• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.4 s.181
• /
• pp.183-190
• /
• 2006

Digital 3D Real Object Duplication System (RODS) consists of 3D Scanner and Solid Freeform Fabrication System (SFFS). It is a device to make three-dimensional objects directly from the drawing or the scanning data. In this research, we developed an office type SFFS based on Three Dimensional Printing Process and an industrial SFFS using Dual Laser. An office type SFFS applied sliding mode control with sliding perturbation observer (SMCSPO) algorithm for control of this system. And we measured process variables about droplet diameter measurement and powder bed formation etc. through experiments. In case of industrial type SFFS, in order to develop more elaborate and speedy system for large objects than existing SLS process, this study applies a new Selective Dual-Laser Sintering (SDLS) process and 3-axis Dynamic Focusing Scanner for scanning large area instead of the existing f lens. In this process, the temperature has a great influence on sintering of the polymer. Also the laser parameters are considered like that laser beam power, scan speed, and scan spacing. Now, this study is in progress to evaluate the effect of experimental parameters on the sintering process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.14 no.3
• /
• pp.175-184
• /
• 2001

In this study, the improved throughput and stability in device fabrication could be obtained by applying CMP process to STi structue in 0.18 um semiconductor device. To employ the CMP process in STI structure, the Reverse Moat Process used to be added after STI Fill, as a result, the process became more complex and the defect were seriously increased than they had been,. Removal rate of each thin film in STI CMP was not uniform, so, the device must have been affected. That is, in case of excessive CMP, the damage on the active area was occurred, and in the case of insufficient CMP nitride remaining was happened on that area. Both of them deteriorated device characteristics. As a solution to these problems, the development of slurry having high removal rate and high oxide to nitride selectivity has been studied. The process using this slurry afford low defect levels, improved yield, and a simplified process flow. In this study, we evaluated the 'High Selectivity Slurry' to do a global planarization without reverse moat step, and also we evaluated EPD(Eend Point Detection) system with which 'in-situ end point detection' is possible.

• Journal of the Korean Society of Earth Science Education
• /
• v.2 no.1
• /
• pp.33-40
• /
• 2009

The purpose of this study is to examine the effect of higher grades in elementary the science process skill and Academic Achievement by IIM. To verify research problem, the subject of this study were five-grade students selected from One classes of an elementary school located in Ulsan : the experimental group is composed of thirty-four students who were participated in IIM teaching model situation. During six weeks, the IIM learning-based instruction was executed in th experimental group. Post-test showed following results: First, the experimental group showed a significant improvement in the science process skill. We look into detailly this, the experimental group showed a significant improvement in the basis science process skill. In particular, The sub-factor 'Observation', 'Measurement', 'expectation' of the science process skill effects a significant improvement. Second, the experimental group did showed a significant improvement in the Academic Achievement. In conclusion, IIM teaching model was more effective on science process skill and Academic Achievement. However, since the study has a limit on an objet of the study and the applied curriculum, the additional studies need to be conducted with an extended comparative group and curriculum.

• Korean journal of food and cookery science
• /
• v.19 no.1
• /
• pp.34-45
• /
• 2003

Backsulgi, the most basic type of rice cake, were prepared with the addition of process rice flour at 0%, 10%, 20%, 30%, 40% and their sensory quality and mechanical characteristics were compared. In addition, the changes in the sensory and textual characteristics of Backsulgi were determined while storing them at the temperatures of 4$^{\circ}C$ and 20$^{\circ}C$ for 0, 1, 2, and 3 days. As a result of sensory evaluation, Backsulgi with 30% process rice flour showed the highest score in overall quality, and the one with 10% process rice flour showed higher scores than controls. Backsulgi with process rice flour did not show significant differences in whiteness, graininess, sweet aroma, roasted nutty taste, sweet taste compared with the control even in the longer storage time at 4$^{\circ}C$ and 20$^{\circ}C$. In the measurement of color changes, L value (lightness) was not significantly different, but a value (redness) and b value (yellowness) were increased as the addition of process rice flour increased.

• Journal of Institute of Control, Robotics and Systems
• /
• v.6 no.1
• /
• pp.104-111
• /
• 2000

A fuzzy logic Run-by-Run(RbR) controller and an in -line wafer characteristics prediction scheme for the rapid thermal processing system have been developed for the study of process repeatability. The fuzzy logic RbR controller provides a framework for controlling a process which is subject to disturbances such as shifts and drifts as a normal part of its operation. The fuzzy logic RbR controller combines the advantages of both fuzzy logic and feedback control. It has two components : fuzzy logic diagnostic system and model modification system. At first, a neural network model is constructed with the I/O data collected during the designed experiments. The wafer state after each run is assessed by the fuzzy logic diagnostic system with featuring step. The model modification system updates the existing neural network process model in case of process shift or drift, and then select a new recipe based on the updated model using genetic algorithm. After this procedure, wafer characteristics are predicted from the in-line wafer characteristics prediction model with principal component analysis. The fuzzy logic RbR controller has been applied to the control of Titanium SALICIDE process. After completing all of the above, it follows that: 1) the fuzzy logic RbR controller can compensate the process draft, and 2) the in-line wafer characteristics prediction scheme can reduce the measurement cost and time.

