• Journal of Korean Society of Steel Construction
• /
• v.21 no.3
• /
• pp.267-275
• /
• 2009

This paper presents the behavior of column-removed double-span beams in welded steel moment frames and proposes a simplified nonlinear dynamic analysis method for the preliminary evaluation of progressive collapse potential. The nonlinear finite element analysis and the associated analytical study showed that the column gravity load and the beam span-to-depth ratio govern the maximum dynamic deformation demand of the double-span beams. Based on these results, the concept of a collapse spectrum, which describes the relationship between the gravity load parameter and the maximum chord rotation of the double-span beams, was newly proposed. A procedure for the application of the collapse spectrum to multi-story welded steel moment frames was then suggested. The inelastic dynamic finite element analysis results showed that the proposed method gives satisfactory prediction of the nonlinear progressive collapse behavior of welded steel moment frames.

• Journal of the Korea Furniture Society
• /
• v.19 no.4
• /
• pp.273-282
• /
• 2008

Increasing demand for timber and the depletion of natural forest have encouraged utilization of many non-popular species. The understanding of wood properties and behavior is important to evaluate the potential of these species to produce high quality end products. This study determines the anatomical and physical properties of Hevea species viz Hevea pauciflora, Hevea guianensis, Hevea spruceana, Hevea benthamiana and Hevea brasiliensis. Each sample tree was cut into three different portions along the height (bottom- B, middle- M and upper -T parts) and two radial samples (outer- O and inner- I parts). H. brasiliensis clone RRIM 912 exhibited the longest fibre with $1214{\mu}m$, followed by H. benthamiana (HB, $1200{\mu}m$), H. pauciflora (HP, $1189{\mu}m$), H. spruceana (HS, $1158{\mu}m$) and H. guianensis (HG, $1145{\mu}m$). Fibre length has a positive correlation with specific gravity. The largest fibre diameter ($24.9{\mu}m$) and lumen diameter ($12.5{\mu}m$) were recorded in H. guianensis. The highest moisture content was obtained from H. spruceana (64.34%) compared to the lowest with 60.01% (Clone RRIM912). The higher moisture content is normally associated with lower strength. Overall, the properties of clone RRIM 912 is found to be comparatively better because of higher strength due to longer fibre length, thicker cell walls and higher specific gravity than the other Hevea species. Therefore, this species can be used as a general utility timber.

• Journal of Forest and Environmental Science
• /
• v.39 no.1
• /
• pp.55-64
• /
• 2023

Properties of a lesser-used wood species were investigated to determine its potential for structural utilization. Trees of Delonix regia were felled and sampled at the base, middle and top and then sectioned to inner wood, middle wood, and outer wood for variation across the axial and radial directions. Hence, selected physical and mechanical properties as well as natural durability of D. regia along the radial and axial directions were examined. Obtained data were analyzed using analysis of variance (ANOVA) at α_0.05. There was no significant difference in the Moisture content (MC) of the wood but specific gravity (SG) decreased from base to top ranging from 0.35-0.44. Water absorption, volumetric swelling, and volumetric shrinkage range from 46.18-51.86%, 2.57-4.02%, and 2.26-3.96% respectively along the axial plane. The weight loss for graveyard exposure and accelerated laboratory decay test ranged from 25.14-48.00% and 32.02-44.45% respectively. Modulus of Rupture and Modulus of Elasticity values range from 29.42-72.68 Nmm² and 3,834.54-8,830.37 Nmm² respectively. The SG values has confirmed the species as a medium density wood and values of other properties tested showed that the wood is dimensional stable and moderately resistance to fungi and termite. Hence, it could be used for light construction purposes such as furniture and other interior woodwork.

• Journal of the Korean Society of Food Culture
• /
• v.25 no.1
• /
• pp.47-53
• /
• 2010

This study was conducted to investigate the effects of saltwort, on the quality characteristics of sponge cake. In addition, we examined the commercialization potential of sponge cake containing saltwort. To accomplish this, saltwort was added to sponge cakes at concentrations of 0%, 3%, 5% and 7% and quality and sensory tests were then conducted. The 7% group had the highest water and ash content. There was no difference in the fat content between samples. The control group showed the highest protein content and the lowest specific gravity. As the content of saltwort increased, the specific gravity of the sponge cake increased. Additionally, the dough yield and loss during baking were highest, in the control group, and these values decreased as the saltwort content increased. Similarly, the volume and specific volume were highest in the control group, and these values decreased as the content of saltwort powder increased. Color measurements of the samples, revealed that the L-value decreased as the content of saltwort powder increased. Furthermore, the a-value of the saltwort powder groups was higher than that of the control group and the b-value was highest in the 7% group. There were no differences in elasticity and cohesion between samples, but chewiness and brittleness increased the content of saltwort powder increased. The results of the sensory test revealed that the color, flavor and taste scores were the highest in the 5% group. The pore size was greatest in the control group, while hardness was greatest in the 7% group, chewiness was highest in the 5% group and moistness was highest in the 5% group. Finally, the overall preference was for the 5% group.

