• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.221-224
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• 1996

Since impact phenomenon is highly nonlinear, the analysis and control of the contact motion has been a challenging subject. Various researches have been carried out mostly for the contact of a rigid robotic manipulator with a stiff and elastic environment. This paper is motivated by a new contact task: the in-circuit test of a printed circuit board. In this process, high speed contact occurs between a rigid probing manipulator and a plastically deformable work environment. A new dynamic model of the impact controlled probing task has been proposed, considering contact with the plastically deformable object. Approaching velocity conditions to avoid an excess of the allowable penetration depth and control the generated impact force properly are derived from the proposed model. The results of the simulation studies are made for various probing conditions and show the validity of the proposed model.

• Journal of Satellite, Information and Communications
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• v.11 no.3
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• pp.51-57
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• 2016

Many kinds of telemetry should be monitored to check the state of spacecraft and it leads the time consumption. However, it is very important to define the status of satellite in short time because the contact number and time of low earth orbit satellite is limited. Also, on-board fault management should be prepared for non-contact operation because of the sever space environment. In this paper, on-board and ground autonomous operation method for the safety enhancement is described. Immediate fault detection and response is possible in ground by explicit anomaly detection through satellite event and error information. Also, satellite operation assistant system is proposed for ground autonomy that collect event sequence in accordance with related telemetry and recommend or execute an appropriate action for abnormal state. Critical parameter monitoring method with checking rate, mode and threshold is developed for on-board autonomous fault management. If the value exceeds the limit, pre-defined command sequence is executed.

• Journal of the Korea Furniture Society
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• v.13 no.1
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• pp.42-47
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• 2002

The folding chairs are one of the most necessary furniture for satisfying the moderns' wants which is utilized for limited space rationally. These folding chairs are variously used in interior spaces such as offices, dining areas, and resting areas. They are very easy to move around, so that quiet useful in out door areas, too. Moreover, they play an important role in public spaces as supplementary furniture. The folding chairs have one or several axes, and they are classified according to type of axes like below. 1. Method of divide seating board into 2 and fold, 2. Method of folds seating board and lay on bottom of backboard, 3. Method of fold back board and lay on top of seating board, 4. Method of fold into contact with left and right, 5. Method of gathering legs into one and fold. The folding chairs have to be easy to operate, firm and safe, light for moving around easily, designed for able to change units whenever they have damaged. Change of residential spaces according to the trend towards the nuclear family maximized necessity of limited spaces' use. Therefore, this study provides insights for development of new methods' of folding chairs.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.349-353
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• 2008

This study was performed to determine the adherence rates of standard type Salmonella Typhimurium (ST) and wild type Salmonella spp.(WT) in pork after the following contact types and times at $10^{\circ}C$: pork meat (2, 6, 24 hr), conveyer belt (2, 6 hr), stainless steel (2, 6 hr), and cutting board (2, 6 hr). After 6 hr of pork meat to meat fat contact, the adherence rates for ST and WT were approximately 4.21 and 26.87%, respectively, and after 6 hrs of pork meat to red meat contact they were 16.40 and 27.48%, respectively. However, after 24 hr of both types of contact, ST and WT showed 100% adherence rates. The adherence rates for ST after 2 hr and 6 hr of pork meat to conveyer belt contact were 1.34 and 0.60%, respectively, while the adherence rate for WT was 5.14% after 6 hr of contact. After pork meat to stainless steel contact, ST showed adherence rates of zero and 1.59% after 6 and 24 hr of contact, respectively, while the adherence rates for WT ranged from 0.17% after 2 hr to 5.01% after 6 hr. On the other hand, neither ST nor WT offered adherence data following pork meat to cutting board contact. These results suggest that the adherence rates of ST and WT after pork meat to pork meat contact or pork meat to processing surface contact were significantly affected by the contact time and WT presented much higher adherence rates for both types of transmission than ST.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.1
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• pp.61-66
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• 2016

In order to improve the bonding efficiency of starch adhesives and water resistance of corrugated board, mixing ratio of additives dosage was changed and its effects were analyzed. When the additives dosage was increased, bonding strength, vertical compression strength, bursting strength and water resistance were increased, because of hydroxyl groups or acetyl groups in starch adhesives and cellulose fibers of corrugated board were cross-linked by additives. When 1.0% glyoxal dosage was added, flat crush strength and vertical compression strength were increased. With 1.5% glyoxal, bonding strength and bursting strength were increased. However, 2.0% glyoxal dosage was added, most of strength except bursting strength were decreased. Thus, when the appropriate amount of additives are added during corrugated board production process, increased bonding efficiency of starch adhesives and higher water resistance of corrugated board can be achieved.

• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.119-127
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• 2005

The purpose of this research helps to make full use for perfect performance by grasping the defects of Ropez motion performed by athlete CSM who was under the training for the 28th 2004 Athene Olympic Garnes, and by presenting complementary methods. For the better Ropez motion which had been performed by CSM for the 1st dispatch selection test and the final for the 28th Athene Olympic Game was analyzed with 3-dimensional cinematographic method. Here are the conclusions: 1. During the board contact phase, powerful kicking and rapid forward flexion motion of upper body make increasing vertical velocity of C. O. G and enlarging body angle. 2. It was indicated that rapid forward flexion motion of upper body during the board contact phase get a large body angle in horse take-off. 3. rapid forward flexion motion of upper body during the board contact phase makes a longer time at horse contacting phase. It showed that this result increased velocity of horse take-off causing by powerful blocking motion. 4. Increasing of air-borne height during pre- flight phase, makes a higher C. O. G; and larger angle of hip, angle of knee and body angle in the landing phase. And it revealed that these results have a stable landing.

