• Korean Chemical Engineering Research
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• v.44 no.3
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• pp.265-269
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• 2006

Considerable attention has been given to supply chains and their management in order to increase competitiveness in current ever-increasing business environments. The attention is due to the common belief that SCM contributes to reducing the redundancy between its supply chain entities and increasing profits correspondingly. However implementing SCM in actual industries involves a large number of difficulties unexpected before. In this paper, experiences in implementing SCM in a semiconductor manufacturing enterprise are discussed with some remarks on how process systems engineering can contribute to establishing SCM. It is hoped that the lessons of the specific enterprise can be of good help to others as well.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.73-84
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• 2015

Electricity generation using fossil fuels has caused environmental pollution. To solve this problem, research on new renewable energy sources (solar, wind power, geothermal heat, etc.) to replace fossil fuels is ongoing. These devices are able to generate power consistently. However, they have many weaknesses, such as high installation costs and limits to possible setup environments. Therefore, an active study on piezoelectric harvesting technology that is able to surmount the limitations of existing energy technologies is underway. Piezoelectric harvesting technology uses the piezoelectric effect, which occurs in crystals that generate voltage when stress is applied. Therefore, it has advantages, such as a wider installation base and lower technological costs. In this study, a piezoelectric harvesting device imitating seaweed, which has a consistent motion caused by fluid, is used. Thus, it can regenerate electricity at sea or on a bridge pillar, which has a constant turbulent flow. The components of the device include circuitry, springs, an electric generator, and balancing and buoyancy elements. Additionally, multiphysics analysis coupled with fluid, structure, and piezoelectric elements is conducted using COMSOL Multiphysics to evaluate performance. Through this program, displacement and electric power were analyzed, and the actual performance was confirmed by the experiment.

• Journal of Preventive Medicine and Public Health
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• v.27 no.2 s.46
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• pp.242-257
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• 1994

In Korea, female workforce has reached more than 40% of total working population, but the effects of work on spontaneous abortion are yet to be examined. This study as conducted to investigate the occupational effects on spontaneous abortion. Medical insurance claim data were used to examine the effects of the employment status and industry of employment on spontaneous abortion. The study population was composed of females, aged $15{\sim}44$, who were the beneficiary of medical insurance in the month of June, 1993. The working females covered by medical insurance for industrial workers, had the highest age-adjusted Spontaneous Abortion rate (SAB rate=claim frequency of spontaneous abortion/claim frequency of complication of pregnancy, childbirth and the puerperium), 6.65% whereas female dependants of medical insurance for industrial workers had the lowest age-adjusted SAB rate, 4.54%. Among industrial workers, the workers in manufacturing industry had the highest age-adjusted Spontaneous Abortion ratio(SAB ratio=claim frequency of spontaneous abortion/claim frequency of completly normal delivery), 43.2/100 whereas those in financing and service industry had age-adjusted SAB ratio, 16.2/100 and 20.5/100, respectively. The results of the study suggest the adverse effect of manufacturing Industry on reproduction. Work environments such as chemical exposures, overwork, awkard posture, and job stress should be further studied for their effects on reproductive functions of female.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.1
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• pp.34-41
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• 2018

A flange joint is a pipe connection used to prevent the leakage of high-pressure fluids by inserting a gasket and tightening the bolts. Among several kinds of gaskets available, metal ring type joint gaskets are most widely used in conditions that require high-temperature and high-pressure fluid flow, such as oil pipelines, gas pipes, pumps, valve joints, etc. The purpose of this study is to investigate the contact pressure and stress characteristics closely related to the sealing performance of Class 900 flange joints used in high temperature and high pressure environments. The dimensions of flange joints with five different nominal pipe sizes were determined with reference to those specified in ASME 16.5. The metal ring gaskets inserted in the joints were octagonal and oval gaskets. The bolt tensile forces calculated from the tightening torques were input as the bolt pretension loads in order to determine the contact pressure and stress levels after fastening. Loading was composed of three steps, including the fastening step, and different amounts of applied pressures were used in each analysis to investigate the effect of fluid pressure on the contact force of the joints. A general-purpose software, ANSYS 17.2, was used for the analysis.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.4
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• pp.616-624
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• 2018

In this study, a previous DNPH (2,4-dinitrophenylhydrazine) coupled with high performance liquid chromatography (HPLC) method to measure the concentration of formaldehyde in ambient and source environments has been improved. To improve the disadvantage of the previous HPLC method, an appropriate composition ratio of mobile phase (water: acetonitrile (ACN)) was determined and an isocratic analysis was conducted. Furthermore, limit of detection (LOD), limit of quantitation(LOQ), accuracy, and precision were investigated to verify the reliability of the analytical conditions determined. Finally, samples of exhaust gases from five different industrial facilities were applied to HPLC analytial method proposed to determine their formaldehyde concentrations. The appropriate composition ratio of the mobile phase under the isocratic condition was a mixture of water(40%) and ACN(60%). As the volume fraction of the organic solvent ACN increases, retention time of the formaldehyde peak was reduced. Detection time of formaldehyde peak determined using the proposed isocratic method was reduced from 7 minutes(previous HPLC method) to approximately 3 minutes. LOD, LOQ, accuracy, and precision of the formaldehyde determined using standard solutions were 0.787 ppm, 2.507 ppm, 93.1%, and 0.33%, respectively, all of which are within their recommended ranges. Average concentrations of the formaldehyde in five exhaust gases ranged from 0.054 ppm to 1.159 ppm. The lowest concentration (0.054 ppm) was found at samples from waste gas incinerator in a bisphenol-A manufacturing plant. The highest was observed at samples from the absorption process in manufacturing facilities of chemicals including formaldehyde and hexamine. The analytical time of the formaldehyde in ambient air can be shortened by using the isocratic analytical method under appropriate mobile phase conditions.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.3
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• pp.190-198
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• 2018