• East Asian Economic Review
• /
• v.20 no.3
• /
• pp.279-309
• /
• 2016

The proposed Trans-Pacific Partnership (TPP) is a free trade agreement among 12 Pacific Rim countries whose joint gross domestic products (GDPs) account for 36 percent of world GDP and whose mutual trade accounts for approximately 24 percent of world trade. As for most proposed free trade agreements (FTAs), trade economists have provided ex ante computable general equilibrium (CGE) estimates to predict the trade, employment, and real per capita income effects of this agreement, such as ITC (2016). This paper-intended to complement these studies-examines the potential impacts of TPP beyond such traditional CGE estimates, taking a broader economic, governance, and historical perspective. First, we contrast these traditional CGE trade and welfare estimates that treat all firms within an industry as homogeneous with more recent CGE analyses that allow firms' productivities to be heterogeneous. We show that the latter models' trade predictions are much more consistent with ex post empirical evidence of average trade effects of FTAs. Second, empirical evidence now strongly confirms the existence of FTA "contagion." We review this evidence and show that predictive models of the evolution of FTAs indicate that the TPP should be formed. With China now having formed 12 FTAs and negotiating five new ones (including a sixteen member Asia-Pacific FTA), the United States would likely face considerable trade diversion without the TPP. Third, we examine empirical evidence on the likely further economic growth implications of FTAs by reducing firms' uncertainty over trade relations and trade policies. Fourth, we examine empirical evidence on the additional impact of FTAs on consolidating democratic institutions in countries. The TPP would likely help consolidate some of the less mature democracies. Fifth, we examine empirical evidence on the reductions of conflicts (and enhanced peace) between countries owing to the formations of FTAs. We conclude the paper noting that the potential net benefits to member countries of the proposed TPP extend well beyond the real income gains to households based upon traditional CGE models.

• Journal of Korea Trade
• /
• v.26 no.1
• /
• pp.20-32
• /
• 2022

Purpose - This paper intends to make theoretical analysis and empirical test on the factors influencing China's export to South Korea, and draw conclusions about China's export efficiency and trade potential. Based on the conclusions, the reasons for China's trade deficit with South Korea are found, and a solution is put forward for solving the problem of China's trade deficit with South Korea. Design/methodology - Based on the data of 2004-2017 years in China, this paper uses the stochastic frontier gravity model to analyze the influencing factors of China's export to South Korea, as well as the export efficiency of each province and the export potential that can be explored. Findings - First, in terms of the factors affecting China's export trade to South Korea, the GDP of the provinces and cities in China, the FDI of South Korea to the provinces and cities in China, the GDP of South Korea, the population and education level of provinces and cities in China can significantly promote the export scale of Chinese provinces and cities to South Korea. The distance between Chinese provincial capitals and the South Korean capital significantly hinders Chinese exports to South Korea; Second, in terms of export trade efficiency, the trade exchange rate of the economically developed cities along the eastern coast of China and several provinces that are close to South Korea is higher than that of the cities in the central and western regions; Third, economic globalization makes trade more convenient, the average export trade efficiency of China's exports to South Korea showed an upward trend. However, under the influence of the 2008 global financial crisis, the export trade efficiency declined from 2008 to 2009, indicating that the impact of the financial crisis on the trade efficiency cannot be ignored. Originality/value - This paper finds out the influencing factors of China's export to South Korea, analyzes the export efficiency of different provinces and cities, excavates the export potential, and puts forward some suggestions for the balanced development of China and South Korea trade in the next step.

