• 한국초등과학교육학회지:초등과학교육
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• 제33권2호
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• pp.306-321
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• 2014

This study aims to analyze difficulties that pre-service elementary teachers experience in investigating the life cycle of a common cabbage butterfly in person. As difficulties they face during the process of this research, they pointed out collecting eggs, observing molting, creating environments for a breeding cage, feeding, building a breeding cage, and making butterfly specimens. Out of all the environmental difficulties related to their school fields, they pointed out a difficulty of time management most of all, followed by placing a breeding cage in the classroom and the lack of microscopes for observation. In regard to difficulties related to their evaluations on students' activities, they found it difficult to evaluate students' activity with the life cycle of an insect in the aspect of knowledge and even to set evaluation criteria. Besides, many of them responded that it would be appropriate to evaluate a research on the life cycle of an insect through a portfolio or an observation journal. In regard to difficulties in terms of teachers' knowledge, they found it difficult to understand insect molting, metamorphoses, complete metamorphoses, incomplete metamorphoses, the structure of an insect body, and how to distinguish a female insect from a male one. In regard to the application of class models, they knew it is important for students to have various experiences through direct observation, so the experience-based learning model was proper for the process of observing the life cycle of a common cabbage butterfly. However, they found it difficult for students to observe each stage of the life cycle in person.

• 한국정밀공학회지
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• 제24권7호
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• pp.90-97
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• 2007

This paper describes the development of 6-axis force/moment sensor considered adult weight far an intelligent foot of humanoid robot. In order to walk on uneven terrain safely, the foot should perceive the applied forces Fx, Fy, Fz and moments Mx, My, Mz to itself and control the foot using the forces and moments. The applied forces and moments should be measured from a 6-axis force/moment sensor attached to the foot, which is composed of Fx sensor, Fy sensor, Fz sensor, Mx sensor, My sensor and Mz sensor in a body. Each sensor should get the deferent rated load, because the applied forces and moments to foot in walking are deferent. Therefore, one of the important things in the sensor is to design each sensor with the deferent rated load and the same rated output. In this paper, a 6-axis force/moment sensor (rated load of Fx and Fy are 500Nm and Fz sensor is 1000N, and those of Mx and My are 18Nm, Mz sensor is 8Nm) for perceiving forces and moments in a humanoid robot's foot was developed using many PPBs (parallel plate-beams). The structure of the sensor was newly modeled, and the sensing elements (plate-beams) of the sensor were designed using by ANSYS software (FEM (Finite Element Method) program). Then, a 6-axis force/moment sensor was fabricated by attaching strain-gages on the sensing elements, and the characteristic test of the developed sensor was carried out. The rated outputs from FEM analysis agree well with that from the characteristic test.

• Structural Engineering and Mechanics
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• 제61권3호
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• pp.419-426
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• 2017

Recently, the transportation of dangerous explosive goods is increasing, which makes vehicle blasting accidents a potential threat for the safety of bridge structures. In addition, blasting accidents happen more easily when earthquake occurs. Excessive dynamic response of bridges under extreme loads may cause local member damage, serviceability issues, or even failure of the whole structure. In this paper, a new explosion-proof and aseismic system is proposed including cable support damping bearing and steel-fiber reinforced concrete based on the existing researches. Then, considering one 40m-span simply supported concrete T-bridge as the prototype, through scale model test and numerical simulation, the dynamic response of the bridge under three conditions including only earthquake, only blast load and the combination of the two extreme loads is obtained and the applicability of this explosion-proof and aseismic system is explored. Results of the study show that this explosion-proof and aseismic system has good adaptability to seism and blast load at different level. The reducing vibration isolation efficiency of cable support damping bearing is pretty high. Increasing cables does not affect the good shock-absorption performance of the original bearing. The new system is good at shock absorption and displacement limitation. It works well in reducing the vertical dynamic response of beam body, and could limit the relative displacement between main girder and capping beam in different orientation so as to solve the problem of beam falling. The study also shows that the enhancement of steel fibers in concrete could significantly improve the blast resistance of main beam. Results of this paper can be used in the process of antiknock design, and provide strong theoretical basis for comprehensive protection and support of girder bridges.

