• Title/Summary/Keyword: Continuous rotation

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Novel Process of Precision Nickel Mesh Fabrication for EMI Shielding Using Continuous Electroforming Technique (연속전주공정을 이용한 전자파 차폐용 정밀니켈메쉬 제조 신공정)

  • Lee Joo-Yul;Kim Man;Kwon Sik-Chol;Hue Nguyen Viet;Kim In-gon
    • Journal of the Korean institute of surface engineering
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    • v.38 no.6
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    • pp.212-215
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    • 2005
  • Novel continuous electroforming process equipped with a rotating patterned mandrel, soluble/insoluble anode and multiple stage of rolling wheels was proposed to produce precision nickel mesh, which is known as a very efficient electromagnetic interference (EMI) shielding material. Continuously electroformed nickel deposits showed a tendency to form small-sized particles as the plating solution temperature increased and mandrel rotation speeded up and the applied current density decreased. Along the honeycomb patterns of mandrel, nickel was accurately electrodeposited on the surface of rotating mandrel, but quite different visual/structural characteristics were measured on both sides.

Continuous Degradation of Formaldehyde by Peudomonas putida H-5 Using Rotation Disc Contactor (회전원판반응조에 의한 Peudomonas putida H-5의 포름알데히드의 연속적 분해)

  • 류병호;임복규
    • KSBB Journal
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    • v.8 no.1
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    • pp.42-48
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    • 1993
  • Continuous degradation of formaldehyde by using a rotating disc contactor was investigated in this study. Peudomonas putida H-5K was selected as a mutant using N-methyl N'-nitro N-nitrosoguandine (250$\mu\textrm{g}$/$m\ell$), which showed 1.5 times higher ability of formaldehyde degradation than that of the parent strain. Enzyme activity for formaldehyde degradation released form Peudomonas putida H-5K showed the highest level of 6.2mo1/min/mg protein in the 2% glucose mineral medium containing 0.02% formaldehyde. Degradation of formaldehyde from the first stage in rotating disc contactor was 95% and 5% from the 4th stage when the reactor was fed with 0.02% or 0.04% formaldehyde solution at a rate of 20$m\ell$ per hour. Continuous degradation of formaldehyde using rotating disc contactor was above 95%o in the medium containing 0.04% formalchyde, at the medium feed ratc of 20$m\ell$ per hour.

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Analytical Study on the Flexural Moment Redistribution of Continuous Reinforced Concrete Beams (철근콘크리트 연속보의 휨모멘트 재분배에 관한 해석적 연구)

  • Cheon, Ju-Hyun;Seong, Dae-Jeong;Lee, Sang-Cheol;Shin, Hyun-Mock
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.385-388
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    • 2006
  • The purpose of this study is to offer an appropriate method of the degree of the flexural moment redistribution for continuous reinforced concrete beams. Twenty-four two-span continuous beams were selected to determine the manner and degree of moment redistribution. The concept of ductility is linked to the moment redistribution capacity and, consequently, the safety of the structure. Knowledge of the plastic rotation capacity of plastic regions of the structure is important for a plastic analysis or a linear analysis with moment redistribution. A nonlinear finite element analysis program named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology) was used to evaluate the ultimate strength and degree of moment redistribution. The nonlinear material model for the reinforced concrete is composed of models for characterizing the behavior of the concrete, in addition to a model for characterizing the reinforcing bars.

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Growth and Yield Characteristics of Foxtail Millet, Proso Millet, Sorghum and Rice in Paddy-Upland Rotation (답전윤환에서의 조, 수수, 기장 및 벼의 생육 및 수량)

