• 전자공학회논문지B
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• 제29B권3호
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• pp.25-34
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• 1992

This paper proposes a Self-Tuning control algorithm for tracking the reference trajectory by measuring the end-point of robot manipulator whose links are light and flexible, and the performance of it is tested through the computer simulation. As an object of system, a flexible robot manipulator with two-links is considered and an assumed mode shape method including gravity force is adopted to analyze the vibration modes for each links and dynamics equation is derived. The controller is designed as a combined form which consists of dynamic feedforward compensator and self-tuning feedback controller. The one supplies nominal torque and the other supplies variational torque to manipulator. Apart from the, K-incremental predictor is also proposed in order to eliminate the offset error. and it shows that the result of simulation adapted well to load change and rapid velocity.

• 한국기계가공학회지
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• 제19권7호
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• pp.67-73
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• 2020

Shrinkage is inevitable in the curing of resins during the nanoimprint process. The degree of shrinkage that occurs as the resin transforms from a viscous liquid to solid differs depending on the type of resin. However, if the cured material is repeatedly cured using the same material, constant shrinkage can be confirmed. In this study, the pattern of change was observed by repeatedly performing the nanoimprint process using a resin with a constant shrinkage rate. The observed pattern for the change of shape was made using a triangular pyramid-shaped aluminum master mold and a flexible replica mold made from the master. Shrinkage that results from the nanoimprint process occurs linearly in the longitudinal direction of the pattern and can be predicted by simple calculations. The change of the pattern due to shrinkage occurred as expected. If the shrinkage rate remains constant, various patterns can be manufactured with high accuracy by correcting these changes before producing a specific shape. This study confirms that the pattern of the desired angle can be obtained by performing the repeated imprint without having to manufacture a master mold.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.312-318
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• 2001

This paper suggests the finite element method to analyze the dynamic characteristics of a rotating HDD system including the supporting structure with general shape. The flexible supporting structure was modeled by tetrahedra elements to produce a finite element model of disk-spindle-shaft-housing system and the dynamic characteristics of the HDD system was investigated due to the change of rotating speed. The validity of the presented method was verified by the modal testing. The supporting structure has an crucial effect on lower modes for HDD system, so that it is required to consider the supporting structure to accurately analyze the dynamic characteristics of HDD system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.307-310
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• 1997

In case of environment requiring safety such as human body and requiring flexible shape, a conventional mechanical actuator system does not satisfy requirement. Therefore, in order to solve this problem, a research of various smart material such as EAP (Electro Active Polymer), EAC (Electro Active Ceramic) and SMA (Shape Memory Alloy) is in progress. Recently, the highest preferring material among various smart material is EP (Electrostictive Polymer), because it has very fast response time, poerful force and large displacement. The previous researches have been studied properties of polymer and simple control, but present researches are studied a polymer actuator. An EP (Electostrictive Polymer) actuator has properties which change variably as shape and environmental condition. Therefore, in order to coincide with a user's purpose, it is important not only to decide a shape of actuator and mechanical design but also to investigate a efficient controller. In this paper, we constructed the control logic with an adaptive fuvy algorithm which depends on the physical properties of EP that has a dielectric constant depending on time.

• Design & Manufacturing
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• 제14권3호
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• pp.23-30
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• 2020

Laser Assisted Thermo-Compression Bonding (LATCB) has been proposed to improve the "chip tilt due to the difference in solder bump height" that occurs during the conventional semiconductor chip bonding process. The bonding module of the LATCB system has used a piezoelectric actuator to control the inclination of the compression jig on a micro scale, and the piezoelectric actuator has been directly coupled to the compression jig to minimize the assembly tolerance of the compression jig. However, this structure generates a lateral force in the piezoelectric actuator when the compression jig is tilted, and the stacked piezoelectric element vulnerable to the lateral force has a risk of failure. In this paper, the optimal design of the flexure hinge was performed to minimize the lateral force generated in the piezoelectric actuator when the compression jig is tilted by using the displacement difference of the piezoelectric actuator in the bonding module for LATCB. The design variables of the flexure hinge were defined as the hinge height, the minimum diameter, and the notch radius. And the effect of the change of each variable on the stress generated in the flexible hinge and the lateral force acting on the piezoelectric actuator was analyzed. Also, optimization was carried out using commercial structural analysis software. As a result, when the displacement difference between the piezoelectric actuators is the maximum (90um), the maximum stress generated in the flexible hinge is 11.5% of the elastic limit of the hinge material, and the lateral force acting on the piezoelectric actuator is less than 1N.

