• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.85-88
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• 1995

Recently, the micro mold maching techining technology is developed by means of the mechanical and high energy beam process. It is possible to make the micro structure mold with high aspect ratio by the LIGA technology. This mode is used for mass production of plastic parts by the micro injection molding method. In this study, we intend to research on the basic technology of micro injection molding. As the result, we developed the injection molding technology for small column plastic parts which diameter is 500 .mu. m and 200 .mu. m respectively with wbout aspect ratio 20.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2007.10b
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• pp.127-132
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• 2007

Geomancy(風水, Fengshui in Chinese) is a geographic idea of the Orient that studies a piece of land(a site) to pursue the healthier and more comfortable life for people seeking a harmony with nature, and also, a practical science. Among the theoretical systems of the traditional geomancy handed down by the scriptures, the compass school(理氣論) makes researches into mountains, winds, the currents and amount of water circulation by using luo-pan(羅盤) for finding spot(穴), and it has been considered that it is the objective and logical analysis system of natural environment of selecting a good site by dividing the vitality of the ground into 12 levels of natural circulation principles and judging its direction by means of 88-direction method. In this context, researcher optimized the logic of 88-direction method by the 12-circulation system(胞胎法) of the compass school on the basis of directional theory, then after, using GIS analytical tool, researcher performed comparative analysis between the results from land suitability analysis of the subject site and the resulting value of the directional method in geomancy. The results therefrom indicated that more flexible directions and site could be chosen by applying 88-direction method. For the future research, it is required to apply wider variety of variables to the field study and more careful review of the case study with a focus on the 88-directiont method.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.9
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• pp.871-876
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• 2011

In this paper, the equilibrium flight conditions of a Korean Traditional Bangpae Kite with low aspect ratio were analyzed by it's aerodynamic data of wind tunnel test. The data of aerodynamic forces and center of pressure of the Kite were used to calculate the relative length of bridles to satisfy the condition of settling the kite to the static equilibrium steady state between ${\theta}=30^{\circ}{\sim}60^{\circ}$. From this equilibrium flight performance analysis, we obtained ($0.88{\pm}0.02$)c of the rear bridle length corresponding to 0.88c of fixed front bridle length. These results were exact agreement with the relative bridle lengths by Korean classical method.

• Journal of the Korean Society of Propulsion Engineers
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• v.7 no.4
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• pp.39-45
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• 2003

Of the various means for active trajectory correction, a thrust vector control system represents the only principle independent of missile external forces so that this method is operative. The purpose of this study is to analyze the characteristic of jet vane TVC(Thrust vector control) system among mechanical jet deflection. To ensure high performance leading edge shape, aspect ratio and ablated condition is optimized. Supersonic flow system, jet vanes and nozzle with Mach number 2.88 and under expansion ratio 2 were designed to study aerodynamic characteristics of leading edge shape, aspect ratio and ablated conditions.

• Journal of Sensor Science and Technology
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• v.22 no.2
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• pp.136-143
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• 2013

In the study, novel blood pressure estimation method was proposed to improve the accuracy of oscillometric method. The proposed algorithm estimated the blood pressure by comparing and analyzing the point variation aspect of dicrotic notch on pulsating waveform during each cardiac cycle. The waveforms of each cardiac cycle were extracted by maximum points. The extracted pulsating waveforms were applied by re-sampling, end-matching, and normalization. The systolic and diastolic blood pressures were estimated by point variation aspect of dicrotic notch. The blood pressures, which were estimated from proposed algorithm, were compared and analyzed by blood pressures from oscillometric methods and auscultation. The systolic blood pressure from oscillometric methods were +0.88 mmHg more than proposed algorithm, and 1.875 less than the diastolic blood pressures from proposed algorithm. The systolic and diastolic blood pressures from auscultation were 2.89 mmHg and 3.44 mmHg less than the blood pressures from proposed algorithm. As the errors between blood pressures from proposed algorithm, oscillometric method and auscultation were less than 5 mmHg, the proposed algorithm was effective.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.1
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• pp.79-88
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• 2015

This study numerically examined the mixing characteristics of rectangular cavity flows by using the hybrid lattice Boltzmann method (HLBM) applied to the finite difference method (FDM). Multi-relaxation time was used along with a passive scalar method which assumes that two substances have the same mass and that there is no interaction. First, we studied numerical results such as the stream function, position of vortices, and velocity profile for a square cavity and rectangular cavity with an aspect ratio of 2. The data were compared with previous numerical results that have been proven to be reliable. We also studied the mixing characteristics of a rectangular cavity flow such as the concentration profile and average Sherwood number at various Pe numbers and aspect ratios.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.3
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• pp.37-43
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• 2001

