• 대한족부족관절학회:학술대회논문집
• /
• 2011.04a
• /
• pp.5-5
• /
• 2011

• Magazine of the Korea Concrete Institute
• /
• v.15 no.3
• /
• pp.93-97
• /
• 2003

• Life and Agrochemicals
• /
• s.255
• /
• pp.38-40
• /
• 2010

합성염료는 아버지요, 합성의약은 아들, 합성농약은 손자의 괸계가 된다. 일견, 닮을래야 닮을수 없을 것 같은 부자지간으로 보이지만, '선택성'이라고 하는 가장 중요한 유전자를 계승하며, 의약에서 농업으로 발전시켜 왔던 것이다.

• Journal of the Economic Geographical Society of Korea
• /
• v.13 no.2
• /
• pp.181-195
• /
• 2010

The policy of industrial complexes (innovative clusters) is being changed to build the linkage structure within Mega Economic Region according to the national policy of Mega Economic Region. The aim of this analysis is to draw the hypothetical linkage structure of industrial complexes in the internal and external Capital Region. First, with the survey data of firms located in the industrial complexes, we can catch the regional linkages of firms in the local area and internal and external Mega Economic Region. Next, the measure of structural similarity between industrial complexes is calculated with the number of employees by industrial sectors. After considering the geographical distance between industrial complexes, the percentage of industrial sectors and the location quotient synthetically, the idea of hub-and-spoke type linkage structure between clusters is deduced.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.1A
• /
• pp.55-64
• /
• 2012

Experimental investigation on the structural behavior of steel fiber-reinforced ultra high performance concrete (UHPC) beams subjected to shear are presented. Six tests carried out on simply supported I-beams under concentrated loads are presented. The parameters varied were the volume fraction of the fibers (1.0, 1.5 and 2.0%) and shear span-effective depth ratio (2.5, 3.4). The test results indicated that ultimate shear strength increased with increasing fiber volume, and that ultimate shear strength decreased with increasing shear span-effective depth ratio. In addition, applicability of predictive equations for evaluating the ultimate shear strength of steel fiber-reinforced UHPC beams are estimated based on the test results. The comparison between computed values and the experimentally observed values are shown to validate the proposed theoretical equations. It is found that predictions by using AFGC and JSCE recommendations provide the most accurate estimates of shear strength of steel fiber-reinforced UHPC beams.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.11 no.4
• /
• pp.55-66
• /
• 1991

Presented is a study on the realistic determination of design loads and design criteria for bridge structures. The current bridge design code does not consider realistically the uncertainties inherent in loads and resistances and thus the level of safety varies greatly among the bridge spans. The resonable bridge design loads and design criteria which exhibit uniform reliability among various bridge spans are therefore derived in the present paper. The proposed design loads are determined from the analysis of numerous data obtained from actual traffic survey and the design criteria are based on the advanced concept of load and resistance factor format. The live load factors take into account resonably the effects of traffic volume increase. The proposed design loads and design criteria show uniform safety level for various bridge spans and reasonably consider the effects of traffic volume increase. The present study provides useful and valuable data for new version of our bridge design code.

• Magazine of the Korea Concrete Institute
• /
• v.6 no.2
• /
• pp.180-187
• /
• 1994

Sixteen reinforced concrete beams were tested statically up to failure to investigate the arch action. Major variables were the shear span to depth ratio, steel ratio and existence of stirrups.The arch action in reinforced concrete beams started when flexural cracks appeared at the center of the span. Due to the reduction of internal moment arm length by the development of arch action, the measured steel tension was significantly higher than the calculated. As the shear span to depth ratio arid steel ratio decrease, the arch action in reinforced concrete eams increases. Over the entire length the force in the steel of no web reinforced beams having smaller a /d ratio than 3 was constant because the beams acted as a tied arch.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.217-220
• /
• 2008

A modified FRP-concrete composite deck applicable to cable stayed bridge with long girder-to-girder span is proposed, and its design and economical efficiency are presented. The existing FRP-concrete composite deck has low section stiffness due to adoption of GFRP panel with low elastic modulus, which arrives at difficulty in meet of serviceability limit such as deck deflection. So a new-type FRP-concrete composite deck, named precast FRP-concrete deck, is developed by extensioning concrete at the both ends of FRP-concrete composite deck, which brings the effect of reduction of net span length of deck. Compared to the existing FRP-concrete composite deck this modified deck has the advantage of increasing span length but slightly increases self weight. For this type of deck the section optimization is carried out for the cases of simply supported on girder and composite to girder. The optimized deck was applied to cable stayed bridge with a center span length of 540m, and as a result it is verified that PFC deck can be applied efficiently to cable stayed bridge due to reduction of quantity of upper structure.

• Journal of the Korea Concrete Institute
• /
• v.19 no.3
• /
• pp.275-281
• /
• 2007

Recently, steel-concrete composite structures are widely used in bridge and building constructions. In this paper, a new type of steel-concrete composite deck with profiled steel sheeting is proposed to replace the conventional cast-in-place reinforced concrete deck. Perfobond rib shear connectors were utilized to provide horizontal shear resistance between the profiled sheeting and the concrete. To validate the effectiveness of the proposed deck system, 8 full-scale deck specimens for PSC girder bridge were fabricated. The specimens were tested with four different shear span lengths to determine the horizontal shear resistance of the deck under a static monotonic loading. For comparison purpose, two reinforced concrete decks were also fabricated and tested. The horizontal shear resistance of the proposed deck system was calculated using the m-k method.

• Journal of Korean Society of Steel Construction
• /
• v.28 no.1
• /
• pp.35-42
• /
• 2016

This paper presents the structural analysis of two-span structures constructed by incremental launching method to traverse the existing facilities. The structure with a relatively short launching span can not be secure the structural stability caused by excessive deflection and overturning prior to reaching the maximum strength, because the length of the other span is different or the rear structure is not continuous. In order to estimate the stability of the construction stages of deflection and the overturning, the structural analysis was carried out. The parameters of the analysis is launching span ratio of the launching nose and the upper structure, weight ratio and so on. From the analysis result, the effects of parameters were investigated and a deflection formula of the launching nose and the condition of the overturning of structure were proposed.