• Resources Recycling
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• v.21 no.3
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• pp.28-38
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• 2012

The purpose of this paper is to develop the alkali-activated concrete which uses 100% fly ash as a binder without any cement. The compressive strength of the mortar was examined depending on the chemical change in alkali-activator through SEM and SEM/EDS observations and the XRD analysis. It was found from the test that the higher molar concentration induced the greater effect on the initial strength, and that $Si^{4+}$ and $Al^{3+}$ were eluted relative to the compressive strength of mortar. In addition, it was confirmed that Al and Si were determined to be most influential ingredients on the microstructural development of the mortar, and that the different ingredient of the activator was almost no change in solidity from the XRD analysis.

• Journal of the Korean Applied Science and Technology
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• v.29 no.4
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• pp.599-609
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• 2012

The objective of this research is to reuse and recycle the oyster shell wastes as a useful of antioxidant beads for foodstuff preservation through the treatment of oyster shell and seaweed pulp. This research is divided into two parts. In the first, designing and preparation of pilot scale condition was accomplished. The second part dealt with establishing the optimized manufacturing condition for [A],[B],[C-a],[C-b] compounds, and analyzing these products. The pilot scale preparation was composed of modify synthesized seaweed pulp / Cl-starch and it's various bead form were prepared with various weight ratios using polar protic solvents. In addition, with increased seaweed pulp content in the blends, antibacterial property values of seaweed pulp/Ag-oyster shell blend was decreased, however, the antioxidant and bead's solidity properties increased.

• Journal of Fashion Business
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• v.5 no.3
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• pp.9-18
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• 2001

This study is to provide basic data for the development of domestic ready-made shoes industry by illustrating any problem in regards to the ready-made shoes for ordinary salary men through looking into its uses and gratifications. Subjects for this study were in between twenties and sixties by applying convenient random sampling method, which was done in January to February, 2001. The results were as follows: 1. General foot shape of subjects was that foot breadth was wide whereas instep height was average. In regards to the metamorphic parts of foot, the most metamorphic part was the fifth toe which could be occurred by disagreeable shoes to foot. 2. General salary men (69.5%) wear the formal shoes and their wearing time per day is over 10 hours (49%), which illustrates that more suitable and convenient functional shoes needs to be developed. 3. Almost of subjects tended to purchase ready-made shoes, and their concerns to be considered when to purchase ready-made shoes were its size and solidity. This finding suggests that the size specification of the ready-made shoes needs to be more specific in terms of its length as well as foot breadth. 4. The most unsatisfied point on the ready-made shoes was the foot breadth. According to the Crosstabulation analysis on the discomfort part and the foot breadth, there existed a significant correlation between the discomfort part and the foot breadth (p$\leq$0.05). The above results make clear that overall salary men have complaints on the ready-made formal shoes in terms of its size and wearing comfort level. This suggests that the subdivision of the shoes size specification needs to be developed to improve the wearing comfort level.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.8
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• pp.735-743
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• 2011

In this study, the distribution of surface pressure was measured in a steady state on a turbine blade which was moved the injected region and receded the stagnation region using a linear cascade apparatus. Axial-type blades were used and the blade chord was 200mm. The rectangular nozzle was applied and its size was $200mm{\times}200mm$. The experiment was done at $3{\times}10^5$ of Reynolds number based on the chord. The surface pressures on the blade were measured at three different nozzle angles of $58^{\circ}$, $65^{\circ}$ and $72^{\circ}$ for off-design performance test. In addition, three different solidities of 1.25, 1.38 and 1.67 were applied. From the results, the low solidity caused the low pressure on the blade suction surface at entering region and the reverse rotating force was generated at the low nozzle angle. The positive incidence also made the pressure lower on the suction surface at entering region.

• Fire Science and Engineering
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• v.14 no.4
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• pp.7-16
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• 2000

In the study, three criteria(toxicity, fire & explosion, environment) and damage prediction method for each case was set up, and all these criteria were applied to the subject substance that was selected as hazardous level by integrating all criteria through Algorithm. Particularly, the environment criterion is a comprehensive concept, environment index modeling by combining USCG(United State Coast Guard) & MSDS(Material Safety Data Sheet) environment criteria classifications and the environment part of MFPA's health hazardousnes(Nh). And for damage prediction method of each criterion were adopted and they were applied to hazardous chemical substances in use or stored by chemical substance related enterprises located in each region that made possible to set up total hazard level of used substances(inflammability, poisonousness and counteraction on a unit substance, and hazard level & display modeling on environment) & damage prediction in case of accident & solidity setup(CPQRA: Chemical Process Quantitative Risk Assessment, IAEA: International Atomic Energy Agency, VZ eq: Vulnerable Zone) risk counter. Thus it is deemed that it can be applied to toxic substance leakage that can happen during any chemical processing & storage, application as a tool for prior safety evaluation through potential dangerousness computation of fire & explosion.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.9
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• pp.16-26
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• 2005

