• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.1
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• pp.8-13
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• 1988

The botanical, chemical composition and dry matter digestibility of collected herbage samples from sheep fitted esophageal fistula were compared to those of offered herbage samples by the sown pasture, oversown pasture and forest pasture at the 3rd flush stage (25cm grass height). Experimental fields was treated by one plot design and lasted from Aug. 1987 to Oct. 1987 at Chungnam National University, Daejon. The results obtained are summarized as follows: 1. The botanical composition of collected herbage samples was different from offered herbage samples and this difference seemed to depend on diet selection. 2. The sheep consistantly selected more ladino clover than orchardgrass and tall fescue. 3. Crude protein content of collected herbage samples was high (P<0.01) and NDF content was low (P<0.01) on the sown and oversown pastures but forest diets contained more crude fat content (P<0.05) and less crude protein and NDF content (P<0.01) than offered herbage samples. 4. Dry matter digestibility of collected herbage samples was higher than offered herbage samples (P<0.0 1) and this difference was found out among pasture types.

• Steel and Composite Structures
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• v.10 no.1
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• pp.23-43
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• 2010

In this paper, a nonlinear model is developed using the component method in order to represent the response of steel connections under various loading conditions and temperature variations. The model is capable of depicting the behaviour of a number of typical connection types including endplate forms (extended and flush) and angle configurations (double web, top and seat, and combined top-seat-web) in both steel and composite framed structures. The implementation is undertaken within the finite element program ADAPTIC, which accounts for material and geometric nonlinearities. Verification of the proposed connection model is carried out by comparing analytical simulations with available results of isolated joint tests for the ambient case, and isolated joint as well as sub-frame tests for elevated temperature conditions. The findings illustrate the reliability and efficiency of the proposed model in capturing the stiffness and strength properties of connections, hence highlighting the adequacy of the component approach in simulating the overall joint behaviour at elevated temperature.

• Steel and Composite Structures
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• v.8 no.3
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• pp.243-264
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• 2008

This paper details a testing facility ("NATURAL FIRE FACILITY") that allows closely-controlled experimental testing on full-scale sub-frames while reproducing the spatially transient temperature conditions measured in real fires. Using this test facility, an experimental investigation of six steel sub-frames under a natural fire was carried out at the Department of Civil Engineering of the University of Coimbra. The main objective of these tests was to provide insight into the influence of these connection types on the behaviour of steel sub-structures under fire. The experimental layout is defined by two thermally insulated HEA300 columns and an unprotected IPE300 beam with 5.7 m span, supporting a composite concrete slab. Beam-to-column connections are representative of the most common joint type used on buildings: welded joints and extended, flush and partial depth plate. Finally, the available results are presented and discussed: evolution of the steel temperature; development of displacements and local deformations and failure modes on the joints zone.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.9
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• pp.1139-1148
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• 1997

Compression waves propagating in a high-speed railway tunnel develops large pressure fluctuations on the train body or tunnel structures. The pressure fluctuations would cause an ear discomfort for the passengers and increase the aerodynamic resistance of trains. As a fundamental research to resolve the pressure wave phenomenon in the tunnel, experiments were carried out by using a shock tube with an open end. A blockage to model trains inside the tunnel was installed on the lower wall of shock tube, thus forming a sudden cross-sectional area reduction. The compression waves were obtained by the fast opening gate valve instead of a conventional diaphragm of shock tube and measured by the flush mounted pressure transducers with a high sensitivity. The experimental results were compared with the previous theoretical analyses. The results show that the ratio of the reflected to the incident compression wave at the sudden cross-sectional area reduction increases but the ratio of the passing to the incident compression wave decreases, as the incident compression wave becomes stronger. This experimental results are in good agreements with the previous theoretical ones. The maximum pressure gradient of the compression wave abruptly increases but the width of the wave front does not vary, as it passes over the sudden cross-sectional area reduction.

• Journal of the Korean housing association
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• v.4 no.1
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• pp.17-27
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• 1993

The Japanese-style houses built in the colonial age have changed through extension or remodeling since Koreans started residence after the liberation of the country. The objective of this study is to find out the influene of the cultural differences of the two nations on the living-style of the two nations from the comparative living-style viewpoint. 26 Japaneses-style houses built in the Ulsan city from the Open-Port year to 1945 were studied with the field survey method. The qualitative and the quantatative analysis were used. The results of this study are as follows. 1) Because of new materials and conveniences, kitchen, bathroom and toilet have changed into standing-type kitchen, bathroom and bathtub of cement and tile, and flush toilet respectively. The indoor toilets were removed and outdoor ones replaced them instead. 2) In the residential space the Koreans have altered the Dadami-room to the Ondol-room becaus of their own heating wywtem, installed glass or wooden doors for the seperation of rooms, enlarged the indoor space throuh removing walls, and developed new uasge of the Dokonoma space. The room of Zasici is most frequently used as the Korean-style Anbang. The wide space called 'living room' or 'maru' near the entrance hall. In conclusion, the guest-oriented Zasiki-style plan of the Japanese-style houses has remodeled into the family oriented Anbang-style plan.

