• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.212-218
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• 2021

The Proportional Integral Derivative (PID) controller is the most popular industrial controller and more than 90% process industries use this controller. During the past 50 years, numerous good tuning methods have been proposed for Single Input Single Output Systems. However, design of PI/PID controllers for multivariable processes is a challenge for the researchers. A comparative study of three PID controllers design methods has been carried-out. These methods include the DS (Direct Synthesis) method, IMC (Internal model Control) method and ETF (Effective Transfer Function) method. MIMO PID controllers are designed for a number of 2×2, 3×3 and 4×4 process models with multiple delays. The performance of the three methods has been evaluated through simulation studies in Matlab/Simulink environment. After extensive simulation studies, it is found that the Effective Transfer Function (ETF) Method produces better output responses among two methods. In this work, only decentralized methods of PID controllers have been studied and investigated.

• International Journal of Computer Science & Network Security
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• v.21 no.9
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• pp.11-18
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• 2021

The Proportional Integral Derivative (PID) controller is the most popular industrial controller and more than 90% process industries use this controller. During the past 50 years, numerous good tuning methods have been proposed for Single Input Single Output Systems. However, design of PI/PID controllers for multivariable processes is a challenge for the researchers. A comparative study of three PID controllers design methods has been carried-out. These methods include the DS (Direct Synthesis) method, IMC (Internal model Control) method and ETF (Effective Transfer Function) method. MIMO PID controllers are designed for a number of 2×2, 3×3 and 4×4 process models with multiple delays. The performance of the three methods has been evaluated through simulation studies in Matlab/Simulink environment. After extensive simulation studies, it is found that the Effective Transfer Function (ETF) Method produces better output responses among two methods. In this work, only decentralized methods of PID controllers have been studied and investigated.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.488-488
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• 2000

This paper proposes a stabilizing controller for multirate sampled-data systems which have a periodic output The proposed controller has IMC structure, and can be decomposed into a ye-stabilizing controller, an output estimator, a filtered disturbance estimator and the inverse of the fast ye-stabilized plant model. We assume that the plant is open-loop unstable and the disturbance consists of a sum of finite number of sinusoids with different frequencies. A sufficient condition for maintaining observability in the multirate sampled-data system is derived and a design strategy for filtered disturbance rejection is proposed. In addition, we propose a design method (or the plant output estimator. The simulation results show that the proposed stabilizing controllers can stabilize the plant

• Journal of Power Electronics
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• v.9 no.1
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• pp.68-73
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• 2009

Automotive inverters may require current sensors for motor torque control, especially, in applications of hybrid electric vehicles or fuel cell vehicles. In this paper, to achieve a compact, integrated and low cost current sensor, a hall current sensor without magnetic core is introduced for integrating an automotive inverter. The compactness of the current sensor is possible by using integrated magnetic concentrators based on the Hall effect. Magnetic fields caused by three-phase currents are analyzed and a magnetic shield design is proposed for decoupling the cross-coupled field. It offers galvanic isolation, wide bandwidth (>100kHz), and accuracy(< 1%). Using 2D FEM analysis, its performance is demonstrated with design parameters at a U-shaped magnetic shield. The proposed coreless current sensor is tested with rated current to validate the linearity and accuracy.

• Resources Recycling
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• v.22 no.2
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• pp.62-70
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• 2013

Electric arc furnace slag is made in ironworks during steel refining, it is been increasing chemical and physical resistibility using ageing method of unstable state of melting steel slag for using concrete's fine aggregates. Which is been changing stable molecular structure of aggregates, it restrains moving of ion and molecule. In Korea, KS F 4571 has been prepared for using the electric arc furnace slag to concrete aggregates. In this study, Electric arc furnace slag is used in the PMC(Polymer Modified Concrete) which is applied a bridge pavement of rehabilitation, largely. In that case, this study evaluates the structural safety about increasing the specific weight. The 4-type bridges(RC slab bridge, RC rigid-frame bridge, PSC Beam bridge, Steel box girder bridge) pavement's increasing the total dead load is in 1 ~ 2%. Design moments in a load combination are increased less then 2%. safety factor is decreased less than 3%. Therefore, the structural safety has no problem for applying the electric arc furnace slag within PMC in bridge.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.2
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• pp.41-47
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• 2010

The effect of PCB and BGA pad designs was investigated on the mechanical property of Pb-free solder joints. The mechanical property of solder joint was tested by three different test methods of drop impact tests, bending impact test, and high speed shear test. Two kinds of pad design such as NSMD (Non-Solder Mask Defined) and SMD (Solder Mask Defined) were applied with the OSP finished Pb-free solder (Sn-3.0Ag-0.5Cu, Sn-1.2Ag-0.5Cu). in the drop impact test and bending impact test, the characterized lifetime showed the same tendency, and SMD design showed better mechanical property of solder joint than NSMD regardless of test method, which was due to the different crack path. The fracture crack on SMD pad was propagated along the intermetallic compound (IMC) layer of solder joint, while the fracture crack on NSMD pad propagated through upper edge of land which shields pattern. In the high speed shear test, pad lift occurred on the solder joint of NSMD. SMD/SMD combination of pad design consequently illustrated the best mechanical property of BGA/PCB solder joint, followed by SMD/NSMD, NSMD/SMD, and NSMD/NSMD.

