Effects of U.S. Macroeconomic Shocks on International Commodity Prices

Won Joong Kim,Shawkat Hammoudeh,Kyongwook Choi 한국경제연구학회 2014 Korea and the World Economy Vol.15 No.1

Using a structural VAR with block exogeneity, diagonality and identifying restrictions, the paper first analyzes the macroeconomic linkages among the oil price, U.S. output, interest rate, money supply, price level, and exchange rate, and second with international non-fuel commodity group prices. By assuming the block exogeneity of U.S. macroeconomic variables with respect to the international non-fuel commodity prices, the paper discusses how exogenous macroeconomic shocks affect those commodity prices. It finally explores which oil/macroeconomic shocks are important in explaining the variations in the commodity prices. The results show that the sources of major fluctuations in the international commodity differ greatly by commodity. Some commodity prices seem to be affected greatly by financial factor such as ‘seafood’, ‘industrial metal’, and ‘gold’. Moreover, for some commodities, price volatilities are more affected by financial factor than by real factor. Those commodities include ‘vegetable oils and protein meals’, ‘meat’, ‘seafood’, and ‘industrial metals’. Financial factor is also important source of fluctuations in the oil prices. Oil price shocks have instantaneous effects on the volatilities of interest rates, money supply, and price level. Oil shocks also have significant effects on interest rate, money supply, and exchange rate two years after the shock.

Effects of U.S. Macroeconomic Shocks on International Commodity Prices

김원중,하무데,최경욱 한국경제연구학회 2014 Korea and the World Economy Vol.15 No.1

Using a structural VAR with block exogeneity, diagonality and identifying restrictions, the paper first analyzes the macroeconomic linkages among the oil price, U.S. output, interest rate, money supply, price level, and exchange rate, and second with international non-fuel commodity group prices. By assuming the block exogeneity of U.S. macroeconomic variables with respect to the international non-fuel commodity prices, the paper discusses how exogenous macroeconomic shocks affect those commodity prices. It finally explores which oil/macroeconomic shocks are important in explaining the variations in the commodity prices. The results show that the sources of major fluctuations in the international commodity differ greatly by commodity. Some commodity prices seem to be affected greatly by financial factor such as ‘seafood’, ‘industrial metal’, and ‘gold’. Moreover, for some commodities, price volatilities are more affected by financial factor than by real factor. Those commodities include ‘vegetable oils and protein meals’, ‘meat’, ‘seafood’, and ‘industrial metals’. Financial factor is also important source of fluctuations in the oil prices. Oil price shocks have instantaneous effects on the volatilities of interest rates, money supply, and price level. Oil shocks also have significant effects on interest rate, money supply, and exchange rate two years after the shock.

Effects of U.S. Macroeconomic Shocks on International Commodity Prices: Emphasis on Price and Exchange Rate Pass-through Effects

( Won Joong Kim ),( Shawkat Hammoudeh ),( Kyongwook Choi ) 한국환경경제학회·한국자원경제학회(구 한국환경경제학회) 2012 한국환경경제학회 학술발표논문집 Vol.2012 No.경제학 공동

Using a structural VAR with block exogeneity, diagonality and identifying restrictions, this paper analyzes: first, the macroeconomic linkages among the oil price, U.S. output, interest rate, money supply, general price level and exchange rate; and second, the relationships of the macroeconomic variables with the price indices of ten international nonfuel commodity groups. By assuming the block exogeneity of U.S. macroeconomic variables with respect to the international nonfuel commodity prices, the paper discusses how exogenous oil/macroeconomic shocks affect the international commodity prices. It finally explores which oil/macroeconomic shocks are important in explaining the variations in international commodity prices. The results show that the sources of major fluctuations in the international commodities differ greatly by commodity. Soft and hard commodity prices such as those of ‘seafood’, ‘industrial metals’, and ‘gold’ seem to be strongly affected by the financial factor. Moreover, for some commodities, price fluctuations are more affected by the financial factor than by the real factor, supporting the view of “financialization” of commodities. Those commodities include ‘vegetable oils and protein meals’, ‘meat’, ‘seafood’, and ‘industrial metals’. The financial factor is also an important source of fluctuations in the oil prices. Oil price shocks have effects on the volatilities of interest rates, money supply, and general price level instantly, as well as on the exchange rate instead of the general price two years after the shock. Over the whole forecasting horizon, the degree of exchange rate pass-through is low on the general price level but is positive and high on oil and nonfuel international commodity prices.

