• Korean journal of food and cookery science
• /
• v.11 no.1
• /
• pp.83-91
• /
• 1995

For the accurate interpretation and objective measurement of textural characteristics of fermented vegetables, first of all, the studies on the microstructure and chemical compositions of vegetable cell, and the changes in the textural properties of vegetables during salting, blanching and fermentation should be carried out. And the mechanical textural parameters were needed to compare with and analyze in relation to the sensory parameters. In this review, the thypical force-distance curves of fermented vegetables were obtained from the compression, cutting and puncture test. And it was showed that the compression force was a more effective textural parameter to express the hardness of fermented vegetables, and the sensory chewiness and toughness were related to the changes in cutting force. In the puncture test, the puncture force was related to the hardness and varied with the size and form of puncture probe; the changes in puncture force by small probe could express the decrease in hardness and crispness, whereas those by large probe could represent the changes in toughness. And the brittleness and crispness could be measured by the break point and the numbers of peak obtained from the force-distance curves.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.12 no.11
• /
• pp.904-913
• /
• 2002

In this study, a dynamic analysis of the reciprocating compression mechanism considering viscous friction force of a piston used in small refrigeration compressors is performed. The length of cylinder in this class of compressors is shortening to diminish the frictional losses of the piston-cylinder system. So, the contacting length between piston and cylinder liner is in variable with the rotating crank angle around the BDC of the reciprocating piston. In the problem formulation of the compression mechanism dynamics, the change in bearing length of the piston and all corresponding viscous forces and moments are considered in order to determine the trajectories of piston and crankshaft. The piston orbits for viscous friction model and Coulomb friction model were used to compare the effect of the friction forces of piston on the dynamic trajectories of piston. To investigate the effect of friction force acting on the piston for the dynamic characteristics of crankshaft, comparison of the crankshaft loci is given in both viscous model and Coulomb model. Results show that the viscous friction force of piston must be considered in calculating for the accurate dynamic characteristics of the reciprocating compression mechanism.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.20 no.44
• /
• pp.323-332
• /
• 1997

This study evaluated the compression force at the L5/S1 disc using EMG(Electromyography). EMG signals were analyzed under the condition of fixed vertical factor (20Cm∼80Cm), two horizontal factors (35Cm, 55Cm), and two weight factors (10Kg, 25Kg) 2 times per minute for each posture. Also, the result was compared with the compression force of each posture which computated by the equation of NIOSH(National Institute for Occupational Safety and Health) guide to manual lifting(1991). The experimental result show that EMG signals have more an effect on the Weight than the Horizontal factors. Also, there are not significant differences on the analysis result of EMG signals between Health members and not, because the body buildings which doing Health members are not enhanced the motor unit due to the MMH(Manual Material Handing).

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.371-376
• /
• 1996

The damping force of shock absorber in an automobile is determined by the components which construct the S/A. In this study we investigate the individual effect of these components on damping force. In addition, opening of important valve doling compression and tension cycle due to up-down reciprocation movement is also researched. Thus we are to strictly control the properties and tolerance of components having important effects on tile damping force and to produce S/A of better quality.

• 연구논문집
• /
• s.34
• /
• pp.87-99
• /
• 2004

A spring tension control device is used as a very important part of an twister system. The friction force of tensioner must keep same friction force during winding in package. For satisfy this function, many device used common compression coil spring. In this paper, by using the case-building technique which was based on simple theory that unknown design variables are induced by given input design variables by the designer, design automation algorithm about rectangular section compression springs with elastic characteristic is developed. Four design equation are justified in using of analysis of torsion of straight bar of rectangular section and geometrical condition of coil spring. Four design equation and nine design variables are computed by case-building technique.

• Journal of Advanced Marine Engineering and Technology
• /
• v.18 no.3
• /
• pp.63-67
• /
• 1994

A main property for fiber reinforced thermoplastic composite material in compression molding is the flow of fibers. This flow is so effective a long direction of acting force that this study examined for the inclined angel of 30$^{\circ}$, 45$^{\circ}$ and 6$^{\circ}$. Below the near softing temperature of plastic, the fiber has been fractured at a point so that the fiber strength is smaller then the local hydrostatic stress in the mold. It has been found that the position of fracture is changing accrding to the incling angle. In case of the above softing temperature, the larger the inclined is, the farther the flow of fiber move. Also the plastic flow has been progresed with the cicular are type.

• Journal of Institute of Control, Robotics and Systems
• /
• v.18 no.10
• /
• pp.964-969
• /
• 2012

Robot hands capable of grasping or handling various objects are important for service robots to effectively aid humans. In particular, controlling a contact force and providing a compliant motion are essential when the hand is in contact with objects. Many dexterous robot hands equipped with force/torque sensors have been developed to perform force control, but they suffer from the complexity of control and high cost. In this paper, a low-cost robot hand based on SEA (Series Elastic Actuator), which is composed of compression spring, stretch sensor, and wire, is proposed. The grasping force can be estimated by measuring the compression length of spring, which would allow the hand to perform force control. A series of experimentations are carried out to verify the performance of force control of the proposed robot hand, and it is shown that it can successfully control the contact force without any additional force/torque sensors.

