• Korean Management Science Review
• /
• v.10 no.2
• /
• pp.121-143
• /
• 1993

Traditional Manufacturing method is push system by plan made in advance and Japanese manufacturing method represented by JUST-IN-TIME is pull system which respond's to the demand flexibly. Both have their pros and cons. In general, it is well understood that push system is faster than pull system in the sense of manufacturing speed. However, pull system such as JIT excelles dramatically in the sense of work in process. Therefore, this paper is trying to put together to get alternative which has the advantage of both system. The objective of the paper is to enhance the effect of built-in manufacturing system without paying extra cost by way of introducing the alternative of the pull-push manufacturing strategic operational method.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.15 no.1
• /
• pp.36-44
• /
• 2005

A push pull hood system is frequently applied to control contaminants evaporated from an open surface tank in recent years. Efficiency of push pull hood system is affected by various parameters, such as cross draft, vessel shapes, size of tanks surface, liquid temperature, and so on. Among these, velocity of cross draft might be one of the most influencing factor for determining the ventilation efficiency. To take account of the effect of cross draft velocities over 0.38m/s, a flow adjustment of ${\pm}$20% should be considered into the push and +20% into the pull flow system Although there are many studies about the efficiency evaluation of push pull hood system based on CFDs(Computational Fluid Dynamics) and experiments, there have been no reports regarding the influence of velocities and direction of cross-draft on push-pull hood efficiency. This study was conducted to investigate the influence of cross draft direction and velocities on the capture efficiency of the push-pull ventilation system. Smoke visualization method was used along with mock-up of push-pull hood systems to verify the ventilation efficiency by experiments. When the cross-draft blew from the same origins of the push flows, the efficiency of the system was in it's high value, but it was decreased significantly when the cross-draft came from the opposite side of push flows Moreover, the efficiency of the system dramatically decreased when the cross-draft of open surface tank was faster than 0.4m/s.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.478-480
• /
• 2008

On this paper, digitally controlled push-pull dc-dc converter and dc-ac inverter for induction motor control are presented, which is used one DSP(digital signal processor). This system has 12V battery input for the push-pull converter, and the push-pull converter generates 300V output for induction motor inverter input. In order to compensate the push-pull converter, the transfer function of push-pull converter is derived and digital PI compensator is adapted. Through bode diagram, stability of digital controlled push-pull converter is analyzed. To verify the proposed system, digital simulation of the induction motor drive using digital push-pull converter are performed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.05a
• /
• pp.556-559
• /
• 2003

This paper presents a study on pull cord switch system which is employed in various industry for emergency stop of the equipments. In this paper, a new method for operation position detection of pull cord switch is suggested which is based on sensing operation position by detecting input resistance variation due to switching operation of pull cord switches with respective ohmic resisters. Moreover, this paper proposes a resistor circuit structure in order to improve recognition rates. Finally, this paper treats a system where such operating switches can be read by PLC.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.03a
• /
• pp.545-552
• /
• 2008

To insure the quality and safety of ground anchors, pull-out test of anchor has to be done. In the individually controlled pull-out test system, pull-out device is used to introduce the same pull-out force to individual tendon that has a different length and a deflection. That is, that device has a separate pull-out oil jack to each tendon, thus the pull-out length of each jack is not the same, but that device introduces each tendon to the same pull-out force. In this study, the in-situ pull-out tests for the compression anchors were performed and its test results were analysed and compared to the results of center hole pull-out tests. In the case of pulling out each tendon using the individually controlled pull-out test device, the pull-out forces were distributed to a individual tendon. That device is excellent one that can solve the cause of unequal pull-out forces of each tendon appearing in the manufacture process and construction of anchors, and unequal pull-out forces due to the deferent length.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.137-144
• /
• 2005

