• Journal of Engineering Education Research
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• v.13 no.5
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• pp.25-28
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• 2010

The objective of this project is to cultivate interest among junior high school students toward Science & Technology. Six simple experiments will be introduced to the participants (junior high school students) of this project which is focusing on the basic principles of engineering including law of motion, free-fall, force, energy, friction and work. Our student team has been assigned to design six set of experiment according to the principles. The experiments are easy to understand and simple to assemble by the students of age 13 to 15. Experimental manuals were written by the members using simple words complete with figure so that all the participants can understand the procedure of each experiment. In order to make sure the manuals are practically working, the experiment sets were tested and the results were compared with actual theory. As a result, we believe that the experiments can be done by the students within less supervision. The students are able to set up the experiments by using some simple equipment around them. By doing this experiments, we can further our understanding and explain better the principles of energy, force and work.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.1
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• pp.72-82
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• 1999

The objective of this study was to covering of vine the traffic noise barrier and analyse of their growth characteristics. For the purpose of the experiments, chosen were 28 plants. In January 1996 to December 1998, the nursery seedbeds on the Chonju Arboretum in Korea Highway Corporation were seeding and cutting with those species, and a few species were carried out Honam Highway field experiments. The results are summarized as follows ; The germination ratio of seedbed experiments were Wisteria floribunda(88%), Lonicera japonica(86%), Parthenocissus tricuspidata, Paederia scandens(85%), Celastrus orbiculatus(76%), Clematis terniflora var. denticulata(52%), Clematis mandshurica(44%) respectively. The rooting ratio of cutting experiments were Trachelospermum asiaticum var. intermedium(88%), Parthenocissus quinquefolia(87%), Trachelospermum asiaticum var. asiatica(85%), Kadsura japonica(82%), Hedera rhombea(81%), Euonymus fortunei var. radicans(83%), Trachelospermum jasminoides var. pubescens(80%), Lonicera japonica cv. Aureo-reticulata(80%), Trachelospermum asiaticum var. majus(78%), Euonymus radicans cv. Aureo-marginata(66%), in descending order. As a conclusion, this study shows that the traffic noise barrier was effected by Paederia scandens, Lonicera japonica, Parthenocissus quinquefolia, Wisteria floribunda, Parthenocissus tricuspidata in the field experiments and the others were necessary to maintainable management.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.141-146
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• 2002

This paper has studied to obtain the grinding characteristics and optimal grinding conditions of ceramic materials in the grinding with diamond wheel by design of experiments. The load on wheel by varying the feed rate was related with the surface roughness due to the minute destruction phenomenon of grains for the $Si_3\;N_4\;and\;ZrO_2$. The depth of cut is related with the surface roughness because the grinding is carried out by grain shedding process due to the brittle fracture phenomenon for the $A1_2\;O_3$. The major factors affecting the surface roughness and the optimum grinding conditions were obtained with minimum experiments using design of experiments.

• Publications of The Korean Astronomical Society
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• v.25 no.1
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• pp.15-21
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• 2010

We report results of image simulations of the KVN and VLBI experiments of the KVN with several other East Asia VLBI facilities. To investigate their imaging capability a model-generated image of 7 mm SiO maser emission in Mira variables is used. The resulting simulations show that the joint VLBI experiments of the KVN with East Asia VLBI facilities can produce reasonably good images at 7 mm spectral line experiments. However, there are no apparent differences in peak flux densities and images themselves in the simulations among different combinations of these facilities. In addition, the simulated images of observations which include bigger antennas do not show any expected improvement to the image sensitivity. The small variations in the peak flux density and similar image sensitivity, irrespective of different antenna sizes or numbers of baselines used in the simulations, turn out due to a specific characteristic of the adopted model image. Test simulations using another SiO maser image from R Cas observations prove that the participation of bigger antennas in the VLBI experiments does improve image sensitivity. We confirm the need of additional longer baselines in the experiments of the East Asia VLBI facilities to study very compact maser clumps on sub-milliarcsecond scales.

• Korean journal of applied entomology
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• v.39 no.2
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• pp.111-115
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• 2000

Fifty-two nematode predatory fungi were isolated from 37 soil samples collected from eight provinces in Korea. Isolated fungi were tested their predacity against Rhabditis sp. and Meloidogyne incognita in petri dish, and against M. incognita in greenhouse pot experiments. Fifty isolates had trapping organ of adhesive networks and two isolates had adhesive column or adhesive knob. In petri dish experiments, 5 1 isolates against Rhubditis sp. and 26 isolates against M. incognita showed over 91 % of predacity; in greenhouse experiments, however, only three isolates showed over 81% of predacity. These results imply that the results from the laboratory experiments are not consistent with those from the greenhouse experiments. Therefore, to select a promising biocontrol predatory fungi for plant-parasitic nematodes, the screening experiment should be conducted in conditions close to nature.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.3
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• pp.18-26
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• 2001

