• Title/Summary/Keyword: force measurement

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A STUDY ON ACCURACY OF MAXILLARY REPOSITIONING BY EXTERNAL MEASURING TECHIQUE (외부계측법에 의한 상악골 이동의 위치적 정확도에 대한 평가 연구)

  • Park, Hyung-Sik;Cha, In-Ho;Park, Hyung-Rae
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.13 no.1
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    • pp.44-52
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    • 1991
  • Internal measurement technique has been commonly and classically used to guide down-fractured maxilla by Le Fort I osteotomy into its new position during intraoperative procedure for correlating preoperative model works with surgery. However, It has been challenged now by several authors due to some problems as its inaccuracy in three-dimensional changes at surgery, difficulty to measure during surgery and impossibility of rechecking at the end of surgery etc. The purpose of this study was to evaluate the accuracy of maxillary movement by external measuring technique and to determine its accuracy between the prediction tracing and a new maxillary position. The results indicate that the external measuring technique was predictable in the vertical, horizontal and transverse change of the maxilla as its prediction, however, it has a tendency to shift the maxilla more anterior and inferior in overall direction than prediction. Post-operative canting difference were mimic, however Ehange of the maxillary dental midline was large and had a right-shifting tendency.1 The precise methods to keep maxillary dental midline as same as prediction and the avoidance of uneven force applied to the mandible for autorotation should be necessary during surgery in use of external measurement technique.

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Measurement of EMC/PCB Interfacial Adhesion Energy of Chip Package Considering Warpage (휨을 고려한 칩 패키지의 EMC/PCB 계면 접합 에너지 측정)

  • Kim, Hyeong Jun;Ahn, Kwang Ho;Oh, Seung Jin;Kim, Do Han;Kim, Jae Sung;Kim, Eun Sook;Kim, Taek-Soo
    • Journal of the Microelectronics and Packaging Society
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    • v.26 no.4
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    • pp.101-105
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    • 2019
  • The adhesion reliability of the epoxy molding compound (EMC) and the printed circuit board (PCB) interface is critical to the quality and lifetime of the chip package since the EMC protects PCB from the external environment during the manufacturing, storage, and shipping processes. It is necessary to measure adhesion energy accurately to ensure product reliability by optimizing the manufacturing process during the development phase. This research deals with the measurement of EMC/PCB interfacial adhesion energy of chip package that has warpage induced by the coefficient of thermal expansion (CTE) mismatch. The double cantilever beam (DCB) test was conducted to measure adhesion energy, and the spring back force of specimens with warpage was compensated to calculate adhesion energy since the DCB test requires flat substrates. The result was verified by comparing the adhesion energy of flat chip packages come from the same manufacturing process.

Numerical Analysis of the Stability of a High-Strength Joint Buried Pile Retaining Wall Method (수치해석을 이용한 고강도 결합 매입말뚝 흙막이 공법의 안정성 검토에 관한 연구)

  • Hyeok Seo;Yeongpan Ha;Junyoung Choi;Kyungho Park;Daehyeon Kim
    • The Journal of Engineering Geology
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    • v.34 no.2
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    • pp.249-262
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    • 2024
  • Retaining walls are widely used in the construction of underground structures. This study reviews the stability of the high-strength joint buried pile method at a site in Korea. [Consider giving details of the location.] The method is assessed by considering the amount of ground settlement, as calculated by finite element analysis and measured at the site. Comparison of the measured and numerical results confirmed the method's stability and field applicability. Settlement of 13.42~13.65 mm was calculated for seven cross-sections [The Abstract should be comprehensible without reference to the main text. The labels A-A' to G-G' should not be introduced here without explanation.] using numerical analysis, and the measured settlement reached a maximum of 2.00 mm. The observed differences and variations [Please state what differed/varied.] did not exceed the design expectations in any section. Instruments installed at the back of the excavation area were used to assess the conditions. An underground gradient meter recorded a cumulative horizontal displacement of between -0.40 and 0.60 mm, and an underground water meter recorded slight displacements of between -0.21 and 0.28 m compared with the initial measurements. A surface settlement meter observed very little movement, with a maximum of -2.00 mm compared with the initial measurement, thereby confirming the establishment of a stable state within the management criteria.

