• Biomedical Science Letters
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• v.7 no.4
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• pp.211-216
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• 2001

This studs was carried out to evaluate KBrO$_3$-induced acute toxicity by clinical pathological parameters in rats. Fourty rats were divided into 4 groups including normal group and three KBrO$_3$-treated groups with doses of 200, 300, and 400 mg/kg, p. o., respectively. Creatinine and BUN were increased remarkably by KBrO$_3$ at 400 mg/kg, respectively (p<0.05, p<0.01). Phosphorus content increased two times the control at 400 mg/kg (p<0.05). Osmolarity was increased, whereas $CO_2$ content showed decrease at 400 mg/kg, respectively (p<0.01, p<0.05). Histopathological findings also showed dose-dependent renal failure. On the other hand, AST was increased three times the control at 400 mg/kg (p<0.01). WBC was increased by KBrO$_3$ depending on the dosage. Platelet was decreased at 200 mg/kg, whereas it was increased at 400 mg/kg (p<0.05). The results above suggest that clinical pathological parameters could be used as indices for the evaluation of KBrO$_3$-induced acute toxic reponse occuring in not only kidney but other organs including liver, when the dosage is as high as 400 mg/kg.

• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.589-600
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• 1997

Cold-formed deck sections are used in many composite floor slab applications wherein the steel deck serves not only as the form for the concrete during construction but also as the principal tensile reinforcement for the bottom fiber of the composite slab. This paper provides the results of an experimental study performed for the composite slabs with the new shaped deck plates with the locking ribs, the dove tails, and the powerful embossment, which are the mechanical means to improve positive interlocking effect between the deck and the concrete. A total of 28 specimens are tested to investigate the composite effects between the concrete and metal deck plate. Important parameters in this are the span length, the thickness of the deck plate, support condition, and whether shear studs are placed at each support or not. The test results are summarized for the maximum load and failure behavior for the specimens.

• Journal of Korean Society of Steel Construction
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• v.19 no.3
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• pp.247-258
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• 2007

This paper describes the results of an experimental study on the new type of encased composite beams that use deep deck plates, which could reduce the story height of buildings by controlling the bottom flange of steel beams. The profiled steel beam was thus developed. It was advantageous to the long span of the buildings. Seven full-scale specimens were constructed, and simply supported bending tests were conducted on the encased composite beams with different steel plate thicknesses, with and without shear studs, reinforcing bars, and web openings. The test results showed that the encased composite beams that were developed in this study had sufficient composite action without additional shear connectors due to their inherent shear-bond effects between the steel beams and concrete.

• Journal of the Korean Wood Science and Technology
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• v.19 no.4
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• pp.34-42
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• 1991

Protection of tropical forest affects on significant reduce of tropical hardwood supply, and softwood resources will be increasingly important for the timber security in Korea. U.S. softwood log was most favorite species for Korean softwood log importers in overall import conditions except price stablization and consistency of export policy. Reduced export volume from Pacific Northwest to Korean market has been immediately replenished by rediata pine from New Zealand and Chilean plantation. Siberian timber will hardly play major roles in Korean timber market unless budding structure. softwood plywood and softwood furniture uses are enhanced. Recent rapid rise of labor cost and reducing tariff rrate in Korea provided better opportunities for import lumber in building materials market. Dry dimension lumber was relatively profitable when processed from import U.S. soft-wood log while green lumber was favorable products processed from radiata pine log in Korean lumber market. This means U.S. softwood lumber would have better opportunity to market for '2${\times}$'4 studs when wood frame housing is introduced. On the other hand while radiata pine is competitive on temporary construction lumber such as supporter and concrete forming frame in Korea. Shortage of raw material for the new capacity of board plants in Korea will be it bottle neck. Major log export countries to Korea as U.S. New Zealand and Chile showed high trade intensity indices of composite hoard produces for Korean market. As Korea efforts to diversify import sources, and tariffs are reduced to 8% as scheduled by 1994. countries of scoring higher comparative advantages as Portugal. Brazil, Austria as well as New Zealand will have better opportunity to penetrate into promised Korean composites hoard market.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.3
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• pp.189-196
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• 2004

The RC wale-steel beam stud connection may have smaller moment and shear resistance because the tensile and shear capacity of the studs are limited by the depth of RC beam. Especially, they are subjected to compressive axial load. This paper describes the experimental works to develop the connection details of RC wale-steel beam joints subjected to shear and axial loads. Shear connectors developed in this study are closed C type deformed bar, opened C type deformed bar, and U type deformed bar. From shear test, the shear performance of RC wale-steel beam joint with the developed connectors are compared with the stud connection. Test results indicated that the developed connectors were very effiecive to increase the shear strength.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.491-496
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• 2015

The headed studs used extensively for steel-composite construction are specified as SS400 in the current Korean Standard specification considering the welding condition. And the corresponding equation for the shear force calculation is limited for the use of compression strength of concrete below $300kgf/cm^2$. However, it is expected that the high strengthening and precasting of both steel and concrete due to the necessity of shear connector or other connecting material for the combination of steel and concrete. Therefore, the experimental results obtained during the development process of high strength stud for the connection of high strength concrete and the steel member are reported in this paper. Also the effectiveness of newly developed shear connector using pipe(pipe stud) to increase the stiffness of a stud is verified by comparing both the stiffness and the strength with common stud bolt through the welding ability, mechanical characteristics and experimental investigation.