• 한국응용곤충학회지
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• 제35권3호
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• pp.238-242
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• 1996

몇가지 협력제의 7-ethoxy precocene II와 협력작용을 통한 활성증가와 작용기작을 구명하기 위하여 mikweed bug, Oncopeltus fasciatus 2령충에 항유약호르몬유사물과 협력제가 처리된 petri dish에 접종하여 생리활성 정도를 측정하였다. 얻어진 결과는 다음과 같다. 7-Ehtoxy precocene II의 반수활성농도는 $1.18\mu$g/$\textrm{cm}^2$이었다. 7-Ethoxy precocene II와 다른 산화저해제인 RO20-9747의 협력비가 14.05로 가장 높았고 그들의 반수활성농도는 $0.084\mu$$g/\textrm{cm}^2$이었다. 7-Ethoxy precocene II와 다른 협력제 1종, 2종, 4종을 조합을 달리하여 처리하였을 때 뚜렷한 협력작용 증가효과를 가져오지 못했다. 이상의 결과에서 다른 협력제들은 곤충의 방어기작을 알라타체를 포함하여 비선택적으로 저해하는 것으로 생각되었으나 RO20-9747은 7-ethoxy precocene II가 알라타체로 이행하는데 까지 곤충의 방어적 산화기작인 monooxygenase 활성을 선택적으로 저해함으로써 7-ethoxy precocene II가 알라타체로 이행량이 증가하여 활성증가를 가져온 것으로 생각되었다.

• 한국실내디자인학회논문집
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• 제24권2호
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• pp.88-99
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• 2015

As architecture is designed for humans to live in based on practicality, what one experiences within such spaces is important. Such experiences are not felt only by appreciating the structure's appearance, but involve physical presence inside the space and the deepening of the individuals relationship with the space through the body's sensory perception. However, in modern times there is a much greater tendency to rely on superficial experiences by way of images or tastes rather than more meaningful human participation, while the standardization of the object universe is gradually erasing the uniqueness of experience. In light of this, the restoration of emotional and sensory spatial experiences through the design of sensory spaces can be regarded as an important task in modern spatial design. This study contemplated the meaning of emotional spatial experiences through a phenomenological understanding of such experiences, and analyzed the meaning and main factors in the creation of spatial atmosphere as a phenomenon of spatial experience. In addition, we highlighted the fact that spatial atmosphere can be applied as space design methodology by devising methods of expression through an analysis of actual examples. O.F. Bollnow's space theory and the spatial design of Peter Zumthor were the subjects of this analysis. The spatial atmosphere analyzed using Bullnow's theory is a phenomenon in which both the human and space are connected and the ensuing spatial experience embodies the emotions of both. This spatial atmosphere can be understood as a condition in which the human and space are fused together. Furthermore, coincidental/accidental meeting, mediums using potential objects, reorganization of the center due to autonomous boundaries, as well as the three temporalities were identified as the main factors in the creation of spatial atmosphere. Based on this analysis, through the identification of methods of expression for spatial atmosphere in Zumthor's spaces.

• 대한기계학회논문집B
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• 제26권1호
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• pp.159-169
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• 2002

The present study investigates in detail the combined effects of the Coriolis and centrifugal farce on the development of laminar flows in a square-sectioned U-bend rotating about an axis parallel to the center of bend curvature. When a viscous fluid flows through a rotating curved region, two types of secondary flow occur. One is caused by the Coriolis force due to the rotation of U-bend and the other by the centrifugal farce due to the curvature of U-bend. When the values of Rossby number and curvature ratio are large, the flow field in a rotating U-bend can be represented by two dimensionless parameters ; the Dean number K$\_$LC/=Re/√λ and a body ratio F=λ/Po. For positive rotation, where the rotation is in the same direction as that of the main flow, both the Coriolis force and the centrifugal force act radially outwards, the directions of the two secondary flows are the same. Therefore, the flow structure is qualitatively similar to that observed in a stationary curved duct with a larger f7c. On the other hand, in case of negative rotation, where two farces act in opposite direction, more complex flow fields can be observed depending on the relative magnitudes of the forces.

• 한국실내디자인학회논문집
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• 제22권5호
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• pp.320-327
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• 2013

In order to maintain and protect professionalism in color planning, the present study examined the process at the time of realization of color through color inspection and supervision in the actual construction site and suggested plans for improvement. Reflecting the characteristics that the governing body of the construction site is not a private person but an organization, the present study aims to provide institutional measures so that the supervisor of color construction at the actual site of construction can propose concerns related to proper construction at the right time, and the matters cannot be decided from the perspective of a layman. The institutional measures are proposed through the case of application of a process at the construction stage of the color planning at the construction site of Muju Taekwondo Park. First, the process clarified where the responsibility lies by specifying special conditions concerning color inspection on the field guide and color contract. Second, the sample for building materials was selected after obtaining it from a company capable of supply and is appropriate for the planned unit cost so that it could play an important role in realizing colors at the stage of basic design. Third, the process of construction was ensured not by temporary selection of colors but by continuous approval of colors in consideration of the conditions of construction site through letter of approval of color at each stage and point of time. Fourth, coordination of various color elements of other fields including landscape, interior, and electricity ensured construction of the whole structure in one color concept. Fifth, color inspection through the mock up of the site will minimize erroneous construction and reconstruction and prevent decrease in productivity. Sixth, this study also suggested more comfortable and positive color environment through evaluation by experts and users. The researcher of this study expects that color experts actively participate in the stage of construction to contribute to improvement of the color environment.

