• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.379-384
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• 2003

A turbo blower directly driven by a variable-speed BLDC motor was designed and tested to investigate performance characteristics. Computational analysis and performance tests validated the design method for the present turbo blower. Experimental measurements showed that the blower has an enough stability margin. This paper gives an outline of design, computational flow analysis and performance test for aerodynamic performance of the blower

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.6
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• pp.988-994
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• 1986

We present an automated CMOS standard cell design mehtodology which generates a mask description in the CIF (Caltech Intermediate Form)from a user-given logic description and design rule. The resultant layout reflects the user's choice among N-well, P-well and twin-well process and user's decision whether the guard band is to be included or not. Noise margin of each cell was improved by carefully adjusting the channel width of P-FET.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.3
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• pp.267-273
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• 2013

Recently, turbine-generators have been replaced for the integrity reinforcement and the efficiency improvement, also, the blade's failures of LP turbines due to torsional vibration have been reported. Excessive torsional vibrations can result in failures of components. The severity of torsional oscillations and stress depends upon the separation margin between the excitation frequencies and torsional natural frequencies. Therefore it is needed to measure the torsional natural frequencies after replacement of the components to conform the separation margin of torsional natural frequencies. In this study torsional vibration measurements were performed after LP turbine and generator replacement and the torsional natural frequencies for the turbine-generator train were calculated to evaluate the effects of generator replacement on torsional natural frequencies of turbine-generator train. It is expected that these evaluation results will be used effectively to identify the root causes of torsional vibration problems.

• Nuclear Engineering and Technology
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• v.26 no.2
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• pp.294-299
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• 1994

Margin benefits are quantatively assessed when a Digital Monitoring System(DMS) is assumed to be installed to an operating Westinghouse analog type plant. Applied plant and cycle is YongGwang Unit 1 Cycle 6. The referenced digital monitoring system is the COLSS (Core Operating Limit Supervisory System) of ABB-CE. Considered fuel design limits are DNBR and LDCA Fq. 2003-D Power distributions within the present CAOC (Constant Axial Offset Control) limits are calculated for the analysis. The most limiting DNB prevention event of CEA Withdrawal is analyzed with the ROPM (Required OverPower Margin) concept of ABB-CE. The result show that the DMS can bring around 7% more margins for both DNB and LOCA Fq standpoints of view. The DMS can also monitor the PCI (Pellet-Cladding Interaction) limits.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.4
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• pp.89-98
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• 2012

The purpose of this study is to female child Han-bok reform design for body growth. Nowadays there is common the western style daily life and special day instead of traditional style Han-bok in Korea. So the decrease in the use of Han-bok have being appeared. Specially, Children's Han-bok undesirable clothes for economic, environment, and resources because of their rapid growth and changing trend. Therefor, they do away with used Han-bok without next buying of school age. Children's parents and children are decision together purchase of children's Han-bok on-line for pleasure and economic reasons on pre-school or 1st year student for their tradition-education class. After 2000year, children's Han-bok pup-up on e-market because of the fashion focus on tradition and Korean wave for parody of Korean drama. Flowing the Research of 2010 Size Korea, the elementary school age child height growth 6cm per year, the sleeve length are 3cm growth. But Chi-ma(a pice of Han-bok) from e-market, has only 5cm margin on shoulder and no margin on Jegori(a pice of Han-bok) shoulder and sleeve, reason of that the children can't wear next year. Therefor this study is development female child Han-bok reform design for body growth, for extend to wear Han-bok on school age children and flow tradition custom of Cho-sun Dynasty's clothing custom for boost tradition conscious and reduce of cloth waste for environment.

• Journal of Industrial Convergence
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• v.16 no.2
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• pp.33-39
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• 2018

This paper describes the design method of the linear PID controller and proposed the design method in the future. The first PID design method is to ensure phase margin and gain margin. This method guarantees stability by designing in the frequency domain. The second method is an internal model control method. This method is to design the PID controller using the parameters of the internal model after identifying the internal model for the control model. Therefore, this method has a strong disturbance characteristic. Finally, a proposed Cascade and smith-Predictor controller. The combination of the cascade controller and the smith-predator of this method is a controller structure that has two advantages: robust control and optimal control. This method can obtain the performance evaluation index as the optimal controller design method. This PID controller design method becomes the basis of the nonlinear method and is being continuously studied.