Performance Evaluation of High Strength Lattice Girder by Structural Analyses and Field Measurements (구조해석과 현장계측에 의한 고강도 격자지보재의 성능 평가)

  • Lee, Jeo-Won;Min, Kyong-Nam;Jeong, Ji-Wook;Roh, Byoung-Kuk;Lee, Sang-Jin;Ahn, Tae-Bong;Kang, Seong-Seung
    • The Journal of Engineering Geology
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    • v.30 no.3
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    • pp.237-251
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    • 2020
  • This study examined structural analysis of supports in tunnel and displacement and underground stress of tunnel by measurement, in order to evaluate the performance of high-strength lattice girders developed as a substitute for H-profiles. According to the three-dimensional nonlinear structural analysis results of the tunnel support, the load and displacement relationship between the H-profiles and the high-strength lattice girders showed almost the same behavior, and the maximum load of the high-strength lattice girders were 1.0 to 1.2 times greater than the H-profiles. By the results of the three-dimensional tunnel cross-section analysis of the supports, the axial force was occurred largely in the lower left and right sides of the tunnel, and showed a similar trend to the field test values. In the results of the measurement of the roof settlement and rod extension, the final displacement of the steel arch rib (H-profile) and high-strength lattice girder section in tunnel was converged to a constant value without significant difference within the first management standard of 23.5 mm. According to the results of underground displacement measurement, the final change amount of the two support sections showed a slight displacement change, but converged to a constant value within the first management standard of 10 mm. By the results of measurement of shotcrete stress and steel arch rib stress, the final change amount of the two support sections showed a slight stress change, but converged to a constant value within the first management standard of 81.1 kg/㎠ and 54.2 tonf.

Reinforcement Effect of Stabilizing Piles in Large-scale Cut Slops (대절토사면에 보강된 억지말뚝의 활동억지효과에 관한 연구)

  • 홍원표;한중근;송영석;신도순
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.06a
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    • pp.65-81
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    • 2003
  • During the last few decades in Korea, the development of hillside or mountain areas has rapidly increased for infrastructure construction such as railroads, highways and housing. Many landslides have occurred during these constructions. Also, the amount and scale of damage caused by landslides have increased every year. In the case of Far East Asia including Korea, the damage of landslides is consequently reported during the wet season. In this paper, the effect of stabilizing piles on slope stability is checked and the behavior of slope soil and piles are observed throughout the year by field measurements in the large-scale cut slopes. In particular a large-scale cut slope situated on the construction site for the express highway in Donghae, Korea. First of all, The behavior of the slope soil was measured by inclinometers during slope modification. Landslides occurred in this area due to the soil cutting for slope modification. The horizontal deformations of slope soil gradually increased and rapidly decreased at depth of sliding surface indicating that the depth of sliding surface below the ground surface can be predicted. On the basis of being able to predict the depth of the sliding surface, stabilizing piles were designed and constructed in this slope. To ensure the stability of the reinforced slope using stabilizing piles, an instrumentation system was installed. The maximum deflection of piles is measured at the pile head and it is noted that the piles deform like deflection on a cantilever beam. The maximum bending stress of piles is measured at the soil layer. The pile above the soil layer is subjected to lateral earth pressure due to driving force of the slope, while pile below soil layer is subjected to subgrade reaction against pile deflection. As a result of research, the effect and applicability of stabilizing piles in large-scale cut slopes could be confirmed sufficiently.