ICT 산업의 국민경제 및 타 산업 파급효과 분석

현준석(Jun Seog Hyun),김원중(Won Joong Kim) 한국경제연구학회 2015 한국경제연구 Vol.33 No.1

ICT 산업은 중간재, 자본재 혹은 업무 프로세스 개선 등의 다양한 용도로 타산업의 생산에 영향을 미칠 수 있다. 따라서 본 연구에서는 블록 외생성(block exogeneity) 및 독립성(diagonality)을 가정한 구조적 벡터자기회귀모형(SVAR)을 이용하여 ICT 산업이 국민경제 및 타 산업에 미치는 영향을 실증적으로 분석하였다. 1997년 1월부터 2013년 8월까지의 월별 자료를 이용하여 분석한 결과, ICT 생산충격은 산업생산 및 수출 등의 국민경제에 긍정적인 영향을 미치는 것으로 나타났다. 크기의 차이는 있으나 ICT 생산충격은 전반적으로 개별 제조업 생산에도 통계적으로 유의하게 긍정적인 영향을 미치는 것으로 나타났다. 한편 분산 분해 분석결과 ICT 생산충격은 ICT 밀접산업뿐만 아니라 일반 전통산업의 생산 변동성에도 통계적으로 유의하게 영향을 미치는 것으로 나타났다. Using a structural vector autoregression model with block exogeneity and diagonality assumptions, this study identifies exogenous ICT productivity shocks and estimates the effects of those shocks both on the national income and on other manufacturing industries. The results show that ICT shock has positive effects on national income as well as on the productions in most of manufacturing industries. The variance decomposition results reveal that ICT shock explains with statistical significance the volatilities in the productions of ‘medical/precision product’, ‘other machinery’. ‘rubber and plastic product’. ‘basic metal product’ and ‘fabricated metal product.’ The results confirm that ICT has important impacts on other industries either as intermediate goods, capital goods or as tools for improving business efficiency.

해외 경제충격의 국내 IT제품 수출 파급효과 분석

김원중(Won-Joong Kim) 국제e-비즈니스학회 2009 e-비즈니스 연구 Vol.10 No.2

Non-contact monitoring of the tension in partially submerged, miter-gate diagonals

Brian A. Eick,Matthew D. Smith,Billie F. Spencer 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.27 No.2

Miter gates are water-control structures used as the damming surface on river locks and allow the water levels in the lock to raise or lower as needed. Miter gates have channel-like cross sections and are thus prone to torsional deflection due to gravity loads. To counter-act the tendency for torsional deflection and to add torsional rigidity to the gate, slender steel members termed diagonals are added across the diagonal dimension of the gate and pre-tensioned. To maintain appropriate tension in the diagonals over their lifetime, the tension in the diagonals should be monitored; however, no such monitoring is utilized. Vibration based methods to obtain an estimate of the tensile loads in the diagonal are attractive because they are simple, inexpensive, and do not require continuous monitoring. However, employing vibration-based methods to estimate the tension in the diagonals is particularly challenging because the diagonals are subjected to varying levels of submersion in water. Finding a relationship between the frequency of vibration and applied pretension that adequately addressed the effects of submersion on diagonals is difficult. This paper proposes an approach to account for the effect of submersion on the estimated tension in miter gate diagonals. Laboratory tests are conducted using scale-model diagonal specimens subjected to various levels of tension and submersion in water. The frequency of the diagonal specimens is measured and compared to an approximation using an assumed modes model. The effects of submersion on the frequency of vibration for the partially submerged diagonals are largely explained by added mass on the diagonals. Field validation is performed using a previously developed vision-based method of extracting the frequency of vibration in conjunction with the proposed method of tension estimation of an in-service miter gate diagonal that is also instrumented with load cells. Results for the proposed method show excellent agreement with load cell measurements.

Effects of local structural damage in a steel truss bridge on internal dynamic coupling and modal damping

Hiroki Yamaguchi,Yasunao Matsumoto,Tsutomu Yoshioka 국제구조공학회 2015 Smart Structures and Systems, An International Jou Vol.15 No.3

Structural health monitoring of steel truss bridge based on changes in modal properties wasinvestigated in this study. Vibration measurements with five sensors were conducted at an existing Warrentruss bridge with partial fractures in diagonal members before and after an emergency repair work. Modalproperties identified by the Eigensystem Realization Algorithm showed evidences of increases in modaldamping due to the damage in diagonal member. In order to understand the dynamic behavior of the bridgeand possible mechanism of those increases in modal damping, theoretical modal analysis was conductedwith three dimensional frame models. It was found that vibrations of the main truss could be coupledinternally with local vibrations of diagonal members and the degree of coupling could change with structuralchanges in diagonal members. Additional vibration measurements with fifteen sensors were then conductedso as to understand the consistency of those theoretical findings with the actual dynamic behavior. Modalproperties experimentally identified showed that the damping change caused by the damage in diagonalmember described above could have occurred in a diagonal-coupled mode. The results in this study implythat damages in diagonal members could be detected from changes in modal damping of diagonal-coupledmodes.

Effects of local structural damage in a steel truss bridge on internal dynamic coupling and modal damping

Yamaguchi, Hiroki,Matsumoto, Yasunao,Yoshioka, Tsutomu Techno-Press 2015 Smart Structures and Systems, An International Jou Vol.15 No.3

Structural health monitoring of steel truss bridge based on changes in modal properties was investigated in this study. Vibration measurements with five sensors were conducted at an existing Warren truss bridge with partial fractures in diagonal members before and after an emergency repair work. Modal properties identified by the Eigensystem Realization Algorithm showed evidences of increases in modal damping due to the damage in diagonal member. In order to understand the dynamic behavior of the bridge and possible mechanism of those increases in modal damping, theoretical modal analysis was conducted with three dimensional frame models. It was found that vibrations of the main truss could be coupled internally with local vibrations of diagonal members and the degree of coupling could change with structural changes in diagonal members. Additional vibration measurements with fifteen sensors were then conducted so as to understand the consistency of those theoretical findings with the actual dynamic behavior. Modal properties experimentally identified showed that the damping change caused by the damage in diagonal member described above could have occurred in a diagonal-coupled mode. The results in this study imply that damages in diagonal members could be detected from changes in modal damping of diagonal-coupled modes.

