• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.3
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• pp.9-16
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• 1996

LQ-servo is a robustness guaranteed multivariable controller design method based on the LQR structure to improve command following with output feedback. in this paper we introduce a weighting factor on the low frequency part of the state weighting matrix in the performance index in order to increase the low frequency gain of loop transfer function matrix T(s) in the loop shaping design method.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.3
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• pp.120-129
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• 2001

A two-degree-of-freedom quarter-car model is used as the basis for LQ and the proposed controller design for a semi-active suspension. The LQ controller results in the best rms performance trade-offs(as defined by performance index) between ride, handling and packaging requirements. In LQ controller, however, the conflict between road holding and ride comfort remains. The adaptive semi-active suspension control based on the road frequency are introduced in this paper. With this method, the trade-off between road holding and ride comfort can be relaxed. The road frequency is estimated by wavelet transform if rattle space signal. The simulation results show that the proposed controller is superior to the conventional LQ controller.

• Journal of Digital Convergence
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• v.9 no.3
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• pp.133-144
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• 2011

The purpose of this study are as follows. First, to analyze relative LQ index of the No. of game company, the No. of employee and the amount of revenue. Second, to analyze personal competence, resource competence, performance competence, network competence and environmental competence of regional game contents R&D. The results are as follows. The LQ index results of company are highest in seoul and Kyunggi area' And In case of except of seoul & kyunggi, the competence of R&D which is daekyung, dongnam, chungcheong are in order. In case of 5 game R&D competence, chungchung, seoul & kyunggi, honam region are in order. The core competence of chungchung region are ideal venture ecosystem among inter-supportive R&D research center, ETRI, university and company.

• Journal of Korea Technology Innovation Society
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• v.16 no.4
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• pp.1187-1204
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• 2013

The purpose of this study is to analyze the industry infra competence status between game and character industry and to investigate relational industry cluster by LQ index. Applying to relative LQ index was no. of company, the no. of employee and the amount of revenue of 2012 years between game industry and character industry. The regional cluster block composed of metropolitan block (Seoul, incheon & Kyunggi area) and regional blocks(kangwon, chungchung, daekung, honam, dongnam and jeju region). The results of this research are as follows. First, the competency level of the quantity estimation of game industry and character industry highly concentrated to Seoul, Incheon & Kyunggi block. In case of the inter industrial competency analysis including metropolitan block, the high competency level indicated among metropolitan block, kangwon, dongnam and jeju region. In case of except metropolitan, dongnam and jeju region indicated high OSMU possibility between two industry. The contribution of this research was assessment of regional game and character culture contents' industry competences. And this research suggested fact based quantitative analysis of OSMU accessibility and validity of game and character industry's competence.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.2
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• pp.75-83
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• 2019

Using geographical indication, a type of source identification, can effectively promote local specialty agricultural products of superior quality, by identifying the specific geographic location or origin of the produce. Agricultural products can be registered using the geographical indication by describing the product's relation to its geographical origin including the reputation and quality. However, this indication has no objective standards to qualify goods as agricultural specialty products. The purpose of this study is to suggest basic criteria to define the characteristics and criteria of agricultural specialties based on a quantitative evaluation method. To propose this basic standard, we used the proportion of arable land to denote the major production areas and the location quotient (LQ) index to grasp the extent of the specialty of a product. The results show that the average LQ values of registered agricultural products, particularly apples, pears, and garlic, are 3.26, 8.01, and 2.82, respectively. This indicates that they are more specialized than produce from other areas that have not registered for a geographical indication. Low LQ values were found in some areas with registered rice geographical indications, which are also more focused on their historical reputation as the main rice producing areas. Considering the agricultural specialty of products, the recommendation is that the producing proportion should be over 1% of the national scale and over 10% of the province scale, and the LQ value should be over 2.0. This recommendation is not a requirement, but the criteria can prove to be useful in identifying a higher range of specialized agricultural products.