Recently a pressurized grouting soil nail is demanded due to problems beyond of economical and engineering purpose. In this study, a newly modified soil nailing technology named as the PGSN (Pressurized Grouting Soil Nailing) system is respected to reduced displacements of nails and increase of global slope stability. And effects of various factors related to the design of the PGSN system, such as the length of the soil nail, injected pressure and W/C ratio of cement grout in the pressurized grouting soil nail are examined throughout a series of the displacement-controlled field pull-out tests. Displacement-controlled field pull-out tests are performed in the present study and the volume of grouting are also evaluated based on the measurements. In addition, both short-term and long-term characteristics of pull-out deformations of the newly proposed PGSN system are analyzed and compared with those of the general soil nailing system by carrying out the stress-controlled field pull-out tests. From the pull-out characteristics of pressurized grouting soil nails, it is found that the effect of the length of the soil nail, injected pressure and W/C ratio of cement grout are important parameters.

• Journal of Welding and Joining
• /
• v.31 no.3
• /
• pp.39-43
• /
• 2013

It is difficult to feed welding wire stably, when the distance between welding wire feeder and welding torch is far enough. In order to solve this problem, arranging a extension wire feeder between them could be one of useful methods. However, the welding wire could be twisted up in the extension cable between extension and terminal wire feeders in the case that RPM of extension wire feeding motor is higher than that of terminal motor. In this study, feeding problem of normal push-pull wire feeding system occurred at low welding current range less than 250A. In order to solve the problem, two new wire feeding systems of push-pull type were introduced. Welding wire feeding tests were preformed in the range of 150A to 400A with the developed push-pull feeding system. In addition, weldability test was performed at the welding current of 200A, 300A, and 400A. The welding wire twisting problem that was observed in the normal feeding system did not occur in the new push-pull wire feeding system.

• Proceedings of the SAREK Conference
• /
• 2007.11a
• /
• pp.594-599
• /
• 2007

This study represents numerical analysis on the fluid flow and concentration characteristics by scattering fume at push-pull ventilation system. And the principal point is making optimum on improve an existing ventilation system. This phenomenon simulated about local ventilation system by using commercial CFD tool and base on these fact has find improvements. Advanced model shows most low different pressure and velocity which are suction capability at inlet surface of pull hood has most uniformity. When compared with existing model, Improved model has more good ventilation performance.

• Journal of Biosystems Engineering
• /
• v.14 no.2
• /
• pp.67-79
• /
• 1989

This study was conducted to investigate the applicability of true model theory for pull prediction in a powered lugged wheel-soil system and to examine the possibility of using principles of similitude in investigating the dimensions of soil parameters pertinent to a powered lugged wheel-soil system concerning the pull prediction. The following conclusions were derived from the study; 1) The pull of prototype wheels proved to be predicted by those of the model wheels for the range of the dynamic weight tested. The pull curves of models and prototype were respectively very similar in the shape. From this basic knowledge, it was enabled to apply the similitude theory to the performance prediction of the true model. 2) A conditional equation which can be used for the prediction of pull of prototype by model test was derived as follows. $n_f=n_1^{-b}$ where $n_f$ : force scale = $w/w_m$ $n_1$ : length scale = ${\ell}/{\ell}_m$ b : exponent on the length dimension of the soil property ${\alpha}$ The range of the numerical value of b, which was determined by the least square method, was found to be -2.0~-2.6. 3) Considering a relatively wide variation of b values in the pull prediction, b is considered to be a function of many variales. Thus it was concluded that there are several soil properties which are pertinent to the powered lugged-wheel-soil system concerning the pull prediction, and these soil properties may have the different effects on the pull of model and protytype wheels, to give the different dimension on the soil parameters.

• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.2
• /
• pp.152-159
• /
• 2001

This paper presents a development of the recoil rod pull force measurement system suing the load cell with a sleeve normally available in the recoil system test. The commercial load cell cannot be used in the test of recoil system floating the breach contact point freely in the air. The load cell is designed and manufactured to meet the recoil system test condition. Theoretical analysis and experimental results show that the accuracy of the developed measurement system is within $\pm$0.5%. We notice that the measurement technique proposed in this paper is accurate and useful in the recoil rod pull force measurement of the recoil system.