• Journal of Korean Dental Hygiene Science
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• v.5 no.1
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• pp.13-19
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• 2022

Background: In this study, zirconia copings were fabricated by setting clinically acceptable inner values for prostheses using computer-aided design/computer-aided manufacturing (CAD/CAM). The processed copings were evaluated for the marginal and internal fit of each abutment shape with a CAD program using the silicone replica technique. Methods A total of 20 copings was produced by selecting models commonly used in clinical practice. After injecting the sample, the minimum thickness, internal adhesion interval, and distance to the margin line were set to 0.5, 0.05, and 1.00 mm using a dental CAD program, respectively. It was measured using a 2D section function in a three-way program of the silicon replication technology. Although the positions and number of measurements of the anterior and posterior regions differed, nine parts of each pre-tube were designated and measured by referring to a previous study to compare the two samples. Results As a result, the average margin of the mesial, distal, and buccal (labial) surfaces was 59.90 ㎛ in the anterior region and 60.40 ㎛ in the posterior region. The mean axial wall margin was 67.25 ㎛ in the anterior region and 69.25 ㎛ in the posterior region. In occlusion, the anterior teeth (77.70 ㎛), posterior teeth (77.60 ㎛), and both anterior and posterior regions were within the clinically acceptable range. Conclusion The edge and inner fit of zirconia coping manufactured using the CAD/CAM system showed clinically applicable results. To reduce errors and increase accuracy, materials and machine errors that affect the manufacture of prosthetics should be investigated. Based on our results, the completeness of prosthetics could increase if the inner value and characteristics of the material are adjusted when applied in clinical practice.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.10 s.113
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• pp.929-934
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• 2006

In the paper, we suggest a simpler synthesis technique for capacitively-coupled match circuit(CCMC) which have a function of DC block and impedance matching simultaneously, and introduce a stability margin analysis technique for designing microwave amplifier under conditionally stable state. Stability margin analysis is used to determine optimum match point that ensure maximum gain under the given stability margin. It can reduce time consuming work for selecting match points in the conditionally stable state. Also, suggested miniaturization scheme of matching network is distinguished from previous work with respect to reducing deterministic parameters for CCMC synthesis. To verify utility of suggested method, 24 GHz gain block is fabricated under conditionally stable state using an internal thin-film fabrication process, Measured results show a stable gain of 10 dB and flatness of 1 dB, which is well coincident with simulated one.

• Journal of IKEEE
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• v.1 no.1 s.1
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• pp.11-18
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• 1997

By utilizing the technique to monitor the DC cell node voltages through circuit simulation, degradation of the static read operating margin In high load-resistor SRAM cell was examined, which is caused by parasitic resistances and transistor asymmetries in this cell structure. By selectively adding the parasitic resistances to an ideal cell, the influence of each parasitic resistance on the operating margin was examined, and then the cases with parasitic resistances in pairs were also examined. By selectively changing the channel width of cell transistors to generate cell asymmetry, the influence of cell asymmetry on the operating margin was also examined. Analyses on the operating margins were performed by comparing the supply voltage values at which two cell node voltages merge to a single value and the differences of cell node voltages at VDD=5V in the simulated node voltage characteristics. By determining the parasitic resistances and the transistor asymmetries which give the most serious effect on the static read-operation of SRAM cell from this analysis based on circuit simulated, a criteria was provided, which can be referred in the design of new SRAM cell structures.

• The KIPS Transactions:PartD
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• v.9D no.1
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• pp.167-172
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• 2002

Recently, some of people are keep in research and development of the further more efficient and convenient auction systems using intelligent software agents in electronic commerce. The purpose of this thesis is that a simple auction system has web bulletin boards, is aided by intelligent agent, and generates pertinent auction duration time and starting price for auction goods of auctioneer into a auction system, then the auctioneer gets the highest margin. The seller who want to sell goods, is using internet sends mail that has information for goods to agent of internet auction system. The agent undertake filtering process for already learned information about similar goods. And it calculate duration time and start price from stored bidding history database. In this thesis we propose a mailing agent system pushing information in internet auction that enables to aid decision for auctioneer about the starting time and price which delivers the highest margin.