• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2001.10a
• /
• pp.101-108
• /
• 2001

In the previous study, an improved QRD (QR Decomposition)-ILS(Iterative Least-Squares) method is proposed to estimate the structural parameters at the element level using response data alone without using any information of excitation measurements for the assessment of local damages and deterioration in complex and large structural systems. But for a complex and large structural system, where response measurement at every dynamic degree of freedom(DDOF) is not possible, the absence of some observation points of responses and its effect on the proposed SI method must be studied In the paper, a QRD-ILS technique that utilizes the known intact stiffness information estimated based on the visual inspection, field measurements and/or NDT tests is proposed to identify local damages of fracture critical members using measured responses only at limited DDOFs. A numerical example is used to illustrate the application of this technique. The results indicate that the proposed SI technique is very simple but efficient, since no input information are required with only limited observations.

• KSBB Journal
• /
• v.18 no.5
• /
• pp.356-362
• /
• 2003

This study defines the biotechnology industry, examines its position in the domestic economy, and analyses its structure with I-O tables of year 1985, 1990 and 1995. Structural decomposition analysis is used in order to estimate the impact of different sources of growth. We classifies Korean biotechnology industry into 6 sectors, based on the survey of domestic biotechnology industry by Bioindustry Association of Korea. Empirical results indicate that each sector of bioindustry has various sources of growth and industrial demand has led the growth in all sectors except for food-bio and agriculture-bio. For the growth of the industry, each sector needs to cope with the change of the private demand and to improve the import and export structure.

• Structural Engineering and Mechanics
• /
• v.61 no.2
• /
• pp.267-274
• /
• 2017

In this study was investigated of possibility using the recorded micro tremor data on ground level as ambient vibration input excitation data for investigation and application Operational Modal Analysis (OMA) on the bench-scale earthquake simulator (The Quanser Shake Table) for model steel structures. As known OMA methods (such as EFDD, SSI and so on) are supposed to deal with the ambient responses. For this purpose, analytical and experimental modal analysis of a model steel structure for dynamic characteristics was evaluated. 3D Finite element model of the building was evaluated for the model steel structure based on the design drawing. Ambient excitation was provided by shake table from the recorded micro tremor ambient vibration data on ground level. Enhanced Frequency Domain Decomposition is used for the output only modal identification. From this study, best correlation is found between mode shapes. Natural frequencies and analytical frequencies in average (only) 2.8% are differences.

• The Journal of the Korea Contents Association
• /
• v.17 no.10
• /
• pp.598-615
• /
• 2017

This paper compares the sources of the changes in the production of manufacturing industry between Korea and Japan during year 2000 ~year 2011 by I-O SDA. The results show that the first source of the increase in the production of Manufacturing industry in Korea is export, while in Japan the technological change. However, the contribution of technological change is relatively small in Korea and moreover decreasing. Meanwhile, the domestic final demand is the second source of the increase in the production of Korean manufacturing industry, but it was the first source of the decrease in the production of Japanese counterpart. On the other hand, the decrease in import substitution for both the intermediate and domestic final goods is significantly contributed to the decrease in the production of both Korean and Japanese manufacturing industry. Conclusively, these results confirm that the growth of Korean manufacturing industry has heavily depended on export. Then, considering the current global economic environment that is rapidly becoming more uncertain as well as volatile, the results imply that the heavy export dependence may become a key hurdle for the solid sustained growth of Korean manufacturing industry, so that policy ensuring more evenly balanced growth contribution from all growth sources is necessary. In particular, policy to promote technological change and import substitution is required with greater weight.

• Journal of the Economic Geographical Society of Korea
• /
• v.20 no.1
• /
• pp.1-15
• /
• 2017

This paper analyzes empirically how the three main industries (petrochemical industry, shipbuilding industry, automobile industry) that are driving the growth of Ulsan region in 2005~2013 have grown by what factors. For this purpose, we investigate the structural changes of the three main industries by using regional input-output tables announced by the Bank of Korea and examine the growth contribution rate of each industry that is divided into domestic final demand, export demand, import substitution for final goods, import substitution for intermediate goods and technological change, respectively. The growth rate of gross output and aggregate demand in petrochemical and automobile industries increased in 2010-1013 compared to 2005-2010, but the growth rate of gross output and aggregate demand in shipbuilding industry slowed down. As a result of analysis of factors contributing to the increase in gross output of the three main industries, export demand has the greatest effect. By industry, the rate of growth contribution of export demand in petrochemical industry is recorded as 209.23% in 2005-2010 and 113.78% in 2010-2013, respectively. The rate of growth contribution of export demand in automobile industry is recorded as 258.72% in 2005-2010 and 72.69% in 2010-2013, respectively. On the other hand, the rate of growth contribution of export demand in shipbuilding industry is recorded as 94.47% in 2005-2010, but it decreased to -255.32% in 2010-2013. Analysis of growth factors of Ulsan's three main industries is expected to serve as the basis for reorganizing related industrial policies and establishing them.

