• Journal of the Korean Professional Engineers Association
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• v.24 no.5
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• pp.129-137
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• 1991

In case a firm proceeds with TQC the activity of QCC, one of the activities concerned with TQC, is made first of all. There fore, in consideration that TQC could not be successful with the activity of QCC being unsuccessful a firm underlines activating QCC and makes considerable support of the educational discipline. However, as for the data of TQC having been introduced in domestic country no data related to construction industry have been found, all of them being concerned with manufacturing industry and it has happened that some firms of the construction industry make the negative reaction to the activity of QCC. So some of firms including our one have prepared and published their own texts and made them available by utilizing the translated Japanese data which were attained through Japanese construction firms. It is thought that a problem has been caused by the above-stated. While Japanese firms have made R & D of the features concerning to the most basic QCC activity for themselves, Korean ones have just followed and taken advantage of those originated by Japanese without being conscious of the basic idea, and this has caused the consequent failing of QCC activity. In other word, the emphasis of the results only rather than process has brought about the unsuccessful QCC activity.

• KIEAE Journal
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• v.10 no.3
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• pp.89-96
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• 2010

In comparison with ordinary or heavy-weight concrete, light-weight air void concrete has the good aspects in optimizing super tall structure systems for the process of design considering wind load and seismic load by lightening total dead load of buildings and reducing natural resources used. Light-weight air void concrete has excellent properties of heat and sound insulating due to its high amount porosity of air voids. So, it has been used as partition walls and the floor of Ondol which is the traditional Korean floor heating system. Under the condition of which the supply of light-weight aggregates are limited, the development of light-weight concrete using air voids is highly required in the aspects of reduced manufacturing prices and mass production. In this study, we investigated the physical properties and thermal behaviors of specimens that applied different mixing ratios of foaming agent to evaluate the possibility of use in the structural elements. We proposed the estimating equation for compressive strength of each mix having different ratio of foaming agent. We also confirmed that the density of cement matrix is decreased as the mixing amount of foaming agent increase up to 0.6% of foaming agent mixing ratio which was observed by SEM. Based on porosity and compressive strength of control mortar without foaming agent, we built the estimating equations of compressive strength for mortars with foaming agent. The upper limit of use in foaming agent is about 0.6% of the binder amount. Each air void is independent, and size of voids range from 50 to $100{\mu}m$.

• Korean Journal of Materials Research
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• v.23 no.8
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• pp.453-461
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• 2013

Controlling the stick and slip motions of the contact lines in a confined geometry comprised of a spherical lens with a flat substrate is useful for manufacturing polymer ring patterns. We used a sphere on a flat geometry, by which we could control the interfaces of the solution, vapor and substrate. By this method, hundreds of concentric ring-pattern formations of a linear conjugated polymer, poly [2-methoxy-5-(2-thylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), were generated with excellent regularity over large areas after complete solvent evaporation. Subsequently, the MEH-PPV ring patterns played a role as a directed template to organize highly regular concentric rings of single-walled carbon nanotubes(SWCNTs); when a droplet of the SWCNT suspension in water was casted onto the prepared substrate, hydrophobic polymer patterns confined the water dispersed SWCNTs in between the hydrophilicized $SiO_2/Si$ substrate. As the solvent evaporated, SWCNT-rings were formed in between MEH-PPV rings with controlled density. Finally, we used a lift-off process to produce SWCNT patterns by the removal of a sacrificial polymer template with organic solvent. We also fabricated a field effect transistor using self-assembled SWCNT networks on a $SiO_2/Si$ substrate.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.66.3-67
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• 2016

The Giant Magellan Telescope (GMT) will feature two interchangeable Gregorian secondary mirrors, an adaptive secondary mirror (ASM) and a fast-steering secondary mirror (FSM). The FSM has an effective diameter of 3.2 m and built as seven 1.1 m diameter circular segments, which are conjugated 1:1 to the seven 8.4m segments of the primary. Each FSM segment contains a tip-tilt capability for fine co-alignment of the telescope subapertures and fast guiding to attenuate telescope wind shake and mount control jitter. This tip-tilt capability thus enhances performance of the telescope in the seeing limited observation mode. As the first stage of the FSM development, KASI conducted a Phase 0 study to develop a program plan detailing the design and manufacturing process for the seven FSM segments. The GMTO-KASI team matured this plan via an internal review in May 2016 and the revised plan was further assessed by an external review in June 2016. In this poster, we present the technical aspects of the FSM development plan.

