• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.4
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• pp.187-192
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• 2023

An elastic bearing must be strong against vertical loads and flexible against horizontal loads. However, due to the material characteristics of rubber, it may show variability due to the manufacturing process and environmental factors. If the value applied in the bridge design stage and the actual measured value have different values or if the performance during operation changes, the performance required in the design stage may not be achieved. In this paper, the seismic response of bridges was compared and analyzed by assuming a case where quality deviation occurs during construction compared to the design value for elastic bearings, which have not only always served as traditional bearings but also have had many applications in recent seismic reinforcement. The bearing's vertical stiffness and shear stiffness deviation were considered separately for the quality deviation. In order to investigate the seismic response, a time history analysis was performed using artificial seismic waves. The results confirmed that the change in the bearing's shear stiffness affects the natural period and response of the structure.

• Journal of Korea Technology Innovation Society
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• v.12 no.3
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• pp.662-686
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• 2009

Lately innovation is perceived as a systemic, horizontal phenomenon and requires a new governance for innovation. Subsequently, broader societal questions enter the domain of innovation policy and coordination and integration between innovation policy and various other policy domains, such as economic, educational, social, regional and environmental policies become crucial. Definitions of policy integration include terms such as coherence, cooperation, coordination and put great emphasis on joint working to promote synergies among policies and reduce duplication and the use of the same goals to formulate policy. As innovation capabilities of the private sector have improved and it has become unclear who to catch up with, the Korean government, a leading player in the process of "catch-up," is likely to have more difficulties in maintaining the old way of planning and executing policies. The Korean government is now under the pressure of planning technologies and policies that do not allow any easy imitation or copy of other advanced countries longer, which in turn reveals various limits of the existing policy framework. Policy integration involves a continual process demanding changes in political, organizational and procedural activities. To ensure long term and cross sectoral innovation policy, overall change and improvement in policy and its implementation needed in terms of political commitments, governance systems, policy instruments and monitoring, and evaluation systems.

• Journal of the Korean housing association
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• v.18 no.1
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• pp.141-148
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• 2007

In this research, to develope wooden house model with post & beam structure which is commensurate with domestic environment, we analyzed the size and module of a unit space and space organization of existing habitation, then, based on the result, we tried to suggest general wood house modules. For this, we investigated 98 floor plans for 30 pyeong apartment in Seoul, Gyounggi-do, Gwangju, and Jeolla-do. The results are showed as follows. 1) It has shown that 7 posts distances are available in 2 bay floor plan type - 3.0 m, 3.3 m, 3.6 m, 3.9 m, 4.2 m, 4.5 m, and 4.8 m. 2) It has shown that 8 posts distances are available in 3 bay floor plan type - 3.0 m, 3.3 m, 3.6 m, 3.9 m, 4.2 m, 4.5 m, 4.8 m, and 5.1 m. It was concluded as follows, applying the standard of regulations of horizontal modular coordination design, from $\ulcorner$the standard of modular coordination design in architecture(KSF 1525)$\lrcorner$. 1) The available widths are 3.0 m, 3.3 m, 3.6 m, 4.2 m, and 4.8 m, and the available depths are 3.0 m, 3.3 m, 3.6 m, and 4.2 m. 2) To guarantee a space through post module of a room combination, we can use a module of 3.6 m, 4.2 m, 4.8 m except 3.0 m, 3.3 m among available modules. The module investigated in post & beam structure wooden house is applied in basic 6 floor plans as follows. 1) When organize the room on the basis of tile module of 3.6 m, 4.2 m, it was possible to organize the floor plan. 2) After arranging main room, making practical application of variableness which is advantage of post & beam structure, putting to practical use of extra space that becomes the combination of atypical room such as kitchen, dining room, and bathroom, it was possible to organize the floor plan of the residence. 3) It is possible to organize whole rooms through the plan module from 3.6 m to 4.2 m, that decides the floor plan of a wooden house.

