Monthly Joint Operations for the Nakdong Multi-reservoir System in Korea

Abstract

This study applies a state-of-art optimization technique, SSDP/ESP (Sampling Stochastic Dynamic Programming with Ensemble Streamflow Prediction), to derive a monthly joint operating policy for the Nakdong multi-reservoir system in Korea. A rainfall-runoff model, SSARR (Streamflow Synthesis And Reservoir Regulation), is linked to the SSDP/ESP model to provide ESP scenarios for runoff during the next month in the Nakdong River basin. The primary advantage of the SSDP/ESP is that it updates the derived operating policy as new ESP forecasts become available. Another SSDP model that employs historical runoff scenarios (SSDP/Hist) is also developed. The main difference between the two SSDP models is that SSDP/Hist is an off-line model whereas the SSDP/ESP is on-line. The developed operating policies are tested with a simulation model using an object-oriented simulation software, STELLA. The simulation results show that SSDP/ESP is superior to SSDP/Hist with respect to the water supply criterion, although both models perform similarly with respect to the hydroelectric energy production criterion.     

Are college education and job experience complements or substitutes? Evidence from hedge fund portfolio performance

Review of Quantitative Finance and Accounting - We examine, for various educational characteristics of hedge fund managers, the performance profile of hedge fund portfolios along their...     

Stochastic convergence of the catch-up rate and multiple structural breaks in Asian countries

Allowing for multiple structural breaks and cross-section dependence, we re-investigate the hypothesis that the catch-up rates stochastically converge for 13 Asian countries from 1960 to 2007. Non-rejection of stationarity provides evidence for stochastic convergence, implying that following shocks to the catch-up rate, it will eventually revert to its long-run level.     

The Foundations of International Business: Cross‐Border Investment Activity and the Balance between Market‐Power and Efficiency Effects

The foundational international business (IB) scholarship grappled with whether multinational enterprises (MNEs) are largely efficiency‐enhancing or market‐power inducing institutions. Contemporary scholarship, however, often associates foreign direct investment (FDI) with efficiency‐enhancing properties and thus neglects the market‐power interpretation of the MNE. Such an imbalance is problematic given that the theoretical and empirical justifications behind the field's embrace of the efficiency interpretation are not fully evident. Instead, both efficiency and market‐power effects are seemingly present in cross‐border investment activity. Based on a comprehensive sample of up to 4,361 cross‐border investments materializing between 1986 and 2010, we present theoretically‐grounded hypotheses with regard to when market‐power effects will tend to dominate efficiency effects. We find that cross‐border investments undertaken by emerging‐market MNEs in both developed and emerging markets tend to involve substantial efficiency effects and minimal market‐power effects when compared with the cross‐border investments undertaken by developed‐country MNEs in both developed and emerging markets.     

Modernization and dependency revisited: U.S. direct investment,development, and polity in Latin America, 1950–1998*

Since World War II, the modernization model has been the mainstream paradigm for economic development. Modernization assumes that foreign capital is a necessary catalyst for transforming societies from traditional to modem. Challenges to the modernization paradigm culminated in dependency theory. Dependency theorists point to detrimental effects of foreign capital and domination (e.g., income inequality, authoritarianism, and inappropriate consumption). Despite the charge by many scholars that this debate has subsided, basic but important questions remain to be answered. This paper assesses the role of U.S. direct investment (USDI) on the major economies of Latin America over time (1950–1998). Using Vector Autoregression, we look at the long‐term political relationships between USDI, economic development, and the degree of authoritarianism in the host country's government. We treat these variables as endogenous as both dependency and modernization hypothesize relationships among them. We find that there are only weak long‐term relationships between polity, development, and USDI. These results fully support neither the modernization nor the dependency model.     

Export composition and growth of selected low-income African countries: evidence from time-series data

This paper examines the hypothesis that economic growth is linked to export composition with the use of time-series data for some low-income African countries. On the basis of the regression results, the study supports the hypothesis of a positive linkage between the growth of non-fuel primary exports and growth. However, the results cast some doubt on the significance of the positive contribution of the manufactured exports sector to the growth process of the low-income African countries.     

CROSS‐COUNTRY TECHNOLOGY TRANSFER AND POLITICALLY DRIVEN INTERNATIONAL AGREEMENTS FOR ENVIRONMENTAL STANDARDS

Grossman and Helpman highlighted a political framework to internalize inefficiency incurred due to unilateral trade policy implementation by sovereign countries. This paper extensively adopts their framework to explore the effects of special interest politics on governments under negotiation to forge international environmental standards to control global emission. Particular attention is given to a case in which negotiation is driven by transferring the abatement technology. Within a specific factor model of international trade, improving the abatement efficiency through technology transfer can give the most mutually beneficial outcome, achieving the lowest level of global pollution compared to other political benchmarks.     

Change in fish community composition following weir removal,field observations,and physical habitat simulations

The number of untended weirs has increased in Korea in recent years due to land use changes. The removal of abandoned weirs in streams has been attempted following an agreement between local government and residents. The Gongneung Weir‐2 was built for irrigation in the 1970s and was removed in 2006. The objective of this study was to investigate the impact of the removal of Gongneung Weir‐2 on the composition of the fish community. The study area was a 900‐m‐long reach in the Gongneung‐cheon River in Korea, and Gongneung Weir‐2 was located in the middle of the reach. Before weir removal, field monitoring revealed that five fish species were dominant and accounted for more than 80% of the entire fish community. The composition of the fish community changed significantly after weir removal. Lotic fish became dominant after weir removal, whereas lentic fish were dominant prior to weir removal. Physical habitat simulations (PHSs) for individual dominant fish species were carried out. For the PHS, the River2D model and the adaptive neuro‐fuzzy inference system method were used for hydraulic and habitat simulations, respectively. The distributions of the highly suitable portion for each fish species were identified before and after weir removal. The PHS successfully predicted changes in the composition of the fish community after weir removal. The PHSs for the entire fish community and for the lotic and lentic guilds were undertaken and the simulated results were compared with each other. The PHSs for the entire fish community could not account for the less dominant fish species in the fish community.     

The changing dynamics of regionalism in South Korea's elections

One of the most persistent areas of discussion regarding South Korea's party and election systems is the continued elevation of regional personalities over political institutions. We seek to pour new wine into old bottles, however, by challenging a seldom‐considered assumption in Korean studies; that regionalism has exerted constant pressures across regime, province, and personality. There is a void in studying how transition to democracy has affected the dominance of personality‐based regionalism in Korean politics. We investigate democratization's impact on this phenomenon by examining the provincial distribution of legislative and presidential voting from 1971–2002. We employ a new indicator for personality‐based disproportionality, apply it to election outcomes at the provincial level, and find that the electoral impact of regionalism has changed over time across regimes, provinces, and political personalities. We find that regional voting disproportionality 1) increased immediately after transition; 2) has varied depending on personality and type of election; 3) is indeed low in provinces traditionally labeled as neutral; and 4) increased in the 2000 legislative election while declining in the 2002 presidential election.