• 한국농공학회지
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• 제11권1호
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• pp.1580-1597
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• 1969

1. The field test of our experiment comparing the traditional syckle and the new manually pulled cutter showed that the working efficiency of the manually pulled cutter is about two times higher than that of the syckle. The operator can standerect while using the manually pulled cutter, thus reducing fatigue. Because of the reduction in body fatigue, the operator is able to work more total hours, making the manually pulled harvester three times more efficient than the syckle. 2. The optimum angle for the V-shaped cutter blade varies according to the number of the hiller, but in manufacturing the cutter, the range must be controlled between $35^{\circ}{\sim}45^{\circ}$. 3. The radius of curvature of the V-shaped blade is closely related to the blade angle. The best results were obtained when the radii of curvature were r=32cm with $35^{\circ}$ angle, r=153mm with $45^{\circ}$ angle, and r=220mm with $40^{\circ}$ angle. 4. The hardness distribution test of the blade showed great differences between foreign made and domestic made blades. The heat treatment method must be greatly improved for superior hardness distribution. 5. Although the efficiency of the manually pushed cutter is equal to that of the manually pulled cutter, the manually pushed cutter is not only more expensive to produce but also has a much more complicated structure than the manually pulled cutter. Because of our rural economic conditions, the power harvester which is utilized in foreign countries can not yet be introduced here. Thus, the manually pulled cutter should be popularized in our rural areas until economic conditions will allow us to introduce power harvesters. 6. The use of the manually pulled cutter will make it possible for an operator to harvest an area in only one-third of the time that it would take to harvest the same area with a traditional syckle, and it will make it possible for an operator to earn about 8,000 won for harvesting 10 Jung-bo: such benefits will help in increasing farm income and will contribute to farm modernization.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.904-907
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• 2002

Optical disk drive device is improved in rotating speed for faster data reading. In the case of CD-ROM, rotating speed is over 10000 rpm in the practical use. As a result of high rotating speed, unexpected effects as like increasing disk fluctuation and acoustic noise are raised by the air friction on the rotating disk and the eccentricity of rotating parts. The overall acoustic noise of running CD-ROM could be classified into two different characterized noise. The first is the structural-borne noise which is generated from vibrating solid body. By the reason, the signal of structural borne noise has very similar to the signal of surface vibrating one. It has dense noise energy at specific frequency region. The other is the air-borne noise which is generated from turbulence or vortex caused by friction between disk and air. The signal of air-borne noise has no dominant peak point at acoustic pressure-frequency domain. The noise energy is widely distributed while comparatively high and large frequency region. The structural-borne noise could be reduced by reducing vibration of structure and in addition it's target reducing frequency is narrow. However the air-borne noise reduction is effectively needed of enclosing method for the noise source located near the disk surface because it is difficult to define target frequency point. In this study, the acoustic noise at driving CD-ROM is classified by the sides of it's character and tried to reduce the overall acoustic noise.

• 약학회지
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• 제56권1호
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• pp.20-25
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• 2012

In Northeast Asia, Paeoniae Radix has been used in treatments of inflammation-causing diseases such as arthritis for many centuries. Paeoniflorin, one of the principle bioactive monoterpene glucosides from the paeony root, is reported to be mostly responsible for the effectiveness of the treatments. However, the anti-inflammatory effect of a monoterpene, paeoniflorigenone (PFG) which partially has the moiety of paeoniflorin minus a glucose structure is unknown. Thus, the aim of this work was to investigate anti-inflammatory activity of PFG. For the investigation, PFG activity on the NO (nitric oxide) production from LPS-stimulated macrophages, and the anti-inflammatory effect was tested in the animal model of septic arthritis caused by Candida albicans, a major etiological agent for septic arthritis. For induction of the arthritis, mice were administered with an emulsion of C. albicans cell wall (CACW) mixed with Complete Freund's Adjuvant (CFA) via footpad-injection (Day 0); PFG at a dose of 0.5 or 1 mg/mouse (25 or 50 mg/kg of body-weight) was given to the animals on Day 3, 6, and 9; footpads were scored for arthritis. Moreover, the PFG effect on proliferation of T-lymphocyte that causes aggravation of arthritis was additionally tested. Data resulting from those tests showed that PFG inhibited the NO production from the stimulated macrophage in a dose dependent manner (P<0.05), indicating that PFG is an anti-inflammatory. To confirm the in-vitro results, anti-inflammatory activity of PFG was determined against C. albicans-caused septic arthritis. Data showed that PFG-treatment reduced footpad-swelling which indicates that PFG has anti-arthritic effect (P<0.05), which is therapeutic. The anti-arthritic effect appeared to be mediated by PFG suppression of T-cell proliferation. Ultimately, PFG, a monoterpene component, has anti-inflammatory activity analogous to paeoniflorin. The anti-inflammatory activity treats the septic arthritis due to a pathogenic fungus C. albicans.