• Journal of the Society of Disaster Information
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• v.13 no.1
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• pp.35-42
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• 2017

In this study, to quantitatively evaluate the strength characteristics of the inflatable liquid used for the recovery of soft ground or partial settlement, the inflatable liquids were prepared by dividing the inflatable capacity and the strength characteristics were analyzed according to the conditions. The experimental group was divided into two groups: relatively high expansion group and low expansion group. The specimens were prepared by controlling the volume of 10 ~ 30% of the maximum expansion volume, and the strength of the specimens were evaluated. The compressive strength of the high expansion group and low expansion group was about 2.1 times.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.3
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• pp.247-256
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• 2011

Purpose : The purpose of this study were to determine whether changes of position might effect the chest expansion and pulmonary function of the 20s men obesity. Methods : Thirty subjects with obesity(M:30, % fat>25.0) and thirty normal subjects(M:30, % fat<24.9) were participated in experiment. Subjects were assessed according to position changes(supine position, $45^{\circ}$ lean sitting position, $90^{\circ}$ sitting position) using chest length(chest length for resting, chest expansion) and pulmonary function (Tidal volume, Inspiratory capacity, Vital capacity, Inspiratory reserve volume, Expiratory reserve volume) by the CardioTouch 3000S(BIONET, USA). Repeated measure ANOVA was used to compare each region data of chest length and pulmonary function according to changes of position with obesity and normal subjects. Results : These findings suggest that the obesity can be appear to low chest expansion and pulmonary function than normal subjects on position method. In comparison of three experimental position, supine position was more low. Conclusion : This study showed position of the obesity appear low chest expansion and function of pulmonary volume than normal subjects, and thus it indicates that the pulmonary function of the obesity will be suggest objective respiratory data through the exercise program.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.828-833
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• 2014

In this paper, the performance characteristics for newly developed ejector refrigeration system, which is that the part of saturated vapor from liquid-vapor separator after ejector expansion process is entrained in ejector, and the saturated liquid flows in the evaporator and compressed with the rest of vapor in separator, is studied. The reasons of the performance improvement of refrigeration system are that the refrigeration capacity is increased due to quality reduction after iso-entropic expansion process by ejector and the compression work is reduced because of the relatively high pressure of vapor refrigerant before compression process. The comparison results of the ejector system entraining expansion gases with the present residential freezer show that the COP increases to 27.8% maximum in case of the pressure drop to 65% of high pressure of freezer, and to 40.1% for 75% pressure drop of refrigerant R401A. The COP improvement rate with 20%~60% pressure lift in diffuser of ejector is only 2.6%~3%.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.40-45
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• 2011

The purpose of research is to understand the characteristics of refrigeration system having a liquid-vapor phase separator after expansion device and precooling heat exchanger. After expansion process of typical refrigerant of freezer, R134a, the cold vapor of the expanded refrigerant mixture is separated in the liquid-vapor separator and introduced in the precooling heat exchanger to enable the liquid refrigerant to be subcooled. The analysis results showed that the increasing rate of refrigeration capacity and COP can be 8.6% and 1.4%, each. The cause of these performance improvements is due to the difference of the slope of saturated vapor and saturated liquid lines in Mollier diagram of refrigerant.

• Journal of Fashion Business
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• v.10 no.6
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• pp.122-130
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• 2006

The purpose of this study is to develop the appropriate brassiere pattern for women. Total of 6 brands with same design and 75A, 80A size brassieres(total 12 brassieres) were compared and analyzed for pattern, cup size and patterns. SPSS 10.1 statistic process was used for data analysis. The outcom of this study is summarized as follows. Total length of brassiere by grade were performed smaller than the standard difference 5cm. For 1/2 front cover length, There were no significant differences between 75 and 80. The reason for lower line of wing is shorter than upper line of wing is because side support is cut side ways considering lower line of wing is sewn more toward front than upper line of wing. Even it is same A cup size most cup related sizes become larger according to underbust comparing with cup capacity, they range from 146.67cc to 172.83cc for same A cups. Among same A cups with difference underbust there was average of 26.16cc differences. For relations of material, sewing technology and expansion rate, all 6 brands had zigzag type sewing for upper line tape. For every 0.3cm height, there were $17{\sim}21$ stitches. When urethane mixture is similar expansion rate is higher while number of 1 inch zigzag are high. For elasticity, zigzag stitch expand side ways for more expansion.

