• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.626-631
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• 2004

In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a re-adhesion control algorithm which uses the maximum adhesive effort by instantaneous estimation of adhesion force using load torque disturbance observer. Based on this estimated adhesive effort, the re-adhesion control is performed to obtain the maximum transfer of the tractive effort.

• 한국철도학회논문집
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• 제6권4호
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• pp.257-264
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• 2003

In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a re-adhesion control algorithm which uses the maximum adhesive effort by instantaneous estimation of adhesion force using load torque disturbance observer. Based on this estimated adhesive effort, the re-adhesion control is performed to obtain the maximum transfer of the tractive effort.

• 한국식품영양학회지
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• 제9권4호
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• pp.424-429
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• 1996

전분의 첨가가 냉동면의 조직감과 관능적 특성에 미치는 영향을 밝히기 위하여 감자초산변성전분, 옥수수초산변성전분, 찰옥수수전분, 옥수수전분, 감자전분, 밀전분 등 6종의 전분을 함량별로 첨가하여 복합분을 제조하였다. 이들의 아밀로그래프, 제면시의 조리시험, 냉동, 해동후 면의 최대절단강도를 측정하고 관능평가하였다. 감자초산변성전분과 감자전분을 첨가한 복합분의 호화개시온도는 대조구인 소맥분 100%보다 다소 낮아졌다. 최고점수는 초산변성전분류, 찰옥수수, 감자전분을 첨가한 경우 다소 높아졌다. 조리시의 체적과 중량은 다소 증가하고 고형분 용출량은 변성전분과 찰옥수수전분을 참가한 경우 다소 감소하였다. 냉동, 해동 조리 후 면의 최대절단강도는 감자초산변성전분 15%와 20%, 옥수수초산변성전분 15%를 첨가한 경우에 대조구보다 커졌다. 감자전분을 제외한 나머지 5종의 전분을 첨가시에 냉동면의 조직감과 색깔이 다소 향상되는 것으로 나타났다. 그 중에서 감자초산변성전분의 효과가 가장 높았다.

• Journal of Advanced Research in Ocean Engineering
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• 제4권3호
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• pp.115-123
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• 2018

This study was carried using the new approach method to design appropriately the Loading Arm length and the alarm setting according to ship movements on Loading and Unloading marine Berth. The quasi-static mooring analysis was performed to estimate 110,000DWT ship's movements based on environmental conditions such as wind, current and wave. The mooring motion of the ship is very important to determine the loading arm scope, and in this case, the operation condition is performed on the ship without considering the damaged condition of the mooring line because the ship movement in case of damage is larger than intact, and all operations are stopped, the loading arm being released due to control system. From the result of mooring analysis, motion displacements, velocities and accelerations were simulated. They were used to simulate the maximum drifting speeds and distances. The maximum drifting speeds were checked to be satisfied within drifting speed limits. The total maximum drifting distances were simulated with alarm steps of the new approach method. Finally, the loading arm envelopes using the total maximum drifting distances were completed. Therefore, it was confirmed that the new approach method for loading arm envelopes and alarm settings was appropriate from the above results. In the future, it will be necessary to perform the further advanced dynamic mooring analysis instead of the quasi-static mooring analysis and to use the precise computer program analysis for various environments and ship movement conditions.

• 센서학회지
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• 제27권4호
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• pp.259-263
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• 2018

A radial artery pulse wave is measured while pressing an artery with constant force. However, pulse waveform measurements vary depending on pressing force and direction. Accurate pulse waveform measurements are important for analysis. Thus, it is necessary to define the measurement range of the permissible force and direction from which a correct pulse waveform is derived. In this study, pulse waves were generated by a pulse wave generator for accurate control. The pulse waves generated for different angles and pressing forces were analyzed. The augmentation index (AIx), which is the most commonly used index for evaluating vascular stiffness, was analyzed. The AIx was measured within ${\pm}6^{\circ}$ of the vessel direction and within ${\pm}8^{\circ}$ perpendicular to the vessel direction with a force that was 25% or more of the pressing force at which the maximum pressure wave was generated. We identified the applicable pressing force and angle range by analyzing the effect of pressing angle on the pulse wave. The AIx analysis performed using the pulse wave measurement device is reliable and reproducible.

