• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.55-63
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• 2008

Fine blanking is a process of press shearing which makes it possible to produce the thick sheet metal of the finished surface and the close dimensional accuracy over the whole material thickness in the single blanking operation. In this paper, a plate holder of automotive seat recliner is manufactured by FCF(Flow Control Forming) method using the conventional mechanical press instead of the fine blanking press. Main processes for manufacturing of the plate holder by FCF method are embossing, half blanking and trimming processes. Optimal clearance, stripper force and counter force to increase the dimensional accuracy of the plate holder have been investigated by FE-analysis. As a result of FE-analysis, the clearance for both embossing and half blanking processes was -2%t and the forces of stripper and counter were 25ton and 15ton, respectively. After manufacturing the plate holder by FCF method, the measured dimensional characteristics have been compared with the required specifications as the final product. Although the dimensional accuracy of the plate holder manufactured by FCF method was a little inferior to that by fine blanking process, it was satisfactory in a general sense.

• Nuclear Engineering and Technology
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• v.4 no.1
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• pp.39-45
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• 1972

In neutron shielding, the scattering effect is equally important as the attenuations in shielding materials. In the present study, the scattered dose equivalent was measured using a Rem counter for water, paraffin, borated paraffin, ordinary and heavy concrete, lead, iron, and tissue equivalent material in three different angles: 45$^{\circ}$, 90$^{\circ}$, and 135$^{\circ}$, respectively. The measurements were performed for the neutron, having the energies of 0.5, 1, 2, 5, and 18 MeV, which are produced from the Van do Graaff accelerator. The scattered dose equivalent ratios were increased with increasing the thickness of scattering materials and saturated at a certain thickness although they were different from one to other materials under study. The ratios were large for lead and iron while they were small for the hydrogen containing materials such as water and paraffin etc.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.2 s.257
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• pp.253-259
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• 2007

A new material tester has been developed to measure mechanical properties of thin film specimens at high temperature. It is useful for observing oxide film growth or local deformation on the surface, and for measuring creep strength. Main characteristics of the tester is as follows; First, high temperature is achieved by Joule heating generated by electricity passing through the specimen, which does not need to enclose the specimen by a furnace or a heating chamber. The exposed specimen enables one to observe the surface during the test. Because the overall size of the test rig is compact, the whole test rig can be placed in a chamber for environmental controlled tests. The loading device is from a level scales. Not only static load with fixed counter weight, but also variable load by moving counter weight controlled remotely can be applied for an ordinary creep test and creep-fatigue test, respectively. The detail of the construction, operation principle, and the specification are described. And also, an example of test result obtained using the creep tester is presented.

• Journal of radiological science and technology
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• v.44 no.4
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• pp.381-387
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• 2021

In this study, for the measurement of 3H(tritium) radioactivity concentration, a study was conducted on whether the type of cocktail and the material of the vial had an effect on the measurement before liquid scintillation counter measurement on HTO-type samples that had undergone physical and chemical pretreatment. As a result of the study, the efficiency according to the type of cocktail was higher in Ultima Gold LLT than Ultima Flo-AP cocktail with polyethylene (1.49%), glass (5.10%), and teflon (6.58%), respectively. Regarding the effect according to the type of vial, the efficiency and SQP(E) of both Ultima Gold LLT and Ultima Flo-AP showed the highest values in the order of teflon, polyethylene, and glass.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1048-1052
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• 2005

In Korean cases, the occupation of building construction is below 10% of the total industry workers but from a accident rate point of view, it is a risk serious industry and it's hazard is very considerable which accident rate is up to 30% of the total industry workers. The reason of high accident rate of the building construction is its own characteristic, hazard of the work in which is implicated and the shortage of safety counter plan and information, so it is most required to the building construction that educating, training, short and long period approaching to prevent the hazard. The safety information of building construction which is related to safety accident is divided into human and material such as hazard, work situation, cause and counter plan. The existing hazard cases imply all of the information about the work type and work progress of the building construction, so if the research of the every fact is well accomplished, we can obtain the useful information and prevent the hazard of building construction. From this point of view, the emphasis of this study is based on analyzing the cause of hazard first, suggesting the safety information each part of work type and work progress second, and finally making the all existing hazard cases to the Data Base and developing the safety information system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.2
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• pp.85-91
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• 2015