  • Yoon, Seong-Tak;Kim, Young-Jung;Jeong, In-Ho;Han, Tae-Kyu;Yu, Je-Bin;Ye, Min-Hee;Cho, Young-Son;Kang, Hang-Won
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.60 no.3
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    • pp.300-307
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    • 2015
  • In order to develop optimum paddy-upland rotation system, we evaluated the 1st and the 2nd upland growth and yield characteristics of foxtail millet, proso millet, sorghum rotated from paddy field and rice rotated from upland in paddy-upland rotation. Average number of ears per hill was 3.3 in the 2nd upland cultivation. The value was greater by 1 ear as compared to 1st upland cultivation (2.2 ears per hill). In average yield per 10a, the 2nd upland cultivation showed 220.3 kg, 23% increased yield compared to the 1st upland cultivation (179 kg per 10a). In average number of ears per hill, the 2nd upland cultivation showed 8.3 ears, increased 4 ears compared to the 1st upland cultivation (4.2 ears per hill). In average yield per 10a, the 2nd upland cultivation showed 152.8 kg, 16.8% increased yield compared to the 1st upland cultivation (130.8 kg per 10a). In average days from seeding to heading of 5 sorghum varieties, there were no significant difference between the 1st (68.6 days) and the 2nd (67.4 days) upland cultivation rotated from paddy field. In the average number of grains per ears, the 2nd upland cultivation showed 2,931.6 grains per ear, 12% increased compared to the 1st upland cultivation (2,619.6 grains per ears). Average yield per 10a of sorghum in the 2nd upland cultivation showed 242.3 kg, 4.6% increased compared to the 1st upland cultivation (231.7 kg per 10a). In growth and yield characteristics of rice in paddy-upland rotation, culm length in paddy-upland-paddy plot showed 82.9 cm, 7.3 cm longer compared to the continuous rice paddy field (75.6 cm). Ear length was also 1 cm longer than that of the continuous rice paddy field. In average number of ears per hill, paddy-upland-paddy plot showed 25.0 ears, 4.3 ears more than that of the continuous rice paddy field (20.7 ears per hill). In average yield of rice per 10a, the paddy-upland-paddy rotation plot showed 526.8 kg, 9.8% higher yield compared to the continuous rice paddy field (479.9 kg per 10a).

Effects of Prolonged Running-Induced Fatigue on the Periodicity of Shank-Foot Segment Coupling and Free Torque

  • Ryu, Ji-Seon
    • Korean Journal of Applied Biomechanics
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    • v.26 no.3
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    • pp.257-264
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    • 2016
  • Objective: The purpose of this study was to determine the periodicity of shank-foot segment coupling and free torque before and after fatigue induced by prolonged running. Method: Fifteen young healthy male participants with a rear-foot strike ran on instrumented dual-belt treadmills at 70% of their maximum oxygen uptake for 65 min. Kinematic and ground reaction force data were collected for 20 continuous strides at 5 and 65 min (considered the fatigued condition). The approximate entropy tool was applied to assess the periodicity of the shank internal-external rotation, foot inversion-eversion, shank-foot segment coupling, and free torque for the two running conditions. Results: The periodicity of all studied parameters, except foot inversion-eversion, decreased after 65 min of running (fatigued condition) for 80% of the participants in this study. Furthermore, 60% of the participants showed similarities in the change of periodicity pattern in shank internal-external rotation, coupling, and free torque. Conclusion: The findings indicated that the foot inversion-eversion motion may pose a higher risk of injury than the shank internal-external rotation, coupling, and free torque in the fatigued condition during prolonged running.

A study on the development of CW(Continuous-Wave) Doppler system for measuring bi-directional blood flow information. (혈류 방향을 구별하는 연속 초음파 도플러 장치에 관한 연구)

  • Kang, Chung-Sin;Kim, Young-Kil
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1239-1242
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    • 1987
  • With the convention CW Doppler velocity meter, bi-directional velocities cannot be separated. The new CW Doppler system usee quadrature detection and phase rotation to Produce simultaneous independent audio and velocity signals for forward and reverse blood flow direction, is fabricated. Specially, this system shows that phase rotation method for flow direction separation provides easy and satisfactory feature. From in vivo blood flow measurement, can easily differentiate typical artery flow from vein flow. and measure both velocity characteristics qualitatively.

