• Journal of the Korea Concrete Institute
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• v.17 no.5 s.89
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• pp.843-852
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• 2005

Presently, test results and stress-strain models for poorly confined high-strength columns, more specifically for columns with a tie volumetric ratio smaller than $2.0\%$, are scarce. This paper presents test results loaded in axial direction for square reinforced concrete columns confined by various volumetric ratio lateral ties including low-volumetric ratio. Test variables include concrete compressive strength, tie yield strength, tie arrangement type, and tie volumetric ratio. Local strains measured using strain gages bonded to an acryl rod. For square RC columns confined by lateral ties, the confinement effect was efficiently improved by changing tie arrangement type from Type-A to Type-B. A method to compute the stress in lateral ties at the concrete peak strength and a new stress-strain model for the confined concrete are proposed. Over a wide range of confinement parameters, the model shows good agreement with stress-strain relationships established experimentally.

• Communications of the Korean Mathematical Society
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• v.30 no.2
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• pp.81-92
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• 2015

In this paper, we aim at establishing a generalized fractional integral version of Gr$\ddot{u}$ss type integral inequality by making use of the Gauss hypergeometric function fractional integral operator. Our main result, being of a very general character, is illustrated to specialize to yield numerous interesting fractional integral inequalities including some known results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.11-16
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• 1999

Discharge characteristics research for high voltage and large current electric machinery design, the development of ozonizer with high yield and efficiency for environment improvement, generation of plasma & laser and EMI EMC are research fields of Enersy & Environment Electromagnetic Laboratory(EEEL) in the school of electrical & electronic engineering of Yeungnam University. On this paper, we would like to introduce the discharge and ozone generation characteristics of ozonizers designed and manufactured by EEEL. After starting research for fluid gas discharge characteristics early in the 1980's, high voltage nozzle(HVN) type ozonizer, neon lamp(Nelamp) type ozonizer, ozone lamp(Olamp) type ozonizer and multi-discharge type ozonizer(MDO) have been investigated since 1990.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.7
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• pp.311-315
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• 2002

Chemical mechanical polishing (CMP) process was required for the global planarization of inter-metal dielectric(IMD), inter-level dielectric (ILD) layers of multi-layer interconnections. In this paper, we studied the characteristics of polishing pad, which can apply shallow trench isolation (STI)-CMP process for global planarization of multi-level interconnection structure. Also, we investigated the effects of different sets of polishing pad, such as soft and hard pad. As an experimental result, hard pad showed center-fast type, and soft pad showed edge-fast type. Totally, the defect level has shown little difference, however, the counts of scratch was detected less than 2 on JR111 pad. Through the above results, we can select optimum polishing pad, so we can expect the improvements of throughput and device yield.

• Korean Journal of Agricultural Science
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• v.39 no.1
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• pp.35-41
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• 2012

This research was conducted to investigate the influence of organic bed soil substrates on growth and yield of organically grown ginseng transplantation in a shaded plastic houses. The pH and EC of the substrates used for this study were 5.93-6.78 and 0.03-0.15 dS/m, respectively. The concentrations of NH4-N and $NO_3$-N were 14.01-68.63 mg/L, 5.60-58.83 mg/L respectively. and the average quantum in the shaded plastic houses was 11-15% of natural light. The maximum temperature in the shaded plastic houses is higher ($3-7^{\circ}C$) than that of outside open field from the last part of April to early in August. Emergence date of ginseng was on March 21 in the mongolian type shaded plastic house, and was on March 29 in normal type shaded plastic house. Both roots and shoot growth of ginseng were excellent in the bed soils with PPV-2, compared with other compounds used. We concluded that the PPV-2 could be promising a good bed soil substrate for organic ginseng cultivation in shaded plastic house.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.1
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• pp.86-92
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• 1992

Green buckwheat seedlings have been used as a pollution free vegetable and medicinal crop for a long time. Some of the reasons are the rapid growth rate, the high protein and rutincontent, and a more favorable ratio of leaf to stem than mature plants. Off-crop season cultivation techniques were developed for growing the young and green buckwheat vegetable of higher quality and yield, and for its increased value-added income. The effects of planting season, seeding rate, seed bed soil fertility and type, and seedling growth period on yield and rutin content were determined for vegetable and medicinal use. The young vegetable yields. in the off season culture ranged from 2.62t/ha to 22.7t /ha. The highest vegetable yield was 22.7t /ha for 25 days old seedlings grown in the polyethylene film tunnel from March 30 to April 25, 1991 where seedling rate was 360kg /ha. Buckwheat vegetable quality and income were dependent upon planting season, seeding rate, growing duration and temperature, and facilities of raising seedlings. Protein content of buck-wheat seedlings was from 21.5% to 17.2%. Rutin content of the vegetable was 53.9～31.7mg /100g for the whole plant in average. The protein and rutin content was significantly varied due to the different environmental conditions including fertility and type of seed bed soil, growing duration, temperature of the green house, and polyethylene film house and tunnel.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.97-101
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• 1969

