margin with tilting pad bearings.

• Nuclear Engineering and Technology
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• v.35 no.4
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• pp.356-368
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• 2003

Material properties such as coolant specific heat, film heat transfer coefficient, cladding thermal conductivity, surface diffusion coefficient of the multi-bubble are improved in MACSIS-Mod1. The axial power and flux profile module was also incorporated with irradiation history. The performance and feasibility of the updated driver fuel pin have been analyzed for nominal parameters based on the conceptual design for the KALIMER breakeven core by MACSIS-MOD1 code. The fuel slug centerline temperature takes the maximum at 700mm from the bottom of the slug in spite of the nearly symmetric axial power distribution. The cladding mid-wall and coolant temperatures take the maximum at the top of the pin. Temperature of the fuel slug surface over the entire irradiation life is much lower than the fuel-clad eutectic reaction temperature. The fission gas release of the driver fuel pin at the end of life is predicted to be $68.61\%$ and plenum pressure is too low to cause cladding yielding. The probability that the fuel pin would fail is estimated to be much less than that allowed in the design criteria. The maximum radial deformation of the fuel pin is $1.93\%$, satisfying the preliminary design criterion ($3\%$) for fuel pin deformation. Therefore the conceptual design parameters of the driver fuel pin for the KALIMER breakeven core are expected to satisfy the preliminary criteria on temperature, fluence limit, deformation limit etc.

• Journal of Korea Foundry Society
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• v.12 no.3
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• pp.220-229
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• 1992

The degree of purification and the macrostructure of high purity aluminium were studied through the alternate stirring method in order to improve the nonuniformity of solute concentration in the unidirectional stirring method. The $2^3$ factorial design was done to examine the effects of experimental factors more qualitatively. In the relatively low stirring speed of 1500 rpm with alternate stirring mode, the uniform solute profile and refined grain structure were obtained due to strong washing effect and turbulent fluid flow. It was induced by the transition of the momentum boundary layer by alternation of the stirrer. It was concluded from this study that the alternate stirring mode was more effective to obtain the uniformity of solute even in the stirring speed of 1500 rpm. But the degree of purification decreased below the critical alternating period. When 2N(99.8wt.%) aluminium was used as the starting material the morphology of solid-liquid showed the cellular shape and the columnar grains were inclined to the direction of rotation. This inclined grain growth resulted from the difference of relative velocities of solid and liquid. The inclined angle was increased as the stirring speed increased and solidification proceeded. In the case of 4N aluminium, there was no inclined grain growth and it was confirmed from the macrostructure and SEM work that the morphology of solid-liquid interface was planar. From the factorial design, it was found that the alternate stirring mode showed poorer purification effect than that of unidirectional stirring mode at low speed(500 rpm). In addition, the factor that had the most significant effect on the degree of purification was the stirring speed.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1098-1106
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• 2004

In a split-unit design, 12 Javan rusa (Cervus timorensis russa) stags (6 castrated and 6 entire) were used to investigate seasonal (winter, spring and summer) effects on intake, digestibility of food constituents, volatile fatty acid profile, and nitrogen retention, when given lucerne (Medicago sativa) or rhodes grass (Chloris guyana) hays. Entire stags ate 9% more dry matter (DM) than castrates (p<0.05). Both castrated and entire stags exhibited seasonal changes in DM intake, these being higher (p<0.05) in winter (62.3 g/kg $W^{0.75}$) than spring (56.9 g/kg $W^{0.75}$) or summer (55.3 g/kg $W^{0.75}$). Intakes of lucerne hay (211 g protein/kg DM) were significantly higher than of rhodes grass hay (49 g protein/kg DM) in all seasons (p<0.05). Digestibilities of DM (0.58), neutral detergent fibre (0.59) and acid detergent fibre (0.47) were similar between castrates and entires. DM digestibility was higher (p<0.0001) for lucerne (0.66) than rhodes grass (0.55), and was higher (p<0.05) in winter (0.60) than spring (0.58) or summer (0.57). The ruminal acetate concentrations were higher (p<0.001) in spring than summer (78 and 73 molar % respectively). Apparent digestibility of protein was significantly less (p<0.0001) for rhodes grass (0.37) than lucerne (0.75). N retention was positive for lucerne (15.2 g/d) but negative for rhodes grass (-2.8 g/d) (p<0.0001), and was higher (p<0.001) in summer (12.0 g/d) than spring (4.3 g/d) or winter (2.4 g/d). The tropical rusa deer exhibits seasonal variations in feed intake, food constituent digestibilities, VFA profile and N retention. Castration did not alter these traits. The results do not support the view that rusa deer can thrive on low-quality pastures. The productivity and commercial exploitation of rusa deer could be optimised if they are given high-protein feed during spring and summer.