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A Finite Element Heat Transfer Analysis with Coupling of Roll and Molten Metal in Direct Rolling Process (직접압연공정에 있어서 롤과 용탕을 연계한 유한요소 열전도해석)

  • 김영도;강충길
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.4
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    • pp.946-957
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    • 1994
  • In the steel industries, direct rolling process for production of strip from molten metal has been investigated to simplify processes, to minimize energy consumption, and to improve quality of the strip. In this study, two kinds of practicable scale cooling rollers are proposed. And heat transfer analysis of pool region and cooling roller considering flow of molten metal and roll rotation respectively using the finite element method are performed to obtain the proper initial condition and to observe cooling characteristics of cooling roller. From the results, variations of solidification final points and temperature distribution in roller are observed quantitatively according to roll rotation.

Study of Marker Detection Performance on Deep Learning via Distortion and Rotation Augmentation of Training Data on Underwater Sonar Image (수중 소나 영상 학습 데이터의 왜곡 및 회전 Augmentation을 통한 딥러닝 기반의 마커 검출 성능에 관한 연구)

  • Lee, Eon-Ho;Lee, Yeongjun;Choi, Jinwoo;Lee, Sejin
    • The Journal of Korea Robotics Society
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    • v.14 no.1
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    • pp.14-21
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    • 2019
  • In the ground environment, mobile robot research uses sensors such as GPS and optical cameras to localize surrounding landmarks and to estimate the position of the robot. However, an underwater environment restricts the use of sensors such as optical cameras and GPS. Also, unlike the ground environment, it is difficult to make a continuous observation of landmarks for location estimation. So, in underwater research, artificial markers are installed to generate a strong and lasting landmark. When artificial markers are acquired with an underwater sonar sensor, different types of noise are caused in the underwater sonar image. This noise is one of the factors that reduces object detection performance. This paper aims to improve object detection performance through distortion and rotation augmentation of training data. Object detection is detected using a Faster R-CNN.

A Study on the Contour Design of the Hinge Mechanism for a Mobile Phone Driven by Continuous Torques (연속적인 회전력으로 작동하는 휴대폰 힌지기구의 윤곽 설계에 관한 연구)

  • Park, Jong-keun;Lee, Soo Jun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.9 no.3
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    • pp.8-18
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    • 2010
  • A total stroke of an opening or closing motion of a hinge mechanism for a folder-type mobile phone is composed of two portions. In the first portion, human fingers act a torque to open or close the folder. In this portion, the rotating folder compresses the coil spring installed in the hinge mechanism. In the last portion, this compressed coil spring generates a torque to rotate the folder. In this study, we have developed an algorithm to design a hinge mechanism to be operated by an arbitrary continuous torque in the first portion of the total stroke. Consequently, we can design hinge mechanisms that satisfy various demands of consumers. A pair of contours installed in the mechanism plays an important role. It transforms the folder's rotational motion into translation to compress the coil spring in the first portion; on the other hand, it transforms translational motion into the folder's rotation in the last portion. Using this algorithm we have designed the pair of the contour curves operated by an arbitrary continuous torque.

Vibration Analysis of Partially Fluid-filled Continuous Cylindrical Shells with Intermediate Supports (유체가 부분적으로 채워진 내부지지 연속 원통셸의 진동해석)

  • 김영완
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.3
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    • pp.244-252
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    • 2004
  • The theoretical method is developed to investigate the vibration characteristics for the partially fluid-filled continuous cylindrical shells with the intermediate supports. The intermediate supports are simulated by two types of artificial springs : the translational spring for the translation for each direction and the rotational spring for a rotation. The springs are continuously distributed along the circumferential direction. By allowing the spring stiffness to become very high compared to the stiffness of the structure, the rigid intermediate supports are approximated. In the theoretical procedure, the Love's thin shell theory is adopted to formulate the theoretical model. The frequency equation of the continuous cylindrical shell is derived by the Rayleigh-Ritz approach based on the energy method. Comparison and convergence studies are carried out to verify and establish the appropriate number of series term and the artificial spring stiffness to produce results with an acceptable order of accuracy. The effect of intermediate supports, their positions and fluid level on the natural frequencies and mode shapes are studied.