• Journal of Welding and Joining
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• v.14 no.3
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• pp.75-85
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• 1996

In this paper the influence of postweld heat treatment on mechanical properties of SMAW and FCAW stainless steel weldments was examined and the obtained results are as follows ; (1) The amount of $\delta$-ferrite formed by SMAW and FCAW process decreased with increasing holding temperature and time in post weld heat treatment(PWHT), and it was found that the reduced ferrite was transformed into sigma phase after $800^{circ}C{\times}50hr$ PWHT. This sigma phase, even though it was very small, resulted in brittleness of dissimilar weldment between carbon steel and stainless steel in bending test, however in similar weldment between stainless steel and stainless steel was not occured. (2) The chemical composition of sigma phase was measured to 28-30%Cr, 7-9%Mo, 4-6Ni in 316L weldment, and also 35-37%Cr, 0.9-1.0Mo, 6-8%Ni in 309L weldment by EDS analysis.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.3
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• pp.438-445
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• 2017

This paper presents a low-power high-resolution band-pass ${\Sigma}{\Delta}$ ADC for accelerometer applications. The proposed band-pass ${\Sigma}{\Delta}$ ADC consists of a high-performance 6-th order feed-forward ${\Sigma}{\Delta}$ modulator with 1-bit quantization and a low-power, area-efficient digital filter. The ADC is fabricated in 180 nm 1P6M mixed-signal CMOS process with a die area of $5mm^2$. This high-resolution ADC got 90 dB peak signal to noise plus distortion ratio (SNDR) and 96 dB dynamic range (DR) over 4 kHz bandwidth, while the intermediate frequency (IF) is shifting from 100 KHz to 200 KHz. The power dissipation of the chip is 5.6 mW under 1.8 V (digital)/3.3 V (analog) power supply.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.649-659
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• 2006

Recently there has been huge efforts to improve performance in construction process by applying emerging techniques such as the Lean principle and Just-in-time concept. However, little achievement as we expected has come out in reality due to the lack of strategy to set a definite goal of the execution and differences of personal viewpoints on construction productivity. Accordingly, it is the most important to promote the circumstances for the construction process improvement by quantifying the goals of respective unit activity groups. This research explores feasible solutions for the improvement of construction projects performance by combining the six-sigma principle for the generic administrative innovation based on the idea of construction process performance. For this purpose, mutual comparisons of various current approaches are performed in an attempt to establish the advantages in applying six-sigma idea and to provide its fundamental strategy. Furthermore, through a case study with the simulation of applying six-sigma to a unit activity group in construction process, this paper verifies that the overall performance improves as the degree of sigma level gets advanced.

• International Journal of Automotive Technology
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• v.6 no.6
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• pp.625-633
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• 2005

Vehicle drift was reduced using statistical six sigma tools. The study was performed through four steps: M (measure), A (analyze), I (improve), and C (control). Step M measured the main factors which were derived from a fishbone diagram. The measurement system capabilities were analyzed and improved before measurement. Step A analyzed critical problems by examining the process capability and control chart derived from the measured values. Step I analyzed the influence of the main factors on vehicle drift using DOE (design of experiment) to derive the CTQ (critical to quality). The tire conicity and toe angle difference proved to be CTQ. This information enabled the manufacturing process related with the CTQ to be improved. The respective toe angle tolerance for the adjustment process was obtained using the Monte Carlo simulation. Step C verified and controlled the improved results through hypothesis testing and Monte Carlo simulation.

• The KIPS Transactions:PartD
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• v.14D no.1 s.111
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• pp.45-56
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• 2007

As the knowledge-based society has been constructed, the size of work process that has to be done grows bigger and the amount of the information that has to be analyzed increases. So each company is trying to construct more conformable process models in business model. This study helps to understand the interaction between Process data and structure which are collected on the profess by appling six Sigma as a process improving methodology. On Six Sigma, businesses tn practice Best Practice Process with the view of Value Chain To measure data for the process performing action, introducing Schedule management method makes it possible to collect and reflect accurate data of workers' ability. By this method, efficiency in production will be improved because workers we able to perform the process correctly and preliminary management for defects.

• Journal of the Korea Safety Management & Science
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• v.11 no.2
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• pp.205-214
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• 2009

Today, many of communication methods based on print media traditionally has moved to the internet. As increase of interest in internet business, effective web site design is needed. While the researches for the evaluation of completed web site are increased, that of web site design procedures are rare. In the design process occur various problems : rework, delay, etc.. In this paper are presented the improved procedures of web site design using 6 sigma methodology. The main object of this study is to introduce an empirical study on DIDOV.

• Journal of the Semiconductor & Display Technology
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• v.7 no.4
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• pp.23-28
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• 2008

A high speed automated pitch variation unit (HAPU) related to semiconductor category sorting movement of the test handler system was developed. In the design process, 'DMADOV' step of 6-Sigma method has been applied. The design result for the desirable pitch variation was a 3:1 reduction rack-pinion and a linkage which are operated by servomotors. The realization and reliability of the mechanism was obtained at the design stage by FEM analysis, and by robust design using Taguchi orthogonal array against weight and deformation. Finally, the validity of the high speed variation mechanism was confirmed via inspection using a high speed camera while performing pitch variation.

• Korean Journal of Oriental Medicine
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• v.12 no.2 s.17
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• pp.85-92
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• 2006

Pulse is one of the basic diagnostic information of TKM(Traditional Korean Medicine). To quantify and standardize pulse diagnosis, we had collected an amount of clinical data from May 2005 by using newly developed pulse analyzer. But there were many noises in pulse wave according to measuring method, environment, operator and condition of patient. So some data can’t be included for analyzing diagnosis. To reduce noises from measuring pulse and to collect reliable pulse wave data, we made the process map of measuring method and applied six sigma project. With this we can improved the method of measuring pulse wave in collecting clinical data. The project follows a disciplined process of five macro phases: define, measure, analyze, improve and control (DMAIC). A process map and C-E diagram are used to identify process input and output variables. The major input variables are selected by using C&E matrix, and process map is developed by analyzing input variables. And the optimum process conditions are going to be controled to avoid in increasing loss of collecting pulse wave data.

• Journal of Korean Society for Quality Management
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• v.38 no.2
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• pp.180-189
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• 2010

For the success of total six sigma innovation, it is necessary to improve the suppliers' quality in the supply chain. This paper presents the deployment and support system of six sigma innovation for supply chain quality improvement, with the application to an aerospace production company. The process of project selection, project implementation, financial effect verification, benefit sharing is presented. This paper will benefit the companies which are going to enhance all the companies in the supply chain via six sigma activities.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.12
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• pp.86-94
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• 1997

This paper proposes the robot inverse calibration method using a neural networks. A high-order networks called Pi-Sigma networks has been used. The Pi-Sigma networks uses linear summing units in the hidden layer and product unit in output layer. The inverse calibration model which compensates the diff- erence of joint variables only between measuring value and analytic value about the desired pose(position, orientation) of a robot is proposed. The compensated values are determined by using the weights obtained from the learning process of the neural networks previously. To prove the reasonableness, the SCARA type direct drive robot(4-DOF) and anthropomorphic robot(6-DOF) are simulated. It shows that the proposed calibration method can reduce the errors of the joint variables from .+-. 5 .deg. to .+-. 0.1 .deg. .