The aerodynamic design of a proprotor for the Smart UAV adopting tiltrotor aircraft concept is conducted in this study. Since proprotor of tiltrotor aircraft is operated at both rotary and fixed wing mode with single configuration rotor, the proprotor has to be designed to meet performance requirements for both flight modes. The aerodynamic design of proprotor is accomplished by combining three sources of data - the proprotor performance data, the aerodynamic data of vehicle, and the performance data of engine. The performance analysis code for proprotor is based on the combined momentum and blade element theory and validated by comparison with the TRAM data. In order to design configuration for a proprotor satisfying requirements for both rotary and fixed wing mode, various kind of performance maps are constructed for many performance and configuration parameters. From the analysis the twist angle of 38 degrees and the solidity of 0.118 are decided to be the optimal geometric parameters for both operating conditions.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.208-213
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• 2011

This study was carried out to determine the effect of medium solidity, salt strength, sugar and nitrogen sources, and pH levels on in vitro multiplication of pathogen-free yam (Dioscorea opposita Thunb.). Liquid medium was more effective in the growth of plant height, fresh weight, and formation of microbulb than the solid medium. Optimal condition for plant fresh weight, growth, and multiplication axillary bud was in 1MS salt strength with 60 $g{\cdot}L^{-1}$ sucrose and half strength of $KNO_3$. Optimal condition for microbulb formation was $\frac{1}{2}$ MS salt strength supplemented with glucose 60 $g{\cdot}L^{-1}$ and half strength of $KNO_3$. The number of leaves and nodes were sharply increased from 2 to 5 weeks, whereas plant fresh weight was steadily increased from 3 to 11 weeks after inoculation. Microbulbs were formed at 2 weeks after inoculation and continuously increased until 12 weeks.

• Conservation Science in Museum
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• v.6
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• pp.3-10
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• 2005

In the course of preparing for the transfer of the Boshin-gak Bell, which was designated as Treasure No. 2, due to the transfer of the National Museum of Korea, the current internal cracks and defects in the founding of the bell were examined in order to verify its solidity through γ-ray penetration via ⁶⁰Co. The bell's compositions were also examined with x-ray fluorescence spectroscopy. The result showed that the bell had 65.2% cracks when viewed from the horizontal direction and 62.5% cracks when viewed from the vertical direction. The cracks had approximately 5cm depth. In addition, the result of examining the composition of the bell revealed that it was made of 89~92% copper and 7.5~10.5% tin as well as traces of impurities including 0.1~0.3% lead and not more than 0.1% iron, manganese, etc.

• Journal of Digital Contents Society
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• v.14 no.1
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• pp.65-72
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• 2013

Current and future parallel computing model has been suggested for running and solving large-scale application problems such as climate, bio, cryptology, and astronomy, etc. Parallel computing is a form of computation in which many calculations are carried out simultaneously. And we are able to shorten the execution time of the program, as well as can extend the scale of the problem that can be solved. In this paper, we perform the actual cryptographic algorithms through parallel processing and evaluate its efficiency. Length of the key, which is stable criterion of cryptographic algorithm, judged according to the amount of complete enumeration computation. So we present a detailed procedure of DES key search cryptographic algorithms for executing of enumeration computation in parallel processing environment. And then, we did the simulation through applying to clustering system. As a result, we can measure the safety and solidity of cryptographic algorithm.

• Wind and Structures
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• v.13 no.5
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• pp.413-431
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• 2010

The focus of this article is on the assessment of vertical wind vector components and their aerodynamic impact on lattice framework, specifically two distinct sections of a guyed transmission tower. Thunderstorm winds, notably very localized events such as convective downdrafts (including downbursts) and tornadoes, result in a different load on a tower's structural system in terms of magnitude and spatial distribution when compared to horizontal synoptic winds. Findings of previous model-scale experiments are outlined and their results considered for the development of a testing rig that allows for rotation about multiple body axes through a series of wind tunnel tests. Experimental results for the wind loads on two unique experimental models are presented and the difference in behaviour discussed. For a model cross arm with a solidity ratio of approximately 30%, the drag load was increased by 14% when at a pitch angle of $20^{\circ}$. Although the effects of rotation about the vertical body axis, or the traditional 'angle of attack', are recognized by design codes as being significant, provisions for vertical winds are absent from each set of wind loading specifications examined. The inclusion of a factor to relate winds with a vertical component to the horizontal speed is evaluated as a vertical wind factor applicable to load calculations. Member complexity and asymmetric geometry often complicate the use of lattice wind loading provisions, which is a challenge that extends to future studies and codification. Nevertheless, the present work is intended to establish a basis for such studies.