The bleach efficiency between PY and YP bleaching of pulps, which were deinked in neutral (cellulase) and alkaline (NaOH, NaOH/${Na_2}{SiO_3}$) ranges, and were treated on kneader, was compared in this study. The brightness of pulps (84.8~88.4% ISO) which were deinked in alkaline or neutral ranges increased up to 88.4%~88.8% ISO after PY or YP bleaching. There was no difference in the brightness between PY and YP bleaching. And the dirt count of bleached pulps was similar each other at the range of 17~38 ppm. The tensile index of bleached pulps was slightly higher in PY bleaching than those in YP bleaching. While with the treatment of kneading, the brightness and dirt count decreased remarkably compared to those of no-kneading. However, the sharp difference in the brightnesses or in dirt count of bleached pulps decreased after bleaching. The brightness of bleached pulps at YP stages was only numberically higher than those at PY stages without regard to the treatment of kneading. Therefore, in the case of the neutral deinkiing process, the conversion of PY bleaching stages to YP bleaching stages was profitable to water loop system, and was harmless in the aspect of the bleach efficiency.

• Korean Journal of Hospice Care
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• v.3 no.2
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• pp.1-11
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• 2003

Purpose: The purpose of this study was to find out the effect of hospice home care on the pain relief and quality of life of terminal cancer patients. Method: Experimental pre and post tests were provided to a single group to see the changes of quality of life of patients who were referred to a hospice home care department after having cancer treatment. They were visited at least 8 times for the duration of 4~6 weeks and were provided a 24 hour phone call service. 41 subjects were transferred to a hospice home care department after being discharged from hospital were selected. Result: 1)The first hypothesis that "the pain score of the subjects after receiving hospice home care would be different from before receiving hospice home care would be different from before receiving hospice home care" which scored 4.06 point at the first test and 3.41 at the second did not statistically show a significant difference(t=1.421 p=1.66), even though the pain score is decreased. 2)The 2nd hypotheses that "the quality of life score of the subjects after receiving hospice home care would be different from before receiving hospice home care" which scored 2.88 point at the first test and 3.39 at the second showed a significant difference(t=-6.759, p=.000) and was supported. Regarding the changes of quality of life score, social aspect(t=-5.745, p=.000), emotional aspect(t=-5.684, p=.000), and spiritual aspect(t=-6.889, p=.000) has significantly been increased, while physical aspect has been more decreased significantly than before the hospice home care is provided(t=4.282, p=.000). Conclusion: It was effective to provide hospice home care in relieving the terminal cancer patients' pain and in improving their quality of life, even though a short term hospice home care for 4-6 weeks was provided.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.88.1-88.1
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• 2012

Silicon nanowires (SiNWs), due to their unusual quantum-confinement effects that lead to superior electrical and optical properties compared to those of the bulk silicon, have been widely researched as a potential building block in a variety of novel electronic devices. The conventional means for the synthesis of SiNWs has been the vapor-liquid-solid method using chemical vapor deposition; however, this method is time consuming, environmentally unfriendly, and do not support vertical growth. As an alternate, the electroless etching method has been proposed, which uses metal catalysts contained in aqueous hydrofluoric acids (HF) for vertically etching the bulk silicon substrate. This new method can support large-area growth in a short time, and vertically aligned SiNWs with high aspect ratio can be readily synthesized with excellent reproducibility. Nonetheless, there still are rooms for improvement such as the poor surface characteristics that lead to degradation in electrical performance, and non-uniformity of the diameter and shapes of the synthesized SiNWs. Here, we report a facile method of SiNWs synthesis having uniform sizes, diameters, and shapes, which may be other than just cylindrical shapes using a modified nanosphere lithography technique. The diameters of the polystyrene nanospheres can be adjustable through varying the time of O2 plasma treatment, which serve as a mask template for metal deposition on a silicon substrate. After the removal of the nanospheres, SiNWs having the exact same shape as the mask are synthesized using wet etching technique in a solution of HF, hydrogen peroxide, and deionized water. Different electrical and optical characteristics were obtained according to the shapes and sizes of the SiNWs, which implies that they can serve specific purposes according to their types.

• Structural Engineering and Mechanics
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• v.88 no.6
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• pp.583-588
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• 2023

Total hip replacement is a crucial intervention for patients with fractured hips who face challenges in natural recovery. The design of durable prostheses requires a comprehensive understanding of the natural processes occurring in bone. This article focuses on static loading analysis, specifically during stumbling activity, aiming to enhance the longevity of prosthetic implants. Three distinct implants, Charnley, Osteal, and Thompson, were selected for a detailed study to determine the most appropriate model. The results revealed critical insights into the distribution of Von Mises stresses on the components of femoral arthroplasty, including the cement, implant, and cortical bone. Furthermore, the examination of shear stress within the cement emerged as a pivotal aspect for all three implants, playing a crucial role in evaluating the performance and durability of hip prostheses. The conclusions drawn from this study strongly suggest that the Thompson model stands out as the most suitable choice for hip joint implants.