• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.58 no.4
• /
• pp.585-587
• /
• 2009

A large diameter slot waveguide made backward wave oscillator is investigated experimentally. The parameters of slow wave structure are chosen so that the oscillation frequency is about 20 GHz. Plasma is produced by the beam and it has favorable effects on beam propagation and Cherncov oscillation. The output power strongly enhanced when the guiding magnetic field approaches to the fundamental electron cyclotron resonance.

• Proceedings of the Korean Society for Quality Management Conference
• /
• 2006.04a
• /
• pp.313-318
• /
• 2006

Many control charting methods for both i.i.d and autocorrelated data can be viewed as charting the output of a linear filter applied to the process data. We propose a generalization of this concept, in which the filter parameters are optimally selected to minimize the out-of-control ARL while constraining the in-control ARL to some desired value. A number of interesting characteristics of the optimal fitters are discussed.

• International Journal of Quality Innovation
• /
• v.8 no.3
• /
• pp.173-187
• /
• 2007

Many 6-sigma innovation companies are obtaining ISO9000 series or ISO/TS16949 certifications. However, not many of them have considered the integrated management of ISO/TS16949 at the time of 6-sigma introduction. ISO/TS16949 focuses on the process of an overall company. In particular, APQP (Advanced Product Quality Planning) requires that from the beginning all the planning should have a clear quality planning business process. Each company can decide the best course of action to suit its individual needs. Lean DFSS in 6-sigma offers the concrete development steps of the product development process. And if analyses of Input, Output, Target, Process, KSF, KPI, and FMEA is done in each process and clearly defined in APQP, mutual organic and effective systems can be initially achieved.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.11
• /
• pp.1946-1953
• /
• 2008

Power system of Jeju is interconnected to the mainland using HVDC and that is also interconnected to three wind farms. It will be difficult to control of Jeju power system if HVDC is disconnected or HVDC is overhauled under large scale wind farms interconnected. We measured and analysed the power quality of two substation and two wind farms to assess that wind farms have an effect on Jeju system during the HVDC overhaul last May. We concentrated on the power quality like frequency, voltage variation, voltage harmonics, current harmonics, flicker. We can found that the frequency of Jeju system is very unstable during overhaul, so the frequency of Jeju system can be variated easily by wind farm's rapid output power variation. There are some benefits and weak points in power quality between two wind farms because each wind farm is consist of different wind turbines.

• Korean Journal of Optics and Photonics
• /
• v.5 no.1
• /
• pp.60-66
• /
• 1994

First, the beam waist size of TE$M_{00}$ Nd:YAG laser mode with Positive Branch Unstable Resonator was calculated. and then, the output power, fundamental mode and multimode beam quality factor of PBUR were measured and compared with thouse of reference resonator with plane pallalel mirrors. In characterizing the beam quality, the $M^2$ concept was used. The focusability of laser beam in unstable resonators was discussed with this $M^2$.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.10a
• /
• pp.310-314
• /
• 2008

The exploitation of the wind energy resource is a rapidly growing area world-wide. The number of installed units is continuously increasing, and it is important to respect and to deal with the impact of wind turbine. This paper addresses the power quality characteristics of U57 Wind Turbine. 750kW gearless type wind turbine for low wind speed, named U57, is developed by UNISON. The power quality measurement system consists of measuring WTG output current, line-to line voltage and wind speed signal. With using measured data, power quality measurement is evaluated about maximum power, reactive power, voltage fluctuation, harmonics according to IEC 61400-21.

