• Journal of the Korean Society of Systems Engineering
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• v.15 no.2
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• pp.9-16
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• 2019

The most important task in acquiring the weapon system is to determine the required performance and to test & evaluate it. The importance of the weapon system by ROC (Required Operational Capability) is not considered, and system development and test evaluation are carried out. In addition, technical incidental performance is tested on the same basis as ROC in the test evaluation and determined according to the result. Development test and evaluation that evaluates technical ability is very important, but development agency is supervised and performed. In this paper, we propose a method to give weights considering the importance of ROC, a technical incidental performance determination and test procedure, and a improvement plan for the development and operational test & evaluation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.374-382
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• 2018

This paper has done a hardware-based approach to increase the modulation index in 3-phase inverters, unlike the conventional software algorithm-based approaches. The minimum required time to measure the currents in a three-phase inverters with shunt resistors has also been analyzed. By the analysis, the longest time in minimum required time is AD conversion time. To shorten the minimum required time, this paper proposed a sample-and-hold(S/H) circuit implemented at the inverter current signal output to retain the current signal. When the linear operation region of an inverter with S/H was compared with that without it, the modulation index was increased by 7.8 %. Inverters with S/H circuits can employ the traditional software algorithms, such as the voltage injection method or current restoration method, and it will yield further increase the modulation index.

• Earthquakes and Structures
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• v.12 no.3
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• pp.309-319
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• 2017

A new method is suggested for the retrofitting of torsionally sensitive buildings. The main objective is to eliminate the torsional component from the first two natural modes of the structure by properly modifying its stiffness distribution via selective strengthening of its vertical elements. Due to the multi-parameter nature of this problem, state-of-art optimization schemes together with an ad-hoc software implementation were used for quantifying the required stiffness increase, determine the required retrofitting scheme and finally design and analyze the required composite sections for structural rehabilitation. The performance of the suggested method and its positive impact on the earthquake response of such structures is demonstrated through benchmark examples and applications on actual torsionally sensitive buildings.

• Journal of Computational Design and Engineering
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• v.3 no.3
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• pp.274-285
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• 2016

A designer is mainly supported by two essential factors in design decisions. These two factors are intelligence and experience aiding the designer by predicting the interconnection between the required design parameters. Through classification of product data and similarity recognition between new and existing designs, it is partially possible to replace the required experience for an inexperienced designer. Given this context, the current paper addresses a framework for recognition and flexible retrieval of similar models in product design. The idea is to establish an infrastructure for transferring design as well as the required PLM (Product Lifecycle Management) know-how to the design phase of product development in order to reduce the design time. Furthermore, such a method can be applied as a brainstorming method for a new and creative product development as well. The proposed framework has been tested and benchmarked while showing promising results.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.15-218
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• 1999

Concrete is the most generous, universal main structural material. There is active study for processing quality, stable quality mangement. Especially, strength is basic factor of evaluating stability of concrete building. Regaining required strength and homogeneity is very important to get self-stability in building to evaluate another characteristic. Concrete strength is important to the quality management. But, result of hardened concrete's quality test is hardly reflected to works immediately. When required strength is not enough, it could bring out safe problem, economic and administrative cost. It is pointed out that problems from strength evaluation, so early evaluation of concrete quality is required. From the trend that accelerating high quality concrete development, improving the method of quality test and early evaluation measure is urgent project. Throughout this report, it is suggested the method with use of microwave to evaluate 28-days concrete strength.

• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.232-239
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• 1995

This study was carried out to get required torque data needed to design and develop a roll-up ventilation system in a pipe-constructed plastic film green-house. The results obtained from this study are as follows : 1. The required torques of a roll-up ventilation system in greenhouse are the functions of its length. The torques should multiplied by the conversion coefficients (2.0 in ceiling vent, 1.8 in side vent) in case of application. 2. In constructing pipe-constructed plastic film greenhouse, a shaft pipe is the largest essential element in roll - up shaft weight constitution which have an effect on the required torques. Therefore, the pipe should be light using nonferrous materials like aluminum alloy. 3. A planetary reduction ventilator of differential ring gear type is suitable for a roll-up ventilation system, because it can make high efficient reduction just using the first step shift.

• The Journal of Society for e-Business Studies
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• v.9 no.1
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• pp.209-220
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• 2004

If protocol has fast operations and short key length, it can be efficient user authentication protocol. Lenstra and Verheul proposed XTR. XTR have short key length and fast computing speed. Therefore, this can be used usefully in complex arithmetic. In this paper, to design efficient user authentication protocol we used a subgroup of Galois Field to problem domain. Proposed protocol does not use GF(p/sup 6/) that is existent finite field, and uses GF(p²) that is subgroup and solves problem. XTR-ElGamal based user authentication protocol reduced bit number that is required when exchange key by doing with upside. Also, proposed protocol provided easy calculation and execution by reducing required overhead when calculate. In this paper, we designed authentication protocol with y/sub i/ = g/sup b.p/sup 2(i-1)//ㆍv mol q, 1(equation omitted) 3 that is required to do user authentication.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.299-301
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• 2008

For an efficient operation of today's power system, power engineers are required to analyze enormous amount of data. Owing to the development of technology, a variety of power systems computational tools have been developed and commercialized. However, the practical use of computational tools not only requires that people be able to understand the results the tools produce but also extract the required information from the simulation results which generally involves massive amount of information. This paper introduces a novel interface that would complement the drawbacks in the visualization of data of the pre-existing tools and assist the user in readily retrieving the required information, in this case the rotor angle data, of the simulated system thereby making power system analysis more feasible to be effectuated.

• Journal of Korean Institute of Industrial Engineers
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• v.17 no.1
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• pp.109-115
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• 1991

In automated manufacturing systems, Automated Guided Vehicle(AGV) Systems are increasingly important in material handling and manufacturing operations. A considerably flexible AGV system needs to be operated with maximum effectiveness. This paper develops an algorithm for the determination of the entering point and the number of AGVs required in the Flow Shop Type FMS. We consider an AGV used as a carrier and mobile workstation. For the limited number of AGV, the entering point of an AGV on a simple loop is determined in order to maximize the utilization of AGVs. For the unlimited number of AGVs, the number of AGVs required in the FMS is determined on the basis of the entering point of AGVs. The result by the algorithm may be used as a criterion on the control of material flow and the assignment of AGVs in the FMS. A numerical example is given to illustrate the algorithm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.10
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• pp.1023-1028
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• 2009

Cleaning is required following CMP (chemical mechanical planarization) to remove particles. The minimization of particle residue is required with each successive technology generation, and the cleaning of wafers becomes more complicated. In copper damascene process for interconnection structure, it utilizes 2-step CMP consists of Cu and barrier CMP. Such a 2-steps CMP process leaves a lot of abrasive particles on the wafer surface, cleaning is required to remove abrasive particles. In this study, the chemical mechanical cleaning(CMC) is performed various conditions as a cleaning process. The CMC process combined mechanical cleaning by friction between a wafer and a pad and chemical cleaning by CMC solution consists of tetramethyl ammonium hydroxide (TMAH) / benzotriazole (BTA). This paper studies the removal of abrasive on the Cu wafer and the cleaning efficiency of CMC process.