The experiment about the mixed sowing of two different growth type varieties of barley-Buheung and Suwon＃18-has been conducted to determine the competition effect between two varieties, and its results are as follows: 1. Buheung-long stem variety-showed higher survived ratio than Suwon＃18-short stem variety- and that tendency was significant under the high fertilized condition. 2. When tow varieties-Buheung and Suwon＃18-were sowed together, the culm length of Buheung was shorter than the single planted Buheung and that of Suwon＃18 was onger than the single planted Suwon＃18, however, the panicle length showed the opposite tendency to the culm length variation. 3. The number of panicles and the number of grains did not show any differences among the treatments. 4. In case of the single sowing, Suwon＃18 showed higher grain yield under the common fertilized condition but Buheung showed significantly increased grain yield under the heavy fertilized condition, however, in case of the mixed towing of two varieties, the grain yield was significantly increased in heavy fertilized plots than standard fertilization. 5. The competition power was significantly superior in Buheung to Suwon＃18 and this tendency was rather definite according to the fertilizer application.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.4
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• pp.37-48
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• 1984

The yield-line analysis is used for earring out the limit analysis of reinforced concrete slabs which are for example like those of vertical walls of tanks subjected to the loads of hydrostatical type. It is considered both isotropic and orthotropic reinforcement using the coefficient of orthotropy with different edge conditions. The yield-line analysis is carried out by using the vertical work method and four collapse mechanisms including the fan mechanisms which is more realistic than over diagonal mechanisms is considered. It is found that the fan mechanisms are more complicated than ever simple diagonal mechanisms which have used for the orthotropically reinforced concrete slabs subjected to hydrostatic pressures. Especially Horton's study is extended in this study, and they are formulated to the constrained multi-variables nonlinear optimization problems, which are solved by the Rosen-Brock Hillclimb Procedure Program and are more critical.

• Journal of Korean Society of Steel Construction
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• v.11 no.1 s.38
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• pp.43-54
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• 1999

The divergence connection between steel circular tubes is widely used in such structures as factory facilities, steel circular hollow section truss, and off-shore tower. Steel circular hollow section (SCHS) have close section, and it makes their per-unit production expense higher than open sectioned products like L-shape, H-shape steels, but the sectional resistance of SCHS against vertical compression and torsion is very high. Despite the structural merits of SCHS, however, many engineers dislike to use them in their design because of uncertainty regarding the stress distribution and deformation behavior at their connections. Therefore, this thesis dealt with X-type connections, the most common forms of connection, and studied their load-deformation relationship. It observed how to show the load-deformation relationship at steel circular tube connections according to the diameter-thickness ratio (D/T) of the chord and diameter of branch-diameter of chord ratio (d/D) and suggested prediction yield load using by ring analysis method.

• Journal of Adhesion and Interface
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• v.7 no.4
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• pp.1-9
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• 2006

The single lap joint is the most studied joint in the literature in terms of both theory and practice. It is easy to manufacture and the lap shear strength is a useful value for strength assessment and quality control. Simple design rules exist such as the one present in standard ASTM 1002 or in a recent paper by Adams and Davies. The main factors that have an influence on the lap shear strength are the type of adhesive, i.e. ductile or brittle, the adherend yield strength and the overlap length. The overlap increases the shear strength almost linearly if the adhesive is sufficiently ductile and the adherend does not yield. For substrates that yield, a plateau is reached for a certain value of overlap corresponding to the yielding of the adherend. For intermediate or brittle adhesives, the analysis is more complex and needs further investigation. In order to quantify the influence of the adhesive, the adherend and the overlap on the lap shear strength, the experimental design technique of Taguchi was used. An experimental matrix of 27 tests was designed and each test was repeated three times. The influence of each variable could be assessed as well as the interactions between them using the statistical software Statview. The results show that the most important variable on the lap shear strength is the overlap length followed by the type of adherend.