• Journal of Korean Society of Steel Construction
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• v.30 no.1
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• pp.59-66
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• 2018

In this study, the parametric analysis for the buckling behavior of plates stiffened with the new type(${\Box}$ type) ribs was performed. Changes of the buckling capacity according to dimensions of ${\Box}$ type ribs show certain behaviors, so that the system to find the section of ${\Box}$ type ribs under the specific buckling capacity can be proposed. Applying this system to the steel deck of existing bridges, more economic sections of ${\Box}$ type ribs rather than that of closed ribs can be obtained. Therefore, the economic section of steel deck having the required buckling capacity can be designed by using the proposed system of ${\Box}$ type ribs.

• Geomechanics and Engineering
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• v.12 no.2
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• pp.295-312
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• 2017

Cast in situ and grouted concrete helical piles with 150-200 mm diameter half cylindrical ribs have become an economical and effective choice in Shanghai, China for uplift piles in deep soft soils. Though this type of pile has been successful used in practice, the reinforcing mechanism and the contribution of the ribs to the total resistance is not clear, and there is no clear guideline for the design of such piles. To study the inclusion of ribs to the contribution of shear resistance, the shear behaviour between silty sand and concrete slabs with parallel ribs at different spacing and angles were tested in a large direct shear box ($600mm{\times}400mm{\times}200mm$). The front panels of the shear box are detachable to observe the soil deformation after the test. The tests were modelled with three-dimensional finite element method in ABAQUS. It was found that, passive zones can be developed ahead of the ribs to form undulated failure surfaces. The shear resistance and failure mode are affected by the ratio of rib spacing to rib diameter. Based on the shape and continuity of the failure zones at the interface, the failure modes at the interface can be classified as "punching", "local" or "general" shear failure respectively. With the inclusion of the ribs, the pull out resistance can increase up to 17%. The optimum rib spacing to rib diameter ratio was found to be around 7 based on the observed experimental results and the numerical modelling.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.381-388
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• 2000

The steel piers and the concrete-filled steel piers, in spite of reasonable strength, high ductility, small section, and fast construction, have not been considered as the alternatives to the RC piers even in the highly populated urban area where aseismic safety, limited space and fast construction are indispensably required. In this paper, a steel pier and 4 box type concrete-filled steel piers were tested with the quasi-static cyclic loading to estimate the ductility and the strength. Additional devices such as base rib, turn-buckle, and anchor bolted added at the to increase the ductility with minimum additional cost. The result showed that the concrete filled-in steel piers had higher energy absorbtion and strength than steel piers had, but also showed that slight overlooking in the design and fabrication could lead to the abrupt fracture just after small local buckling at the bottom.

• Journal of the Korea Concrete Institute
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• v.23 no.3
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• pp.303-310
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• 2011

To replace a steel box bridge for constructions of medium span bridges in Korea, the Hybrid Truss Bridge (HTB) is being considered as an alternative bridge type. The core technology of HTB is the connection joint that links the concrete slabs and steel truss pipes. Various construction companies in Japan have developed unique connection systems and applied to the real bridge constructions after verifying their performances through the experimental evaluation. In this study, the fatigue test of a hybrid truss girder has been performed in order to verify the newly proposed hinge type connection joint`s static and fatigue capacities. Through this fatigue test results, it is founded that the structural detail to improve the fatigue capacity should be developed. The hinge connection system with circular ribs has been proposed by means of structural finite element analyses. And then the fatigue test for this connection joint has been performed and it is proved that this connection joint has enough fatigue capacity. Finally, it is expected that the hinge connection system with circular ribs developed by in this study can be easily applied to the real bridge.

• Korean journal of food and cookery science
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• v.24 no.4
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• pp.525-535
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• 2008

This survey was conducted to assess dining-out behaviors and menu preferences of university students in the Seoul area. The results were as follows: 1. 65.2% ate out rarely for breakfast and 73.1% ate out frequently for lunch, whereas 20.9% occasionally ate out for lunch. The frequency of dining out for breakfast was influenced by age, gender, and major but the frequency of dining out for lunch was significantly correlated with age(P < 0.01). 79.2% of females dined out frequently, but 62.3% of males reported doing so(P < 0.001). 65.2% ate out frequently for dinner and 31.6% did so occasionally. 34.2% dined out frequently for snacks, and 53.5% did so occasionally. 2. Factors to consider in dining out were as follows: taste > preference > price > persuasion > nutrition. The motivations for dining out were as follows: convenience > favorite food > difficult to prepare lunch box > difficult to carry lunch box > habit. This factor was correlated significantly with age(P < 0.05) and residence type(P < 0.001). Problems with dining out were listed as follows: unbalanced nutrition > price > sanitation > variety of menu > taste. This factor was correlated significantly with age(P < 0.05), alcoholic beverage use(P < 0.01) and smoking(P < 0.01). 3. Foods selected for meals when dining out were as follows: Korean style > Western > Japanese > noodles > Chinese. The expense(in won) of dining out for lunch was as follows: 3,000${\sim}$5,000 > 2,000${\sim}$3,000 > over 5,000 > under 2000. Problems to be corrected in Korean-style food were as follows: variety of menu > price > using personal dish. 4. Korean foods preferred in each cooking style when dining out were as follows: beef rib > kimchi-jjigae > bulgogi > doenjang-jjigae > bibimbab. Chinese foods selected were as follows: tangsuyuk > jajang myeon > jjambbong > gganpunggi > bokeumbab. Preferred Western foods were as follows: spaghetti > steak > pork cutlet > pizza > ribs > chicken. Preferred Japanese foods in meals when dining out were as follows: sushi > hoe > udong > pork cutlet > soba. Preferred noodle foods selected when dining out were as follows: ddukboki > ramyeon > mandu > guksu > sundae > gimbab >. Preferred baked foods for dining out were as follows: cake > pizza > loaf bread > baguette > sandwich > hamburger > doughnut > cream bread.