A gasoline engine automobile uses high voltage generation of the ignition coil, igniting and burning mixed fuel in the combustion chamber, which drives the engine. When the electronic control unit intermits a current supplied to the power transistor, counter electromotive force with a low voltage is generated by self induction action in the ignition primary coil and a high voltage is induced by mutual induction action with the primary ignition coil in the second ignition coil. The high voltage is supplied to the ignition plug in the combustion chamber, causing a spark, igniting the compressed mixed fuel. If a very small defect occurs inside the insulating material when a voltage is applied in said ignition coil, the performance of the insulation material will get worse and breakdown by a partial discharge of corona discharge. Thus, in this experiment, we are to contribute to improve the performance and ensure the reliability of the ignition coil by investigating partial discharge characteristics according to the change of voltage and temperature when a voltage is applied to the specimen of the epoxy molding ignition coil.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.55-63
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• 2001

Friction and wear properties of brake friction materials containing different metal fibers (Al, Cu or Steel fibers) were investigated using a pad-on-disk type friction tester. Two different materials(gray iron and Al-MMC)) were used for disks rubbing against the friction materials. Results from ambient temperature tests revealed that the friction material containing Cu fibers sliding against cast iron disk showed a distinct negative ${\mu}$-ν (friction coefficient vs. sliding velocity) relation implying possible stick-slip generation at low speed. The negative ${\mu}$-ν relation was not observed when the Cu-containing friction materials were rubbed against the. Al-MMC counter surface. As applied loads increased, friction materials showed higher friction coefficients comparatively. Friction materials slid against cast iron disks exhibited higher friction coefficients than Al-MMC disks during high temperature tests. On the other hand, high temperature test results suggested that copper fibers in the friction material improved fade resistance and the steel fibers were not compatible with Al-MMC disks showing severe material transfer and erratic friction behavior during sliding at elevated temperatures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05b
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• pp.43-46
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• 2002

We have investgated the photoisomerization using light irradiation 8A5H-phospholipid( L-$\alpha$-dimyristoylphosphatidylcholine[DMPC], L-$\alpha$-dilauroylphosphatidylcholine[DLPC]mixture LB film accumulated by monolayer on an ITO. We determined electrochemical measurement by using cyclic voltammetry with a three-electrode system, An Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode measured in $NaClO_{4}$ solution at a variable concentration and variable number layers LB film. The scan rate was 100mV/s.

• Fire Science and Engineering
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• v.12 no.1
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• pp.27-33
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• 1998

Arson is one of the serious crime. It shows high increasing rate compared with the past, and the causes of arson are getting diversified and specialized in this modern society. In this thesis, the actual state and tendency of arson during latest 5 years have been analyzed on the basis of 'crime analysis' which is material of the National Police Agency. Based on the above analyzed material, measures for arson in foreign countries are examined and necessary matters to counter arson in Korea are inferred.

• Korean Institute of Interior Design Journal
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• no.34
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• pp.78-85
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• 2002

This study aims at alalyzing the circulation process, merchandising system of Mosi(Korean traditional garment material), and accessing the way of interior design of Mosi market. There are three kinds of garment material of Mosi such as Pilmosi, Gootmosi, Taemosi classified by manufacturing process. At Mosi market, these three materials are sold in due sequence. Mosi market needs three space zones such as Mosi market space, inspecting space of Mosi and resting place, and these three spaces have strong interrelationship, so designer should plan not to disterb the moving flow. In the Mosi market space there should be divided by three zones such as Pilmosi marketing place, Gootmosi marketing place, and Taemosi marketing place in due sequence. The furniture of Mosi market place divided two kinds such as furniture for Pilmosi and that of Gootmosi or Taemosi. The proper form of furniture for Pilmosi is circular arc bar counter and that for Gootmosi or Taemosi is low rectangular table.