• 한국운동역학회지
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• 제21권1호
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• pp.9-16
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• 2011

The purpose of this study is to analyze the effects of both various shoe types and bare feet on ground reaction force while walking. Ten first-year female university students were selected. A force platform(Kistler, Germany) was used to measure ground reaction force. Six types of shoe were tested: flip flops, canvas shoes, running shoes, elevated forefoot walking shoes, elevated midfoot walking shoes, and five-toed shoes. The control group was barefooted. Only vertical passive/active ground reaction force variables were analyzed. The statistical analysis was carried out using the SAS 9.1.2 package, specifically ANOVA, and Tukey for the post hoc. The five-toed shoe had the highest maximum passive force value; while the running shoe had the lowest. The first active loading rate for running shoes was the highest; meanwhile, bare feet, the five-toed shoe, and the elevated fore foot walking shoe was the lowest. Although barefoot movement or movement in five toed shoes increases impact, it also allows for full movement of the foot. This in turn allows the foot arch to work properly, fully flexing along three arches(transverse, lateral, medial), facilitating braking force and initiating forward movement as the tendons, ligaments, and muscles of the arch flex back into shape. In contrast movement in padded shoes have a tendency to pound their feet into the ground. This pounding action can result in greater foot instability, which would account for the higher loading rates for the first active peak for padded shoes.

• Geomechanics and Engineering
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• 제29권3호
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• pp.229-236
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• 2022

In this study, a model experiment and field experiment was conducted to introduce the optimal tensile force when constructing a non-open cut tunnel according to the ground conditions of sandy soil. CMR (Concrete Modular Roof) method is economical because of the high precision and excellent durability, and corrosion resistance, and the inserted parts can be used as the main structure of a tunnel. In addition the CMR method has a stable advantage in interconnection because the concrete beam is press-fitted compared to the NTR (New Tubular Roof) method, and the need for quality control can be minimized. The ground conditions were corrected by adjusting the relative density of sandy soil during the construction of non-open cut tunnels, and after introducing various tensile forces, the surface settlement according to excavation was measured, and the optimal tensile force was derived. As a result of the experiment, the amount of settlement according to the relative density was found to be minor. Furthermore, analysis of each tensile force based on loose ground conditions resulted in an average decrease of approximately 22% in maximum settlement when the force was increased by 0.8 kN per segment. Considering these results, it is indicated that more than 2.0 kN tensile force per segment is recommended for settlement of the upper ground.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.302-307
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• 2005

Recently, lots of parallel mechanisms for spatial 3-DOF and 6-DOF were investigated. However, research on 4-DOF and 5-DOF parallel mechanisms has been very few. In this paper, we propose a 4-DOF parallel mechanism that consists of 3-rotational and 1-translational motions. The kinematic characteristics of this mechanism are analyzed in terms of an isotropic index and maximum force transmission ratio, and its kinematic optimization is being conducted to ensure enhanced kinematic performances

• Smart Structures and Systems
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• 제18권5호
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• pp.1005-1028
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• 2016

Two novel semi-active control methods for a seismically excited nonlinear benchmark building equipped with magnetorheological dampers are presented and evaluated in this paper. While a primary controller is designed to estimate the optimal control force of a magnetorheological (MR) damper, the required voltage input for the damper to produce such desired control force is achieved using two different methods. The first technique uses an optimal compact Takagi-Sugeno-Kang (TSK) fuzzy inverse model of MR damper to predict the required voltage to actuate the MR dampers (TSKFInv). The other voltage regulator introduced here works based on the maximum and minimum capacities of MR damper at each time-step (MaxMin). Both semi-active algorithms developed here, use acceleration feedback only. The results demonstrate that both TSKFInv and MaxMin algorithms are quite effective in seismic response reduction for wide range of motions from moderate to severe seismic events, compared with the passive systems and performs better than original and Modified clipped optimal controller systems, known as COC and MCOC.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.951-955
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• 2004

Piezoelectric(PZT) actuator can substitute for solenoid which is used in fluid control field because it has faster response times and no possibility of explosion. Besides, it is available in a high temperature and it has low energy consumption. In this study, pneumatic micro valve, bimorph type PZT actuator using the softner type PZT, carbon plate as a shim and its controller circuit were suggested and investigated. Performance tests and characteristics analysis, such as displacement, force, hysteresis and frequency properties, were carried out. The displacement of the actuator measured at the end point was 63 ${\mu}m$., force of the actuator was 0.052 N and maximum operating frequency was 15Hz. Also, characteristics of the micro valve with PZT actuator were evaluated in a testing system. The results show that the suggested PZT actuator is suitable for micro valve.