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Effect of Texturized Soy Protein on the Sensory Characteristics and Texture of N[eat Balls (Wanja) (조직콩 단백의 첨가가 쇠고기 완자의 기호 및 Texture에 미치는 영향)

  • 정락원;이효지
    • Korean journal of food and cookery science
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    • v.1 no.1
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    • pp.65-73
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    • 1985
  • In this study, we tried to compare and determine wat the effects will be to the sensory characteristics and textures of a meat balls when the proportion of the textu-rized soy protein (TSP) varies from 0, 10, 20, 30, and 40%. Evaluation was conducted through sensory evaluation and objective evaluation. The results are as follows: 1. As the level of 40% TSP increased the meat ball maintained a better appearance. 2. Color, beef flavor, tenderness, juiciness and acceptability shelved the tendency to decrease as TSP proportion increased. (1) No significant change to the outside color revealed to the level of 20%. How-ever, inside color showed a significant change after the level exceeded 20%. (2) Soy flavor tended to increased and beef flavor tended to decrease as the TSP proportion increased. However up to the level of 30% one could not taste the flavor of soy. (3) Tenderness tended to decrease as the TSP proportion increased however difference was not significant. (4) Juiciness decreased as TSP proportion increased. (5) Acceptability tended to decrease as the TSP proportion increased but to a 40% addition, the level of TSP did not have much effect on the sensory characteristics as long as sufficient seasonings were added. 3. Instron measurement incidated that springiness, cohesiveness and shear force tended to dcrease as the TSP proportion increased but hardness increased and chewi-ness was the highest at 20% TSP level. 4. Color and difference meter indicated that the figure L and b tended to increase and AE decreased as the TSP proportion increased. 5. Cooking retention tended to increase as the TSP proportion increased. From thiss tudy, we can conclude that the level of up to 40% of TSP in making meat ball did not affect the preference.

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Correlation between Balance Ability, Muscle Strength, and Muscle Endurance, in Taekwondo, Soccer, and Gymnastics Athletes (태권도, 축구, 체조 선수들의 균형능력과 근력, 근지구력의 상관분석)

  • Park, Seok-Woo;Ryu, Young;Kim, Kew-Wan
    • Korean Journal of Applied Biomechanics
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    • v.24 no.1
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    • pp.85-93
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    • 2014
  • The purpose of this study was to investigate a relationship among Taekwondo, soccer and gymnastic athletes their balance ability and lower extremity muscle strength, muscle endurance and also whether these variables show differences by sports type. For this purpose, 10 Taekwondo athletes, 10 soccer athletes and 10 gymnastic athletes that is a high school in I area were selected and their balance ability, isokinetic muscle strength and muscle endurance were measured by using force platform (AMTI) and isokinetic measurement (HUMAC NORM). Then the following results were obtained by conducting pearson product-moment correlation analysis and one-way ANOVA. In case of both right and left foot one-leg standing with open-eyes, there was a relation between both knee extension maximal muscle strength of Taekwondo, soccer, gymnastic athletes and balance ability, and in case of right foot one-leg standing with open-eyes, there was a relation between that is right plantar flexion and dorsi flexion maximum muscle strength and muscle endurance of Taekwondo, soccer, gymnastic athletes and their balance ability. Furthermore, in case of left dorsi flexion maximum muscle strength, there were significant differences in order of Taekwondo, gymnastics and soccer, and for isokinetic plantar flexion maximum muscle endurance, both right and left showed significant differences in order of Taekwondo, gymnastic and soccer.

Electrical and optical properties of Indium Zinc Tin Oxide thin films deposited by RF magnetron sputtering (RF magnetron sputtering에 의해 증착된 Indium Zinc Tin Oxide 박막의 전기적, 광학적 특성.)