• Journal of the Korean Geotechnical Society
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• v.37 no.11
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• pp.37-49
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• 2021

Micropiles are widely used in construction field to enhance bearing capacity and reduce settlement of existing foundation. It has various benefits such as low construction expense, simple installation process, and small construction equipment. Recently, new microple equipped with the base expansion structure at the end has been developed to improve the foundation bearing capacity. The improvement of load capacity can be conceptually achieved by expanding the base expansion structure when a load is applied to the micropile. However, the expansion mechanism of the base expansion structure and the improvement of load capacity of the micropile were not yet experimentally validated. Therefore, in this study, a series of centrifuge model tests was performed to evaluate the effect of the base expansion structure on the improvement of load capacity. Two types of soil, sand and weathered rock, were prepared and the loading tests were performed using the real micropile with the base expansion structure. During the tests, the earth pressures surrounding the base expansion structure were monitored. As a result, when a load of 30 kN was applied to the micropile, the increase in the ratio of the horizontal to vertical pressure increment (∆σ_h/∆σ_𝜈) ranged from 0.4 to 0.58 in sand and ∆σ_h/∆σ_𝜈 = 0.19 in weathered rock, respectively. Therefore, it can be concluded that the increase in the horizontal earth pressure adjacent to the base expansion structure will improve the bearing capacity of the micropile.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5148-5154
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• 2012

The purpose of this study was to analyze the kinematic characteristics of the thrower's center of mass (COM) and the shot that her performance hits record high for the 29th National Athletic Competition. Two S-VHS video cameras were used to visualize. The Direct Linear Transformation technique was employed to paint a clear picture in the three dimensional coordination. Kwon3D was used to analyze the data. The results showed that release velocity and height were 13.73 m/s and 198.6 cm(119% by height ratio), respectively, which is considered as peak performance comparing an extensive review of previous literature on the shot put. Release angle was $34^{\circ}$, which is lower than the previous studies. The path of thrower's center of mass is needed to travel in a release direction during the flight phase. The vertical movement of the thrower's center of mass during the driving should be controlled. At release, the perfact timing is required without vertical and horizontal movements of the thrower's center of mass.

• Journal of Environmental Impact Assessment
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• v.23 no.2
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• pp.119-136
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• 2014

This work aims to select the potentially vulnerable plant species against climate change at alpine and subalpine belts of Mts. Sorak, Jiri, and Halla, from central, southern, southern insular high mountains of the Korean Peninsula, respectively. The selection of global warming related vulnerable plants were performed by adapting various criteria, such as flora, endemicity, rarity, floristically specific and valuable species, species composition at mountain summits, horizontal and vertical ranges of individual species, and their distributional pattern in the Korean Peninsula. Line and quadrat field surveys along the major trails from all directions at height above 1,500 meters above sea level of Mts, Sorak, Jiri and Halla were conducted each year during spring, summer, and autumn from 2010 to 2011. Based upon above mentioned eight criteria, high level of climate change related potentially vulnerable arboral plants, such as Rhododendron aureum, Taxus caespitosa, Pinus pumila, Oplopanax elatus, Vaccinium uliginosum, and Thuja koraiensis are noticed from at subalpine belt of Mt. Sorak. Species of Abies koreana, Rhododendron tschonoskii, Oplopanax elatus, Taxus cuspidata, Picea jezoensis, and Juniperus chinensis var. sargentii belong to climate change concerned vulnerable species at subalpine belt of Mt. Jiri. High level of climate change related species vulnerability is found at alpine and subalpine belts of Mt. Halla from Diapensia lapponica var. obovata, Salix blinii, Empetrum nigrum var. japonicum, Vaccinium uliginosum, Juniperus chinensis var. sargentii, Taxus cuspidata, Rhamnus taquetii, Abies koreana, Hugeria japonica, Prunus buergeriana, and Berberis amurensis var. quelpartensis. Countermeasures to save the global warming vulnerable plants in situ are required.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.6
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• pp.653-663
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• 2014

To cope with an increasing amount of data traffic, research efforts are being made to maximize the data rate by reducing the interference between the transmission nodes. This paper also focuses on interference control schemes utilizing antenna sub-array beam-forming. The first scheme relies on horizontal beam rotation which utilizes three types of narrow beam patterns. Different beam patterns are applied to transmit signals in rotating fashion to control the interference. The second scheme is based on user-specific sub-array beamforming, which uses the precoding matrix based on users' location and controls the amount of interference in the multi-user environment. The performance of the proposed schemes is evaluated using the computer simulation to demonstrate the performance enhancement.