고속 대각 하중 행렬을 이용한 MIMO LTE 프리코딩 코드북

박주용(Ju Yong Park),Bu Shi Peng,이문호(Moon Ho Lee) 大韓電子工學會 2012 電子工學會論文誌-TC (Telecommunications) Vol.49 No.3

본 논문에서는 직교 구조를 갖는 고속 대각 하중 재킷 행렬(DWJM:diagonal-weighted Jacket matrices)을 제안 한다. 고속 알리즘을 이용해 높은 차수의 DWJM을 낮은 차수의 희소 행렬로 분해를 통해 연속적인 DWJM의 계산 수를 줄인다. 원소연산역행렬 특성을 가진 대각 하중 프레임워크(framework)의 결과로, 제안되는 DWJM은 프리코딩(precoding) MIMO(Multiple Input and Multiple Output) 무선통신에 적용된다. DWJM의 성질에 기반하여, DWJM은 대체 오픈 루프 순환 지연 다이버시티(CDD : Cyclic Delay Diversity) 프리코딩으로 사용될 수 있으며, 이는 셀룰러(cellular) 통신 시스템에 이용될 수 있다. 이와같은, DWJM에 기반한 프리코딩 시스템의 성능에 대해 OSTBC (Orthogonal Space-Time Block Code) MIMO LTE 시스템과 비교 한다. In this paper, a fast diagonal-weighted Jacket matrices (DWJMs) is proposed to have the orthogonal architecture. We develop the successive DWJM to reduce the computational load while factorizing the large-order DWJMs into the low-order sparse matrices with the fast algorithms. The proposed DWJM is then applied to the precoding multiple-input and multiple output (MIMO) wireless communications because of its diagonal-weighted framework with element-wise inverse characteristics. Based on the properties of the DWJM, the DWJM can be used as alternative open loop cyclic delay diversity (CDD) precoding, which has recently become part of the cellular communications systems. Performance of the DWJM-based precoding system is verified for orthogonal space-time block code (OSTBC) MIMO LTE systems.

바둑게임의 대각선대칭 반상패턴의 처리

박우전 한국정보기술학회 2014 한국정보기술학회논문지 Vol. No.

In on-board patterns (OBPs) of a go-game, there exist maximum 8 equivalent OBPs - four patterns which are rotation-invariant to one another and four patterns which are diagonally symmetric (mirror-invariant) to each of those rotation-invariant patterns. Previously studied OBP database calculates and stores a representative OBP (ROBP) from 4 rotation-invariants, but it also separately stores the other ROBP of 4 rotation-invariant patterns from a diagonally symmetric pattern to the first stored ROBP; the database stores 8 equivalent patterns as 2 different ROBPs. Above method in the pattern database cannot avoid the storage of pattern duplicates and the inconvenience in retrieving data. In this study, we define the representative diagonally symmetric OBP(RDSOBP) which is the true ROBP for 8 equivalent OBPs, and introduce how to implement RDSOBP database including the insertion and retrieval operation of two diagonally symmetric ROBP patterns. Furthermore, we show the ratio of duplicate storage of two equivalent ROBPs in the existing OBP database and discuss future research in order to increase the reliability of RDSOBP database. 바둑게임의 반상패턴(OBP)에는 최대 8개의 동등한 반상패턴 - 서로 회전불변인 4개의 패턴들 및 이들 각각의 패턴과 서로 대각선대칭(거울불변)인 4개의 패턴- 이 존재한다. 기존의 반상패턴데이터베이스에서 4개의 회전불변인 OBP 중 대표반상패턴 (ROBP)을 계산하여 데이터베이스에 저장하고, 저장된 ROBP와 대각선대칭인 패턴의 4개의 회전불변인 패턴들의 ROBP도 별도로 저장하므로, 결국 8개의 동등한 패턴들은 2개의 서로 다른 ROBP로 저장된다. 기존 데이터베이스에서의 위와 같은 방법은 패턴데이터베이스에서 동등한 패턴의 중복저장, 검색의 번거로움을 피할 수 없다. 본 연구에서는 8개의 동등한 OBP의 진정한 ROBP라 할 수 있는 대표대각선반상패턴 (RDSOBP)을 정의하고, 정의된 패턴을 이용해 서로 대각선 대칭인 반상패턴들의 등록, 검색연산 등 RDSOBP 데이터베이스의 구현방법을 소개한다. 또한 기존 반상패턴데이터베이스에서의 동등한 ROBP의 중복저장 비율을 보이고, RDSOBP 데이터베이스의 신뢰도를 높이기 위해 필요한 연구 등을 논의한다.