• 한국소음진동공학회논문집
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• 제22권12호
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• pp.1220-1226
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• 2012

This paper proposes a novel type of tactile device utilizing magnetorheological(MR) fluid which can be applicable for haptic master of minimally invasive surgery(MIS) robotic system. The salient feature of the controllability of rheological properties by the intensity of the magnetic field(or current) makes this potential candidate of the tactile device. As a first step, an appropriate size of the tactile device is designed and manufactured via magnetic analysis. Secondly, in order to determine proper input magnetic field the repulsive forces of the real body parts such as hand and neck are measured. Subsequently, the repulsive forces of the tactile device are measured by dividing 5 areas. The final step of this work is to obtain desired force in real implementation. Thus, in order to demonstrate this goal a neuro-fuzzy logic is applied to get the desired repulsive force and the error between the desired and actual force is evaluated.

• 교육시설
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• 제11권1호
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• pp.39-46
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• 2004

The objective of this study is to propose the architectural basic data for the planning of kindergarten attached to the elementary school. For this study, we selected and investigated 23kindergartens in Gwangju city. The results of this study are as follows. 1) The elementary school in separated style had the advantage of securing educational space and reducing interference with students of elementary school. But it had the problem in using the facilities of elementary school. So we have to consider the kindergarten to be located near by dinning room, multi-purpose hall. 2) Concentrating the entrance, it makes the inside and outside space use easily. For the actual use, we have to establish facilities for convenience in outer-space. 3) For each room, we suggest guides as follow. The classroom and the playroom have to be combined for flexibility and supervision. In the planning of toilet, it must have sliding door for confirm the inside situation and reasonable height partition to consider the student's body-size. The shape of teacher's room must be open-type for supervising children but protect the entry of children. There is consideration for the material room and the sleeping room for all-day-long class.

• 한국태양에너지학회 논문집
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• 제21권2호
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• pp.69-78
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• 2001

This paper introduces the physical phenomena involved in Direct Contact Heat Exchangers (DCHXs) and also investigates the possibility of applying of EIT(Electrical Impedance Tomography) technique for capturing the images of dispersed phases as they stream through a stagnant body of water. A number of cases are studied where two dimensional cross-sectional static images are given for fictitious and actual masses present in a column of water(saline solution). In most direct contact liquid-liquid heat exchangers, oil or hydrocarbon with a density different(lighter or heavier) from water is normally used as dispersed working fluid. The main difficulty that arises with this arrangement lies in the elucidation of complicated flow field where the dispersed phase fluid tends to change its shape and size constantly during its journey through the other phase(water). This paper presents a number of results with different types of dispersed phases that are immiscible with water. The EIT technique has been employed in this context to test its applicability in capturing the dynamic images of dispersed phases. It shows static images of dispersed phases where dynamic images could be obtained by simply extending the algorithms and strategies employed in the present analysis.

• 복식
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• 제60권5호
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• pp.88-105
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• 2010

The purpose of this study is to grasp the actual wearing conditions, inconvenience and problems with cycle wear. To attain this purpose, a questionnaire was completed by direct observation and by interviewing bicyclists. The questionnaire was given to 273 bicyclists. The questionnaire consisted of items that are related to concerns with dressing appropriately and enhancement of physical performance through dress. Following are the results of this study. According to the survey, many of them purchased imported cycle wear rather than national cycle wear, and the satisfaction according with purchase rate was low. Bicyclists were uneasy with finding right size cycle wear especially for women. It turned out that the area of the knee and elbow are mostly the areas that they get hurt while riding. Even though the knee and elbow are the mostly hurt area, bicyclists do not prefer to wear appropriate protector for the knee and elbow to excel in their performance in cycling. In material related questions, lower dissatisfaction was indicated for the lints caused by fraction. Average satisfaction was indicated for the distortion after washing, changes in color, touch of the fabric, matters with static and sweat. With regard to the areas where the bicyclists felt discomfort was highly indicated with lower-body clothing. Discomfort was highly indicated with crotch area when riding long period of time. Also when riding a cycle, discomfort was indicated with the leggings cuffs when it comes upward with riding motion. Most of the bicyclists felt the tight fitting leggings were embarrassing.

• 소음진동
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• 제10권5호
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• pp.775-782
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• 2000

Being carried out a number of studies for the resilient mounting system of automobile engine than that of the studies for marine engines, many research results for the case of the resilient mounting system of the automobile engine have applied in the analysis for the case of marine engine. However, the size and the power of automobile engines are not only relatively small but also their operating conditions are quite different form those of marine engines. For the analysis of the automobile engine Wavelet shrinkage, misfire condition and unload condition have not been considered. Accordingly , it is not desirable to apply the results obtained form the case of automobile engines to the case of marine engines. In this study , exciting and damping forces working on the marine engine are formulated mathematically in order to apply to the design of a resilient mounting system of engine effectively. futhermore, some mathematical formulation for the analysis of the transmissibility of multi-body system are proposed. A new computer program which is able to calculate the free vibration, the transmissibility and the forced vibration of a resilient mounting system has been developed, As an application of this developed computer program, the dynamic behavior of resilient system with an actual rubber spring for the case of 6-degree-of-freedom system and 36-degree-of-freedom system are evaluated quantitatively.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.415-420
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• 2012

This paper proposes a novel type of tactile device utilizing magnetorheological (MR) fluid which can be applicable for haptic master of minimally invasive surgery (MIS) robotic system. The salient feature of the controllability of rheological properties by the intensity of the magnetic field (or current) makes this potential candidate of the tactile device. As a first step, an appropriate size of the tactile device is designed and manufactured via magnetic analysis. Secondly, in order to determine proper input magnetic field the repulsive forces of the real body parts such as hand and neck are measured. Subsequently, the repulsive forces of the tactile device are measured by dividing 5 areas. The final step of this work is to obtain desired force in real implementation. Thus, in order to demonstrate this goal a neuro-fuzzy logic is applied to get the desired repulsive force and the error between the desired and actual force is evaluated.

