• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.682-686
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• 2001

A fundamental structural design consideration for a vehicle is the overall vibration characteristics in bending and torsion. Vibration characteristics of a vehicle system are mainly influenced by dynamic stiffness of the vehicle body structure and material and physical properties of the components attached to the vehicle body structure. The first step in satisfying this requirement is to obtain a satisfactory dynamic model of the vehicle structure. In this paper. modeling techniques of the vehicle components are presented and the effects of the vehicle components on the vibration characteristics of the vehicle are investigated,

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1706-1709
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• 2003

This paper demonstrates a unique method for measuring vehicle states such as body sideslip angle and tire sideslip angle using Global Positioning System(GPS) velocity information in conjunction with other sensors. A method for integrating Inertial Navigation System (INS) sensors with GPS measurements to provide higher update rate estimates of the vehicle states is presented, and the method can be used to estimate the tire cornering stiffness. The experimental results for the GPS velocity-based sideslip angle measurement. From the experimental results, it can be concluded that the proposed method has an advantage for future implementation in a vehicle safety system.

• Smart Structures and Systems
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• 제15권6호
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• pp.1439-1461
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• 2015

Design criteria, modeling rules, and analysis principles of seismic isolation systems have already found place in important building codes and standards such as the Uniform Building Code and ASCE/SEI 7-05. Although real behaviors of isolation systems composed of high damping or lead rubber bearings are nonlinear, equivalent linear models can be obtained using effective stiffness and damping which makes use of linear seismic analysis methods for seismic-isolated buildings possible. However, equivalent linear modeling and analysis may lead to errors in seismic response terms of multi-story buildings and thus need to be assessed comprehensively. This study investigates the accuracy of equivalent linear modeling via numerical experiments conducted on generic five-story three dimensional seismic-isolated buildings. A wide range of nonlinear isolation systems with different characteristics and their equivalent linear counterparts are subjected to historical earthquakes and isolation system displacements, top floor accelerations, story drifts, base shears, and torsional base moments are compared. Relations between the accuracy of the estimates of peak structural responses from equivalent linear models and typical characteristics of nonlinear isolation systems including effective period, rigid-body mode period, effective viscous damping ratio, and post-yield to pre-yield stiffness ratio are established. Influence of biaxial interaction and plan eccentricity are also examined.

• 패션비즈니스
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• 제15권5호
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• pp.103-114
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• 2011

During a wearer's movement, the apparel fabric layers collide each other in a highly complicated manner. The collision involves cloth-cloth, and cloth-body collision. The diversity of the textile fabrics, including silk, wool, cotton, and other synthetic fibers, together with the complex details of the apparel construction, makes the collision and other calculation procedure involved in the 3-dimensional clothing software system much more complicated. Therefore, there is a need to measure the behavior of the fabrics during the fabric collision cycles. In this study, as a first step, static measurements pertinent to the factors governing the appearance of the apparel fabrics were implemented. The drape profile, stiffness(Sd and Sf), tensile properties, thickness, and the air permeability were measured. The correlation between the parameters were calculated and reviewed. It is found that there is a high correlation of 0.97 between the actual fabric drape parameters and the 3D virtual fabric drape parameters. The measured drape coefficients of the fabrics show relatively good correlation with the measured fabric stiffness.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.247-248
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• 2018

In order to secure the variability of long-life housing, dry walls are used. The composite gypsum board panel is the most frequently used infill system for the wall, and it is an excellent construction method in terms of constructability and economic feasibility. However, there are also problems such as the destruction of Ondol pipes at the bottom floor and being unable to fix the light weight steel frame (M-bar) when a variable composite gypsum board panel is used. To solve such problems, a wall with a method of fixing only the top part without fixing the bottom floor is developed, but it is difficult to identify the durability of ceiling frame according to the tensile force of stud and the safety according to the Stiffness and impact resistance (soft body) of ceiling frame. Therefore, this study verified the effectiveness of infill system for the wall by conducting experiment on the stiffness and impact resistance of composite gypsum board panel according to the reinforcement of ceiling frame (wooden frame, double saw-toothed bracket, Cross M-bar). As a result, it was possible to secure the safety of wooden frame while the impact resistance and the Stiffness of double saw-toothed bracket and cross M-bar were not secured.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 추계학술대회논문집; 한국과학기술회관; 6 Nov. 1997
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• pp.36-42
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• 1997

