• 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 Computational Structural Engineering Institute of Korea
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• v.12 no.2
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• pp.243-249
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• 1999

지진력을 받는 건물의 응답을 능동적으로 제어하기 위해서는 건물의 응답을 측정하고, 이것을 바탕으로 제어력을 산정하여야 한다. 제어력의 산정 방법에는 여러 제어 알고리듬이 적용이 될 수 있는데, 2차 성능지수를 이용하는 LQ제어는 해석의 용이함과 제어의 효율성으로 인하여 널리 쓰이고 있다. 그러나, LQ제어에는 실시간으로 계측이 된 건물의 지반과의 상대 변위 및 속도를 필요로 하나 이러한 상태 변수를 계측하기가 매우 어려워 건물의 제어를 위한 적용에 한계가 있다. 따라서, 계측이 용이한 건물의 절대 가속도를 바탕으로 관측이 용이한 건물의 절대 가속도를 바탕으로 관측기를 이용하여 상태 변수를 추정하여 제어력을 산정하는 LQC 제어 알고리듬이 지진력을 받는 건물에 대한 실용적인 알고리듬이 될 수 있다. 본 연구에서는 이러한 LQC 알고리듬의 성능을 검증하기 위하여 능동제어추진기가 설치된 축소 1층 모형에 대한 해석 및 실험을 수행하였으며, 그 결과 LQC 알고리듬의 제어 효율을 확인할 수 있었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.984-990
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• 2017

The domestic cultural contents industry has been growing rapidly since the 2000s. The government has designated the cultural content industry as the next generation domestic growth industry. In order to cultivate this, various regulations are made and the budget is supported. Local governments are preparing various policies of cultural contents industry. This study presents the economic ripple effect by analyzing the status level and competence of the cultural contents industry in region based on LQ(location quotient) analysis and GAP analysis. Through this, this study will examine the competitiveness of the cultural content industry with high added value in Busan and draw out the plan for activation of cultural contents. Also, this study will compare competitiveness of Busan with other regions and show the economic contribution of Busan City.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.2
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• pp.73-85
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• 2016

Systematic and efficient forestry management is required because of the long-term low profitability of timber production and forest products. In this situation, non-timber forest products can be the solution to secure stable sources of income for workers in the forestry field. However, the existing studies for non-timber forest products focus on effective production and economic analysis and provide plans for increasing the income and improving the marketing system. Therefore, this research intends to analyze the spatial distribution as well as quantitative concentration of non-timber forest production. To achieve this goal, this study examined the regional concentration and dispersion of non-timber forest production in 2001, 2007, and 2014 using the coefficient of localization(CL) and location quotient(LQ) and investigated the change in spatial distribution using spatial statistics. The production of chestnuts generally showed a concentrated pattern in 2014 based on the outputs of the CL and LQ, but the result of spatial autocorrelation indicated a decrease in the spatial concentration. In addition, astringent persimmon showed more concentration from the output of CL than oak mushroom, but Moran's I suggests the opposite. Therefore, it is necessary to examine the spatial distribution to understand and improve the marketing system and intensify the production of forest products.

• Journal of the Korean Academic Society of Industrial Cluster
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• v.4 no.1
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• pp.14-50
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• 2010

This study focused on the competitiveness analysis of industrial cluster using econometric method and competency analysis method to measure the situation of Seocho-gu industrial cluster and Yangjae R&D cluster at Seoul. The econometric method used the data such as the number of firms, the number of employee, GRDP. The competency analysis method measured the level of agglomeration of cluster for years through LQ(Location quotient) index. In addition, the characteristics and structure of each industry in Secho-gu and Yangjae-dong R&D cluster. The circumstance of location and business, the competency of potential ability of industries were analysed by SWOT. In sum, this study has the following conclusion. First, Seocho-gu and Yangjae-dong region has an advantage in the circumstance for R&D related industry and man power. Second, Seocho-gu and Yangjae-dong region has a good potential for development in R&D related industries. These region has a good relationship the four major R&D related industry of Seoul. Third, these region also has a advantage in the potential development of R&D related researchers in the corresponding industries.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1581-1589
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• 2013