• 소음진동
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• 제7권2호
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• pp.261-272
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• 1997

Recently washing machines are to be in lower vibration and lower sound because of better environment. Vibration problems in washing machines occur in both washing mode and spinning mode, but vibration in spinning mode becomes main problem because of its high rotating speed and continuity. Vibration while spinning is mainly due to rigid body motion of total washing system which includes suspending rods, washing bath, spinning bath, and gear sets. In this study, some researches were done in order to analyze the rigid body motion of washing system and flexible vibration of spinning bath. A basic mathematical model was established, and the effect of position of salt water and shape change of salt water case were considered. And the effect of lengths of suspending rods, attaching angles, vertical and horizontal position, stiffness of spring on the change of vibration were also considered. To identify the effect of salt water on vibration, some measurements were done. When salt water was positioned at upper part, the effect was most and this coincides with the tendency of simulation.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.726-728
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• 2016

본 연구에서는 leap motion을 이용하여 실시간 MIDI controller를 설계하였다. Windows상에서 virtual MIDI port를 생성한 후 DAW(Digital Audio Workstation) 또는 VST(Virtual Studio Technology)와 해당 port와 프로토콜에 연결되어 통신을 수행한다. MIDI controller는 손동작 및 모양을 실시간으로 탐지해서 해당 데이터를 MIDI 데이터로 변환시킨다. 이 변환 된 데이터는 설정 된 포트와 미리 입력 된 MIDI CC(Control Change)에 따라 전송된다. 따라서 기존의 MIDI controller보다 유연한 MIDI 입력을 지원하는 목적을 가진다.

• 한국실내디자인학회논문집
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• 제16권6호
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• pp.77-85
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• 2007

The space where one's body lives is not only a space as the simple environment that is built with the physical factors, but also a space experienced by a movement accompanied by the concept of body perception including mental activities. In this study, the importance of the body is recognized and the meaning of the space of body perception including mental activities is understood. In this manner, the spatial unfolding phase and expression features are to be investigated through a standard of "What do they change?" by grasping those as a flexible space that changes spatial recognition. The following results have been drawn in this study; First, the application of the flexible concept in the space can give rise to the activities of an experiencing person in terms of being the object of spatial experience and appreciation. Also, the application changes a slightly static concept into a relative and dynamic space by introducing the movement. Second, the establishment of a space by a human's movement is accompanied by all perceptions and enables to perceive the space shape, the space itself and mutual communication between the spaces. Third, the expression of the human's movement in the fixed form of space lies in the extension of the fused spacial area with an observer beyond the physical spatial limitation. As human body intervenes in space, the meaning of the space has become more abundant and diverse and the space will be presented as the arena for sensitive and flexible communication as a responsive space that corresponds.

• 복식
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• 제56권7호
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• pp.115-125
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• 2006

The study on plane composition in clothing was focused mainly on woven wear earlier but its application has been reaching the knit wear. This study is confined to the utilization with geometrical linear pattern in the modern apparel. The work here intends to grasp the plane structure found in both woven wear and knit wear and, in particular, to understand the aesthetics of fashion. The modern flat patterned clothing has been affected by the oriental style or postmodernism in view of social and cultural aspect while its fabric material and expression method shows the diversity in terms of industrial and technical aspect. It can be characterized as several outstanding patterns: the geometrical pattern in structure, the linear pattern with seam line and 2-dimensional plane pattern without seam line, and the flexible silhouette integrated into one single shape with human body unlike the traditional apparel The aesthetics of fashion in modern flat patterned clothing can be divided into such category as the organically spatial change, the re-creation of tradition and the non-format framework. The organically spatial change shows the geometrical formation in clothes due to change in dimension, where the organically changing uniformity and generosity appears as the dimension progresses. The timeless without any difference of up and down, left and right, and inside and outside and the discontinuity due to limitless spatial change are also imbedded. The re-creation of tradition tells the reshaped spirits of old tradition by integrating and modifying the hereditary features in the old customed clothing into modern clothing. The modern flat patterned clothing implies the contemporaneousness or the frame through which the old and modern cultures may be shared and indicates the re-creation of the past and uniformity. The non-format framework contains the uncertainty in meaning and it doesn't have any certain standards. As both the apparel and the human body with this style aim at the open space, the numerous contingencies are realized.

• 대한기계학회논문집A
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• 제20권9호
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• pp.2812-2818
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• 1996

A cantilever beam with a mass and a spring at the end can be use to model a miniature flexible arm. It is necessary to know the natural frequencies and mode shapes to discuss its free vibration, especially when modal analysis is employed. A beam is clamped-free. In this paper we look at the lateral vibration of beams that have step changes in the properties of their cross sections. The frequency equation is derived by Bernoulli-Euler formulation and is sloved by the separation of variable. The parameters of the beam, 'mass and spring stiffness' are defined as nondimensionalized parameters for wide application of the results. According to the change of eigenvalues and mode shape are presented for this beam. The results presented are the eigenvalues and the natural frequencies for the first three modes of vibration. Results show that the parameters have a significant effect on the natural frequency.