• Geomechanics and Engineering
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• v.37 no.2
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• pp.97-107
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• 2024

The accurate prediction of grouting upward diffusion height is crucial for estimating the bearing capacity of tip-grouted piles. Borehole construction during the installation of bored piles induces soil unloading, resulting in both radial stress loss in the surrounding soil and an impact on grouting fluid diffusion. In this study, a modified model is developed for predicting grout diffusion height. This model incorporates the classical rheological equation of power-law cement grout and the cavity reverse expansion model to account for different degrees of unloading. A series of single-pile tip grouting and static load tests are conducted with varying initial grouting pressures. The test results demonstrate a significant effect of vertical grout diffusion on improving pile lateral friction resistance and bearing capacity. Increasing the grouting pressure leads to an increase in the vertical height of the grout. A comparison between the predicted values using the proposed model and the actual measured results reveals a model error ranging from -12.3% to 8.0%. Parametric analysis shows that grout diffusion height increases with an increase in the degree of unloading, with a more pronounced effect observed at higher grouting pressures. Two case studies are presented to verify the applicability of the proposed model. Field measurements of grout diffusion height correspond to unloading ratios of 0.68 and 0.71, respectively, as predicted by the model. Neglecting the unloading effect would result in a conservative estimate.

• Korean Journal of Materials Research
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• v.34 no.7
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• pp.370-376
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• 2024

In this study, we report significant improvements in lithium-ion battery anodes cost and performance, by fabricating nano porous silicon (Si) particles from Si wafer sludge using the metal-assisted chemical etching (MACE) process. To solve the problem of volume expansion of Si during alloying/de-alloying with lithium ions, a layer was formed through nitric acid treatment, and Ag particles were removed at the same time. This layer acts as a core-shell structure that suppresses Si volume expansion. Additionally, the specific surface area of Si increased by controlling the etching time, which corresponds to the volume expansion of Si, showing a synergistic effect with the core-shell. This development not only contributes to the development of high-capacity anode materials, but also highlights the possibility of reducing manufacturing costs by utilizing waste Si wafer sludge. In addition, this method enhances the capacity retention rate of lithium-ion batteries by up to 38 %, marking a significant step forward in performance improvements.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.5
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• pp.446-475
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• 2000

Performance of a water-to-water multi-type heat pump system using R22 has been experimentally investigated. Total refrigerant flow rate was adjusted with a variable speed compressor and the refrigerant flow rate for two indoor units were controlled by electronic expansion valves. Evaporator outlet pressure of refrigerant and indoor unit outlet temperatures of secondary fluid were selected as controlled variables. Experiments were carried out for both cooling and heating modes using PID control method. Results show that the multi-type heat pump system can be adequately controlled by keeping control gains at certain levels for various operating conditions.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.1
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• pp.115-129
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• 2003

This paper Is concerned with a new techno-economic model Ing of ATM based h19h-speed networks. Coupled with advances of technology, the rapid development of new telecommunication services significantly increases the magnitude of risk in making an Investment decision. Naturally, the success of techno-economic modeling depends on how effectively we manage underlying risk factors such as cost and technology To deal with risk factors, we need to rely on modern decision and risk analysis while Implementing mathematical optimization for solving a complex capacity expansion problem of telecommunication systems during the planning period. We provide a case study that will enhance our understanding of the techno-economic analysis for emerging telecommunication systems.

• Journal of Hydrogen and New Energy
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• v.27 no.4
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• pp.349-356
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• 2016

Volumetric capacity metrics at cryogenic condition are critical for technological and commercial development. It must be calculated and reported in a uniform and consistent manner to allow comparisons among different materials. In this paper, we propose a simple and universal protocol for the determination of volumetric capacity of sorbent materials at cryogenic condition. Usually, the sample container volume containing porous sample at RT can be directly determined by a helium expansion test. At cryogenic temperatures, however, this direct helium expansion test results in inaccurate values of the sample container volume for microporous materials due to a significant helium adsorption, resulting significant errors in hydrogen uptake. For reducing this container volume error, therefore, we introduced and applied the indirect method such as 'volume correction using a non-porous material', showing a reliable cold volume correction.