• Progress in Medical Physics
• /
• v.15 no.4
• /
• pp.237-246
• /
• 2004

Even though the wedge factor was defined by ICRU, RTPS uses other definition different from the wedge factor to consider the wedge effect to correct dose. Because the factors with different concept are defined in a very different way, replacement of different factor could make severe error of dose and is unacceptable because their values are very different from each other. Radiotherapy machine installed in department includes physical wedges and function of dynamic wedge by upper jaws, and Eclipse and Pinnacle$^{3}$ such as RTPS are used. The wedge factors, relative wedge output factors and wedge field output factors of physical wedges and dynamic wedges were measured by an ionization chamber in water phantom. They are analyzed and compared in according to wedge position, field size, wedge angle, X-ray quality, measurement condition. Wedge factor, relative wedge output factors and wedge field output factors of dynamic wedges comparing physical wedges have an effect of several factors. Main factors effecting to the factors of dynamic wedges were field size and wedge angle. Beam quality of X-ray introduces a few effect to the factors. Because the factors related to wedge and defined with different concepts are different from each other, to reduce dose error it should be input by values proper to RTPS.

• Journal of Construction Engineering and Project Management
• /
• v.5 no.2
• /
• pp.24-34
• /
• 2015

The complexity arises in defining the construction quality due to its perception, based on inherent market conditions and their requirements, the diversified stakeholders itself and their desired output. A quantitative survey based approach was adopted in this constructive study. A questionnaire based survey was conducted, for the assessment of construction quality perception and expectations in the context of quality improvement technique. The survey feedback of professionals, from the leading construction organizations/companies of Pakistan were analyzed. The financial capacity, organizational structure, and construction experience of the construction firms formed basis for their selection. After statistical analysis of survey feedback it was found reliable and valid for the inferential purpose to the target population of construction professionals. The quality perception was found to be project scope oriented, considered as an excess cost for a construction project and keeping the rework minimum by qualifying the required quality tests, keeping the defects minimum by ensuring the specifications of supplied material. Any quality improvement technique was expected to address the financial aspects of the construction project for the employer and contractor, by increasing the profitability through reduction in overall cost, reduction in time, reduction in defects and improving the productivity in a construction project. The study is beneficial for the construction professionals to assess the prevailing construction quality perception and the expectations from implementation of any quality improvement technique in construction projects.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.26 no.1
• /
• pp.7-16
• /
• 2003

At present, company has to produce a product that consumer like with a competitive price, a good quality, and a fitting time to supply. Process control and quality control are very important to supply with a product uniformly and inexpensively. Process control is given much weight in the quality control in manufacturing system. Statistical process controls(SPC) that are used in process generally have major impact on manufacturing, product design activities, and process development potentially. Control charts in statistical process control method can be interpreted the data from quality characteristics in production process and discriminated between chance variation and assignable variation in process. In addition, control chart can be used to monitor the process output and detect when changes in the inputs are required to bring the process back to an in-control state. The models that relate the influential inputs to process outputs help determine the nature and magnitude of the adjustments required. In this paper, the characteristic of product quality is monitored by control chart during the machining process and construction of quality control cycle is considered to divide into two types in this case that different assignable causes lead to shifts having different magnitudes. Then we are intended to find a process shift magnitude which has economical quality cost policy and are considered to quality cost functions to find a process shift magnitude. Those costs are categorized into the well-known categories of prevention, appraisal, and internal failure and external failure. This paper ends with numerical examples that demonstrate the usefulness of the model.

• Journal of Korean Institute of Industrial Engineers
• /
• v.43 no.2
• /
• pp.90-99
• /
• 2017

As the importance of R&D has increased, there have been various efforts to apply the quality management principles and tools to R&D activities in order to manage them effectively. The R&D sector differs from other value chains, so it may be difficult to apply quality management without proper considerations of R&D characteristics. This study describes the characteristics of R&D as high uncertainty and risk, diversity of R&D types, project-based activities, importance of strategic goals and business models, and importance of intangible assets. Three well accepted R&D quality management models are reviewed and implications for quality management and R&D characteristics are summarized. Based on these findings, the management targets of R&D quality management are classified into management level (organization, project) and management focus (process, output), and the contexts of R&D quality management are classified into R&D type (research, development) and market/customer requirement clarity (fluid, specific), and appropriate R&D quality management activities in each situations have been suggested.