• Journal of Ocean Engineering and Technology
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• v.24 no.6
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• pp.71-75
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• 2010

Although Graphite Compacted Vermicular (GCV) was first observed in 1948, the narrow range for stable foundry production precluded the high volume application of GCV to complex components such as cylinder blocks and heads until advanced process control technologies became available. This, in turn, had to await the advent of modern measurement electronics and computer processors. Following the development of foundry techniques and manufacturing solutions, primarily initiated in Europe during the 1990s, the first series production of GCV cylinder blocks began during 1999. Today, more than 40,000 GCV cylinder blocks are produced each month for OEMs, including Audi, DAF, Ford, Hundai, MAN, Mercedes, PSA, Volkswagen, and Volvo. Given that new engine programs are typically intended to support three to four vehicle generations, the chosen engine materials must satisfy current design criteria and also provide the potential for future performance upgrades without changing the overall block architecture. With at least a 75% increase in the ultimate tensile strength, a 40% increase in the elastic modulus, and approximately double the fatigue strength of either iron or aluminum, GCV is ideally suited to meet current and future of engine design and performance requirements.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.2
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• pp.101-111
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• 2012

In the ALC(Autoclaved lightweight concrete) manufacturing process, if the pre-cured semi-cake is removed after proper time is passed, it will be hard to retain the moisture and be easily cracked. Therefore, in this research, we took the research by multiple regression analysis to find relationship between variables for the prediction the hardness that is the control standard of the removal time. We study the relationship between Independent variables such as the V/T(Vibration Time), V/T movement, expansion height, curing time, placing temperature, Rising and C/S ratio and the Dependent variables, the hardness by multiple regression analysis. In this study, first, we calculated regression equation by the regression analysis, then we tried phased regression analysis, best subset regression analysis and residual analysis. At last, we could verify curing time, placing temperature, Rising and C/S ratio influence to the hardness by the estimated regression equation.

• Journal of the Korea Society for Simulation
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• v.17 no.3
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• pp.75-83
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• 2008

A deadlock is a condition in which the excessive demand for the resources being used by others causes activities to stop and it is one of the important problems in process control system to detect and prevent deadlocks. While the reachability analyze methods or divide subnets for analyzing methods are well used, it requires a lot of times and effects to analyze the detection of the deadlock status. Furthermore, it could not be effective if the model is complex or huge. Therefore, it is necessary to develop a new and more efficient deadlock detection algorithm. In this paper, a deadlock detection conditions after analyzed the Petri Net using the transitive matrix has been proposed to solve these problems. For presenting the results, the suggested deadlock detection algorithm was also adapted to an illustrated FMS (Flexible Manufacturing System) model.

• Korean Journal of Optics and Photonics
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• v.28 no.2
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• pp.75-82
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• 2017

We present a new type of receiver-transmitter optical system that can be adapted to the sensor head of a displacement-measuring interferometer. The interferometer is utilized to control positioning error and repetition accuracy of a wafer, down to the order of 1 nm, in a semiconductor manufacturing process. Currently, according to the tendency of scale-up of wafers, an interferometer is demanded to measure a wider range of displacement. To solve this technical problem, we suggest a new type of receiver-transmitter optical system consisting of a GRIN lens-Collimating lens-Afocal lens system, compared to conventional receiver-transmitter using a single collimating lens. By adapting this new technological optical structure, we can improve coupling efficiency up to about 100 times that of a single conventional collimating lens.

• Journal of Korean Society for Quality Management
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• v.39 no.4
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• pp.527-542
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• 2011

The importance of service industry in national economy is getting increasing due to current trend of aging society and increasingly desire for better quality of life. However, the level of labor productivity in domestic service industry is lower than Japan and Germany that are typically strong in manufacturing industry. Difficulty of process control and measurement in accordance with variability and intangibility which are features of service industry, is considered as the cause of this poor labor productivity in Korea. This study aims to present managerial implications by calculating sigma levels on branch bank service quality and suggesting the quality dimensions of banks can be checked through a gap comparison between the sigma level on service quality in the whole banks and service quality in each bank. Quality level presented by the KS-SQI is applied to the measurement method that Yoo Han Joo and Song Kwang Seok suggested in 2006. Spss18.0 is used as an analysis tool. As a result of factorial analysis, 7 dimensions of service quality in KS-SQI can be divided into new 3 dimensions of service quality. This study also suggests that width and number of questions in previous questionnaire shall be extended. The whole of the bank service quality level is evaluated 3 sigma. The research help banks to figure out their service quality level through gap comparison objectively.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.60-60
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• 2010

Since the curved hull plate was made by a series of manufacturing process including cold bending, manual local heating and correction work, the accuracy of curved plate strongly depends on the proficiency of worker. So the demands on the automatic local heating system for curved hull plate have continuously increased and the various researches relevant to it have been performed. Generally, the heat sources used for local heating were flame and induction heat. In terms of initial cost, flame heating is in a better favorable position than induction heating. However, from the viewpoint of the control of heat, induction heating has more advantage. So the various researches related to apply the induction heating to the automatic forming system has been performed. The purpose of this study is to establish the proper capacity of high frequency induction heating system for forming the curved hull plate. In order to do it, the proper coil shape for local heating was designed and the efficiency of induction heating system was determined by comparing of temperature results obtained by FEA and experiment. With the results, the extensive FEA was performed to identify the effect of heated plate dimension, cooling method and the capacity of induction heating system on the amount of heat loss introduced by induction heating. Based on the results, the proper capacity of high frequency induction heating system was proposed.