• ALGAE
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• 제36권1호
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• pp.51-60
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• 2021

The sea urchin, Mesocentrotus nudus, is widely distributed in North West Pacific regions. It has a substantial impact on macroalgal communities as a generalist herbivore. This study examined various aspects of its feeding ecology, including algal preference, foraging behaviors, and possible effects of past feeding history on its algal preference. We used six common algal species (Ulva australis, Undaria pinnatifida, Sargassum confusum, Dictyopteris divaricata, Grateloupia elliptica, and Grateloupia angusta) from the east coast of Korea as food choice in a series of indoor aquarium experiments. The first choice of starved M. nudus was exclusively U. pinnatifida, followed by G. elliptica and S. confusum. Unlike large urchins, small urchins equally preferred U. pinnatifida and G. elliptica. On the other hand, Undaria-fed urchins preferred to feed only G. elliptica, although its preference slightly differed over time. We then grouped sea urchins into three categories (starved, Undaria-fed, mixed species-fed) to observe 12-days feeding preference as well as early foraging movements. Foraging behaviors of the three groups were distinctively different, although they could not completely reflect the actual consumption. For example, U. australis was highly attractive, but rarely eaten. Undaria-fed urchins seemed to stay with only S. confusum and U. australis. This study demonstrates that M. nudus shows high flexibility in food preference depending on past feeding history and body size. Its foraging behaviors are also affected by past feeding conditions, exhibiting active chemoreceptive movements.

• 패션비즈니스
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• 제26권6호
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• pp.32-46
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• 2022

The purpose of this study is to explore a three-dimensional (3D) simulation of skirt shape concepts by manipulating circumferences and lengths via parametric design in the fashion design concept stage. This study also intends to propose a modeling method that can judge and transform the shape through immediate parameter adjustment. We looked at cases that utilized parametric design in other fields of fashion design, reviewed and analyzed the variables used in each study, and constructed parameters suitable to implement skirt fashion design. The traditional design elements required for skirt design, namely waist and hip circumferences, were set as variables in this study. The parametric design was developed to generate ideas of two skirt silhouettes (tight and flared) and three lengths (mini, knee-length, and maxi). To apply the skirt design implemented through variables to the actual 3D human shape, the shape data of women in their 20s and 30s were randomly selected from the 5th human data of Size Korea. Skirt design silhouette modeling was performed by adjusting the variable values according to body type. Parametric design has the potential to help develop design ideas in the field of fashion design, considering the method and characteristics of parameters of the variety of variables and rapid modification. Furthermore, if systematic research on variables and options among fashion design elements is conducted, the possibility of converging them into customization or co-design fashion design processes could be confirmed.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.471-473
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• 2002

Public concerns associated with the electromagnetic field (EMF) exposures from mobile phones on human body are increased. Although studies on the effects of the EMF exposures on human have been carried out for a long time, it is not proved yet whether the EMF effect is harmful or not. Based on the scientific results by experts, EMF exposure limits have been regulated as a precautionary approach on the assumption that the EMF effect may be harmful. It is well known that absorbed EMF can be transformed into heat within biological tissues and that thermal effects are related with the specific absorption rate (SAR) distribution. However, the relative magnitude and distribution of the energies are not well defined. Although there is comprehensive information of the thermal effects, most of them come from animal and in vitro studies. Considerable efforts have been made to analyze the EMF absorption model while the actual temperature in the human body has been rarely measured. Temperature changes on the face of a healthy male volunteer were studied. A digital mobile phone of 1.8GHz was used. A digital infrared imaging system (IRIS-5000, Medicore, Seoul, Korea) was applied to take infrared pictures of the face every minute while the volunteer talked over the mobile phone for 20 minutes. The specification of the imaging system was as follows: Temperature resolution = 0.1$^{\circ}C$; Range of temperature measurement = 17～40$^{\circ}C$; Pixel size = 0.9mm ${\times}$ 0.9mm; Frame time = 2.6s; Active temperature of detector = 77$^{\circ}$K. The result showed that temperature of the ear region was increased during the phone call and the region of the temperature increase on the face was expanded as the phone call time increased. Further study is necessary to investigate the temperature rise analytically and quantitatively.

• 해양환경안전학회지
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• 제14권1호
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• pp.15-20
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• 2008

오염된 퇴적물은 연안의 생태계 파괴에 근본적인 원인이 되고 있음에 따라, 선진 외국에서는 1960년대부터 이러한 문제 해결을 위한 새로울 기술개발을 진행하여 오고 있다. 본 연구에서는 유기퇴적물 수거를 위한 시스템 설계 및 개발에 있어서 오탁확산에 의한 2차 오염을 방지하거나 최소화 할 수 있는 Pilot 규모 형태의 흡입식 펌프 준설 시스템을 설계 제작하였으며, 시스템의 성능시험을 통한 적용 가능성을 제시하였다. 시스템 최적화를 위하여 수치해석기법을 통한 퇴적물 수거 시스템의 형상에 대한 성능평가를 수행하고, 제작 시스템의 성능시험에 있어서는 시스템의 정지 상태와 이동 상태에서의 퇴적물 수거 성능에 대한 실험을 수행하였다. 본 연구를 통하여 해저 유기퇴적물의 상부만을 준설할 수 있는 시스템의 개발 가능성을 확인하였다.