• Korean Journal of Materials Research
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• v.24 no.1
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• pp.25-32
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• 2014

In this study, nano-sized cobalt oxide powder with an average particle size below 50 nm was prepared from a cobalt chloride solution by the spray pyrolysis process. The influences of reaction temperature on the properties of the generated powder were examined. The average particle size of the particles formed based on the spray pyrolysis process at a reaction temperature of $700^{\circ}C$ is roughly 20 nm. Moreover, most of these particles cannot appear with an independent type, thereby coexisting in a droplet type. When the reaction temperature increases to $800^{\circ}C$, the average particle size not only increases to roughly 40 nm but also shows a more dense structure while the ratio of particles which shows a polygonal form significantly increases. As the reaction temperature increases to $900^{\circ}C$, the distribution of the particles is from roughly 70 nm to 100 nm, while most of the particle surface is more intricately close and forms a polygonal shape. When the reaction temperature increases to $1000^{\circ}C$, the particle size distribution of the powder shows an existing form from 80 nm to at least 150 nm in an uneven form. As the reaction temperature increases, the XRD peak intensity gradually increases, yet the specific surface area gradually decreases.

• Journal of Fashion Business
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• v.12 no.3
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• pp.136-152
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• 2008

The purpose of this study was to provide dress forms and jacket blocks for adult males based on the analysis of their somatotypes. As the result of the research conducted for this study that was based on 1290 males of 20 to 54 years-old, the shapes of adult male were 20 and each body shape was classified by size factor, height and chest girth. Also, master sizes were selected considering appearance frequency. XS type (master size: height 165cm and chest circumference 88cm), Yd type (master size: height 170cm and chest circumference 91cm), YI and AD2 types (master size: height 170cm and chest circumference 94cm) were selected to develop dress forms and their jacket blocks in this study. The procedure and results were follows; 1. The dress forms of XS, Yd, YI and AD2 types were produced base on means of 61 body measurements and cross sections of shoulder, chest, waist, hip of subjects belong to each somatotype. 2. New jacket blocks for XS, Yd, YI and AD2 types were developed based on the body surface developments through draping and the results of comparative investigation on the existing jacket blocks by wearing test. Also the drafting methods of new jacket blocks were provided. 3. The sensory evaluation by wearing test showed that the developed jacket blocks were estimated more highly in terms of chest's allowance, the front width's allowance, neck wrinkle, front allowance and overall appearance's fitness items than existing jacket blocks.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.9-14
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• 2011

The flow rate analysis for sanitary fixtures has been studied to determine the water supply piping system and size. The study has been carried out to analyze for a various water supply pressure and piping size theoretically. Also, the study has been carried out to analyze for a various water supply piping system experimentally. The water supply pressure is varied from 0.01MPa to 0.07MPa, and the piping size is varied from 6mm to 15mm. The water supply piping systems are one-to-one, all-loop-type, and bathroom-loop-type water supply piping system. The results indicate that the piping size is able to supply water fully in case of smaller than 15mm if the water supply pressure keep an necessary minimum pressure. And the gap of flow rate is very little for the various water supply piping systems.

• The Journal of the Acoustical Society of Korea
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• v.26 no.2
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• pp.69-74
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• 2007

In signal processing applications with highly correlated input signals, subband affine projection algorithm and step size controlling is a good solution for improving the slow convergence rate and large computational complexity of LMS-type algorithms. This paper proposes a subband affine projection algorithm using a variable step size. The proposed method achieves fast convergence rate and small steady-state error with a small computational complexity by combining the SAP and step size controlling in a subband structure. Experimental results on highly correlated input signal show that the proposed method is superior to the conventional methods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.332-335
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• 2005

The three Korean wheat cultivars with different plant types; the erect, the middle and the creeping growth habit, were studied for their utilization to solar radiation, temperature changes on the furrow and to provide optimum planting space for producing the high yield in 2003. The average solar radiation rate was lowest for creeping type ($39.2\%$) and highest for erect type ($75.8\%$) The correlation coefficient between the coverage rate and the solar transmission rate was r = 0.8624 which was significant at $5\%$ level. The relative growth of the plant, tiller rate and leaf size was increased in the erect and the middle type at lower plant density, while no change on plant growth at creeping type regardless of plant density. The increase of leaf size in the lower plant density was due to longer flag and the first leaf than those of other plant types. The temperature on the furrow of growing plants was changed by the canopy. The changes in temperature pattern on the furrow according to plant types during winter season was different compared to the non plant ground. The temperature of the nonplant ground was the lowest due to solar reduction increasing the amount of cool air flowing in the furrow.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.7
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• pp.15-23
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• 1999

