Seoul Development Institute
Seoul Development Institute
Shim H.B.,Seoul Development Institute |
Park H.S.,Yonsei University
Construction and Building Materials | Year: 2017
To create a joint between reinforced concrete (RC) walls and steel girders in high-rise buildings, the concrete around the embedded plate cannot avoid the damage due to the heat input from a long-time welding (6–48 hours) of the embedded and gusset plates. A literature review showed insufficient research on evaluation of concrete damage due to the welding heat; furthermore, onsite construction workers did not have a clear solution to minimize the damage. In this study, five construction methods with different details are tested to analyze the effect of long-time (approximately 6 hours) onsite welding on the high-strength concrete for the joint between gusset plates and the embedded plate in a high-rise building. Five full-scale specimens with different construction details were tested and analyzed in terms of four items: 1) temperature distribution measurements, 2) compressive strength tests, 3) neutralization tests, and 4) the characteristics of cracks. In this paper, the gusset plates made of SM490 (fy = 325 MPa) were welded over the embedded plates after 28 days of curing of the concrete with a design strength of 55 MPa. Based on the experimental results, it is found that the appropriate selection of construction methods subjected to a long-time onsite welding is to form a gap around the embedded steel plate to minimize the welding heat transfer from the steel plate to concrete. © 2017 Elsevier Ltd
Lim W.,Seoul Development Institute
Asian Economic Policy Review | Year: 2012
Although the degree of sectoral targeting changed dramatically from the 1960s to the 1970s and then from the 1980s onward, Korea maintained an outward-oriented, bottom-up, and integrated approach to industrial policy, relying on close public-private consultation and international benchmarking. The government and the chaebol systematically studied what had to be done to fill the missing links in the domestic value chain and move up the quality ladder, through technology acquisition, human resource development, and construction of optimal-scale plants aimed for the global market. As the capacity of the private sector increased and sectoral targeting became a more difficult proposition, Korea shifted to a more sector-neutral approach, which provided support for industry rationalization and R&D regardless of sectors. This was in line with a larger shift from industrial policy to competition and corporate governance policy, starting with the enactment of the Monopoly Regulation and Fair Trade Act in 1980. © 2012 Japan Center for Economic Research.
Young Do N.,Seoul Development Institute |
International Journal of Environmental Research | Year: 2011
The effect of temperature on the adsorption of heavy metals on not only natural bulk clay, but also for the individual phases that composed the bulk clay sample, was investigated. Combined AdsorptionSequential extraction Analysis (CASA) for Pb, Cu, Zn and Cd were conducted under various temperatures that ranged from 15°C to 55°C. As a result, it was found that heavy metals adsorption for bulk clay increased about 12% when the temperature increased from 15°C to 55°C. The effect of temperature on the individual phases was mainly observed in oxide, including Fe-and Mn-oxide, and the organic phases of all of the metals. As for the Phase Concentration Factors (PCFs) of the metals, the largest increase of the values was observed in the oxide phase. Based on the thermodynamic parameters of the individual phases, the adsorption of metals on natural clay was an endothermic reaction with the exception of exchangeable phase adsorption. This shows mat adsorption affinity and capacity tend to increase when the temperature increase for all adsorption phases of soil, except for adsorption in die exchangeable phase. In the case of Pb, Zn, and Cu adsorption, the considerable enthalpy changes were observed in carbonates, Fe-oxides, and organic phases, which means the adsorption affinity for those phases were largely affected by temperature change. On the other hand, relatively small enthalpy changes in the Cd adsorption were observed in bulk and all individual phases when it was compared with the other metals enthalpy changes for the same phases. This means that Cd adsorption mainly occun-ed in the exchangeable phase, which was affected a little by temperature change.
Kim Y.,Seoul National University |
Kim H.,Seoul National University |
Kim D.-S.,Seoul Development Institute
Psychiatry Research | Year: 2011
Little attention has been paid to whether temperature is associated with suicide and to whether suicide seasonality appears in Asian countries as shown in Western countries, even though suicide rates in Korea have increased steadily. The goal of the present study was to examine the association between daily temperature and daily suicide rate in Korea, taking gender, age, and education level into account. Data were analyzed using a generalized additive model, adjusting for confounding factors such as sunshine, relative humidity, holidays, and long-term trends. Suicide rates were higher in spring and summer than other seasons. We observed a 1.4% increase (95% confidence interval. = 1.0-1.7%) in suicide with each 1 °C-increase in daily mean temperature. The suicide risks related to the temperature for males, elderly people, and those with less education were higher than for females, younger people, and those with more education, respectively. These findings have confirmed that temperature is associated with suicide in Korea and further our understanding of more susceptible groups, the effects of gender, age, and education level. Therefore, temperature, one of the meteorological factors, is an important risk factor on suicide. © 2010 Elsevier Ireland Ltd.
Kim W.,Seoul Development Institute |
Choi J.,Hanbat National University |
Cho H.,Chosun University
Renewable Energy | Year: 2013
A simulation study of hybrid solar-geothermal heat pump system for residential applications using carbon dioxide was carried out under different operating conditions. The system consists of a solar unit (concentric evacuated tube solar collector and heat storage tank) and a CO 2 heat pump unit (three double-pipe heat exchangers, electric expansion valve, and compressor). As a result, the differential of pressure ratio between the inlet and the outlet of the compressor increases by 19.9%, and the compressor work increases from 4.5 to 5.3 kW when the operating temperature of the heat pump rises from 40 °C to 48 °C. Besides, the pressure ratio of the compressor decreases from 3 to 2.5 when the ground temperature increases from 11 °C to 19 °C. The operating time of the heat pump is reduced by 5 h as the daily solar radiation increases. As the solar radiation increases from 1 to 20 MJ/m 2, the collector heat rises by 48% and the maximum collector heat becomes 47.8 kWh. The heating load increases by 70% as the indoor design temperature increases from 18 °C to 26 °C. However, the solar fraction is reduced from 11.4% to 5.8% because of the increases of the heating load. © 2012 Elsevier Ltd.