• International Commerce and Information Review
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• v.3 no.1
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• pp.157-176
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• 2001

국내외 마케팅에 있어서 경쟁의 심화로 말미암아 새로운 고객의 획득에 따른 비용-효과보다 기존고객과의 관계유지를 위하여 고객의 평생가치를 높이도록 노력하는 것이 오히려 효과적인 경우가 많아졌다. 이러한 관계마케팅의 개념은 최근 마케팅을 포함한 기업경영 전반에 적용되는 고객관계관리(CRM)로 확장되고 있다. 또한 인터넷 기반의 e CRM이 고객행동의 분석도구를 거의 정확하고도 실시간으로 파악할 수 있게 함으로써 통합적 CRM의 아키텍쳐와 솔루션이 개발, 적용되고 있다. 통합 CRM에서의 고객은 B2B이든 B2C이든 간에 개별(개인) 고객을 가리키며, 개별 고객의 니즈와 요구를 적절하게 충족시킬 수 있도록 개인화 시스템을 구축하여 관리하는 것이 중요하다. 따라서 본 논문에서는 통합 CRM의 기본 틀과 시스템을 비롯하여 개인화 설계를 어떻게 할 것인가에 관한 사례 및 실증분석에 앞서 그 배경 지식을 정리하고자 이론적 탐구를 하였다.

• Journal of information and communication convergence engineering
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• v.2 no.1
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• pp.46-51
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• 2004

The problem of reducing the effect of an unknown disturbance on a dynamical system is one of the most fundamental issues in control design. We propose a robust PID (Proportional Integral Derivative) control method with neural network for improving the performance due to the rejection of an unknown disturbance. The proposed system consists of a model of the plant, a conventional PID controller and a multi-layer neural network, and is composed of two loop; the first loop enables the system to achieve stability of system, the second loop rejects an unknown disturbance. Simulation and experiment results show that the proposed method improves considerably on the performance of the conventional PID control method and the typical IMC method using neural network.

• Journal of the Korea Fashion and Costume Design Association
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• v.25 no.2
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• pp.17-29
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• 2023

The digital environment, which has been rapidly developing since the beginning of the 21^st century, has become more specific due to COVID-19, and marketing strategies are rapidly changing to suit purchasing activities of Generation MZ, whose online purchases are becoming the center of their lives. A public relations agency is generally responsible for all aspects of making a client's product or service visible to the public through various forms of media. Among them, a company that performs only fashion-related tasks is called a "fashion PR agency". Now, the fashion industry is also centered on the e-commerce environment, and various digital marketing strategies have been developed and directly related to sales. This study examined the current status of online media and digital marketing, analyzes the aspects of fashion brand promotion strategies and methods in the e-commerce era, focusing on the work of fashion PR agencies, and suggests the direction of new online and offline promotion methods based on marketing and technological aspects. As a result of the study, first, theories on strategies for online media and digital marketing were examined, and found that the amount of online promotion has recently increased and become more specialized. Second, this study examines the concept of fashion PR agencies and analyzed their main tasks through interviews with fashion PR professionals. Third, based on successful online fashion promotion cases, the study analyzed fashion promotion strategies and methods that are being integrated online and offline in the e-commerce era. The main methods included SNS strategy, content strategy, performance strategy, influencer strategy, and event strategy, and it is suggested that integrated management is necessary for consistent brand image management, and an IMC (Integrated Marketing Communication) strategy, which intensively manages all strategies, should be employed.

• Geomechanics and Engineering
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• v.33 no.3
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• pp.301-315
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• 2023

Adopting cohesive soil as geocell-pocket infill materials is not fully accepted by researchers in the field of road engineering. The cohesion that may inhibit the lateral limitation of geocells is a common vital idea that exists within every researcher. However, the influence of infill materials' cohesion on geocell-reinforced performance is still not thoroughly determined. The mechanism behind this still needs to be studied in depth. This study initially discussed the relationship between subgrade bearing capacity, geocells' contribution to reinforced performance, and infill materials' cohesion (IMC). A law was proposed that adopting the soil with high cohesion as infill materials benefited the subgrade bearing capacity, but this was attributed to the superior mechanical properties of infill materials rather than geocells' contribution. Moreover, the vertical and lateral deformation of subgrade, coupling shear stress and confining stress of geocells, and deformation of geocells were deeply studied to analyze the mechanism that high cohesion can inhibit the geocells' contribution. The results indicate that the infill materials with high cohesion result in the total displacement of the subgrade toward to deeper depth, not the lateral direction. These responses decrease the vertical coupling shear stress, confining stress, and normal displacement of geocell walls, which weaken the lateral limitation of geocells.