  • Nam, Tae-Bang;Choi, Byung-Hyun;Ji, Mi-Jung;Seo, Han;Won, Ju-Yeon;Ju, Byeong-Kwon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.96-96
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    • 2009
  • 투명전도막은 FPD의 전자부품에서 전극으로 널리 사용되고 있으며 현재 대부분의 투명전도막으로는 ITO가 사용되고 있다. 하지만, ITO에 사용되는 In은 희유금속으로 지속적인 사용량 증가로 가격의 급등과 더불어 수급 불안정으로 인해 In을 대체하고자 하는 연구가 집중적으로 이루어지고 있다. 그러나 $In_2O_3$를 대체한 ZnO계 등은 비저항이 높아 대체 적용이 가능하지 못하고 있다. 이에 In의 양을 줄이면서 상대적으로 저가이면서 광학적 특성이 우수한 ZnO을 첨가하여 기존의 ITO에 상응하는 전기전도도와 광투과율을 얻을 수 있는 새로운 3성분계 TCO 에 대한 연구가 활발히 이루어지고 있다. 따라서, 본 연구그룹은 $In_2O_3$을 기본 조성으로 하는 $In_2O_3-ZnO-SnO_2$계를 선정하여 IZTO target을 제조 후 RF magnetron sputtering 방법으로 투명전도막을 제작하였다. 본 연구에서는 RF 파워와 동작압력, 동작시간 그리고 열처리온도의 증착 조건에 따른 IZTO 박막의 특성을 평가하였다. 박막의 특성 및 표면 미세구조를 관찰하기 위해 AFM(Atomic Force Microscope)을 이용하였으며, XRD(X-ray diffraction)을 이용하여 결정성을 분석하였고, 4 point-prove, Hall effect measurement와 UV/Visible spectrometer를 통해 전기적, 광학적 특성을 평가하였다.

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Development of an Intelligent Ankle Assistive Robot (지능형 발목 근력 보조 로봇의 개발)

  • Jeong, Woo-Chul;Kim, Chang-Soon;Park, Jin-Yong;Hyun, Jung-Guen;Kim, Jung-Yup
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.6
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    • pp.538-546
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    • 2015
  • This paper describes an intelligent ankle assistive robot which provides assistive power to reduce ankle torque based on an analysis of ankle motion and muscle patterns during walking on level and sloped floors. The developed robot can assist ankle muscle power by driving an electric geared motor at the exact timing through the use of an accelerometer that detects gait phase and period, and a potentiometer to measure floor slope angle. A simple muscle assistive link mechanism is proposed to convert the motor torque into the foot assistive force. In particular, this mechanism doesn't restrain the wearer's ankle joint; hence, there is no danger of injury if the motor malfunctions. During walking, the link mechanism pushes down the top of the foot to assist the ankle torque, and it can also lift the foot by inversely driving the linkage, so this robot is useful for foot drop patients. The developed robot and control algorithm are experimentally verified through walking experiments and EMG (Electromyography) measurements.

Activity and Safety Recognition using Smart Work Shoes for Construction Worksite

  • Wang, Changwon;Kim, Young;Lee, Seung Hyun;Sung, Nak-Jun;Min, Se Dong;Choi, Min-Hyung
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.2
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    • pp.654-670
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    • 2020
  • Workers at construction sites are easily exposed to many dangers and accidents involving falls, tripping, and missteps on stairs. However, researches on construction site monitoring system to prevent work-related injuries are still insufficient. The purpose of this study was to develop a wearable textile pressure insole sensor and examine its effectiveness in managing the real-time safety of construction workers. The sensor was designed based on the principles of parallel capacitance measurement using conductive textile and the monitoring system was developed by C# language. Three separate experiments were carried out for performance evaluation of the proposed sensor: (1) varying the distance between two capacitance plates to examine changes in capacitance charges, (2) repeatedly applying 1 N of pressure for 5,000 times to evaluate consistency, and (3) gradually increasing force by 1 N (from 1 N to 46 N) to test the linearity of the sensor value. Five subjects participated in our pilot test, which examined whether ascending and descending the stairs can be distinguished by our sensor and by weka assessment tool using k-NN algorithm. The 10-fold cross-validation method was used for analysis and the results of accuracy in identifying stair ascending and descending were 87.2% and 90.9%, respectively. By applying our sensor, the type of activity, weight-shifting patterns for balance control, and plantar pressure distribution for postural changes of the construction workers can be detected. The results of this study can be the basis for future sensor-based monitoring device development studies and fall prediction researches for construction workers.