• Environmental and Resource Economics Review
• /
• v.14 no.2
• /
• pp.257-290
• /
• 2005

Korean energy use in industrial sector has increased more rapidly than other sectors during 1980~2000 periods. Relatively higher increases in industrial sector energy consumption raise questions whether government policy of rationalization of industrial energy use has been effective. In this study, we use 80-85-90 and 90-95-00 constant price input-output table to analyze increases in industrial energy use. Using an adjusted version of structural decomposition model introduced by Chen and Rose (1990), we decompose Changes of energy use into 17 elements. We classify entire industry sector into 32 sectors including four energy sectors (coal and coal products, refined petroleum, electricity and town gas). We then analyze changes of energy use by industrial level to check differences among industrial energy demand structures. Finally, we compare three industries, electronic product manufacturing, metal manufacturing and construction, that represent technology and capital intensive, energy and material intensive and labor and capital intensive industry. As results, we find that high energy using industries make the most effort to reduce energy use. Primary metal, petrochemical and mon-metal industries show improvements in elements such as energy and material productivity, energy and material imports, energy substitution and material substitutions towards energy saving. These results imply that although those industries are heavy users of energy, they put the best effort to reduce energy use relative to other industries. We find various patterns of change in industrial energy use at industrial level. To reduce energy use, electronic product manufacturing industry needs more effort to improve technological change element while construction industry needs more effort to improve material input structure element.

• KDI Journal of Economic Policy
• /
• v.12 no.1
• /
• pp.3-29
• /
• 1990

Korean input-output tables for 1975 and 1985 are first deflated into 1975 constant domestic prices(hypothetical terms), and the constant price I-O data are used to decompose the sources of industrial growth and structural change during the 1975-85 period. Using the same methodology, our results for the 1975-85 period are then linked to the results for the earlier period(1955-75) in order to analyze and evaluate the "demand-side" sources of industrialization over the past three decades. The results from the decomposition of the whole economy indicate that over three decades(1955-85) the relative contribution of domestic demand expansion (DDE) to growth and structural change has continuously declined while the contribution of export expansion(EE) has generally continued to rise. The contribution of import-substitution(IS) which had been significantly higher than that of EE during 1955-63 declined substantially, remaining at an insignificantly low level during the period following 1963. Although it is well known that the government's industrial policy in the 1970s emphasized import-substitution in heavy and chemical industries, no significant changes in the export-oriented growth pattern could be observed even for that period, except for a minor decline in the relative contribution of EE. This may be attributed to the substantially larger, backward-linkage effects of EE than that of IS. The sources-of-growth decompositions for major branches of the manufacturing sector generally support the major conclusions derived from the decomposition for the whole economy. The IS contribution which had been significantly high in almost all manufacturing branches during the 1955-63 period declined to low levels in all but two branches, heavy industry and machinery, during the following period. On the other hand, the relative contribution of EE showed a continuous rise in almost all manufacturing branches(except food processing). Finally, the sources of growth for 1975-85 which were decomposed by detailed sub branches, are analyzed by correlating them with changes in relative prices and industrial protection rates by sub-branches for the same period. A major result is that contrary to general expectations, the EE contributions by sub-branch are not negatively correlated with the nominal rates of protection and/or the effective rates of protection for the same sub-branches. It is also found that no statistically significant, positive correlation exists between IS contributions and nominal protection rates or effective protection rates. These unexpected results may be explained by the peculiar nature of the Korean system of industrial incentives for the past period.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.26 no.2
• /
• pp.99-112
• /
• 2013

This paper presents a subspace system identification for estimating the stiffness matrix and flexural rigidities of a shear building. System matrices are estimated by LQ decomposition and singular value decomposition from an input-output Hankel matrix. The estimated system matrices are converted into a real coordinate through similarity transformation, and the stiffness matrix is estimated from the system matrices. The accuracy and the stability of an estimated stiffness matrix depend on the size of the associated Hankel matrix. The estimation error curve of the stiffness matrix is obtained with respect to the size of a Hankel matrix using a prior finite element model of a shear building. The sizes of the Hankel matrix, which are consistent with a target accuracy level, are chosen through this curve. Among these candidate sizes of the Hankel matrix, more proper one can be determined considering the computational cost of subspace identification. The stiffness matrix and flexural rigidities are estimated using the Hankel matrix with the candidate sizes. The validity of the proposed method is demonstrated through the numerical example of a five-story shear building model with and without damage.