• Korean journal of food and cookery science
• /
• v.2 no.2
• /
• pp.43-54
• /
• 1986

Back-pyun is a kind of rice cake made by steaming rice flour added sugar, water and salt and garnished with shredded chestnuts, dates, mushrooms and pinenuts. The Back-pyun has been widely used in Korean celebrations. This study aimed to compare and determine the effects on sensory characteristics and texture of Back-pyun 1) when the proportion of glutinous rice, added i.1 making Back-pyun, is 0%, 5%, 10%, 15%, 20%, 25% and 30% 2) then it reheated after storage for 0,24, 48 and 72 hours. Evaluation was conducted through sensory evaluation and objective evaluation. The results are as follows : 1. In sensory evaluation, color of Back-pyun turned yellow as the addition level of glutinous rice increased and then by reheating after storage for 24, 48 and 73 hours. Coarseness was not significantly different as the addition level of glutinous rice increased before storage. But Back-pyun reheated after storage for 24,48 and 72 hours were significantly different by the addition level of glutinous rice. Softness, dryness and crumblyness tended to decrease as the addition level of glutinous rice increased and by reheating after storage for 24, 48 and 72 hours. The most favorite tendency on the appearance was at the addition level of glutinous rice of 5%. Texture and overall preference were better at the addition level from 10% to 20% than any other levels. 2. Rheometer measurement indicated that compression force, gumminess ana chewiness tended to increase as the addition level of glutinous rice increased and decrease by the storage conditions. But work ratio and recovered height did not have much effect the addition level of glutinous rice and the storage conditions. Compression force of Back-pyun (not reheated) tended to increase by the storage time and the addition level of glutious rice. Especially it showed remakably increasing tendency during 24 hours storage (at $4^{\circ}C$) 3. Moisture content tended to increase by the addition level of glutinous rice and decrease by the storage time. But moisture content of Back-pyun reheated after storage for 24 hours stowed the increasing tendency. 4. Softness of Back-pyun had significant relationship with compression force and work ratio. Dryness and crumblyness had significant relationship with work ratio. Therefore compression force and work ratio represented the texture of Back-pyun.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.10a
• /
• pp.218.3-219
• /
• 2003

백편을 만들 때 멥쌀가루 100에 찹쌀가루를 총중량의 0%, 5%, 10%, 15%, 20%, 25%, 30% 첨가하고 저장시간 0시간, 24시간, 48시간, 72시간 저장한 후 (4$^{\circ}C$에서) reheating 한 백편의 기호성과 조직감(Texture)에 어떠한 영향을 끼치는 가를 관능검사와 기계적 검사에 의해 측정한 결과를 다음과 같이 요약할 수 있다 1. 관능검사 결과 백편의 Color 는 찹쌀의 첨가량이 증가할수록 누런색이 짙어졌으며, 24, 48, 72 시간 저장한 후 reheating 한 백편도 누런색이 짙어지는 경향을 나타냈다. Coarseness 는 찹쌀의 첨가량이 증가할수록 증가하는 경향이었으나 저장전의 백편은 유의적인 경향을 나타내지 않았다. 찹쌀의 첨가량이 증가할수록 Softness, Dryness, crumblyness는 감소경향을 나타냈으며 24, 48, 72 시간을 저장한 후 reheating 한 백편도 유의적인 감소경향을 나타냈다. 외관의 기호도는 찹쌀의 첨가율이 5% 인 백편을 가장 좋아했고, 조직감 및 종합적인 기호도는 찹쌀의 첨가율이 10~20%인 백편을 좋아했다. 2. Rhemeter에 의한 백편의 Texture는 찹쌀의 첨가량이 증가할수록 Compression force, gumminess, Chewiness가 증가하는 경향을 나타냈다. 24, 48, 72 시간 저장한 후 reheating 한 백편은 저장전보다 점점 감소경향을 나타냈다가 72시간 저장한 후 reheating 하면 다시 증가경향을 나타냈다. Work ratio 및 Recovered height는 찹쌀의 첨가량과 저장시간의 변화에 크게 영향을 미치지 않았다. Recovered 하지 않고 0, 24, 48, 72 시간 저장한 백편의 Compressing force는 찹쌀의 첨가량이 증가할수록 증가경향이 컸고 저장시간이 경과함에 따라 Compression force가 증가하였는데 특히 24시간 저장하는 동안 급격히 증가하였다. 3. 찹쌀 첨가량이 증가할수록 수분함량은 증가하였고, 저장시간이 경과함에 따라 수분함량은 감소경향을 나타냈으나 24시간 저장한 후 reheating 한 백편만이 수분함량의 증가경향을 나타내었다. 4. qoruvs의 Softness 는 Compression force 및 Work ratio 와 유의적인 상관관계를 나타내었으며, Dryness 와 Crumblyness 는 Work ratio와 유의적인 상관관계를 나타내고 있어 백편의 조직감은 Compression force 와 Work ratio로 대치할 수 있을 것이라고 사료된다. 수분함량은 기계적 검사보다 관능검사와 더욱 높은 상관관계를 나타냈다.

• Journal of radiological science and technology
• /
• v.26 no.2
• /
• pp.29-35
• /
• 2003

The purpose of this study was to compare the compression force and thickness of the compressed breast between mediolateral oblique and craniocaudal mammography. This population consisted of 204 paired mediolateral oblique and craniocaudal mammography obtained on one mammographic unit by certified mammography technologists during 2 month period. The women examined were $30{\sim}59$ years old with breast implants, the patients were classified into 3 groups according to age, $30{\sim}39$, $40{\sim}49$, and $50{\sim}59$, prior breast cancer, mastectomy or breast deformity were excluded. The digital readout of compressed breast compression force and thickness was recorded. Mammographic positioning was assessed using standard criteria. The mean compression force of the compressed breast on the craniocaudal projection was less than the mean compression force on the mediolateral projection(14 versus 13.88 daN, p<0.05). The mean thickness of the compressed breast for mediolateral projection was 41.46 mm and that for the craniocaudal projection was 39.50 mm(p<0.05). The compressed breast is higher or thicker on mediolateral oblique than on craniocaudal mammography.