Park S.W.,Seoul Development Institute |
Park H.S.,Yonsei University |
Kim J.H.,Yonsei University |
Adeli H.,Ohio State University
Measurement: Journal of the International Measurement Confederation | Year: 2015
Unlike 1D or 2D displacement measurement sensors, a motion capture system (MCS) can determine the movement of markers in any direction precisely. In addition, an MCS can overcome the limitations of the sampling frequency in 3D measurements by terrestrial laser scanning (TLS) and global positioning system (GPS). This paper presents a method to measure three dimensional (3D) structural displacements using a motion capture system (MCS) with a high accuracy and sampling rate. The MCS measures 2D coordinates of a number of markers with multiple cameras; these measurements are then used to calculate the 3D coordinates of markers. Therefore, unlike previous 1D or 2D displacement measurement sensors, the MCS can determine precisely the movement of markers in any direction. In addition, since the MCS cameras can monitor several markers, measurement points are increased by the addition of more markers. The effectiveness of the proposed model was tested by comparing the displacements measured in a free vibration experiment of a 3-story structure with a height of 2.1 m using both the MCS and laser displacement sensors. © 2014 Elsevier Ltd. All rights reserved.
Keum K.,Seoul Development Institute
Annals of Regional Science | Year: 2010
International trade represents the transnational flow of merchandise, while international tourism is the flow of humans from one country to another. This paper analyzes the trade and tourism flows to assess whether typical trade theories can be a theoretical basis in explaining tourism flow. Using a panel data analysis approach, this paper examines the gravity model and the Linder hypothesis regarding the two international flows in Korea. The empirical results provide evidence supporting the gravity model in terms of applicability and robustness to the flow of trade and tourism. The Linder hypothesis, however, fails to have the same result. Based on the gravity model, this paper elucidates a general explanation about the patterns of international tourism flows. © 2008 Springer-Verlag.
Kim S.,University of Leeds |
Kim S.,Seoul Development Institute
Singapore Journal of Tropical Geography | Year: 2012
This paper argues for the utility of a focus on contextualized sources of environmental change to address the ever more diverse contexts of political ecology. In order to overcome the conventional approach to contextual sources that has tended to be analytically one-dimensional and limited, I seek to provide a more nuanced account, notably by examining the neglected case of green aid of a nonwestern aid donor, Japan. Using conceptual tools that are both conjuncture-based and multiscalar, the paper examines the way in which a post-Rio international policy drive to promote so called green aid during the 1990s was translated into and conditioned by the historically and geographically specific contexts of Japan and the aid recipient featured herein, the Philippines. This focus on contextual sources helps to elucidate (i) how the ambiguous nature of international aid criteria combined together with Japan's own domestic political economy to render problematic an ostensibly environmental project, (ii) the manner in which neoliberal economic restructuring was translated into one of Japan's key policy initiatives in the 1990s and formed the backdrop to the specific aid case project discussed here, (iii) how Japan's environmental aid process in the Philippines was shaped through a repoliticization of various green discourses, and (iv) how the complex dynamics among stakeholders ended up compromising the very nature of the case study project. © 2012 The Author. Singapore Journal of Tropical Geography © 2012 Department of Geography, National University of Singapore and Blackwell Publishing Asia Pty Ltd.
Lee S.-J.,Sejong University |
Chung H.-K.,Seoul Development Institute
Library and Information Science Research | Year: 2012
Altruism is recognized as a significant component of willingness to pay (WTP) estimates when using contingent valuation method (CVM). The argument of whether all values that are motivated by altruism can be considered as real value has been discussed in various fields. In order to derive the real WTP value for public library valuation, an attempt was made to decompose an individual's total WTP into two categories: local versus global and paternalistic versus nonpaternalistic. A contingent valuation survey was conducted to demonstrate how altruistic motivations affect WTP estimates for public libraries. Approximately 22% of the WTP value was found to be excluded from the total WTP value, because of motivation by local and nonpaternalistic altruistic attitudes. The results suggest that in a WTP study using the contingent valuation method, one must design a survey questionnaire with a comprehensive view that takes into account two different aspects of altruistic motivation. © 2011 Elsevier Inc.
Kim D.-S.,Seoul Development Institute
Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy | Year: 2011
Objective: To examine the prevalence of actual and perceived overweight and to compare the mediating effect of perceived overweight on the relationship between actual overweight and suicidal ideation among young Korean women between 2001 and 2005. Methods: Data were gathered from the 2001 and 2005 Korean National Health and Nutrition Examination Surveys involving a nationally representative sample of young women (568 in 2001 and 385 in 2005) aged 20-29 years. Results: Over the 5-year period, the prevalence of actual overweight (body mass index $23 kg/m2) and perceived overweight increased by 10.5% and 22.8%, respectively. The discrepancy between actual and perceived body weights was much wider in 2005 than in 2001. After controlling for covariates (age, marital status, educational attainment, employment status, smoking status, alcohol consumption, and regular exercise), overweight women were more likely to think about suicide than their normal-weight counterparts in both periods. However, in both periods, the association between overweight and suicidal ideation became nonsignificant when perceived weight was considered. In both periods, a self-perception of overweight was associated with an increased risk of suicidal ideation, but the association was much stronger in 2005 than in 2001. Conclusion: This study suggests a need for educational programs or effective treatments to help young women who perceive themselves as overweight to reduce the potential risk of suicidal ideation in later life. © 2011 Sibal et al.