• Journal of the Korean earth science society
• /
• v.29 no.1
• /
• pp.1-12
• /
• 2008

A geophysical mapping was performed for Hwasan caldera which is located in Euisung Sub-basin of the southeastern part of the Korean Peninsula. In order to overcome the limitation of the previous studies, remote sensing technic was used and dense potential data were obtained and analyzed. First, we analyzed geological lineament for target area using geological map, digital elevation model (DEM) data and satellite imagery. The results were greatly consistent with the previous studies, and showed that N-S and NW-SE direction are the most dominant one in target area. Second, based on the lineament analysis, highly dense gravity data were acquired in Euisung Sub-basin and an integrated interpretation considering air-born magnetic data was made to investigate the regional structure of the target area. The results of power spectrum analysis for the acquired potential data revealed that the subsurface of Euisung Sub-basin have two density discontinuities at about 1 km and 3-5 km depth. A 1 km depth discontinuity is thought as the depth of pyroclastic sedimentary rocks or igneous rocks which were intruded at the ring vent of Hwasan caldera, while a 3-5 km depth discontinuity seems to be associated with the depth of the basin basement. In addition, three-dimensional gravity inversion for the total area of Euisung Sub-basin was carried out, and the inversion results indicated two followings; 1) Cretaceous Palgongsan granite and Bulguksa intrusion rocks, which are located in southeastern part and northeastern part of Euisung Sub-basin, show two major low density anomalies, 2) pyroclastic rocks around Hwasan caldera also have lower density when compared with those of neighborhood regions and are extended to 1.5 km depth. However, a poor vertical resolution of potential survey makes it difficult to accurately delineate the detailed structure caldera which has a vertically developed characteristic in general. To overcome this limitation, integrated analysis was carried out using the magnetotelluric data on the corresponding area with potential data and we could obtain more reasonable geologic structure.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.4
• /
• pp.391-395
• /
• 2012

We present a continuous cell separator that achieves density-dependent and size-independent cell separation based on the net force of gravity and buoyancy forces on the cells in dissimilar density fluids. Previous cell separators are, based on the size or dielectrophoretic property of the cells and, are suitable for size-dependent and density-independent cell separation. However, these properties can make it difficult to collect the same types of cells with the same density but with size variations. The present separator, however, is capable of collecting the same types of cells based on the cell density in the fluid. Regardless of cell size, the proposed chip isolates low density cells, (white blood cells, or WBCs) at the upper outlet while obtaining high-density cells (red blood cells, or RBCs) from the lower outlet based on density. Efficiency levels for separation of WBCs and RBCs were $90.9{\pm}9.1%$ and $86.4{\pm}1.99%$, respectively. The present separator therefore has the potential for use in the pretreatment of whole blood.

• The Journal of the Korea Contents Association
• /
• v.17 no.7
• /
• pp.283-293
• /
• 2017

This study analyzed the actual conditions of use of public sports facilities and characteristics of the users of the facilities through surveys and measured the spatial imbalance of the public sports facilities currently supplied by using gravity potential model. This study also suggests evaluation criteria that may be considered for efficient location selection by examining the change of accessibility to the facilities that meet the needs of users in the future. As the results of the questionnaire survey, unlike current usage, the users hoped for badminton, weight training and swimming. And we could confirm the demand for the expansion of the multi - purpose indoor gym which can carry out such activities in the areas. As the result of the analysis on the difference in accessibility of the public sports facility, there were some large variations in the regions. It was found that a balanced supply of facilities was needed in terms of equity. In particular, when analyzing by considering the population estimates of 2025, It is analyzed that the accessibility will be reduced to about 60% compared to that of 2015. In addition, it is evaluated as the best alternative in terms of overall efficiency that the location of the facilities should be in Munsan area where population growth is expected in the future.

• Journal of the Society of Naval Architects of Korea
• /
• v.30 no.2
• /
• pp.112-122
• /
• 1993

A potential-based panel method is presented for the analysis of a partially or supercavitating two-dimensional hydrofoil at a finite submergence beneath a free surface, treating without approximation the effects of the finite Froude number and the hydrostatic pressure. Free surface sources and normal dipoles are distributed on the foil and cavity surfaces, their strength being determined by satisfying the kinematic and dynamic boundary conditions on the foil-cavity boundary. The cavity surface is determined iteratively as a part of the solution. Numerical results show that the wave profile is altered significantly due to the presence of the cavity. The buoyancy effect due to the hydrostatic pressure, which has usually been neglected in most of the cavitating flow analysis, is found playing an important role, especially for the supercavitating hydrofoil; the gravity field increases the cavity size in shallow submergence, but decreases it when deeply submerged, while the lift reduces at all submergence depth.