• The Korean Journal of Applied Statistics
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• v.21 no.4
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• pp.581-588
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• 2008

The purpose of this study is to introduce a relative specialization index, the Nam-Oh-Hong Index(NOHI) and to investigate regional distribution of occupational specialization using the newly developed index. Compared with Location Quotient(LQ), the advantages of the index is that the NOHI enables comparison between inter-regional and intra-regional concentration of employment possible at the same time. The results of the specialization analyses show that Seoul is specialized in management, book-keeping and office related occupations, whereas Busan in machine and material related occupations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.608-616
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• 2018

If a general nonlinear system is linearized by the successive multiplication of the 1st and 2nd order systems, then there are four types of poles in this linearized system: the pole of the 1st order system and the equal poles, two distinct real poles, and complex conjugate pair of poles of the 2nd order system. Linear Quadratic (LQ) control is a method of designing a control law that minimizes the quadratic performance index. It has the advantage of ensuring the stability of the system and the pole placement of the root of the system by weighted matrix adjustment. LQ control by the weighted matrix can move the position of the pole of the system arbitrarily, but it is difficult to set the weighting matrix by the trial and error method. This problem can be solved using the characteristic equations of the Hamiltonian system, and if the control weighting matrix is a symmetric matrix of constants, it is possible to move several poles of the system to the desired closed loop poles by applying the control law repeatedly. The paper presents a method of calculating the state weighting matrix and the control law for moving the equal poles with Jordan blocks to two real poles using the characteristic equation of the Hamiltonian system. We express this characteristic equation with a state weighting matrix by means of a trigonometric function, and we derive the relation function (${\rho},\;{\theta}$) between the equal poles and the state weighting matrix under the condition that the two real poles are the roots of the characteristic equation. Then, we obtain the moving-range of the two real poles under the condition that the state weighting matrix becomes a positive semi-finite matrix. We calculate the state weighting matrix and the control law by substituting the two real roots selected in the moving-range into the relational function. As an example, we apply the proposed method to a simple example 3rd order system.

• Journal of the Korean Regional Science Association
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• v.32 no.3
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• pp.17-27
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• 2016

In order to solve the problem of how to estimate the residential segregation, the Spatial Concentration Index(SCI) and Location quotient(LQ) are able to be one of alternative methods, and a comprehensive analysis of the residential segregation phenomenon in the seoul metropolitan area is the aim of the study. The results of SCI show that residential concentration areas in low-rent are some Gyeonggi-do's downtown(Bucheon-si, Suwon-si) as well as rural and urban-rural complex outskirts of the metropolitan area. The results of changing of SCI from 2011 to 2014, downward changes appeared thirteen districts and upward changes appeared fourteen districts. Especially downward change district was Sosa-gu, Bucheon-si and upward change district was Yeongtong-gu, Suwon-si. In conclusion, that high rent level groups are more concentration on specific area than low rent level groups. By decreasing residential concentration districts in low-rent level group, 'diversity' districts have been increasing in seoul metropolitan but the phenomenon of residential concentration in high and low level group have been being intensified. These results could be confirmed by quantitative through LQ. Methodologically LQ would strengthen the explanatory power of SCI, and ongoing research of SCI in conjunction with other quantitative methods will need.

• Journal of Industrial Technology
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• v.10
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• pp.3-8
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• 1990

This paper presents a linear state feedback control approach to the stabilization of discrete-time uncertain systems with bounded uncertain parameters. The approach is based on the LQ(linear quadratic) regulator theory and Lyapunov's stability analysis. Asymptotically stable behavior is guaranteed in the presence of parameter uncertainties, and the upper bound of the performance index is determined.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.10
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• pp.856-860
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• 2002

The guaranteed stability margin of LQ optimal regulators with cross-product terms in a performance index is derived for the discrete-time case. In order to obtain the guaranteed stability margin, the singular value of the return difference matrix is examined. A numerical simulation is provided to demonstrate the validity of the derived stability margin.