Environmental chamber (EC) is an experimental facility used to analyze the characteristics of thermal response of testing objects by the artificial control of weather conditions. The EC in KIFR can simulate the weather conditions by the control of temperature, humidity, and solar radiation. A two-storied testing building is located inside EC. For the exact thermal response analysis of testing building, monthly or yearly scheduled operations are necessary. Although this long term operation gives the exact experimental data, it requires a high operational cost, long duration, and lots of manpower. Therefore it is necessary to perform the shortened experiments without sacrificing the validity of the obtained results. Since the characteristics of thermal response from the shortened experiments are different from the full time results, the analytical method to analyze the thermal response from the shortened experiments to estimate a full times results is developed in this study The thermal response of testing building is performed using commercial software TRNSYS.

• Journal of Ocean Engineering and Technology
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• v.34 no.4
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• pp.253-262
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• 2020

This study provides a comparative analysis of experiments-based enhancements and sensitivity evaluations for the structural design of an automatic ocean salt collector under various load conditions. The sizing variables of the structural members were considered as design factors. The strength and weight performances were selected as output responses. The design of experiments used in the comparative study consisted of the orthogonal array design, Box-Behnken design, and central composite design. The response surface model, one of the metamodels, was applied to the approximate model generation. The design enhancement performance metrics, including numerical costs and weight minimization, according to the design of experiments, were compared from the best design case results. The central composite design method showed the most enhanced design results for the structural design of the automatic ocean salt collector.

• Journal of the Korean Society of Safety
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• v.31 no.1
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• pp.41-47
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• 2016

The rolling stock is composed of several cars. In order to operate in combination, it is necessary to connect the device, called coupler, between the rolling stocks. When the collision occurs between cars, couplers should be able to absorb the shock. Urban railway has used only rubber absorbers. But recently, the hydraulic buffer has been considered in general railway. In order to know the performance of the buffer it should be conducted to experiments. But whenever this combination change, we should experiments to know a lot of the dynamic behavior of each coupler. These experiments are generally replaced by the simulation, since a lot of time and cost consuming. The quasi-static map of hydraulic buffer obtained by the experiments is required for the simulation. However, the experiments for obtaining such a quasi-static map is costly and time consuming. In this paper, it proposes a method for deriving the quasi-static map of hydraulic buffer from the theoretical model.

• Journal of The Korean Association For Science Education
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• v.9 no.2
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• pp.29-45
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• 1989

The purpose of this paper is to study the operational skills of apparatuses in observation and experiments a point of view of the teaching-learning guidance of the middle school science. In order to understand the actual condition of the field learner, the achivment levels of learner have been investigated on the operational skills of apparatuses, observation and experiments through 1120 students of 16 middle schools. The results showed that there were large differences at each item and especially, in animate natural part(physics and chemistry), the handling ability was very low to average 33 percentage. By the result of analyzing the actual condition of the experiment and field science from the question of 114 science teachers who work in 40 middle schools in P distriet. it has been recognized that though the lessons through the experiments stimulate the motivation of learning, it couldn't be mamaged efficently because of all the educational conditions. And it was revealed that the major part of Experiment was performed not by student who is subjective in the course of learning but by teacher through experiments.

• Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.30-37
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• 2006

We performed experiments on the uptake and excretion of dissolved organic phosphorus (DOP) using two toxic dinoflagellates, Alexandrium tamarense Lebour (Balech) and Gymnodinium catenatum Graham, isolated from Hiroshima Bay, Japan. ATP (adenosine triphosphate), UMP (uridine-5-monophosphate), G-6-P (glucose-6-phosphate) and Glycero-P (glycerophosphate) were used as DOP sources in preliminary uptake experiments. ATP was selected as the DOP species for the short-tenn uptake experiment because preliminary experiments showed it to be the DOP source used by both species. Although the $K_s$ values of A. tamarense and G. catenatum (5.63 and $7.61{\mu}M$, respectively) obtained from the short-term experiments for ATP were only slightly higher than those reported for dissolved inorganic phosphorus (DIP), the ${\rho}_{max}$ values (5.04 pmol/cell/h and 13.4 pmol/cell/h, respectively) were much higher. The DOP excretion rate in batch-culture experiments was estimated at 0.084 pmol/cell/h for A. tamarense and 0.012 pmol/cell/h for G. catenatum, accounting for about 30% and 25%, respectively, of the assimilated phosphorus. Our results suggest that the DIP-depleted conditions of Hiroshima Bay favor these two species by supporting their ability to use DOP.