• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.12
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• pp.1572-1580
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• 1995

In this paper, a modified Chebyshev low-pass filter function is proposed. The modified Chebyshev filter function exhibits ripples diminishing toward .omega. = 0 in the passband. So, the modified filter function is realizable in the passive doubly-terminated ladder network for the order n even or odd, thus lending itself amenable to active RC or switched capacitor filters through the simulation techniques. Besides the passive doubly-terminated ladder realizability, lower pole-Q values of the modified function are accountable for improved phase and delay characteristics, as compared to classical function. We have designed the 6th order passive doubly-terminated network using the modified function. And then a continuous-time DDA(Differential Difference Amplifier) filter, which has no matching requirement, is realized by leap-frog simulation technique for fabrication. In the HSPICE simulation results, we confirmed that the designed continuous-time DDA filter characteristics are agreement with the passive filter.

• KCID journal
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• v.11 no.1
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• pp.36-44
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• 2004

The objective of this study is to analyze the characteristics of the nutrients loading and the water purification function in the paddy-fields. This study was carried out based on the research data in the three case studies. 1. Irrigation requirement is m

• Communications of the Korean Mathematical Society
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• v.33 no.3
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• pp.823-831
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• 2018

We define progressive tax rate functions, study their properties, and describe some smooth models. The key requirement, defining the progressive nature of the taxation model, is that the progressive tax rate functions should have infinite contact with the zero function at the origin, in order to care the poor. In constructing a wide array of such functions, assisting functions are introduced.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.1
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• pp.113-126
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• 1992

It is discussed how a supplier should design a quantity discount pricing schedule for multiple buyers. It is emphasized that nor only the supplier's surplus but also each buyer's surplus resultant from quantity discount should be considered in designing price schedule. It is shown that if the supplier's quantity pricing schedule is based on his/her profit function, each buyer's surplus may be maximized. And it is also shown that when the supplier's main benefit comes from the reduced number of setups, the incremental discount schedule satisfies the requirement. Formulas to determine values of parameters of the incremental discount schedule are provided.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.43-49
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• 2010

Aerodynamic design of the vane type multi-function probe was tried by using CFD and wind tunnel test for the MALE UAV and small business jets. The present multi-function probe can measure total pressure, static pressure and angle of attack by using rotating vane. Therefore major performances are determined by aerodynamic characteristics of vane. In oder to design the sensor compatible to the requirement, aerodynamic characteristics of sensors was investigated by using CFD and dynamic response analysis was also performed for trasient performance. The final aerodynamic performance was measured by the wind tunnel test at Aeorsonic and the results successfully used for the design of vane type multi-function air data sensor.

• Journal of computational fluids engineering
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• v.15 no.3
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• pp.32-38
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• 2010

Aerodynamic design of the vane type multi-function probe was tried by using CFD and wind tunnel test for the MALE UAV and small business jets. The present multi-function probe can measure total pressure, static pressure and angle of attack by using rotating vane. Therefore, major performances are determined by aerodynamic characteristics of vane. In order to design the sensor compatible to the requirement, aerodynamic characteristics of sensors were investigated by using CFD and dynamic response analysis was also performed for transient performance. The final aerodynamic performance was measured by the wind tunnel test at Aerosonic and the results were compared with the present design. The results showed that the aerodynamic design using the CFD can be successfully used for the design of vane type multi-function air data sensor.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.4
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• pp.673-682
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• 2010

This paper describes and analyzes a various generation methods of the mutually orthogonal polyphase sequences with low cross-correlation peak sidelobe and low autocorrelation peak sidelobe levels. The mutual orthogonality is the key requirement of multi-static or MIMO(Multi-Input Multi-Output) radar systems which provides the good target detection and tracking performance. The polyphase sequences, which are generated by SA(Simulated Annealing) and GA(Genetic Algorithm), have been analyzed with ACF(Autocorrelation Function) PSL(Peak Sidelobe Level) and CCF(Crosscorrelation Function) level at the matched filter output. Also, the ambiguity function has been introduced and simulated for comparing Doppler properties of each sequence. We have suggested the phase selection rule for applying multi-static or MIMO systems.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.975-977
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• 2004

According to thin and light form-factor and additional function of today's electronic devices, it is required to decrease the pattern pitch of FPC. The high density demand is more and more important trend especially, for small size LCD module. Based on this requirement, the manufacturing process is advancing from subtractive method to super subtractive method.

• Journal of KIISE
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• v.42 no.9
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• pp.1117-1123
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• 2015

Use The Use Case Points method is a software estimation method that is based on user requirements. When requirement analysts elicit user requirements, they obtain different use cases because different levels of detail are possible for the Use Case, and this affects the Use Case Points. In this paper, we suggest a method to refine the level of detail of the Use Case by using the concept of an elementary function. This refinement method achieves the desired reliability for the Use Case Points because it produces less of a deviation in the Use Case Points for different requirement analysts than other methods that are based on the step, transaction, and narrative of the Use Case.

• Journal of the Korean Society of Systems Engineering
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• v.15 no.2
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• pp.57-65
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• 2019

The weapon system applies the rule that the system engineering procedure must be applied at the acquisition stage. Naval ships, which are one of the important naval weapon systems, take a long period of time to acquire, and the leadership must be commissioned. Therefore, in order to acquire a naval ship, high risk management is necessary, and it is necessary to promote business success through effective application of system engineering which is a scientific management method. However, in the case of naval ships, there are no specific procedures and methods for applying the system engineering. Therefore, research on application method of system engineering which can be easily used by person in charge is necessary. This should have a simple approach to ensure effective business performance by systematically refining and simplifying existing works. QFD (Quality Function Deployment) is a way to improve product satisfaction, impress customers, reduce defective products, reduce design errors, and reduce costs. This systematically develops these mutual relationships by converting the needs of customers into quality characteristics of products and defining them as the design quality of products considering the functions, quality, and process elements of parts. The purpose of this research is to present concrete methodology at the practical level using QFD in a way to ensure traceability of requirements which is an important element of system engineering.