• Advances in Computational Design
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• v.4 no.2
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• pp.119-139
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• 2019

Planning and management building projects should tackle the coordination of works and the management of limited spaces, traffic and supplies. Activities cannot be performed without the resources available and resources cannot be used beyond the capacity of workplaces. Otherwise, workspace congestion will negatively affect the flow of works. Better on-site management allows for substantial productivity improvements and cost savings. The procurement system should be able to manage a wider variety of materials and products of the required quality in order to have less stock, in less time, using less space, with less investment and avoiding multiple storage stations. The objective of this paper is to demonstrate the advantages of using the Chronographic modeling, by combining spatiotemporal technical scheduling with the 4D simulations, the Last Planner System and the Takt-time when modeling the construction of building projects. This paper work toward the aforementioned goal by examining the impact that material flow has on site occupancy. The proposed spatiotemporal model promotes efficient site use, defines optimal site-occupancy and workforce-rotation rates, minimizes intermediate stocks, and ensures a suitable procurement process. This paper study the material flow on the site and consider horizontal and vertical paths, traffic flows and appropriate means of transportation to ensure fluidity and safety. This paper contributes to the existing body of knowledge by linking execution and supply to the spatial and temporal aspects. The methodology compare the performance and procurement processes for the proposed Chronographic model with the Gantt-Precedence diagram. Two examples are presented to demonstrate the benefits of the proposed model and to validate the related concepts. This validation is designed to test the model's graphical ability to simulate construction and procurement.

• Journal of Korea Trade
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• v.24 no.6
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• pp.115-134
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• 2020

Purpose - International trade leads to the international division of labor, improving the efficiency of the global economic system. Transport costs are a more serious barrier to international trade than customs tariffs. An increase in competition in the transport sector may thus lead to a reduction in transport costs. However, if a carrier's nationality significantly influences transport costs, simply adding more competing carriers of different nationalities would be ineffective. Therefore, it is necessary to establish national or regional carriers to influence competition and reduce transport costs. This study investigates this "nationality effect" by treating Hanjin Shipping's collapse as a natural experiment. Design/methodology - The theoretical basis of this study is the 3rd-degree price discrimination in container shipping market. By using the monthly data of container freight rates of Korea, China and Japan, this study shows the so-called Korea Premiums, which are the empirical counterparts of nationality effect in Korea container shipping market. For this empirical investigation, the structural model with state-space form is used and the dummy models are also estimated. In addition, because China has been also affected by the Hanjin's collapse, the China premiums are considered too. Findings - Compared with Japan's case, it is shown that there had been the so-called Korea premiums since the collapse of Hanjin Shipping. These results are robust from both the state-space model and dummy models. The time pattern of Korea premiums was consistent with the market evolution, especially the pattern of substitutability in container shipping markets. In addition, this paper shows the magnitude of Korea premiums. Originality/value - The argument of this study that the nationality effect can be interpreted as an extended concept of the home market effect is original, which is expected to evoke future research efforts. Further, the discussion on the shipping industrial policy from both horizontal and vertical aspects will provide the relevant policy makers with solid information, especially for the policy coordination in a global scale.

• Journal of the Korean Geotechnical Society
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• v.26 no.11
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• pp.29-38
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• 2010

The steel pipe of steel-concrete composite piles increases the pile strength and induces the ductile failure by constraining the deformation of the hiller concrete. In this research, the load-movement relations and the reinforcement effect by the outer steel pipe in the steel-concrete composite pile were analyzed by performing three-dimensional numerical analyses, which can simulate the yielding behavior of pile material and the elasto-plastic behavior of soils. The parameters analyzed in the study include three pile materials of steel, concrete and composite, pile diameter, pile distance and loading direction. The results showed that the axial capacity of the composite pile was about 90% larger than that of the steel pipe pile while similar to that of the concrete pile. At the allowable movement criteria, the horizontal capacity of the composite pile was about 50% lager than that of the steel pile and about 22% larger than that of the concrete pile.