• Korean Journal of Construction Engineering and Management
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• v.14 no.3
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• pp.33-41
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• 2013

This study used TRIZ methodology to develop a new steel stud for load bearing or non-load bearing walls. Technical contradiction of high strength with high insulation performance can be solved by TRIZ. We suppose a new shape of high-strength insulated (HSI) Stud. This study showed TRIZ can be usefully applied to the development of new construction materials by solving technical contradictions. Insulation performance of HSI stud can be improved approximately 12% compared to the standard KS stud. Although up to 3.9% of the flexural strength degradation is expected, compressive strength of HSI studs are improved from 4.1% to 8%. In conclusion, improved thermal performance and higher strength can be expected for the HSI stud developed using TRIZ.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.5
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• pp.642-653
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• 2002

The purposes of this studs were 1) to identify web navigation values and classify consumers based on these values and 2) to determine differences between consumer groups and between types of shopping mall in evaluation of website attributes when shopping apparel. The data were collected via a self-administered questionnaire from 204 male and female students who experienced shopping at the website, living in Cheju and analyzed by factor analysis, cluster analysis and t-test. Two factors of navigation value were found and labeled as; information value and entertainment value. Two groups were identified based on navigation value; users of information value (53%) and users of entertainment value (47%). Significant differences between two groups were found in evaluating website attributes selling products of various types regarding apparel products and processes for information search, order and payment. However, for shopping mall website selling only apparel products, differences between two groups were not significant in evaluating most attributes except for two items to evaluate apparel products. Differences between shopping mall types (shopping malls selling products of various types and selling only apparel product) were significant in evaluation of internet users of information value regarding attributes of apparel products while differences between shopping mall types were not significant in evaluation of users of entertainment value regarding all attributes. Internet users of information value showed favor to shopping mall website of department store type chi e internet users of entertainment value showed favor to shopping mall website selling only apparel products.

• Journal of Animal Science and Technology
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• v.52 no.6
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• pp.467-473
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• 2010

A total of 4,323,781 records for informal 16 primary linear descriptive traits of dairy cows in Holstein breed from 1988 to 2007 in USA were analyzed to estimate adjustment factors for lactation number and stage. While all factors in the model were highly significant (P < 0.01), major influences on linear type traits were due to lactation number and stage. The frequencies of lactation number 1 through 6 were 58.6, 22.0, 11.8, 4.8, 2.1, and 0.8%, respectively. Further, the frequencies of lactation stage were 0.7, 76.9, 15.3, 4.9, and 2.1%, respectively, for springing, early, medium, late, and dry. To adjust 16 linear traits (stature, dairy form, strength, body depth, rump width, rump angle, legs rear view, leg set, foot angle, fore udder, rear udder height, rear udder width, udder support, udder depth, and front teat placement), additive and multiplicative adjustment factors of lactation number (lactations 2 to 4) and stage (springing, medium, late and dry) were estimated with the solutions in the generalized linear model, assigning lactation 1 and stage early as base class. Additive adjustment factors of lactation number ranged from -1.23 to 2.908, while multiplicative factors ranged from 0.853 to 2.207. Further, additive and multiplicative adjustment factors for lactation stage ranged from -0.668 to 0.785, and from 0.891 to 1.154. Application of adjustment factors to 20 randomly sampled sub-data sets produced the results that additive adjustment factors for both lactation number and stage reduced more mean square of lactation number and stage over 16 linear traits than any combination of adjustments, and leaded additive adjustment factors for both lactation number and stage as a choice of methods for adjustment of informal 16 primary linear type traits collected by classifiers of AI studs.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.4
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• pp.38-47
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• 2013

For the joint connection of the precast steel grid composite decks, the prefabricated joint which is composed of concrete shear key and high-tension bolts was already proposed. In this study, for the purpose of increasing the bending stiffness and bending strength of the proposed prefabricated joint section details of the proposed joint are modified, and through experimental tests the bending performance, such as stiffness and strength of a modified joint, is compared with those of the proposed joint. Test and analysis results show that the shear cracks in the concrete shear key are clearly reduced by the strengthening of the shear key using shear studs and additional rebars. According to analysis results of the moment-curvature relationship, bending stiffness of the modified joint is about 47% greater than the stiffness of the proposed joint. Furthermore, the modified joint has about 32% greater bending strength than the proposed joint. Compared to specimens without the joint the modified joint has same or slightly higher bending strength, but about 37% lower bending stiffness.