• Journal of Welding and Joining
• /
• v.28 no.3
• /
• pp.42-48
• /
• 2010

Polycarbonate (PC) and Acrylonitrile Butadiene Styrene (ABS) were welded by a combination of a diode laser and a CNC machining center. Laser beam delivered through the transparent PC and was absorbed in an opaque ABS. Polymers were melted and joined by absorbed and conducted heat. Experiments were carried out by varying working distance from 44mm to 50mm for the focus spot diameter control, laser input power from 10W to 25W, and scanning speed from 100 to 400mm/min. The weld bead and cross-section were analyzed for weld quality, and tensile results were presented through the joint force measurement. With focus distance at 48mm, laser power with 20W, and welding speed at 300mm/min, experimental results showed the best welding quality which bead size was measured to be 3.75mm. The shear strength at the given condition was $22.8N/mm^2$. Considering tensile strength of ABS is $43N/mm^2$, shear strength was sufficient to hold two materials. A single process was possible in a CNC machining system, surface processing, hole machining and welding. As a result, the process cycle time was reduced to 25%. Compared to a typical process, specimens were fabricated in a single process, with high precision.

• Architectural research
• /
• v.18 no.1
• /
• pp.21-29
• /
• 2016

Importance of FM has rapidly increased because of its growing business. However, due to lack of clarity and identity of FM in professional areas, standardization of FM became to be imperative in such a rapidly changing global business environment. Facility services are defined as the provision of support the primary activities of an organization, delivered by an internal or external provider. Majority of FM activities are services related to 'space and infrastructure' and 'people and organization' (CEN, 2011). The purpose of this study is to investigate definitions and characteristics of FM from both globally and domestic environment, by comparison with international or national standards, to identify quality management in FM and service characteristics of FM, to investigate the differences in service level elaboration in FM, and to suggest standard issues of quality management in FM service quality. This study examines contents of the European Standards in FM, Part 3 'Guidance on quality in Facility Management, especially for the process of QM standardized by CEN (2011) and explores undefined issues such as service level, measurement metrics according to service characteristics of FM. The European FM Standard guides the common process of QM in terms of requirements specification, service level elaboration, measurement metrics development although it does not specifically address various service levels, specific performance metrics and indicators.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.12
• /
• pp.647-655
• /
• 2020

This study introduced income mobility analysis using pseudo-longitudinal panel data from Family Income and Expenditure Survey (FIES) to consider the dynamic process of individual's well-being through time. Since there is no comprehensive measurement of income mobility because of its dynamic process, various income mobility indices such as Chi-square, Average Jump Index, Atkinson et al. Mobility Ratio, and Shorrocks' Mobility Index were used. These indices revealed that Filipino households' income movements are more mobile than expected, and their income status improved from 2000 to 2015. As income mobility takes place, income inequality is reduced by 91.80 percent (91.80%). Furthermore, the growth effect is the main factor of income mobility. This indicates that households took the economic opportunities from economic growth to earn more. However, income mobility due to transfer effect (transfer of income from one household to another through lottery winning and borrowing) increased when the economy is not good. The higher income mobility due to growth effect compared to transfer effect, whether the economy is good or bad, means that households learned how to use their income in savings, investments, and entrepreneurship. This is the result of a successful financial literacy program of the government wherein households realized financial stability and security.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1666-1668
• /
• 2004

By wireless transmission data, there is high possibility to get distortion and lose by noise and barrier on wireless. If the data check damaged and lost at receiver, can't make it clear and can't judge whether this data is right or not. Therefore, by wireless transmission data need the data error check algorithm in order to decrease the data's distortion and lose and to monitoring the transmission data as real time. This study consists of RF station for wireless transmission, Water Level Meter station for water level measurement and Error check algorithm for error check of transmission data. This study is also that investigation and search for error check algorithm in order to wireless digital data transmission in condition of the least data's damage and lose. Designed transmitter and receiver with one - chip micro process to protect to swell the volume of circuit. Had designed RF transmitter - receiver station simply by means of ATMEL one - chip micro process in the systems. Used 10mW of the best RF power and 448MHz-449MHz on frequency band which can get permission to use by Frequency Law made by Korean government

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.23 no.3
• /
• pp.258-265
• /
• 2017

This paper validates a system identification method using mathematical optimization using sea trial measurement data as a benchmark. A fast time simulation tool, SIMOPT, and a Rheinmetall Defence mathematical model have been adopted to conduct initial hydrodynamic coefficient estimation and simulate ship modelling. Calibration for the environmental effect of sea trial measurement and sensitivity analysis have been carried out to enable a simple and efficient optimization process. The optimization process consists of three steps, and each step controls different coefficients according to the corresponding manoeuvre. Optimization result of Step 1, an optimization for coefficient on x-axis, was similar compared to values applying an empirical regression formulae by Clarke and Norrbin, which is used for SIMOPT. Results of Steps 2 and 3, which are for linear coefficients and nonlinear coefficients, respectively, was differ from the calculation results of the method by Clarke and Norrbin. A comparison for ship trajectory of simulation results from the benchmark and optimization results indicated that the suggested stepwise optimization method enables a coefficient tuning in a mathematical way.