The Epoxy-coated Reinforcing bars have been proved to be able to extend a durability life because of its excellent corrosion resistance in bridges and structures under marine and severe environments. The usage of epoxy-coated reinforcement is continuously increasing in developed countries such as the US and Japan. However, domestic use is extremely limited due to lack of research and development, poor production facilities, low quality, increase of initial costs, and difficulty of field management. This study suggests the improvement of construction quality management such as manufacturing, transportation and construction for the field application through the test construction of the proven product in the related test results of the epoxy coated steel bars produced in the recently improved manufacturing facility.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.68-72
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• 2004

A practical method to investigate the user interface of web based Flexible Manufacturing System(FMS) on the internet environment is established. Because the industrial FMS controller requires a lot of gadget, such as switch, dial, button, etc., for actual work-site flexible operation sufficiently, the user interface of the controller is significantly complex. The support for operational convenience of FMS controller can increase productivity and efficiency of the user, operational personnel of FMS. While most FMS provide their application programming interface(API) and graphical user interface(GUI) with adequate mechanism itself when used in stand alone, there is increasing demand for FMS that can operate with the intuitional user interface find virtual reality(V/R) environment. This thesis considers the intuitional user interface of Web-based FMS first, and from this, goes a step further, improves as virtual reality environment of FMS on the internet environments by using the feature based modeling technique approach and cartoon rendering. The feature-based modeling technique approach is applied to FMS line which is consist of facilities such as machining center, CNC lathe, autonomous guided vehicle, rail guided vehicle, and various controllers. In this study, the FMS established the intuitional user interface is able to obtain not only the operational convenience but also the enough productivity and significant efficiency.

• Journal of the Korean Geotechnical Society
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• v.36 no.8
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• pp.17-25
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• 2020

Korea Institute of Civil Engineering and Building Technology has constructed a large scale Dust Thermal Vacuum Chamber to simulate extreme lunar terrestrial environments and to study the Moon as an outposts for space development and exploration. Although a large amount of KLS-1 (Korean Lunar Simulant-1) is required for research, its massive production is practically difficult. This paper describes semi-automatic manufacturing system for massive production of KLS-1 in detail, which is seven times more efficient than manual production. In addition, to increase the similarity with lunar regolith, hydrogen reduction reaction using ilmenite which is one of the minerals was also conducted to simulate nanophase Fe(0) which is the unique property of lunar regolith. As a result, it was found that np-Fe(0) was formed at a temperature of 700℃ or higher, and increased in proportion to the temperature until 900℃.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.55-62
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• 2017

This paper aims to realize additional axes, which increase the processing efficiency of a robot by controlling in harmful environments. Ultimately, this is to create time and energy savings in industrial sites with 6-axis articulated welding robots (RS2). Using $RecurDyn^{(R)}$ a simulation technique is applied. The motion paths of the welding rod are compared for two cases in order to verify the necessity of the additional axes: 1) when there are no additional axes and 2) when there are additional axes during welding using the RS2. For this purpose, the angle variations of the RS2 axes required for the simulation are compared, on the assumption that each of the four points of the welding bed installed on the additional axes of the welding rod in $Solidworks^{(R)}$ is point-welded. Then, actual additional axes equipment is grafted on to the RS2 and the process times compared using $LabVIEW^{(R)}$.

• Nuclear Engineering and Technology
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• v.50 no.2
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• pp.223-228
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• 2018

AREVA NP (Courbevoie, Paris, France) is actively developing several enhanced accident-tolerant fuels cladding concepts ranging from near-term evolutionary (Cr-coated zirconium alloy cladding) to long-term revolutionary (SiC/SiC composite cladding) solutions, relying on its worldwide teams and partnerships, with programs and irradiations planned both in Europe and the United States. The most advanced and mature solution is a dense, adherent chromium coating on zirconium alloy cladding, which was initially developed along with the CEA and EDF in the French joint nuclear R&D program. The evaluation of the out-of-pile behavior of the Cr-coated cladding showed excellent results, suggesting enhanced reliability, enhanced operational flexibility, and improved economics in normal operating conditions. For example, because chromium is harder than zirconium, the Cr coating provides the cladding with a significantly improved wear resistance. Furthermore, Cr-coated samples exhibit extremely low corrosion kinetics in autoclave and prevents accelerated corrosion in harsh environments such as in water with 70 ppm Li leading to improved operational flexibility. Finally, AREVA NP has fabricated a physical vapor deposition prototype machine to coat full-length cladding tubes. This machine will be used for the manufacturing of full-length lead test rods in commercial reactors by 2019.