• Korean Institute of Interior Design Journal
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• no.41
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• pp.11-18
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• 2003

This study was carried out to find the cases of change in the Anglican Church including its rectory in Onsuri, Gangwha island, which was built in Korean traditional architecture style. The materials used for the study were published books, old photos taken before the change, drawings, and field survey. The result are as followings. 1) Painting concealed natural wooden grain should be removed as well as carpet on the wooden floor. The way of ceiling finishing is to be restored as traditional way. 2) Refer to the rectory, it needs to be restored totally, since it has been changed many times through partial renovation. It lacks unification of design in entire elevation, windows and door. The practical spaces such as indoor flush toilet and boiler room are desirable not to be revealed or designed in harmony with other spaces. 3) Stript flooring in the rectory are to be restored to frame flooring, room finishing including vinyl flooring, vinyl wall paper and moulding along the cornice to the traditional paper finish. Lattice patterns of windows and doors are recommended to be restored according to the traditional design.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.8
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• pp.1056-1067
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• 1997

Present study visualized flow pattern and investigated spray characteristics of twin-fluid atomization with converging-diverging nozzles. Particle sizes were measured by using the Malvern particle analyzer, and the radial size distributions were evaluated by using the tomographic transform technique. The results show that the SMD generally increases in the radial direction at a prescribed liquid flow rate and the increasing rate in the SMD becomes gradual as atomizing gas pressure increases. The SMD decreases as the liquid flow rate increases at a fixed GLR (gas/liquid mass ratio). The atomization performance of the protrusion-type nozzle turned out to be superior to that of the flush-type. However, in the case of the protrusion-type, flow separation occurs outside the liquid delivery tube when the pressure at the gas nozzle chamber is high enough, which may deteriorate the atomization performance.

• Journal of Korean Society on Water Environment
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• v.23 no.4
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• pp.423-428
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• 2007

The 21st century is that both human and environment live together. The advancing knowledge concerning our environment instigates a change in understanding about the physical surroundings. The construction field particularly induces significant improvements that are environmental-friendly. To convene this demand, several manuals and guidelines related to the environmental issues have been enacted and amended. Especially the manuals and guidelines issued from Ministry of Environment (MOC) and Ministry of Construction and Transportation (MOCT) is requiring the addition of environmental knowledge in construction technology. Recently, environmental assessments and advanced environmental measures in various kinds of construction are persuasively been carried out. The policy of Total Maximum Daily Load is the one more reason for the revisions of the manual and guideline, which is really requiring the addition of the environmental knowledge in construction technology. Therefore, this research is focusing on revising the manuals and guidelines related to road construction and maintenance works issued from MOCT.

• Steel and Composite Structures
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• v.48 no.5
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• pp.547-564
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• 2023

This study investigates the effect of bolt preloading on the rotational stiffness of stainless steel end-plate connections. An experimental programme incorporating 11 full-scale joint specimens are carried out comparing the behaviours of fully pre-tensioned (PT) and snug-tightened (ST) flush/extended end-plate connections, made of austenitic or lean duplex stainless steels. It is observed from the tests that the presence of bolt preloading leads to a significant increase in the rotational stiffness. A parallel finite element analysis (FEA) validated against the test results demonstrates that the geometric imperfection of end-plate has a strong influence on the moment-rotation response of preloaded end-plate connections, which is crucial to explain the observed "two-stage" behaviour of these connections. Based on the data obtained from the tests and FE parametric study, the performance of the Eurocode 3 predictive model is evaluated, which exhibits a significant deviation in predicting the rotational stiffness of stainless steel end-plate connections. A modified bi-linear model, which incorporates three key properties, is therefore proposed to enable a better prediction. Finally, the effect of bolt preloading is demonstrated at the system (structure) level considering the serviceability of semi-continuous stainless steel beams with end-plate connections.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.1
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• pp.104-110
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• 2006

Growth in population and urbanization has progressively increased the loadings of pollutants from non-point sources as well as point sources. Accordingly, release of contaminants from non-point sources, released with surface runoff of rainwater, is influenced by atmospheric phenomena, geology, and topography. This makes the control of non-point source difficult. Therefore, this study intends to reveal the characteristics of runoff and particle size distribution to observe the fundamental characteristics of runoff. Experiments were carried out at inner road of research center. Average concentration of runoff ranged from 26.8 to 126.4 mg/L for SS and $COD_{Cr}\;15.3{\sim}117.7mg/L,\;TN\;0.07{\sim}5.16mg/L,\;TP\;0.06{\sim}0.49mg/L$ and heavy metals $0.00{\sim}0.29mg/L$. First flush, indicated wash off of pollutant at first rain, was observed for all types of pollutants. Most pollutants revealed a very close correlation with SS ($R^2=0.93{\sim}0.99$). After analyzing characteristics of particle, particle was finer than that from previously examined data.