A prototype of 500Wh class flywheel energy storage device was designed and manufactured to check the previously predicted system performance. The system was intentionally designed to show rigid body behavior up to the maximum operating speed of 60000Tpm and to have its 2nd rigid critical mode, of which nodal point lies on the flywheel center of mass, around 4000 to 6000rpm with radial magnetic bearing stiffness of l.e+6 N/m. Numerous experiments an the system behavior showed that the PM axial bearing, designed utilizing a commercial code, acts as resonably as predicted and, most importantly, the system becomes stable after the 2nd critical speed. The EM radial bearing, however, was found out to have orthotropic property with much less radial stiffness values than expected, so that it was observed that the 2nd forward and backward critical modes were excited at 310 and 590rpm respectively with larger vibration amplitudes. Thus, in order to improve the system dynamic behavior, the EM radial bearing is currently being re designed so as to get bigger stiffness and, in turn, smoother operation of the system.

• 대한한의학원전학회지
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• 제30권1호
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• pp.211-221
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• 2017

Objectives : The practices of Wei-qi and Nutritive-qi are generally divided into external Mai and internal Mai. However, they are closely interrelated and practiced together. While taking these aspects into consideration, this paper attempts to make interpretations in relation with Nutritive-qi the disease pathogens that appear in Shanghanlun's disease symptoms. Methods : Using the practice and function of Nutritive-qi described in Huangdineijing, the paper shall make interpretations for the patterns of Mawhangtang, patterns of Gaejitang, and the pathologies of pain, oedema, and nosebleed as described in Shanghanlun. Results & Conclusions : The pain from the patterns of Gaejitang differ from that of the patterns of Mawhangtang. First, the pain from the the patterns of Gaejitang cannot be the main symptom. Even if there is a symptom of pain, it's severity is not serious. Second, the pain from the patterns of Gaejiang takes the form of stiffness, and not general bodily pain. The reason for this stiffness is because of the emptiness of Wei-qi that leads to the congestion of Nutritive-qi which in turn causes the lack of qi and blood flow in muscula area such as abdomins. The symptom of oedema where one's body becomes swollen comes from a number of pathogens. First, the flow of meridian becomes hindered due to external dampness, a character which tends to be adhesive when added with humidty, and this results in the blockage of water qi which then causes the coagulation of nutritive blood. Second, when toxic heat is repressed and blocked within the lesser-yang channel, lesser-yang meridian stops working, which causes nutritive blood to clog at the front and back of ears since lesser-yang channel flows through that portion of body. Third, although oedema is not specifically mentioned in the sentences, but there exists the patterns of Daechungyongtang where water lumps are formed due to the accumulation and blockage of watery dampness. The patterns of Daechungyongtang is cuased when meridian is hindered from externally discharging body fluid due to a problem with meridian that blocks the fumigated internal heat which turns into bodily fluid from being discharged externally.

• The Journal of Korean Physical Therapy
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• 제30권4호
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• pp.135-140
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• 2018