• Design & Manufacturing
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• v.10 no.1
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• pp.19-25
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• 2016

Connectors are very important components that transmit electric signals to different parts. It must maintain intensity of the connector to prevent defects from impact and maintain contact to transmit electric signals. Most of the external parts of the connector, which act as the main framework, are formed by injection molding. However, bend deformation occurs for injection molded products due to the residual stress left inside the product after product molding. When the bend deformation is large, it does not come into complete contact when being assembled with other parts, which leads to connector contact intensity not being properly maintained. In result, the main role of the connector, which is to transmit electric signals, cannot be performed. In order to address this problem, this study conducted bend deformation cause analysis through bend deformation analysis to predict and prevent bend deformation of housings and wafers, which are injection molded products of pressure welded connectors that are normally applied in compact mobile and display products. Bend deformation analysis was carried out by checking the charging time, pressure distribution and temperature distribution through wire to board connector wafer and housing injection molding analysis. Based on the results of the bend deformation analysis results, the cause of the bend deformation was analyzed through deformation resulting from disproportional cooling, deformation resulting from disproportional contraction, and deformation resulting from ingredient orientation. In result, it was judged that the effects for bend deformation were biggest due to disproportional contraction for both the pressure welded connector wafer and housing.

• Journal of the Microelectronics and Packaging Society
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• v.31 no.2
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• pp.9-15
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• 2024

The effect of the residual impurity on the prepreg surface on the wettability of encapsulant for chip on board package was analyzed with microstructure, compositions and chemical bonds using a scanning electron microscope and X-ray photoelectron spectroscopy. As a result, the contact angle of w/ residual impurity sample was measured to be 28° higher than that of w/o residual impurity sample, and the C-O bond was decreased to be 4% lower than that of w/o residual impurity sample. The surface energy of the prepreg decreased because the impurity ions, Na and F, generated by the manufacturing process and wet etching, reacted chemically with the C on the prepreg surface, forming C-F bonds and breaking the C-O bonds on the prepreg surface. Therefore, the wettability of the encapsulant was degraded because the contact angle between the encapsulant and the prepreg was increased.

• Journal of Korean Physical Therapy Science
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• v.18 no.4
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• pp.59-64
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• 2011

Purpose : The purpose of this study was to evaluate the effects of the stretching of the calf muscles on foot pressure and contact area in young adult. Participants stood on a wedge board that was sloped between 15~25 degree for 15min. After stretching participants stood quietly on force plate, result was recorded. Participants stood on a force plate for 1 min in eye closed condition, and them the foot pressure and area was recorded. The following variables were calculated off-line: anterior and posterior foot pressure and contact area, medial and lateral foot pressure and contact area. Results showed that anterior pressure change due to stretch, but mediolateral was not significant. This result suggested that stretching of the calf muscle has the effect of increasing anterior pressure by flexibility change on calf muscle, so this effects might be effective intervention for reduce of serious problem to neurologic patients in therapy session.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.81-98
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• 2003

The purpose of this study is to closely examine kinematic characteristics by jump phase of Li Xiaopeng motion in horse vaulting and provide the training data. In doing so, as a result of analyzing kinematic variables through 3-dimensional cinematographic using the high-speed video camera to Li Xiaopeng motion first performed at the men's vault competition at the 14th Busan Asian Games, the following conclusion was obtained. 1. It was indicated that at the post-flight, the increase of flight time and height and twisting rotational velocity has a decisive effect on the increase of twist displacement. And Li Xiaopeng motion showed longer flight time and higher flight height than Ropez motion with the same twist displacement of entire movement. Also the rotational displacement of the trunk at peak of COG was much short of $360^{\circ}$(one rotation) but twist displacement showed $606^{\circ}$. Likewise, Li Xiaopeng motion was indicated to concentrate on twist movement in the early flight. 2. It was indicated that at the landing, Li Xiaopeng motion gets the hip to move back, the trunk to stand up and the horizontal velocity of COG to slow down. This is thought to be the performance of sufficient landing, resulting from large security of rotational displacement of airborne and twist displacement. 3. It was indicated that at the board contact, Li Xiaopeng motion made a rapid rotation uprighting the trunk to recover slowing velocity caused by jumping with the horse in the back, and has already twisted the trunk nearly close to $40^{\circ}$ at board contact. Under the premise that elasticity is generated without the change of the feet contacting the board, it will give an aid to the rotation and twist of pre-flight. Thus, in the round-oH phase, the tap of waist according to the fraction and extension of hip joint and arm push is thought to be very important. 4. It was indicated that at the pre-flight, Li Xiaopeng motion showed bigger movement than the techniques of precedented studies rushing to the horse, and overcomes the concern of relatively low power of jump through the rapid rotation of the trunk. Li Xiaopeng motion secured much twist distance, increased rotational distance with the trunk bent forward, resulting in the effect of rushing to the horse. 5. At horse contact, Li Xiaopeng motion makes a short-time contact, and maintains horse take-off angle close to vertical, contributing to the increase of post-flight time and height. This is thought to be resulted from rapid move toward movement direction along with the rotational velocity of trunk rapidly earned prior to horse contact, and little shave of rotation axis according to twist motion because of effective twist in the same direction.