With a remarkable expansion of communication industry, a pager or a cellular phone becomes a necessary communication device in modern society. However, a paging signal by a buzzer is often acted as an unpleasant noise in some places, thus necessitating a paging signal by a vibration motor. In this paper, a simpler type of a vibration motor, a coreless permanent magnet(PM) DC motor, is considered to substitute for the conventional vibration motors. Using an analytical method, electromagnetic field and operating torque were calculated for the given inner and outer PM type motors, and the results were confirmed by FEM analysis. As design parameters, number of PM poles, PM radial thickness, coil arc angle and number of winding stacks were chosen for sensitivity analysis. It shows that coil arc angle is the most important design parameter to increase the motor performance, without giving an adverse effect on motor weight, size and manufacturing cost. Based on the analysis of the outer PM type motor, an outer square PM type motor is proposed as the final design. Compared to the outer PM type, outer square type provides more flexibility to attach to the small size cellular phones. With the optimum design of square outer PM DC motor, it can successfully substitute the conventional types with less expensive manufacturing cost. better performance and smaller necessary space.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.5
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• pp.869-875
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• 2007

Magnetic properties of electrical steel are, in general. measured by using Epstein frame or single sheet tester (SST). These methods, however, require very strict regulation of a specimen in its size and shape. thus, can not be easily applied to various types of specimen. On the other hand, a ring-test method, which measures only the isotropic properties, can be easily applied to most cases because it requires a toroidal-type specimen of arbitrary size. This method, especially, is considered as an unique available method for a bulk-type specimen. In this paper, a ring-test method is developed, and applied to the measurement of magnetic properties of a bulk-type electrical steel with a toroidal-type specimen. In the measurement, the magnetic properties and iron losses are measured and compared with each other at the both sinusoidal magnetic flux density and sinusoidal magnetic field intensity conditions under 0.2Hz and 60Hz alternating magnetic fields excitation. Through experimental measurements, a sinusoidal magnetic flux density condition is proven appropriate for the measurement of magnetic properties, including iron loss characteristics, of electrical steels.

• The Research Journal of the Costume Culture
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• v.13 no.1
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• pp.6-17
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• 2005

The purpose of this research is to define low body shapes of Plus-sized women at ages between 21 and 69 whose satisfied the Plus-sized judgment criteria took part in this study. This research also classifies different body types, and provides basic data for designing skirt's and slacks' prototypes according to each body type. Based on factor analysis of the measured data, seven key factors are grouped. And four different body types are classified based on the cluster analysis using factor marks. Type 1 refers to those who are tall in stature and balanced. This body type is characterized by trapezoid body shape when looked from the front, and slim the abdomen, bulge the belly and flat the buttocks when looked from the side. Type 2 refers to short and an obese body shapes, with trapezoid front and bulge abdomen and belly and flat the buttocks. Type 3 refers to those who are of medium height and long-legged body shapes, with rectangular front, protruding belly and buttocks. Type 4 refers to obese body shapes, with rectangular front, protruding abdomen and belly, flat the buttocks. 9 items are available to judge Plus-sized women's low body types and the hit ratio is 93.5%.

• Journal of Biosystems Engineering
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• v.19 no.4
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• pp.343-357
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• 1994

Current commercial dairy feed has various problems in low feed productivity, inadequate formulation and higher feeding cost due to excessive capital investment and non-specialized system for the end product. To solve those problems, 6 TMR terminal models were developed in this study. The developed TMR terminal system consists of TMR terminal, TMR main center and combined system linked TMR terminal and TMR main center. 15 TMR main center models were developed to support 10, 20, 30, 40, 50 TMR terminal(30 ton/day basis) by 3 different types, and evaluated for capital investment and operation cost by the analysis of the newly developed computer program. Optimum model size is analyzed and suggested for each model. Followings are summary of this study : 1. The capital investment costs of TMR main centers were 1,600 to 3,800 million won for type 1, 2,200 to 4,500 million won for type 2 and 2,200 to 4,800 million won for type 3. Also model MACE30 or bigger were justified as the economical models. 2. The feed production costs of TMR main center models were 3,166 to 4,824 won/ton for type 1, 3,816 to 6,182 won/ton for type 2 and 3,990 to 6,263 won/ton for type 3. So feed production cost range was 3,166 to 6,263 won/ton. 3. The bigger production capacity, the less TMR main center production cost. The feed production cost of the biggest model MACE50 was 62~65% of smallest model MACE10.

• Journal of Power System Engineering
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• v.18 no.3
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• pp.59-65
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• 2014

The computational fluid dynamics was carried out to evaluate turbulent models on the swirling flow of a gun-type gas burner(GTGB) according to the mesh size. The commercial SC/Tetra software was used for a steady-state, incompressible and three-dimensional numerical analysis. In consequence, the velocity magnitude from the exit of a GTGB and the flowrate predicted by the turbulent models of MP k-${\varepsilon}$, Realizable k-${\varepsilon}$ and RNG k-${\varepsilon}$ agree with the results measured by an experiment very well. Moreover, the turbulent kinetic energy predicted by the turbulent model of standard k-${\varepsilon}$ with mesh type C only agrees with the experimental result very well along the radial distance. On the other hand, the detailed prediction of the information of swirling flow field near the exit of a GTGB at least needs a CFD analysis using a fairly large-sized mesh such as a mesh type C.