Purpose: This study aimed to determine the appropriate stimulus strength that could result in a positive effect on the ankle joint spasticity when patients with chronic stroke performed whole body vibration (WBV) exercise. Methods: Among 72 patients who were diagnosed with stroke at least 6 months ago, those able to perform a half squat pose with ambulation issues due to ankle joint spasticity (modified Ashworth scale, $MAS{\geq}2$) were included for analysis. Individuals participated in four different frequencies of vertical WBV exercise; 0 Hz, 10 Hz, 20 Hz, and 30 Hz. Vibration amplitude was 3-4 mm and 5 minutes WBV exercise was performed at each frequency, followed by a measurement after 2-minute rest. We assigned 18 individuals to each frequency and asked them to participate in the WBV exercise once every 3 weeks. The level of spasticity was evaluated by visual analogue scale (VAS) for self-assessment. The myoton PRO was utilized to objectively evaluate the level of spasticity and check the muscle tone and stiffness. Results: Participants showed 0 Hz VAS was a significant difference between 20 Hz application conditions (p<0.05). Muscle tone was significantly different at 0 Hz between 20 Hz, and 30 Hz (p<0.05), significantly difference at 10 Hz between 30 Hz (p<0.05). Muscle stiffness significantly difference at 0 Hz between 20 Hz, and 30 Hz (p<0.05), significantly difference at 10 Hz between 20 Hz, and 30 Hz (p<0.05). Conclusion: Findings of this study show that the frequency of more than 20 Hz was effective in improving the ambulatory ability in patients with chronic stroke. Currently, the effective WBV protocol is limited. Hence, this study was designed to suggest an effective WBV protocol to improve neuromodulation ability for chronic stroke patients.

• International Journal of Human Ecology
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• 제16권2호
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• pp.1-9
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• 2015

This study investigated the effects of persimmon-dyed clothing materials upon thermophysiological responses and subjective comfort sensations during exercise and rest in a warm environment. Six healthy, untrained women participated in two separate testing sessions, with cotton materials dyed with astringent persimmon extract (DC) and undyed cotton materials (UDC). The physical characteristics associated with heat and moisture transfer were improved in DC; also, stiffness, anti-drapery stiffness and crispness in the primary hand values were higher in DC. The experimental protocol consisted of a 10-min rest, 15-min exercise on a treadmill (at ${7km{\cdot}h^{-1}}$) and 25-min recovery at $28{\pm}0.2^{\circ}C$ and $50{\pm}3%\;RH$. The results were as follows: When wearing DC rather than UDC, mean body temperature, heart rate, heat storage and body mass loss were significantly lower during the whole experimental period. Clothing microclimate temperature showed different profiles between the two clothing materials, being lower with DC than UDC during the first half of exercise and the second half of recovery. Clothing microclimate humidity was significantly lower with DC than UDC during the whole experimental period. When wearing UDC, subjects felt significantly warmer and less comfortable during exercise, and sensed greater humidity during exercise and recovery. These results suggest that eco-friendly clothing materials dyed with astringent persimmon extract can reduce exercise-induced heat load and improve subjective sensations when exercising and resting in a warm environment, due to greater heat dissipation from the body to the outside environment compared with undyed clothing materials.

• 대한기계학회논문집 C: 기술과 교육
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• 제5권2호
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• pp.89-95
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• 2017

제품을 개발하는데 있어서 경량화와 원가절감이라는 두가지 요소는 가장 중요한 화두이다. 특히 대형 LCD 로봇은 최대 $3{\times}3m$ 이상의 글라스를 7m 높이까지 상하, 전후로의 직선운동과 선회축을 중심으로한 회전운동을 하면서 작업공정간 이송을 가능케 하는 대형 구조물이다. 따라서 지나치게 무거울 경우에는 클린룸내 설치에 문제가 있을 수 있고 반송물의 정확한 이송을 위하여는 고강성이 요구되며 대량 생산을 위한 연속작업을 충분히 감당할 수 있는 내구강도를 확보하여야 한다. 따라서 경량화, 고강성, 고강도 제품에 대한 요구는 갈수록 증가하고 있다. 현재 개발되고 있는 11 세대 대형 LCD 승강프레임은 이러한 요구조건을 충족하기 위하여 최적설계 기법을 적용하여 기존 제품 대비 경량화와 고강성 요구조건을 만족하였으며 용접부에 대한 상세 수명평가로 내구강도에 대한 신뢰성을 확보하였다.