The aim of this study is to suggest a methodology for calculating the peak-hour ratio of passengers at urban railway stations by reflecting the characteristics of passenger demand patterns and the land use inventory of stations. To achieve this, urban railway stations in Seoul are divided into three groups by using factor analysis and cluster analysis. For each station group, we calculate five and four variables related to the passenger demand patterns and the land use inventory of stations, respectively, as well as the peak-hour ratios of passengers. Among these nine variables, average daily passengers and the location quotient (LQ) index for business services are selected as the classification criteria for station groups based on statistical tests. Using the two variables, a group allocation process is suggested to estimate the peak-hour ratio of passengers for a newly-constructed station. Evaluation results based on thirteen stations show that the proposed methodology produces lower errors than the currently-used guideline does. The results of this study contribute to establishing efficiently construction and operation plans for newly-constructed stations.

• Journal of Korea Port Economic Association
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• v.31 no.4
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• pp.75-89
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• 2015

This study examines 31 import and export cargo items handled in each port to investigate which items face the most competition among the ports and how many of them are transited to other ports. The study aims to suggest implications for the future port policy of Incheon Port. It was found that the volume concentration in the Western Coast region from 2005 to 2014 became increasingly decentralized. The decentralization began in earnest in 2009 in particular, and the value was 0.448 in 2014, indicating fierce competition among the regions. According to the static and dynamic positioning analyses results for Incheon Port, Pyeongtaek and Dangjin Port, and Gunsan Port, using BCG Matrix, the static positioning analysis showed that Incheon Port belongs to the 3rd quadrant (Cash Cows), Pyeongtaek and Dangjin Port belongs to the 2nd quadrant (Question Marks), and Gunsan Port belongs to the (Dogs) group. This implies that Incheon Port has maintained its position with large shares compared to those of other ports, despite its low growth rate. However, the market position and growth rate of Incheon Port decreased according to the dynamic positioning analysis results. The shift-share analysis results indicated that the volumes of Incheon Port and Gunsan Port were shifting to Pyeongtaek and Dangjin Port. Moreover, the ratio of absolute growth to potential growth of Incheon Port and Gunsan Port turned out to be significantly lower than that of Pyeongtaek and Dangjin Port, implying that Incheon Port and Gunsan Port are declining as compared to Pyeongtaek Port and Dangjin Port. According to the LQ index analysis results, specialized items from Incheon Port that do not overlap with other ports included the following ten items: meat, fish and crustaceans, bituminous coals, crude oil and petroleum, petroleum-refined products, plastic rubber and products, textiles, nonferrous metal and products, electric machinery, and aircrafts and ships. In particular, it was confirmed that the bulk cargo of Incheon Port was actually shifting to Pyeongtaek and Dangjin Port following the policy of re-establishing port functions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.620-626
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• 2021

The purpose of this study is to examine the characteristics and industrial structure and to present a future vision through analysis of industrial agglomeration, growth, and industrial efficiency targeting the Chungnam display industry nurtured by regional industrial policies since 2002. The industrial scale and aggregate status were analyzed through the business scale quotient and location quotient, and the growth and pace of structural change in the industry were analyzed through the industrial growth rate and change of industrial structure. Analysis results found the display industry shows its solid status based on industrial agglomeration. The RLQ, added value ratio, and employment coefficient have a relatively high comparative advantage. However, the growth rate has declined, and the pace of structural change has become lower. The regional competitiveness has been deteriorating. It is necessary to develop strategies to help the industry evolve into a convergence display industry to secure competitiveness by forming value chains. The regional industrial policy 'Regional Innovation Growth Plan' should be utilized to foster local industries that consider the regional characteristics and development directions and to promote the shared growth of related subsidiary industries through fostering specialized complexes for materials, parts, and equipment.

• Review of Culture and Economy
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• v.19 no.2
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• pp.171-193
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• 2016

China's advertising industry has rapidly increased owing to economic growth and big market size. This paper covers the localization and relative efficiency in the Chinese advertising industry. To analyze localization level and efficiency of advertising industry, this paper uses Location Quotient(LQ) and Data Envelopment Analysis (DEA) respectively. According to the results, the first finding shows that the higher regional development level have the relative efficiencies, the higher regional development level also have regional specialization degree. The second finding indicates that Chinese advertising industries are multipolalized region by region. The last finding reveals that advertising industry of middle and west regions has long term development potentiality owing to high specialization degree with low relative efficiencies.